I noticed these Dynaudio mid domes for sale, made for Volvo or VW. Any use? What are they and is there any crossover design? I think the C70 midbass was 8" for Volvo.
https://www.ebay.co.uk/itm/255815930495?
https://www.ebay.co.uk/itm/255815930495?
Thank you, I checked with Vituixcad and got same results (if stuffing), so it is a little bass-shy in closed box, but it is a small box, which is a plus.
This would be very good with distributed subs, which I like, for a 4 ways or doubling up on the HM210C0 and doing 3.5 ways.
There seems to be an upgraded version of this driver, the HM210CP, which I found (only) here.
Are there any modern woofers that play low in smaller sealed boxes?
The classic woofers ("Acoustic Suspension") that did this were not very sensitive, so I expect that this would still be the case. They would typically have an Fs/Qte of less than 50, have heavier cones, have especially compliant suspensions and be unsuited for ported enclosures---because they need the captive air of a smallish sealed box to act as a major suspension element.
I think that I already mentioned my current project: A rebuild of an 8" Acoustic Research AR16, now a 3way, using the HIVI DMB-A dome mid. The box has 19 liters internal volume. 50hz is at the same level as 1000hz (there is a 2dB mid-dip built in, and the cabinet has a bass bump, starting at about 120hz and centered on 65hz; 65hz is about 3dB above the 1000hz level). Because it is sealed, the roll-off is 12dB/octave. Being sealed, 30hz is way down in level, but is still perceivable in music---no port output to mask the really low tones. Bass is tight and articulate. It does not play super loud, but is plenty loud for HIFI use in smaller rooms.
WAVEGUIDES
This current build utilizes a unity wave-guide---which is simply a surround made from a low angle molding that meets the baffle plane at about 1.5” away from the dome mid, and a little closer to the tweeter. It looks more like a picture frame than anything else. The moldings cause the mid to be physically recessed,and thus protected. The woofer is on its own .75" thick, arch top, supra baffle; the top of which forms the bottom side of the “picture frame”. The picture frame side and top moldings simply extend to the edge of the cabinet, with no corner radius. The drivers are fairly close to being physically “time-aligned”, with the mid flange sitting on top of the tweeter flange, which is also covered by a small “waveguide extension” which is part of a 5.2mm panel that also forms a rebate for the mid. There are no flanges exposed----all drivers are in rebates.
Response is very flat through the mids at 10 degrees off axis horizontal, with on axis and 20 degrees horizontal having complementary variations of +/- 1.5dB between 2khz and 7khz. 3khz is down on-axis, and up at 20deg off axis.
I liked the way my mono prototype sounded, but was unsure if a stereo pair would image well. I now have two prototypes that make a really nice sound-stage. There are surely systems that image more precisely, but I find all to be well placed,deep and enjoyable.
No major edge diffractions have been noticed. I had much more trouble with mid dome wave guides that were 7" round and had throats that were close to the dome. I experimented with loose moldings on a flat baffle and noticed good results in measurements, and no big problems, so the "picture frame" idea came into being. I did something similar on another build, but did actually use a round waveguide for the Dayton DC50FA dome mid.
I had made a 7” round wave guide that worked well on the (no longer available) Dayton DC 50 FA (was the DC50FA a copy of a Dynaudio mid?). I tried the same WG on the DMB-A mid. Due to the fact that it boosted the area below the (stubborn) on-axis dip of the raw driver at 4300hz, it promised to make the DMB-A harder to work with.
I think that the crossover is close to being fully tweaked, but----??? I wanted to cross at 4khz but ended up substantially lower, due to trouble getting the DMB-A to roll off smoothly on the top end.
The classic woofers ("Acoustic Suspension") that did this were not very sensitive, so I expect that this would still be the case. They would typically have an Fs/Qte of less than 50, have heavier cones, have especially compliant suspensions and be unsuited for ported enclosures---because they need the captive air of a smallish sealed box to act as a major suspension element.
I think that I already mentioned my current project: A rebuild of an 8" Acoustic Research AR16, now a 3way, using the HIVI DMB-A dome mid. The box has 19 liters internal volume. 50hz is at the same level as 1000hz (there is a 2dB mid-dip built in, and the cabinet has a bass bump, starting at about 120hz and centered on 65hz; 65hz is about 3dB above the 1000hz level). Because it is sealed, the roll-off is 12dB/octave. Being sealed, 30hz is way down in level, but is still perceivable in music---no port output to mask the really low tones. Bass is tight and articulate. It does not play super loud, but is plenty loud for HIFI use in smaller rooms.
WAVEGUIDES
This current build utilizes a unity wave-guide---which is simply a surround made from a low angle molding that meets the baffle plane at about 1.5” away from the dome mid, and a little closer to the tweeter. It looks more like a picture frame than anything else. The moldings cause the mid to be physically recessed,and thus protected. The woofer is on its own .75" thick, arch top, supra baffle; the top of which forms the bottom side of the “picture frame”. The picture frame side and top moldings simply extend to the edge of the cabinet, with no corner radius. The drivers are fairly close to being physically “time-aligned”, with the mid flange sitting on top of the tweeter flange, which is also covered by a small “waveguide extension” which is part of a 5.2mm panel that also forms a rebate for the mid. There are no flanges exposed----all drivers are in rebates.
Response is very flat through the mids at 10 degrees off axis horizontal, with on axis and 20 degrees horizontal having complementary variations of +/- 1.5dB between 2khz and 7khz. 3khz is down on-axis, and up at 20deg off axis.
I liked the way my mono prototype sounded, but was unsure if a stereo pair would image well. I now have two prototypes that make a really nice sound-stage. There are surely systems that image more precisely, but I find all to be well placed,deep and enjoyable.
No major edge diffractions have been noticed. I had much more trouble with mid dome wave guides that were 7" round and had throats that were close to the dome. I experimented with loose moldings on a flat baffle and noticed good results in measurements, and no big problems, so the "picture frame" idea came into being. I did something similar on another build, but did actually use a round waveguide for the Dayton DC50FA dome mid.
I had made a 7” round wave guide that worked well on the (no longer available) Dayton DC 50 FA (was the DC50FA a copy of a Dynaudio mid?). I tried the same WG on the DMB-A mid. Due to the fact that it boosted the area below the (stubborn) on-axis dip of the raw driver at 4300hz, it promised to make the DMB-A harder to work with.
I think that the crossover is close to being fully tweaked, but----??? I wanted to cross at 4khz but ended up substantially lower, due to trouble getting the DMB-A to roll off smoothly on the top end.
Has Parts Express carried much Visaton in the past? There are many Visaton drivers listed on their "new" page.
Europe may suddenly be a more attractive market for sourcing parts. I also saw they were carrying Beyma drivers.
I think they may have had this popular wave guide for about 1.5 years:
Visaton WG 148 R Round Waveguide for 1” Dome Tweeters
VisatonPart #292-768
Model: WG 148 R
Somewhere early in this thread there was discussion about this, I think. Volvo was the car specifically mentioned, as I recall.
PE also has this one:
I wonder if the shallow dome profile might work more easily with wave-guides.
Part #292-7803
Model: G 25 FFL
The Visaton G 50 FFL is a high-end 50 mm (2") fabric dome midrange driver designed for precise audio reproduction between 800 and 7,000 Hz. Its optimized dome shape, featuring a damping coating and highly damped surround, ensures a linear frequency response with minimal partial oscillations, delivering clear and accurate midrange sound. The powerful magnetic drive and ferrofluid-cooled voice coil contribute to high efficiency and substantial power handling, making it suitable for high-fidelity audio applications.
Key Features
sorry I cut off the frequency scale, the impedance peak is just under 500hz here.
I wonder if the shallow dome profile might work more easily with wave-guides.
NEW
VisatonPart #292-7803
Model: G 25 FFL
The Visaton G 50 FFL is a high-end 50 mm (2") fabric dome midrange driver designed for precise audio reproduction between 800 and 7,000 Hz. Its optimized dome shape, featuring a damping coating and highly damped surround, ensures a linear frequency response with minimal partial oscillations, delivering clear and accurate midrange sound. The powerful magnetic drive and ferrofluid-cooled voice coil contribute to high efficiency and substantial power handling, making it suitable for high-fidelity audio applications.
Key Features
- Frequency response from 300 to 12,000 Hz for extended midrange reproduction
- Resonance frequency at 455 Hz contributing to clear midrange performance
- Peak power handling of 180 W with a 12 dB/octave high-pass filter at 800 Hz for robust performance
- Opening angle of 180° at 4,000 Hz for wide sound dispersion
- Ferrofluid-cooled voice coil for enhanced efficiency and power handling
sorry I cut off the frequency scale, the impedance peak is just under 500hz here.
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The DSM50FFL has been around in various iterations since at least the early 1990s. I even still have a pair in stock that I should do something with. 🙂
So this is a titanium version of an old design? How does the one you have measure?
All versions had titanium diaphragms. There are differences in the surrounds and others, for example, which often prevent the swing unit of one version from being mounted on the engine of another.
I have the current version, which is probably also offered by PartsExpress. However, I have not yet measured it.
I have the current version, which is probably also offered by PartsExpress. However, I have not yet measured it.
Yes, the G25FLL works great wih WG148r, as seen here
https://www.visaton.de/en/products/2-way-speakers/studio-2
But all the models are new to the American market, not recently released. Quite old actually.
The G50 FLL was used by PMC in some models.
https://www.visaton.de/en/products/2-way-speakers/studio-2
But all the models are new to the American market, not recently released. Quite old actually.
The G50 FLL was used by PMC in some models.
I just got ahold of a pair of these DSM50FFLs in a trade deal.
I'm looking forward to testing them. They've been around since the 80s, but have gone through 2 updates. The newest one has much higher quality ferrofluid and tighter machining tolerances. You can also get repair diaphragm for them, so thats a plus IMO. The availability of spare diaphragms is a big deal and an indication the driver is engineered to a higher degree of precision, as the diaphragm has to be very accurately keyed to be installed by inexperienced end users.
I've built a few systems with this mid in its older design version. It sounds very transparent and detailed without being overly harsh, aggressive or fatiguing. That's a hard act to pull off with a titanium dome, but they managed to do it.
The DSM25FFL is the matching tweeter in the series. Its also very good, but compared to many other tweeters, its about average. Luckily, above 5k or so most domes will sound pretty decent, being we can't perceive upper harmonics that well once we go past 5k or so. The second order harmonic to 5k is 10k, so its already closer to the upper hearing limits for most peoole.
Well, I just measured them on my DATS and the results aren't promising on these new ones. The two units don't match well at all. TSPs are all over the place. Either one has more FF in it than another or theres a proben with dampening. I specifically don't like the secondary peaks. One of them has only a single peak and the other has little 2 peaks.
I apologize for the hazy pics.
I apologize for the hazy pics.
Yeah its a shame that this slips past QC. Its not like its a cheap $30 Hivi dome mid. Its actually $120 new.
@A4eaudio I'm not on a PC for the forums. I use an android device. My PC is completely segregated and offline from the internet accept for necessary downloads. I dont want to contaminate the PC with potential online junk and malware. The Android is encrypted both ways, so its safer for online stuff.
@A4eaudio I'm not on a PC for the forums. I use an android device. My PC is completely segregated and offline from the internet accept for necessary downloads. I dont want to contaminate the PC with potential online junk and malware. The Android is encrypted both ways, so its safer for online stuff.
Seems they have some QC issue
Seems they have some QC issues. That isn't go to be good for imaging, or anything really
The area that is affected by these discrepancies is the lower mids just at crossover, where you want good impedance behavior. Thats sort of the reason why FF.is used, but I suspect they got cheap on the FF with the problem one that has the higher impedance peak. You'll notice it on vocals or piano, especially when its played louder.
It also looks like they skimped on the front faceplate thickness and the back cup is a bit resonant.
It also looks like they skimped on the front faceplate thickness and the back cup is a bit resonant.