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CREST Pro 9001 - 4 ohm performance

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ReubGold View Drop Down
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    Posted: 16 February 2017 at 11:11am
Friend been using one of these for years, to power 4x Scoops.

Depending on building power, sometimes great, sometimes OK.

Recently borrowed Crown 5000VZ, and couple of other lightweights to compare.

They all achieved better SPL on average, than the 9001. Confused

Recently read amp has 10KVA transformer, so that means you only really get full performance at 2 ohms stereo?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Aurora Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 11:15am
The 9001 likes a stiff 32amp supply for full performance, you can get away with using it on 4ohm on a 13amp plug but won't full reach full potential, the Crown is a bit more forgiving if you have to use 13amp sockets.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote levyte357- Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 11:21am
I've seen Crest 9001 on stiff 32A supply, powering 4x cabs many times,  and amp was always clipping before drivers were fully powered.

Spec says 2kwpc @ 4 ohm, which lines up, with what I've seen.

Inf8MK2 on 32A, at 4 ohm stereo, could easily have sent the voice coils into the upper stratosphere.
In fact, it is like that on decent 13A supply.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dub Specialist Sound Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 11:51am
Disagree man

9001 been benched way exceed the stated specs, i know diff when acually driverinf drivers,

but Crest has allways been conserative with spec power, heard it excells on 64a , 

dont know never tryed it
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dub Specialist Sound Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 11:53am
Load them Crest up man, thats what tha built for, 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote levyte357- Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 12:08pm
Originally posted by Dub Specialist Sound Dub Specialist Sound wrote:

Disagree man

9001 been benched way exceed the stated specs, i know diff when acually driverinf drivers,

but Crest has allways been conserative with spec power, heard it excells on 64a , 

dont know never tryed it


Would agree, at 2 ohm it must be mad on big power.

But time after time, seen sounds playing 9001, 1850s, 4 ohm stereo, on 32A at GP, and amp was clipping, long before 1850s were in trouble.

Inf8mk2, even on 13A supply, can have 2x 1850s per channel in trouble.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote logsquared1 Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 2:44pm
Originally posted by ReubGold ReubGold wrote:


Recently borrowed Crown 5000VZ, and couple of other lightweights to compare.

They all achieved better SPL on average, than the 9001. Confused

Something is wrong with the 9001.  Possible the high side of the class H circuitry is not working.  The amp will still work it will just clip at half the rail voltage.

The 5000vz and the 9001 have very similar max rail voltages.  IIRC, the 5000 is about 144V peak and the 9001 = 150Vp.  Therefore they should put out very close SPL with the crown a little lower (probably unnoticeable).

I have owned over 8 MA5000's and 10 9001's.   I still use the 900'1's weekly in three different club installs. 

The crown does have a more aggressive sound (distortion).

My personal experience is the crowns are pieces of shit.   Almost all of the ones in my inventory failed multiple times.  Luckly, crown was only 20 min from my shop.  After the 3 year warranty was up they all got sold.

The OPEP circuitry was crown marketing hoopla meaning we are going to put in less transistors than needed and put a protection circuit in to keep them from blowing up.   

The MA2400 and lower were great amps.  The MA3600 = utter garbage.  Once a crown engineer told me they tried to get the company to not release the 3600.  They did anyway.

The 9001 is a real workhorse.  I have run at 2 ohms in a pinch many times no problem.  In 15 years I have only had two failures out of 10 amps.  What you get in performance you pay for in weight. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote B_Bender Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 2:48pm
how does the plug its got on the end make a difference to the amps performance? surely just the supply voltage on these older amps?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sinai Sound Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 3:01pm
Consider that the average impedance of 2 scoops per side isn't really 4ohm

Those with a Powersoft K series DSP will know what I mean

With 4 x PD1852 in polar scoops, that's about 3.5 ohm average 

I'd personally try all 4 on one side of the 9001 to see what it sounds like


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Post Options Post Options   Thanks (1) Thanks(1)   Quote MarjanM Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 3:10pm
Lev, pushing 100-200W per box more will gain you like 0.3db at a risk of burning coils.
Need more sub? Bring more boxes.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote levyte357- Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 3:13pm
Yes, "on average", 8 ohm can be realistically 10-12 ohms.

However, I've personally witnessed a number of times, Void Infinite 8Mk2, with 2x 1850 cabs per channel, outplay 9001 doing the same thing.

Would agree, on real stiff 32A supply, 9001 with 4x cabs per channel, would probably outplay same on Inf8MK2, but 2x cabs per channel, the Void is definitely exceeding it's 2400wpc spec.

Think the problem is, 9001 PSU efficiency, and really, really stiff mains supply needed, even if only driving 2x cabs per channel.


Edited by levyte357- - 16 February 2017 at 3:17pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote levyte357- Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2017 at 3:15pm
Originally posted by MarjanM MarjanM wrote:

Lev, pushing 100-200W per box more will gain you like 0.3db at a risk of burning coils.
Need more sub? Bring more boxes.



We're comparing  2x cab per channel performance of 9001, and other amps.

Please leave out the irrelevances.
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