Power amp? Peavey vs Ampeg..

Is this amp OK?
Message
Author
Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Power amp? Peavey vs Ampeg..

#1 Post by Lesknow »

Hey now! I'm looking to power up two J-array tops & two slim T39s for a simple pa system for block parties & whatever else is (hopefully) happening some time later this year...I do hope you're all well by the way, let me also say that...

So the tops would be 8Ω Beta 12As (250W) & the subs 8Ω BP102s (200W). I have two power amps already from different bass rigs & I'm trying to decide which would suit me better here - a first-gen Peavey IPR3000- non-dsp with a built-in 4th order LR crossover at 100Hz...or an old Ampeg SVP1500- no built-in crossover, but banana jacks! There was an updated version later with speakons, so this guy would be from the 80s or early 90s. But still works great. The ampeg is stable to 2Ω on each channel, I'm not clear about the peaveys, are they as well? Naturally I would rather have the amp coasting along.

They each express their output ratings differently & I'm having trouble figuring out if either is more suitable for this kinda deal. I understand I'll be using voltages to set it up finally, but I've forgotten some of this basic math down the years..is either one a better fit based on the numbers?

Peavey:
1,490W RMS at 2 ohms (both channels driven)
840W RMS at 4 ohms (both channels driven)
440W RMS at 8 ohms (both channels driven)

Ampeg:
Per channel, stereo mode
2 ch (20-20kHz) 8 ohms: 230W
2 ch (1kHz) 8 ohms: 280W
4 ohms: 425W
2 ohms: 560W
Mono mode
(20-20kHz) 16 ohms: 460W
(1kHz) 16 ohms: 520W
8 ohms: 850W
4 ohms: 1120W

With each cab being 8Ω, I'll end up with 4Ω per channel, correct?...5Ω for the two subs, call it 4Ω for our purposes, I'm easy.

The T39 plans detail a simple 150Hz crossover if I want to go that route, but is Peavey's 100Hz a better way to go? Happy to hear any opinions, math, you name it.

Cheers for getting through all that
xoxoxo
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Power amp? Peavey vs Ampeg..

#2 Post by Bruce Weldy »

I would use the crossover in the Peavey. Run in mono - one side for tops, the other for subs. You will definitely need a limiter for the sub channel as that amp is going to put out over 50 volts and the BP102s can't take that.

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."

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: Power amp? Peavey vs Ampeg..

#3 Post by Grant Bunter »

Bruce Weldy wrote: Tue Mar 16, 2021 3:40 pm I would use the crossover in the Peavey. Run in mono - one side for tops, the other for subs. You will definitely need a limiter for the sub channel as that amp is going to put out over 50 volts and the BP102s can't take that.
+1.
The BP102 8 ohm drivers can take a maximum voltage displacement limit of 35V.
BTW, the BP102 8 ohm is 200W rated in an open baffle, not in a horn sub.
In a horn sub, the BP102 8 ohm can only take a maximum of 153W

That would only leave around 7V as headroom if you were to use the Ampeg. While I have done something with an amp with similar specs in the past, if you're thinking you might turn up, you want some headroom.

+1 on the limiter as well. It's mandatory, so, you might and could also use all the DSP processing available in a used Driverack. That's Limiter, Graphic EQ, crossovers and RTA all in a 1RU space...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Re: Power amp? Peavey vs Ampeg..

#4 Post by Lesknow »

I appreciate the input, fellas. So. Out of curiosity, when they say 440W RMS at 8 ohms, both channels driven, do they mean 2x440, each channel being 8Ω, or is it less straightforward? I remember buying the Peavey knowing it was overkill for my needs at the time & knowing that's the right way to go. Again, I understand watts are only calculated from voltage anyway.
I used to get this stuff ))
Last edited by Lesknow on Tue Mar 16, 2021 8:18 pm, edited 1 time in total.
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Re: Power amp? Peavey vs Ampeg..

#5 Post by Lesknow »

It's funny, I've gone on to understand far bigger things & pushed out the easy stuff. I'm like Kelly Bundy hahah
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28619
Joined: Tue May 02, 2006 5:59 pm

Re: Power amp? Peavey vs Ampeg..

#6 Post by Bill Fitzmaurice »

Grant Bunter wrote: Tue Mar 16, 2021 7:14 pm BTW, the BP102 8 ohm is 200W rated in an open baffle, not in a horn sub.
In a horn sub, the BP102 8 ohm can only take a maximum of 153W
That 200w rating is thermal, not mechanical. The voltage limits we use are for thermal or mechanical, whichever is less. In a ported box the BP102 mechanical limit is 17v.

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: Power amp? Peavey vs Ampeg..

#7 Post by Grant Bunter »

Bill Fitzmaurice wrote: Tue Mar 16, 2021 9:50 pm
Grant Bunter wrote: Tue Mar 16, 2021 7:14 pm BTW, the BP102 8 ohm is 200W rated in an open baffle, not in a horn sub.
In a horn sub, the BP102 8 ohm can only take a maximum of 153W
That 200w rating is thermal, not mechanical. The voltage limits we use are for thermal or mechanical, whichever is less. In a ported box the BP102 mechanical limit is 17v.
Just to make sure I'm getting this right for future:
While the thermal limit for the BP102 is 40V (200W@8 ohms), the mechanical limit in a T39 is 35V(153W@8 ohms)?
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28619
Joined: Tue May 02, 2006 5:59 pm

Re: Power amp? Peavey vs Ampeg..

#8 Post by Bill Fitzmaurice »

That's correct. The mechanical limit is usually lower than the thermal limit, sometimes by a very wide margin. That's why you can't use the thermal limit to determine maximum voltage.

Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Re: Power amp? Peavey vs Ampeg..

#9 Post by Lesknow »

Bill Fitzmaurice wrote: Tue Mar 16, 2021 9:50 pm That 200w rating is thermal, not mechanical. The voltage limits we use are for thermal or mechanical, whichever is less. In a ported box the BP102 mechanical limit is 17v.
And would that equate to just 36W?? If I'm getting it.
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Power amp? Peavey vs Ampeg..

#10 Post by Bruce Weldy »

Lesknow wrote: Wed Mar 17, 2021 7:32 am
Bill Fitzmaurice wrote: Tue Mar 16, 2021 9:50 pm That 200w rating is thermal, not mechanical. The voltage limits we use are for thermal or mechanical, whichever is less. In a ported box the BP102 mechanical limit is 17v.
And would that equate to just 36W?? If I'm getting it.
That's correct. But, his example is that driver in a ported box. In the T39, it's still 35 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."

Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Re: Power amp? Peavey vs Ampeg..

#11 Post by Lesknow »

Absolutely, just testing myself with the math.
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Power amp? Peavey vs Ampeg..

#12 Post by Bruce Weldy »

Lesknow wrote: Wed Mar 17, 2021 8:47 am Absolutely, just testing myself with the math.
Well, you can worry over the math or just use this and save the time.....

http://www.sengpielaudio.com/calculator-ohm.htm

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."

Lesknow
Posts: 27
Joined: Thu Feb 18, 2021 11:15 am
Location: Toronto

Re: Power amp? Peavey vs Ampeg..

#13 Post by Lesknow »

Bookmarked, thanks
And everything is to the back with a little slack

2x 3012HO Jacks for bass
Autotuba

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Power amp? Peavey vs Ampeg..

#14 Post by Bruce Weldy »

Lesknow wrote: Wed Mar 17, 2021 10:25 am Bookmarked, thanks
I bookmarked it shortly after arriving at this forum over 10 years ago.... :mrgreen:

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."

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28619
Joined: Tue May 02, 2006 5:59 pm

Re: Power amp? Peavey vs Ampeg..

#15 Post by Bill Fitzmaurice »

I bookmarked it but can't find the bookmark amongst the hundred or so I have. :bash:

Post Reply