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Topic: SW Power limitator

Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000

posted 09-22-2001 02:16 PM

Hello everyone.

Few time ago I heard on this forum about a power limitator for a subwoofer, instead of lower its volume.
I'm trying to build my own subwoofer with one JBL 46cm (2440) and I wish to put it (temporarly) in my theater (600 seats, someone will remember the photo of the other 2440 opened from side to side).
To avoid sure overloading, I wish to install a power limitator that limits the input power to xxx W and maintain it while the current is > of xxx.
Question: is there a device like this? Can I build it by myself? Is is exensive?

Thanks for your help!

Antonio

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 09-22-2001 04:53 PM

Install a compressor/limiter on the input to the amplifier and set ts threshold to the max power you want out of the amp

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 09-23-2001 12:25 PM

I hope you aren't going to use a JBL 2440 as a subwoofer...since that is/was a compression HF driver (4" diaphragm with 2" exit) you are bound to be disappointed with it's bass response below 500Hz.

Now the 2240 is a LF driver...probably not best suited for subwoofer duty but it can certainly be used as one. I don't recommend compressors for those that don't know what they are doing since they can have a negative result if the power is effectively held at a high level due to sever compression.

Steve

------------------
"Old projectionists never die, they just changeover!"

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000

posted 09-23-2001 02:59 PM

Steve,

It is one of the speaker in the 4668 (or 4688, I'm sorry I don't have the specs right now) subwoofer we spoke few times ago. I will build my own subwoofer and I will put it in my new Home Theater room...
I think that it will sounds better than my 80W CANTON active subwoofer...
It will be powered by a Crown MT 2401 (perhaps I will exchange the amplifier with a 1201 or 601, what do you think?)
I think that that speaker will be enough for a 30mq room. I didn't check with dolby formulas yet!

Two questions.
1. Where can I found a compressor/limiter
2. Steve: I'm sorry but I didn't understand very well what do you mean with "I don't recommend compressors for those that don't know what they are doing since they can have a negative result if the power is effectively held at a high level due to sever compression".

Thanks for your help!

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 09-23-2001 03:09 PM

DBX , Yamahaa, Ashley all make compressor/limiters

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