mono sum in the control room? (solved)

So, has anyone noticed that the mono sum delivers a VERY different level and image than summing to mono in the analog world? I have now tried two different analog monitor sections’ mono switch–the two analog sound roughly the same (at least as much the same as the stereo sound!)…but, using the Cubase Control Room mono switch is crazy different. The bass (panned right up the middle) goes way down. Huh? In a mono sum, that should go way UP, depending on the amount of cancelation elsewhere…never down–it’s right up the middle.

I can’t find any config for it, like I have something set oddly…advice?

I’ve got these units determining whether I should use them, or just configure a controller for the control room…

Ok…so someone else noticed…yet no one has an answer?

If there’s nothing misconfigured (like maybe there’s a surround kind of HPF configuration for the “collapse” somewhere I can’t find)…I can assure you the analog mono sum is “right”. The bass and kick are panned dead up the middle–which would make for NO cancelation…and yet, this control room mono sum is bass deficient…should be likely the opposite.

Yeah, I kind of agree with you, I exclusively use my “physical” mono summing

yep i’ve noticed this too…
could do with some proper investigation!

Yeah…of the two I’ve tested–one is on theAkai recorder I need to phase out…and one is the Radial that sounds like a$$ otherwise. I’m habing a hard time thinking I will actually have to pay $1300 for a DBox or $1k for a DAC w/stepped attentuator…just to have a decent monitor control.

Ironically, mono sum was the one feature I thought would be exactly the same in the Control Room. If anything, the lack of crosstalk might make it a truer mono sum…

Anyway–no one knows of any LFE/Surround configs that might be affecting it? I’ll give it this last bump…then I’ll just give up and know I have to go analog with the new system.

Can you do a test, two sine waves one polarity reversed panned hard L/R, then switch to mono, should cancel.

You could try various frequency from very low to high.

Compare software mono sum and hardware mono.

Done. Neither cancel. Unless I did something wrong…two mono tracks, pan one L one R, reverse the phase on one…insert test tone generator, set for same frequencies, try both mono collapse methods (third analog one is no longer hooked up)…anyway-doesn’t cancel. Tried 100hz, 500hz, 5k, 15k.

Also tried the same with white noise. Nope. It canceled the most…but, not even close to null, grand scheme. They did seem relatively the same in this test. Obviously hard to judge whether one cancelled a little more than another–it’s test tones…but, if they did, it didn’t seem drastic.

Side note…I’m a little proud of myself…I could hear the tone right up to north of 19khz…I guess earplugs at concerts my whole life has been effective.

Try using a recorded mono tone or mono white noise, Duplicate it, pan original left, then invert the duplicate and pan right , then null test. Generators are just too random for real time null tests.


I’ll give it a go when I get some time.

No, like Hippo said, you need an exact copy of the audio on the left to be phase inversed on the right. Not a test tone generator on each side - they won’t be synchronised.

FWIW works exactly as expected in C 5.1.

Ok, so this issue was bugging me so I poped out to the studio and set up some null tests. Well the results were as expected, perfect cancellation. But… I could still hear a difference between my hardware summing and software summing (to mono)? So I played around with the mix convert window for a while. Now I really don’t know just what happened but with everything back to its default settings I now get proper mono software summing and sounds, as far as my ears tell me, exactly the same as the hardware summing? Very odd indeed!!!

Just switched the pooter off and on (hard switch off) and It’s still good !!!

Insert the test generator on an input - then select this as the source for the two tracks.

I know how to do null tests!

Further investigation of the MixConvert plugin for the Control room downmixing may suggest that the norm button for the center speaker may be on by default for some people causing a drop in level when switching to mono?

Is this a standard plugin in the Control Room? (sorry, I don’t use CR)

Yes, it’s always on as it were! For most people it is hidden and unknown about, but its function is to convert various surround formats to other speaker configs. Mostly if not using surround it converts stereo to mono when the mono button is pressed.