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[Bert Quick]

I would be grateful to hear any comments or suggestions about how you would set up the following mains system. This is what I have been given to work with:

6 – JBL SRX 725
2 – Yorkville LS 1004
4 – Yorkville Maxim 1000 (subs)
10 – QSC PLX 3602
2 Yorkville AP 4040

Some options I am considering are:
1)   Set all amps Bridge Mono and dedicate 1 amp per cab, running the 725’s passive.
2)   Run the subs from an AP 4040 in bridge mono mode and the 725’s bi-amped from one channel of a 3602 stereo mode. And running the HF drivers from one channel of 3602 stereo mode.

Thoughts please…

[Thomas Le]

If you have the cabling, I'd go biamp so that way it bypasses the internal crossover, therefore making the drivers run more efficiently.

Curious, how are you deploying all 6 of the SRX 725's?

[Ray Aberle]

I would be grateful to hear any comments or suggestions about how you would set up the following mains system. This is what I have been given to work with:

6 – JBL SRX 725
2 – Yorkville LS 1004
4 – Yorkville Maxim 1000 (subs)
10 – QSC PLX 3602
2 Yorkville AP 4040

Some options I am considering are:
1)   Set all amps Bridge Mono and dedicate 1 amp per cab, running the 725’s passive.
2)   Run the subs from an AP 4040 in bridge mono mode and the 725’s bi-amped from one channel of a 3602 stereo mode. And running the HF drivers from one channel of 3602 stereo mode.

Thoughts please…

Do you have an external system processor to work with (DCX2496, DriveRack)? If so, try it both ways and see which one you like better. If you just have a basic analog crossover, I would start with running them passive.

Presuming that you are using the LS1004 for subs, but you parenthesized "subs" after the Maxim 1000s, which are full-range speakers. If you are really using those as subs, I would stop. If you are using them as mains, I would stop, because mixing and matching tops within a system doesn't always yield the desired results.

Try to keep things stereo, if possible.

725s have a wide coverage area; three per side will yield quite an area. Resist the urge to face them all forward.

If you have the cabling, I'd go biamp so that way it bypasses the internal crossover, therefore making the drivers run more efficiently.

Only if you have set up your external processing properly... If you don't, then it'll gain no improvement. The internal processor is a great place to start since it was developed by people who do this full time for a living (JBL).

-Ray

[Don Boomer]

Given the choice I would always recommend bi-amping.  If done correctly you will end up with more dynamic range, lower distortion (passive crossovers add a lot of unnecessary distortion) and increased driver protection.

[Bert Quick]

Do you have an external system processor to work with (DCX2496, DriveRack)? If so, try it both ways and see which one you like better. If you just have a basic analog crossover, I would start with running them passive.

Presuming that you are using the LS1004 for subs, but you parenthesized "subs" after the Maxim 1000s, which are full-range speakers. If you are really using those as subs, I would stop. If you are using them as mains, I would stop, because mixing and matching tops within a system doesn't always yield the desired results.

Try to keep things stereo, if possible.

725s have a wide coverage area; three per side will yield quite an area. Resist the urge to face them all forward.
Only if you have set up your external processing properly... If you don't, then it'll gain no improvement. The internal processor is a great place to start since it was developed by people who do this full time for a living (JBL).

-Ray

Ray, you are correct about the Maxim 1000's. I misspoke. They are actually Sub 1000's from the same time period as the Maxims. Yes, I have plenty of cabling and ad Driverack PA and the tunings from JBl for the SRX series. I think we will rarely use all 12 boxes together but my plan would be to splay the 725's. Always stereo. I guess I am trying to set this up to be flexible enough to accomodate 3 different size systems. I am leaning toward a set up that would include:

Amp Racks 1 & 2 - PLX 3602 Bridged for Sub 1
                         PLX 3602 Bridged for Sub 2
                         PLX 3602 Stereo-each channel driving 1 Low/Mids on 725 (for 725's 1 & 2)
                         PLX 3602 Stereo-each channel driving  1 HF 725  (for HF 725's 1 & 2)
One of these racks to include the driverack.

The third amp rack would be set up basically the same way only using the AP4040's for HF driver amps. All racks paneled to get in and out and stay stereo. I have some serious concerns about using a 3602 rated at around 725 watts at 8 ohms to drive the 75 watt HF drivers. Thanks to all for the responses.

[Jay Barracato]

Ray, you are correct about the Maxim 1000's. I misspoke. They are actually Sub 1000's from the same time period as the Maxims. Yes, I have plenty of cabling and ad Driverack PA and the tunings from JBl for the SRX series. I think we will rarely use all 12 boxes together but my plan would be to splay the 725's. Always stereo. I guess I am trying to set this up to be flexible enough to accomodate 3 different size systems. I am leaning toward a set up that would include:

Amp Racks 1 & 2 - PLX 3602 Bridged for Sub 1
                         PLX 3602 Bridged for Sub 2
                         PLX 3602 Stereo-each channel driving 1 Low/Mids on 725 (for 725's 1 & 2)
                         PLX 3602 Stereo-each channel driving  1 HF 725  (for HF 725's 1 & 2)
One of these racks to include the driverack.

The third amp rack would be set up basically the same way only using the AP4040's for HF driver amps. All racks paneled to get in and out and stay stereo. I have some serious concerns about using a 3602 rated at around 725 watts at 8 ohms to drive the 75 watt HF drivers. Thanks to all for the responses.

Bert,

If you want to squeeze the last bit of performance out of the boxes, then biamp may be the way to go. However, if you are looking for ways to break the system up for smaller shows, that implies you don't need the additional output, and I think the JBL passive crossover is fine.

Either way you go, I would not worry about the amp wattage. nothing says it has to put out that much energy just because it can. If you pay attention to how you set the input level of the driverack and the limiters you should be fine. I know plenty of companies that power everything off of the same sized amps.

[Bob Leonard]

I agree with you Jay. After years of using 725s both bi-amped and using the passive crossover I've found the internal passive to work just fine and with fewer problems or expense.

[duane massey]

I worked in a club for 4 years (musician and technician) that had 3 725's per side, each one powered by one channel of a 3602. DRPA + analog board. Took a little bit of tweaking on the EQ to get what the owner and I wanted to hear, but once I got it all set we never once hit clip lights on DRPA or amps, at ridiculously loud levels. Never even considered going three-way after getting the tweaking done, and I'm not a big JBL guy.

[eric lenasbunt]

I use the 715's and I have found no real benefit to bi-amping unless trying to achieve very high output.
My experience was the same on the old 722's as well. If you are power and SPL hungry bi amp helps, if you are in "normal" land like me 95-105db at mix as max volume then passive is fine and cheaper/easier to divide up.

[Spenser Hamilton]

I would be grateful to hear any comments or suggestions about how you would set up the following mains system. This is what I have been given to work with:

6 – JBL SRX 725
2 – Yorkville LS 1004
4 – Yorkville Maxim 1000 (subs)
10 – QSC PLX 3602
2 Yorkville AP 4040

Some options I am considering are:
1)   Set all amps Bridge Mono and dedicate 1 amp per cab, running the 725’s passive.
2)   Run the subs from an AP 4040 in bridge mono mode and the 725’s bi-amped from one channel of a 3602 stereo mode. And running the HF drivers from one channel of 3602 stereo mode.

Thoughts please…

We bi-amp our SRX cabs for the most part, but they do sound fine running the passive crossover. The 712 (imo) sounds better bi-amped, the rest of our cabs get bi-amped to meet rider requirements, and since our racks are already configured they go out that way even when there is no rider involved.

We did manage to cook a few crossover boards a few years back running passive, but that was 2 boards out of the 20+ cabs we own so could have very well been a defect. We have not have a single component failure since.

Try it, decide if the work you do is worth the extra amps.

[ProSoundWeb Community]