Hi, I have a pair of Visaton Alto III (old version, 1990s). For some reason, one of the speakers midrange (DMR124) having a crack sound. It happened to another one before but I found the part to replace at that time (20 years ago). I try to find the part again but unfortunately I can't find any (i believe this part is discontinued for long time). Is that any other way that I can find this part? or any suggestions that I can use a different Brand mid-range to replace that? Thank you
Visaton Forum under Marktplatz(Buy Sell) or ask in General(Allgemeines Diskussionsforum) for a replacement recommendation.
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I'm not a fan of buying old second-hand drivers on eBay. They are often worn out.
This old tweeter is probably nothing special. First step is always to measure the mounting plate size, often 104mm, and the cutout hole size to see what will fit.
You might get lucky and find the ferrofluid has just dried out and turned into solid gunge. Easy enough to replace, since most tweeters come apart. Blue Aran have it in the UK.
The serious DIYer would download Boxsim: Downloads
And import a similar projekte into the folder, and modify it:
https://boxsim-db.de/alto-iii-c/
I'm not sure which of these are appropriate, but some of them will work.
Dome Tweeters
Dome Midranges
I expect the crossover values are marked in a kit like this. You might have to change a couple of resistors. See, it's a homework problem really. You have to inspect first. Boxsim has an archive of old drivers, I found a thing called a DMR120-4. You could then change it something else, and see what needs adjusting for loudness.
This old tweeter is probably nothing special. First step is always to measure the mounting plate size, often 104mm, and the cutout hole size to see what will fit.
You might get lucky and find the ferrofluid has just dried out and turned into solid gunge. Easy enough to replace, since most tweeters come apart. Blue Aran have it in the UK.
The serious DIYer would download Boxsim: Downloads
And import a similar projekte into the folder, and modify it:
https://boxsim-db.de/alto-iii-c/
I'm not sure which of these are appropriate, but some of them will work.
Dome Tweeters
Dome Midranges
I expect the crossover values are marked in a kit like this. You might have to change a couple of resistors. See, it's a homework problem really. You have to inspect first. Boxsim has an archive of old drivers, I found a thing called a DMR120-4. You could then change it something else, and see what needs adjusting for loudness.
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Thank you. I did check with this website before but unfortunately they don't ship internationally (i am in Canada)
I saw it myself, but I thought it was overpriced.
Anyway, that's just too easy. 😀
I also smelt a rat with the whole design. Why does the mid keep blowing?
Because they are using a 4 ohm 38mm dome mid to keep the level up. It's getting pushed too hard at high level. the Fs at 700Hz could be a problem. The impedance isn't pretty.
You have powerful tools to redesign with Visaton. Maybe why they changed to a 4" cone mid in the 3c.
Anyway, that's just too easy. 😀
I also smelt a rat with the whole design. Why does the mid keep blowing?
Because they are using a 4 ohm 38mm dome mid to keep the level up. It's getting pushed too hard at high level. the Fs at 700Hz could be a problem. The impedance isn't pretty.
You have powerful tools to redesign with Visaton. Maybe why they changed to a 4" cone mid in the 3c.
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This guy is selling a pair for 40€ only in a rectangular version.
Visaton DM 115 NG 4 Ohm High End Mitteltner (Raritt & Klassiker) NEU | kalaydo.de
The TSPs for the original are available if you do some googling; unfortunately the available Visaton dome mids are quite different, I think the Dayton one may be closer
I feel like Billy-No-Mates in this thread, so far. But I wouldn't underestimate the problems of replacing a dome midrange with another model. It's a huge redesign.
Either you get a replacement mid diaphragm, or you rebuild that poor design entirely.
Which is quite a good investment for the next 20 years.
IMO, a better design here is the bass/tweeter/supertweeter idea. Actually not too hard with the Visaton Boxsim modeller.
It's all been done before. These Spendor variations are what I call classic designs. They all work well. An 8" bass or two 6.5" basses pretty much end up in the same place. But a higher crossover on the big tweeter in the second model.
Either you get a replacement mid diaphragm, or you rebuild that poor design entirely.
Which is quite a good investment for the next 20 years.
IMO, a better design here is the bass/tweeter/supertweeter idea. Actually not too hard with the Visaton Boxsim modeller.
It's all been done before. These Spendor variations are what I call classic designs. They all work well. An 8" bass or two 6.5" basses pretty much end up in the same place. But a higher crossover on the big tweeter in the second model.
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re:'It's a huge redesign.' - I agree, I'd say given the age of the speakers, the OP's got his money's worth, time to move on.... re-use the boxes to build the new version? (Alto III C)
According to the Visaton forum the crossover of the Alto III looks like this:
The 4 ohm writing next to the midrange driver is questionable. The driver most probably is 8 ohm, but the crossover drops the impedance significantly.
Attached to post #33 of the Visaton forum pulsar99 even provides a Boxsim project: Alto3(a) Optimieren? - Seite 3 - Visaton Diskussionsforum
The design is decent IMO, perhaps impedance is a bit low. 🙂
An externally hosted image should be here but it was not working when we last tested it.
The 4 ohm writing next to the midrange driver is questionable. The driver most probably is 8 ohm, but the crossover drops the impedance significantly.
Attached to post #33 of the Visaton forum pulsar99 even provides a Boxsim project: Alto3(a) Optimieren? - Seite 3 - Visaton Diskussionsforum
The design is decent IMO, perhaps impedance is a bit low. 🙂
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No. Everything I've seen so far, suggests to me this is a 4 ohm nominal 38mm. soft-dome mid. And I'd be very surprised if those basses are not 8 ohms nominal. 😀
But at a certain point I stop the guesswork and start looking and measuring.
The picture below is a Morel CAT298 8 ohms nominal tweeter which I have lying around.
Well, I measured 5.1 ohms DC resistance on the 200 ohm scale, Morel say 5.2. Makes sense. 😎
You can buy meters a bit less sophisticated than mine for about £5 or 10 Euros. But adequate. 4 ohms nominal is usually about 3 ohms DC resistance.
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I downloaded that Alto project from the Visaton Forum.
I checked the DCR of the drivers used. But I'm not saying that's what Visaton used in their or denle's kit, because it's a terrible design. You don't wire two 4 ohm basses in parallel unless you want to destroy your amp. And if you drive a 8 ohm mid too hard, you have nowhere to go to avoid the 3kHz dip in impedance that gave the Gale 401 such a reputation for frying amps.
The 38mm mid is crossed far too high. 5kHz would make more sense, because the soft dome breakup resonance is clearly around 9kHz. The super tweeter is some sort of variation on the tiny DTW-72 mylar type, which is not a bad choice. As I predicted, there are power handling problems with the mid low down and especially at 3kHz.
Boxsim has compatibility problems with old projects. I don't think early versions had an optimiser, so you have to do it manually with most of the old driver files, which are incomplete.
denle, my friend, you are probably wondering what you have let yourself in for here. You need to check the drivers, wiring and crossover. See what you've got. If you've got two old W170S-4, they might make more sense wired in series. Of course that means some work on mid and tweeter. But doable. A 6dB quieter speaker, but better, I think.
I checked the DCR of the drivers used. But I'm not saying that's what Visaton used in their or denle's kit, because it's a terrible design. You don't wire two 4 ohm basses in parallel unless you want to destroy your amp. And if you drive a 8 ohm mid too hard, you have nowhere to go to avoid the 3kHz dip in impedance that gave the Gale 401 such a reputation for frying amps.
The 38mm mid is crossed far too high. 5kHz would make more sense, because the soft dome breakup resonance is clearly around 9kHz. The super tweeter is some sort of variation on the tiny DTW-72 mylar type, which is not a bad choice. As I predicted, there are power handling problems with the mid low down and especially at 3kHz.
Boxsim has compatibility problems with old projects. I don't think early versions had an optimiser, so you have to do it manually with most of the old driver files, which are incomplete.
denle, my friend, you are probably wondering what you have let yourself in for here. You need to check the drivers, wiring and crossover. See what you've got. If you've got two old W170S-4, they might make more sense wired in series. Of course that means some work on mid and tweeter. But doable. A 6dB quieter speaker, but better, I think.
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re: 'do you mean this one?' - this one's closer to the linked TSPs: RS52AN-8 2" Dome Midrange 8 Ohm Specification Sheet
If it's close enough impedance wise perhaps it could be a drop in if a zobel is wired across it?
However, without impedance plots of the original, it's all guesswork, and the series resistor would also need tweaking if there's a marked difference in sensitivity....
If it's close enough impedance wise perhaps it could be a drop in if a zobel is wired across it?
However, without impedance plots of the original, it's all guesswork, and the series resistor would also need tweaking if there's a marked difference in sensitivity....
FWIW, PeteMcK, here's the boxsim plot of the Visaton DMR 124 in a test enclosure. DCR=6.1 ohms. Le=0.3mH as parameter. 38mm dia, acoustic centre 13mm back.
Make of it what you will! 🙂
It's been a fun thread for me. I've learned more about Boxsim. There are a couple of Alto III alternative projects, in the thread that Dissi found, with the M10 closed back 4" cone mid and the DTW72 mylar dome. Maybe it's doable?
M 10 - 8 Ohm
DTW 72 - 8 Ohm
Make of it what you will! 🙂
It's been a fun thread for me. I've learned more about Boxsim. There are a couple of Alto III alternative projects, in the thread that Dissi found, with the M10 closed back 4" cone mid and the DTW72 mylar dome. Maybe it's doable?
M 10 - 8 Ohm
DTW 72 - 8 Ohm
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