Don't know whether this moves you toward the cone response as shown in Olsen's charts on the previous page?
As for speaker size and type, are you trying to do a "full range"...?
As for speaker size and type, are you trying to do a "full range"...?
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As planet10 was writing, B&W has done further research ending up with a teardrop shape that is better than spherical.
I bought two 28 cm Matte and two Gronsaker, the former to be used in front where the speaker is, the latter on the back to give the teardrop shape.
I’m open to every suggestion, but the idea is to have a full-range speaker, indeed.
I bought two 28 cm Matte and two Gronsaker, the former to be used in front where the speaker is, the latter on the back to give the teardrop shape.
I’m open to every suggestion, but the idea is to have a full-range speaker, indeed.
Olsen's chart shows the sphere is almost ideal, hard to get the freq curve much smoother IMO. The tear drop may be thought to have advantages internally with standing waves, but these can be addressed using a small and offset insertion of dense damping material within the sphere, and this again IMO is far easier to do than try and construct a tear drop that attempts to match what B&W does out of DIY materials. The B&W shape is precisely manufactured (you can do this with molds for example). Are you looking to glue together one Matte and one Gronsaker (which is essentially a half sphere with a base)? Then, where would you look to cut the hole the mount the driver?
As for full range, my opinion has always been there really is no such thing if you want to cover good bass well below 100Hz through to really crisp highs. Something gets sacrificed. You can focus on mid bass to the high end but still would need a sub to complement IMO. So you can attempt to DIY the high tech tear drop shape while putting in a single driver.
Attached is one example of a DIY that uses the large bowl for a single driver mounted plus a small tweeter on top (not hard to do) and then a simple base. I would use a decent say 6" - 7" woofer and 1" tweeter with small face plate and cross over where appropriate based on the drivers selected. There's plenty of room to stick the crossover board in the sphere and the terminals on the back lower down to the base. And put in place inside an offset object to break up any standing wave issue. Most smaller woofers need a 1/3 cu ft or less volume (sealed) or less with a port, and the sphere gives you about 1/3 cu ft.
This can get you down to maybe 80Hz pretty well, and if you want deeper base, add a sub to the system. You can just buy one as at these low frequencies, the sphere shape no longer really matters with the very long wavelengths.
In order for a sphere to vibrate with any resonances, it needs to pulsate which is unlikely as it is simply the strongest enclosure, even more so than an ellipsoid. I use a 3-part damping approach with acoustic paint (essentially latex with cement mixed in to make the wood as much like cement board as possible), then dense carpet underlay glued in and finally fiberglass stuffing. I put in my 4-sphere design a 6.5" Skar sub (down-firing) into the bottom sphere and played a lot of deeper base stuff (incl. prominent base drums and cannons in certain good recordings) and have not been able to hear any vibrations caused by the enclosure.
As for full range, my opinion has always been there really is no such thing if you want to cover good bass well below 100Hz through to really crisp highs. Something gets sacrificed. You can focus on mid bass to the high end but still would need a sub to complement IMO. So you can attempt to DIY the high tech tear drop shape while putting in a single driver.
Attached is one example of a DIY that uses the large bowl for a single driver mounted plus a small tweeter on top (not hard to do) and then a simple base. I would use a decent say 6" - 7" woofer and 1" tweeter with small face plate and cross over where appropriate based on the drivers selected. There's plenty of room to stick the crossover board in the sphere and the terminals on the back lower down to the base. And put in place inside an offset object to break up any standing wave issue. Most smaller woofers need a 1/3 cu ft or less volume (sealed) or less with a port, and the sphere gives you about 1/3 cu ft.
This can get you down to maybe 80Hz pretty well, and if you want deeper base, add a sub to the system. You can just buy one as at these low frequencies, the sphere shape no longer really matters with the very long wavelengths.
In order for a sphere to vibrate with any resonances, it needs to pulsate which is unlikely as it is simply the strongest enclosure, even more so than an ellipsoid. I use a 3-part damping approach with acoustic paint (essentially latex with cement mixed in to make the wood as much like cement board as possible), then dense carpet underlay glued in and finally fiberglass stuffing. I put in my 4-sphere design a 6.5" Skar sub (down-firing) into the bottom sphere and played a lot of deeper base stuff (incl. prominent base drums and cannons in certain good recordings) and have not been able to hear any vibrations caused by the enclosure.
Attachments
I would think about adding a styrofoam tail to the bottom of the Gronsaker. but if the 2 mate up (you do need a connecter ring (where i put the vents) as these vbowls are not fully hemispherical.
Do note that Blanda miniOnken for the A5.2/3 started out as a larger one for the CHR70. ie the basis of a 28cm one is already in place.
dave
Olson’s work was done in the ‘40s/50s. B&Ws research was based on Olson’s early work. Better tools allowed for deeper research (and they weren’t starting from scratch). Sphere is good (but has bad internal resonance, teardrop is subtly better on the outside (as you state, Sphere is pretty good) and way better on the inside.
And by Toole, also with multiway loudspeakers. Not because of the loudspeaker, but because of the room.
The best FR designs are hitting 9.5 octaves. Ultimate loudness will not suiy head-bangers.
Most peopel have not heard a really good FR design (i can probably say the same for multi-ways). Every loudspeaker is a huge set of compromises. One has to choose the best set for the end listener’s ears.
dave
Right, one only need look at non jet powered land speed record vehicle shapes that have come close/'punched' through the SoS to get a 'feel' for what works best overall.
I would like to keep the wood visible (I like the two colours of the two woods together), so probably a lathered leg of a furniture would better fit the look I have in mind.
I remember you highly prefer 7ms compared to CHR70. Will it fit the two?
What are the performances you expect from it?
Thanks
Roberto
I did up until me and a few others experienced the late Babb Lorelei, a true 20 -20 kHz coaxial single driver that needed no EQ. Basically it was a 4th order BP (sealed with no repairability 🙁) where the low pass filter was a built-in screen phase plug, so a very wide/flat polar response (IMHO too much for HIFI) and had a 1" Xmax roller bearing shaft in lieu of a spider, so typical suspension distortion was nil, though the supper lossy surround could make some interesting crinkly noises (it looked like wrinkled crepe paper IIRC) at high excursion up close. No power rating as such, though Alan (Babb) said he'd tested his own HT? setup at 400 W with no issues and my (turned out long term, gifted) pair withstood ~250 W.
Sadly, there was some sort of falling out among the principles and Babb speakers was sold to DC Gold, which chose not to pursue it and while I saved much of what docs were either published or were sent me in confidence is now locked in two damaged HDs thanks to a computer short/fire while doing a BU.
Clueless about such stuff, just at the time discussed with some computer geeks that recommended a few shops that would try to recover at 'x' $$/hr with no guarantee, but none mentioned anything like this and without digging them out of wherever I stored them (long time ago now, so too obsolete to swap?) all I can remember is that one or both of their wiring/connections were all burned up.
Sounds like it's worth a shot swapping the boards, if you can find the exact same HD model (even with a bad disk).
There are lots of obsolete computer parts around. Even clubs, museums, etc, so check around.
You only need one good board, which could be used on both. Just be sure it's the exact same model and version of HD.
There are lots of obsolete computer parts around. Even clubs, museums, etc, so check around.
You only need one good board, which could be used on both. Just be sure it's the exact same model and version of HD.
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Some interesting opines on FR drivers vs. multi-way on audiosciencereview.com:I did up until me and a few others experienced the late Babb Lorelei, a true 20 -20 kHz coaxial single driver that needed no EQ. Basically it was a 4th order BP (sealed with no repairability 🙁) where the low pass filter was a built-in screen phase plug, so a very wide/flat polar response (IMHO too much for HIFI) and had a 1" Xmax roller bearing shaft in lieu of a spider, so typical suspension distortion was nil, though the supper lossy surround could make some interesting crinkly noises (it looked like wrinkled crepe paper IIRC) at high excursion up close. No power rating as such, though Alan (Babb) said he'd tested his own HT? setup at 400 W with no issues and my (turned out long term, gifted) pair withstood ~250 W.
Sadly, there was some sort of falling out among the principles and Babb speakers was sold to DC Gold, which chose not to pursue it and while I saved much of what docs were either published or were sent me in confidence is now locked in two damaged HDs thanks to a computer short/fire while doing a BU.
https://www.audiosciencereview.com/...ifferent-compared-to-2-way-etc-speakers.6967/
For sure much has been written about FRs over the years. The key point I see from many of these posts is that for certain limited forms of music, such as a vocal and acoustic piece with just a very few instruments, FR works ok. But say for an orchestral piece, not going to do justice to it. The key IMO is to A-B whatever good FR speaker you like (single driver in an enclosure), against a good 2-way with smaller woofer, plus a sub, for low bass. Successful crossovers for 2-ways certainly have been done over the years, and a separate sub requires the typical high-pass/low-pass at somewhere around 80-100 Hz.
Hi,
with those Blanda speakers with EG 7MS, what can be a suggested speaker and configuration of the cabinet to cover the lowest audible range?
Thanks
with those Blanda speakers with EG 7MS, what can be a suggested speaker and configuration of the cabinet to cover the lowest audible range?
Thanks
2 blanda bowls wil get you to maximum A7ms extension in a miniOnken, a bit less with Blands + Gronsaker is a bit less volume.
Based on sims, the first would have F6~mid 40s, F10~near 40, and you would XO at a woofer at F3 ~ low-mid 50s.
dave
Based on sims, the first would have F6~mid 40s, F10~near 40, and you would XO at a woofer at F3 ~ low-mid 50s.
dave