Thanks for the Help

[alskinner]

This is my first post. Just wanted to say thanks to all the members for providing the information and enthusiasm for me to finally do something I have always wanted to do, that is to build a set of Hybrid JBL monitors. I would especially like to thank Ian, Mr. Widget, Griskard for the plans and information on the 4344/4345 monitors, 2397 smith horn and the other drivers. THe pictures( if I can load them right) are the end result. Again thanks to all for providing a forum where JBL nuts can gather.

Sincerly
alskinner

[4313B]

Very Cool!

Please post a few more pictures.

[Mr. Widget]

Tell us more about your system, like which amp goes with each driver etc. I recognize the Threshold and Bose amps... what are the other two, and what are you using for a preamp?

Widget

[alskinner]

Well, I little about the system right now I am using an Ashly XR4001 for the crossover. The amp on top going to the 2235 bass is a Sunn SPL 9000, realy gives a tight controlled bass. The second amp down is a Thresold Stasis Two connected to the 2012 midbass. THe trusty old Bose 1801 is connected to the 2441 horns and the Audio Matiere Accordance EL34 tube amp is connected to the 076 tweeters, really provides an accurate high end with out being harsh. The speaker cabinets are 7.0 cf tuned to 32 hz. I know that is over the JBL recommended 5 cf but it sounds great.
As for the preamp I run either an Soundblaster AWE64 Gold, M-Audio Audiophile 2496 cards or a Soundcraftsmen DX3000 preamp. I also have a pair of L300s and a pair of Altec A7s.

[scott fitlin]

Those horns!!!!!!!!!! I like them, very much!

[Zilch]

OOoooooo, 076's!

[boputnam]

Originally posted by alskinner
I am using an Ashly XR4001 for the crossover.

Congrats!! Nice work.

Tell us (er, me...) about the XR4001 - Widget and I are fans of their two-way, but haven't tried this. I've been hoping Ken Patchalphabet would get one...

[alskinner]

The Ashly XR4001 has performed superbly. Being able to dial in the exact crossover frequencies and adjust the filter curve greatly reduced the manhours finding the right values for a passive. The sound is dynamic and smooth unlike some of the other op-amp electronic crossovers on the market. I have most of the components to build a set of passives, but like the sound of the Ashly so much I have put off building them until later. The crossover is an excellent tool for building 4-way speaker as you can cut out individual drivers in order to track down problems. Of course the down side is having to get 4 ampsl to live in harmony without ground loops.

[Robh3606]

Very Nice speakers! Where did you get the Smith horns??

Rob

[speakerdave]

Nice work. I'll bet they sound really good.

I second the question about the Smith horns. Did you make them yourself?

I'd be interested in a detailed comparison of that cat's eye tweeter and the 077 in your L300's.

Originally posted by alskinner
The speaker cabinets are 7.0 cf tuned to 32 hz. I know that is over the JBL recommended 5 cf but it sounds great.

I'll bet that's one way of getting a cabinet without a big hunk in the bass response.

Thanks,

David

[alskinner]

The horns were built by Dean Labbe in Calgary Alberta Canada.
They are pure cherry and are duplicates of the Westlake Tatrix Flare horns. He also builds horns for a lot of the old Altec drivers.

As far as the box, increasing the cubic feet of the box caused a slight rise (about 1 decibel according to WINISD) in the 35 hz region. I am planning on retuning the box to 30hz which which will remove most of the hump. It also has the .5 cu ft subchamber for the 10" midbass. The box is heavily reinforced every 12 inches with 2X3 and 1X3 internal bracing and I used Dow Corning pink insulation on all sides except the front baffle. I did put a removable back panel on the back for access to the 076 driver and wire connections.

Although the differences between the 076 and 077 drivers are subtle the 076 IMO has a smoother dispersion and gels with the 2441s better. One of the things I test tweeters on is their ability to reproduce cymbals accurately. The 076 IMO does this better than the 077. Of course the drawback is finding the 076s (2403s)at a reasonable price.

[4313B]

I agree with you with respect to the 076 versus the 077. However, the 077 in your L300 is at a disadvantage if you A/B it against your Ashly driven 076. It's been said that for best performance the ring radiators should be crossed actively. They only require a few watts of high quality amplification to really shine.

[alskinner]

Thanks for the response. You are right about A/B comparison against the L300s. I have a spare set of 077s that I tried first in the new speakers and there is diffenately a difference between being actively and passively crossed.

[johnaec]

So how do you like the 2012H's? What crossover frequencies are you using?

John

[alskinner]

I really don't have anything to compare the 2012s to, but really like the response they IMO extremely accurate in the midbass frequencies. I orginally wanted to try the 2122 or 2123, but decided on the 2012 after doing research on the JBL site. I am very happy with the 2012. Right now I have the drivers crossed at 300Hz, 1K,and 10K.