High End Carputer but faltering at the sofware bit

**frankmehta** · 02-02-2011, 07:05 AM

A HUGE helllo to everyone on mp3car.
I am actually in the process of making a massive leap in terms of source quality as I have replaced my Eclipse CD7200MKII with a carputer.
The setup is as follows:
1. Front Stage:
Illusion Audio CH-1 horns with (maybe) Alpine SPX17PRO/Dynaudio MW 162/Creative SDX7 (depends on what I zero down on, finally) woofers powered by a Genesis Stereo 60 and DLS RA20 amplifier respectively.

2. Rear Fill:
Morel Tempo Coaxial speakers powered by a JBL amplifier

3. Subwoofer:
JBL W12GTi powered by a Clarion DPX11551 monoblock amplifier.

The computer in question is a Core i3 based PC with an M4ATX power supply and an Asus Xonar D2X is the soundcard of choice.

I am using Virtual Audio Cable + AUDIOMULCH + Centrafuse as the front end to route audio through the soundcard.
I will be using VST plugins for the following:
1. Frequency allocation for each channel/Crossover etc.
2. Time alignment for each channel
3. 16/32 band eq for each channel

I have a few questions. Kindly help me solve these small niggles:
1. Can someone be kind enough to prepare a schematic diagram (audiomulch) for me, showing me the order in which the plugins should be placed, alongwith actual distribution of audio channels?? I am very confused with the whole 'sound-in' and 'sound-out' bit in audiomulch and the last time I tried, I kind of messed the output, where increasing the subwoofer level also increased the level in the right front speaker.

2. In audiomulch, should I select Directsound or Virtual Audio Cable as the source?

3. Virtual Audio Cable is very confusing, especially the option where one has to 'select' soundcards and turn them on and off. I am absolutely alien to using VAC. Which soundcards to turn off/ on? The soundcards shown are
1. Asus Xonar D2X
2. Realtek ALCxxx codec (the onboard audio)
3. ASIO4ALL

4. Can someone actually run me through how I should make the whole setup work? I have tried several permutations with VAC, Directsound, Asus Audiocenter etc. but I just can't get it to sound well. (most of the time, I don't even get any form of output)

5. I get a few pops and artefacts when I am using directsound.

6. I have good equipment but I am a really confused guy, since my first effort at putting the whole thing together sounded AWFUL.
7. What is ASIO4ALL and what part does it play in all this? How to get it to work??
8. Windows 7 or Windows XP?
9. DO i need to install the WHOLE software package that came with the Asus Xonar D2X (ie the driver + the control center software) or JUST the WDM drivers of the card???

Someone needs to sit me down (literally) and spoonfeed the whole shebang to me. I am at my wit’s end.
Let’s put it this way. I need guidance from the FIRST step (hardware and wiring is all perfect, I just falter at the software bit)

**soundman98** · 02-02-2011, 08:18 AM

no problem. you should have seen how confused i was when i first got into audio processing (not sure if it holds true for everyone, but this is something that i didn't fully grasp until i did it. reading about how to do it only confused me more..)

BEWARE!! this is going to be a really long post, and i tend to skip over things, or poorly format everything.. i will do what i can to try to keep some sort of order to it though..

i just posted/copied this thread on getting a basic audio setup in audio mulch-- it's very basic, but gives you something to start off with..

xp/win7? win7 .period. i don't remember all the technical lingo, but basically, the OS handles audio way, way better, which means that getting a sq setup in win 7 is easier.

in xp,i have read that it is best to bypass the os in the audio path, as the OS audio routing isn't the best. i never did it, so you'll need search some to get details on this..

one thing you didn't touch on is version of OS-- i believe that 32 bit is better, as it seems that more plugins have a better chance of working with it.

if you do end up using a 64 bit os, be sure to check the "only show x64 plugins" in kvraudio.com's plugin search engine. i know that one member did have issues with non-64bit plugins not working very well and causing odd problems..

plugin quality: most plugins are free, because of this, many either have glitches, or will result in a higher cpu load for that specific plugin. as i mentioned in the above linked thread, the karmafx series has seemed to be relatively glitch-free for me, and also has lower cpu usage then most.

that is not to say that they are the best set of plugins, but seems to be consistent enough to be a great starting point..

a good baseline for plugins-- with your i3, a good plugin setup should rarely rise above 20% cpu usage, and should never stay above 50%(though small spikes around song changes are ok). my pentium dual core(e5200) stays around 10-12% with 3 instances of band-pass x-overs, and 2 eq's..

most of your questions on setup are partially answered in the other thread i linked to on the basic setup, but if you still don't get something, let me know.

the pops/artifacts could be due to a low buffer size, or a high DPC latency:
http://www.thesycon.de/deu/latency_check.shtml

run this program, and it will tell you if there are device driver errors-- if you do have some errors, start disabling things like wifi, and wireless keyboard drivers first (my pc has a error from my addesso wireless keyboard-- the same one sold in the mp3car store)

for vac soundcard selection-- i believe your looking at the A4A control panel. the vac control panel should look like this:

the asio4all screen should look like this:

i think that's good for now. i'm snowbound, so i'll check this thread periodically..

**durwood** · 02-02-2011, 08:32 AM

You have to think of it in terms of a hardware and software combo otherwise it's going to be confusing. Here is the flow:

Audio player software -> WDM or KS audio stream -> soundcard -> DSP chip on soundcard for signal routing -> Hardware outputs (analog or digital).

What has to happen is:
1) Audio player software -> WDM or ASIO stream -> soundcard
2) Replace the DSP signal routing with the VST host + plugins
3) VST Host now acts as the DSP and sends the signal to the hardware outputs.

The only reason to use VAC or JACK is for soundcards that do not have the ability to internally "break" the connection of the audio signal going to the hardware outputs (set 2 bolded above). The drivers for the majority of soundcards are designed for the consumer who wants easy setup. If your card has the ability to access the DSP chip on the card in such a way to do this (ex. 1010lt, Audiotrak with directwire) then you don't need VAC. The Asus cards can do it, but you lose a pair of channels to make it happen. So use VAC as your soundcard in step 1 and your Asus as the hardware in steps 2 and 3. Yes you will need to install the ASUS drivers so you can use the built in ASIO driver for XP. WIndows 7 is a different story because ASUS removed ASIO driver. See these threads

http://www.thuneau.com/forum/viewtop...r=asc&start=30
http://www.thuneau.com/forum/viewtopic.php?t=218

**frankmehta** · 02-02-2011, 12:31 PM

gee, those responses were really of great help.
i was jus confused. Does the Xonar have internal routing or not?
and does adding VAC in the equation lower quality?? just asking, since i read somewhere that the xonar has internal routing and hence VAC is not required. 1 drawback of this would be that we would only be able to use 6 of the 8 channels of the xonar (since 1 and 2 are dedicated to WDM)
It's slightly confusing this.

DOES VAC have to be a part of THIS equation (with this hardware)?