T27

[john & Jake the dog]

Hi
would the seas h107 be a decent replacement for the kef t27?

[Phil Y]

Hi John,
That really is a virtually impossible question to answer ! If you were going to stick them in a pair of LS35As then the answer is an emphatic NO. If on the other hand you are building a pair of speakers from scratch then possibly yes. Personally, I don't like T27s much, they are a very old dome tweeter and sound it. I don't know your Seas units, but Seas are a good brand and if they are a younger design there is a good chance they could sound better in a suitable design with the correct crossover.
What were you planning on doing with them ?

Regards, Phil.

[john & Jake the dog]

hi phil,
I have obtained a pair of kef104 cabinets in good nick.
I have 2 b200s(may not be the correct sp, but it may not matter) and 2 b139 abrs.
I have the correct crossovers and controls. I'll recap with wilmslow audio's upgrade.
I was going to put them together to see how they sound.
I planned this before I bought my heybrooks, which I'm delighted with, so if they sound alright I'll sell them on.

[Phil Y]

If I understand you the xovers are for an all KEF lineup?
If so, I would not think the Seas units will be very well matched. The T27s were always used with values a long way from the theoretical as this was what was needed to get a reasonable response from them. No harm in giving it a go though, you might just get lucky.

It has just come back to me, when I was a teenager and messing around with speakers, I had a pair of Kef 3 way xovers. I was using Scanspeak tweeters and they sounded pretty bad despite the Scanspeaks being a favourite at the time. In the end I got a book out of the library and recalculated the tweeter section with simple theoretical values. It sounded miles better than with the values for the T27. I am sure it was still far from ideal though!

Although I have given up on "messing around" with speakers(it was designing xovers that defeated me) and now use a commercially made pair, I learnt a lot and don't regret a moment of it.

Phil

[john & Jake the dog]

hi phil,
here's the specs for the seas unit
http://www.seas.no/images/stories/vi..._dome_h107.pdf

the sensitivity is quoted ar 91 whereas here
http://homepages.tcp.co.uk/~nroberts/article85b.pdf
the kef is quoted at 80, so a bit of experimentation with resistors may produce something, possibly

[Phil Y]

You will need an L-pad to drop the tweeter to a suitable level and keep the impedance at about 8 ohm. A single series resistor large enough in this case will probably upset things. I think that will be the least of your worries though, I would expect the L and C values to be wrong for the Seas unit, but as I said above you have nothing to loose by giving it a go.

Phil.

[john & Jake the dog]

hi Phil, In the absence of cheapish t27's I am dropping the seas units into a pair of 104 reference.
these have a control, is that the sort of thing you mean?

If I can't get intelligible sound from them I'll be posting a want for T27's but I will have to keep the costs down or it will be uneconomic

[Phil Y]

Yes, a level control (presumably a wire wound pot) would be just the job but I would imagine they will set up to give a small range of trim with the T27. They may not have enough adjustment to bring the Seas down to the right level.
There is only one way to find out.

Phil.

[john & Jake the dog]

cheers phil.
I'll have fun finding out I'm sure.
I'll be tinkering with the 104s in between starting from scratch (again)modding my latest Marantz cd6000
I just hope I've learnt not to lift tracks