Experiences with Auto EQ
Posted by: schofiel
Experiences with Auto EQ - 29/08/2004 19:07
Well, it works for me! And - guess what - it turns out reasonable EQ presets, which genuinely sound better in my car. With a second set of ears listening, there was general agreement it makes the sound system sound much better. Worth persisting with, I'd say!
Here's the story:
- downloaded the Auto EQ test audio files to a new playlist, and made sure they were ordered by using ALT-drag to set them sequentially in correct playback order
- synched
- went to the car and plugged in the mic, making sure it clicked home properly against the face of the socket on the harness (IMPORTANT!)
- positioned the mic next to my head over my shoulder
- turned on the ignition, turned off the ventilation and other noisy bits
- plugged in Erik the Empeg and waited to boot
- went into HiJack, turned off Bass and Treble adjust
- turned off Auto Level Adjust
- dropped out of HiJack
- using the rotary, turned off beeps, cross fade, loudness, and centred the fader and balance
- in the main menu, chose Playback and turned off Repeat, Shuffle, etc.
- went to the playlist with the auto EQ test files and selected them for play with the arrow (Play All) then hit pause.
- went to the equaliser
- selected an unused equaliser preset (#16 in my case)
- selected locks to be independent
- selected channels to be 2 (Stereo) (IMPORTANT!)
- set the volume to -30 dB
- held our breaths, and....
- selected Auto EQ and away we went!!!! (Rumble Rumble Whirr Whirr Wheee Wheee Hisss Hisss)
It turned out (first try) a pretty boomy result (mic between the seats in the air at head height), then a much improved version (different preset, mic on driver's headrest). We then re-positioned it on the passenger's headrest (different preset again) and it went crazy - clicks, pops, howls, screams, all sorts of rubbish - but all on right channel. Left channel worked OK.
Tried it again, on the driver's side, and experimented with the volume a bit, and finally got a run of several similar settings that all improved the sound.
Observations:
- You need to set the volume at a reasonable level, no more than -15 dB. We tried 25 - 20 and got good results, but 15 seems to be the max before it flips it's gourd and starts playing "Apocalypse Now" soundtrack effects
Any lower than about 35 didn't work (no adjustments made). As a general rule, the small VU meter in the top left is your friend - it tells the truth about what the unit can "hear". If the gain is too high, it goes bezerk - beware of this.
- You need to select the playlist with the test tracks in, or you get silence
- The tracks have to be ordered in emplode by sequence using ALT drag or there will be serious confusion
- I doubt that many of the microphone connectors on the sleds have ever been used. Mine seemed to prevent a clean entry of the mic plug: it finally clicked home after a hefty shove and the face of the plug finally butted up against the socket face. If the mic isn't connected, the empeg ain't listening - check the VU meter again to see if there is sound coming in.
- DON'T be tempted to choose the Microphone as an input Source from the main menu - it hangs up the player and looses any EQ settings you might have!
- it seems sensitive to mic positioning, but it IS sensitive and produces good results with a little experimentation. Positioning the mic near fabric seems to damp it's response and make it more stable.
- exit menus cleanly after you have done this and shut down the player properly or you will lose your shiney new EQ settings!
Have fun. I hope this little checklist helps you get it to work. If you have any questions, post here and I'll try it out on my own player and see if I can give you answers. I know Andy Marriot has had problems getting it to work, and if I read his story right, it sounds like he has got the gain high and maybe the mic positioned wrongly. Good luck!
PS. One thing I noticed is that it does tend to make rather alarming clicks and pops as it changes between left and right tests, and between tracks. Don't be too alarmed - it seems to work anyway. Andy, if you are getting clicks and silence for a few seconds in between, you might actually have the gain so low that the empeg can't hear itself. Check your volume level again anyway.
Posted by: andym
Re: Experiences with Auto EQ - 29/08/2004 19:44
Thanks for such an in depth investigation of this Rob. When I get round to replacing the blown drivers in my car I might give this another go.
Posted by: webroach
Re: Experiences with Auto EQ - 30/08/2004 00:26
I'll second the "Thank You" for the in-depth on the Auto-EQ. You should write the final "How To" on it.
Granted, I might find it more interesting if the Alpha that has Auto-EQ was available to those of us who, be it for commitment or financial reasons, couldn't go to Amersfoort.
But hey, life goes on.
Turn off the Left/Right time alignment too.
Thank you for posting this!
Posted by: genixia
Re: Experiences with Auto EQ - 30/08/2004 01:18
I suspect that the clicks and pops may be due to the player not being muted when EQ changes are made.
Quote:
The equalizer gain must be changed in steps of maximum 1dB to prevent switching noise. If the change is equalizer shape is big, an additional audio muting is preferred to prevent clicking noise.
SAA7705H DSP User Manual, Section 9.1.6.4, Pg104.
Posted by: tfabris
Re: Experiences with Auto EQ - 30/08/2004 01:51
WHAT MICROPHONE DID YOU USE?!!?!?!?!
Posted by: SonicSnoop
Re: Experiences with Auto EQ - 30/08/2004 02:14
Is there a v2 that has the AutoEQ added to it? was that the 2.01 I saw something about? cant remember. If it does I would really like to try this out.
Posted by: genixia
Re: Experiences with Auto EQ - 30/08/2004 02:15
No. It is only in v3a8.
Posted by: SonicSnoop
Re: Experiences with Auto EQ - 30/08/2004 02:21
That sux. I wonder, if you installed the v3a8 ran autoeq, could you take down the results and then load v2 and set the eq to that and it be the same? either way this is very interesting. I like the stability of v2 but am very tempted to persue trying v3.
Posted by: schofiel
Re: Experiences with Auto EQ - 30/08/2004 05:41
Yeah, but don't forget - this is my empeg listening to itself through my speakers and amp combination in my car. If I give you the preset it generated, and you entered it onto your empeg (with different car, speakers and amp) then it just isn't going to produce meaningful results.
You could install V3a8, run AEQ, and then go back to V2 while retaining your new EQ setting
Posted by: schofiel
Re: Experiences with Auto EQ - 30/08/2004 05:42
Have I missed this on the thread? When did this happen?
Posted by: tfabris
Re: Experiences with Auto EQ - 30/08/2004 06:34
Quote:
If I give you the preset it generated, and you entered it onto your empeg (with different car, speakers and amp) then it just isn't going to produce meaningful results.
I think he meant if he did it himself. When he said "you", I think he meant it in the generic sense. Replace "you" with "one" and I think that's what he meant.
So to answer his question: Yes, one could conceivably run AutoEQ on V3a8, and then downgrade to V 2.0 final, and use those EQ settings on the more stable non-beta version.
I'm pretty sure that the two software versions share the same EQ data storage area in the same file format, so one doesn't even need to hand-write settings. One just does it and it "keeps".
Tony, if I were to do the AutoEQ on a test player, could I transfer one file via FTP that would copy the EQ settings? I'm thinking of using my old player for EQ duty for my car and for a few of my friends. It would be nice to do a quick FTP transfer rather than writing the settings on paper.
Posted by: schofiel
Re: Experiences with Auto EQ - 30/08/2004 10:22
Am I being daft here and completely missing the point? The presets produced by AEQ are unique to
your car and audio setup and no-one else's, so what's the point? I think I must have lost the plot here somewhere.
Posted by: SonicSnoop
Re: Experiences with Auto EQ - 30/08/2004 10:33
Yeah that is exactly what i ment.
Posted by: pgrzelak
Re: Experiences with Auto EQ - 30/08/2004 10:35
The thought is to use a spare empeg with v3a8 loaded on it, preform the autoEQ and write the settings down. Then the empeg that is normally used in that same car would be adjusted to match those settings. This is handy if you do not want to worry about running alpha code while driving. Basically, you are finding the autoEQ tuning for that car, and then copying them to the empeg that will run in that environment.
Posted by: SonicSnoop
Re: Experiences with Auto EQ - 30/08/2004 10:35
I think what he is refering to is setting up one empeg as an autoeq box, take it to cars run it and then once it has the settings take it in the house and transfer the eq settings file over to another empeg so the owner of that empeg doesnt have to install the v3. I could be wrong but thats what it sounded to me.
I would take "my" empeg and insert it into "their" car's sled and run the AutoEQ. Then I would copy those settings to "their" empeg. Rinse and repeat on next car.
We are either too chickensh
it or don't have enough RAM to run alpha w. such a large database. The other empeg users in my family and my friends have never done any of their own software updates - I've done all their upgrades for them. This would just be easier.
ps - This censoring is hard core! It cuts everything before the offending word!
Posted by: tfabris
Re: Experiences with Auto EQ - 30/08/2004 14:29
Quote:
Tony, if I were to do the AutoEQ on a test player, could I transfer one file via FTP that would copy the EQ settings?
Not directly, as it's not stored in a loose file. It's stored as raw binary data on the scratch partition.
I think it's possible that a carefully-typed shell command could create a file from that scratch data, and then that file could be transferred to the other player, then a corresponding command could write that data to the new player's scratch partition. Sounds like a lot of trouble, though, and it might be easier and faster just to either (a) write down the settings, or (b) upgrade and downgrade the user's player.
Or... (c) just do the EQ by ear... I still can't get the auto-EQ working right and sounding good. Still waiting to find the right microphone.
I just have no luck adjusting the EQ by hand, even I know the wanted values. The UI is so damned confusing to me! (my fault)
Posted by: FireFox31
Re: Experiences with Auto EQ - 03/09/2004 16:03
Rob, thanks for posting that info! That's just the verification I needed to trust that I'm getting accurate results and not making it sound worse.
Quote:
if you installed the v3a8 ran autoeq, could you take down the results and then load v2 and set the eq to that and it be the same?
That's exactaly what I plan to do. Install V3a8 on my spare, run AutoEQ, then copy the settings down and input them by hand into my main player.
And to second Tony's question, what mic did you use? And is it available in the US (since Farnell doesn't seem to ship to the US)? And does it require assembly (because I have no soldering iron)?
And lastly, I *really* wonder if AutoEQ could be used at home to configure the home setup!! Ooh, I can't wait to try. Just ... need ... the mic!
Posted by: SonicSnoop
Re: Experiences with Auto EQ - 04/09/2004 01:37
yea im very interested in what mic to use that i can get in the states also.
Posted by: schofiel
Re: Experiences with Auto EQ - 08/09/2004 08:11
I didn't realise that this issue with getting the mic would be such a big deal. What sort of interest would there be if I could buy and make up a mic assembly with cable and plug? It would be entirely dependent on interest and you'd proably have to pay either by bank transfer or paypal. No idea what it would cost, but it would be materials and postage.
I know a number of us would be interested... Having the alpha (or a beta) with this feature more accessable to the userbase would help.
Posted by: Shonky
Re: Experiences with Auto EQ - 08/09/2004 09:45
I'd certainly be interested in a prebuilt one (of course dependent on price). I can't see them being that expensive though.
Posted by: andym
Re: Experiences with Auto EQ - 08/09/2004 10:02
Let's hope Maplin don't pull a fast one and drop the item. It's happened before, very annoying.
Posted by: mlord
Re: Experiences with Auto EQ - 08/09/2004 10:43
I think the assembled mic + cable + plug + postage could sell for EU15 or so, all inclusive -- a great convenience (and a standard mic) for all of us, and the price might just recover all of your costs (barely).
Do others agree?
(I already have one)
Posted by: Shonky
Re: Experiences with Auto EQ - 08/09/2004 10:56
So which is the standard mic? Mark are you using the Maplin QY62S microphone or an "equivalent"?
According to
this post, that's what was used for development.
Posted by: mlord
Re: Experiences with Auto EQ - 08/09/2004 11:15
I have one of the Malpin mics here, which any one is welcome to borrow when in the country -- we can trade it back and forth by padded post envelopes. But if you're not in Canada, then nogo -- our customs folks will intercept it and start charging ridiculous fees.
Cheers
Posted by: oliver
Re: Experiences with Auto EQ - 08/09/2004 13:35
I'd need 3-5 mics, for my car, plus a couple friends. I'd rather get the empeg approved mic, this way we wouldn't need to do any config for the exact mic.
Posted by: robricc
Re: Experiences with Auto EQ - 08/09/2004 13:37
I'd want one.
Posted by: mcomb
Re: Experiences with Auto EQ - 08/09/2004 15:04
Quote:
I'd want one.
Me too, assuming the price is reasonable and nobody comes up with a US source. It might make more sense for you to source a batch and send them to Stu or somebody over here to resell.
-Mike
Posted by: Daria
Re: Experiences with Auto EQ - 08/09/2004 15:12
I'd be up for 2 of em.
I think this will help with any (hopeful) future development.
Posted by: adavidw
Re: Experiences with Auto EQ - 09/09/2004 07:14
I would definitely buy one in anticipation of the day when the auto-eq feature actually becomes available to me.
Posted by: tfabris
Re: Experiences with Auto EQ - 09/09/2004 15:31
Heck, I'd think that a purchase of the mic should include a copy of the Amersfoort CD.
I'm in for a mic, by the way, if they are made available. I had no luck with the Radio shack parts.
Posted by: jimhogan
Re: Experiences with Auto EQ - 09/09/2004 15:59
Quote:
I would definitely buy one in anticipation of the day when the auto-eq feature actually becomes available to me.
Yup, I'd take 2.
Hmmm, now I just have to talk with Shonky about a vasectomy reversal!
Posted by: Shonky
Re: Experiences with Auto EQ - 09/09/2004 19:26
Quote:
Hmmm, now I just have to talk with Shonky about a vasectomy reversal!
??? What have you cut?
Posted by: tfabris
Re: Experiences with Auto EQ - 09/09/2004 19:48
Mic input on the sled was probably usurped for some other feature such as custom subwoofer output or digital audio out....
Posted by: Shonky
Re: Experiences with Auto EQ - 09/09/2004 20:00
Since he specifically referred to me, he might be noting the fact that the harnesses I built did not have a mic input
At that time I saw no need for it - the VR stuff didn't look like happening. I did supply the spare pins though so if someone wanted it, they could add it reasonably easy.
Simply get a 3.5mm socket on a cable (something like a 3.5mm socket-plug extension cut in half)and crimp it on to the two pins. The crimps can be done with small pliers quite easily if you're only doing a couple.
Either way there was no cutting involved.
Posted by: genixia
Re: Experiences with Auto EQ - 10/09/2004 19:32
Ok, I've been looking at this to see whether anything could be done in the kernel to prevent the transients. I added a hijack menu option to enforce muting whenever the eq was applied. I had thought that this would slow down the manual EQ interface, hence not just enforcing it period. Strangely enough it doesn't and it removes the nastiness that is present when you try to change a bands frequency when a large gain/cut is already applied to it.
However, it does not fix the problem with Auto EQ. And I realised that Auto EQ adjusts in small steps whilst measuring, rather than measuring then applying one large step. This means that as long as you start from a flat EQ, this fix wouldn't do anything to help anyway and in fact may screw up the measurements. So that patch will probably hit the bit bucket - I don't remember anyone complaining about the manual EQ glitch before so it would seem strange to have a hijack option to fix something no one cared about.
Back to Auto EQ, I played the files in XMMS. Sure enough, the transients are present in the files. It sounds like the files were bandwidth limited first and then cut in the time domain, resulting in a square transient at the beginning of the file. I'm guessing that no effort was made to cut at zero crossing points...
Is anyone set up to re-generate the files from scratch?
Looking at the files for the first time, I'm surprised that they are mp3s and not wavs.
I assume Cool Edit Pro could be used to generate the files... any drawback to using wavs?
Posted by: genixia
Re: Experiences with Auto EQ - 10/09/2004 22:00
Only the size, which I don't see as being a problem. JohnnyGee didn't think that mp3 was a problem either though.
It would be interesting to convert the mp3s back to wavs and look at the beginnings/ends of the waveforms though.
Posted by: tfabris
Re: Experiences with Auto EQ - 10/09/2004 22:02
Quote:
any drawback to using wavs?
For the case of the frequency spectrums that AutoEQ is trying to correct for, there is no drawback to using MP3s, and their lowered system resources and cache usage makes it much more logical to use MP3s there. So I'd say stick with MP3s.
Posted by: jimhogan
Re: Experiences with Auto EQ - 11/09/2004 00:53
Quote:
Since he specifically referred to me
Oh, Oh! Brain fart! Brain fart!
I suffered some segment overwrite. I really need to talk with *maczrool* (Stuart, Eutronix) about reverse vasectomey -- what to do with my digital output? or how to add a new Mic input? Sorry!!
Posted by: ecoen
Re: Experiences with Auto EQ - 11/09/2004 03:16
Put me down for one.
I have microphone extension cables wired in two cars that are ready to go!
Posted by: JaBZ
Re: Experiences with Auto EQ - 22/09/2004 02:03
Would
this work for us NZ/Aus users?
Would save me faffing about with the unassembled type..
I found a similar microphone commonly available in the US
here. 70-16,000Hz response. 1000 ohms
Is there any reason we couldn't use a full size microphone or is there an advantage to one of the tiny ones? I don't plan to keep any microphone permanently wired in the car. I just have a 1/8" extension cable running to my armrest and would remove any microphone after use.
Success!
I just got done doing the AutoEQ setup and it went great! I used a $25 clipon lav. mic from RadioShack along with an extension cable so that I can remove the microphone but keep the cord hooked up.
I printed out Rob's post and brought it into the car with me. You have to make absolute sure that you have all the sound features turned off (we have a ton of them!) He managed to include most of them, but you have Auto Volume Adjustment in both HiJack and the empeg software as well as "Stereo Seperation" and "Left/Right Time Alignment" to turn off (empeg and HiJack respectively).
Turn off repeat and shuffle too.
The microphone I picked up is a clipon type, so I clipped it onto my shift, right by my shoulder and set the volume to -20dB.
Posted by: andym
Re: Success with Auto EQ! - 26/09/2004 15:37
Does it sound good though? I kept the curve from one of my more sucessful auto-eqs and compared it to one I did myself. I still prefer the manual one.
All that matters is what you prefer but in my case, the speakers had a lot more detail to them and sounded less "muted". It just brings a flat curve, and that's not what we all want, but it gives a good starting point that makes up for deficiencies in our setups. From there, we can tailor the sound to our tastes.
Posted by: genixia
Re: Experiences with Auto EQ - 27/09/2004 09:58
Ok, so we got to play with Auto EQ a little at the Cinci meet, and I have another observation about the clicks and pops. It is possible for Auto EQ to try and boost the bass response too high such that the audio stage becomes unstable, resulting in oscillation. In EE terms, it looks it's trying to boost below DC.
This appears to be especially prone to happen in cars with a poor bass response to begin with. Auto EQ still trys to get a response, thus causing the problem. This problem could probably be fixed by capping the amount of boost that the bass EQs are allowed to apply, although I haven't determined what level is safe and what isn't.
I only did this experience w. the sound files I created at
www.motorcityimprov.com/autoeq/ but I had no clicks and pops.. Just tones and humms.
Also, my mic had poor bass response (but my system has a subwoofer) so the first band cranked itself to +9dB with AutoEQ. I'm going to bring that number down a bit because it's due to my microphone not picking up that frequency.
Rob also mentioned that having the proper volume level helps. His recommendation of -20dB worked great for me.
Posted by: image
Re: Experiences with Auto EQ - 27/09/2004 13:07
well, per the
faq entry, there should be a celing to prevent clipping, i.e. only adjust with the celing at +0db and lower.
Posted by: genixia
Re: Experiences with Auto EQ - 27/09/2004 14:39
This isn't clipping which is what that FAQ entry addresses. The Auto EQ appears to compensate for this anyway - when boosting on band, every other band is cut a little, presumably to keep the average at 0.
What I think is happening here is that the high dB gain pulls up the boost curve such that there is a positive boost extending below 1Hz, ie to DC. If you look at figure 4 halfway down
this page, perhaps you'll understand what I mean. At low boosts (green line), the boost extends less than at high boost (blue line).
Are you saying that because of the Q (range of frequencies affected by the gain to the left and right of the target frequency) that at high gain, other frequencies are being boosted by two bands? (Hope I'm using the correct terminology here.)
From my notes, here are the values that the AutoEQ sets and adjusts:
Band 1: 25Hz, Q=1.33
Band 2: 40Hz, Q=1.33
Band 3: 63Hz, Q=1.33
Band 4: 100Hz, Q=1.33
Band 5: 160Hz, Q=1.33
Band 6: 520Hz, Q=0.83
Band 7: 800Hz, Q=0.83
Band 8: 2 KHz, Q=0.83
Band 9: 5 KHz, Q=0.83
Band 10: 12.5 KHz, Q=0.83
EDIT: It seems that one should be able to take the values given by AutoEQ and reduce them so that as few fields are given boosts as possible (ie, adjust so you are doing mostly cuts).
edit2: corrected the Q values I had.
Posted by: schofiel
Re: Success with Auto EQ! - 27/09/2004 19:11
This is more or less my impression. I am glad someone has had some success: it's a damn nice feature.
My current impressions - I am sure (and to be honest, having spend some serious pub time with John G) that there is a definite bass bias. and hell! I like it that way!
The change to the sound is not incredible, but definite and a great improvement. I have a lot more vocal clarity and more definite bass. I have had to wind down the initial +9 dB bass boost somewhat, but overall, I would rate the improvement in sound in my car at 100% over most driving conditions. One notiveable side effect: I don't keep turning the volume up and down so much. I can pretty much set the volume level and leave it alone without having to rely on HiJack's excellent compensation tools.
On balance: worth persisting with if you take the trouble to do your preparation properly first. Thumbs up for the biggest single change in empeg player functionality in a long time. Don't forget Peter's incredible 16 bit character set support is also way up there, but seems to have been forgotten in the immediate excitement of AEQ - but it is just as welcome.
But I have a question for you lot. What's the future of software releases going to be like now that Rob has departed? What is going to be available for next year's empeg meet?
I will confess to a serious worry at this point. Your opinions?
I'd be happy with bug fixes at this point, but it looks like the only justification for releases at this point is to test new features...
Posted by: schofiel
Re: Success with Auto EQ! - 27/09/2004 19:40
Given that Rob was the initiator in many cases for recent releases, I can't see much happening from now on, unforch
I think John Graley did the AutoEQ stuff... maybe he can carry the torch?
Posted by: genixia
Re: Experiences with Auto EQ - 27/09/2004 20:18
Yeah, and that is normal.
Q is defined as Fc/Fh-Fl. Fh and Fl are defined as -3dB points. As soon as you boost beyone +3dB you're boosting outside of that range. For a Q=1, Fc=25Hz, those -3dB points are going to be approximately 17Hz and 42Hz. (Estimate - It centers on a logarithmic frequency scale.)
Do negative gain values "pull down" frequencies around it?
Posted by: genixia
Re: Experiences with Auto EQ - 27/09/2004 21:12
Yeah, same curve inverted.
Incidentally, the reason why Auto EQ boosts the 25Hz range so much is that very few setups have much response there at all. I just tweaked Laura's amp settings (professionally installed and totally screwed up...LOL), and in doing so set the sub crossover down to 40Hz for a while - there is very little down there at all - even with a 10" Boston Sub. I figure that anyone without a sub hasn't a chance of getting a response at 25Hz, and Auto EQ should be able to handle that scenario. (If no reasonable 25Hz response is found set flat rather than chasing one)
Quote:
(If no reasonable 25Hz response is found set flat rather than chasing one)
Good idea. Or have two versions of AutoEQ - one for setups with a sub and one without.
Does anyone know how to manually adjust the EQ? I didn't come across instructions in the FAQ. I figured out how to adjust the levels for each band, I just don't know how to adjust the frequencies and the Q setting.. Do I use the remote?
Posted by: schofiel
Re: Adjusting EQ Settings - 27/09/2004 21:47
Yup, you use the remote.
Posted by: tfabris
Re: Adjusting EQ Settings - 27/09/2004 22:26
Quote:
Does anyone know how to manually adjust the EQ? I didn't come across instructions in the FAQ. I figured out how to adjust the levels for each band, I just don't know how to adjust the frequencies and the Q setting.. Do I use the remote?
If I recall, the front panel also works. You get to the frequencies and the Q by doing the knob-press. You can glean how to do it from looking at the button press functions in the button guide.
Looks like I have to update that guide to include the knob press function when in the EQ editor. I've got it for the remote, not for the knob.
Okay, I found that the Visuals button toggles between Gain, Frequency and Q but I can't get the thing to select a frequencies below 50Hz...
.
Rob, I noticed I did a few things differantly than you...
a) I never selected the AutoEQ playlist - the player was able to queue these up on it's own based on the tags.
b) I locked my Right and Left channels... I think that's why I was getting fewer pops and clicks.
I just re-ran the test with the channels independant and the results were pretty interesting! I wonder which is more exact since during real playback, the speakers' output would seem to effect one another.
BUG? On AC power, I can select my in-car presets (they have the proper new names) but they are all set to Flat. When I get back in the car, the values are there again.
Edit: This sucks... the EQ settings do not transfer between car and home for both 2.00 and 3.00. This means I have to sit in the car and adjust these by hand... Still can't figure out why my EQ won't go below 50Hz.
Posted by: mcomb
Re: Success with Auto EQ! - 27/09/2004 22:39
Quote:
Given that Rob was the initiator in many cases for recent releases, I can't see much happening from now on, unforch
That'd be a real shame I had hoped v3 would at least turn into a reasonably solid beta. It appears that alpha 9 is DOA, 8 isn't publicly available, and 7 has plenty of issues of its own. Any of the remaining crew able to comment on the likelihood of at least getting a reasonably stable version 3 out before everyone that knows anything about it wanders off to do their own thing?
-Mike (morning the potential end of an era)
Posted by: tfabris
Re: Adjusting EQ Settings - 27/09/2004 22:40
Quote:
but I can't get the thing to select a frequencies below 50Hz...
Yeah, because they changed it so that you wouldn't manually induce the same clipping problem that Genixia just described.
On the plus side, the EQ details are saved the same way in version 2.0 as they are in version 3.0. You could go back to one of the older 2.0 betas before they limited the EQ, make your changes, then go back to whatever version you wanted to stick with. The EQ settings would then continue to work, as long as you never went in and re-edited that band.
So all of these bands from AutoEQ are not possible w. 2.00final...
Band 1: 25Hz, Q=1.33
Band 2: 40Hz, Q=1.33
Band 3: 63Hz, Q=1.33
There goes the idea of having a spare player to run AutoEQ on and then manually entering those values into a 2.00Final player.
Is having the in-car and at-home EQ's different by design as well? They keep the same names assigned to the preset number, so it seems odd.
Quote:
You could go back to one of the older 2.0 betas before they limited the EQ, make your changes, then go back to whatever version you wanted to stick with.
Do EQ settings survive player upgrades?
Posted by: newguy1
Re: Adjusting EQ Settings - 28/09/2004 00:27
Nothing to add except some questions.
It appears that a lot of settings(balance,bass,treble,auto volume,etc.)need to be set at their respective neutral position in order to prevent bad things from happening.(clicks,pops,blown speakers)
Would it be possible to boot the player in a "safe mode" with these controls at their neutral position?And then do the autoEQ.Or do it in Hijack?For instance.."if microphone 1 then set all controls to neutral"type of config.
Yes, it would be nice if AutoEQ would be smart enough to set these values at 0, but to be honest, the more I think about it, having the fader and balance controls adjusted so that the speakers have equal volume at the driver's position should do no harm and in fact should be preferred. I'm also beginning to thnk that locking the Left and Right channels in the EQ should be prefered since the acoustic energy coming from each speaker (and their effect on one another) has an effect on the perceived sound of your ears.
The crucial ones to turn off at the ones that actively effect the sound:
Player
Loudness
Stereo Seperation
Auto Volume Adjust
Crossfade
Pitchbend
Beep Level
as well as... Repeat
Random
HiJackBass
Treble
VolAdjust
Left/Right Time Alignment
Posted by: tfabris
Re: Adjusting EQ Settings - 28/09/2004 01:50
Quote:
Is having the in-car and at-home EQ's different by design as well?
Yes.
Quote:
This sucks... the EQ settings do not transfer between car and home for both 2.00 and 3.00. This means I have to sit in the car and adjust these by hand...
HiJack to the rescue! Force DC power mode to make the player perform as if it were in the car.
Answering my own questions here I see!
Quote:
Although the upgrade is not supposed to hurt your music files or player settings, it might be a good idea to note a few things on paper before upgrading to a new version: Your equalizer preset details, loudness setting, dimmer setting, and radio station presets. In most cases these will not be harmed, but it doesn't hurt to be safe.
Let's hope they are saved.
Posted by: schofiel
Re: Adjusting EQ Settings - 29/09/2004 16:04
It's not a bug, the house/car EQ presets are completely independent. Why would you want to use an EQ preset generated in one limited listening environment (in the car) in another completely different one?
Clicks and pops seemed to happen with high gain.
If you cannot select below 50 Hz then it is likely that the interactions between the various wavebands (Q and fc) means that the "envelope" generated by each band's output filter interacting with their adjacent neighbours means that there is no need for 50Hz band compensation.
However, it could also be that if you have a band on the equaliser displayed with an fc of 50 Hz, and the UI prevents you from accessing it to manipulate it, then it's a BUG.
Posted by: tfabris
Re: Adjusting EQ Settings - 29/09/2004 16:06
The 50hz thing was a change they made just before 2.0 final. After 2.0 final, you can't edit a band center to any value lower than 50hz.
Quote:
I t's not a bug, the house/car EQ presets are completely independent. Why would you want to use an EQ preset generated in one limited listening environment (in the car) in another completely different one?
It just seems that with as many presets we can have, you'd be able to view all of them at once. I guess what threw me off was that I had renamed Preset 2 as "AutoEQ1" and it was still called "AutoEQ1" while in the home. Anyway, it's not a big deal.
Posted by: Roger
Re: Adjusting EQ Settings - 29/09/2004 20:59
Quote:
and it was still called "AutoEQ1" while in the home. Anyway, it's not a big deal.
Feature request, then: the screen should display (home) or (car) after the name.
Or the EQ presets should be stored so that you can have one preset chosen for the car, and another, differently named, preset chosen for the home.
As opposed to the current way, where the home/car presets are different sides of the same coin, as it were.
Posted by: tfabris
Re: Adjusting EQ Settings - 29/09/2004 21:14
Quote:
the screen should display (home) or (car) after the name
And this is useful, how?
If the player is on, and you're in the house, it's home. If the player is on, and you're in the car, it's car. Why do you need to waste screen space to tell you where you're sitting?
Posted by: andym
Re: Adjusting EQ Settings - 29/09/2004 21:20
Well, I had partial repeated sucess last night, the really important thing seemed to be the volume, I had done previous autoeqs at a comfortable listening volume, this seems to be too much, either that or my idea of comfortable listening volume is too loud. Anyway, I turned it down and tried it and managed three or four reasonable runs, a few minor clicks and pops but nothing too bad.
I'll run it again when I get round to replacing my knackered HF driver. Should be some interesting results, the curve I got certainly sounds good, but my imaging is currently way off track.
Posted by: schofiel
Re: Adjusting EQ Settings - 29/09/2004 22:09
Good man, glad to hear you got it going. Mine also went nuts with high gain. Another success to chalk up!
Posted by: Daria
Re: Adjusting EQ Settings - 30/09/2004 00:44
Hm. scratchlib was going to know how to dump and load eq settings. Another project I should finish.
Please, please!
Posted by: Daria
Re: Adjusting EQ Settings - 30/09/2004 00:48
I even looked at it in Cincy, because we AutoEQ'd my car with genixia's player... I'll try to get to it soon.
I've been reading up on this (or trying to) and I keep coming across explanations of Parametric EQs where the Q represents an exact range of frequencies rather than a general shape of a curve. One site even had an interactive Flash thingy where you could play with the gains, center frequency and Q value and the results would be shown in real time on a graph. No matter how high I boosted the gain, the beginning and ending frequencies were always the same. I've been trying for 30 minutes to find that link and I can't ... it was for a main stream car audio manufacturer that was demonstrating this feature on their mono-sub amp.
Posted by: mtempsch
Re: Experiences with Auto EQ - 11/10/2004 05:48
Were they perhaps showing the frequencies manifesting the -3dB points relative to the centre frequency / max boost point? Those frequencies are fixed (as the definitions of Q I've seen all have been
Q = Fc / (Fh - Fl)
ie center frequency divided by high minus low border (-3dB) frequency). But from your description it sounds like they (at least intended to) showed a curve for the total frequency response... If you ignore the -3dB definition of the Fh and Fl, you would get the behaviour of the graph that you describe...
But the real affected frequency range (if boost <> 3dB) - compared to the "normal" level - is smaller or larger, depending on boost. At least from what I learned in school and what I've ever seen elsewhere too... Example:
this page, from a site I've found to be quite good. Not sure what happens when you go to low centre frequencies and also low Q though...
Quote:
Q is defined as Fc/Fh-Fl. Fh and Fl are defined as -3dB points. As soon as you boost beyone +3dB you're boosting outside of that range.
I know you didn't come up with this definition of parametric EQ, but this image seems to support the view that increasing gain does not increase the range of frequencies being amplified.
Image is from here .
Posted by: wfaulk
Re: Experiences with Auto EQ - 24/10/2004 18:53
That device also doesn't seem to have a Q adjustment, so they may have just elided that sort of info.
Posted by: wfaulk
Re: Experiences with Auto EQ - 24/10/2004 21:19
FWIW, Wikipedia defines
Q. It supports the 3dB thing and specifically calls out another bandwidth theory about it as incorrect.
Well, the evidence is stacking up against the cute Flash animation I saw that was probably designed by some graphics dude who doesn't even own a car, muchless a car stereo.
Assuming that's the case... where do we go from here? If applying large negative or possitive gains on any band will result in those bands overlapping, we should try to apply moderate gain (both possitive and negative) centering around the 0dB point. Yet, this inevidably causes us to apply possitive gain to our EQ which in turn, can result in clipping of the digital signal. What are we to do?
The only solution I can think of from the top of my head is to set your input gain (on the amp) with your Volume set to -10dB. Then, any adjustments made to the EQ, even if you add upto 10dB to any band, will not clip the signal before it is sent to the proc-amp. Am I getting this right?
That solution seems like it "would work" but we won't be getting the best signal to noise ratio (yet I doubt we'd notice). My main problem with it is that we'd have to remember that -10dB would be the highest we could set the volume without clipping. That's just ugly. Yet, if the input gain was properly set, I suppose we'd never have to raise the volume past -10dB without the music being too loud anyway...
Posted by: wfaulk
Re: Experiences with Auto EQ - 24/10/2004 22:13
Someone should design an app where you can plug in your measured results and have it graph them and then either provide you with an EQ where you could see the results as you twiddle with them or have it suggest settings. Of course, this is more graphics programming, more analog signal understanding, and more mathematics knowledge than I have.
Agreed. We might be getting worked up about nothing here. Depending on the Q setting, these other frequencies might not even be effected. Maybe running the 1/3 octave tests a few times would show if there were any peaks generated by excessive +/- gain.
We still haven't decided on which 8 frequencies to use if we want to use Treble/Bass adjustments. Could we use the EQ tutorial to get a "flat" response then bump up bands 2 and 9 for Bass/Treble? It's sad we can't access the DSP's built in Treble/Bass.
I finally found that link...
JL Audio
Posted by: mtempsch
Re: Experiences with Auto EQ - 25/10/2004 07:02
And looking at the text regarding Q, they're contradicting what's shown in the graph and agreeing with what's been said here:
Quote:
"As the level of boost increases, you are not just boosting frequencies within the defined bandwidth. There will still be considerate boost outside the defined bandwidth, especially with lower "Q" settings."
But then they also add a sentence that says that the Q value doesn't remain constant while you fiddle with the boost knob on their amps - so the graph still makes sense for their implementation of the circuitry:
Quote:
"Please note that the "Q" setting marked on the amplifier is referenced to maximum boost. "Q" will drop in value as boost" [text is cut off there, I assume it should say "level is decreased." or something similar]
Ah... now that's making sense..
Posted by: peter
Re: Experiences with Auto EQ - 25/10/2004 10:46
Quote:
FWIW, Wikipedia defines Q
Note that the "cutoff frequency" definition linked from there has a typo: -3dB is 10^-0.3 or 50.1%, not 70.1%.
IANAJ(*) but as I understand it, the "-3dB" refers to 50.1% of the size of the effect at the centre frequency, not 50.1% of the output response. So if your gain on a particular EQ channel is +2dB of the output response, the "-3dB points" of that channel are where the effect on the output response is 50.1%, or half that: in other words, the frequencies where the effect on the output response is +1dB.
This means that any adjustment has some effect beyond the -3dB points. Indeed, any adjustment theoretically affects the entire audio spectrum, though the effects become negligible at any great frequency distance from the centre. Quite how rapidly they fall off (for instance, where the -6dB points are) depends on the exact shape of the filter.
As a concrete example, if you have an EQ band centred on 100Hz, with gain of 4dB and Q of two octaves, the boost would be +4dB at 100Hz, +2dB at 50Hz, and also +2dB at 200Hz. Frequencies just below 50Hz would be boosted by just less than 2dB, as would frequencies just above 200Hz.
Interpreting the "-3dB points" to mean "the places where 3db less difference is made to the output response" would make Q meaningless for EQ bands whose centre gain was smaller than 3dB.
Peter
(*) I Am Not A John, or, put differently, I'm not one of Empeg's two EQ gurus.
Posted by: wfaulk
Re: Experiences with Auto EQ - 25/10/2004 12:09
Quote:
Note that the "cutoff frequency" definition linked from there has a typo
So fix it!
Posted by: peter
Re: Experiences with Auto EQ - 25/10/2004 12:22
Quote:
So fix it!
Oh, is that how it works? Right-ho then.
Peter
Posted by: genixia
Re: Experiences with Auto EQ - 25/10/2004 12:32
Yeah, fix it so that it says the correct 70.7% please.
Posted by: peter
Re: Experiences with Auto EQ - 25/10/2004 12:37
Quote:
Yeah, fix it so that it says the correct 70.7% please.
10dB corresponds to multiplying by 10. So -10dB corresponds to multiplying by 10^-1 or 0.1. So -3dB corresponds to multiplying by 10^-0.3 or about 50.1%.
Peter
Posted by: genixia
Re: Experiences with Auto EQ - 25/10/2004 13:36
No...
Quote:
Decibels (dB). A logarithmic representation of amplitude ratio, defined as 20 times the base ten logarithm of the ratio of the measured amplitude to a reference.
dB = 20 log (Vx/Vref). In this instance, Vref = 1, dB = -3
-3/20 = log Vx
Vx= 10^(-0.15) = 0.70795
Bizarrely, I think that I've often seen that rounded to 70.7%, even though it should be 70.8%. Maybe it's because it's so close to root 2.
For reference, this is when talking about voltage or current. When talking about power the equation changes and becomes 10 log (Vx/Vref) as you expected.
Let's say that you have an amplifier driving a speaker. The power from the speaker is given as V^2/R. So let's look at our power at that -3dB point relative to the peak;
Now at this -3dB voltage point, the power generated in the speaker is (0.708^2)/R = 0.501/R, ie half that generated at the peak. That is why the -3dB voltage point is also known as the half power point.
If we now look at the power equation:
dB(p) = 10 log ( Px / Pref )
dB(p) = 10 log ( 0.501 )
dB(p) = -3
So the -3dB point is -3dB regardless of whether we are talking about voltage or power, even though one is a function of the other squared. It also holds for current equations too, dB(I) = 20 log (Ix/Iref), as Power = I^2R.
Basically it all boils down to log a^b = b log a. The equations are different to give the same answer despite the square relationship between voltage/current and power.
Posted by: peter
Re: Experiences with Auto EQ - 25/10/2004 14:10
Oh, OK. So the page should say something like "-3dB is 50.1% of 100% power, 70.8% of 100% amplitude"? That makes sense.
The bandwidth in octaves quoted for the car-player hardware EQ -- assuming it's the same as the
Karma software EQ -- is between the points where the gain in dB is half that at centre. So the example I gave upthread is still right AFAICT.
Peter
All of this is sorta over my head... but how does it all translate to getting proper EQ settings?
Posted by: woops
Re: Experiences with Auto EQ - 25/10/2004 23:12
i did autoeq using a computer mic (omnidirectional supposedly) and i must say the sound is SO MUCH better (i turned down the first two (bass) and the last (treble) bands just slightly) Thanks, SE_Sport_Driver, for the gift of making me aware, this really does make the empeg so sweet.
As you can see, I havea lot of people to thank too!
The funny thing is that I started the page because my buddy moved away to Colorado recently. A few days before he left, we finally installed his empeg into his WRX. We never got a chance to tweak the sound on it.... next thing I know, I'm making a whole tutorial. I thought 20 or so people would be into it, but I'm surprised at all the views that thread has gotten!
As long as people are interested, I'll keep working on it.
Posted by: Jemmi
Re: Experiences with Auto EQ - 05/03/2005 17:23
Thanks so much for these instructions... I finally got around to doing this today. I'm amazed at the overall clarity even at high volumes. I added a 9db loudness boost and that is all and even music that my system sometimes had issues with (folk, bluegrass, some country - sparse instrumentation and bass mixed high) sounded perfect even when loud... and it was all so clear. I love it!
Posted by: mcomb
Re: Experiences with Auto EQ - 13/03/2006 18:25
Is anyone able to recommend a mic for this that is readily available in the US and matches the specs needed? I see that Brad linked a Radio Shack module that was said to work, but the link no longer works and he didn't give a part number. Also, can someone provide a link for the needed sound files?
Thanks,
-Mike
Posted by: matthew_k
Re: Experiences with Auto EQ - 13/03/2006 19:06
Model 33-3013 Hands-Free Tie-Clip Omnidirectional ElectretThe model number is "33-3013" and the cord is 3.3333 feet long. coincidence??
A write up may be coming on this soon... I'm using my 10gb player with 3.0alpha on it WAY more than my 160gb empeg these days so I'm itching to try it.
Basically though, turn off all sound modifications, (bass, eq, volume adjustments, etc, etc) and take the player out of shuffle. Clip the microphone to yourself, as close to your ears as possible. There is no point in making the EQ sound good for someone sitting in the dead middle of the car unless you plan on sitting there!
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 00:12
Thanks guys! I'll probably swing by Radio Shack on the way home and see if I can get this going.
-Mike
Posted by: mlord
Re: Experiences with Auto EQ - 14/03/2006 00:41
Quote:
All of this is sorta over my head... but how does it all translate to getting proper EQ settings?
All I can say is, Good Thing(tm) we had another (ex)Brit around to correct the (current)Brit! Us North Americans had no chance on this one.
Cheers
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 04:58
Well, I tried to get this to work, but so far all I'm getting is silence. I believe I followed the directions exactly. I can play the noise files by hand, but as soon as I select AutoEQ it just sits there. No noise is played and it doesn't appear to be doing anything. The only thing I can think of is that I loaded the files with jEmplode (no windows box handy), is there any reason why that would matter? Any other suggestions?
Thanks,
-Mike
Posted by: schofiel
Re: Experiences with Auto EQ - 14/03/2006 09:29
You have to select the files as a playlist before starting. Also, I found that the microphone connector was "jammed shut" - I couldn't insert the jack all the way in and I was scared of pushing it any harder without breaking. It did however suddenly "seat" properly and then started working. So I would suggest you:
- check the continuity of your microphone is OK
- unscrew the microphone socket on the harness and check the contacts are free to move
- that the contacts have continuity to the contacts on the harness connector in the sled.
Quote:
Here's the story:
- downloaded the Auto EQ test audio files to a new playlist, and made sure they were ordered by using ALT-drag to set them sequentially in correct playback order
- synched
- went to the car and plugged in the mic, making sure it clicked home properly against the face of the socket on the harness (IMPORTANT!)
- positioned the mic next to my head over my shoulder
- turned on the ignition, turned off the ventilation and other noisy bits
- plugged in Erik the Empeg and waited to boot
- went into HiJack, turned off Bass and Treble adjust
- turned off Auto Level Adjust
- dropped out of HiJack
- using the rotary, turned off beeps, cross fade, loudness, and centred the fader and balance
- in the main menu, chose Playback and turned off Repeat, Shuffle, etc.
- went to the playlist with the auto EQ test files and selected them for play with the arrow (Play All) then hit pause.
- went to the equaliser
- selected an unused equaliser preset (#16 in my case)
- selected locks to be independent
- selected channels to be 2 (Stereo) (IMPORTANT!)
- set the volume to -30 dB
- held our breaths, and....
- selected Auto EQ and away we went!!!! (Rumble Rumble Whirr Whirr Wheee Wheee Hisss Hisss)
This is just part of the first post in this thread... I'd skim that post and the first few pages for anything that may have been missed (if any) when he first wrote that.
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 14:59
Quote:
You have to select the files as a playlist before starting.
I did this.
Quote:
- check the continuity of your microphone is OK
- unscrew the microphone socket on the harness and check the contacts are free to move
- that the contacts have continuity to the contacts on the harness connector in the sled.
I did plug and unplug the microphone a couple times yesterday and it seemed to seat fine. Before I take my dash apart again to get to the mic jack doesn't the fact that microphone shows up as an audio source on the empeg imply that it is installed properly? Also, the empeg isn't even playing the tracks, why would this have anything to do with the mic?
Thanks for your help,
-Mike
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 15:03
Quote:
This is just part of the first post in this thread... I'd skim that post and the first few pages for anything that may have been missed (if any) when he first wrote that.
I have read the entire thread. The only things that appears to have been mentioned later on are:
1. The empeg may be able to find the files on it's own without manually selecting the playlist. I tried this as well, didn't make any difference.
2. There are some additional audio adjustments that need to be turned off that Rob didn't mention.
It is certainly possible that my Rat Shack mic is dead, but wouldn't the empeg still play the files even without the mic?
-Mike
Posted by: schofiel
Re: Experiences with Auto EQ - 14/03/2006 17:34
Well, yes and no. You DON'T select the Mic as a source. You select the player as the source, and then select the test tracks as a playlist, in the order they are to be played by the AEQ. It's obvious from the names - low to high frequency. You then kick off Auto EQ and it will play them back.
As a word of caution, make SURE your gain is set to between -25 and -15 dBA on the volume control otherwise you risk both your amp & speakers along with your hearing. And no, I'm not joking.
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 19:10
Quote:
Well, yes and no. You DON'T select the Mic as a source.
I know, I just meant that it is showing up under the source menu on the empeg.
Quote:
You select the player as the source, and then select the test tracks as a playlist, in the order they are to be played by the AEQ. It's obvious from the names - low to high frequency. You then kick off Auto EQ and it will play them back.
I've done this and they don't start playing. The empeg just sits there, with or without the mic connected. Can someone else load these tracks on their player and see what happens if you select AutoEQ without a mic connected and again with? If the tracks don't play when the mic is disconnected, but do when it is connected you'll help me narrow this down a lot.
-Mike
Posted by: schofiel
Re: Experiences with Auto EQ - 14/03/2006 19:24
No, look - you have to start Auto EQ off with this as the selected playlist, paused.
Can I gently suggest that you go back to the first posting of the thread, and read through the instructions again?
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 19:44
Quote:
No, look - you have to start Auto EQ off with this as the selected playlist, paused.
I think we are misunderstanding each other here. I've done exactly this, repeatedly. I appreciate the suggestions, but I swear the problem is not that I don't have the appropriate playlist selected and paused.
Edit: Which is why I'm trying to get someone to help troubleshoot if a bad mic connection could cause this.
-Mike
Posted by: mcomb
Re: Experiences with Auto EQ - 14/03/2006 21:32
OK, I've got it figured out. The problem seems to have come from loading the files with jEmplode. I reloaded them with Emplode and the empeg is now playing them fine. There must be something different with the tags they are creating that is keeping the jEmplode files from getting recognized. Thanks for the suggestions Rob and Brad.
-Mike