Quick & Dirty 4430-Inspired Two-Ways Part I

[TimG]

Yes, I used the P-Audio 1" to 1.5" throat adapter that Zilch sent me to measure the horns with the JBL 2427H. I attempted to use a Selenium 1 3/8" threaded to 3 bolt adapter to attach the driver to the P-Audio adapter, but the Selenium bolt pattern was too wide to line up with the throat adapter. This adapter here http://store.steelsound.com/Detail.bok?no=428 looks like it may work with the 2427H.

I recieved a pair of the horns used in new SRX 715 last week, and I have a pair of 1" to 1.5" JBL adapters 339308-001 $19, as used in this speaker and others http://www.jblproservice.com/pdf/AE%...2212,64-WH.pdf, on the way. I'll post results of these horns with a B&C DE25 as soon as the adapters arrive. Now that I have the 1.5" throat horns I will try to obtain a BMS 4555 driver to measure as well.

Zilch, could you post the part numbers and prices for all of the JBL horns you will soon have. I think the 12" x 12" 100 degree horn would be the most promising for home use in a 4430 style system.

[Zilch]

Zilch, could you post the part numbers and prices for all of the JBL horns you will soon have. I think the 12" x 12" 100 degree horn would be the most promising for home use in a 4430 style system.

I have 3 horns coming:

1) 338786-001 - PTF1010HF, the 100 x 100 rectangular horn, 1-1/2" throat which tomp787 is evaluating. $83 list.

2) 338785-002 - PTH1010HF, the 100 x 100 12" square horn, 1-1/2" throat, the one Guido is trying to get for his 4435 project. $84 list.

3) 126-00013-00 - the round OASR horn with 1" threaded throat, used by sebackman in his HT project. $38 list.

The 339308-001 adapter Tim mentions will allow 2426/2427 with throat adapters removed to be used with the first two "Progressive Transition" waveguides. As sebackman showed in an earlier thread, 2426/2427 will screw directly onto the OASR horn. $19 list.

I'm thinking the P-Audio 1" to 1-1/2" adapter will allow using LE-85 and other 3-bolt 1" drivers with the PT horns, and I also have some other adapters here to mess with, if necessary.

I'll post pics of this stuff here when and if it comes next week....

A major outstanding question for this thread's projects is whether any of these newer horns are suitable for use down to the 4430's 1 kHz or the L200B's 800 Hz crossover points. The lowest I see them used is 1.1 kHz in JBL products.

[Zilch]

LE-85's (alt 2426J) mount to P-Audio horns with 1" to 1-1/5" P-Audio throat adapters mentioned above. Total assembly is 9" deep from rear of LE-85 to mounting surface. These would retrofit into L200 easily, which has 12-3/4" depth, but it's a squeeze to fit this 12" x 12" horn into the approximately 13" available baffle space above the woofer there.

Run on the N200B crossovers shown, they have to be padded down about 10 dB to get into the middle of the operating range of the stock level controls. I'll get more precise with this once RTA instrumentation gets here. HF boost seems to be adequate, tho we need to generate the curves to be sure. N200B inverts the phase.

At this 800 Hz cross frequency, I could hear the 2370A horns in System A, but these PH-316's sound fine that low, and provide a substantially broader vertical field, even mounted sideways. They're cleaner sounding biamped through the crossovers with M552 (24 dB/octave), so reworking them accordingly and adding bypass caps would likely be a worthwhile endeavor.

Time to bring the L200's up from the dungeon too, probably. It looks like there's at least this one good option to resurrect them. They're about 5.25 cu.ft., with two 4" x 7-1/4" deep ports. Sound familiar? That's 4430 size. Plugging one of the ports is gonna move the tuning down nicely, so off to the local plumbing store for proprietary tuning devices. We'll see if it gets better with the newer horn options....

Note: Labels on LE-85's say "8 Ohms." They're 16 Ohms nominal, of course, measuring 6.0 and 6.4 Ohms DCR. Whatever. They work, and sound good, is what.

[Excuse the kludge. I'll clean it up later. ]

[Guido]

2) 338785-002 - PTH1010HF, the 100 x 100 12" square horn, 1-1/2" throat, the one Guido is trying to get for his 4435 project. $84 list.

I'll post pics of this stuff here when and if it comes next week....

And they really told you they are available??

[Zilch]

And they really told you they are available??

Hi, Guido!

Allegedly, they accepted my order and shipped complete, though they DID have a problem figuring out what I was ordering, and it took a couple of phone calls to make it happen. We'll see this week.

From what I understand, these items are not available for sale as components, and there is only limited (if any) stock for replacement parts. Otherwise, they have to pull from their production stock and order anew to replace it. That's why they're hard to get -- we give their inventory control fits purchasing this stuff in any quantity.

If they actually come, I'll be posting pics here. Then I'll gloat for a day or two before ordering up some for you if you want them and can't obtain them direct. I doubt they're on the Department of Commerce "Prohibited Technology" list.

I'd be real interested to see the results of your evaluating them with 2431H. I'm planning on doing that, too, as well as running 1" drivers (LE-85, 2426/7) on them and the smaller rectangular version, which may fit L200 cabinets better than the 12" square format. From my experience with 2370A horns, though, I doubt the smaller PT waveguide will reach down to the requisite 800 Hz for an L200B swap comfortably.

We're gonna need to develop the optimum HF boost crossover topology as well, as you know....

[Zilch]

Looks wrong, sounds good. P-Audio PH-316 on LE-85's using N200B crossovers, padded down. Choose horizontal beamwidth by rotating the horns. Here, W-I-D-E. Thanks Ian, Tim, and Widget. I think we've got the P-Audio horns figured out.

4430's? Nope. Not yet....