K-77-M -- how low will it go?

[Tom Mobley]

the Deaninator speaks truth once again. IMHO, YMMV, all that cop-out jazz.

[Deang]

Even though I only understood about half of what he posted, and didn't agree with half of the half I understood -- this was a better place with him then it is without him.

[Marvel]

Plus, I liked the two ten inch DRs for the mids on teh Khorns. That is so cool.

Dean,

Are you still using those Erse coils in your crossovers? For the woofer one anyway.

[Deang]

Crazy mod, I bet it sounds great. I guess that's what we call thinking out of the horn.

In the ones I build for sale I use the smaller Erse iron cores: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-556.

I use them because the DCR is the closest to the stock Klipsch unit. When I build for myself I use the Erse Super 'Q'. The DCR is lower, and in my Klipschorns it brings up the midbass a little -- which works good for my music.

[Marvel]

Are you leaving that at 2.5 mH or are you unwinding some to get the 2.4? Probably not enough of a difference to really tell.

[Deang]

Bruce, 2.4mH, 14AWG is what Al used in the ALK. I'm pretty sure he used this because Solen does not offer a 2.5mH, 2.4mH is within 4% of the target value, and in a first order filter section it means absolutely zero.

[Marvel]

Kinda what I thought. The Solen 2.4 solid conductor is now almost $40. I think I'll try the Erse.

Time to get off here for a while. I'm in Valparaiso, packing the

youngest out of his dorm room and heading back to Georgia. 600 miles up

yesterday and heading back today. This is making me feel old. Keep

thinking I'll stop and see Michael on the way through Indy, but we're

usually in a hurry.

[Guest " "]

whats the verdict on "how low will it go".

3500 or 3000?

[Trey Cannon]

How about we let you know after this weekend .....

[Deang]

[Trey Cannon]

Well it looks like this will have to wait for a bit...some things have come up forcing me to hold of on the testing I was to do.

My plan is to test as many of each type that I can and show all the data.

The one thing everyone must remember is that as you look at the drivers as a whole one can pick a Low f cutoff area, But each driver will be a bit different. As you produce tons of units you can hold to a tight tolerance.

When dealing with Used or old drivers you never know what you have unless you test each one and build the network for just that driver.

It should be fun to find how this turns out.

[Guest " "]

while we wait...I came across a copy of the following tech data in an old ev st-350 "draft" tech data sheet. I say draft because the whole thing looks typed up, has notes written on it, notations of where to insert photos, a few charts, graphs, and lab results, condition of test, etc...written up by a fellow named Keele in Oct 10, 1973.

the data is for the st-350, but the diaphram is the same used in an ev t-35, ev t-350, ev tw-35, k-77-m, k-77, speakerlab ht3500, etc.

voice coil diameter - 1.004"

DC resistance - 5.8 - 6.4 ohms

Nominal impediance - 8 ohms

Wire lenth - 76.9 inches (i am assuming this is coil wire lenth)

Total Mechanical Moving Mass - 0.22 grams

Voice coil sub-assembly mass 0.07 (I am assuming this is the tube the wire is rolled on)

Nominal diaphram resonance - 2,800HZ

[ajsons]

I built my SK clones in 1986, with the t35 crossed at 3500hz (EV's favorite xover point with an X36), but mine was 12db/oct. I only changed over to ALK's about two years ago. The spec sheet says usable low freq limit of 3500.