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[MarcVRML]

I've noticed this problem on every version of MC I've used, where audio playback for multichannel tracks is actually 5db lower than the volume level I get in Adobe Audition.

Groove and Audition both demonstrate the same gain in playback, when compared to MC29. But more importantly, to my ear it sounds like the loss of that 5db has also removed some punch and attack from the music which increasing the volume on my external amp doesn't restore.

FYI I'm not using volume correction or adaptive volume, and the problem seems to be limited to multichannel audio which I've ripped losslessly to FLAC.

If I open the track in Audition, playback is just fine with great dynamic range (as you'd expect from an editing tool) and no peaking.

The same track played in MC29 or previous versions is -5db down.

2-channel audio however is not, which means that for any multichannel track, I need to nudge my amplifier up a few notches.

I've tried using Flex ASIO, WASAPI, DirectSound, et al, have verified the volume controls (including windows mixer) are maxed.

I've performed MC's audio analysis but as stated I'm not using any form of volume correction.

I've also tried this with and without the JRSS mixer active, as well as using various different Windows audio settings from simple 2 channel stereo up to 7.1 and Atmos. Same result each time.

It's as if playback is being limited for multichannel audio, in a way that doesn't happen for stereo.

I understand that there is inherent headroom applied for additional audio processing within the MC algorithm but to be frank, this is driving me nuts!

I've attached a log and a pic of the audio path.

Any ideas? Or is this fixed in MC30?

Thanks!!

[mattkhan]

No pic attached?

[MarcVRML]

Hi Matt, sorry - pic attached to this reply.

Also, more info - I've been able to isolate the root cause :
I use DSP Studio set to :
Output Encoding : None
Sample Rate : (everything changed to 48Khz except 48Khz source material which is listed as "no change")
Channels : 7.1
Extra Channels : None
Mixing : JRSS Mixing (recommended)
For Stereo Sources, only mix to 2.1 : OFF
Move center to front L/R : OFF
Detect stereo sources in surround : ON
Subwoofer : Silent (use room correction to redirect bass to sw)

With the above setup, feeding the system 6-channel FLAC audio results in the 5db drop.

However, when I switch to the following settings, the problem immediately goes away and I'm up to full volume, undistorted again ...
Channels : Source Number of Channels

However, whilst this sounds terrific, it completely removes all the benefits for my other 2-channel music of the JRSS mixing, which does an awesome job of upmixing to 7.1 (which is the native number of channels I operate on my Windows system).

I've also confirmed that the 5db dip occurs in 2-channel audio as well, as long as the output channels are set to 7.1. As soon as they're set to "source number of channels", volume shoots up and dynamics feel great.

Hope that helps!

Best,

Marc

[Matt]

Would you be willing to try the latest MC30 and see if the problem is still there?  Thanks.

[MarcVRML]

I'd be happy to if you could arrange for an upgrade?

[mattkhan]

I think @Matt would have to explain exactly how 5.1 is upmixed to 7.1 however how do you think it should be upmixed? simply clone them? something else?

However, whilst this sounds terrific, it completely removes all the benefits for my other 2-channel music of the JRSS mixing, which does an awesome job of upmixing to 7.1 (which is the native number of channels I operate on my Windows system).

you can always use zoneswitch to apply DSP differently to different mixes

[MarcVRML]

That's a really good point - I've just tested after setting the Channels to 5.1 with JRSS both enabled and disabled, and in both cases volume and dynamics were great. As soon as I switched to 7.1, that's when the 5db attenuation occurred.

It's like there's a deliberate overhead in the upmixer which drops the audio levels.

Best,

Marc

[mattkhan]

It's like there's a deliberate overhead in the upmixer which drops the audio levels.

from what I can see, JRSS 5.1->7.1 knocks RL/RR down by 3dB and then puts something (a copy of RL/RR?) in SL/SR about 9dB further down. LRC and SW are untouched. This doesn't seem like it would account for a 5dB drop overall, I think it could change the surrounds quite a bit though depending on your layout.

[MarcVRML]

I'm measuring the 5db drop on L/C/R, which is what makes it so noticeable.

[MarcVRML]

If anyone's monitoring this for answers, I have some more info (and I'm kicking myself it's this obvious).

It turns out that although my system is natively 7.1, when activating Dolby Access for Atmos audio, it applies 5.1.4 instead of 7.1.4. This may just be a glitch on my system, but it seems that the loss of the additional 5db I measured is as a result of those extra 2 channels going missing. Once I drop the output format to 5.1 instead of 7.1, full audio volume returns on all content, regardless of whether I use JRSS upmixing or not.

Thanks to everyone who tried to assist.

Best,

Marc