Greeting speaker lovers!
I am need of help from the community. I am looking for the original T/H parameters for a VIFA M18SJZ4-04. It came out of a Sony SS-X70ED. Both are drivers are toast in each cabinet. I can normall come up with my own T/H but given they are damage, this is not possible. I have looked everywhere for the data sheet but it eludes me.
Any assistance is welcomed!
I am need of help from the community. I am looking for the original T/H parameters for a VIFA M18SJZ4-04. It came out of a Sony SS-X70ED. Both are drivers are toast in each cabinet. I can normall come up with my own T/H but given they are damage, this is not possible. I have looked everywhere for the data sheet but it eludes me.
Any assistance is welcomed!
Looks like a special OEM shielded version of the Vifa M18WO-09-08. Does it look like the dimensions in the attached PDF.
Maybe if you add some more photos someone may be of help. If you need to replace drivers in the Sony speaker, you may want to reverse engineer the design to find a suitable driver
Maybe if you add some more photos someone may be of help. If you need to replace drivers in the Sony speaker, you may want to reverse engineer the design to find a suitable driver
Thank you! Yes, dimensions of basket are the same. The reversed pole magnet they place to make it magnetically shielded and that it is a 4 ohm speaker will undoubtedly have varied T/H from this one. I have found others similar including Scanpeak which have the identical basket and marking on the rubber surround. Adding extra pictures is definitively a good idea.
Attachments
Thank you! Yes, I have also looked at this one. Getting close. This double reverse pole magnet for magnetic shielding will undoubtedly have varied T/H. Perhaps I am expecting too much and at some point will have to accept defeat or find someone who has this same driver and have tested themselves and determined their own T/H. I just don't want to throw any alternative just yet. I mean, look at the structure of the speaker cabinet they created. The cabinet weighs 60lbs or 23kg and it is dead, dead quiet/silent.
Attachments
Just an idea, a few months ago I removed the complete cone assembly from a M22WR, an unit in the same series as your M18. It happened to have corroded magnesium that got into the gap and blocked the voice coil. With some care, ingenuity and household tools I got it running pretty well again. Magnesium corrosion happens quite often with those drivers. Could be yours have that too. Unless you are sure they have bottomed out a few times too many that is…
Thanks for sharing. To the best of my knowledge they have not bottomed out. I have found a used M18SJZ4-04 online. I spoke to owner and it came out of the same speaker and shares that it works with not scratching of vc. So, I may purchase it, only wants $20. I can then obtain T/S parameters and determine how to best procedd for alternative replacement.
Have you measured the DCR of the woofers as should be around 3R? That will tell you if it's an open or closed circuit.
If the cone is not frozen you can try moving the cone in and out with the cone facing down and then try and power it for a while facing down with a low frequency tone.
I can't see any white magnesium corrosion on the basket.
If the cone is not frozen you can try moving the cone in and out with the cone facing down and then try and power it for a while facing down with a low frequency tone.
I can't see any white magnesium corrosion on the basket.
Send both for repair/rewinding and then measure the TS parameters. It will certainly not be the same TS parameters as the factory ones.
This was on my ‘patient’. When the paint comes off the magnesium, with moist from the air, turns into expanded white stuff. In this case it clogged the magnet gap and blocked the voice coil. No visible signs on the outside though.
I have not dissasembed the driver. I was not planning on doing this type of surgery that I have never performed. I can't find the T/S data anywhere for this driver. I am hoping someone on this forum has it or has tested the same driver and obtained the T/S.
Since the driver is open circuit AND voicecoil seized, I think it's a goner. Voicecoil is a bird's nest to my guess. Sorry!
Your $20 replacement seems a plan.
I looked this floorstanding speaker up for due diligence:
https://yabb.jriver.com/interact/index.php?topic=113798.0
It seems the specs are 450Hz and 3500Hz crossover. Might be a three way or a 2.5 way IMO. 4 ohms and a high 89dB loudness.
Maybe a kevlar or fibreglass midrange. Obviously a reflex bass, so QTS around 0.35- 0.4 in T/S terms. Reflex is less critical than most people make out, IMO.
Not quite clear to me if the bass and mid drivers are 180mm chassis, but you can find out.
If the paper bass is 180mm, that might be a fairly easy replacement with Peerless, Vifa or Scanspeak drivers all bundled up as Tymphany these days.
But that is more expensive and more complicated.
Troels Gravesen has done this sort of thing:
http://www.troelsgravesen.dk/Peerless_HDS830875.htm
If it was me, I would have traced the crossover to find out what is going on here, but you seem to have a good plan anyway. Just replace with second hand.
Best, Steve,
Your $20 replacement seems a plan.
I looked this floorstanding speaker up for due diligence:
https://yabb.jriver.com/interact/index.php?topic=113798.0
It seems the specs are 450Hz and 3500Hz crossover. Might be a three way or a 2.5 way IMO. 4 ohms and a high 89dB loudness.
Maybe a kevlar or fibreglass midrange. Obviously a reflex bass, so QTS around 0.35- 0.4 in T/S terms. Reflex is less critical than most people make out, IMO.
Not quite clear to me if the bass and mid drivers are 180mm chassis, but you can find out.
If the paper bass is 180mm, that might be a fairly easy replacement with Peerless, Vifa or Scanspeak drivers all bundled up as Tymphany these days.
But that is more expensive and more complicated.
Troels Gravesen has done this sort of thing:
http://www.troelsgravesen.dk/Peerless_HDS830875.htm
If it was me, I would have traced the crossover to find out what is going on here, but you seem to have a good plan anyway. Just replace with second hand.
Best, Steve,