515 frequency response and crossover question

Yesterday after a listening session with my Simplex W's, I unloaded the third cabinet, repaired the one damaged 515 paper surround per Bill H's instructions, and loaded the 515's into cabinets designed for 604's. Amazing how the screw holes lined right up... :D

Anyway, I'm going to pair these up with some combo of Horn/compression driver. Most likely, I'm going to remount my 1005'bs on new boards that will fit on top of these cabinets, and then just use a simple high pass filter to protect the drivers. I'll probably start with a set of 288-16G's and see how they sound....

Anyway, the question then becomes how to supply the 515's. Do I need to use any sort of low pass filter, or can I let these roll off naturally. It would be kind of interesting to use a pair of 420-A's in these cabinets also, but that's a project for another day....

If I do need to add a low pass filter, where should I cross these over? Any ideas for a combined network that I could perhaps build without having to take out a second mortgage?

I do have a set of JBL L-19 crossovers lying around, but their crossover point is way too high at 2.5KHz.....

Yeah I know Behringer, but it's not in the cards right now as I save for a Mac tube piece....

TEXT BOOK CROSSOVER

Second Order (12db/octave) Two-Way Crossover

High Pass Impedance 16 OHMS
Low Pass Impedance:16 OHMS
Frequency 500HZ

C1 14MF
L1 7.2MH
C2 14MF
L2 7.2MH



http://www.hostboard.com/forums/hbmc.../2009/03/1.gif


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Maybe I should ask this a different way....

If one wanted to set up a 515/1005b/288-16G two way speaker system, where would the best crossover frequency(s) be?

Are there any specs for the 515 to be found?

Can anyone guess where the breakdown point would be on the 515?

Can I safely assume that I would be under served by running the 515 full range with just a high pass on the 288-16G?

TIA.....

New 515= Altec - 515 - 15" Loudspeaker
515g= 515G
I am seeing that the highest recommended crossover frequency is 2500Hz. I would assume that your multicells will come in much lower than that so an expedition into experimentation with lower crossover points would net good results.

You state that you're saving for a Mac setup but if you could squeeze less than a hundred out of somewhere, the Behringer CX3400 might be an efficient use of capital. I use one with 416b's and 811's and it does a pretty good job.

I hear you.... :D

However, if active crossover is the ticket, I was going to wait for a DCX-2496 to walk into my life.

However, I decided to go to the source, and called Steve at GPA. Even he was unable to lay his hands on a 515 spec sheet, but his advice was to cross over at 800 Hz or so because of some of the driver characteristics w.r.t. vocal reproduction.

So 800Hz it is....for now...

Assuming we're talking about a paper surround 515, it's rated 25 Hz Fs, 30-1 kHz BW, 35 W/50 W, but with almost no Xmax it quickly goes nonlinear down low if not horn loaded and/or driven with a high output impedance and designed for a 500 Hz/2nd order XO point. When new, its response was very close to the 515B except for a bit more top end 'sizzle', so a higher XO point will in theory require a higher slope order to keep from unduly 'coloring' the HF horn's output, though as always it's a personal preference 'thing' in HIFI/HT apps.

WRT running it wide open, I've read of some folks liking it with the HF horn just capped off 1st order way up high, but not me. Still, worth trying since swapping out cheap caps to see if any XO point works for you is easy enough. FWIW, the women liked a 515B with a 802 mounted to a 3/4" baffle thickness horn capped off at ~5 kHz, so no wonder there's often a 'battle of the sexes' over what sounds good.

GM

No affiliation.

BBE DS26 SPEAKER MANAGEMENT SYSTEM PROCESSOR DS-26 SALE - eBay (item 300295012939 end time Mar-20-09 20:42:40 PDT)

I steered another member into one of these a while back, it's a little cheaper and a little easier to use than the Behringer, and the sound quality is right on par. It's also a great alternative for those folks who can't seem to allow themselves to own anything bearing the Behringer name. The Behringer allows for removal of the rack ears for those who want to avoid "industrial" loking gear in their system. I like them both and don't really have a preference.

Thanks Tom, that's strong praise, considering it was your 2496 that got me interested in the first place.

Will the BBE do stereo three way crossovers? At some point I was thinking about adding some sort of super tweeter....

I'm going to post the exhumation pix here as I go and have time. Might as well do it where the members will really appreciate them, and not try and tell me how JBL gear is better.... :P

Really if it wasn't for the slight splatter of theater screen paint, these babies could pass for new. I also need to clean up the horns. Everything has about an 1/8" coat worth of dust spanning 50 years of service on them....

While I round up some inductors, I may just try these full range with a simple cap/high pass filter in place. I'm only going to throw a few non-sand watts at them, so I'm not thinking I'm going to hurt anything....

Quote:

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Will the BBE do stereo three way crossovers?

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Yes indeed. The model number "26" signifies a "2 in 6 out" maximum configuration. They also offer a DS-24 and DS-28, 2 in 4 out, and 2 in 8 out as their model numbers would imply. I haven't looked at the other two models close enough to say for sure that the only difference between them is the number of output channels and possible configurations, but it's probably a fairly safe assumption.