I'm sure I have misunderstood the concept of dual mono, so I would love if someone can explain a thing or two for me:

I have a Shadow Hills Vandergrah in my 500-rack - which is a stereo compressor (not dual mono).

Since it is not dual mono I have just assumed that weird things will happen when sending two separate mono-tracks to it.

But when I sent a stereo-stem through a pair of mono-preamps (slot 5 and 6), and then into each side of the compressor (slot 7 and 8) - it sounded all fine?

Is it supposed to sound fine? I couldn't hear anything weird. Would it have sounded different if it was a dual mono stereo compressor? Have I just misunderstood the concept of dual mono?

Sending a stereo source through two mono preamps is still stereo.
On an stereo compressor the channels are linked (processing both channels the same), with an dual mono compressor the two channels are processed separately.

Dual Mono = 2 discrete channels of audio, but both channels are getting the exact same source.

For example, most people are listening on a sound system that is stereo. Stereo meaning 2 discrete channels of audio. A Left speaker and a Right speaker...Or a left headphone and a Right headphone.

When you take a mono signal (one channel of audio) like a vocal you recorded and play it through a stereo playback system (2 channels) and leave that vocal panned to the "center" that simply means it is in dual mono. Equally sent to the left and the right.

Perhaps understanding better what the term dual mono means will help you understand how the processing of stereo and mono signals through stereo and mono devices works.

Well it sounded fine because it was a stereo stem to begin with.

but in your specific case, those "two separate mono tracks" were the right and left sides of a stereo stem! In the ITB world, we see 'stereo' tracks, but they are just a fiction. Stereo tracks are just a right and a left that are ganged together for convenience sake.

If you had sent a (mono) snare drum to the left channel and a (mono) bass guitar to the right, in your stereo compressor, I bet you would have heard some weirdness.

At the very least, the detectors in dual mono compressors CAN be unlinked. Here is what would happen: Suppose someone hit a conga panned to the right channel. There would be a peak detected on the right, and the right channel (only) would compress, lowering the volume of everything in that channel. Sounds that were panned to the center might seem to shift the other way, because center sounds are put into both channels 'equally' and now with one side compressing, they are no longer equal. This may not be very drastic at all, though.


It looks like you have only one set of controls for both channels on that unit. You could not put the left channel at 2:1 and the right channel at 10:1 even if you wanted to. I would say the way you just used your stereo compressor for a stereo stem would be the 'normal' way of doing it. In a stereo compressor, the detectors are linked - a peak on either the right or the left detector will start compression on both channels. Keeping the center image steady.

If it was the other way around - if you were feeding this stereo mix into a dual mono compressor, often you won't hear a huge difference other than some 'wobble' in the center image. Not the end of the world, and some folks prefer that sound and intentionally unlink their stereo compressors.

But usually dual mono units can also act as two completely independent compressors - meaning you could do snare in one channel and bass guitar in the other. Unlink everything. Set ratios, attacks, releases etc. independently.

Many plugin compressors have a way to link or unlink so you could use one of those to experiment and get an idea of what the sound difference is like.

Aha - it all makes sense now.

Thank you all for clearing that up - it took some time to wrap my head around the concept. I am super happy that the compressor is still useable for my needs!

Remove this bot ^

Where is the moderation to stop this stuff