amp for driving 8 subs ? - AVS Forum
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post #1 of 15 Old 06-30-2013, 02:24 AM - Thread Starter
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currently ive been using some ab international 600a's to drive my micro wreckers

well techincally 2 600a's and one musysic 4500
one amp per pair of subs @ 4ohm load

now i have 4 pairs of micro wreckers so it would be nice to have one single amp to drive them all , if possible

each sub has a dual 2 ohm vc driver

i would like to drive 4 per channel on a 2 channel amp , or 2 per channel on a 4 channel amp

what are my options out there for a good quality amp that isnt ubber expensive

i need 450-575w rms per sub

so if 2 channel amp i want around 2,200 w rms per side
and if a 4 channel i need around 1,100w rms per side
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post #2 of 15 Old 06-30-2013, 12:21 PM
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The Cerwin Vega CV5000 or Peavey IPR 7500 is probably going to be your best bet.

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post #3 of 15 Old 06-30-2013, 12:53 PM
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or, if you can wire them for 4 ohms per side, inuke 6000dsp.

http://forum.speakerplans.com/behringer-inuke-nu6000-vs-kam-kxd7200-bench-tested_topic69202.html

series each for 4 ohms per driver.

series parallel 4 drivers for 4 ohms per side.

Listen. It's All Good.
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post #4 of 15 Old 06-30-2013, 02:00 PM - Thread Starter
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i do have a single ab international 1100a amp here that will do 1100wrms per channel @ 2 ohms which could take car of 4 cabs
i picked up a bunch of theese amps on ebay for 150-200 bucks each but that package only had a single 1100a in it the rest were a 900 and the 600a's

has anyone here actually tested these amps , ive been told they are very very good amps but have seen no test data on them
im thinking if i can find another 1100a for 2-300 bucks that might be the way i should go. since the more i thought about it splitting the subs up at 4 per amp would be better incase i had an amp die during a gig
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post #5 of 15 Old 06-30-2013, 03:19 PM
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For gig redundancy, you could do 2 DCX's and 4 EP4k's
Or just 4 nu3kDSP's

That would give you ~7040watts RMS into 8 4-ohm loads.
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post #6 of 15 Old 06-30-2013, 09:21 PM - Thread Starter
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Quote:
Originally Posted by LTD02 View Post

or, if you can wire them for 4 ohms per side, inuke 6000dsp.

http://forum.speakerplans.com/behringer-inuke-nu6000-vs-kam-kxd7200-bench-tested_topic69202.html

series each for 4 ohms per driver.

series parallel 4 drivers for 4 ohms per side.

i dont like the fact that the inuke 6000 will shut its self down when in 4ohm stereo, im playing alot of music with very very low bass, last thing i need is the chance my amps could shut down on me


i think i found another 1100a for 375bucks with shipping , if the amp checks out i think thats the route im going to go

my 600a's have been used in 4 ohm loads in stereo at max output for 4-5 hours on end without issues so far so i know i can trust the ab amps , i just wish they had active cooling , they have one internal 80mm fan and the heatsink on the rear is passive cooling, i just setup a fan behind my rack to keep them cool while giging


though im also considering some of the lg clone amps from sanway , but i still have alot of reading in that thread to go still
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post #7 of 15 Old 07-01-2013, 04:04 AM
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What makes you think that the iNuke-6000dsp will shut itself down when presented with s 4 ohm load, in stereo? I know that the iNuke can not handle a 2-ohm load, but it should be just fine with a stereo 4 ohm load. Correct me if i am wrong.
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post #8 of 15 Old 07-01-2013, 07:42 AM
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While each sub has a dual 2-ohm coil, the DC resistance alone is the lowest possible impedance.

My cabinet is wired as an 8 ohm load (dual 4s in series). My minimum impedance in band measured 9.52 ohms at 22 Hz, which is 2 ohms higher than the DCR. The average from 20 Hz to 1200 Hz is over 21 ohms.

So - though yours are dual 2, I'd expect the minimum to be the DCR plus about 1 ohm, or about 4.5 ohms per cabinet, and the average to be closer to 10 ohms.

Things should be fine. I've never shut my bridged Inuke 3000 down, but I'm not gigging with mine.
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post #9 of 15 Old 07-01-2013, 07:57 AM
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Quote:
Originally Posted by LTD02 View Post

or, if you can wire them for 4 ohms per side, inuke 6000dsp.

http://forum.speakerplans.com/behringer-inuke-nu6000-vs-kam-kxd7200-bench-tested_topic69202.html.2.gif

series each for 4 ohms per driver.

series parallel 4 drivers for 4 ohms per side.
I like the fact that the inuke 6000,but i don't consider some of the lg clone amps from sanway , and i still have alot of reading in that thread to go still.
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post #10 of 15 Old 07-01-2013, 09:26 AM
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Quote:
Originally Posted by davece View Post

i dont like the fact that the inuke 6000 will shut its self down when in 4ohm stereo, im playing alot of music with very very low bass, last thing i need is the chance my amps could shut down on me

Thats not ture. it's possible that who's ever unit did shut down had other things going on but I've beat mine up i my own HT with my 21's and lent it out for a few gigs to a friend on his 21" strokers. 4 straight hours at 135db and it never even winced, let alone me beating it up with 10hz tones. Never shut down, nothing. And my friend has used it a few times for different gigs. Says it was great.

Blasting brown notes for 10 years and counting!

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post #11 of 15 Old 07-01-2013, 09:30 AM - Thread Starter
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Quote:
Originally Posted by N8DOGG View Post

Thats not ture. it's possible that who's ever unit did shut down had other things going on but I've beat mine up i my own HT with my 21's and lent it out for a few gigs to a friend on his 21" strokers. 4 straight hours at 135db and it never even winced, let alone me beating it up with 10hz tones. Never shut down, nothing. And my friend has used it a few times for different gigs. Says it was great.

in that test thread the guy doing the testing said the amp shut down on him when he was testing it in 4 ohm stereo at max output . maybe i missed something cause i didnt finish reading the entire thread
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post #12 of 15 Old 07-01-2013, 10:02 AM
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Quote:
Originally Posted by davece View Post

in that test thread the guy doing the testing said the amp shut down on him when he was testing it in 4 ohm stereo at max output . maybe i missed something cause i didnt finish reading the entire thread

That portion of the testing was done with a continuous sine wave. The amp was reportedly drawing 24A from the wall (remember, the UK uses 240 V, not 120 V) before it shut down.

It was producing close to 2.2 KW/channel, and drawing 5800 watts from the wall to do it. Not a surprise that it shut down, as that sort of continuous power is well past what the fusing can handle.

When tested with a 33% duty cycle at 31 Hz, the iNuke delivered 1.8 KW per channel, both channels operating, though it was drawing peak currents of 80A (at 240V) to do so.

That would be 450 watts per cabinet in your situation, provided you have the power at the wall to get there.
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post #13 of 15 Old 07-01-2013, 11:10 AM - Thread Starter
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Quote:
Originally Posted by lilmike View Post

That portion of the testing was done with a continuous sine wave. The amp was reportedly drawing 24A from the wall (remember, the UK uses 240 V, not 120 V) before it shut down.

It was producing close to 2.2 KW/channel, and drawing 5800 watts from the wall to do it. Not a surprise that it shut down, as that sort of continuous power is well past what the fusing can handle.

When tested with a 33% duty cycle at 31 Hz, the iNuke delivered 1.8 KW per channel, both channels operating, though it was drawing peak currents of 80A (at 240V) to do so.

That would be 450 watts per cabinet in your situation, provided you have the power at the wall to get there.

ahh ok i didnt get to read the whole thing , im currently at work and reading sections when i have time.
we have some 240v 100 amp circuts in the building, other then that everything is 120v 30 amp, the building is an old industrial building, used to be a furniture factory

heres the specs on the second 1100a im looking at
Two channel amplifier
525wpc @ 8 ohms
850wpc @ 4 ohms
1100wpc @ 2 ohms
1300w bridged mono at 8 ohms
1700w bridged mono at 4 ohms

total cost to get it here would be 334$'s

spec sheet
http://www.abamps.com/pdfs/900a-1100a.pdf
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post #14 of 15 Old 07-01-2013, 04:08 PM
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"in that test thread the guy doing the testing said the amp shut down on him when he was testing it in 4 ohm stereo at max output . maybe i missed something cause i didnt finish reading the entire thread"

yeah. a little knowledge can be dangerous.

that was a sine wave into 4 ohms both channels
driven to shutdown.

in the real world, speakers have impedance,
which means the resistance varies based on the
frequency.

the only point where impedance gets close to
resistance for most subwoofers is either very,
very, low--something like 10hz--or at the tuning
frequency in a ported cab.

so it is only those instances where the sub
will be pulling maximum current through the power
supply, which is what caused the shutdown in
the first place.

Listen. It's All Good.
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post #15 of 15 Old 07-03-2013, 09:36 PM - Thread Starter
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ended up buying that 1100a the inuke would have been nice , but sinc ei already have some ab stuff i know it will handle what im throwing at it pretty easy , that and the price was right , those amps cost a few thousands bucks each new so
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