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Hey RBP [message #33011] Thu, 22 March 2001 01:29 Go to next message
bean_counter is currently offline  bean_counter
Messages: 8
Registered: May 2009
Esquire
Ready to think about L200's yet?

Here's what I've got:

LE-15B's in 4.5 cu ft vintage furniture cabs; sliding bottom panel cut-out (cab is on legs) for adjustable venting

2420's on Edgar round horns (800hz cross)

3131A crossovers (huge! out of 4331A monitors somebody parted out)

My main question is about proper venting for the 15B. WAF dictates that the cabs stay, but venting can be adjusted. marc g. told me the stock venting was 2 4" dia. tubes, 7.5" long. Seems like a LOT of venting for a really loose woofer. I've narrowed the gap on the sliding panel quite a bit to focus things a bit more.

Anyway, any hints would be very much appreciated. I'm driving them with PP 6B4G's, and they have GREAT potential if I can tighten up the bass a bit.



I am with you! [message #33013 is a reply to message #33011] Thu, 22 March 2001 01:40 Go to previous messageGo to next message
RBP is currently offline  RBP
Messages: 26
Registered: May 2009
Chancellor
Gut feeling is (2) 4" Ports about 9" long.

Let me number crunch and see what this looks like.

I think the above will get you a solid -3dB at 21hZ...-2 at 24 hZ and level at 28hZ.

This is strictly off the top of my head. I do prefer rear ports, 3 12th's the way from the top of the rear baffle. Space them symentrically side by side.

Now I will number crunch to see what this looks like on paper.

Your take Wayne?? [message #33026 is a reply to message #33013] Thu, 22 March 2001 17:08 Go to previous messageGo to next message
RBP is currently offline  RBP
Messages: 26
Registered: May 2009
Chancellor
I cannot find the parameters on the L15B JBL driver...and have used them for years. The above port sizes for a 4.5 cu ft. will give him some great low bass and punch, without that nasty 47hZ "bomp" I feel.

He will need 2" of fiberglass on all walls and the rear.
Could you run the numbers and see where it lays?

Appreciate it.

Re: LE15B data seems to be non-existant [message #33027 is a reply to message #33026] Thu, 22 March 2001 18:25 Go to previous messageGo to next message
bean_counter is currently offline  bean_counter
Messages: 8
Registered: May 2009
Esquire
I tried asking at audioheritage last fall and they didn't have anything, either.

Someday when I have the time, I'll take them to a speaker shop in Chicago to get measured. But that means taking them out.... hmmmm, not so sure now....

Think they'll go that low?! I cranked up the Saint-Seans organ concerto, and it seemed to go aaaallll the way down. My amps only do 20hz, tho.

Re: LE15B data seems to be non-existant [message #33028 is a reply to message #33027] Thu, 22 March 2001 18:44 Go to previous messageGo to next message
RBP is currently offline  RBP
Messages: 26
Registered: May 2009
Chancellor
Q: Do I think they will go that low?

Big time. I have heard them in multiples of 3 hit 15hZ as fat as anything avalible.

My port sizes are not scientific, but artful.

You try them, you will find they will correct a lot of problems, and you will have the serious bottom provided the internal dampning material is there.

I'll look for it tonight [message #33031 is a reply to message #33026] Thu, 22 March 2001 19:29 Go to previous messageGo to next message
Wayne_Parham is currently offline  Wayne_Parham
Messages: 123
Registered: May 2009
Master
I'll look for it tonight. Right now, I'm not at the desk with my files, but I'm pretty sure I have at least T/S specs.
LE-15 T/S parameters [message #33038 is a reply to message #33026] Fri, 23 March 2001 00:47 Go to previous messageGo to next message
Wayne_Parham is currently offline  Wayne_Parham
Messages: 123
Registered: May 2009
Master

JBL LE15A

fs 20
Qts 0.21
Vas 26.0
Eff 2.6
Pe 100
Xmax 0.16
Dia 13.2
Qms 5.5
Qes 0.22
Re 8.8
Le 2.2
Bl 22.0
Mms 97
flux 0.90

Re: nope, LE-15B's have a cloth surround [message #33040 is a reply to message #33038] Fri, 23 March 2001 07:09 Go to previous messageGo to next message
bean_counter is currently offline  bean_counter
Messages: 8
Registered: May 2009
Esquire
rather than the usual foam. Pro designation was 2216.
Bean...Go with the Ports I recommend. [message #33045 is a reply to message #33040] Fri, 23 March 2001 14:42 Go to previous messageGo to next message
RBP is currently offline  RBP
Messages: 26
Registered: May 2009
Chancellor
It will sound musical.
Re: I'll give it a go this weekend [message #33049 is a reply to message #33045] Fri, 23 March 2001 17:07 Go to previous message
bean_counter is currently offline  bean_counter
Messages: 8
Registered: May 2009
Esquire
spouse permitting, of course ;-)
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