BillFitzmaurice.info

I have noticed that on my own system as well as the one i recently built for another DJ that the SLA Pro's seem to be outrunning the T-39's.Here's the set up:

Signal from DJ rig into a mixer (mine is Mackie,his is an Alto),mixer main signal allowed to play up to 0 DB,limiter kicks in at about 3db.Signal passed to dcx 2496,both inputs summed signal,no input filters used.
Subs hi passed at 45hz,48db LR,low passed at 92hz,24db LR on channel 1(subwoofer channel in mono mode) output
Tops hi passed at 100 hz,48 db LR,low passed at 18khz,24db LR on channel 5 (mid/hi channel in mono mode) output.
The Subs are limited to 50 volts,the tops are limited to 52 volts.
The subs limit was set with a 60 hz sine wave,the tops with a 1000 hz sine wave.
The amp is a QSC GX7.
While playing recorded music the subs amp channel was wide open,the tops amp channel was 3/4 open and was ALOT louder than the subs which weren't V plated,corner loaded or wall loaded but it was in a living room,sh*# should have been falling off the walls.I have learned that recorded music wont reach the same levels as the sine waves,the most i measured from the sub channel was 20 volts.Anybody familiar with this or have had a similar situation ?

My immediate thought is: Because the SLA pros are a line array they only drop off at a rate of 3dB/each doubling of distance, whereas the subs drop off at a rate of 6dB each doubling of distance.

That would explain nothing in a small room though.

On the mono sub output channel, increase input to + 3dB and see if that balances stuff up...

Post a picture of your RTA frequency response chart.

Bill Fitzmaurice wrote:Post a picture of your RTA frequency response chart.

I haven't RTA'd that system,i will soon,im expecting a DEQ 2496 from Leland to arrive tomorrow but also expecting rain.Shouldn't i RTA just the tops ?

djtrumptight wrote:Shouldn't i RTA just the tops ?

Sure, if you're only using the tops.

djtrumptight wrote:While playing recorded music the subs amp channel was wide open,the tops amp channel was 3/4 open and was ALOT louder than the subs which

Did you compensate for the difference in signal coming from the crossover?

You have one octave going into the subs, and 7 octaves going into the SLAs. That creates about a 6dB difference in signal level between those. Turn the tops down by 6dB and rerun the test.

http://www.prosoundweb.com/article/prop ... ucture/P8/

Bill Fitzmaurice wrote:

djtrumptight wrote:Shouldn't i RTA just the tops ?

Sure, if you're only using the tops.

I thought....i could have sworn......i was told....i think,to RTA 1 DR250 outside,alone,no subs ? I see a RTA session coming on.

thanks for the advice fella's,i will report back what happens.

"It was in a living room"

This is your issue. You had major cancellations going on.

In an open field I run my 4-t48s 10 db below my tops. Put me in a room or between two buildings (this past weekend) and I have to split my subs to try to counter this and run them a little hotter.

guitarkeys.com wrote:"It was in a living room"

This is your issue. You had major cancellations going on.

In an open field I run my 4-t48s 10 db below my tops. Put me in a room or between two buildings (this past weekend) and I have to split my subs to try to counter this and run them a little hotter.

According to Fed Ex my DEQ2496 for this rig will be here tomorrow so i will take the system outside,make the changes i was told to make and take a RTA reading.Thanks again for all input.