SRX715s, Subs and QSC power amps

[Shovelhead]

I have a pair of JBL SRX715s, and a pair of 1x18 Subs that handle 800 watts RMS each (one Eminence Magnum Pro LF 8-ohm loaded into each reflex cab).

 

I've been putting together a little system over a period of time. I'm in no hurry because my band is using a nice JBL system that belongs to our bass player. I'm building this one with gig money for a future time that I'll need it. After all, NO band is permanent.

 

I have 2 QSC RMX2450s, and 2 QSC RMX1450 amps. The original thought was to power the tops with one RMX2450, and power the subs with the other RMX2450, and use the pair of RMX1450s for monitors. However, after looking at QSCs site, I wonder if there's a better alternative. They recommend a bridged RMX2450 for each box!. That spells new reconed drivers in my book, but I wonder if it'd make more sense to go for more power.

 

The style of music is classic to some new rock. No metal. Fairly loud, but not painful, in rooms that vary from 100 to 200 or so.

 

Given the amps, would you:

 

1. Leave it alone and run it conservatively by powering each box with one channel of the RMX2450 (500 watts RMS). Use the RMX1450s for monitors.

 

2. Run each top with an RMX1450 in bridged mode. Each side would see 900 watts at 8 ohms. Buy another RMX1450 and run both subs with one bridged RMX1450. Total ohms would be 4, and the amp would deliver 700 watts to each sub. Use the RMX2450s for monitors.

 

3. Run each top with an RMX1450 in bridged mode. Each side would see 900 watts at 8 ohms. Run the subs with a bridged RMX2450. Each sub would get 1200 watts. Buy another RMX2450 and use 2 for monitors. I'd have to be careful on the low end with this arrangement.

 

4. Something different, but somewhat budget friendly?

[agedhorse]

Power conservatively as you planned.

 

The QSC recommendations are, IMO, a conflict of interest as they are trying to sell more and bigger amps.

 

QSC powers their own powered speakers at close to the RMS or continuous rating of the drivers. IMO, do as they do, not as their advertising's hired mouths say.

[Shovelhead]

 

Power conservatively as you planned. The QSC recommendations are, IMO, a conflict of interest as they are trying to sell more and bigger amps. QSC powers their own powered speakers at close to the RMS or continuous rating of the drivers. IMO, do as they do, not as their advertising's hired mouths say.

 

 

Thank you.

 

The RMS rating of the tops are 800 watts, and the bottoms are 800 watts. Would you recommend option 1 or 2?

[RoadRanger]

I'd start with #1 - see if it works out for you (good for about 150 people). You really need another pair of them subs to match the output of them tops (good for about 300 people).

[drumstix]

For 1-200 people the 500w per channel would probably be ok. JBL recommends 800w and some will double that. My band played in a small venue that would seat about 150 and they had a pair of the 715's flown, they sounded great and had plenty of volume but to my surprise was just how little of a amp they were using on them. Something like the RMX1450, or the 850....cant remember right now. Regardless less than 500w.

 

I would use the 2450 unless you can find a good deal on a used amp like a PLX3402, XT14000. The PLX are on ebay for around $650.00 or so.

[agedhorse]

Start w/ option 1 and if needed graduate to option 2.

 

Most folks don't realize how much is lost due to power compression as the power levels increase. It can be as much as 50% of any theoretical gain is lost.

[Shovelhead]

 

Start w/ option 1 and if needed graduate to option 2. Most folks don't realize how much is lost due to power compression as the power levels increase. It can be as much as 50% of any theoretical gain is lost.

 

 

Thanks so much.

 

I'll start there, but will keep my eye out for a killer deal on an amp, and snatch one up for when I'm ready to move up.

[Unalaska]

You could bridge a 1450 into pair of 715's and the same for the subs? It does drive them harder though and a better long term solution would be a 3402 in stereo.

[scottc]

I dont think some of us realize that sometimes it dosent take alot of power to play a venue and I think alot of the pro sound guys will say at times power/wattage is not the answer more coverage is the answer. Anyway, example of a place we play that holds 300-500,we roll in with 8000-10000 watts of power, we dont use all of that, but another band that plays at the same place goes in with a 1200watt powered mixer for 4-15" mains,2-powered 15" mackie subs and do the same job we do, volume and coverage is great. I used to bridge some of my amps, now they all run in stereo mode.

And when someone walks up and says,"turn it up", if your near the max,dont turn up,walk over to your board and simulate turning things up.In reality if its not loud enough go back next time with more equipment.

Just my 2 cents worth.