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Thom
12-25-2006, 03:13 PM
First off, pardon me if you thought I was hijacking your thread Guido. You could have used more tact, but I got your message.
I really am interested in what you are doing. If I'm really committing some taboo pm me or something. Do not wish any confrontation. I thought I could understand what you were doing better If I understood what the target was and Zilch, thank you for being helpful there. I find it more interesting now as I didn't realise this was an accepted problem. By two way do you mean only one crossover in the fundamental range or two drivers period. Also these various drivers with 1500 in there number, I believe (might be wrong) they are oem drivers in various consumer systems. Are there spec sheets for them or do you just have to know you like them from having listened to the system and then attempt to acquire them through parts or service. I'm sure every body is busy and you don't necessarily have time to answer questions from someone who can sometimes get on your last nerve but perhaps in time I could get up to speed. I'm afraid I'm the sort of person who has great difficulty allowing anything to remain a black box.
Thank you for whatever attention you give this

Thom

Guido
12-25-2006, 04:22 PM
The thread was originally startet by Giskard
http://www.audioheritage.org/vbulletin/showthread.php?t=13538

I think we should keep the thread "clean" as I think it will be one of the most interesting ones within the next weeks and should contain technical issues only. At present it is no sense to post there as Zilch and myself are waiting for the Hxxxx horns.
Without the horns everything is guessing and nothing fact.

A lot of our forum members (me too) love the 44xx Biradial Monitors. Forums Favorite is the 4430 but I prefer the 4435. It's a question of the space you have available.
Some members use the 2425 driver with aquaplased diaphragms but there is still room for improvement. This kept some of us busy!

Since some Forum members recently got their hands on the new SOTA Beryllium JBL drivers (2435, 435Be) we searched for a possibility to include them into a "classical" 2 way design. As GT developed a compensation network for 2 way operation of the aquaplased 2435 or 435Be this is possible now.
Thanks to Giskard we (Zilch and myself) where able to order the latest in JBL horn technology.

As soon as the horns are available I think we will develop a passive crossover.

Giskard mentioned the possible woofers for such a design:
1500AL
1500FE
1200FE
LE14H-3
I added the ME150H

Spec sheets here: http://www.audioheritage.org/vbulletin/forumdisplay.php?f=59

They all should be available by contacting JBL Consumer. My ME150H will be built from 2227 cores and C8RME150H cone kits.

Thom
12-26-2006, 02:25 AM
Is the 2227 the frame that the ME150H is built on or most resembles then, not the 145? I was looking at information on the 1500AL and they seemed to be all over the map from ferrite to neodymium to alnico. The unit pictured looked much like a 15GTI but the diagram was of a speaker very different or was this because the cement was very wet so to speak. The link is appreciated and I'm sure you don't just sit by your computer all day with nothing to do but answer questions so whenever you get to things is plenty fast enough. If there were specs to the ME150H I missed them so I will look again and if they aren't there perhaps you have them. You must or you wouldn't have decided to try it. Until the 2227 were all of the .5 inch top plate frames the same except for some having extension rings? Will kits interchange between the earlier 1/2 in plate frames and the new 2227 type? I don't mean can you fit it on there.

Thank you

Thom

spkrman57
12-26-2006, 06:41 AM
http://audioheritage.org/vbulletin/showthread.php?t=11347

Ron

Thom
12-26-2006, 02:34 PM
Some of these links can be hard to find. Maybe the search function could use help. Maybe I need practice. Whichever, these links are appreciated. It would be nice if they used all the same units of measure for each driver but I'm guessing people interested enough compile their own info so ok.
It's probably not so likely, but I hope I can be of help here some day.
Thank you
Thom

spkrman57
12-26-2006, 03:02 PM
It will all get easier with more use. My 1st attempt at forums had me so frustrated that I almost gave up. My familiararity comes from a lot of hours spent here. And yes, I still have to work at searching for the hard to find info.

Stay with it and enjoy the ride!;)

Regards, Ron




Some of these links can be hard to find. Maybe the search function could use help. Maybe I need practice. Whichever, these links are appreciated. It would be nice if they used all the same units of measure for each driver but I'm guessing people interested enough compile their own info so ok.
It's probably not so likely, but I hope I can be of help here some day.
Thank you
Thom

Guido
12-27-2006, 05:22 AM
Is the 2227 the frame that the ME150H is built on or most resembles then, not the 145?

The 2227 uses the same magnet and frame then the ME150H. This was confirmed by Jerry Moro through Giskard.



Until the 2227 were all of the .5 inch top plate frames the same except for some having extension rings? Will kits interchange between the earlier 1/2 in plate frames and the new 2227 type? I don't mean can you fit it on there.

The 2227 Frame is quite unique. I'll try to post pics of the frame when I do the reconing. No older kits will fit. It will be clear when you see the pics.

I choose the ME150H as I had the 2227 cores available. Earl K highly recommend this woofer and it is for sure a step up from the older 2235/2234 woofers.

merlin
01-13-2007, 12:26 PM
Again not wanting to dilute the main thread on a TOTL 2 way, but I really wanted to know what the pros and cons are of adding a second bass unit ala DD66000 and whether active biamping would allow some tuning of the bottom octaves to suit the room.

In other words, given no cost or space restrictions, would you team the 435be with 2 x 1500AL or similar and if so why?

Hoping to hear your views

Michael

merlin
01-13-2007, 02:15 PM
I was thinking of room size and LF extension Giskard. Given the associated problems with the arrangement I read about in Project May, would the single 15" tuned slightly higher not be likely to be easier to accomodate in a small room? Or would the added efficiency and lower distortion still make the dual woofer preferable? It's kind of expensive to try both out!! Could do with a guiding hand!

merlin
01-13-2007, 06:40 PM
The really cool thing about Everest II is that both those 1501AL's are rolling off at 12 dB/octave rather than the usual 18 dB/octave or 24 dB/octave and that means they sound nice and strong in a typical listening room.

I'm confused here (it doesn't take much!). The Stereo Sound article seemed to suggest a first order low pass on the first 1501 at 150hz, a fourth order low pass on the second 1501 at 700hz, and a second order high pass on the 476be at 700hz. Could you possibly explain a little more?

In my case, room gain is not a great issue (old leaky historic building) and the step response on the 4338 works well. But given that I don't have the efficiency constraints of the 045be to work around, I was thinking of doubling up to gain a little system sensitivity and to find a little extension. Is that a silly idea?

Zilch
01-13-2007, 07:21 PM
The really cool thing about Everest II is that both those 1501AL's are rolling off at 12 dB/octave rather than the usual 18 dB/octave or 24 dB/octave and that means they sound nice and strong in a typical listening room.Is it closed-box?

If so, I'm REALLY stupid for not noticing that.... :banghead:

johnaec
01-13-2007, 07:27 PM
Is it closed-box?I believe it's got a couple ports in the back. See pic: http://audioheritage.org/vbulletin/showpost.php?p=130188&postcount=77

John

Mr. Widget
01-13-2007, 08:55 PM
In other words, given no cost or space restrictions, would you team the 435be with 2 x 1500AL or similar and if so why?
During my experiments with Project May, I discovered that using a pair of 1500ALs in my room the bass was significantly better sounding... it was deeper and fuller sounding when using a pair per side over a single 1500AL... I tried bumping up the EQ on a single 1500AL... this gave me a similar measured response to the dual 1500ALs, but subjectively the sound just wasn't as awe inspiring.

While at CES, I asked Greg Timbers about this... he agreed that a pair of 1500ALs is magical, and that is why the DD66000 uses a pair. When I asked why the pair sounds better than the EQ'd single woofer, Greg shrugged his shoulders and said, I guess you just can't compensate for cone area.

I have no experience with the 1500AL in a smaller room, but in a large room, I would only consider a pair of them. It will require 9 cu ft of enclosure, and that is why I am not using them currently, but the sonic virtues of the pair makes me question my desire to limit the physical size of the loudspeaker. If I could physically fit a pair of 1500ALs in each of my speakers, I would use them as nothing else I have heard sounds as good.


Widget

merlin
01-14-2007, 04:57 AM
Thanks Widget,

I presume that you were using the two seperate 4.5 cu ft boxes - not a single 9 cu ft box? Were you using them side by side ala Everest? I'm thinking the experiment is practical using four 4.5 cu ft boxes, but less so with 2 x 9 cu ft.

Mr. Widget
01-14-2007, 11:05 AM
Yes, they were in two 4.5 cu ft boxes. For Project May we had them stacked vertically in a quasi MTM setup.


Widget

merlin
01-15-2007, 04:38 PM
Thanks Widget. I have great hopes for the two way project. Looking to upgrade these little babies

http://i6.photobucket.com/albums/y225/airwise/KICX0705.jpg