Film-Tech Forum ARCHIVE: JBL MPX or Crown MT?

This is topic JBL MPX or Crown MT? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Antonio Marcheselli (Member # 373) on 10-29-2002, 02:41 PM:

I have the chance to buy an used JBL MPX or a Crown MT amplifier. I need to amplify a subwoofer.
What is considered the best one? JBL (QSC) or Crown?
What about for full-range use?

Any suggestion will be appreciated!

Bye
Antonio

Posted by Paul G. Thompson (Member # 655) on 10-29-2002, 03:43 PM:

Although Crown was a good unit in their day, I would stick with JBL. Better yet, if you could get a QSC, you would be better off.

Both are just my opinions.

Posted by Antonio Marcheselli (Member # 373) on 10-29-2002, 04:11 PM:

Paul,

JBL MPX are manufactured by QSC, this is why I wrote "JBL (QSC)".
I do not remember right know what kind of QSC are the JBL.

What changes between QSC and Crown in your opinion?

Ah, I noted that JBL MPX has just one transformer inside while the Crown has two of them. I see the Crown as two completely different amplifier, the QSC (JBL) one seems a bit "cheaper" to me.

Sound quality? Opinion?

Bye
Antonio

Posted by Richard Fowler (Member # 893) on 10-29-2002, 04:28 PM:

The JBL ( QSC ) amplifier is no longer manufactured and is an orphan since Harman Industries, owner of JBL, bought Crown.

Posted by Bob Maar (Member # 763) on 10-29-2002, 07:14 PM:

Antonio,

Anyone of these amplifiers, provided they have the proper power, will be fine for your subwoofer. Get your best price and go for it. They are reputable companies and stand behind their product. Let us know what you deceide.

What amplifiers are you using for the stage speakers? I would probably match what you have.

Posted by Antonio Marcheselli (Member # 373) on 10-30-2002, 05:47 AM:

Bob,

I'll use MPX for stage and surround channels. But regardless the price, what is considered the Best sounding amp between Crown MT and JBL MPX?

Bye
Antonio

Posted by Ray Derrick (Member # 1001) on 10-30-2002, 06:56 AM:

Antonio, personal opinion or preference is the LEAST reliable way of selecting an amplifier. Check the specifications. If one uses MOSFET output devices and the other bi-polar transistors you can be assured that the one with MOSFET's will sound better (all other things being equal). If one has a high capacity power supply and the other doesn't you can guarantee the former will sound better at high volumes (all other things being equal). If the specifications look very similar then listen for yourself. What sounds best is a very personal thing.

Next time I am in Italy (which is not very often) I must call in to your cinema in beautiful Florence. You sound like a man who is dedicated to his craft and I am sure you have a great sounding cinema complex. It is really nice to see someone take such an interest in wanting to obtain the very best cinema sound.

------------------
Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

Posted by Antonio Marcheselli (Member # 373) on 10-30-2002, 08:40 AM:

Hi Ray!

You embarass me with you comment!
Yes, Sound is very important to me, I've always put very attention to theater's sound. Unfortunately I'm actually working in a 16 screen Multiplex or better, a "Scratchplex"... I started the new job on september and I really realized what you mean with "film done right". My manager put NO importance on projection quality but the theater itself is not so bad, I'm proud to work there. So I started working for myself. I build up prints with maximum attention, while I see other projectionists using the floor as working table.
Few days ago I was showing to a novice how to build the ads. At some point I had in my hands a little reel of ads a bit "jammed", I was trying to free the print without damaging it and the novice pull the print from my hand throwing it on the floor to better rewind it on the working bench. I freeze him asking him to never do again something like this with me. "Others do it continuously" he replies. "I'm not the others" I stated.
So, thanks to believe that my theater has a good sound and quality but unfortunately... it is not depending from me. I really hope that the situation will change.

I worked in an old one-screen theater before. Projection quality, sound quality and all technical stuff were in my hands: I was very proud of the results!

When you'll come to Florence you'll be welcome!

Coming back to the amps...

I believe that both JBL and Crown are not MosFet driven. My olny concern is about the split power supply of the Crown. MPX series has just one power supply for both channel.

Bye
Antonio

Posted by Ray Derrick (Member # 1001) on 10-30-2002, 08:57 AM:

Antonio, the split power supply will result in superior left/right independance, or better separation between the left and right channels (at high power levels). If you are running the amp in bridge mode then it will make no difference whatsoever.

Last time I was in Italy (a few years back) I drove down from Vienna in Austria through that 17km long tunnel to Venice (not that far from Florence). On the way back I visited Verona, then on to Bolzano, Merano and then on to the Engadin Valley in Switzerland. What a truely lovely part of the world!

------------------
Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935