I'm looking into replacing the old Focal TC120K (kevlar) tweeters on my Impulse Lali (UK spkr company now defunct). The form surrounds have deteriorated badly.
The crossover has 3.3uF and 2.2R in series with a 15R across the tweeter. I would, of course, have to change the values to accomodate a different tweeter. But I hate to (and don't know how anyway) to start designing a higher order crossover.
Focal has stopped selling drivers, and I'd rather not use it's last released TD120 TD5 which has been sitting on the shelves for some time, and whose form surrounds may have started deteriorating in the box. In any case, the Lali's TC120Ks likely have been tweaked by Impulse (further damped) to work with the simple crossover, and there is no reason to believe the TC120 TD5 is a simple drop-in.
Any ideas? Thanks in advance!
The crossover has 3.3uF and 2.2R in series with a 15R across the tweeter. I would, of course, have to change the values to accomodate a different tweeter. But I hate to (and don't know how anyway) to start designing a higher order crossover.
Focal has stopped selling drivers, and I'd rather not use it's last released TD120 TD5 which has been sitting on the shelves for some time, and whose form surrounds may have started deteriorating in the box. In any case, the Lali's TC120Ks likely have been tweaked by Impulse (further damped) to work with the simple crossover, and there is no reason to believe the TC120 TD5 is a simple drop-in.
Any ideas? Thanks in advance!
Hi Alex S
You might want to check this tweeter that is featured in Hobby Hifi this month: http://www.volkslautsprecher.com/html/mh1.html It's a drop in replacement of the TC120 with lower FS because it has a rear chamber , a sanwich voice coil for lower distortion, etc etc and has exactly the same looks ( the pic in their web page is horrible, it looks much better in the magazine). Might just be the ticket if you don't want to rework the front of your impulses to adapt different units.
regards
Tom
You might want to check this tweeter that is featured in Hobby Hifi this month: http://www.volkslautsprecher.com/html/mh1.html It's a drop in replacement of the TC120 with lower FS because it has a rear chamber , a sanwich voice coil for lower distortion, etc etc and has exactly the same looks ( the pic in their web page is horrible, it looks much better in the magazine). Might just be the ticket if you don't want to rework the front of your impulses to adapt different units.
regards
Tom
Tom,
thank you for you reply. I'll will add the Hochtontreiber MH1 to my options. By the way, your link was not directly clickable because of the extra "." at the end. For the convenience of others, here the link again:
http://www.volkslautsprecher.com/html/mh1.html
Also, earlier, I had found another third-party direct replacement for the TC120 from Clofis in Netherlands:
Celeritas TD130R
But all these direct replacements use foam surrounds. If possible, I would like to avoid foam surrounds. I stay in a hot and humid location, and, with foam surrounds, I may need to repeat this exercise every 3-4 years.
thank you for you reply. I'll will add the Hochtontreiber MH1 to my options. By the way, your link was not directly clickable because of the extra "." at the end. For the convenience of others, here the link again:
http://www.volkslautsprecher.com/html/mh1.html
Also, earlier, I had found another third-party direct replacement for the TC120 from Clofis in Netherlands:
Celeritas TD130R
But all these direct replacements use foam surrounds. If possible, I would like to avoid foam surrounds. I stay in a hot and humid location, and, with foam surrounds, I may need to repeat this exercise every 3-4 years.
Hi again,
I suppose there are many options available, seas tweeters come to mind, Dynaudio and scanspeak too but i am no expert so let some who has actually tried it advise you... The Lali's use a seas bass-mid driver. BTW, the tweeter they used seems to be TC 90 K not the 120. If you don't already know it, http://www.acoustica.org.uk/impulse/h6mods.html have some info on modding the lali's and the H6 which shared common drivers .
Zaph audio made a tweeter group test here: http://www.zaphaudio.com/tweetermishmash/
Have fun
Tom
I suppose there are many options available, seas tweeters come to mind, Dynaudio and scanspeak too but i am no expert so let some who has actually tried it advise you... The Lali's use a seas bass-mid driver. BTW, the tweeter they used seems to be TC 90 K not the 120. If you don't already know it, http://www.acoustica.org.uk/impulse/h6mods.html have some info on modding the lali's and the H6 which shared common drivers .
Zaph audio made a tweeter group test here: http://www.zaphaudio.com/tweetermishmash/
Have fun
Tom
Tom,
thanks for the acoustica h6mods link. The series crossover connection looks very promising and I'll want to try it out in the future.
The original tweeter on the Impulse Lali is almost certainly the TC120K. The face plate is 120x120mm, not the 92x92mm of the TC90. And the magnet is humongous (for a tweeter).
From what little I know so far by looking at the specs sheets, the SEAS tweeters (e.g. the 27TDFC) look most suitable. The Fs is suitably low at 550Hz, and the impedence peak is also low and smooth. But the linear coil travel is only 0.5mm p-p; more would be better of course.
thanks for the acoustica h6mods link. The series crossover connection looks very promising and I'll want to try it out in the future.
The original tweeter on the Impulse Lali is almost certainly the TC120K. The face plate is 120x120mm, not the 92x92mm of the TC90. And the magnet is humongous (for a tweeter).
From what little I know so far by looking at the specs sheets, the SEAS tweeters (e.g. the 27TDFC) look most suitable. The Fs is suitably low at 550Hz, and the impedence peak is also low and smooth. But the linear coil travel is only 0.5mm p-p; more would be better of course.
I wouldn't suggest the Vifa tweeter for your application. While the fs is low, harmonic distortion is high at frequencies below 2000hz. You would have to go with a higher order crossover on this one. Still a good tweeter.
My suggestion would be the Accuton C23-6 assuming you have some cash to spend. I have a pair w/ 1st order crossovers and they work great.
My suggestion would be the Accuton C23-6 assuming you have some cash to spend. I have a pair w/ 1st order crossovers and they work great.
hehe, embarrassed to say, I did try my luck earlier with the Vifa XT25. And no, it didn't work well, just as Big Smooth said in the preceding note.
XT25 fitted on 120x120mm face plate:
BigSmooth,
yes, the Accuton C23-6 was another on my list, and your note validates it. The impedence plot looks very good. The sensitivity at 89.5dB is just a bit lower than I like (the Impulse Lali is 91dB while the Focal TC120K itself is 93.5dB), but I can live with it. I still need to think more about the money part though 🙂
One question - beneath the grill can you tell if the Accuton's suspension is foam or rubber? Thanks.
XT25 fitted on 120x120mm face plate:
An externally hosted image should be here but it was not working when we last tested it.
BigSmooth,
yes, the Accuton C23-6 was another on my list, and your note validates it. The impedence plot looks very good. The sensitivity at 89.5dB is just a bit lower than I like (the Impulse Lali is 91dB while the Focal TC120K itself is 93.5dB), but I can live with it. I still need to think more about the money part though 🙂
One question - beneath the grill can you tell if the Accuton's suspension is foam or rubber? Thanks.
Basically ANY of the Seas tweeters with low Fs (around 500) will work very nicely with low order x-os !!
I'll check tonight to see if the surround is foam or not.
Do you see any L-Pad in the crossover you have on your T120K?
Do you see any L-Pad in the crossover you have on your T120K?
It's very difficult to see what the surround is without prying off the grills. I really don't want to try that.
From what I can see, i'm guessing it is some type of treated fabric. That's just a guess....
From what I can see, i'm guessing it is some type of treated fabric. That's just a guess....
Member
Joined 2004
Strange... i am the first to mention morel tweeters, these are build to handle first order crossovers.
groet Roland
groet Roland
Alex S said:
With the values given (3.3µF), the tweeter is crossed over at about 6000-8000Hz, which is fairly high. I would say that most tweeters can be crossed over at that frequency with a first order XO, as long as the resonance frequency is low enough (1500Hz or less), which is the case of many tweeters. Look for some good 19mm (3/4"); since the Focal was known to have a level increase towards high frequencies, small VC type would match better (because they can have similar behavior).
Many Seas or Vifa (sorry, Peerless V-line...) can do that, but go and have a look to some classy tweeter from Hiquphon (www.hiquphon.dk), which are most probably the finest 19mm tweeters available
.Rgds,
- dan
Have to agree with Roland - the Morels, especially the mdt33 and supreme 110 are designed for 1st order filters. Other options are Hiquphons, Dynaudio d28, d21, or esotec d260 still appearing on ebay.
The sound of a focal vs. seas, morel, etc. is a bit different.
At around 90db offering good value and similar sound I'd look to the Visaton KE25SC.
In the US:
http://gallery.bcentral.com/GID4956567P4701844-VISATON-Tweeters/Tweeter-KE25SC.aspx
At around 90db offering good value and similar sound I'd look to the Visaton KE25SC.
In the US:
http://gallery.bcentral.com/GID4956567P4701844-VISATON-Tweeters/Tweeter-KE25SC.aspx
ScottG said:
Agree with Scott. A friend of mine bought them and they can easily withstand a comparison with some high tech expensive Scan-speak tweeters with their musicality. Very smooth though, quite the opposite of the original Focal. A bargain.
- dan
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