Hi, for wiring purposes i would like to route cables from main output to my qsc tops and from booth output right and left channel to my qsc 181 sub (I only have one sub). Is the booth output connected to the onboard eq? Thx
A) Bad idea. You’d be feeding both your sub and tops the same full range signal. In matched PA’s that usually means that either the sub has it’s own cross-over filter (so will only play the lows) but the tops won’t have low off filters, in which case they will also play those same low frequencies. The whole idea of a sub is to transfer some of that low end reproduction from the tops to the sub, freeing up power on the tops for the low-mids while still sounding balanced.
B) As most controllers have only channel EQ, the EQ would take place before the signal hits the master and booth bus and therefor the same sound would come out of booth and master, with the possible exception of mic sound (not out of booth to prevent feedback, can be solved by pressing the POST button if you DO want to hear yourself or someone else using the mic over the booth). Some controllers have an EXTRA EQ just to fine-tune the booth, this is clearly separate from the master sound (which generally has no overall EQ).
So, back to your questions. It helps to share with us what exactly you hope to get out of it. Using the EQ to filter lows to the sub (through booth) and the rest through master to the tops won’t work. Lots of reasons but just take my word for it . I am gonna assume that you would like separate level control over the sub from the DJ booth through the booth level knob. Unfortunately most PA’s with active speakers are usually rigged to have master sound go into sub and then link sub to top (lots less cabling!) and using the built-in crossover filter to separate the (sub)low and the rest. Sometimes the other way round, i.e. into the tops first then into the sub, depending on which holds the filter.
The best solution would then be to get an active sub-woofer crossover, take the master out from the controller to it’s input and then use the crossover outputs to power each speaker individually. This would give you the separate level (and cross-over frequency) control over both subs and tops.
Personally I start by setting my tops as well as my sub (I have only one) to 0dB. I then play some tracks that are relatively bass heavy on a level I expect to hit during the gig and listen to the balance between the lows and the rest. Then I will turn the sub level on the sub itself up or down to suit my need and matching the room acoustics. When I find the sweet spot, it’s set and forget for the rest of the night. In the rare case that the room acoustics change a lot when people are present and I feel an adjustment is needed (more or less sub) I walk over to the subs and just turn them up or down a bit. So I have no need for controlling sub level from the booth, but that is just me.
As usual my two cents.
Unity FTW Unity Gains For The Win I work at Sam Ash Music Pro Audio/DJ/Technology Dept.