Building options - what to do?

[Louis]

Hi.

I have over the years collected som different JBL parts - and now i have started thinking of building something with. I am pretty good with Wood, building, venering etc. But the whole "what Works - and what do not" - i am not that good with.

I have some diffferent parts.
Tweeters
2403 alnico
2402 alnico
2402H
2405H

Mids:
2420 with h92 and lenses
2440
2440 with 2441 diaphrames
10" 2123H
Two pairs 2397 with 2328

Woofers.
2 pairs of le15a 8 ohms
Le15H
2215a
Pr-15

To i use my le15H with 2397/2440 and 2307. I a 150 liter enclousere, Two ported. Crossovers are 3110/3205. I am very happy with the way it sounds but i have this idea in my head and I do not know if It's a good idea. I would like to build a 4-way system with 2 Le15a om each side with 2123h as mod the 2397/2440 as high and 2303 as ultra high. I am thinking s enclousure arround 200-250l. Plus maybe 16l for the 2123h. Horn and tweeter will lay on top.

Does this just sound stupid - or could this be a well sounding speaker ud done right? I do not know what to do with crossovers yet - i will have to have them build.

Any ideas, toughts, do's and dont's will be appreciated.

Regards Louis

[engineerjoe]

IMO when they (JBL) build crossovers, the already picked components are tuned in. They'll dial something back if it out performs something else. Now days you can easily do this with electronic DSPs.
You may find that you can even compensate for something lacking in your cabinet design for a given driver or the driver(s) itself.
There are some good examples on this site with some or most of these components in use. I myself, preferred the sound of the slot tweeters, although later models of 2" JBL drivers with correct diaphragms don't need them as much. I myself again, prefer a good mid speaker in the lower mid vocal range over a driver in close proximity use. I'm describing something like 800 to 1200 HZ especially.
I can go on and on but what's important is to know what you like, and what you want to achieve with these components. There remain good performers and should do a good job for you if they are utilized correctly.

[Dr.db]

Your idea isn´t stupid at all.
Actually a very high regarded company has build a similar setup:
http://www.westlakeaudio.com/Speakers/Professional_Series/hr-1.html

I myself am thinking about this setup for quit a while too.
A 10" mid-woofer will match the dispersion-characteristics of the 2397-horn at the crossover-freq. very well. That should translate into a smooth transition between these two soundsources. By using a 10"-mid-woofer you can aim for a higher crossover-freq. on the horn, which reduces distortion by a lot!

I would use the following of your components:
- JBL 2403 or 2405
- JBL 2441 on 2397
- JBL 2123
- JBL LE15H (2 units)

I would use the following crossover-freqs.:
- 10khz
- 1,2khz
- 0,3khz

Do a search on the 3155 equivalent crossover.
This should work well for the top 3 units. Go active between 10" and 15" woofers...

[Dr.db]

http://www.westlakeaudio.com/Speakers/Professional_Series/hr-1.html

Using this baffle-layout comes with another advantage compared to a conventional tower-speaker:
These horizontally designed boxes are usually placed on a pedestal to raise the midhorn to the right listening height.
Doing so both 15" woofers are raised about 1 foot off the floor. The interaction between the woofers and the floor should give a more precise bass, as the modal response is less affected.
Raising woofers off the floor should affect the negative effects of the room-acoustics less.

[1audiohack]

Hi....I would like to build a 4-way system with 2 Le15a om each side with 2123h as mod the 2397/2440 as high and 2303 as ultra high. I am thinking s enclousure arround 200-250l. Plus maybe 16l for the 2123h. Horn and tweeter will lay on top.

This is what I would use also. :)

Barry.

[Louis]

Your idea isn´t stupid at all.
Actually a very high regarded company has build a similar setup:
http://www.westlakeaudio.com/Speakers/Professional_Series/hr-1.html

I myself am thinking about this setup for quit a while too.
A 10" mid-woofer will match the dispersion-characteristics of the 2397-horn at the crossover-freq. very well. That should translate into a smooth transition between these two soundsources. By using a 10"-mid-woofer you can aim for a higher crossover-freq. on the horn, which reduces distortion by a lot!

I would use the following of your components:
- JBL 2403 or 2405
- JBL 2441 on 2397
- JBL 2123
- JBL LE15H (2 units)

I would use the following crossover-freqs.:
- 10khz
- 1,2khz
- 0,3khz

Do a search on the 3155 equivalent crossover.
This should work well for the top 3 units. Go active between 10" and 15" woofers...

Thanks for the very nice reply. I do not have two pairs Le15H only A's.

I would like. If prossible to do the crossovers 100% passive. But if it Works a lot better i would have to find myself another poweramp for the active crossover.

The crossover frequencys are what i was thinking as well.

My idea is stolen from Westlake - which i have never heard with my own ears:)

[Louis]

http://www.westlakeaudio.com/Speakers/Professional_Series/hr-1.html

Using this baffle-layout comes with another advantage compared to a conventional tower-speaker:
These horizontally designed boxes are usually placed on a pedestal to raise the midhorn to the right listening height.
Doing so both 15" woofers are raised about 1 foot off the floor. The interaction between the woofers and the floor should give a more precise bass, as the modal response is less affected.
Raising woofers off the floor should affect the negative effects of the room-acoustics less.

This layout is pretty close to what i was think. Myabe i will raise the 2123 a bit to bring the woofers closer (just to save some Spaces).

[Dr.db]

You are correct, I didn´t notice there is just one pair of LE15H´s. Feel free to use the LE15A´s instead.

If you use very low resistive coils/inductors on the woofers, it should be possible to run it completly passive. I guess everyone on this forum will still recommend an active crossover on the woofers... I´m not an expert on this one, so I´m happy to hear comments by others.

If Louis would use coils/inductors with a DCR as low as 0,1ohm on the woofers, what´s the drawback :confused:

[Louis]

You are correct, I didn´t notice there is just one pair of LE15H´s. Feel free to use the LE15A´s instead.

If you use very low resistive coils/inductors on the woofers, it should be possible to run it completly passive. I guess everyone on this forum will still recommend an active crossover on the woofers... I´m not an expert on this one, so I´m happy to hear comments by others.

If Louis would use coils/inductors with a DCR as low as 0,1ohm on the woofers, what´s the drawback :confused:

If it's Better sounding i will go witch active crossovers for the woofers.

[Flodstroem]

I do not have two pairs Le15H only A's.

Well, I have a pair of LE15Hś for sale (here in Norway). Re-coned last summer (JBL original). If you are interested........ :D

[jblgo]

If it's Better sounding i will go witch active crossovers for the woofers.

An option is to use a plate amp which includes adjustable low pass filter, Wire the woofer in parallel.


jblgo

[Louis]

Well, I have a pair of LE15Hś for sale (here in Norway). Re-coned last summer (JBL original). If you are interested........ :D


I may be. I like to have options:)

[Louis]

An option is to use a plate amp which includes adjustable low pass filter, Wire the woofer in parallel.


jblgo

If i should use a completly passive crossover for this project are there any good options to copy? Like the 4355 maybe?

[Earl K]

If i should use a completly passive crossover for this project are there any good options to copy? Like the 4355 maybe?


I'm pretty sure that the network for the 4355 requires biamping the system.

Have you looked at that crossover ?

You should count on biamping and then using the rest of that network ( assuming the use of comparable parts > the 2123H has been identified as comparable to the 2202H in the 4355 ).

:)

[Louis]

I'm pretty sure that the network for the 4355 requires biamping the system.

Have you looked at that crossover ?

You should count on biamping and then using the rest of that network ( assuming the use of comparable parts > the 2123H has been identified as comparable to the 2202H in the 4355 ).

:)


Thanks for your reply. I am pretty shure you are right. I didn't know that was a crossover the requred biamping - i mostly know of the 4343 which My Friend owns.