Tweeter replacement for Kef 107

On 3/1/07 7:40 AM, in article ,
"Arny Krueger" > wrote:

>
> "John Stone" > wrote in message
> ...
>
>> They too are
>> gone, having been purchased by Tymphany, which is an American company
>> based
>> in Silicon Valley.
>
> Is that Ken Kantor's place?

Yes

>> 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?

SEAS

>
> 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.

They ( the professionals) will adapt, somehow, the new tweeters to the
speakers enclosure.

> And don't change one Tweeter change both, and modify the crossover to
> suit the spec's of the new tweeters.

I have no idea how to change the crossover. I will not touch that.

>
> 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.

I don't mind spending more for a more desirable performance.
>
> 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.

What attracts me from choosing Kef's tweeters as replacement is that
it would be more likely to succeed in this replacement. But I know
virtually nothing about their new tweeters.

It is obvious that I am a novice here, but please excuse me if I
insist: if the tweeter has the appropriate impedance and sensitivity,
and it has the proper frequency range suitable for the cut-point, why
would I need to modify the crossover network?

I like the Kef 107 very much, but I always felt that the tweeters
could have been somewhat different.
So I am looking forward to replace them. But I what to do this very
carefully. For that I appreciated your inputs.

On 1 Mar 2007 19:41:15 -0800, "fid" > wrote:

>It is obvious that I am a novice here, but please excuse me if I
>insist: if the tweeter has the appropriate impedance and sensitivity,
>and it has the proper frequency range suitable for the cut-point, why
>would I need to modify the crossover network?

Because each of those numbers represents a snapshot of a continuously
varying parameter. Impedance at a single frequency does not
characterise the impedance across the spectrum adequately for
crossover design. Similarly, senstivity varies with frequency and the
crossover is designed to account for it. Picking by those single
numbers is insufficient and barely more useful than picking by color.

I recommend you accept KEF's recommendation.

Kal

"Kalman Rubinson" > wrote in message
...
> On 1 Mar 2007 19:41:15 -0800, "fid" > wrote:
>
>>It is obvious that I am a novice here, but please excuse me if I
>>insist: if the tweeter has the appropriate impedance and sensitivity,
>>and it has the proper frequency range suitable for the cut-point, why
>>would I need to modify the crossover network?
>
> Because each of those numbers represents a snapshot of a continuously
> varying parameter. Impedance at a single frequency does not
> characterise the impedance across the spectrum adequately for
> crossover design.

Actually....the term impedance implies a complex
model that will vary response with frequency.

I think you're confusing nominal impedance.

If the complex impedance of the drivers are the same,
then the response of the crossover will not be adversely
affected. Then if the sensitivity of the drivers are the same,
the basic response will be very similar.
Only significant variable left is dispersion patterns and baffle
interaction.

I would agree that most driver specs don't make it easy to
determine the true impedance of the driver.

>Similarly, senstivity varies with frequency and the
> crossover is designed to account for it.

Freq. sensitivity plots are readily available though.
For example
http://www.madisound.com/pdf/seas/e006.pdf

> Picking by those single
> numbers is insufficient and barely more useful than picking by color.
>
> I recommend you accept KEF's recommendation.

How much is it?

ScottW

On Mar 3, 1:35 pm, "ScottW" > wrote:
> "Kalman Rubinson" > wrote in message
>
> ...
>
> > On 1 Mar 2007 19:41:15 -0800, "fid" > wrote:
>
> >>It is obvious that I am a novice here, but please excuse me if I
> >>insist: if the tweeter has the appropriate impedance and sensitivity,
> >>and it has the proper frequency range suitable for the cut-point, why
> >>would I need to modify the crossover network?
>
> > Because each of those numbers represents a snapshot of a continuously
> > varying parameter. Impedance at a single frequency does not
> > characterise the impedance across the spectrum adequately for
> > crossover design.
>
> Actually....the term impedance implies a complex
> model that will vary response with frequency.
>
> I think you're confusing nominal impedance.
>
> If the complex impedance of the drivers are the same,
> then the response of the crossover will not be adversely
> affected. Then if the sensitivity of the drivers are the same,
> the basic response will be very similar.
> Only significant variable left is dispersion patterns and baffle
> interaction.
>
> I would agree that most driver specs don't make it easy to
> determine the true impedance of the driver.
>
> >Similarly, senstivity varies with frequency and the
> > crossover is designed to account for it.
>
> Freq. sensitivity plots are readily available though.
> For examplehttp://www.madisound.com/pdf/seas/e006.pdf
>
> > Picking by those single
> > numbers is insufficient and barely more useful than picking by color.
>
> > I recommend you accept KEF's recommendation.
>
> How much is it?
>
> ScottW

> ScottW

Kef replacements are selling for $160.

If you tell me to stop thinking about those ScanSpeaks Revelators,
then I will definitely choose the Kef's. But if the ScanSpeak will
produce an acceptable sound without scratching noises.. why not, I
would think!

"fid" > wrote in message
ups.com...
> On Mar 3, 1:35 pm, "ScottW" > wrote:
>> "Kalman Rubinson" > wrote in message
>>
>> ...
>>
>> > On 1 Mar 2007 19:41:15 -0800, "fid" > wrote:
>>
>> >>It is obvious that I am a novice here, but please excuse me if I
>> >>insist: if the tweeter has the appropriate impedance and sensitivity,
>> >>and it has the proper frequency range suitable for the cut-point, why
>> >>would I need to modify the crossover network?
>>
>> > Because each of those numbers represents a snapshot of a continuously
>> > varying parameter. Impedance at a single frequency does not
>> > characterise the impedance across the spectrum adequately for
>> > crossover design.
>>
>> Actually....the term impedance implies a complex
>> model that will vary response with frequency.
>>
>> I think you're confusing nominal impedance.
>>
>> If the complex impedance of the drivers are the same,
>> then the response of the crossover will not be adversely
>> affected. Then if the sensitivity of the drivers are the same,
>> the basic response will be very similar.
>> Only significant variable left is dispersion patterns and baffle
>> interaction.
>>
>> I would agree that most driver specs don't make it easy to
>> determine the true impedance of the driver.
>>
>> >Similarly, senstivity varies with frequency and the
>> > crossover is designed to account for it.
>>
>> Freq. sensitivity plots are readily available though.
>> For examplehttp://www.madisound.com/pdf/seas/e006.pdf
>>
>> > Picking by those single
>> > numbers is insufficient and barely more useful than picking by color.
>>
>> > I recommend you accept KEF's recommendation.
>>
>> How much is it?
>>
>> ScottW
>
>> ScottW
>
> Kef replacements are selling for $160.

Is that each or a pair?

>
> If you tell me to stop thinking about those ScanSpeaks Revelators,
> then I will definitely choose the Kef's. But if the ScanSpeak will
> produce an acceptable sound without scratching noises.. why not, I
> would think!

I think substituting drivers is just an absolute crapshoot
as the information you would need to identify a
well matched replacement isn't available.

However, the was a report from a guy that says the
Vifa MG27 is an easy fit and sounded good.
Thats a $44 crapshoot...and Madisound might be willing
to offer a return if you don't solder leads for a nominal restocking
fee. Point is...there is a risk vs reward decision and only you
can evaluate how much risk you're willing to assume.

ScottW

On Sat, 3 Mar 2007 10:35:14 -0800, "ScottW" >
wrote:

>Actually....the term impedance implies a complex
>model that will vary response with frequency.
>
>I think you're confusing nominal impedance.

Not confusing the terms but, unfortunately, I didn't use the correct
ones explicitely. As you state, the nominal impedance is almost
always offered but the complex impedance graph less commonly.

I am in agreement with you that swapping drivers is a crap-shoot
unless one is willing and able to undertake a potential redesign.

Kal

"Kalman Rubinson" > wrote in message
...
> On Sat, 3 Mar 2007 10:35:14 -0800, "ScottW" >
> wrote:
>
>>Actually....the term impedance implies a complex
>>model that will vary response with frequency.
>>
>>I think you're confusing nominal impedance.
>
> Not confusing the terms but, unfortunately, I didn't use the correct
> ones explicitely.

**You explained it perfectly. Scotty is an idiot.


--
Trevor Wilson
www.rageaudio.com.au



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

"fid" > wrote in message
ups.com...
> On Mar 3, 1:35 pm, "ScottW" > wrote:
>> "Kalman Rubinson" > wrote in message
>>
>> ...
>>
>> > On 1 Mar 2007 19:41:15 -0800, "fid" > wrote:
>>
>> >>It is obvious that I am a novice here, but please excuse me if I
>> >>insist: if the tweeter has the appropriate impedance and sensitivity,
>> >>and it has the proper frequency range suitable for the cut-point, why
>> >>would I need to modify the crossover network?
>>
>> > Because each of those numbers represents a snapshot of a continuously
>> > varying parameter. Impedance at a single frequency does not
>> > characterise the impedance across the spectrum adequately for
>> > crossover design.
>>
>> Actually....the term impedance implies a complex
>> model that will vary response with frequency.
>>
>> I think you're confusing nominal impedance.
>>
>> If the complex impedance of the drivers are the same,
>> then the response of the crossover will not be adversely
>> affected. Then if the sensitivity of the drivers are the same,
>> the basic response will be very similar.
>> Only significant variable left is dispersion patterns and baffle
>> interaction.
>>
>> I would agree that most driver specs don't make it easy to
>> determine the true impedance of the driver.
>>
>> >Similarly, senstivity varies with frequency and the
>> > crossover is designed to account for it.
>>
>> Freq. sensitivity plots are readily available though.
>> For examplehttp://www.madisound.com/pdf/seas/e006.pdf
>>
>> > Picking by those single
>> > numbers is insufficient and barely more useful than picking by color.
>>
>> > I recommend you accept KEF's recommendation.
>>
>> How much is it?
>>
>> ScottW
>
>> ScottW
>
> Kef replacements are selling for $160.
>
> If you tell me to stop thinking about those ScanSpeaks Revelators,
> then I will definitely choose the Kef's. But if the ScanSpeak will
> produce an acceptable sound without scratching noises.. why not, I
> would think!

**Have you read ANY of the posts from those who actually know? Or are you
being deliberately obtuse?


--
Trevor Wilson
www.rageaudio.com.au



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

"Kalman Rubinson" > wrote in message
...
> On Sat, 3 Mar 2007 10:35:14 -0800, "ScottW" >
> wrote:
>
>>Actually....the term impedance implies a complex
>>model that will vary response with frequency.
>>
>>I think you're confusing nominal impedance.
>
> Not confusing the terms but, unfortunately, I didn't use the correct
> ones explicitely. As you state, the nominal impedance is almost
> always offered but the complex impedance graph less commonly.
>
> I am in agreement with you that swapping drivers is a crap-shoot
> unless one is willing and able to undertake a potential redesign.
>
> Kal


It comes down to how much work your prepaired for, if you just want
the same result, by all means go for the KEF replacements, They
should be the same values as the one's there replacing, and should not
require any work on the crossovers. Plus, they will fit.

If you deside on the Vifa's Scan Speak, or whatever, for best results
you will need to play with the "cap' values
in the crossover, to obtain a balanced result,
As our friend states above, it's a "crap-shoot" you can buy the worlds
best, but get the crossover values wrong, and they will sound like crap,
and the cheapest tweeters around with good matching crossover componants
will sound like the "ducks nuts" It's all about trial and error


bassett