I've been disturbed for years by the supposition that: I can get the highest quality audio components in existance, but if the source sucks, it's all worthless. Is this unfounded? And how does it translate to "high quality" in-car mp3 audio?

Do you guys with perfect sound systems (tanstaafl, etc) get high quality out of your empeg?

Is it just a matter of using high bitrates and great encoders?

Most importantly, what if the underlying CD is low-quality for ANY number of reasons? (analog recording, bad mix-down, clipping, bad compression, just too darn quiet all around, etc) I honestly think that a bunch of my major-label commercial CDs just sound sub-par.

Bottom line is, before I go researching high quality in car audio and spending plenty of money to get a great system, will it all be undermined by me playing mp3 through it or undermined by poorly done CDs?
And since most of my MP3s are 128 and 160, I guess I have to give up my dreams of good in-car audio (since I don't want to re-rip again), but what kind of equipment would you recommend to make it at least sound good?

Thanks.

IMHO:

1. You're in a car. The car is usually MOVING, or you wouldn't be in it. Engine noise, tire noise, wind noise, traffic noise, etc, etc, are many orders of magnitude more noticable than CD vs mp3 at *any* bitrate, but especially at 256kb CBR, or something like that. I've never been able to understand this discussion and I usually stay out of it. A car is NOT an ideal listening environment in the best situation. People do the same thing with home stereos, too, spending thousands of dollars to get a tiny fraction of the difference that making easy changes to their listening room would make.

I, respectfully, submit that this all has *nothing* to do with sound quality...

2. Analog recording doesn't mean lower quality than digital recording. Some recordings suck. Some are even released out of phase (I have no idea how this can happen). I agree that many CDs sound bad. If the source sucks, it will still suck as an MP3, obviously.

I really doubt that, even on a many-thousand-dollar car audio system, many people could reliably discriminate between 256kb/sec mp3 and uncompressed files played from the same source. I'm sure some could. I'd bet my next paycheck that they couldn't at 70mph.

Jim

Yes, you can get high quality out of the empeg. You can't expect absolutely bit-for-bit perfect soundstaging from a data-compressed MP3, but if you use a high bitrate with a good encoder then you get darn close. On very high quality equipment, you personally would not be able to tell the difference between MP3 and the original uncompressed wave data. You'll need to re-rip at something higher than 128/160 though.

There is nothing wrong with spending money on high quality speakers and amplifiers for a car stereo, regardless of whether you're playing original CDs or MP3s. Low quality car speakers and amplifiers are genuinely crappy sounding no matter what you put through them, and high quality components will sound better than low quality ones no matter what you put through them.

Your only real question should be... How much do I like to listen to music in my car, and how much time to I intend to spend doing it?

For me, personally, my car is where I spend the most time not only listening to music, but paying attention to the music instead of just having it drone in the background. So it's important to me to have high quality components in the car.

Firefox,
I had the same concerns as you about audio quality. I just completed a test of MP3 bitrates and uncompressed Wav files on my primary home music system. Although I probably haven't spent as much on it as many others, I have nice full range tower speakers(Stereophile B), Krell premap, and nice sounding Modwright modded digital sources.

I came to the conclusion that 256CBR was the way to go for me. Although I could tell the difference between 160kbs and 256kbs, I could not easily tell the difference between 256, 320 and uncompressed wav.
YMMV.

Thanks for the feedback all. I guess I'll have to re-re-rip to 256 CBR or so because my 3 year old AudioCatalyst 160 and l3enc 128 rips are just not cutting it.

But more than that, the source sound can sometimes seem lacking. I honestly don't think I've EVER experienced audio which is engrossing, surrounding, and "present"; with the only exception of a single high quality radio station. When, on my home amplifier, I switched the radio from Mono to Stereo, I felt immediately engulfed by the sound. Everything else in my world seems like a left mono and a right mono; just two speakers pushing sound at me from one direction. Hardly anything I have really wraps around my ears and surrounds me.

Maybe that's because I listen with headphones at home nearly 100% of the time (Lafayette F990's from back in the day). But in the car, it's the same. I hear noise coming from my feet, and that's it. But both in home and in car, I want more. I feel like I'm really doing something wrong, and I really want to get more out of the music.

So, bitrates aside, can car audio (and via headphones at home) really deliver engrossing, surrounding sound? What's all the talk about "sound stages" and "phasing" and "component speakers"? Will any of that enliven the 90% of my collection which sounds dull and lifeless?

And on a side note, for some reason the only MP3s (and, thus, their respective CDs) I have which sound good are the ones that sound LOUD. My REM collection sounds flat and weak because they are quiet; even if I turn up the volume. But my, say, Rush "Test for Echo" or Incubus "Morning View" sound really engrossing because they are loud. I did read the FAQ entries on audio compression, but am I missing something? Should I just turn the volume knob up when REM comes on and turn it down for Incubus in order to maintain the same level of audio presence? Or is the very core source of the REM CD's just plain bad recording?

Thanks again; this issue has been troubling me for about as long as I've had ears.

In reply to:

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... this issue has been troubling me for about as long as I've had ears.

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Perhaps that is the problem. According to your avatar--your ears are missing! :-)
- Tim

Yeah, I'd have to agree - nothing sounds like listening on headphones. I remember when I got my first set of speakers - I'd bought the receiver and been using headphones in my room for a few months before I could afford speakers. I remember being so disappointed that they just did not sound as good as the headphones unless I sat square between them. They were decent speakers too - AR 410's, circa 1985.

A few years ago I decided to get a good set of headphones, having been without them for about 10 years since my last set wore out. I was just floored. While I'm sure there are setups out there that rival good headphones, I know I haven't heard them.

-Zeke

So, bitrates aside, can car audio (and via headphones at home) really deliver engrossing, surrounding sound?

Yes, with well-produced and well-mastered music, and good playback equipment. It doesn't matter where you're sitting, what matters is the equipment and the material.

For me, yes.. MP3s can do it.

Nothing is going to beat the sound quality you will get from a great set of headphones, in my humble opinion. But headphones are not practical in a car. So headphones aside..

I do not consider myself the audiophile that most on this board are. I have a quality amp for my empeg, but still use the factory speakers, much to many of my fellow empeg heads amazement. The quality of music is fine for me.

I dont analize the music when I am driving, I simply enjoy it. A lot of my songs are ripped at 128, a lot at 160, and even 256. I use a standard ripper I downloaded for free. I guess my point is I dont expect home stereo or even headphone quality while in my car, and I am not disappointed if something does not sound as well as it would if it were performed live in front of me. The quality is good enough for me, good enough for me to shell out the bucks to purchase this amazine product because of its features.

You and I look at the whole experience from different angles. Neither one of us is wrong, just different.

Trying to look at it from your point of view, I would suggest investing in quality audio equipment for the car.. but at the same time realize that there is going to be a plateau where sooner or later the sound quality is pretty much maxed out.. and that spending more money will only yield a small gain. Find that area where you are comfortable, and then start enjoying the experience instead of trying to squeeze that last little ounce of improvement out of your speakers.

In reply to:

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And on a side note, for some reason the only MP3s (and, thus, their respective CDs) I have which sound good are the ones that sound LOUD. My REM collection sounds flat and weak because they are quiet; even if I turn up the volume. But my, say, Rush "Test for Echo" or Incubus "Morning View" sound really engrossing because they are loud. I did read the FAQ entries on audio compression, but am I missing something? Should I just turn the volume knob up when REM comes on and turn it down for Incubus in order to maintain the same level of audio presence? Or is the very core source of the REM CD's just plain bad recording?

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If you like "loud" recordings, run your REM albums through some hard limiting software. Experiment with the settings. You will probably want to get the loudest portions to average -10 - -12 dB if you want them to match the "volume" of those loud recordings you mentioned.

Stu

IMHO, car noise pollution tends to exist in the lower frequency range. I am able to clearly hear high frequencies at both 0mph and 80mph+.

I think this effect emphasizes high freq and makes mp3 distortion sound _worse_! Mp3's have the hardest time with high frequencies - they are trying to encode high bandwidth information with relatively low bitrates. Although in-car noise pollution may mask lower frequencies, I can travel 100mph and still cringe at the flanging and other distortion present in a bad mp3.

While the car is a very bad listening environment, I have been very happy improving the audio quality of my system, as well as encoding mp3's at higher bitrates (320kbps). I've even gone as far as running S/PDIF digital to the trunk, where I have a studio-quality DAC modified to run off 12 volts.

Home-audiophile quality? No. I do agree there is no point in spending thousands on a car system. However, with my schedule (and my commute), I really only get to listen to music in the car. The hundreds I spent on DAC/amp/speakers were worth every penny!

Thanks for the insight, all. Yeah, headphones are hard to match, but the stereo field generated by "stereo FM broadcast" has even engrossed me MORE than headphones (with the exception of Rush's "Twilight Zone" with it's panning whisper track snuck deep behind the instruments and vocals). And I couldn't agree more that car envorinment hurts the bass, which brings out the washy trebble of MP3.

So, I guess my quandry is more about the quality of the stereo field... the presence of the sound... than it is about bitrates and loud volume. Here's text from a manual for a 3D sound generation device from 1989 (which a knowledgable audio guy at work photocopied for me):

"A good test for evaluating a quality audio system involves closing one's eyes and listening for the loudspeaker locations. If one can readily point to the drivers, the system is not an accurate audio reproducer."

So, on the question of "how much to spend on a car audio system", is it possible to get such a truly engrossing sound stage that you can't pinpoint the location of the speakers? If so, I'm willing to pay to have that.

So, on the question of "how much to spend on a car audio system", is it possible to get such a truly engrossing sound stage that you can't pinpoint the location of the speakers?

In a word... Yes.

In IASCA competitions, everybody has to play and be judged on the official IASCA CD. Part of the process involves the judges using a diagram of where the individual instruments were located when the tracks were recorded. You will lose points if the placement of the sound from your system (known as imaging) does not match the diagram.

One of the tracks is a series of seven drumbeats that march left to right across the front sound stage. Ideally you will get a placement that looks like

#......#......#......#......#......#......#

Most systems will sound like

...#..#..#.................#..#..#..#.....

or a mirror image depending on whether you are in the passenger or the drivers seat.

[bragging]
The sound stage in my car sounds like it is evenly spread from left to right about halfway up my windshield -- including the subwoofers.
[/bragging]

It took a lot of money and a lot of tuning to get there.

tanstaafl.

Tanstaafl, congratulations for your install. Do you have any picture somehwhere? If you do and everybodny knows but me , I'm sorry, but recently I've not been able to follow this blard as I'd like...

Do you have any picture somehwhere?


I have lots of pictures, but they are not posted anywhere. I don't have a website or anything (I'm convinced this internet business is just a passing fad and making a website would just be a waste of time) and in any case the pictures I do have are now obsolete as I have completely re-done the system. I am now running a separate class-T amplifier for each one of my five channel pairs, with remote gain controls built into the center armrest for each amplifier, along with a 30-band (1/3 octave) stereo equalizer.

Right now it sounds really terrible, embarassingly so, I have picked up an alternator whine that I can hear quite well with the stereo playing loud enough to listen to at 70 MPH. Gotta be a ground loop -- but with 5 amplifiers, two head units, a Sony switch, an equalizer, and four passive crossovers between my battery and my speakers, it's not gonna be easy to find.

tanstaafl.

With all the ground loop problems, I'm surprised the car audio industry hasn't standardized on TOSlink interfaces. They're present on $40 CD players, so they can't be that expensive.

Regarding imaging... I once had a passenger tell me my subwoofer must not be that great because the bass wasn't coming from the back!! People don't get it.

tanstaafl, what are the keys to good imaging?

Regarding imaging... I once had a passenger tell me my subwoofer must not be that great because the bass wasn't coming from the back!!

ROFL. Some friends asked me similar questions when I began designing a fiberglass-made small sealed box to accomodate two JL Audio 6W0s under my Mini's dash panel. "Aren't subs supposed to be huge boxes you put in the trunk"?

I have nice full range tower speakers(Stereophile B)

Are those Genesis Stereophile towers? Oh, those are impossible to get here in my country (along with almost any high-end music equipment, actually).

> tanstaafl, what are the keys to good imaging?

keys to the bank vault would be my guess

tanstaafl, what are the keys to good imaging?



keys to the bank vault would be my guess

Actually... it's like real estate: Location, Location, Location.

When we installed my system, we removed the windshield to gain access to the top of the dash, and cut holes and installed some very good speakers (Diamond Audio Hex series 4.5"/1" separates) way up in the very corners, right next to the glass. We then cut a hole right in the center of the dash, and installed a 4"/1" coaxial speaker (with titanium dome tweeter) as a dedicated center channel. All six of these speakers (if you count the coaxial center channel as two speakers) are aimed right up into the windshield, where the sound is then reflected back to the passengers.

The door speakers (front doors only) are located very high up in the doors -- a matter of a couple of inches below where the glass starts. These are also good speakers -- 6.5" Diamond Audio Hex series again. This eliminates the problem I see with many installations where the mid range speakers are located in kick panels down by the feet, dragging the whole sound stage down to knee level.

My subwoofers (two Diamond Audio 10") are located where the spare tire used to be -- clear in the farthest rear corner on the left side of the car. They are molded right into the side of the car, and the spare tire cover goes over them so that there is no evidence that the speakers are there when it is in place. The full size spare tire was replaced by a space saver spare which now resides in the under-floor storage compartment (station wagon, remember), and then the spare tire was covered by a 1/4" thick aluminum plate 31" on a side, hinged at the front. Mounted on top of this plate are the amplfiers, crossovers, equalizer, power blocks, amp turn-on relays, etc. Then the storage compartment door closes over all that, leaving a totally stealth installation with nothing other than the head units and the remote gain controls (built into the armrest) visible. There is about 1/4" clearance between the bottom of the amp rack (the aluminum sheet) and the spare tire, and about 1/4" clearance between the bottom of the "floor door" and the components on the rack. Remember that the amplifiers are Class T amps, far more power efficient than the normal class A/B amps, thus throwing off far less waste heat. It's a 1400 watt system and on a six hour road trip the components get noticeably warm, but not hot. I'd guess no more than 115 degrees F.

The subwoofers' imaging I cannot take credit for -- it is a freak of the acoustics of the Taurus wagon. For whatever reason, those subs sound like they are in front of me, even though they are about 7 feet back. I have no explanation.

Finally, there are the speakers in the stock location in the roof, clear in the back of the car. These are not DIamond Audio speakers, but Boston Acoustics. The stereo shop gave them to me for free because he had no use for them. Some kid brought his slammed Civic into the shop and told Dave (the stereo guy) to pull his old speakers out and replace them with Alpine, because Alpine was really hot sh*t. So, Dave pulled out about $300-$400 worth of high end Boston Acoustic speakers and put in probably about $150 worth of Alpine junk. The kid was happy. I was happy. Dave was happy.

Having the remote gain controls for each speaker pair lets me do two things: I can move the sound around to wherever I want it by adjusting the gains on the individual amplifiers; and I can change the character, the tonality of the sound the same way. All I have to do is bring up that titanium dome tweeter in the center channel a bit, and the sound gets noticeably brighter, at the expense of a narrowed sound stage. Want a bit more warmth and presence? Add a bit to the 6.5" door speakers and you're there, along with a wider stage. More ambience is available with the roof speakers, the subwoofers will make you think someone's kicking the back of your seat. I have a Crystal Method demo track I use that literally moves the car on its suspension. The two 10's are in a common enclosure, where acoustic coupling takes effect, giving me lower than normal frequencies for 10" at the expense of maximum decibels, which I don't care about at all -- the car isn't loud, it'll hit maybe 130 decibels max.

It takes months to tune a system like that. Oh, I could RTA it on a pink noise track -- but a perfectly flat pink noise curve, while impressive to the technopiles, doesn't sound all that good. One thing I've learned over the years tweaking stereos is that you can only tune it for about 20 minutes at a time. After that, anything you do to it makes it sound better -- lots better -- until the next morning you get back in the car with "fresh" ears and realize just how badly you screwed it up. I've gotten to where I don't tune by ear at all any more, at least not in the sense of turning knobs while I listen to it play. Instead, I live with it for a few days, decide that, yeah, I need some more mid-bass in the 800-1000 Hz area, and then (with the stereo off) adjust the appropriate control by the amount I guess will do what I want. Then, I listen for a few more days and repeat the process. Takes time and determination.

I do have sort of a picture I can place here. It is a .jpg of my signal path diagram, and on it there is a tiny picture of the amp rack before i changed over to the 5-amp system, so it doesn't look much like it any more, but will give you some small idea of the general layout. See attached.

Wow, looking at this post, you'd never guess that I enjoyed bragging about my stereo, would you?

tanstaafl.

Impressive. And to think I removed my PA4100 and left it in its case because of "not so good sounding"... guess what it needed was some better tweaking and specially better speakers. Indeed I had a system similar to yours as I had a PA4100 for mids and highs and a PA275 for the sub. A very very stupid installer managed to blow the 275's internal caps and that was indeed the beginning of the end of my first really important install. Sigh. Now I'm still working on details of my three-Genesis-amp system. Has anyone heard about the new "audiophile" speaker series? I'm considering a set of those for front stage...

I have a Crystal Method demo track I use that literally moves the car on its suspension.

The Uberzone mix of Busy Child?

Peter

Actually, I think he means the original version of Busy Child from Vegas. Now you've got me wondering where to get this uberzone mix.

the original version of Busy Child from Vegas

Right.

tanstaafl.

Now THAT'S the info I was jonesin' for. Thanks so much. And thanks everyone for all the info in this thread. I'm going to process it, do some research, and see what I can learn.

And after tonight, I've dispelled (most) all my disbelief that the empeg can do truely great audio. I listened to Maurice Ravel's Piano Concerto in G, followed by Gustav Mahler's Symphony No. 1 with my empeg set to -5db (since any lower and I could barely hear the quiet parts) and it really sounded great, even on my sub-par setup. So, with a few new speakers, maybe a new amp, and that custom fiberglass sub enclosure I've always wanted, I should be set. Thanks again.