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barkingdog
10-28-2005, 11:04 AM
Boy, I wish I had been registered here before I started buying stuff .... well here goes ....

I've been picking up components for some studio monitors I'd like to build. The plan is, for each cabinet :

LF - 2235H
MF - 2425J
HF - 2405

Bi-amp using Bryston active crossover (800 Hz) and two Bryston 4B's. Use a 3105 (bought or custom made) crossover between the 2425J's and 2405's. Probably an L-pad on the mids (?). 5 cubic foot 3/4" MDF (is Baltic Birch better? That's what I've been using for PA cabs) boxes with two 4" ports at 11" length.

My problem is that I jumped on a "Buy It Now" (yes, I'm Mr.Impulsive) for a pair of L91 lenses. From what I've read since, these were meant to be used with H91 horns which are meant for 1200 Hz. Being a relative newbie, I didn't realize that the horn/lens combos were for specific frequency ranges:banghead: . So, from what I've read since, what I should be using is an H92/L92 combination.

This may be a stupid question but will the L91's be ok with an H92 horn?

Does anyone see other design flaws here?

By the way, what application are 2301 horns meant for?

This is a great forum. Looking forward to meeting y'all.:bouncy:

Cheers,
James.

Uncle Paul
10-28-2005, 11:38 AM
"This may be a stupid question but will the L91's be ok with an H92 horn?"

L91 will work OK and was the lens used on the L300/4333, which it looks like you are modeling your speakers on. Look through the library for info. The L300 brochure has cross sections and dimensions if you want to replicate the cab.

3/4" MDF will work just fine.

I'd make the passive crossovers. You can use much better components than the originals, and it will be far cheaper than buying 3105's.

I had a similar system many years ago and it was awesome. Only difference (other than choice of electronics) was I ran Transylvania Tubes instead of the horns. I don't think you will be dissapointed.

Spend time browsing the forums and make use of the search functions. There is an incredible amount of information here.

barkingdog
10-28-2005, 11:58 AM
"Only difference (other than choice of electronics) was I ran Transylvania Tubes instead of the horns. I don't think you will be dissapointed."

Uh, I'm going to go out on a limb here and assume that "Transylvania Tubes" are not the ducts inside the canine teeth of vampires, right?

I did a search on them but didn't find much. Can you tell me what they are?

Thanks again.

Ian Mackenzie
10-28-2005, 03:07 PM
You might be barking up the wrong tree...sorry..could not resist.

Consider a 4430 clone, just score your self a 2344 horn and put your 2405 on top for good measure..The 4430 is a vast improvement over the 4330/4333.

Lord Zilchtermeister is the Lansing 4430 guruarmaamama around here. I am sure he would be glad to offer assistance.

But if you dare, score a JBL 2118 or a 2123 and join the land of JBL legends for a 4343-4344.

Ian Mackenzie
10-28-2005, 03:15 PM
Actually I think its is about time The Great Zilchster was put on notice to add a uhf device to the tried and proven but tired 4430.

:)

scott fitlin
10-28-2005, 04:27 PM
Boy, I wish I had been registered here before I started buying stuff .... well here goes ....

I've been picking up components for some studio monitors I'd like to build. The plan is, for each cabinet :

LF - 2235H
MF - 2425J
HF - 2405

Bi-amp using Bryston active crossover (800 Hz) and two Bryston 4B's. Use a 3105 (bought or custom made) crossover between the 2425J's and 2405's. Probably an L-pad on the mids (?). 5 cubic foot 3/4" MDF (is Baltic Birch better? That's what I've been using for PA cabs) boxes with two 4" ports at 11" length.

My problem is that I jumped on a "Buy It Now" (yes, I'm Mr.Impulsive) for a pair of L91 lenses. From what I've read since, these were meant to be used with H91 horns which are meant for 1200 Hz. Being a relative newbie, I didn't realize that the horn/lens combos were for specific frequency ranges:banghead: . So, from what I've read since, what I should be using is an H92/L92 combination.

This may be a stupid question but will the L91's be ok with an H92 horn?

Does anyone see other design flaws here?

By the way, what application are 2301 horns meant for?

This is a great forum. Looking forward to meeting y'all.:bouncy:

Cheers,
James.I truly believe you might be better off with a slightly smaller amplifier on your mid horn/tweeters! The 4B is very powerful, and I would have used a 3B on your higher frequencies. Its easier to drive, and will give you a more relaxed sounding mid than the 4B!

toddalin
10-28-2005, 05:09 PM
My problem is that I jumped on a "Buy It Now" (yes, I'm Mr.Impulsive) for a pair of L91 lenses. From what I've read since, these were meant to be used with H91 horns which are meant for 1200 Hz. Being a relative newbie, I didn't realize that the horn/lens combos were for specific frequency ranges:banghead: . So, from what I've read since, what I should be using is an H92/L92 combination.

This may be a stupid question but will the L91's be ok with an H92 horn?

This is a great forum. Looking forward to meeting y'all.:bouncy:

Cheers,
James.

From JBL Loudspeaker Components (1975):

HL91 Horn/Lens, An exponential horn having an optimum cross-over frequency of 500 Hz and a 10-inch slant-plate acoustic lens for use with the LE175 and LE85 compression drivers.

HL92 Horn/Lens, A longer cast aluminum horn with optimum cross-over charactristics at 800 Hz for use with the LE175 and LE85 compression drivers. Utilizing a 10-inch slant-plate lens, the additional length of the horn offers smoother performance and is preferred if enclosure depth is adequate for mounting. (HL92 is 10-3/4")

Always seemed to me that a longer horn plays to a lower frequency, but that's not what this says.

I do know that the typical HL87 is 1" shorter than the HL91 (6-3/4" vs 7-3/4") and this horn/lens was typically used on the LE175 with a 1,200 Hz cross-over. (But there was variation as I have an HL87 in my center channel that is the same length as the HL91.)

Zilch
10-28-2005, 05:21 PM
They subsequently "discovered" that HL91 isn't worth a whit below 800 Hz.... ;)

Alex Lancaster
10-28-2005, 05:31 PM
:) The lens is the same.

Uncle Paul
10-28-2005, 07:45 PM
"Only difference (other than choice of electronics) was I ran Transylvania Tubes instead of the horns. I don't think you will be dissapointed."

Uh, I'm going to go out on a limb here and assume that "Transylvania Tubes" are not the ducts inside the canine teeth of vampires, right?

I did a search on them but didn't find much. Can you tell me what they are?

Thanks again.

Here you go, they are a type of waveguide. Think of it as a pipe organ tube with a varying length. They need to be tilted back about 30 degrees.

slxrti
10-28-2005, 10:53 PM
Boy, I wish I had been registered here before I started buying stuff .... well here goes ....

I've been picking up components for some studio monitors I'd like to build. The plan is, for each cabinet :

LF - 2235H
MF - 2425J
HF - 2405

James.
The HL91/92 horn was conceived in early era of audio. In my opinion, they

throw music at you, like a spot light. The 2344 horn may look odd, but it can be a very accurate device.



Add a mid bass driver, such as a 2123/ 2118. The reason is the 2235 can make it to 1.2k but, the lower midrange can sound unnatural.



The 2235 can be used a ported box, but it also works well with a passive radiator. A passive in theory would ring more than a vented system, but to my ears they sound more realistic/ natural. It was used in the sr8 system of the 60’s.



slxrti

yggdrasil
10-29-2005, 04:39 AM
Together with friend of mine we are playing with a design with the same drivers.


We are planning crossover points at 6-700Hz and 8-10KHz. After a project with Altec 806/811 combo (http://audioheritage.org/vbulletin/showthread.php?t=4950) I really got my eyes opened to large horns.

Anyway we have started forming a large sectoral horn with Tractrix contour.

As stated by both Ian Mackenzien and slxrti a 4-way is beautiful if you choose the small exponentials. Or even rebuild the 4430 as a 4-way (Zilch - thats a double 2-way!)

Lancer
10-29-2005, 05:58 AM
Lord Zilchtermeister is the Lansing 4430 guruarmaamama around here.:rotfl: