would that resonance not be beyond the range the driver plays in . javad seems quite enthusiastic about the atc
jccart: if Fc is ~3kHz LR2 then there would be ~10dB suppression. But ATC itself chooses higher Fc ~3500Hz. I just mentioned that to see if this is in nature similar to what profiguy mentioned about Volt middomes.
OK then I guess it would be interesting to see how suppressed the resonance would need to be to be inaudible . my understanding is that all domes or cones have some kind of breakup . do atc cross at lr2 or higher ? I'm not saying they're the best thing ever just interested
At this point, you don’t need the 1.25” of tweeter dome….keep the radiation pattern wide as far as it goes……19mm is the best sized cherry for this flavor of sundae.
That’s a strange polar pattern…..the frequency of the petal pattern isn’t specified but at only 30 degrees +/- there’s a 10db suckout. Could be from the really deep horn loading or the phase shield they use. Either way, that’s an odd ball tweeter to say the least.
https://sbacoustics.com/product/sb19st-c000-4/
https://sbacoustics.com/product/sb19st-c000-4/
This SB19ST is indeed a nice tweeter, with excellent dispersion characteristics :
But according to its specs, a possible problem lies here for my 4-ways project, IMHO :
since the SS D7608-900010 3" dome midrange is the least efficient of all at 92dB/w/m, the 12BR70 being at 93dB/w/m and the 8M60N at 95dB/w/m...
T
Last edited:
... a piece of cake , right 🙂
... if only of few things woulda been better implemented! (Kapton former etc)
... if Rick Beato woulda ever confess he gets wet eyes , every time a Zappa guitar solo is coming along his ears :
... if only of few things woulda been better implemented! (Kapton former etc)
... if Rick Beato woulda ever confess he gets wet eyes , every time a Zappa guitar solo is coming along his ears :
Love this “rant” and great points made maybe the key is to either avoid bad recordings or have two pairs of speakers next to each other and switch back and forth as needed
I have used these and my opinion is that while they are very good at transients they also are too bright in the upper mid on some recordings
I use an lpad to tone them down a bit
The aluminum dome has a breakup about 10 kHz so need to cross these over pretty low to a capable tweeter
So here is a more general thought on the topic of dome mids. I have been a dome guy since the 70s - used the Phillips 2"ers back then (that were also used in a KLH model), and used these with the Peerless 1" fabric domed tweeter (that were used by Polk and others). I liked them based on the dispersion and openness (soundstage) of the effect. Also, AR really pioneered the use of domes for both tweeters and mids with the model 3a. I figured those guys were pretty smart and I Iived in Cambridge, MA, the epicenter for AR, KLH, Bose, Advent et al. But I also rack-mounted the domes (as they were sealed) inspired by Dahlquist (although it had several drivers rack mounted above the woofer). This approach again sounded airy and open, plus diffraction / baffle effects were getting increased attention at the time in the audio mags.
I retired the old speakers many years later (pic included). The 2" Phillips dome mid crossed at 500 Hz (12 dB slope) to the 12" Phillips woofer (air suspension design) but this was also a big "gap" in driver size and demanded the woofer venture well into the vocal range. A couple years ago I decided to go with Olsen's research and build spherical speakers, two spheres pole mounted, one using a 5-1/4" Dynavox midwoofer and one an 1-1/4" Dayton fabric dome tweeter. The drivers certainly aren't the priciest by good performance for the money. Pic also attached. The midwoofer gets down to 100 Hz well, but need a sub for the lower bass (shown). (And for those who quickly think about standing waves in a sphere, the pole running through the lower sphere prevents that along with the damping materials used).
I like domes as I feel they complement a sphere with the hemispherical shape and dispersion. And they have quick transient response with a good ratio of the motor / coil to the mass of the piston - and are very pistonic. But I do agree with earlier posts that domes are less forgiving with poorer recordings.
So how does the Dynavox midwoofer relate to dome mids in this thread? It's really a rare bird, as it has a 3" VC with a domed configuration to the driver (its poly material), so it's really a 3" domed mid with an added surround that makes it into a midwoofer capable of getting down to 100 Hz before needing to be crossed to a sub. The Xmax is about 2.5 which still gives it quick transient response. I cross it at 100 Hz to the sub and 2,000 Hz to the 1 1/4" dome Dayton tweeter (both slopes 12 dB). This avoids the cone breakup that does occur in the Dynavox above 5 - 6 kHz. The tweeter has high power handling and can easily get you to 2,000 Hz, with a surface area about 30% more than a 1" dome, but also gets out well beyond 18 kHz.
Why do this? The key consideration was to have one driver cover all of the vocal range, rather than split that range with the usual 400, 500 or 600 Hz crossover point you need with a typical dome mid, whether a 3" or 2". So this yields the advantage of a 3" dome mid (because it has that) with a bit larger surround that avoids a crossover point in the vocals. The vocals on these are very smooth - even "brassy" sounding singers don't sound brassy - and difficult orchestral instruments like French horns, which need solid but smooth midrange performance, are reproduced exceptionally well. The vocals IMO really make or break a speaker across the freq. range that contains most of the content we hear (setting aside the lower bass).
So is this a 3" dome? Yes I think so, but with added benefit. There are very few drivers with 3" coils and domed configurations AND midwoofer range like this (Dynaudio of course but a lot more $). So my approach to all of this.
I retired the old speakers many years later (pic included). The 2" Phillips dome mid crossed at 500 Hz (12 dB slope) to the 12" Phillips woofer (air suspension design) but this was also a big "gap" in driver size and demanded the woofer venture well into the vocal range. A couple years ago I decided to go with Olsen's research and build spherical speakers, two spheres pole mounted, one using a 5-1/4" Dynavox midwoofer and one an 1-1/4" Dayton fabric dome tweeter. The drivers certainly aren't the priciest by good performance for the money. Pic also attached. The midwoofer gets down to 100 Hz well, but need a sub for the lower bass (shown). (And for those who quickly think about standing waves in a sphere, the pole running through the lower sphere prevents that along with the damping materials used).
I like domes as I feel they complement a sphere with the hemispherical shape and dispersion. And they have quick transient response with a good ratio of the motor / coil to the mass of the piston - and are very pistonic. But I do agree with earlier posts that domes are less forgiving with poorer recordings.
So how does the Dynavox midwoofer relate to dome mids in this thread? It's really a rare bird, as it has a 3" VC with a domed configuration to the driver (its poly material), so it's really a 3" domed mid with an added surround that makes it into a midwoofer capable of getting down to 100 Hz before needing to be crossed to a sub. The Xmax is about 2.5 which still gives it quick transient response. I cross it at 100 Hz to the sub and 2,000 Hz to the 1 1/4" dome Dayton tweeter (both slopes 12 dB). This avoids the cone breakup that does occur in the Dynavox above 5 - 6 kHz. The tweeter has high power handling and can easily get you to 2,000 Hz, with a surface area about 30% more than a 1" dome, but also gets out well beyond 18 kHz.
Why do this? The key consideration was to have one driver cover all of the vocal range, rather than split that range with the usual 400, 500 or 600 Hz crossover point you need with a typical dome mid, whether a 3" or 2". So this yields the advantage of a 3" dome mid (because it has that) with a bit larger surround that avoids a crossover point in the vocals. The vocals on these are very smooth - even "brassy" sounding singers don't sound brassy - and difficult orchestral instruments like French horns, which need solid but smooth midrange performance, are reproduced exceptionally well. The vocals IMO really make or break a speaker across the freq. range that contains most of the content we hear (setting aside the lower bass).
So is this a 3" dome? Yes I think so, but with added benefit. There are very few drivers with 3" coils and domed configurations AND midwoofer range like this (Dynaudio of course but a lot more $). So my approach to all of this.
Attachments
Many of those guys without meas mic fall in the Olson trap thinking a sphere is the optimum cab shape .. no it's not! (dull academons will fail this test)
Olson used an unusual large sphere (closer to a infinite plane) and a very small driver size (with virtual no flange) , so the "diffractiviness" is much less than real world combinations which allows you get much higher SPL levels by holding cab volume accetable low! (also - a 1000mm sphere will ring mechanically like hell)
And in the photo above showing the room there are tons of reflections!
So you might have solved one problem and created a similar one too!
The large vertical distance is an additional one .... then , between both spheres , strong nearfield reflections came into play shifting your stereo experience into an absurdity!
To get the full picture you need several different meas signals!
happy techdiving for the next 100 years and becoming an expert on audio basix 🙂
Olson used an unusual large sphere (closer to a infinite plane) and a very small driver size (with virtual no flange) , so the "diffractiviness" is much less than real world combinations which allows you get much higher SPL levels by holding cab volume accetable low! (also - a 1000mm sphere will ring mechanically like hell)
And in the photo above showing the room there are tons of reflections!
So you might have solved one problem and created a similar one too!
The large vertical distance is an additional one .... then , between both spheres , strong nearfield reflections came into play shifting your stereo experience into an absurdity!
To get the full picture you need several different meas signals!
happy techdiving for the next 100 years and becoming an expert on audio basix 🙂
Spheres avoid baffle step points that occur with flatter panels
Spheres don’t resonate as they are the strongest geometric shape they would have to actually pulse in and out to do that
The photo isn’t showing the actual listening room
The driver distance isnt audible at normal listening distance
The imaging is very very good
There are tons of speakers that measure well but also many if these sound very different
Build a pair and listen with your ears and not a chart
Spheres don’t resonate as they are the strongest geometric shape they would have to actually pulse in and out to do that
The photo isn’t showing the actual listening room
The driver distance isnt audible at normal listening distance
The imaging is very very good
There are tons of speakers that measure well but also many if these sound very different
Build a pair and listen with your ears and not a chart
Someone needs to go through this thread and extract all the make and model of domes mentioned to make a reference thread 🙂
I was also interested in this driver . hoe did you find the quality seems to be a massive bargain if the quality control is good . this is essentially a clone if the dynaudio 15w75 correct ?
The forum table is horrible, so here's a picture of midrange domes one can buy 😎
NLA mentioned in the thread are Beyma MC115, Dynaudio D52AF D54 D76AF, Peerless OEM, Philips AD0210/SQ4, Seas H304, Usher 9845C, Vifa D75MX, Yamaha NS1000.
NLA mentioned in the thread are Beyma MC115, Dynaudio D52AF D54 D76AF, Peerless OEM, Philips AD0210/SQ4, Seas H304, Usher 9845C, Vifa D75MX, Yamaha NS1000.
The Vifa D75MX is identical to the SS D7608.
The various domes made in the far east tend to change from batch to batch. This makes their data unreliable. Morel drivers tend to be very consistent. SB has changed the running specs of their MD60N but hasn't updated published FR curve.
The various domes made in the far east tend to change from batch to batch. This makes their data unreliable. Morel drivers tend to be very consistent. SB has changed the running specs of their MD60N but hasn't updated published FR curve.
out of that I like the tangband followed by the morels then maybe the caire and the hivi are worth a punt at 50quid odd
Javad Shadzi is in the middle of documenting a 3way with a Ciare Dome (plus Claire woofer and tweeter) on the Facebook DIY Loudspeaker Project Pad Calle the Sea-airs.
https://www.facebook.com/groups/DIYLoudspeakerProjecPad/permalink/2153887248300434/
https://www.facebook.com/groups/DIYLoudspeakerProjecPad/permalink/2153887248300434/