@IamJF Did they happen to improve the HD around the 1k area with the newer version? The old ones I tried had a noticeable hiccup around there which drew attention to itself male with vocals. If it wasn't for this, the MD60N would be a very efficient, useful driver for its size. The 1/4 WL resonance clearly coincides with the rear chamber tube depth.
If the metal screen behind the dome is accessible, it can be covered with a low density felt for better absorption. The way ScanSpeak uses their felt makes the sound bounce around inside the back motor first before its attenuated, which isn't the best design IMO.
If the metal screen behind the dome is accessible, it can be covered with a low density felt for better absorption. The way ScanSpeak uses their felt makes the sound bounce around inside the back motor first before its attenuated, which isn't the best design IMO.
so what does everybody think the best freely available option is atm ? the cheaper morel , the scanspeak or something else
As you see with the postet measurements - there is no problem with distortion at 1kHz! They sound detailed and clean.
Metal screen is accessible but not sure if there is room for something on it. It is pretty rigid with big holes in it. I can't find the photos I took ...
Yeah, it is unfortunate that there's no US Bliesma distributor. I've ordered a few things from Solen and it's been a good experience overall. @profiguy, you've mentioned some importing issues. Would these apply to the M74A/S/P?
By importing issues, I'm referring to cost and delay related to getting them through customs (not anything that is Solen's fault).
Audio-Hifi usually has stock, free worldwide delivery and sells below retail. I bought a pair of T34A from there without any problem. The only ones that are difficult to find are the Beryllium ones, most manufacturers are struggling to make Be drivers since Materion pulled the foil that they were using.
https://audio-hi.fi/en/bliesma-m-33.html
https://audio-hi.fi/en/bliesma-m-33.html
Hi Profiguy, got pretty excited when I saw this thread with some specific D7608 info. I designed some 3w floorstanders using the Scanspeak 3" a few years ago & am always keen to improve them. (did this based on yet another set of 3w's I did way back that also used them - I thought they were magic on piano & other instruments)
Anyways I noted your comments on Qts values being around 1.5 stock - specs say 1.7. So I went back to my DATS driver measurements. These are reproduced below and gave Qts as around 0.6.
My D7608s were purchased ~ 2019 FWIW. I would be interested to hear your thoughts on the apparent discrepancy.
Anyways I noted your comments on Qts values being around 1.5 stock - specs say 1.7. So I went back to my DATS driver measurements. These are reproduced below and gave Qts as around 0.6.
My D7608s were purchased ~ 2019 FWIW. I would be interested to hear your thoughts on the apparent discrepancy.
Attachments
The old H304 (fabric dome) had a greenish Nomex(Aramid similar to Kevlar) carrier for the coil , giving low mech losses! (non-inductive coil carrier)
Btw - something negative on the H304 , the whole thing is mechanically very unstable in itself , like the cheap 25mm dome tweeters from Audax/France ... comparing just the naked drivers SEAS H304 (with original cup) vs Dynaudio D76AF , the H304 sounds very coloured!
M74S also has a pretty thin membrane - I could see it deform with some impulses from switching! That's for sure wanted for the sound ideal they wanted to achieve compared to the other 3 versions. And to be honest - in the range of 450-2000Hz I could detect differences to M74A but not like day and night. These would probably be more obvious when you use the domes up to 3-3,5kHz.
Once I repaired the old ATC mid dome , this older model had long coil 10mm and 5mm deep gap , it has also a 3mm thick balsa wood ring along the upper edge of the carrier . Later they reversed the setup and used a 10mm deep gap and a 5mm coil , but no balsa no more ...
But the fabric was thicker and coating too , plus broad surround , a real power horse!
But the fabric was thicker and coating too , plus broad surround , a real power horse!
Ianbo, those Dats measurements are free air with no driver breakin. It is my understanding that the specs given relate to those conditions - eg, Qts indicates "total Q of driver at Fs including all driver resistances" only. The parameters for an enclosed driver would be Qtc being "total Q of system at Fs including all system resistances"
But maybe I'm wrong about this ?
(FWIW I have the D7608's mounted in a ~1.5L sub enclosure lined with egg crate foam)
But maybe I'm wrong about this ?
(FWIW I have the D7608's mounted in a ~1.5L sub enclosure lined with egg crate foam)