Kef C80

BobA · 10th March 2004, 10:41 AM

I have a pair of KEF C80s that I purchased new in the 1980's. After almost 20 happy years, they're starting to show their age. The drivers are a T33 tweeter (SP1210, 4 ohm), B160 midrange (SP1203) and B139 woofer (SP1212). I suspect the both T33s (and possibly one B160) need replacement. Fortunately, both woofers are fine. I have been unable to replace any drivers directly from KEF America ("T33s may become available again sometime in July, we can't help you with the B160"). Can anyone help me obtain T/S parameters for the two drivers so I can begin searching for appropriate replacements?

Thanks.

Geoff · 10th March 2004, 11:49 AM

I have a KEF datasheet for the T33B (SP1210). Email me and I will send you a scan of it.

BobA · 12th March 2004, 03:35 PM

I received your email Geoff. It's exactly what I was looking for. Thank you.

BobA · 12th March 2004, 03:57 PM

I have another question along the same lines (sorry, I'm kind of new at this). I don't see much in the way of 4 ohm tweeters that will fit my C80s without requiring some cabinet modifications (which scares me). How much trouble would I create for myself by using an 8 ohm tweeter instead? Would KEF's "unique" conjugate load crossover complicate things?

sreten · 15th March 2004, 01:19 PM

An 8 ohm tweeter will not work well with the c/o.
Adding a 8R resistor in parallel is an option.

Also note the C10 uses the B160 driver apparently,
so a second-hand pair of these may be an option.
The tweeter may also suit, but I think its a different
shape and not as good as the T33.

sreten.

BobA · 15th March 2004, 04:01 PM

Good idea.

An 8 ohm resistor in parallel should work if we are basing its selection on the nominal impedances of the T33B and the replacement. Would it be more appropriate to use minimum impedance or DC resistance (or even something else)? Or am I being overly precise since they all should generate similar results?

sreten · 16th March 2004, 09:56 AM

Without the c/o schematic I couldn't say.

Especially if there are padding resistors involved.

sreten.

BobA · 16th March 2004, 11:30 AM

I don't know how I could find a crossover schematic.

It looks as if I should just play it safe and find myself a good quality 4 ohm tweeter. I guess I could wait until July and get new T33s from KEF (assuming that they really will have some available by then), but I never was very impressed with them. Even when the speakers were new, I thought that the tweeters weren't as good as the rest of the system.

Thank you for the advice.

planet10 · 16th March 2004, 07:25 PM

Quote:

Originally posted by BobA
KEF America

Try contacting KEF directly in England...

dave

BobA · 17th March 2004, 12:27 AM

I emailed KEF Audio (UK) and requested technical information on the drivers and crossover. I'll let you know what kind of response I get.

10th March 2004, 10:41 AM	#1
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	Kef C80 I have a pair of KEF C80s that I purchased new in the 1980's. After almost 20 happy years, they're starting to show their age. The drivers are a T33 tweeter (SP1210, 4 ohm), B160 midrange (SP1203) and B139 woofer (SP1212). I suspect the both T33s (and possibly one B160) need replacement. Fortunately, both woofers are fine. I have been unable to replace any drivers directly from KEF America ("T33s may become available again sometime in July, we can't help you with the B160"). Can anyone help me obtain T/S parameters for the two drivers so I can begin searching for appropriate replacements? Thanks. __________________ Bob

12th March 2004, 03:35 PM	#3
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	T33B I received your email Geoff. It's exactly what I was looking for. Thank you. __________________ Bob

12th March 2004, 03:57 PM	#4
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	4 ohms I have another question along the same lines (sorry, I'm kind of new at this). I don't see much in the way of 4 ohm tweeters that will fit my C80s without requiring some cabinet modifications (which scares me). How much trouble would I create for myself by using an 8 ohm tweeter instead? Would KEF's "unique" conjugate load crossover complicate things? __________________ Bob

15th March 2004, 04:01 PM	#6
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	Good idea. An 8 ohm resistor in parallel should work if we are basing its selection on the nominal impedances of the T33B and the replacement. Would it be more appropriate to use minimum impedance or DC resistance (or even something else)? Or am I being overly precise since they all should generate similar results? __________________ Bob

16th March 2004, 11:30 AM	#8
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	I don't know how I could find a crossover schematic. It looks as if I should just play it safe and find myself a good quality 4 ohm tweeter. I guess I could wait until July and get new T33s from KEF (assuming that they really will have some available by then), but I never was very impressed with them. Even when the speakers were new, I thought that the tweeters weren't as good as the rest of the system. Thank you for the advice. __________________ Bob


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10th March 2004, 11:49 AM	#2
Geoff diyAudio Member Join Date: Apr 2001 Location: UK	I have a KEF datasheet for the T33B (SP1210). Email me and I will send you a scan of it.

15th March 2004, 01:19 PM	#5
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	An 8 ohm tweeter will not work well with the c/o. Adding a 8R resistor in parallel is an option. Also note the C10 uses the B160 driver apparently, so a second-hand pair of these may be an option. The tweeter may also suit, but I think its a different shape and not as good as the T33. sreten.

16th March 2004, 09:56 AM	#7
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	Without the c/o schematic I couldn't say. Especially if there are padding resistors involved. sreten.

17th March 2004, 12:27 AM	#10
BobA diyAudio Member Join Date: Mar 2004 Location: New Jersey	I emailed KEF Audio (UK) and requested technical information on the drivers and crossover. I'll let you know what kind of response I get. __________________ Bob

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