New JBL Series Sound Reinforcement Boxs

[Oldmics]

They are using the differential drive coil scheme (as in the Eons).

It will be interesting to see how this fares out.



Follow the link below




http://www.jblpro.com/srx700/index.htm

[johnaec]

They seem to be using differential drive design in more and more of their stuff, including some of the AM dance club stuff, and obviously the Vertec series. They're also using DD on their high-end car subs.

I'd really like to see a comparison in distortion/frequency response/output with their traditional drivers sometime. I'm thinking there must be some reason, (price? other?), that they haven't filtered into studio/home systems.

John

[Zilch]

Somebody explain differential drive....

[boputnam]

Originally posted by Zilch
Somebody explain differential drive....

JBL combined neodymium with the Differential Drive speaker. The Differential Drive system uses two voice-coil windings on a single voice-coil former. This greatly simplifies the magnetic circuit and eliminates the need for a heavy steel back plate - further reducing speaker weight. But the benefits of neodymium Differential Drive® technology extend beyond weight reduction. Since this design results in a symmetrical magnetic circuit, significant reductions in even-order harmonic-distortion are achieved.

From the Eon product lit.

[boputnam]

Hey, Oldmics...

Have you heard these? The line has a lot of similarities to EV's QRx line, which I like quite a lot. The SRX715F is a dead-ringer for the QRx115/75. Hmm...

[Zilch]

Originally posted by boputnam
The Differential Drive system uses two voice-coil windings on a single voice-coil former.

Yeah, well, dual voice coils have been common for a while, now, in subwoofers, for example. You drive one from each channel, and the speaker sums left and right electomechanically.

This is allegedly different, though, the coils not being wound on top of each other, rather, displaced? And operated in parallel but reverse polarity? I'm not gettin' this; I need pictures. Send me somewhere to a tech brief or something. I need to appreciate it ain't just hype....

[johnaec]

Originally posted by Zilch
Somebody explain differential drive....

Check out all four sections under GTi SUBWOOFERS: The Technologies http://www.jbl.com/car/products/gti/gti_tech.asp

They are about their car subs but explains the technology pretty well. There's also probably a lot of info in the Vertec docs.

John

[Zilch]

Thus renewing my commitment to making an isobaric LE14A triple-chamber bandpass sub.

Just one more LE14A to find here....

[Don McRitchie]

I'm thinking there must be some reason, (price? other?), that they haven't filtered into studio/home systems.

They've been a core technology of the LSR studio monitor line for the past 5 years. They are also used in the K2 center channel and 4348 home speakers. They are very low distortion devices with lower levels of power compression than any other JBL driver type.

[johnaec]

Originally posted by Don McRitchie
They've been a core technology of the LSR studio monitor line for the past 5 years. They are also used in the K2 center channel and 4348 home speakers. They are very low distortion devices with lower levels of power compression than any other JBL driver type.

"Didn't realize they were in that stuff - I'll have to do a little catching up...

John

[Don McRitchie]

Here's a cross-section image of the 12" DD woofer from the LSR32 and description.

[mikebake]

I'd like to hear the SRX738.............................nice full range cab.

[Oldmics]

You can see the stacked coil design.

To Bo

I have not heard the EV stuff.I really liked the RMD design of the X-Array.(Can I say that on this Forum??????) I will investigate futher.Thanx for the tip.

Oldmics

[Alex Lancaster]

And the dealie with a wire (right in the middle) is a resistor for the brake?

Thanks, Alex.

[Zilch]

Didn't read about any brake, though it is shown as a separate coil there....