Can You Design Me a Crossover That:

[toddalin]

Can better integrate the 2235 with the LE175 on an HL-91 with an 075.

Changing out the 130As to 2235's left a "hole" in the area between 500 - 1,000Hz. To me, this is perceived as a muffling of peoples voices.

I am currently using an N1200/N8000. I would like to crossover the woofer to the horn at about 800 Hz. This should be high enough to let the horn operate within its range while reducing the size of the "hole." A two-way that retains the N8000 would work fine. All components are 8 ohm.

Thanks

[speakerdave]

You might be able to build one yourself. You could begin by looking at this thread about the 3133, the crossover for the 4333/L300. Your list of equipment is similar, although there are differences.

http://www.audioheritage.org/vbullet...highlight=3133

I'm not sure if there is a free crossover designing service available here. I think there probably would be help available if someone started out on his own and ran into some glitches, but that's just my guess. Our new forum is called DIY, not DIFM.

David

[John]

Our new forum is called DIY, not DIFM.

David

[toddalin]

Thanks for the link. I should be able to adapt the L300 network.

There are limits to DIY and I would still be physically building the crossovers. I just figured that if the design was out there, why reinvent the wheel? Even with the L300 design, I would probably just use the two-way section and still retain the N8000s just to fill in the hole in the back of the cabinets.

[edgewound]

Todd...

You should probably look for LE85/2420 or 2425/6 if you want the midrange to be clean and trouble free to work with a network such as for an L300. I'm afraid you'll find the LE175 won't be up to the task...it was meant to work with 130A or D130. Just my opinion...might save some future headaches.

[toddalin]

Edge, it's certainly a future possibility, but three nice LE85's don't come cheap and and HL92's are scarce. (Wasn't easy to get wife to go for $1,050 just to redo the four woofers. )

I assume that I can use higher wattage resistors than indicated (e.g., substitue a 25 for a 20 watt resistor) so long as I retain the proper resistance.

[speakerdave]

I just figured that if the design was out there, why reinvent the wheel?

Indeed. My wisecrack was a little out of line, but I couldn't resist. I should talk, anyway. The whole crossover thing has given me the hesitation blues.

Even with the L300 design, I would probably just use the two-way section and still retain the N8000s just to fill in the hole in the back of the cabinets.

It seems to me Ian has suggested that cascading crossovers, although apparently JBL-recommended practice in the past with prebuilt units, can involve unnecessary compromises when building from scratch. In the old charts ('70's) JBL treats the 175 and 85 compression drivers as interchangeable vis-a-vis horns and crossovers for HF and the 075 and 077 also when used for UHF. It might be better to go for the whole 3133, either using the charge-coupled or bypassed version. (And then pay for the parts by selling the N8000's on ebay.) Anyway, that would be a specific question I would post for the filter wizards.

David

[speakerdave]

Todd...

You should probably look for LE85/2420 or 2425/6 if you want the midrange to be clean and trouble free to work with a network such as for an L300. I'm afraid you'll find the LE175 won't be up to the task...it was meant to work with 130A or D130. Just my opinion...might save some future headaches.

The 130A and the D130 both have much higher output than the LE15 or 2235. The sensitivies of the 175 and the 85 are listed as identical. The differences would be in UHF extenstion. Either is adequate when crossed over to a supertweeter.

David

[speakerdave]

. . . and HL92's are scarce.

I have a pair of H92's sitting in my garage, black, crinkle paint, nice and clean; one of the foilcals has gone missing. I'm afraid I have $175 into them, but they're yours for that plus transportation if you want them.

David

[edgewound]

The 130A and the D130 both have much higher output than the LE15 or 2235. The sensitivies of the 175 and the 85 are listed as identical. The differences would be in UHF extenstion. Either is adequate when crossed over to a supertweeter.

David

I understand...but my thinking is that the bigger motor will better handle the lower crossover point and the transients that go with home theater sound tracks. Like I said...just my opinion. Also 2425's are still reasonable on ebay, etc.

[speakerdave]

. . . . my thinking is that the bigger motor will better handle the lower crossover point and the transients that go with home theater sound tracks.

Could be true.

Either driver will be better off with the longer horn at 800 Hz.

David

[toddalin]

Could be true.

Either driver will be better off with the longer horn at 800 Hz.

David

If I were to change, I would need at least 3.

To be honest, I had the woofers out of the L200 cabinets the other day and with the LE175/HL91, there only appears to be about 1.5" from the back of the driver to the back of the cabinet. (I actually have a piece of styrofoam wedged between the driver and cabinet back.) An HL92 is reported as being 3" longer than an HL91 and is reported to be used in this cabinet..., but I can't see how. Add to that that the LE85 has a bigger diameter and because of its angle, this also affect mount depth, how could it fit???.

[norealtalent]

Partial

...An HL92 is reported as being 3" longer than an HL91 and is reported to be used in this cabinet..., but I can't see how. Add to that that the LE85 has a bigger diameter and because of its angle, this also affect mount depth, how could it fit???.

I believe HL92 is 4" longer. It will not fit a stock L200 cab.

[Zilch]

No go, Todd. That's the problem.

And punchin' the driver out the back is, ummmm, well, you know....

Upgrade to LE85/2420 later.

[edgewound]

Maybe a compromise solution would be to crossover the HL91 at 1000hz with 3rd or 4th order Linkwitz-Riley crossover...Maybe Giskard can advise on this. I read another thread about the OASR waveguide being useable down to 750-800hz, so why shouldn't the H91 be ok at 1Khz with steep enough slope?