Downmixed to mono- freq imbalance?


2014-06-22 6:45 am
I just got done building one channel of my monoblock and have been listening to both of my speakers fed from that with mono mixes. And i find that native mono mixes (from youtube) sounds excellent.

But some music downmixed to mono (either digitaly or with a switch) sounds horrible. The frequency balance is way off. So much so that it makes the amp sound as tho its broken.

Why is there such a discrepency and whats the science of it?

Thanks and regards
Maybe its not frequency balance? but comb filtering, phasing and such, there is no hearing system making filtering since it all is mixed in electric domain and output by single source.

Many "stereo tricks" in mixing exploit hearing system. For example, take mono track and add very short delay to it both, pan them both to different sides and hearing system perceives it nice "widening" effect. Mix them in mono and listen and now instead of widening there is this nasty comb filtering. Also many stereo mic techniques don't work too well in mono, stuff thats got "bleed", recorded live and miced so that instruments coming through other instruments mic can also make very nice sound in stereo but might have phasey sound to it when mixed in mono and listened from one speaker.

You have two speaker mono, not sure if this is much different than single source mono. Important thing here is that hearing system cannot do its thing, which the recording/mixing engineer probably relied on.

I've been in single speaker mono for long time and have used to it, its not too bad I think. Jazz sounds fine, most old stuff sounds just fine, electronic dance music seems to sound fine. Some pop stuff sounds bad, no life to it but not sure if its mono/stereo issue :D Perhaps I'm so used to it I don't know the difference anymore.
When you say with a switch are you buffering the L/R feeds or just shorting them together? Shorting even from a pre amp can cause all sorts issues, you need a resistive mix. Also as tmuikki says many stereo recordings are enhanced with phase effects which will cause frequently cancellations when added together. It's likely the YouTube mixes you are listening to are original mono recordings. If you want to use familiar tracks for testing pick those which have a strong central image and listen to just left or right until you have the second amp up and running.