[Dracule1]

Hi all,

I am trying to decide which is a better way to go for room EQ.  If I build a HD based music server with an external USB DAC, is there PC EQ software that processes equilization in the digital domain like the Behringer DEQ2496?  I would think that a dedicated PC software would have even more features and flexibility than the Behringer.  Thanks.

[woodsyi]

What music server ar you using?  I thought with foobar, you could use a bunch of plugin components to do DSP?

[smk5r]

The following links may help on PC based room correction, especially the how-to .pdf  for dummies (like me) utilizing Foobar.

http://www.mooneyass.com/DRC/DRCGuidev1.0.pdf

As far as I can surmise, product offerings from Tact, Behringer, etc. provide a relatively turn-key solution in comparison and possess correction filters that better reflect tendencies amongst recording engineers. At the same time, PC based correction provides for more flexibility (active crossovers, upsampling, etc.) with a steep learning curve when implementing. PC based room correction has also been successfully applied to Slimserver.

http://drc-fir.sourceforge.net/

http://en.wikipedia.org/wiki/Digital_room_correction

http://www.duffroomcorrection.com/wiki/Main_Page

Good luck.

[sts9fan]

Do you have a link on how to do this with slimserver?

[smk5r]

http://www.duffroomcorrection.com/wiki/User:Hpyle

Once you have the correction filters, it's exceedingly easy to implement. Hope that helps.

[Dracule1]

  Thanks everyone for the helpful info.  Looks like PC based software EQ is more complicated than I thought.  I would like to put together a PC based music server feeding a USB DAC, but there's seem to be alot of work involved from selecting the right PC, HD, CD-ROM, appropriate software, etc.  Has any manufacturer come up with a reasonably affortable (ie, less than $1000) PC based music server?  Or can someone describe what he is using as there PC based server?  I've done some research but there's too many choices out there (but no dedicated PC music server), and I don't know which is good for an audiophile based system.  I suppose I can use the Behringer with digital output from a PC, but I would not know how to connect USB to AES/EBU interface that the Behringer uses.

[Dracule1]

Hi,

I just did some research on the Olive Musica, a hard drive based music server with 160 or 250 GB storage, built in DAC (Analogue Device, OK quality), linear power supply, DVD/CD R/W drive, and cool looking display on the unit, etc.  I was really thinking this might be the answer to what I was looking for, but unfortunately, although it has two USB ports, they can't be used to feed a USB DAC.  What was Olive thinking?  Only digital out available are SPDIF RCA and Toslink, like your standard CDP.  May be in the future they may upgrade the USB to feed DACs.

[kfr01]

This thread, AFIAK, reflects the state of the art of PC-based eq (and crossover) technology for home audiophile use:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=63078

It requires a decent amount of processing power, a professional quality soundcard, and expensive software.
There is -not- an inexpensive and easy to use PC-based solution, ATM.

As mentioned above, there -are- expensive consumer devices (Tact, DEQX).

My strategy:  Build a cheap and quiet pc to rip, store, and play music.  You don't need to get "the right" of anything.  Any stable and quiet PC will do.  If you need help selecting the right components see Arstechnica's system guide:  http://arstechnica.com/guides/buyer/system-guide-200606.ars

Exact Audio Copy, the ripping software, is easy to setup.  Buy an inexpensive USB->SPDIF converter (m-audio transit, redwine usb select, empirical offramp) and a decent external DAC.  Work on passive room treatment.  and.... 

Wait for a better and more affordable solution while moving to and enjoying lossless pc audio in the meantime. 

I really think digital eq and crossover products are at the -bleeding- edge for regular consumers right now.  There's enough interest in room acoustics and digital eq that we'll see some innovative and affordable products in coming years.

This probably isn't the answer you wanted, but it reflects my current analysis and conclusion. 

[ctviggen]

It depends on how much time you have.  Given time, you could implement these functions in a PC and have the benefit of being able to do so for 5 channel if you desire (something not even TACT can do as of yet, at least not for a reasonable fee).  It's just very time consuming.  Also, that Slimserver tweak appears to be for one system.  I use two different SBs playing in three different locations.  I don't think I could use that system.

[dwk]

This thread, AFIAK, reflects the state of the art of PC-based eq (and crossover) technology for home audiophile use:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=63078

Except at the very end, that thread is out of date. It's definately groundbreaking in some sense, but as evidenced by the fact that ShinObiwan bailed out, it's far too finicky for everyday use.

There is -not- an inexpensive and easy to use PC-based solution, ATM.

There is now.  check out www.thuneau.com  - I've been beta testing this for a while and aside from DRC/Room Correction (you need a separate convolver like SIR for that) it does everything you need for a great 4-way xover system. I'm using it on a homebrew version of Tom Danleys Unity Concept system, and hence need tons of eq and delay, and it is accounting itself very very well.
 I've been around PC xovers for a long time - from the initial BruteFIR release for Linux ~8 years ago, and this is hands-down, flat out the best thing I've seen.

I really think digital eq and crossover products are at the -bleeding- edge for regular consumers right now.  There's enough interest in room acoustics and digital eq that we'll see some innovative and affordable products in coming years.

This probably isn't the answer you wanted, but it reflects my current analysis and conclusion. 

Still cutting edge, but I think Jan's Allocator really takes a huge step forward in making it available to non-gurus. The DRC/room problem is still there, but Denis' DRC code is pretty much state of the art in terms of results, it is just a bit opaque in terms of configuration and setup.  Still, you can get everything out of Allocator that you'd get out of a DCX/DEQ combo, plus the added bonus of phase correction as well. In this context, I'm not sure DRC is 'necessary' as much as 'icing on the cake'.

[kfr01]

Dwk:

Thanks for correcting me.  I must admit that I haven't been tracking the issue weekly.  (It appears that the demo of the software you linked to just came out within the past month.

In any event, thanks again.  I'll have to download and check it out myself.

Karl

[dwk]

In any event, thanks again.  I'll have to download and check it out myself.

Karl

No problem - I'm very impressed, and so am trying to spread the good word. It does still need a pro-grade card and runs via ASIO/VST so it's still not really a consumer approach, but IMHO it's a noteworth achievement.
 
I hope it works out you - there seem to stil be a couple folks that are having some issues in their setups, but I'm using it with an EMU1820M and am having great results.

[pugs]

http://www.duffroomcorrection.com/wiki/User:Hpyle

Once you have the correction filters, it's exceedingly easy to implement. Hope that helps.

Are the filters an actual piece of equipment or is it software?  Have you tried it using Slimsever?  If so, how did you like it?  If it works just as good as a TacT or Behringer, that would be awesome.

[smk5r]

Are the filters an actual piece of equipment or is it software?  Have you tried it using Slimsever?  If so, how did you like it?  If it works just as good as a TacT or Behringer, that would be awesome.

Software--the results of running sound sweeps to generate the correction. I'll attempt to implement DRC for Slimserver this weekend--I'll let you know how it goes.  If successful, I'll try and compare it to running Foobar with DRC into my USB Dac. I don't have a Tact or Behringer, so that comparison will be left for someone else. As an aside, I spent about $150 on getting everything I needed to generate the correction. This price does not include the cost of my PC or USB Dac.

[inguz]

You need measuring equipment to record the room response to a sweep from each loudspeaker.  Thereafter it's all software... process the measurements to get an impulse, run the impulse through DRC to make a filter, then the filter processor (convolver) sits quietly in the SlimServer turning regular bits into magic bits.  (My implementation is Windows-only, since I only run slimserver on Windows.  Want to beta-test and have measurement mic etc? drop me a line).

Unfortunately I don't have a TacT to compare with...

IMHO there's a difference between "EQ" and "room correction" which is important.  Room-correction like DRC, TacT etc works on phase as well as magnitude.  Regular EQ like the DEQ2496 doesn't try to remove the effect of early reflections.

-hugh / inguz