Software options for Tuning - Page 13

durwood · 11-10-2006, 12:03 PM

Quote: Originally Posted by turbocad6

my first thoughts along these lines were that it will be processor intensive... my second thoughts were to use a dedicated machine for this, & then another as the actual carpc...

I mean the alpine is a dedicated box, so this could be too... a kvm could keep this managable through one screen... I don't know if I'm the only one who would consider multiple machines though... I have 2 motherboards going in my minivan right now, one for front & one for rear... adding a 3rd wouldn't be that intense for me....

I'd be afraid trying to run everything on one machine will cause issues, maybe a really fast dual core with a system that can take advantage of this, but I would rather do independant pentium m machines.....

so how crazy is running a dedicated machine for audio processing? would anyone else consider this?... imagine if it could run on linux... it could be kinda like the alpine in the end, BUT with everything we'd want... best audio quality with pc interface.... is this a consideration? I don't know enough about linux to do this, I guess a stripped down xp machine could do this well too.... maybe an xp embedded solution.....

Ya I was begining to think the same thing. It would be a total geek cool factor. I know for competing it would help me out because there is usally points for having an external processor. Having it all built into a headunit/computer just doesn't seem to count...BASTARDS! I look at it as an expense and space factor though. I liek that everythring I have takes up as little as space as possible and is hidden with still plenty of trunk room. Hmmm...

RedGTiVR6 · 11-10-2006, 12:18 PM

I'm not willing to consider multiple machines at this point. I simply don't have room for it.

Since I'm not concerned with ultimate sound quality while watching DVDs (which I don't do) and since I'm not concerned with audio in 5.1, I'm feeling that it won't be nearly as intense as the guys over on DIY are experiencing.

I'm also looking at running a micro-atx board with a Pentium D 3.4 GHz and 2 gigs of ram to do this.

Sure, powering it will be difficult, but there are ways around that now.

regarding linux - there were some guys int hat DIY thread that were talking about it, not sure if anyone followed through on it though.

turbocad6 · 11-10-2006, 12:35 PM

I guess this is true too... with a simple stereo setup there will be only 5-6 x-over points... I'm assuming the xovers will be the most intense part of processing...

RedGTiVR6 · 11-11-2006, 09:08 AM

all, I've posted over there at DIY, but it seems my post has fallen on deaf ears since it's for a car and not home audio.

If some of y'all could possibly post over there and encourage a bit of conversation and show that there is a good deal of interest in this in a car, perhaps we could get a bit of talk rather than a bunch of folks who look down their noses at car audio....

durwood · 11-11-2006, 11:29 AM

On my way over....

durwood · 11-11-2006, 12:04 PM

Hey RED-

I posted over there so we will see. Also that wave program they are using looks like an EQ based program. You can pretty much use an EQ as a filter. FIR filters are harder to design than IIR filters- (a digital based analog filter/crososver) because there are not easy models to base them off of. It's probably easier to design an EQ based on FIR filtering. I wish I could explain it better but I am extremely rusty on my knowledge of it. I was doing a little research to jog my memory but I never seem to have time to get it done.

FyreDaug · 11-11-2006, 02:08 PM

Heres something that I dont know if it has been mentioned or not. Heres my situation:

I have 2x200gb hdd full of music, .ogg, .flac, .mp3, .wma. The oggs and wma are few and far between but between the mp3 and flac I have some problems.

The 31band EQ in winamp will ONLY have an effect on lossless music, IE, my flacs, I can also not use the winamp bass/treble controls (which I like to keep both at -4% just to take a little edge off, but sometimes I turn it down to -25% on the bass for some songs, as its just easier to fiddle with instead of opening the eq.

The mp3 songs work fine with the winamp controls, but have 0 effect with the eq. I tested this by obviously using a flac and mp3 of the same song (which Roxette- The Look happened to be the test subject) and clearly 31bandeq=flac files
winamp bass/treble = mp3 files

I used to use this 4front EQ. Its 10band, but im going to test it out again with mp3 vs flac and see if it works for both. If it does, it looks like I have to downgrade my EQ.

durwood · 11-11-2006, 02:14 PM

Quote: Originally Posted by FyreDaug

Heres something that I dont know if it has been mentioned or not. Heres my situation:

I have 2x200gb hdd full of music, .ogg, .flac, .mp3, .wma. The oggs and wma are few and far between but between the mp3 and flac I have some problems.

The 31band EQ in winamp will ONLY have an effect on lossless music, IE, my flacs, I can also not use the winamp bass/treble controls (which I like to keep both at -4% just to take a little edge off, but sometimes I turn it down to -25% on the bass for some songs, as its just easier to fiddle with instead of opening the eq.

The mp3 songs work fine with the winamp controls, but have 0 effect with the eq. I tested this by obviously using a flac and mp3 of the same song (which Roxette- The Look happened to be the test subject) and clearly 31bandeq=flac files
winamp bass/treble = mp3 files

I used to use this 4front EQ. Its 10band, but im going to test it out again with mp3 vs flac and see if it works for both. If it does, it looks like I have to downgrade my EQ.

Hmmm.. I used it sucessfully on mp3 files and cd audio files. I don't have any FLAC files. I'm using Winamp 5.24 and the vst plugin configured to use the free vst EQ from the first page of this post.

EDIT: I noticed every now and then it freezes on some mp3s when using ASIO output plugin only.

FyreDaug · 11-11-2006, 09:24 PM

"freezes" as in winamp locks up? I have that problem sometimes if thats what you are talking about. its kinda rare.

But it has NO effect on any of my mp3's, why would that be?

durwood · 11-13-2006, 08:11 AM

Quote: Originally Posted by FyreDaug

"freezes" as in winamp locks up? I have that problem sometimes if thats what you are talking about. its kinda rare.

But it has NO effect on any of my mp3's, why would that be?

Yes, Winamp locks up. Probably just bad MP3's. I don't really know though.

I am not sure about your strange problem. Just remember though that a 31 band EQ makes small adjustments versus a 10 band. If you adjust a bunch of bands that are close together then you should see a more drastic change. If you notice a difference on the FLAC files though then you should notice a difference on your MP3's on any changes you make. What is your software/hardware setup exactly? I need more information and I will try to duplicate your problem.

nubz69 · 11-14-2006, 05:44 PM

There is no need for a second computer. There is a need for a relatively powerful computer. I was able to run multiple plug ins as well as VSTi's on my old 1ghz AMD computer. What we are talking about here is very feasible with todays technology. I would post more of what I know here but I am moving to FL in Jan so I have very little time right now. I feel there are more then one way to achieve our goal. The questing I am pondering now is whither we should go about this project as an all in one solution (OS,media player,tuning,GPS) or should we attack this by adding to and modifying existing techniques? I feel the former would work better in the end but I feel that to truly make it would we would need to use a Linux based OS. The latter could work with windows or linux.

Abmolech · 11-14-2006, 09:23 PM

There are several reasons I decided to use a car pc for processing duties.

One of which is to do non-linear volume control off a single point. The idea is to maintain "C" weighting at any dB.

Is there a VST plugin available?

durwood · 11-15-2006, 07:41 AM

Quote:

One of which is to do non-linear volume control off a single point. The idea is to maintain "C" weighting at any dB

Could you elaborate why you want to use "c-weighting" over "a-weighting". Do you have any proof that the volume control used by the computer/program uses "a-weighting"?

BTW: I am not using the computer to do my volume control at the moment, but I will be hopefully in the future.

Abmolech · 11-15-2006, 11:13 AM

Most volume controls are "linear". Sure your pentameter is logarithmic, however so is dB rating.

Let us assume we set our system for "perfect" volume listening at a certain dB.
As soon as we change this dB (move the volume knob) then we start to move away from the "perfect" listening weighting.

http://hyperphysics.phy-astr.gsu.edu...nd/eqloud.html

The above site is quite good on human hearing. If you observe the loudness curves you will appreciate the different requirements and dB. The "standard" is 1000 Hz, as you change this dB notice the upper and lower frequency dB requirements deviate from the original point.

"C" weighting approximates these settings. (supposedly if you set your RTA microphone on this, you should aim for a "flat response")

How important is this?
I believe dB differences are the primary reason for a system sounding better/worse. In-fact I will go as far to say this THE main criteria for discerning difference between various electronic components. If they are level matched it is very difficult for human hearing to pick variations in most electronic equipment.

This loudness curve is the primary reason for the eq "smiley face" and peoples eternal fiddling with it. I suspect if this was setup to maintain this curve then much less "tuning" would be the result.

durwood · 11-15-2006, 11:58 AM

The reason I am bringing this up is that in SQ contests there is a section for linerarity at different volume levels. I had problems in this area at lower volumes. My volume control was adjusted using an Audiocontrol Master Volume control. It was a totally analog volume control. My guess is that it was linear.

I am interested in what you are saying because it could prove to be useful, but when you say "maintain c weighting" is that "c-weighting" to measuring equipment, or to the human ear (which is really a-weighting)? So you want a system that adjusts for equal loudness or basically alters the resposne based on the "Fletcher-Munson curve"? Am I understanding you correctly?

The problem you run into is that human hearing differs from measuring equipment. When they speak of C-weighting is good for home theater applications, then it goes against how we listen. How often do we listen at high volumes? Just because it has flat response doesn't always mean it sounds good all the time. Help me out here.

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