Good morning to Everyone
Being interested in vintage loudspeakers I understand that TS parameters of a driver can vary with its age
I wonder why and what type of drivers can be more critical in this regard
Any suggestion and advice would be very welcome and precious
Thank you very much indeed
Being interested in vintage loudspeakers I understand that TS parameters of a driver can vary with its age
I wonder why and what type of drivers can be more critical in this regard
Any suggestion and advice would be very welcome and precious
Thank you very much indeed
I think the biggest thing that changes with age is the surround/suspension of the driver. IME foam surround is the worst, especially if it's exposed to UV or a lot of temperature cycles. Accordion paper and rubber surrounds are supposed to be better in this respect. This aging will change the resonant frequency(Fr), Vas and Q factors.
TS parameters can be measured if one has a few basic bench instruments. So one could tell how far out the drivers have gone if they're willing to put in the effort and they know what the original alignment was supposed to be.
TS parameters can be measured if one has a few basic bench instruments. So one could tell how far out the drivers have gone if they're willing to put in the effort and they know what the original alignment was supposed to be.
Hi thank you for the very kind and valuable advice
I have two old ITT 2" dome midranges
FS 980Hz and 1.2kHz and with different impedance curves as well
I have a Dats v3 to measure drivers
In origin I guess it should have been lower and similar
It would be nice if new compatible domes were available like it happens with compression drivers or woofer cones
This stopped my hunt for vintage drivers unfortunately
I think that vintage cone drivers could be a safer bet
No more old domes
I have two old ITT 2" dome midranges
FS 980Hz and 1.2kHz and with different impedance curves as well
I have a Dats v3 to measure drivers
In origin I guess it should have been lower and similar
It would be nice if new compatible domes were available like it happens with compression drivers or woofer cones
This stopped my hunt for vintage drivers unfortunately
I think that vintage cone drivers could be a safer bet
No more old domes
Thanks. Good information. Didn't think they'd drift that far out from each other. Or, if they did drift, they'd both go in the same direction.
Now I think your best bet is to try to find something new that gets as close to where you want to be as possible.
Personally, I would never buy something really old unless it was in the box and had never been part of a speaker. And even then, if it was stored in a garage or something like that with humidity and temperature cycles,, it could significantly age the drivers.
I've read the flux density of the magnets can also change over time with hard use or if they've been exposed to any shock. This is one of the problems with permanent magnets. They're not guaranteed to hold their magnetization over time.
Now I think your best bet is to try to find something new that gets as close to where you want to be as possible.
Personally, I would never buy something really old unless it was in the box and had never been part of a speaker. And even then, if it was stored in a garage or something like that with humidity and temperature cycles,, it could significantly age the drivers.
I've read the flux density of the magnets can also change over time with hard use or if they've been exposed to any shock. This is one of the problems with permanent magnets. They're not guaranteed to hold their magnetization over time.
Old speakers need to be remeaured and the cabinet/crossover should be based on those measurements i think. I restored many old speakers, and very often you can make them work again in a good manner, but you need to adapt to the aging drivers. It's indeed mainly the surround and spider that change, but often also the cone (in lesser degree) that stiffens up, especially when the speaker was in storage for a while.
Old (dome) tweeters also can have dried out fluid, that can have a big impact. Replacing that fluid is a specialist job.
Old (dome) tweeters also can have dried out fluid, that can have a big impact. Replacing that fluid is a specialist job.
Good morning ! i was surprised too and very sad because these were presented by the poor guy ATC nothing to compare with the amazing drivers so popular in the recording studios these days
I think that fs has indeed drifted in the same direction i.e. increasing
I have never seen a 2" mid with fs=1kHz
I have another pair same part number to check in another old speaker
Yes but i am abandoning the idea of getting dome mids I have stil a pair of Dynaudio d-52af to try out
actually i have a bizarre idea Ask a friend to build two wood lenses to be put on top Like they did for the d52
the reference being always the wonderful ATC
they say that the lens has a lot to do with the actual performance I guess it could lower the distortion ?
imho it will be important that the two lenses will be identical
thank you very much for your precious advice I am setting up a portable system based on a tablet with a usb calibrated mic and a small portable amp to be able to perform some basic measurements on speakers on the go The idea is to buy only after some basic measurements
i have seen a video of which i cannot find the link anymore where they were testing an old Acoustic Research speakers pair
The two speakers showed a nicely similar frequency response after about 50 years If they aged they did it at the same way lets say
In another case there were differences but due to electrolytics in the xovers
You may ask why messing up my life like this I answer because there is more and more ignorance around
You can find old quality speakers at ridiculous prices Uneducated people find old speakers and do not understand the potential value
Moreover looking at the current catalogs I see prices for the drivers really high
A pair of woofers can easily cost 500-600 euros
I bought two speakers with another pair of the mids mentioned above (still to be measured) two excellent tweeters and two decent woofers for 50 euros that the owner was thinking of throwing in the garbage For example
Hi thank you very much for your kind and valuable advice
Aging is of course a real issue What i would like to understand which driver types can be more affected by aging
the idea is to set up a portable measuring system to check at least the frequency response and TS parameteres
if FR and TS parameters match nicely it will be a good sign i guess
Redoing the xover should not be a big issue I have been sincerely impressed by the power of some design SW Very impressed
maybe i am too optimistic but it could be that a revised xover provides better performance ? there are companier around that do just that
They redesign xover of commercial speakers to elevate their performance
Thanks again for the precious advice I think i have seen the datasheet of two identical tweeters one with fluid and another without
The performance changes very slightly
Anyway my goal will be to have parts that behave similarly Some tweeters can work also without fluid
But i have to try I dont see tweeters as a problem I am more concerned with woofers and cone mids