QSC 3102 or 3602 for 4x T48 subs?

Is this amp OK?
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dlv
Posts: 87
Joined: Sun Jun 09, 2024 6:39 pm
Location: Prescott AZ

QSC 3102 or 3602 for 4x T48 subs?

#1 Post by dlv »

I have the opportunity to buy some QSC PLX amps that are in decent condition. Haven't been on the road, perm install use. Seller has both 3102 and 3602. I'm thinking of picking up 2x3102s, one for subs, one for tops (DR250's I'll build later).

For subs I'm planning to build 24" T48's loaded with LAB-15 drivers. Those have 11.8mm xmax so nearly 60v to drive to full excursion based on what I got from the table in Bill's plans.

With two T48s a side (4 ohms) that appears to be at the rating of the 3102 (900 watts/ch) so I'm wondering if I'll be stressing that amp too much to drive 4 subs. It is rated down to 2 ohms (unbridged) so maybe that means it's got current headroom to be ok with running it there?

Am I thinking about this correctly? Would I be better off/safer with the 3602 or am I wasting $$ on it? Might be splitting hairs here but the cost difference on the amps is half of a driver so it's not entirely insignificant. I also read in Bill's plans that limiting to 50v won't have a significant impact on output. That's running the a 3102 at ~83% which will surely be better for it as well as giving some safety margin for the drivers.

Thoughts?

Thanks!

-Dave
Builds:
4 x 24" Titan 48's loaded with 15's
4 x OT-12's with CD horns
Considering:
Simplex 10/12 wedges
Simplex subs
Simplex bass/guitar cabs

Bruce Weldy
Posts: 8543
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: QSC 3102 or 3602 for 4x T48 subs?

#2 Post by Bruce Weldy »

dlv wrote: Wed Jun 12, 2024 1:13 pm I have the opportunity to buy some QSC PLX amps that are in decent condition. Haven't been on the road, perm install use. Seller has both 3102 and 3602. I'm thinking of picking up 2x3102s, one for subs, one for tops (DR250's I'll build later).

For subs I'm planning to build 24" T48's loaded with LAB-15 drivers. Those have 11.8mm xmax so nearly 60v to drive to full excursion based on what I got from the table in Bill's plans.

With two T48s a side (4 ohms) that appears to be at the rating of the 3102 (900 watts/ch) so I'm wondering if I'll be stressing that amp too much to drive 4 subs. It is rated down to 2 ohms (unbridged) so maybe that means it's got current headroom to be ok with running it there?

Am I thinking about this correctly? Would I be better off/safer with the 3602 or am I wasting $$ on it? Might be splitting hairs here but the cost difference on the amps is half of a driver so it's not entirely insignificant. I also read in Bill's plans that limiting to 50v won't have a significant impact on output. That's running the a 3102 at ~83% which will surely be better for it as well as giving some safety margin for the drivers.

Thoughts?

Thanks!

-Dave
Personally, I'd go with the 3602 if you are going to run 2 cabs per side. The extra headroom will keep it running cool.....but, the 3102 should be able to produce fine if you limit to 50 volts.

Why the Lab over the 3015LF? 3015 is lighter and cheaper with essentially the same output, especially if you limit to 50 volts.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

dlv
Posts: 87
Joined: Sun Jun 09, 2024 6:39 pm
Location: Prescott AZ

Re: QSC 3102 or 3602 for 4x T48 subs?

#3 Post by dlv »

Bruce Weldy wrote: Wed Jun 12, 2024 1:57 pm Why the Lab over the 3015LF? 3015 is lighter and cheaper with essentially the same output, especially if you limit to 50 volts.
Thanks Bruce. Well, you bring up a great point if I go with the 3601. It likely would make sense to do exactly as you say.

However if I did go with the 3602 I can run it up to 60v and then the difference (Vd 968cc/Xmax 11.8mm for the LAB-15 vs Vd 846cc/Xmax 9.6mm for the 3015) would have me wondering if there's really a material sacrifice there. I don't have the experience building these cabs or running anything like them to really know.

The cost difference is roughly $150 on the amp, $45x4 on the drivers so $330 on the whole project. My buy once, cry once gene is firing on that and telling me not to compromise.

I may have just talked myself into the 3602 either way. :lol:

Still, I get your point about weight and if anyone thinks I'm really not going to notice a difference in the drivers please keep the feedback coming!

Cheers,

-Dave
Builds:
4 x 24" Titan 48's loaded with 15's
4 x OT-12's with CD horns
Considering:
Simplex 10/12 wedges
Simplex subs
Simplex bass/guitar cabs

Bruce Weldy
Posts: 8543
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: QSC 3102 or 3602 for 4x T48 subs?

#4 Post by Bruce Weldy »

dlv wrote: Wed Jun 12, 2024 5:02 pm
Bruce Weldy wrote: Wed Jun 12, 2024 1:57 pm Why the Lab over the 3015LF? 3015 is lighter and cheaper with essentially the same output, especially if you limit to 50 volts.
Thanks Bruce. Well, you bring up a great point if I go with the 3601. It likely would make sense to do exactly as you say.

However if I did go with the 3602 I can run it up to 60v and then the difference (Vd 968cc/Xmax 11.8mm for the LAB-15 vs Vd 846cc/Xmax 9.6mm for the 3015) would have me wondering if there's really a material sacrifice there. I don't have the experience building these cabs or running anything like them to really know.

The cost difference is roughly $150 on the amp, $45x4 on the drivers so $330 on the whole project. My buy once, cry once gene is firing on that and telling me not to compromise.

I may have just talked myself into the 3602 either way. :lol:

Still, I get your point about weight and if anyone thinks I'm really not going to notice a difference in the drivers please keep the feedback coming!

Cheers,

-Dave
Sent you a PM

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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