[JoshK]

I've been doing a bit of research lately contemplating whether or not to build an audio pc and/or HTPC and what all I want to do with it.

I came across some info and pages on how people are using PC's to do Digital Room Correction (DCR), XO, processing, etc.  There is nothing new about this, except in some of the end results I came across (at least for me).  There seems to be a sect of the community that are building such audio digital processors as appliances using Linux, BruteFIR &/or AlmusVCU.  The end results is they function like a 'set top box' or standard component.  

Some interesting things I saw:  

almusvcu

Tutorial on setting up DRC pc

Fantastic resource; ewildgoose's wiki page on DRC (also has the memory stick app)

Great thread on AVS forum on HTPC DRC for MC apps

Linux based HTPC apps
KnoppMyth set top box

MythTv

Anyone thinking about doing something like this?

Seems that a number of builders who have built such an appliance have sold their TACT's or at least replaced their TACT's in the system and describing how they feel the DRC box is better.   In all fairness this would be closer to a DEQX due to the SC & XO abilities this opens your world to, and then their is also Ambiosonic and Ambiophonic applications as well (this is way cool IMHO!).

All of this is open source and generally free software, being developed by the community.  I really like this idea.  Of course it will require a learning curve a bit beyond that of even the DEQX, but the upside seems limitless.

I really like how those have stuck with the set top box approach so that the idea that a PC is needed in the playback chain is never noticed. Also, there is a site about how one guy built a PC to run Linux and BruteFIR off a memory card so no harddrives or fans were needed in the playback chain, so the component is completely silent and boots in seconds.  

Now I just have to decide whether I want to incorporate my HTPC idea into such an appliance or do that seperate.  
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[brj]

Hmmm.... I've been contemplating a Linux based media PC, but I hadn't considered taking it quite as far as what you just described.  I didn't realize that people were implementing the crossover in the media PC.  That really opens up a lot of options.  I like everything I've read about the DEQ/X, but for its $3500 price (pre-amp version) you can spec out a very nice media PC a greater feature set, as well as more flexibility and upgradeability.  You will definitely have a larger learning curve and time investment, but I personally wouldn't find that objectionable.

I'll read through your links when I get home from work tonight, but the one piece that I didn't see you mention was driver correction (separately from room correction).  Have you seen anyone implement this in a media PC?

Thanks for posting your research!

[woodsyi]

Josh,

It sounds facinating.  If you can come up with a blue print or, better yet,  come up with a reasonable price for a built kit like you are doing with the Pro2 transport I would be the first in line for one.  I just don't have the knowhow, skills or time to learn such a project but I am interested in the final product.  Of course, it would have to be cheaper than DEQX.  

[csero]

For audio only an easier soulution is audiomulch

http://www.audiomulch.com/index.htm

Small, reliable, fast and cheap. Just add VST plugins for any extra processing or routing and multichannel soundcard and you can do anything, even MCH convolution for speaker correction or ambience reconstruction  ( Voxngo Pristinespace) and crosstalk cancellation (Amphiotik Enhancer ST 1.11, WaveArts).

But still far from user friendly . PCs just too much hassle for me for listening.

[JoshK]

For audio only an easier soulution is audiomulch

http://www.audiomulch.com/index.htm

Small, reliable, fast and cheap. Just add VST plugins for any extra processing or routing and multichannel soundcard and you can do anything, even MCH convolution for speaker correction or ambience reconstruction  ( Voxngo Pristinespace) and crosstalk cancellation (Amphiotik Enhancer ST 1.11, WaveArts).

But still far from user friendly . PCs just too much hassle for me for listening.

Thanks Frank, I'll have to read through the audiomulch site and see if I can get a handle on what that will involve.  However, as you said PCs are a hassle which is why I referenced a lot of the stuff I did, because that was the goal around which a lot of this was built, to make it function not like a PC but more like a DAC/processor.  

The solution that uses the USB memory card has no PC like interface at all and you wouldn't know that it was a PC if you didn't have to build it yourself and after having read through the instruction it really doesn't seem as hard as you might first think.  

I am trying to figure out though the challenge of finding the appropriate sound card and volume control.

[JoshK]

Josh,

It sounds facinating.  If you can come up with a blue print or, better yet,  come up with a reasonable price for a built kit like you are doing with the Pro2 transport I would be the first in line for one.  I just don't have the knowhow, skills or time to learn such a project but I am interested in the final product.  Of course, it would have to be cheaper than DEQX.  

Two quick notes

#1 the CD pro kit isn't my kit, I just offered to build the kit for people

#2 there is zero chance i'll be offering this kind of kit.  Sorry but WAY too much effort on my part for too little if any return.

I will however consider documenting and creating a manual or story of how I build mine if I decide to.  

If this is going to be an audio component and not a HTPC or AudioPC the solution is much simpler and probably even better.  There has been some chat about a USB, FireWire or Cat5 input interface so that an AudioPC or HTPC can interface in a more SOTA way.  This would be ideal and would allow the dedicated processor to act like a SOTA component and not a PC.

[csero]

Josh,

Robin Miller has a 12 channel AlmusVCU box with  a 4*32 char LCD display only and remote but still PITA. Adjustments like individual or all channels volume control, swithing between listening modes etc, are hard to do.  
A processing box has very different user IF requirements than a PC. Especially if you want to cram all the functionality into one box, you almost always end up in front of the big screen for the smallest adjustment.

[csero]

... unless you invest the time and effort to develop a genuine UIF with all the bells and whistles, but without the complexity. But I don't have time for that.

[JoshK]

Josh,

Robin Miller has a 12 channel AlmusVCU box with  a 4*32 char LCD display only and remote but still PITA. Adjustments like individual or all channels volume control, swithing between listening modes etc, are hard to do.  
A processing box has very different user IF requirements than a PC. Especially if you want to cram all the functionality into one box, you almost always end up in front of the big screen for the smallest adjustment.

Yeah I understand your point.  My idea was to do the MCh VolCon seperate and there is a nice kit and a few schematics to do that reasonably inexpensively.  Individual channel level would be a set once and forget plan on the pc proc.  Adjusting for listening mode in ambient surround wouldn't be addressed in my idea, but then most of the users here would probably never venture that road in all honesty.  It would certainly be cool to have your style control with the power and flexibility that a PC allows.  

I personally don't want the PC interface except for setting up and then it is cool.

[sunshinedawg]

I couldn't get the Amphiotik Enhancer ST 1.11 plug-in to work with Audiomulch.  Is there something I need to configure or do I just drop it in the vst plugin folder? After I put it in the folder and went to settings, it doesn't recognize that it's in there, so there is no way to configure it.

[Jon L]

The most useful and important feature would be a main software that has intuitive UI where all the little (but crucial) steps have already been set up and integrated, so that a moderately computer-literate user can click only a couple of times to get most things done.

For example, a software that already incorporates the PC crossover and DRC into a player like Foobar, which already has everything set up for ASIO, EAC w/ Flac conversion.  So instead of going through dozens of complicated steps to get x-over and DRC working with Foobar, all you have to do is click a couple of times to bring everything up and going.  For x-over, there HAS to be safety features to 100% prevent full signal going to your tweeter, etc.  A supplied (rental?) microphone/mic preamp would be essential for DRC also.

Even I, who use audio PC regularly, can't seem to get enough motivation/time to set up DRC/x-over and find the right mic/preamp.

Bundle that kind of easy-to-use software with decent hardware  at a reasonable price, and many more people will try this HD route.

[csero]

The most useful and important feature would be a main software that has intuitive UI where all the little (but crucial) steps have already been set up and integrated, so that a moderately computer-literate user can click only a couple of times to get most things done.

 

This part cost $2900 in the DEQX, the remaining $100 is the filters algorhytms, DSP, boxes etc.  

[CSMR]

If you used something like the 1820m you could have the first pair of outputs for headphones and then the rest for speakers. Then if you sent in normal stereo output by mistake your speakers will still be OK.
Than I suppose something like foobar's convolution would be best, unless someone has implemented an advanced equalizer which can create and equalize many channels. Unfortunately convolution seems hard to set up even in stereo mode.