Soundimports , I requested email notification which I got yesterday ... so I thought letting you know that would be appreciated here 🙂
https://www.soundimports.eu/en/hivi-dm-7500.html
Then I found this video that shows the inner structure of this driver :
Somewhere I saw a picture of the updated dome midrange from Tang Band which showed a MUCH too small pole vent diameter that needs lots of stuffing for damping!
But what makes me wonder is why the guy in the video above have not used the six screws for detaching the HiVi dome midrange!?
Little bad secret here veiled?
Would be nice if Soundimports offer also the new GRS Ribbons which seem to be build by Fountek .
Nice price too :
https://www.parts-express.com/GRS-RT1.R-8-Hi-Res-Neo-Ribbon-Tweeter-8-Ohm-272-202
Btw - the data sheet mentioned 30um ribbon thickness ... previous ribbons by Fountek had 15um foils so they probably have just doubled the foil for more robustness und less distortion! (and less susceptible for inner reflections)
Unless further confirmed it looks like Dayton/GRS/Fountek did some progress stepping in the right direction - congrats!
Big Audio Yam-Yam 🙂
https://www.soundimports.eu/en/hivi-dm-7500.html
Then I found this video that shows the inner structure of this driver :
Somewhere I saw a picture of the updated dome midrange from Tang Band which showed a MUCH too small pole vent diameter that needs lots of stuffing for damping!
But what makes me wonder is why the guy in the video above have not used the six screws for detaching the HiVi dome midrange!?
Little bad secret here veiled?
Would be nice if Soundimports offer also the new GRS Ribbons which seem to be build by Fountek .
Nice price too :
https://www.parts-express.com/GRS-RT1.R-8-Hi-Res-Neo-Ribbon-Tweeter-8-Ohm-272-202
Btw - the data sheet mentioned 30um ribbon thickness ... previous ribbons by Fountek had 15um foils so they probably have just doubled the foil for more robustness und less distortion! (and less susceptible for inner reflections)
Unless further confirmed it looks like Dayton/GRS/Fountek did some progress stepping in the right direction - congrats!
Big Audio Yam-Yam 🙂
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It looks great on paper.
It is insane what HiVi can make and for how much money.
As for unscrewing for deattaching - i think that those screws center the voice coil into the magnet gap. If you mess up that, recentering will be a challenge.
It is insane what HiVi can make and for how much money.
As for unscrewing for deattaching - i think that those screws center the voice coil into the magnet gap. If you mess up that, recentering will be a challenge.
I couldn't see the presence of a copper cap or was I missing something?
The TB might look as if the pole vent is too small but if it measures like that old one did then there's no problem.
The TB might look as if the pole vent is too small but if it measures like that old one did then there's no problem.
The guy is saying that he ordered 10 pieces of DM7500 and only one measured as it should. Others had distortion spikes at 400-600-1000-1200Hz. He opened the dome midrange and saw shavings in the magnetic gap. He also noticed that impregnation thickness was not the same in all midranges. Also, the backchamber in couple of pieces was whistling because of lack of glue.
So, quite a few QC issues for the first batch. Hopefully, it will be resolved since he said that the one that measured with no problems had very low distortion down to 300Hz
So, quite a few QC issues for the first batch. Hopefully, it will be resolved since he said that the one that measured with no problems had very low distortion down to 300Hz
https://hificompass.com/en/speakers/measurements/tb-speakers/tangband-75-1558se
That rising 5th harmonic with decreasing frequency on the TB? No thanks.
So both the TB and Hivi have issues. Hopefully Hivi will resolve their QC. But stuff in the magnetic gap is loudspeaker construction 101. How do you get it right for other drivers but but not this? Unless it's automation issues. Still they got through QC when they shouldn't have.
That rising 5th harmonic with decreasing frequency on the TB? No thanks.
So both the TB and Hivi have issues. Hopefully Hivi will resolve their QC. But stuff in the magnetic gap is loudspeaker construction 101. How do you get it right for other drivers but but not this? Unless it's automation issues. Still they got through QC when they shouldn't have.
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So far I haven't read any bad reputation about HiVi drivers here and everywhere ... even at ASR they are praising the 50mm domes! (ferrite/neo)
Some not-so-minor issues are quite often in most drivers even the expensive ones!
Let's pile them up here and have a little bash party 🙂
Some not-so-minor issues are quite often in most drivers even the expensive ones!
Let's pile them up here and have a little bash party 🙂
The 1558 has been updated recently by this one , see also PDF for convenience :
http://www.tb-speaker.com/products/75-1558sh#tab-446
http://tb-speaker.com/uploads/editor/files/06 VC-June-(75-1558SH P25~P27).pdf
SB Acoustics has also solved the issues in their 60mm model .
About being happy with copper or not - down there in the dungeons of sound is harmonic sweetness the exception , regarding distortion - the torture never stops down there 🙂
Torture Never Stops : FZ gave us a few sketchy impressions ...
This one in the YT links sounds okay like the original LP but for many years a defective digital master was used also some other releases ... maybe 10years ago they started true remasters from the original analog master tape ... but hard to be detected on the CD box ... for the YOU ARE WHAT YOU IS (YAWYI) album I remember the name of the recording engineer Spencer Chrislu , on other corrected albums there are 1 or 2 of the other engineers were mentioned regarding remastering sorry forgot their names ....
http://www.tb-speaker.com/products/75-1558sh#tab-446
http://tb-speaker.com/uploads/editor/files/06 VC-June-(75-1558SH P25~P27).pdf
SB Acoustics has also solved the issues in their 60mm model .
About being happy with copper or not - down there in the dungeons of sound is harmonic sweetness the exception , regarding distortion - the torture never stops down there 🙂
Torture Never Stops : FZ gave us a few sketchy impressions ...
This one in the YT links sounds okay like the original LP but for many years a defective digital master was used also some other releases ... maybe 10years ago they started true remasters from the original analog master tape ... but hard to be detected on the CD box ... for the YOU ARE WHAT YOU IS (YAWYI) album I remember the name of the recording engineer Spencer Chrislu , on other corrected albums there are 1 or 2 of the other engineers were mentioned regarding remastering sorry forgot their names ....
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Bare in mind that this guy said he bought it from Aliexpress, not authorized vendor. It is not uncommon that factory rejects meant for recycling center to end up on aliexpress. It looks like that to me since you really need to work on it to have 90% rejects in production 🙂
What's interesting is that Zaph's measurements of the original TB didn't have that rising 5th harmonic. Well they did stop making the original for a reason.
Ali's the Ebay of the East isn't it?
I have enough challenges with the official distributor of authentic products (like them sending me a completely wrong parts), so I try to avoid unofficial / grey markets,,,
I have enough challenges with the official distributor of authentic products (like them sending me a completely wrong parts), so I try to avoid unofficial / grey markets,,,
You can not extrapolate its quality with the former measurements. Diyers have already noticed quality went down on some units like their isodynamic line for instance.
When all the war mess will end I am looking forward one sent his new Hivi dome to Hificompass for a proper measurement protocol. As the new 2.5" iterration dome from SB Acoustics.
When all the war mess will end I am looking forward one sent his new Hivi dome to Hificompass for a proper measurement protocol. As the new 2.5" iterration dome from SB Acoustics.
They look exactly like my two Fountek Neo CD 3.0, so are they identical, just offered under a different name? 🤔
Many greetings,
Azrael
There is at last 1 difference - previous model had 15um thin aluminium foil mentioned in the data sheet , now it is 30um - maybe they just doubled the foil and bonded both foils to get more extra strength!?
But thicker foil could mean higher frictional losses , and/or less distortion , probably higher reliability at elevated levels , hard to guess without practical experience and hardcore testing!
This comparison is quite shocking :
I have a smaller Fountek here and it sounds just like the bigger brother in the video!
Maybe a filter network will change the sound character for the better ...
The RAAL ribbon has a very low primary inductivity (intended) of the inbuild transformer so when you put a capacitor in series you get a 12dB HP-Filter with pretty high cutoff , maybe this explains the much different sound of the RAAL in the video!
happy audioworx
But thicker foil could mean higher frictional losses , and/or less distortion , probably higher reliability at elevated levels , hard to guess without practical experience and hardcore testing!
This comparison is quite shocking :
I have a smaller Fountek here and it sounds just like the bigger brother in the video!
Maybe a filter network will change the sound character for the better ...
The RAAL ribbon has a very low primary inductivity (intended) of the inbuild transformer so when you put a capacitor in series you get a 12dB HP-Filter with pretty high cutoff , maybe this explains the much different sound of the RAAL in the video!
happy audioworx
The new 9 inch SB Acoustics Woofer has a very nice FR at 30deg offaxis :
https://sbacoustics.com/product/95-satori-wo24tx-4-textreme/
https://sbacoustics.com/product/95-satori-wo24tx-4-textreme/