Isophon KK8, KEF T27

[guitarded]

Anyone know where I can find FR and impedance graphs for these vintage tweeters?

 

[planet10]

dave

 

[guitarded]

Thanks for the quick response Dave!
Sure wish I could find some graphs that I could SPL Trace.

P.S. Don't know if you remember me. I bought some PA gear from you in the early 80's. Glad to see you're still into audio. Gonna have to check out your speaker designs.

 

[planet10]

P.S. Don't know if you remember me. I bought some PA gear from you in the early 80's. Glad to see you're still into audio. Gonna have to check out your speaker designs.

Wow -- a blast from the past. You'll have to remind me of the details

Shortly after the pro buisness (which was a financial bust), i went into computers and was just a passive audio guy for about 15 years, but that wasn't a satisfactory state of affairs and i have come back with a vengence. I'm just about to start putting my toes back into the pro stuff with Maria.

I have some T27 FR, but they are with the XO in line (part of a paper on the XO in teh 104aB) -- i can dig that out if you think it useful. Attached is an impedance curve from a set i sold on eBay.

dave

 

[planet10]

I don't know where this one came from, or the conditions of measurement, but it is a T27 FR plot.

dave

 

[guitarded]

Dave, Details: 3 Bryston amps, Biamp board, Shure 57 mic's + stands. remember?
Even farther "blast from the past", I built some b139 transmission lines from your plan back in 1977. I still have them!
Anyway, Thanks for the graphs. I'm sure they will be helpfull.
I'm trying to design some HT speakers and was hoping to utilize some of the vintage drivers I have hibernating in my closet.
I haven't messed with audio in the last 25 years. Hopefully this project will rekindle some passion.

 

[planet10]

Details: 3 Bryston amps, Biamp board, Shure 57 mic's + stands. remember?

The heart of the PA/// 2 4Bs a 3B and a biamp XO?

Even farther "blast from the past", I built some b139 transmission lines from your plan back in 1977. I still have them!

I sold a zillion KEF drivers back in the late 70s, and have seen almost none of them, so everyone must be keeping them. Still using the woofer?

dave

 

[Rolf Zetterberg]

Isophon has a huge archive on older drivers.Maybe you'll find it there:
http://www.lup-berlin.de/archiv/Katalog/index.html

 

[Geoff]

T27A datasheet with response graph etc.

 

[guitarded]

Dave, Biamp (brand name) was a 16 channel mixer.
I still have the B139's loaded in the TL's. My current speakers are Quad ESL's and the B139's are a little too sluggish to mate with them. If I remember correctly, I couldn't get a smooth transition to the fast ESL's.
Thanks Rolf and Geoff !!! I might have enough now to create .frd and .zma files.
Thanks again for your help! Muchly appreciated! You guys are awsome!

 

[planet10]

Biamp (brand name) was a 16 channel mixer.
I still have the B139's loaded in the TL's. My current speakers are Quad ESL's and the B139's are a little too sluggish to mate with them. If I remember correctly, I couldn't get a smooth transition to the fast ESL's.

I know the board. The amps you got would have been one of the 2 racks we had for driving the PA. Each of the racks also had a biamp XO... wonder if you got that too

dave

 

[MRupp]

I sold a zillion KEF drivers back in the late 70s, and have seen almost none of them, so everyone must be keeping them. Still using the woofer?

Noticed this thread by accident: I still have a set of T27, B200 SP1039, and B139 passive radiators from my first (and only) DIY speakers, a “KEF Calinda” clone. They are now sitting on a shelf collecting dust, and I will most likely not use them again. I just have not found the time to sell them. Any idea how much they are still worth?

 

[planet10]

I can only relate experience i've had on eBay...

A set of Calinda i scored had broken tweeters... woofers went for $120/pr, passives for $40. Other T27s i've sold have gone from $40-80. Can't recall what the XOs fetched. I made a new baffle to replace the grills put an 8" with a whizzer into the box and gave them to my godson (2 yo)... it has been a LONG time snce i heard Calindas, but i suspect the retreads are more musically satisfying.

dave

 

[MRupp]

Thanks for your feedback. Considering that I almost left the drivers behind when I moved house that kind of price is not bad at all.

The XO was an 18dB "Butterworth" design with additional "phase correction" and was taken from a German loodspeaker book (Klinger, Lautsprecher und Lautsprechergehäuse für HiFi), so I am not sure how close it was to the original. I would be intriugued to rebuild the XO with better parts but I guess I will not have the time, especially since I do not have my original cabinets anymore and would have to build new cabinets as well.