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View Full Version : BMS 4590 and JBL 2397 - a good combination?



nycone
07-29-2011, 08:54 PM
I picked up a pair of JBL 2397 with 2328s and was thinking of marrying them to a pair of BMS 4590s. Does anyone have experience with a setup of this nature?

I'm new to horns and I'm not aware of the pitfalls and tips one might need. Advice is welcome.

allen mueller
07-31-2011, 03:44 PM
I ran essentially this same combination with the exception that the horn was a Westlake clone style 2397. I thought it was a good match and enjoyed the combination alot. The set up was using the standard BMS passive for the x over on the coax and an active crossover for horn set somewhere between 1k and 1.2k.

nycone
07-31-2011, 06:55 PM
Thanks for the reply.

As I said, I'm new to horns, any advice for the bottom end?

Lee in Montreal
07-31-2011, 08:10 PM
Thanks for the reply.

As I said, I'm new to horns, any advice for the bottom end?

Any woofer that goes up to 800Hz. For home duty (excluding loud home cinema), perhaps a 15" 2235h for its sweet lower extension down to 20Hz. Or even better, a 2235h for 20-50Hz and a 2225h for 35-800Hz. It all epends on how involve you want the project to be.

pos
07-31-2011, 11:41 PM
The 2397 will have directivity issues (lobes) in the UHF, and you will likely need a tweeter. So using a compression driver with an integrated tweeter like this BMS is a bit of a waste IMHO.

Concerning the woofer, you should also take in account the very large directivity of that horn, and you will need a small woofer to avoid having a gross directivity mismatch at the crossover frequency.
A 12" crossed over at 1khz will likely be a good directivity match.

nycone
08-01-2011, 12:53 AM
The 2397 will have directivity issues (lobes) in the UHF, and you will likely need a tweeter. So using a compression driver with an integrated tweeter like this BMS is a bit of a waste IMHO.

Concerning the woofer, you should also take in account the very large directivity of that horn, and you will need a small woofer to avoid having a gross directivity mismatch at the crossover frequency.
A 12" crossed over at 1khz will likely be a good directivity match.

I'd thought the 2397 was a decent match for the coax. I considered a 2380a instead or an Itawa. Did I assume incorrectly? What do you think an ideal horn would be for the BMS 4590?

Regarding the low end, are there designs folks like? The driver is only part of the solution, how are folks running them? In horns? Ported boxes? Sealed boxes?

Lee in Montreal
08-01-2011, 06:29 AM
I'd thought the 2397 was a decent match for the coax. I considered a 2380a instead or an Itawa. Did I assume incorrectly? What do you think an ideal horn would be for the BMS 4590?

Regarding the low end, are there designs folks like? The driver is only part of the solution, how are folks running them? In horns? Ported boxes? Sealed boxes?

I am petty sure that if you googled "BMS 4590" you'd find thousands of exemples of how the BMS driver was used succesfully. ;)

The answer to your second question is easy: In horns. Ported boxes. Sealed boxes. Dipole. However you like it, or for whatever purpose. It all depends on your tastes and "fantasies".

BTW I suspect that the bigger Iwata will be a better horn for a two way system. Lower cut-off and higher reach. But it is much bigger than a 2397.

nycone
08-01-2011, 09:14 AM
I am petty sure that if you googled "BMS 4590" you'd find thousands of exemples of how the BMS driver was used succesfully. ;)

The answer to your second question is easy: In horns. Ported boxes. Sealed boxes. Dipole. However you like it, or for whatever purpose. It all depends on your tastes and "fantasies".

BTW I suspect that the bigger Iwata will be a better horn for a two way system. Lower cut-off and higher reach. But it is much bigger than a 2397.

Actually, most of the posts I found were not too happy with their set up - their top end was a problem, thus this post. I thought I'd go to the "source". I found one fellow who seemed happy with the 2380a. I contacted him, and he too, had moved on.

Lee in Montreal
08-01-2011, 09:32 AM
There are very few horns that will be good from 500Hz to 20kHz. If any.

nycone
08-01-2011, 06:11 PM
There are very few horns that will be good from 500Hz to 20kHz. If any.

Lee, I'm a little lost. In your last post you refer to Googleing lots of folks who've used the driver and are happy, and next you say very few can do 500-20K well.

Remember, I've never heard a horn and driver (to my knowledge), can you elaborate on the best way to use the 4590? Any suggestions as the common or right way to do a project like mine?

Eaulive
08-01-2011, 06:20 PM
Lee, I'm a little lost. In your last post you refer to Googleing lots of folks who've used the driver and are happy, and next you say very few can do 500-20K well.

Remember, I've never heard a horn and driver (to my knowledge), can you elaborate on the best way to use the 4590? Any suggestions as the common or right way to do a project like mine?

Well, "lots of folks being happy with their driver" does not implies that it goes up to 20kHz

Lee in Montreal
08-01-2011, 06:45 PM
To make the quest more efficicient, I suggest asking BMS themselve what horn they suggest to reach 20KHz, because the driver is as good as the horn it is mounted to. Also, I have read about a lot of happy BMS 4590 owners, even though they didn't have a flat-to-20KHZ horn :D. Let's mention that the geometry of a horn that fits the midrange will not necessarely fit the higher frequencies. Which is why i'd be personally happy with a horn/driver combo that is dead flat until 10Khz, crossed over to a super tweeter such a JBL 2405.

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Lee in Montreal
08-02-2011, 10:54 AM
Specifications
Throat diameter 2" (50.8 mm)
Nominal impedance 2 x 8 Ohm
Power capacity
Middle range (AES) 150 W RMS above 400Hz
peak 1000 W peak above 500Hz
High range (AES) 80 W
peak 450 W
Sensitivity 1W/1m 118dB on 2242 Horn
Frequency range (Hz) 200 – 22000
Recommended crossover 300Hz
Middle frequenzy range 300 - 7000Hz
High frequenzy range 300 - 22000Hz
Middle/High crossover 6300Hz

It looks like BMS tested their driver with their own 2242 horn. Chances are that to get ultimate results, that's the horn to pick. But strangely, it seems this horn doesn't even exist. Not on their own site, nor in anyone's system... ;) And basically, everyone who's interested in the 4590 driver is asking the same question around the world. "Where the f... is the 2242 horn?" :D

So back to what people have used... The flat graph shown above was done with coupling the BMS driver to the German Jabo-KH-50. Has the response been electronically flattened? I don't know. Sprechen sie deutsch?

http://www.rahaso.de/foren/msg.php?f=audiotreff_hoerner&idx=14600&

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