Bextrene as a driver material ?

[john & Jake the dog]

Hi,
I've put my Isobariks away for the time being as my system changes to accomodate the Kel84.
Listening to Castle Clydes in the unchanged system and can't believe the difference.
With the volume lowish there is a lot of detail and they sound pretty accurate, sax sounds, cymbal sounds and accoustic guitar all believable.
Turn the volume up a bit and upper bass is there to follow the ups and downs of the bass.

Now I've been an Isobarik fan since the 80's and on my second pair now but the Clydes have shown up something lacking in the B110 and possibly the Scanspeak tweeter.
Listening tonight I was thinking just what would the Isobarik sound like with the Clyde's drivers.
I think Bass/mid are paper, not sure about the tweeters, but this raises the question, is Bextrene a suitable material for drivers?

cheers
john

[Phil Y]

I think it is just a case of time and technology marches on. Bextrene was good when KEF and others started using it in the early 1970s but that was a long time ago. Some old meterials can still be made to work well like paper, but no one(i believe) has used bextrene for years. As for the Scanspeak tweeters, i recently replaced these in my own speakers(same type i think) with some Morel MDT33s to great effect.

Cheers, Phil

[andrew ivimey]

But are you comparing like with like... you have put your isobariks away.

change one variable at a time and then you might be able to judge. But bear in mind that any change produces a change which isn't necesarily better, just different. Better takes time to discern.

With your previous question about LS3/5as, it was so speculative to be almost worthless.

One variable at a time and then it is what suits you.

[john & Jake the dog]

hi,
QUOTE
But are you comparing like with like... you have put your isobariks away.

change one variable at a time and then you might be able to judge.


I'll clarify.
I have put my Isobariks away before my Kel84 kit arrives.

I said I was listening to my Clydes on an unchanged system IE Marantz cd 6000ose, Meridian 101, Exposure IV, then the one variable, the Clydes.

I have been auditioning equipment since the 80's and know the value of changing just one part of a system at a time, the next one variable to change will be the amplification when my Kel84 is finished. By then I will know what the Clydes sound like.

QUOTE
With your previous question about LS3/5as, it was so speculative to be almost worthless.


I needed to know the viability of using LS35a's with valve amps because it is a speaker I have thought of owning but with a change to Valves I didn't know whether Valves could drive them.
Members have answered that for me and now I will not contemplate spending good money on a speaker that will not suit my purpose.

Cheers
john

[petercom]

Bextrene, like many 'soft' plastics such as polypropylene, was used because it was very easy to mould into different shapes and therefore experiment with, as well as having fairly good self damping. It ideally needed to be treated with a surface damping material, usually Plastiflex, otherwise it tended to 'quack' in the midrange due to forced midrange resonance. The forward midrange that remained was fairly easy to treat in the crossover.

Although I used Bextrene in the Heybrook HB2, largely because of its unusual combination of fairly high mass and good midrange sensitivity, I have always preferred working with good paper cones since.

[john & Jake the dog]

Hi Peter,
Thanks for the technical stuff, not very good at that, but I know what I like when I hear it.

Would the Kel84 be happy with a 4ohm speaker?

On a completely different note, would we have met at a Hi Fi show in Harrogate in the 80's in a hotel when I was very kindly bought lunch by the Heybrook representative. I was with Richard Ashman of Gilson Audio of Middlesbrough.
Richard gave me my first listen to Heybrook speakers at his home over the road from me at the time.

[petercom]

KEL84 will drive a 4 Ohm speaker but not develop its full output into it as it has an 8 Ohm tap on its output. Mind you that depends on how '4 Ohm' the speaker really is. It may only be 4 Ohms at one frequency and 6-8 Ohms over the majority of the frequency range, in which case it will be a good match to KEL84.

On the meeting front I would certainly have met you if you had been with Richard. Wouldn't have recognised you without Jake, though!

[john & Jake the dog]

Hi Peter,
Thanks for the info, I was thinking of B & W 620i's.
I didn't have Jake back then but I had two Old English sheepdogs.
Enjoyed the shows very much, got to meet yourself and listen to some great gear, not managed to get to a show since.

cheers