PC Based 5.1 Active XO system.

mga2009

Member
2015-11-20 10:34 pm
Need some clarification from the experts here...

I am trying to assemble a 5.1 active XO, pc based media player...

I already have the 10+ channel amplification for my 5x 2 way speakers, and I was looking to buy 3x ADAU1701 DSPs to feed the amps, but realized the whole media I consume is PC based (netflix, plex, spotify, etc.), and that I could use my PC (Equalizer APO and rePHASE) as crossover, but the problem is that I need a 10+ channel DAC or multiple soundcards... So, what choice do I have?

a). 10+ channel DAC = too expensive, and beats all the purpose.
b). Multiple USB sound cards = this would represent a problem to configure multiple outputs without delay and configuration problems.
c). Get a 16 channel USB interface like the Behringer UMC1820.

Would this last alternative work? When I plug the UMC1820 will it be recognized with EqualizerAPO? As an USB interface, all the sound output's thru this interface? The price is very atractive, buty I don't what to spend that money if it's not going to work for me. I assume hte sound must be outputed as PCM, so no bitstreaming, and I will be limited to 24bit 96khz (not a problem and I will probably use 48khz).

So the chaing would be:

PC > UMC1820 > amps > tweeters and woofers

I am not looking uber audiophile quality, I just use it for movie watching and some music, but not critical.

Thanks in advance for your help!
 

jdarg

Member
2005-08-27 4:52 pm
I use the 7.1 Asus xonar mkii and it's great. You might want to pick one of for $100 and just go passive on one pair of speakers for now. If nothing else you can see if you want it layout more for the behringer then. Having come from a 4 out behringer 404hd, the Asus is an improvement in a couple of areas, but no experience with the 1820.

If you don't care about quality why are you going through the trouble to go active though?
 
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mga2009

Member
2015-11-20 10:34 pm
Also I do run everything through eapo with that setup works fine except when win10 upgrades and I have to relink eapo to the sound card and reset it to 8 channel.

Thanks for your reply!

Yes, I 've read very good comments on the Xonar, but where I live I can't get it, and the Behringer is widely available (the 404hd too).

Going active on LCR and passive on the surrounds is one alternative, and probably a good place to start. Thanks.

I would like to go active to properly tailor the XO on my room, and get the most out of my speakers. What I meant about quality, is that for now I am not concerned on the difference an audiphile DAC with discrete power supply and vaccum filed USB cable (read irony) might do versus a "pro audio" dac like a behringer and some cheap swedish class d amp.

Please, tell me more about your experience with the 404HD (for the price, it looks like a good start). Was it recognized by APO? It has balanced output, correct?

Looking forward to your reply
 

mga2009

Member
2015-11-20 10:34 pm
It was too noisy for horns but worked fine with eapo. The minidsp was much quieter, the xonar eliminated all noise and hiss.

Thanks for your reply.

I just bought a UMC 204HD very cheap so I will start from there...

What I could not find is if it outputs balanced signal or single ended, and also don't know if it can output 4 channels simultaneously, as the datasheet shows an A/B selector...

Anyways, its a start, and I will get left and right channels powered by 2x Anaview ALC0100-2300, and see how it goes with active XO. If everything goes OK, I might upgrade to the UMC 1820.

Thanks!
 

mga2009

Member
2015-11-20 10:34 pm
It will definitely work on a usb sound card, however one requirement for this mod to work correctly is that both cards should be able to start playing audio at almost the exact same time.
Since usb is a lot slower than pci, I'm not sure if you'll get satisfactory results, one sound card might lag behind the other.

I have this mod running on two Asus D2X cards, with a Crystek CCHD-575 24.576 MHz oscillator. The output of the oscillator is connected to the oscillator input of one card, then the oscillator output of that card is connected to the oscillator input of the second card, using a 100 ohm series resistor. I first connected it without the series resistor, and probably because of reflections back into the oscillator output, the primary sound card was playing audio twice as fast. I accidentally overclocked a sound card :)
The connection between the cards is done using a twin lead with Dupont jumper connectors. One lead carries the signal, the other carries ground, it's very important to have a ground wire in parallel to the signal wire in case of high frequency signals.

I tested the synchronization with headphones, I used a splitter cable to connect one transducer to each card, then listened if the sound was shifted to the left or the right. It was exactly in the middle, even after playing audio for several weeks.
 
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