HELP! How would you use 2 crown xls and 2 peavey IPR's

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Dan56
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HELP! How would you use 2 crown xls and 2 peavey IPR's

#1 Post by Dan56 »

I got to do my first gig with the full rig today. 2 T39's (28" and glad I built them this wide) and 2 )T12's. I was running 4 monitor sends. I have the following amps: Crown 402, Crown 802, Peavey IPR 1600, Peavey IPR 3000.

When I first did the limiting, I used the 3000 on the subs but was butting up against the IPR's protection (these are not the DPS models, they are 1st gen versions). It would roll back the voltage to 48V as I tried to limit at 55v. So, I've been running the subs with the Crown 802, stereo fed.

Today, I ran the subs with the 802, the tops with the IPR3000 and the monitors with the 402 and 1600. I had 3 circuits to run the whole band so the amps were on one with the board and rack. I did run 2 separate 12 gage lines from the one outlet in the building to try to give some relief. The other 2 circuits were running 2 guitar, bass, leslie and effects, key boards.

At one point during the show, I got a noise from the IRP 1600, simply unplugging the monitor and restarting the amp fixed it. But the bigger problem was 1/2 through I'm a Man the IPR3000 stopped putting out. At this point we had 1 more song to do so I switched off 2 monitors and put the OT12's off the Crown 402.

Now, I have another outing this next weekend with 2 bands Friday and my band Saturday.

So, a couple things, how do you run the power to your amps? if I only have 3 circuits do I need to reconsider how many amps I'm running. I have been running stereo but certainly think I need to rethink this. With the newly acquired A & H board, mono out is present.

What about power conditioners and all that. I have no knowledge of them or anything related to devices for effecting the power to the amps.

Other than that, it was sounding very good. 1/4 mile down the parking lot on the right side. On the left I had a 5 story brick wall of the school building about 150' away. Made for some odd experiences as you walked around.

Grant Bunter
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#2 Post by Grant Bunter »

You have to go back and work out your power draw.
Dig into manuals.
You might need to get onto support at Harman.
I've tried to find power draw with the 402 and 802's, but that spec isn't in the data sheets.
You have to remember that 10% or 30% draw figures etc are useless when you're running full tilt.

For example, the 402 does 450W/4ohms, or 42V.
If your putting out 38V or above using that amp, then your draw is almost 100%

Standard outlets here are 10A @240V, or 2400W.
Finding three different cicuits is well done on your behalf, did you check they all had only 10A breakers (this is likely if they had 10A outlets)?
Using different circuits for PA amps and mixer to spread the load more is ok, as long as they have the same ground.
Otherwise you will introduce ground loop hum.

I would free up one of the circuits by running all the bass and guitar amps and keys etc on only one circuit.
Then put one each of the most powerful, and least powerful amps on each of the two remaining circuits.

I know your were probably trying to limp through the gig and get it done, but did you see why each amp failed?
Like protect mode, or DDT or Thermal shutdown???

Other than that, any reason for 4 monitor sends?
Can you not pair up any sends.

And running mono is fine for live work (I run live music and DJ in mono). The only exception being the bands heavily rely on stereo imaging for hard panning effects...
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...

Dan56
Posts: 164
Joined: Tue Feb 11, 2014 10:44 pm

Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#3 Post by Dan56 »

Grant Bunter wrote:You have to go back and work out your power draw.

For example, the 402 does 450W/4ohms, or 42V.
If your putting out 38V or above using that amp, then your draw is almost 100%

Standard outlets here are 10A @240V, or 2400W.
Finding three different cicuits is well done on your behalf, did you check they all had only 10A breakers (this is likely if they had 10A outlets)?
Using different circuits for PA amps and mixer to spread the load more is ok, as long as they have the same ground.
Otherwise you will introduce ground loop hum.

I would free up one of the circuits by running all the bass and guitar amps and keys etc on only one circuit.
Then put one each of the most powerful, and least powerful amps on each of the two remaining circuits.

I know your were probably trying to limp through the gig and get it done, but did you see why each amp failed?
Like protect mode, or DDT or Thermal shutdown???

Other than that, any reason for 4 monitor sends?
Can you not pair up any sends.

All amps were running 8 ohm loads (1 speaker each side). The main faders were below 0 set so I was not driving too hard at all.

Standard breaker load here is 15 amps , 120v. I believe these were 20 amps. I was running the whole PA (board, rack, amps) off one circuit so no loops. No noise at all actually. Everything else ran off the other 2 circuits.

Unfortunately, I did not notice any lights on the IPR's. Frankly I did not think to look at them at the time. I just wanted to get the tops back, thus the quick switch. The only other thing I remember was that one side was weak for a bit when we started back for the final set, then it seemed to kick in and everything was sounding fine for about 3 songs. Then both sides of the 3000 stopped.

I have to say, trying to perform and run such a system (usually use 2 feeds for ear monitors only) with a new to me board...my mind was spinning all show. I had a weird monitor feed issue ( I think do to one of the EQs another item new to my use), the drummer showed up way late because he forgot and this was the show I was trying mic'ing his drums individually (because the next gigs are under a tent it rings like crazy) so no time to do a good job there. The bass player was getting nervous because we were 1/2 hr late already. You know how it goes.

Running four monitor feeds only because the headline band this coming Friday runs 4. The drummer in our band also plays in this other band. Their main sound person is running the main stage so I was asked if they could use our system on this second stage. I used today to see if I could get it setup correctly and that everything would run properly. Oh well....

And this was all done as a freebie for a good cause today. :)

Grant Bunter
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#4 Post by Grant Bunter »

So you guys have 1800W of available draw per circuit.

Fair enough on the 4 sends then.
And yeah, it would be handy to know what happened amp wise...
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...

NukePooch
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#5 Post by NukePooch »

According to this:
http://www.crownaudio.com/media/pdf/amps/139718.pdf

The 402 and 802 are pulling just over 15 amps combined with 1/3 power pink noise.

I could only find specs for the IPR2 series, not the IPR series, but I'd imagine you could pull well over 20 amps with everything at full tilt (not counting spikes).

I know the Crowns are front to back cooling...couldn't find info on it, but I'm thinking the Peaveys are back to front? Are they in the same rack?
Built:
4 Jack 112L- 3012HO, melded array
17.5 wide AutoTuba with Infinity 860w
6 Wedgehorn W6 w/ Panel Mount Piezos
2 T48 Slims (15" wide) with 3012LF
4 T48 Fattys (32" wide) with 3015LF

Grant Bunter
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#6 Post by Grant Bunter »

NukePooch wrote:According to this:
http://www.crownaudio.com/media/pdf/amps/139718.pdf
Given a doubling in amperage draw from just 0.125% to 0.33%, I'm thinking all amps at full tilt on one circuit drawing 20A would be conservative.

I think it would be fairly easy to say, you ran outta juice...
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...

Dan56
Posts: 164
Joined: Tue Feb 11, 2014 10:44 pm

Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#7 Post by Dan56 »

NukePooch wrote:According to this:
http://www.crownaudio.com/media/pdf/amps/139718.pdf

The 402 and 802 are pulling just over 15 amps combined with 1/3 power pink noise.

I could only find specs for the IPR2 series, not the IPR series, but I'd imagine you could pull well over 20 amps with everything at full tilt (not counting spikes).

I know the Crowns are front to back cooling...couldn't find info on it, but I'm thinking the Peaveys are back to front? Are they in the same rack?
The cooling flow was suggested by Bruce also. I will be checking that this evening. They are all in one 8U case, Crowns on bottom, Peaveys on top. I knew air had to flow, but never thought about amps having different directions. One more thing I have learned.

Dan56
Posts: 164
Joined: Tue Feb 11, 2014 10:44 pm

Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#8 Post by Dan56 »

Grant Bunter wrote:
NukePooch wrote:According to this:
http://www.crownaudio.com/media/pdf/amps/139718.pdf
Given a doubling in amperage draw from just 0.125% to 0.33%, I'm thinking all amps at full tilt on one circuit drawing 20A would be conservative.

I think it would be fairly easy to say, you ran outta juice...
It may also be that mixing the Crowns with the Peavey's regarding powering them is a no - no also. I have been informed that 3 similar amps have run successfully on 1, 15 amp circuit. If mixing them is an issue, then that becomes an issue overall because I have never had in easy reach 4 circuits to plug into. I always work to get 3. I have run the old setup off of 2 (only 2 amp for the system with IEM).

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dswpro
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#9 Post by dswpro »

Sounds like you have a defective IPR3000 or perhaps it is overheating.
I run an IPR3000 on 4x T39s regularly and another on 4x Otop 12s with nary a problem. ( they are the non-dsp versions ) One of my IPRs does have a slightly audible whine, presumably from the switching power supply. I use that for my subs. I also run a crown XLS1500 for monitors all on the same 20 amp 120v circuit. I'm not amplifying EDM, I mostly do live music. I also have a DEQ2496 and DCX2496 in the same rack and the DEQ will overheat on a hot sunny day unless I use an external fan on it.

Don Sullivan

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BrentEvans
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#10 Post by BrentEvans »

Grant Bunter wrote:You have to go back and work out your power draw.

You have to remember that 10% or 30% draw figures etc are useless when you're running full tilt.
This is something we see quite often here, and it's not entirely untrue, but it is two-dimensional thinking. With power amps, the amount of current drawn from the outlet is not as simple as a voltage and impedance calculation of the output. Amp power is rated based on either sine or pink noise, both of which are a constant voltage output. Most program content isn't sine waves. Your sub feed comes closest, especially with electronic music, so it's good to arrange sub amps based on their fuse rated current draw. For amps pushing tops and monitors, the actual current draw is much less becasue program content is so dynamic. I can run my entire system with 1 IPR3000 on subs at 4 ohms per channel, 1 IPR3000 for mids at 4 ohms, 1 IPR1600 for highs at 8 ohms, and 1 each of IPR3000 and IPR1600 for monitors at 8 ohms per channel, while also running my SAC rig (which draws 5 amps in and of itself) plus 8 sennheiser wireless recievers and antenna distros for that (1-2 amps IIRC) all on a 20 amp circuit and push FOH until all the DDT lights are lighting up and monitors so loud your ears bleed and not trip breakers. Bear in mind that I do music with good dynamic range, and then speech (church services) but the amps are "full tilt" as it were with 4 ohm loads on two of them.

The more compressed your program content is, the more dense in frequency it is, the more current the amps will draw at their max output. If I do something that's a little heavier, or requires all 8 of my IPRs I'll split it up into 2 circuits. I've NEVER blown a breaker, and these amps run into DDT way more than I like... but my program content means the breakers don't blow.

Now, take that for what its worth. Just realize that doing calculations based on amp fuses and ohm's law and breaker ratings is very nearly always going to leave you with power left over on each circuit, because there is a third dimension involved. We all know that wattage is the "area under the curve" on a chart, but we forget that it's really more like "volume under the plane" when dealing with amps, becasue frequency is also a variable.
99% of the time, things that aren't already being done aren't being done because they don't work. The other 1% is split evenly between fools and geniuses.

Dan56
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#11 Post by Dan56 »

BrentEvans wrote:
I can run my entire system with 1 IPR3000 on subs at 4 ohms per channel, 1 IPR3000 for mids at 4 ohms, 1 IPR1600 for highs at 8 ohms, and 1 each of IPR3000 and IPR1600 for monitors at 8 ohms per channel, while also running my SAC rig (which draws 5 amps in and of itself) plus 8 sennheiser wireless recievers and antenna distros for that (1-2 amps IIRC) all on a 20 amp circuit and push FOH until all the DDT lights are lighting up and monitors so loud your ears bleed and not trip breakers. Bear in mind that I do music with good dynamic range, and then speech (church services) but the amps are "full tilt" as it were with 4 ohm loads on two of them.
Thanks Brent. At least I have an idea of limits now. I understood that music is not steady and thus the draw is not necessarily at full boogie. But, I'm still quite new with sound at this level of operation so I'm relying on all the help I get here. (Thank you all)

I think it may be an over heat issue do to the mixed amps in one case. At the same time, I had not run this particular amp for long until yesterday. In practice I had used the 1600 for the tops and the Crown 802 for the bottoms with no issues. I have separated out the amps this afternoon anyway. I opened up the 3000 and it was quite clean inside, but I vacuumed and blew it out anyway along with cleaning the fan.

Dan56
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#12 Post by Dan56 »

I have just had it confirmed at the Peavey forum, the air flow on the IPR is back to front. So, maybe this was the issue having mixed air flow in the case.

Dan56
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#13 Post by Dan56 »

I just finished checking the system and the 3000 is working fine. So, I'm going with it overheating and the thermal protection kicking in. So, the Crowns and Peaveys are each in their own cases.

Interestingly, I had to reset the limiters with this A & H board down a notch from the Behringer board I was using. Glad I checked it.

So, it's off to the shows this weekend. Kind of looking forward to Fridays show because I get to sit there an play soundman. Emphasis on "playing".

Thank you all for your help.

Dan56
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Re: HELP! How would you use 2 crown xls and 2 peavey IPR's

#14 Post by Dan56 »

Just wanted to report back that the amps did fine for the past 2 days. Yesterday they were driving monitors and some traditional subs with 2 15's in each. 4 total. Today they ran my speakers, the OT12 and T39s.

I had purchased a Peavey IPR2 5000 and ran all 4 off of it, using the 1600 and 3000 for the monitors. Left the Crowns on the side for security.

No issues at all.

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