JBL Performance Series

[JBLnsince1959]

OK Dome, now is the time for comparisions

2 questions
1. How does the PS 250 sound next to a regular 250 ( you mentioned a liitle - details)
2. more importantly how does it sound against a regular PS stack.

also, are you using the original 250 tweeter and woofer in here, if you are, do you plan to put all the PS tranducers in there???

great work.. wish I had been the first to do this ( still might depending on what you write )

[maabx]

Thanks Don C for the corrected link.

The fuse was blown. And...it keeps blowing. Bummer. Does anyone have any clues as to which components I should check for failure? Is there a common failure mode on the PS1400? I'm pretty sure it was a surge, or low voltage condition that caused the problem.

Thanks for any help.

[Titanium Dome]

Here are two shots of the left PT250, with and without flash. The left XPL200A is next to it, in in these photos you can see the stack of gear that supports the XPLs.

Top to bottom:

• Zenith DVD player (LG manufactured) used as transport with digital out
• Niles IPC6 power sequencer
• JBL DX-1 external crossover with XPL200A cards
• Fogate Audionics FAP T1
• Fosgate Audionics FAA 1000.5 (four channels driving XPLs)
• Fosgate Audionics FAA 1000.5 (two channels driving FS 400 subs)
• Nintendo Wii
• Fosgate Audionics FS 400 sub (with LE14H-1 inside)

[Titanium Dome]

Here's the right PT250, just to prove I have two.

[Titanium Dome]

To answer the question "What drivers did I use?" the tweeters are 044Tis that I took out of a pair of 240Tis I have. The diaphragms were replaced and new pads installed in 2003 according to the guy I bought 240Tis from. The poor 044-1 drivers they replaced were both abused and worn out; they will not be missed.

Grumpy and I retrofitted the housing to work in the L250 cabinet. We also discovered the need to reverse its polarity to get it to play nice with the other drivers.

[Titanium Dome]

The wonderful 904Ti replaces the tired LE5-11. At 4313B's (long time ago) and GT's (recent) suggestion, I stuffed the dog house with extra batting for the 904Ti.

[Titanium Dome]

The equally wonderful 908Ti replaces the venerable 108H. I like the 108H, but the 908Ti in conjunction with the 904Ti and a Ti tweeter (044Ti in this case) just sound so much better.

The 908Ti's operational frequencies are fairly narrow in this application, but we found that it adds a lot to the overall sound and brings both bite and presence to the party. It's doghouse got some extra batting, too.

That big inverted dome does funny things with the camera's light optics.

[Titanium Dome]

Everyone's seen the LE14H-1, but here it is again. These came from the donor 240Tis as well, having been refoamed in 2003. They'd sure look nice with that PS1400 trim ring on them. If anyone has a ring they'd like to sell, let me know. JBL does not have any, or so one rep said.

[Titanium Dome]

What's outside the box is as important as what's inside. The PT250 is a four-way, quad-amped, active external crossover design.

We left the original L250 crossover inside so the L250 can be returned to original condition if needed. No permanent modifications to the enclosures were made.

The original driver wires were rerouted and connected to four external Hafler amps that are controlled by two BSS 366T Omnidirve Compact plus units. These are six channel loudspeaker management systems, so only four channels are in use for this project. The BSS units and amps are connected by four pairs of balanced XLR cables, and each amp drives a specific pair of drivers: one drives both woofers, another both mid bass drivers, etc.

The system's pre is a Citation 5.0 in stereo mode with a Denon DVD2900 as the source.

That's lots of lights when everything is running.

[Titanium Dome]

Here's a flash photo with the body count.

In the rack:

• Citation 5.0
• BSS 366T controlling the right PT250 and the "A" channel on all the amps
• BSS 366T controlling the left PT250 and the "B" channel on all the amps
• Niles IPC12 power sequencer
• Denond DVD2900
• Unused (for now) karaoke mixer

The amps:

• Hafler SR2300 (300W/ch @ 8 Ohms) for 044Ti drivers
• Hafler SR2300 (300W/ch @ 8 Ohms) for 904Ti drivers
• Hafler SR2300 (300W/ch @ 8 Ohms) fro 908Ti drivers
• Hafler SR2600 (600W/ch @ 8 Ohms) for LE14H-2 drivers

[Titanium Dome]

This may show the slopes and crossovers better. You can see how narrow the band is that the 908Ti covers. Grumpy has some actual graphs.

[Titanium Dome]

This dark, awkward shot shows the extra flexibility afford when the amps have individual gain for each channel. Each driver's gain is adjustable. That's pretty freakin' cool.

[80sKid]

Wow. Such gear porn!

The SPL capability of this system must be pretty crazy.

I find it interesting that you are adjusting driver balance with the amps, instead of the BSS crossover units. I would think the latter would provide much more consistently repeatable results.

[Titanium Dome]

Perhaps grumpy will chime in with some added insight and maybe a graph or two. We both felt the effort paid off handsomely and that it's probably not done. It's just that after finally getting them up and running they sounded pretty darn good with minimal tweaking, and we just wanted to listen to music.

Fine tuning will certainly bring more to the experience, and we had a table and equipment in the way of complete enjoyment, but we played it loud and played it proud.

I also did some switching back and forth between the XPL200s and PT250s. We accomplished this by using the remote zone on the Citation 5.0 to feed the DX-1 inputs. Thus, both had the same source and pre, but not the same crossovers and amps. It took some futzing around to get a similar output level, and it was still not perfect, so that's a caveat. Nonetheless, I don't know how else to describe it other than sad. I mean, the XPLs should not be in the same room.

Now that they're up and running, I'll work on cleaning up the spider's nest of wires, experiment a bit with some treatments at first reflection points, and keep working on getting a mounting plate made up for the TM025 tweeter and EOS Waveguide.

There's also a noise issue from the BSS units, as they are fan cooled just like a server, though not quite as loud. The Haflers are fan-cooled as well, but the fans rarely came on, even at crazy levels, and they were very quiet.

At some future date, we'll get back together and work on fine-tuning this already great sounding system!

[Titanium Dome]

Your answer is below if you put the two together. I'm always in favor of enjoyment in the moment and improvement over time.

Wow. Such gear porn!

The SPL capability of this system must be pretty crazy.

I find it interesting that you are adjusting driver balance with the amps, instead of the BSS crossover units. I would think the latter would provide much more consistently repeatable results.

Perhaps grumpy will chime in with some added insight and maybe a graph or two. We both felt the effort paid off handsomely and that it's probably not done. It's just that after finally getting them up and running they sounded pretty darn good with minimal tweaking, and we just wanted to listen to music.


At some future date, we'll get back together and work on fine-tuning this already great sounding system!