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[Nyal Mellor]

Some of you may know that back in Feb of this year I started a mini-project to see if I could replace a pre-pro with a home theater PC. See '[url = "http://www.acousticfrontiers.com/whats-new/2013/2/11/deconstructing-the-home-theater-pre-processor.html"]Deconstructing the home theater pre-processor[/url]'.

The experiment has been a resounding success. I've been using the PC in our demo room for around three months now with no hickups, crashes or anything that would make me worry about recommending it as a solid solution. The quality is good enough that it has replaced my other music server (Mac Mini, iTunes, Pure Music) and so now I am using one server for both music and movies. It's really nice to be able to rip blu-rays to a server and be able to choose scenes as needed and skip all the introductory screens. A poor man's Kaleidescape.

The downside is the large amount of configuration that needs to be done to get everything to work. Thankfully I've figured all of this out and documented it in a blog post on my website:
http://www.acousticfrontiers.com/home-theater-blog/2013/6/6/how-to-replace-your-home-theater-pre-pro-with-a-htpc

how to replace your home theater pre-processor with a HTPC.

Take a look and leave a comment either here or there!

Without JRiver this would have been impossible but the program's flexibility and DSP power are amazing!

Next up I am going to start looking at what benefits, if any, these new fangled full range room correction plugins like Dirac Live and Audiolense can offer. I am personally not convinced theoretically about full range room correction but given the level of interest in it generally I figure I should at least try these things out, do some measurements and report back my findings.

[Vocalpoint]

Wow - fantastic documentation. I have just done the same with a new HTPC here and this is perfect as I continue to struggle with a number of issue with our machine.

BTW: Your website domain gives a very nasty "Get Me Out Of Here" warning in Firefox as if it's some kind of attack site. I went ahead anyway

Cheers,

VP

[Nyal Mellor]

BTW: Your website domain gives a very nasty "Get Me Out Of Here" warning in Firefox as if it's some kind of attack site. I went ahead anyway

Cheers,

VP

Really? How strange. I should look into that some more...

[Matt]

I just want to lend my support and also thank you for mentioning JRiver.

I'm a big fan of using a computer as the brains in the home listening theater or listening room.

Good luck and let us know if there's ever anything we can do to help you out

[slarti05]

Dear Nyal.

Thanks for the very helpful documentation on building a HTPC.

But besides my enthusiasm on your detailed report, isn't there the catch that it is not really a pre/pro?
The one feature that's missing is the cabability to connect external devices, like a PS3 or an external sat receiver (and then route both the video and audio signal via JRiver and let the HTPC do decoding, bass management etc. )
I'd spent quite some time trying to set this up recently, but I miserably failed... and now went back to having a prepro once again...

Do you have any thoughts or ideas on this?
Kind regards and thanks for your nice work
Slarti

PS: As an beside -I'd like to encourage you to test the DRC programs you mentioned: I've started using digital room correction for stereo listening about half a year ago, using Acourate, and JRiver as the convolver. The increase in sound quality of this approach (I've only tested Acourate) is just amazing.

[hulkss]

The one feature that's missing is the cabability to connect external devices, like a PS3 or an external sat receiver (and then route both the video and audio signal via JRiver and let the HTPC do decoding, bass management etc. ) I'd spent quite some time trying to set this up recently, but I miserably failed... and now went back to having a prepro once again...

Yes, that is the big limitation. I tried WASAPI loopback recently which should ideally allow playback of other software on the HTPC. The audio stuttered and was unuseable just trying to play a YouTube video from IE (I am using convolution). So I can play audio and video directly in JRiver and that's it.

[BradC]

have you tried the acourate convolver
http://www.audiovero.de/en/acourateconvolver.html

similar functionality to loopback, but apparently works. Haven't tried it myself, as don't have the requirement.
It was developed so people can use multiple audio sources.
Don't know how it would go syncing with video. In principle it should work with JRiver's video delay
Is there any way to have a hdmi input on the PC?

[slarti05]

Hi Brad,

I do use Acourate and AcourateConvolver, but the problem isn't to get a signal out of the PC, rather it's difficult to get it in, and here acourateConv cannot help you.

What I didn't manage to do is get an external Dolby Digital (or dts or,or,..) signal into the PC, let some software decode it (JRiver in particular) and do the playback via a soundcard (RME Fireface in my case). Therefore, your question regarding an HDMI input on a pc is actually an excellent one - that could do the trick... I used a laptop, so I couldn't test this.

Slarti

[Z0001]

Very interesting. I was looking at getting an AVR, but wonder whether it's worth considering the MC as a pre-pro.

So as I see it I'd need a multichanel soundcard (i have a Xonar ST), a multichannel DAC, a multichannel power amp and some method to source switch since I use other hi fi separates as well as the HTPC.

And I'd need to do this on the same budget as a good quality AVR.  Doable?? Or am I dreaming, and should just get an AVR?

[Nyal Mellor]

Dear Nyal.

Thanks for the very helpful documentation on building a HTPC.

But besides my enthusiasm on your detailed report, isn't there the catch that it is not really a pre/pro?
The one feature that's missing is the cabability to connect external devices, like a PS3 or an external sat receiver (and then route both the video and audio signal via JRiver and let the HTPC do decoding, bass management etc. )
I'd spent quite some time trying to set this up recently, but I miserably failed... and now went back to having a prepro once again...

Do you have any thoughts or ideas on this?
Kind regards and thanks for your nice work
Slarti

PS: As an beside -I'd like to encourage you to test the DRC programs you mentioned: I've started using digital room correction for stereo listening about half a year ago, using Acourate, and JRiver as the convolver. The increase in sound quality of this approach (I've only tested Acourate) is just amazing.

I think you can use JRiver's ASIO line in to route external audio through a soundcard into JRiver. I have not tried it yet though. Video in any event would go straight from source to display or if the display does not have enough inputs then to a switcher.

I definitely will be trying the DRC programs. My room is already fully acoustically treated so it will be interesting to see what difference room correction makes.

[Nyal Mellor]

Very interesting. I was looking at getting an AVR, but wonder whether it's worth considering the MC as a pre-pro.

So as I see it I'd need a multichanel soundcard (i have a Xonar ST), a multichannel DAC, a multichannel power amp and some method to source switch since I use other hi fi separates as well as the HTPC.

And I'd need to do this on the same budget as a good quality AVR.  Doable?? Or am I dreaming, and should just get an AVR?

It's not an inexpensive proposition to do what I have done. I would say the PC parts alone were over $2k. However my target was not a good quality AVR it was the Classe, Bryston, DataSat processors of the world.

An AVR would be cheaper I think though I doubt the quality would be anywhere near as good.

One could probably put together a $4k HTPC and external multichannel DAC package that would equal the quality of any Oppo / 10k pre-pro combination and kick it's ass for DSP flexibility. Obviously you will still be limited by the lack of inputs.

[BradC]

Hi Brad,

I do use Acourate and AcourateConvolver, but the problem isn't to get a signal out of the PC, rather it's difficult to get it in, and here acourateConv cannot help you.

What I didn't manage to do is get an external Dolby Digital (or dts or,or,..) signal into the PC, let some software decode it (JRiver in particular) and do the playback via a soundcard (RME Fireface in my case). Therefore, your question regarding an HDMI input on a pc is actually an excellent one - that could do the trick... I used a laptop, so I couldn't test this.

Slarti

I am surprised that you had trouble getting audio in with a fireface. I have a fireface 800 and it has optical and coax digital inputs. I assume you tried these.
Could you elaborate on the problems you had with audio in

[packux]

BTW, it is all too possible to get HDMI signal into the PC with something like the following

http://www.magewell.com/hardware/xi200de-hdmi/xi200de-hdmi_features.html?lang=en

[retro]

BTW, it is all too possible to get HDMI signal into the PC with something like the following

Interesting..!
They even have cards with quad hdmi-inputs, as well as Ultra HD cards..!!
But will they pass on both audio and video from a stand-alone BluRay-player..?

[packux]

Well, now that we found the interfaces, we still need some facilities from JRiver so as to implement a complete multichanner pre.

I propose to open a new thread with feature requests (or a wishlist) for v19.

[mojave]

But will they pass on both audio and video from a stand-alone BluRay-player..?

Why would you use a stand-alone Blu-Ray player to pass stuff to JRiver? Just use a Blu-ray drive in the HTPC. You might want this for cable or satellite boxes, though.

It says it supports LPCM for audio. This means the audio has to be decoded first by the cable/satellite box and will be changed to 16 bit 48 kHz PCM per HDMI specs.

[Sandy B Ridge]

I'd be wary of these HDMI capture devices for this use. The website and user documentation mention nothing of HDCP compliance. I bet you that when your bluray player or settop box realises that it is attached to a capture device and not a TV (HDMI 'sink') that you will get no output whatsoever. It is likely to fail the HDMI/HDCP handshake.

It's fine to capture non-HDCP HDMI sources like your Video Camera, and the website/userguide is careful to only show a videocamera, but probably not a HDCP needy device.

I'm sure there are HDCP 'strippers' out there, but it is another bit to put in the chain (and potentially fail). Pre pros are meant to pass the HDCP from the last device in the HDMI chain (the 'sink') to the player via the handshake. These capture cards I don't think can do this. But maybe some can?

SBR

[crawf1982]

Nyal,

It's great to see a professional getting excited about this subject and thank you very much for the documentation you have posted so far. I will be following your blogs with great interest!

I have been using an HTPC as my main source for about 10 years and I decided to go down the "PC as a processor" route shortly after the HD audio formats were announced. At the time I was outputting the audio from the HTPC via coax digital into an Arcam processor and then on to my active speakers. The only viable PC option I could find at the time was an M-Audio Delta 1010. There are Windows XP drivers for this device that include the same kind of bass management options that my processor offered.

The 2 niggling issues are that the bass management disappears from the drivers after Windows XP and I have never found a way of controlling the volume apart from in the system tray. However, neither of these issues were deal breakers for me. I picked up a second hand Delta 1010 for a fraction of the price I sold my processor for and gained a much more "future proof" solution offering up to 8 channels, should I ever need them.

I had been happily running this system up until a few months ago when I discovered JRiver. All of a sudden I was able to move to Windows 7, install the appropriate ASIO driver and set up everything else in the JRiver options. I can now even control the volume with the buttons on the side of my phone with he help of the Gizmo app. Fantastic!

JRiver really has opened the doors for anyone wanting to use an HTPC as a pre-processor. There are plenty of pro-audio devices available to use as the hardware and you can get some serious gear for your money. On the second hand market, M-Audio Delta 1010s go for about £100 on eBay and I have literally just sourced a Lynx Two-B card for £350 which I am looking forward to trying in my HTPC!

[Nyal Mellor]

Another option would be to use a HDMI audio 'de-embedder' and switcher for signals that originate outside the PC, kind of like the Meridian HD621.

The main non-blu ray source most people need is a cable or satellite box?

[JJJ]

Nice one Nyal.  I've very much steered away from the use of my "audio server" for video as I think an Oppo has far better video processing than a simple motherboard.  For audio, however, it's a different story with my Juli@ XTe card and I look forward to testing PEQ (using REW to measure room and develop filters) while I wait for Theta to implement Dirac Live. It will be a long time before I ditch my CB III HD !!

How do you find the Streamcom case? I think their finish is awful and will be replacing mine with one of HD-Plex's new brushed aluminium fascia models. Also, I note your choice of power supply.  Have you tested how much power the HTPC draws? I'm popping in a full linear power supply into my build. I'd be interested as to how much current yours draws.

Steve

[Buckster]

does JRiver boost the LFE channel by 10dB as required when decoding DTS/D.Digital etc etc ?.  This is where I had issues when trying to use my HTPC as a processor - I couldn't get the LFE channel levels correct without JRiver audio engine detecting clipping.  I believe normally when you unpack any of the lossless/lossy multichannel formats such as DTS/D.Digital - the LFE channel is at -10dB and requires the processor to apply a +10dB correction, most modern processors do this, but older ones (like mine) - or if you are going direct to the sub and direct to a power amp to the speakers the correction wouldn't be added ?.  If you are using the subwoofer for any other sources, or are using any crossovers - you can't correct this via output levels it has to be done to the actual LFE channel not the Subwoofer channel, as:

If you are using bass management within JRiver then:

Subwoofer output channel output from JRiver = Crossed Over Bass + LFE channel (but at -10dB)
If you set the Subwoofer level to be correct - the LFE channel will be -10dB
If you boosted the Subwoofer channel by 10dB the LFE channel would be correct,but the crossed over bass would be +10dB

so only way I could find was to boost the LFE channel in "Room Correction" in JRiver - but no matter whether I set all channels to 0dB - except for the LFE channel which I set to +10 - or whether I set all channels to say -7dB and LFE channel to +3dB, I get clipping detected by JRiver Audio Engine, it applies a fix, and effectively its reducing the overall dynamics.  Your usage is different to that I attempted - but after reading through your blog -  I'm not sure how you got around this issue please ?

Please see this thread:

http://yabb.jriver.com/interact/index.php?topic=70334.0

and in particular this part of Matt's Post (hope he doesn't mind me quoting him)

""The simple summary is that Media Center will normalize all signals (those with native LFE, JRSS signals, etc.) so that coming out of the 'Output Format' DSP it will be assumed that something later in the chain will make the subwoofer +10dB.""

[mojave]

You cannot increase a digital signal. In order for the LFE to be +10 dB in relation to the other channels, then the other channels actually have to be reduced by 10 dB. To preserve headroom in all channels, JRiver expects the the subwoofer output be increased at the subwoofer amp by 10 dB. This is the way it is done at movie theaters and keeps all channels at their maximum levels.

Think of it as all channels are at maximum level and the LFE still needs 10 dB more output. The LFE channel is recorded at 0 dB, just like the rest and is not recorded at -10dB. However, at 0 dB it still needs more output. When you understand this you realize why "something later in the chain will make the subwoofer +10dB." A receiver does this by adding an extra opamp that boost the voltage for the subwoofer output.

If you don't have enough gain in your subwoofer amp, then you can increase the volume in either Parametric Equalizer or Room Correction. Again, the volume is all relative. If you increase the subwoofer in Room Correction by 10 dB, JRiver will actually reduce all channels but that one by 10 dB. Like wise if you increase the subwoofer by 3 dB and reduce others by 7 dB, JRiver will still reduce all other channels by 10 dB since the relative levels is what is used.

When using bass management, JRiver correctly reduced the level of channels that are being mixed with the LFE channel by 10 dB. This means if you are calibrated properly that the bass will be the same whether you use bass management or not.

You can use Tools > Advanced Tools > Audio Calibration > Volume Calibration to check your levels.

You can get clipping on certain movies (very few) when using bass management if the volume is up all the way. If you use internal volume then you will almost never have any clipping since you probably won't be listening with the volume up all the way.

[Buckster]

mojave - thanks for the reply.  I think I now understand but I need to think about it more carefully as bass management/LFE is a nightmare. I think what you are saying - is :

(1) if you are not using internal bass management within JRiver - then you'd just need to set the physical gain on the subwoofer to +10dB (effectively)

(2) but if you use bass management within JRiver then this is accommodated for internally within JRiver - and you wouldn't need the gain on the Subwoofer

if this is the case - I think I see where my setup is different to the OP and why its an issue for me - but not for him   My AV amp, has a number of digital inputs, optical, coaxial etc, and rather uniquely a USB input (effectively it works as a soundcard) - as 8 channel PCM (7.1).  Whilst the amplifier applies EQ, delays etc to the USB input it assumes any processing of the LFE channel and its levels are done by the device outputting to it - therefore all channels are at 0dB, with no LFE correction.  If I was to set the physical Subwoofer controls to correct for this, for all the other inputs on my AV amp - for which the amplifier performs internal processing, the LFE levels would be wrong

So if I use the bass management in JRiver (as per the OP) and disable the bass management within my av amplifier - then the levels of the 8 channels, including the Subwoofer output (containing the LFE channel mixed with the cross-over bass) output from JRiver - should all be correct without any post-processing - fantastic

[mojave]

mojave - thanks for the reply.  I think I now understand but I need to think about it more carefully as bass management/LFE is a nightmare. I think what you are saying - is :

(1) if you are not using internal bass management within JRiver - then you'd just need to set the physical gain on the subwoofer to +10dB (effectively)

(2) but if you use bass management within JRiver then this is accommodated for internally within JRiver - and you wouldn't need the gain on the Subwoofer

I'm saying #1 for either with or without bass management. With bass management other channels are correctly mixed in  with the LFE, but the subwoofer still needs to be set 10 dB louder than the other channels.