HTPC based full digital 12 channel room correction

[totalr]

Hi there, please advice if that is realistic to make PC based high end room correction device with like Lynx AES32 card. It could be connected to 12 digital output channels of the surround processor (modified marantz 8802A) and output 12 SPDIFs to external DACs.

Goal is not turn off interal Audyssey and tune surround PCM streams with some PC software like Accourate.

Will that be on the same league as Trinnov/Datasat/JBL Synthesys?

Delays for each channel could be controlled with Marantz.

Another possible question is PC hardware with all noisy power supplies etc, how much jitter it adds to the digital streams, but maybe its not a big deal.

What multichannel room correction software is the best currently?

 

Whole goal is to make budget alternative to highly expensive processors like datasat SA20i or Trinnov Altitude32 and play DTS:X/Atmos with Auro 3D streams.

I believe the main difference between them and budget marantz is room correction filters and DACs, should not be much of the other difference...

 

 

thanks!

[Nyal Mellor]

Been there, done that http://www.acousticfrontiers.com/201366how-to-replace-your-home-theater-pre-pro-with-a-htpc/. IMO too many issues with it...now using a Datasat

[totalr]

Hi Nyal, thanks for reply. Yes, i read that article but my idea is a bit different. I am not using HTPC as a source/DTS encoder processor since there is no DTS:X/Atmos and Auro3D software available. I just want to make a PC based room correction device which will be better or similar to top of the line current hardware based units on the market . I asked many installers and all of the say that the main different between pre/pros on the market is a room correction/equalization/filters. So if using digital outputs with out any processing all pre/pros will be the same. Even Auro tech confirmed that. As for Datasat then their Dirac is good (better than Audyssey) but still much worser than JBL Synthesys Equalaizer SDEC-4500P. So many high end installers are using Datasat with turned off all of its Dirac and internal filters. So why pay 20+K for that if 3k modified Maranz could do the same? (even more now since there is DTS:X already available). I believe i7 HTPC with Lynx could do room correction not worser than SDEC just need proper software but probably even better since there will not be any ADC/DAC conversion in it.

[Audio_ELF]

Sounds like you are entering a world with a lot of un-user friendliness and a bag of hurt.

 

Why not take your Marantz 8802A and use a pair of MiniDSP Dirac 88A?

 

You say "As for Datasat then their Dirac is good (better than Audyssey) but still much worser than JBL Synthesys Equalaizer SDEC-4500P." and then "I believe i7 HTPC with Lynx could do room correction not worser than SDEC just need proper software but probably even better since there will not be any ADC/DAC conversion in it." Well I think you have already noticed that what is the issue is software. Everything these days uses fairly common hardware; its the software / processing that varies.

 

Options for room correction within PC hardware is limited. DIRAC for example (afaik) doesn't allows external (multi-channel) input with multi-channel; and is limited to 8 channels.

[totalr]

thanks for reply, i agree its all about software.

 

so my main question is: Is some software PC solution will be better than hardware Dirac or even Trinnov?

For example Accourate is using complicated FIR filters, a lot of analyzing etc. It looks like they are on the same league..

 

Then , the whole reason to do all of this is to use external good DACs, so cheap minidsp dirac with analog in/out will kill the whole idea.

It should be full digital for input and output.

MiniDSP is having OpenDRC digital platform (miniShark), it is 2 channel and i can probably use several units but DSP is weak comparing to PC and if software is the same or even better then PC with Lynx should do better job.

[Nyal Mellor]

Personally I don't think it is possible to get better results than using an RS20i or Altitude by cobbling something together with a HTPC.

 

There's a big problem with spatial audio and HTPC, as you will have to send a bitstream from the HTPC to the pre-pro, and you can't do any processing in the HTPC on a bitstream. That means no room correction or signal manipulation. Even if Atmos or DTS.X decoders were available for the HTPC I do not think it would be worth it, as my experiment showed.

[totalr]

You might be right after all but still i believe there is a chance to make it right and simple.

Room correction is processing decoded streams to each speaker.

I mean audio path is as follows:

 

Medial Player(Source) HDMI->3D processor(Marantz?) SPDIF Outs->Room correction HTPC with Lynx32 SPDIF Outs-> Multichannel DAC

 

As you can see room correction does not care about original datastream, it is working with decoded PCM signals.

 

I spoke with Uli from Accourate and he said the only problem here is audio delay for phase correction. We need to output sound in advance to video and delay could be up to 1.5s. But it could be done in Media Player. I just checked and even my old Dune 3D has such a capability, it is working for 2 seconds both ways.

 

I do not see that Datasat could do for room correction and Accourate could not, at least in the spec sheet.

[mansr]

I spoke with Uli from Accourate and he said the only problem here is audio delay for phase correction. We need to output sound in advance to video and delay could be up to 1.5s. But it could be done in Media Player. I just checked and even my old Dune 3D has such a capability, it is working for 2 seconds both ways.

 

The Marantz should have an audio delay setting if the firmware is anything like that of the integrated AVRs.

[totalr]

The Marantz should have an audio delay setting if the firmware is anything like that of the integrated AVRs.

 

I just checked manual and it is 200ms for the lip sync, probably not enough.

[Audio_ELF]

I just checked manual and it is 200ms for the lip sync, probably not enough.

You're likely to need to go the other way as well as the audio processing may end up delayed with reference to the video.

 

Of course you could look at the Trinov processor... That IS a PC with custom hardware (you can see the PC backplane.

[Loafmeat]

Hello I am new here

 

I have done the following:

 

 

You can see my setup here:

diyAudio server HTTPS page

 

HIFI-FORUM » Do it yourself » Lautsprecher » Aktive Frequenzweiche per Standard Software mit GUI

 

Sorry it is in German

 

You have

4 x 2 crossover

many parametic equalizer

limiter

....

much more

 

HDMI 8 Channel output

8 Channel analog output

 

For activating for example 2, 3 or 4 way loudspeaker

 

or see my discussion here:

http://www.diyaudio.com/forums/pc-based/256809-setting-up-pc-based-multichannel-dsp-system-10.html#post4644330

with the following posts

 

with HDMI 2.0 it should be possible to work with 32 channels

 

Regards

Loafmeat