Symptom Diagnosis please?

[panos29]

After a short play with my fynction generator in one of my two 15" Tannoy monitor I found that while in 100Hz raising the volume beyond a sertain point the sound comes a bit distorted, like a higher frequency is introduced together with the 100Hz(compared to the other. Any hints of what that may be? Maybe a loose turn on the voice coil? Any loudspeaker expert in here lease help! I am really desperate!

Sincerely,

Panos

 

[JOE DIRT®]

check both Drivers after the crossover and compare thats a good start

Cheers!!The DIRT®

 

[panos29]

My mistake! Forgot to mention that the test was done free air (on my bad) without the use of any kind of crossover. The differense is very obvious during the test between the two drivers.

 

[JOE DIRT®]

did you measure both voice coil resistances with a meter?

 

[panos29]

I did, both measure 6.5 Ohms and there absolutely no scratch when pushing in or pulling out the cones.

 

[JOE DIRT®]

well I must admit you have me stumped.....why did you test the speakers...was there a problem when listening to music?? any input from members here would be appreciated


Cheers!!The DIRT®

 

[panos29]

Actually I noticed during loud passages of electric guitar and specifically at the beginning of brothers in arms frrom dire straits that the small solo was a bit distorted so I switched to mono and listen the same just changing speakers. The feeling is like tha amplifier distorts somewhat more than usuall. But its now definitely the speaker that looses control at 100Hz as tested afterwards.

 

[JOE DIRT®]

I`m afraid my friend that the driver might in need of repair from what you have told me...I`m sorry i cant help you further....maybe someone else has another idea

Cheers!!The DIRT®

 

[panos29]

Dear Joe,
I really thank you for taking the time to answer to my question, I am afraid this is the case and although this is a very easy driver to take apart its extremely costly and hard to find spare parts. Damn, use to love that driver.

Thanks again

 

[JOE DIRT®]

maybe someone here could help you out getting parts at a decent price>???

 

[till]

Is there any part loose, a screw, cable or so that could start to rattle at frequencys over 100 Hz because of resonance?

 

[panos29]

I really triplecheck everything, and all is normal, the ratlle is above 100Hz maybe 3 times more that. but I cannot locate the location where it is coming from as the sound pressure level is a bit high and confusing. The problem is evident only past a sertain power level at low and medium the driver work o.k (of course we are speaking for the low frequency driver).

 

[till]

Is it possible there are particles/dirt betweem voice coil and magnet? did you play 100Hz and sahke it / turn it so any mess coud come out?

Else i think you have to open it... But better wait a few days before you do so, maybe someone will post the right idea.