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Crown and JBL SRX


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#1 Hawk

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Posted 14 January 2006 - 11:00 AM

Mornin',

I am using a pair of JBL SRX 715's, in a club rock band, moderate volume.
I have switched to these, from EV Sx 500's, wich I was always satisfied with, till I heard the SRX.
Cleaner mids, and top end. Slightly less bass (smaller, lighter box, better on the back) but that was quickly fixed with a Behringer Dualfex Pro. Vocals, and a little bass drum only, indoors.

I have been running the SRX with a K-1. Sounds great, but I would like a liitle more headroom.
(Second K-1 runs monitors)
I have always used Crown, but am now confused with all the "choices"?

I don't need a lot more power, but I do like lots of headroom.

I would like to be able to run the 2 SRX with one channel, and "occasionally" run a pair of 8 ohm 18" subs, with channel two, when we do an outdoor gig, or a large party.  
(Tho, I could run the SRX with a new Crown, and the subs with my K-1?)

The question, which Crown?

K-2?  I really like my K-1, just want a little more.
CE4000?  I used one in an outdoor situation once, and it just sat there and "clicked" at me. No sound?  
We may have had a bad/dirty AC line, but all the rest of the band gear, (including my K-1, and the bass player's CE1000 ran fine?)
I DID like the Hi and Lo pass filters tho, nice touch, could be a back up "Xover?

Xs 1200? Don't know anything about these newer models.
Is it a "step up" from the CE series?
Which Crowns are considered a "step up", from the CE series?

And, being in a group that does NOT carry an electrical engineer, we have to live with the AC that is available. So, we need something efficient, that won't overload the AC circuits of the average "underpowered" club.

Which of these is the most stable in "Tough" or bad situations?  
(when the AC line isn't quite as clean, or "stable" as it should be?)

Which will draw the least power, when running "rock" at about 6-800 wats per side, moderate compresion?

I'm leaning to the K-2, just 'cuz I've had such good luck with my K-1's, Tho it is Expensive!
(did it really go up a $900 in the past 3 years?)

Thanks,  
http://www.crownaudio.com/forums/style_ima...icons/icon9.gif
Hawk

#2 DLLutz

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Posted 14 January 2006 - 03:43 PM

I was reading your post and thought I would jump in with my 2 cents;

If you are after more head room, running the JBL's off one channel would be no good. However here is an idea...

Are you crossing over the signal to the JBL's.  It might really clean them up, make them more effiencent, and increase your "head room" if you ran a high pass filter (crossover) say at 100 hz. where that the K1 and the JBL's were only dealing with freq's of 100hz and up.  I don't know how many monitors you are running but take that K1 and run the 2 18" subs in bridged mono. (lots of kick in mono 1100 watts @ 8ohms, 1500 watts @ 4 ohms).  Then look at a cheaper crown (maybe even used off of ebay) to run your monitors.  I pursched a used Power Base 2 the other day for $185.00 that had never been on the road (very clean) and even though it was made in the late 80's (made in the US by the way) its a lot of bang for the buck.  I am running it in bridged mono at 8 ohms 910 watts RMS.  (check this sight for the specs.) And had no problems.  Acutally I am using several Power Base's with no problems.

Good luck
David L.

#3 Bud Bolf

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Posted 14 January 2006 - 04:32 PM

Hawk,
   You have some power hungry Speakers.
Check here:
From the JBL site:
----------------------------------------------------------------------------------------------
System Type: 15", two-way, bass-reflex
Frequency Range (-10 dB): 40 Hz - 20kHz
Frequency Response (3 dB): 53 Hz - 20 kHz
Coverage Pattern: 75 x 50 nominal
Power Rating (Continuous/Program/Peak): 800 W / 1600 W / 3200 W
Dimensions (H x W x D): 711 mm x 439 mm x 406 mm
(28 in. x 17.3 in x 16 in)
Net Weight: 22 kg (48 lbs.)
-----------------------------------------------------------------------------------------------

The Continous of 800W is the RMS rating.
If you ran them in the 1.5 to 2X power rating,
Read this: How Much Power

  that would be between 1200 to 1600 Wrms per Cab at 8ohms!
If you parallel 2 cabs together to get to 4ohms then you need between
2400 (1.5x) to 3200 (2x) Watts RMS being put into them because they are now
sharing the load!
This is conservative, some believe that you should match the Power Amp
to the Peak rating of the speakers and that's 3200 watts per cab!

Let's look at your options:

1) You can find an Amp that will supply
     1200 to 1600 watts per channel at 8ohms.
     This excludes the K's the CE4000 and the XS series of Amps.
     Amps that Crown has that will fit this bill is the I-Tech 4000 and 8000.
     MA5002VZ does 1300wrms per channel at 8ohms.

2)  You mentioned running them Paralleled to one channel,
     that means that you need an amp that will put out
     between 2400 to 3200 watts per Channel at 4ohms!
    Again that excludes the K's the CE4000 and the XS series.
     Your back into the I-Tech 6000
  
3) I would recommend running the 2 cabs paralleled to 4 ohms.
    But not on one Channel of an amp in per Channel mode.
    For the power needed I recommend running them on a
    Bridged Power Amp running at 4ohms!
  
    Now your in a better place to find a Great and affordable Power amp.
Let's look at what amps will put out 2400 to 3200 watts Bridged.

1) At the top of my list is the CE4000. It is great when it comes to AC load
it is BCA technology, has the (PFC) Power Factor Correction, which means it runs on AC from between 100 to 240 VAC at 50 or 60Hz, and no switching needed.
You could play in NYC today and London tomorrow!
Bridged it puts out 2800wrms, smack dab in the middle of your 2400 to 3200 wrms needed!

2) The XS900 is a Great amp and I know because I own a
CE4000 and the XS900.
The XS900 has 2 fans that run continously and can be heard in my
living room but I never hear them at the Gig!
It runs Bridged at 4ohms and puts out 2500 wrms.
I've used it for my Monitors, Top cabs and Bridged on my Subs.

3) The XS1200 is just like the XS900 but is rated at 3000 wrms Bridged at 4ohms.

4) The K2 is rated at 2500 wrms Bridged at 4ohms and since you use the K1
you know about them.
The K1 however only puts out 1500 wrms in Bridged mode at 4ohms, that's
750 watts per cab.

So that's about it. In Summary:

I like the CE4000 and I like the XS900 and XS1200 and any would be a good choice.
When Crown had their last rebate on the XS and CE's,
I got an XS900 and after the rebate, it cost me less than $700.00
Plus a "Three for free" extended Warranty, making it 6 years of Warranty Coverage.
I couldn't pass it up!
  
Be carefull if you Under-Power these cabs, either way make sure
that you set your "System Gain" correctly!
  Good Luck and I hope that this helped.
        Bud

#4 Bud Bolf

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Posted 14 January 2006 - 06:14 PM

Hi again,
Give us some more information on your 18" subs.
Make and Model, Specs?
I usually (always now) have more power going to my Subs than Top Cabs.
It takes POWER to make your Subs really wake up and come alive!

My dual 15" sub cabs are rated like your top cabs with a Peak of 3200 watts.
I used to run them very underpowered with my CE4000 at 1200 wrms
per cab per channel.
They should have at least gotten double that at 2400 wrms.
I was bad and so they were OK but nothing great.

Then I did an outdoor gig and Bridged my CE4000 to one cab and the XS900
bridged to the other. They now got 2800 and 2500 watts each, depending on the amp that they were hooked up to.
And Oh my God! These cabs just woke up and thumped their A _ _ off!
I was amazed, as were my Bandmates, and friends that know US and
OUR Sound.

I now actually do some smaller indoor gigs with just one Sub cab in the middle
of the stage (power alley) and my Top cabs out to the side.
I bring in my other Sub cab when I need it.

So you could say that I was a bit of a, do as I say not as I do!
I admit it, but I learned a good lesson!
I now truly practice what Crown and others say of the correct Power to
Speaker ratio!

So you see, I have been where you are and I now know what proper powering of
speakers can do. My subs will not be ran that way again.
If I did not have 2 amp's to Bridge for both my Subs, then I
will not take 2 subs at 1200 watts and underpower each cab.
I'd take in 1 sub at 2800 watts powered correctly!

I say this because it sounds like you are trying to do, just like I have
done in the past and you can get away with it.
But when you finally do it right, you'll kick yourself for not doing it sooner!
Plus be amazed at how your System sounds.
-----------------------------------------------------------------------------------------------
This is from the How Much Power, Crown article:

  You might want to choose an amplifier that has more power than you need in case you expand your applications. Also, it's wise to specify a little more power than you need. You can always turn down a power amp if the system is too loud, but you can't turn up a power amp past maximum if the system is too quiet!
----------------------------------------------------------------------------------------------
This is so true!

So, give us some info on what your doing with your Subs.
The bottom line though is, that the better that you properly power your Speakers
the happier you will be with your "System!"

Later,
   Bud

PS. Another great "Live Sound" decision that I made was getting a DriveRack.
It works great alone, but even better when matched with JBL Speakers and Crown Amps.
The Speaker and amp settings are there.
Alright, I gotta watch some Football !!