Tweeter replacement for Kef 107

"AZ Nomad" > wrote in message
...
> On Wed, 28 Feb 2007 10:28:37 +1100, Trevor Wilson
> > wrote:
>
>
>
>>"fid" > wrote in message
groups.com...
>>On Feb 19, 9:45 pm, François Yves Le Gal > wrote:
>>> On 19 Feb 2007 17:03:29 -0800, "fid" > wrote:
>>>
>>> >The problem is that after so many
>>> >years of daily usage I am afraid the they are wearing off.
>>>
>>> Properly usedtweetersdon't really wear. OTOH the T33's use Ferrofluid,
>>> which sometimes can harden and become problematic .
>
>>I don't know much about speaker's subcomponents and replacements.
>
>>**Then forget about replacing tweeters. Just use the OEM parts. You cannot
>>substitute *any* drivers in a system, without intimate knowledge of the
>>characteristics of the replacements, the crossover values and you need to
>>know EXACTLY what you are doing. However, you'll likely ignore this,
>>because
>>you've been told this before.
>
> Tweeters typically are sealed and not tuned w/ the cabinet.

**Correct. That is 10% of the story. There are more important issues to be
concerned with. Impedance levels dictate crossover points. The 107 has Zobel
networks on each driver, which are intimately associated with the impedance
characteristics of the driver. Hoping to find a replacement tweeter with an
identical impedance curve is bordering on impossible. That said, someone
with plenty of experience and some decent test equipment COULD do the job.
However, anyone who has to ask questions here, clearly is well out of their
depth. As is anyone who makes nonsensical, glib statements like yours.

As long as the
> frequency response of the replacement tweeter is adequate, the main
> problem is
> matching levels.

**Wrong. That is another 10% of the problem.

Get a replacement tweeter that has the same sensativity and
> the replacement will work.

**Work? Certainly. Work well? Not likely. You're talking out of your arse.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

On Feb 19, 4:13 pm, "fid" > wrote:
> Hello,
> Can you please suggest hi-quality tweeters to replace the T33s for the
> kef 107s? I was thinking at the Scan-Speak D2905/9500. Could the
> faceplate of these tweeters be swapped to fit different speakers? I
> appreciate any inputs.
> Thank you

Heres a thread on replacing T33s in KEF104s.

http://audiokarma.org/forums/showthr...t=76529&page=2

One guy used a VIFA MG27 available from Madisound for ~$22 and claims
good results.
Worth a shot at that price.

ScottW

"fid" > wrote in message
oups.com...
> Hello,
> Can you please suggest hi-quality tweeters to replace the T33s for the
> kef 107s? I was thinking at the Scan-Speak D2905/9500. Could the
> faceplate of these tweeters be swapped to fit different speakers? I
> appreciate any inputs.

Check this tech info about what tweeters were used in various products.
Perhaps you can find one of them for a reasonable price:

http://www.hifiloudspeakers.info/Ana...erSystems.html

On Feb 19, 4:13 pm, "fid" > wrote:
> Hello,
> Can you please suggest hi-quality tweeters to replace the T33s for the
> kef 107s? I was thinking at the Scan-Speak D2905/9500. Could the
> faceplate of these tweeters be swapped to fit different speakers? I
> appreciate any inputs.
> Thank you

Unless you are prepared to re-enineer your speakers, it is best to use
the same model, since the speaker system's xover was designed for the
T33, nothing else will work exactly the same. Things like the rolloff
of he tweeter and how it meshs with the driver handling the lower
frequency range will almost surely be different.

Xover design is like most things in speaker design, a compromise,
there is no drop in replacement other than the driver that the system
came with.

Unless you are willing to invest in the equipment neccessary to model
and measure the results of any driver changes, then it is best to
leave things as they were originally designed.

"François Yves Le Gal" > wrote in message
...
> On Wed, 28 Feb 2007 11:36:39 -0500, "Arny Krueger" >
> wrote:
>
>>I can't believe that KEF doesn't have a replacement tweeter for sale at
>>price that is vastly less costly than the used equipment value of the
>>speaker.
>
> Kef has become another empty shell with basically badge-engineered Chinese
> products.
>
So it seems. I did some research on the subject and came up with my other
post about possible ways to obtain T33s.

"fid" > wrote in message
oups.com...
> On Feb 21, 4:37 am, "bassett" > wrote:
>> "fid" > wrote in message
>>
>> >I don't know much about speaker's subcomponents and replacements. I
>> >spoke to a costumer service at Madisound about the possibility of
>> >replacing thetweeters. When I asked him about scanspeak he wasn't
>> >favorable about them. He said: "The D2905/9500 is a classic highend
>> >tweeter. All 1" Scan-Speaktweetershave a metal face plate...so it
>> >would be difficult to modify". Can anyone explain this? Don't all the
>> >tweeterscome with a removable faceplate (kef 107 uses square
>> >faceplate)? Thanks
>>
>>
>> If your looking for replacements consider the new Scan Speak
>> D2905-990000 Revelator, this is particularly good as a replacement as
>> it
>> has a 130 mm faceplate, and will cover up most if not all old fitting
>> holes
>> There priced at two fifty dollars
>>
>> If you wantHi-end the Scan speak super tweeter [2k- 80khz] R2904-700000.
>> prices range between four and five hundred depending on where you get
>> them.
>> Face plate size is again 104mm
>>
>> Then we have the Twin Ribbon 100khz super tweeter from Jas Audio at
>> $1500
>> each.
>> and very nice they are too.
>>
>> bassett
>
> Thank you for posting your input. You are suggesting Scan Speak
> D2905-990000. But does it have a removable faceplate? Please note
> that my kefs have an unusual square plate.
> However, why would I get a tweeter that goes as hi as 100Hz when the
> human hearing is virtually def in those frequencies?
>
> Thanks
> Fid
>

You will find that very few if any Tweeters have a removable face
plate, what you will need to do is fabrecate an adapter plate to go
between the speaker cabinet and the inside of the round Tweeter face
plate.
And don't change one Tweeter change both, and modify the crossover to
suit the spec's of the new tweeters.
It really is not as simple as removeing 4 screws, and replaceing the
unit.. Well it is , if you have no idea about how they should perform.
As to the Vifa 25 dollar specials, Sure they will work, It's a bit
like sticking a VW donk in a Murcialago, [Or as TW said about the fual
injection] we know it will work, but performance is another thing
entirly .

As to the question about 100Hz rated tweeters, [ the scan speak 700000
are rated at 80 Hz ] you really have to hear the things to
understand. Again, if you want good performance, you will have to pay
for it.

Will Kef supply a PAIR of new tweeters, to suit there cabinets, and
strange as it might seem, have you tested them, disconnected from the
crossover, your speaker fault could well be a crossover componant,, It
does happen,, but i don't have any idea about the crossovers in the Kef,
it could be a complex unit, or simply just a "cap'' in the line.

bassett

On Feb 28, 11:36 am, "Arny Krueger" > wrote:
> "François Yves Le Gal" > wrote in
> messagenews:[email protected] .com
>
> > On Wed, 28 Feb 2007 15:54:18 GMT, AZ Nomad
> > > wrote:
>
> >> Tweeters typically are sealed and not tuned w/ the
> >> cabinet.
> > Baffle diffraction anyone?
>
> Crossovers, anyone?
>
> >> As long as the
> >> frequency response of the replacement tweeter is
> >> adequate, the main problem is matching levels. Get a
> >> replacement tweeter that has the same sensativity and
> >> the replacement will work.
> > Nope. Tweeters can display superficially identical
> > sensitivities and responses while having very different
> > electrical and/or acoustical properties.
>
> Agreed. This is a KEF 107, not a FungooTek computer speaker. It is
> definately worth it to do it *right*.
>
> I can't believe that KEF doesn't have a replacement tweeter for sale at
> price that is vastly less costly than the used equipment value of the
> speaker.

I did contact Kef (UK & USA). Apparently they will soon have available
some replacement tweeters. I had to beg them to give me some info.
Finally the rep at Kef USA told me that it is a soft dome and the part
number is R1549X. That's only I know. No name of maker or where it is
conceived.

However. I contacted some professionals and they would at least
attempt to install a pair of ScanSpeak (even that he was more
comfortable to suggest a SEAS). No change to be made at the crossover,
thou.
When i told him that I was looking for a tweeter with the impedance of
4ohms he replied like this: "Your system is rated at 4 ohm, not the
tweeter. Systems a rated for the woofer impedance since they draw 80%
of the power from the amp. If you have access to an ohm meter, you can
check the good tweeter your self. An 8 ohm tweeter will usually have a
dc resistance of between 6-7 ohms.
A 4 ohm units would have a dcr of 3-4 ohm."

Why change tweeters? The left tweeter has less (or darker) output then
the right tweeter. It's a sign...

Best,
Fid

"fid" > wrote in message
ps.com...

On Feb 28, 11:36 am, "Arny Krueger" > wrote:

>> I can't believe that KEF doesn't have a replacement tweeter for sale at
>> price that is vastly less costly than the used equipment value of the
>> speaker.

>I did contact Kef (UK & USA). Apparently they will soon have available
>some replacement tweeters. I had to beg them to give me some info.
>Finally the rep at Kef USA told me that it is a soft dome and the part
>number is R1549X. That's only I know. No name of maker or where it is
>conceived.

I get the impression that the origional T-33 was a Vifa-made unit. Vifa is
now a brand of DAP, whose other brands are SEAS and ScanSpeak

>However. I contacted some professionals and they would at least
>attempt to install a pair of ScanSpeak (even that he was more
>comfortable to suggest a SEAS). No change to be made at the crossover,
>thou.

This would be an experiment. What's the down side, costs?


> When i told him that I was looking for a tweeter with the impedance of
> 4ohms he replied like this: "Your system is rated at 4 ohm, not the
> tweeter. Systems a rated for the woofer impedance since they draw 80%
> of the power from the amp. If you have access to an ohm meter, you can
> check the good tweeter your self. An 8 ohm tweeter will usually have a
> dc resistance of between 6-7 ohms.

All true statements, but not really responsive to your question. In the US
we speak of "Snow Jobs".


>A 4 ohm units would have a dcr of 3-4 ohm."

Also true, but relating how to the price of tea at the supermarket?

>Why change tweeters? The left tweeter has less (or darker) output then
> the right tweeter. It's a sign...

Presumably you've physically exchanged the speakers in your listening (left
& right swap) and the problem stayed with the speaker.

On 3/1/07 6:36 AM, in article ,
"Arny Krueger" > wrote:

> I get the impression that the origional T-33 was a Vifa-made unit. Vifa is
> now a brand of DAP, whose other brands are SEAS and ScanSpeak

KEF never had drive units made by Vifa. The T-33 was made by KEF in Britain.
Vifa is gone. The brand has been rolled into Peerless, and the old Vifa
products, few of which are still available, are sold under the "Peerless
V-line" I don't have any idea what DAP is, but the umbrella company that
previously owned Vifa, ScanSpeak, and Peerless was called DST. They too are
gone, having been purchased by Tymphany, which is an American company based
in Silicon Valley. The same venture company that holds Tymphany also owns
Klipsch and Jamo. SEAS has always been completely independent of the others
and remains so today. It is employee owned.

"John Stone" > wrote in message
...
>
> On 3/1/07 6:36 AM, in article
> ,
> "Arny Krueger" > wrote:
>
>> I get the impression that the origional T-33 was a Vifa-made unit. Vifa
>> is
>> now a brand of DAP, whose other brands are SEAS and ScanSpeak

> KEF never had drive units made by Vifa.

So much for the web page that suggested it to me. Hmm which of the many I
looked at yesterday was that?

> The T-33 was made by KEF in Britain.

> Vifa is gone. The brand has been rolled into Peerless, and the old Vifa
> products, few of which are still available, are sold under the "Peerless
> V-line" I don't have any idea what DAP is, but the umbrella company that
> previously owned Vifa, ScanSpeak, and Peerless was called DST.

DAP was corruption of DST, you know Danish-something. In this case my
coffee-starved memory coughed out "Danish Audio Products", but that's wrong.

> They too are
> gone, having been purchased by Tymphany, which is an American company
> based
> in Silicon Valley.

Is that Ken Kantor's place?

> The same venture company that holds Tymphany also owns
> Klipsch and Jamo. SEAS has always been completely independent of the
> others
> and remains so today. It is employee owned.

Thanks for the correction, John. If anybody would know this stuff, it would
be you. Are you doing any work for any of the above?