Reference Tones?

I know this is probably silly but when I was setting up my HTS (I am not an audiophile but i play one at home) I got a CD that helped me calibrate the video (color, contrast, etc) and my receiver (Marantz SR-19) had reference tones that I used with a SPL meter to make sure where I was sitting had the same decibels from each speaker (maybe that is too simplified but that is how I saw it).

Is there a way to do this with the empeg/amp combo? So that from where I sit, each speaker is hitting my ears at/about the same time? Or something to help me setup the EQ....To be honest, I am partially deaf in my left ear (been that way since i was a kind but my dad thought i was just ignoring him!) so it may not be a good way to do it...

Just thinking as I wait...I-Day (install day) is 2 days away (Oct 14).

In reply to:

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Is there a way to do this with the empeg/amp combo? So that from where I sit, each speaker is hitting my ears at/about the same time? Or something to help me setup the EQ....To be honest, I am partially deaf in my left ear (been that way since i was a kind but my dad thought i was just ignoring him!) so it may not be a good way to do it...

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What I do is basically is similar to what many people who compete due for tuning their systems. Various test discs are available that are specifically designed for Car Audio setup -- the one I use is the AutoSound series (I think Crutchfield still sells them, that is where i picked 'em up from). There are 4 CD's total, and CD 2 specifically deals with imaging. Each one has notes on the tracks and how to use 'em to your advantage.
To use them with the empeg, you would have to convert them at the highest quality setting for .Mp3's, or hook a CD player up to the AUX input.
Hope this helps ya out!

Greetings!

If these are just pure tones, you can use a package like Cool Edit or Sound Forge to generate a wave file of a specific frequency. You can even generate mixed tones if you like.


Paul G.
Q# 15189
SN# 090000587 (40GB Green)

If these are just pure tones, you can use a package like Cool Edit or Sound Forge to generate a wave file of a specific frequency. You can even generate mixed tones if you like.

Having done this myself, I can attest that this does work quite well. I even posted the MP3 files at one point (although I think I took them down recently). I also discovered that you can't MP3-compress an 18khz sine wave and expect it to sound proper...

___________
Tony Fabris

I saw some demo code on the developer site to make the DSP beep, couldn't this be adapted to generate certain frequencies ?

Frank van Gestel

Anyone have or know where I can find pink noise, white noise, etc.. in MP3 format?

-steve

If you buy a copy of the IASCA competition disk, there are a number of test tracks doing various things, including an uncorrelated Pink noise track.

One of the few remaining Mk1 owners... #00015

Anyone have or know where I can find pink noise, white noise, etc.. in MP3 format?

Is it safe to use MP3-encoded white or pink noise as a reference? I'd be concerned that the compression would eliminate some of the frequency content as inaudible, when really you want it all there regardless so that you can calibrate to it. It seems better to stick with uncompressed files instead.

Michael Grant
12GB Green
080000266

Ah ha....but therein lies the rub no? If the compression on the pink noise would effect the spectrum....wouldn't it affect music tracks the same way? Isn't it all relative? Maybe not with MP3 compression though...the EQ effects of compression might totally depend on the content, the algorithm used, the bitrate, etc...

But my theory is this.... If, hypothetically, 2000hz was boosted in MP3's....and therefore the pink noise was showing up un-even......I would set the EQ to compensate...and that would be a good thing...because music would have the same 2k spike....and my new EQ settings would correct it....

Its probably not this exact...but its better than nothing and I don't have anything better.

By the way....are there any threads addressing the subject of ideal EQ curves. This EQ is EXTREMELY flexible with the parametric (full parametric I might add...with both frequency and Q adjustable. Its easy to get out of control with it....

If the compression on the pink noise would effect the spectrum....wouldn't it affect music tracks the same way?

Of course it would! But the difference is that MP3 is designed to ensure (as best it can) that those differences are inaudible for the music being played. Encode a different song, and different frequencies will be lost.

If you're measuring the frequency response of your sound system, though, you need all of the frequency content there, audible or not.

But my theory is this.... If, hypothetically, 2000hz was boosted in MP3's....and therefore the pink noise was showing up un-even......I would set the EQ to compensate...and that would be a good thing...because music would have the same 2k spike....and my new EQ settings would correct it....

No, that is definitely not the case. The frequencies altered by MP3 encoding, and the manner in which they are altered, are entirely dependent on the context---i.e., on the song being encoded. A 2000Hz tone might be left alone in one song, and completely removed in another.

Michael Grant
12GB Green
080000266