My SCAN SPEAK Tweeters don't work !!!!

[Web Wolf]

Hi everybody, I'd like to post my problem with my SCAN-SPEAK tweeters D2904.

In fact, more than one year ago I bought these tweeters but they had the membrane a bit defective so I asked to SCAN SPEAK to repar them. After 3 months they substituted them and I saw the SPL and I thought it was very good. But now, I measured impedance curve of both speakers and I saw that one speaker have a perfect impedance but the impedance of the other speaker is full of garbage !!!



I repeated the measurements but it was the same result !!!

Perhaps there was a problem during substitution of the membrane but the real problem is that I can't use warranty now

What could I do ? Should I disassemble the tweeter ? How could I do ?

(please excuse my english)


HELP MEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!

 

[Helmuth]

You could try to open the tweeter and try to line up to see if the voice coil is vibrating free.

May be there is some dirt between the voice coil and pole plate.

 

[Web Wolf]

I could try.

I thought: may the tweeter be damaged by measurements with MLS signal ? I think it could be strange because we are speaking about few seconds and two ore three measurements...

Is there a way to post a photo here ?

Where could I put my photos ?

Thanks

 

[Helmuth]

With a test signal of 1w the speaker can't damage but with to low frequencies I don't know.
And the x-max the tweeter makes I guess.

 

[Web Wolf]

Consider we are speaking about few seconds of MLS signal !

I didn't never use a condenser because it could change phase response or not ?

 

[AndrewT]

you've blown it, it is not warranty.

Protect your tweeters by always feeding through a series capacitor to block DC and attenuate low frequencies.

 

[Web Wolf]

Only with few seconds of MLS signal ???

The membrane are perfect !!

 

[AndrewT]

I have never taken a tweeter apart, but I suspect the Voice Coil looks like the wire is little bigger than hair.

 

[Web Wolf]

I've a lot of old tweeters that were measured and played in every conditions but the impedance of them all are always perfect.

This tweeter never played without a condenser, only during two or three measurements.
It seems a little strange to have damaged a tweeter in this way.

Here are a photo of the impedance measured

 

[Web Wolf]

And here is the image of the other tweeter

Now I've measured the same tweeter (the "damaged" one) with a very low level and the impedance became better, but with two resonance points.

 

[Web Wolf]

And here is the image of the "damaged" one with the very low level

As you can see, the image is much more better, but there are two new resonance peaks

 

[pedroskova]

I vote for debris...take it apart and have a look.

 

[SY]

Does this tweeter have ferrofluid damping? Perhaps it's been contaminated or, as others have suggested, you have a piece of schmutz in the gap. Also possible that something else inside the tweeter has come loose (hopefully, not a winding of the voice coil!).

 

[Web Wolf]

This could be done but (excluding debris) what could be the problem inside a tweeter ?

And, If I take apart the tweeter, how could I center it again ?

 

[Web Wolf]

Before sending them to SCAN-SPEAK to substitue membranes the impedance curve were perfect for themselves !

But the membrane were a bit scratched so I asked a warranty change of them. Now a TW seems Ok, but the other have this strange impedance.

 

[Web Wolf]

I know no ferrofluid is in it

 

[gedlee]

The tweeter is bad. Looks like a classic loose voice coil turn or something else loose - hence the multiple peaks. I doubt debre in the gap.

At any rate, always us a cap in line with a tweeter. Its effect can be easily seen and removed if desired. But a blown tweeter is virtually unrepairable.

 

[mertztan]

I have a pair of D2905 brand new in box old stock if you like to replace

hi, you may thinking if you want to change new pair of Scan Speak, I have a pair of D2905 Scan Speak, if you like to change I can sell you at very low price. Email me at mertztan@hotmail.com, I can send you photo also