Pre-amp

This subject has been posted on speaker plans as some of you will have seen, so I'm asking the same question here. Mono or stereo? After my gig on Friday night, I was left feeling that things could be even better in stereo, which obviously reflects on the "preamp" mixers that are used. I'm trying to gauge the general feeling on the subject.

for me i think stereo, the only thing i would run in mono is sub base. All music in this day and age is recorded in stereo, even the the tunes made in bedrooms, why would we then run it in mono, and loose some of the quality......... for live acts i.e. bands then im not too sure as i dont have the knowledge in this kind of setup........ Most digital equipment runs in stereo, i cant see the need or the gain by running it in mono.....

I understand why roots systems use a preamp, so they can adjust the sound to there system. But can a preamp control a system as well as a BSS, dbx or ultradrive. Ive seen and listened to roots systems where no delay was added for example to the horns, for me this was a waste of energy and the system would of performed better with delay, and stacks run in mono...... for older tunes pre 70's yes there will be no differance in mono or stereo, mono probably being better. But on current tunes etc stereo wins........ what was the choice of material Tony, cd's, wax or mp3's........

there's no reason why you can't run outputs of a pre into an LMS to sort out delays...?

Gee136 gave a pretty good case as to why mono is used by soundsytems over on SP.

midtops only for me - it would be nice i guess. pretty pointless in a single stack, but with 2 or 3 stacks in a venue, it would be wwwiiiiicccked.

The material was mostly Vinyl and CD when the PA was on. I'm genuinly intrigued at the moment with the whole Mixer situation. I'm just suspisious that the whole Pre-amp thing is being over stated in it's role within the speaker system. What are you to think if someone says at a dub gig that it's the best sound they've ever heard and then realize that everything went through a 388 omnidrive?

i read gee's post but read it to by why a pre amp is used, not why should we or should not use a stereo run system....... there is stereo pre amps, why don't people opt for these, rather than mono ones..... why feeling is yes there are gains from a pre amp, but i think the system should be run in stereo....... why play a stereo mixed track and convert it to mono, surely this is detrimental to the sound...... Is it an issue of the sound systems as a hole not wanting to go forward with new ideas...........

I had a read of the Preamp thread on Speakerplans and I can see the attraction of using a custom preamp
that is used to shape the sound. These custom preamps seem to be made with audio quality in mind. Compared with the normal crap stuff that you find in your average 'pro'-consumer grade unit. a decent preamp probably blows it away in audio quality.
We know that eq's can kill audio quality but when it is used creatively by a performer thats OK by me.
If mono is part of the perfomance sound then why not!
Mono has certain advantages - Feedback rejection is different with vinyl used in mono.
Eq in mono will always have a coherent phase. Stereo eq adds the complication of trying to get the 2 channels to exactly match.
What I don't agree with is the use of separate crossover frequency outs to drive the active rig. In these days of advanced speaker management systems it seems old school to do this.
By all means filter the sound into musical frequency bands. Kill cut shape them to suit but then sum them back to a single output to feed thru to the PA system.

i think you'll find most pre's have a full range output to do exactly this anyway

should a shame to introduce the delay settings on a pre? I mean directly on circuit without introduce lms or post processing stuff in the chain.

You won't be introducing delay of any kind unless the preamp is digital. I can't see that happening in the near future.

sorry but why? Analogue xover can delay, yes should be useless if you use just reflex or sealed cab.. but I think is the truly useful feature (from a cab designer point of view ) that a preamp miss in these days.