A room with reasonable sound damping and space is enough to get great sound from a pair of great speakers.
Good speakers will sound good in an alright room.
I see so many pictures of audiophile rooms with hardwoods and rear concrete or brick walls with few carpets and leather furniture. This is not the way to enjoy expensive speakers. Not much would be required in those rooms to get a better sound but owners prefer to change speakers every year, never point at the hardwood floors, bare concrete
Good speakers will sound good in an alright room.
I see so many pictures of audiophile rooms with hardwoods and rear concrete or brick walls with few carpets and leather furniture. This is not the way to enjoy expensive speakers. Not much would be required in those rooms to get a better sound but owners prefer to change speakers every year, never point at the hardwood floors, bare concrete
Well .... would you point at these details if you were their dealer ?
Regards
Charles
P.S.: A serious dealer who wants to make his customers happy would indeed do that, but one that is only interested in selling expensive stuff wouldn't.
Indeed, those poor customers are like a cat chasing his tail.
Likely not published but take this example of the JBL 1500AL series woofer.
The first 1500AL had a cone made of felt and aramid fiber and it was thought that it was a bit dull compared to felt and glass fiber. The next gen 1501AL used glass.
The 1501-1 got a surround change and a drop in FS.
If that could have been addressed with a network tweak (EQ) I bet they would have just done that.
Barry.
Nice, could you say where we can buy them ?
PS: i've modelized them and asked for a quotation to serious 3D printers professionals, it costs 600$ for each WG.
I understand that you consider speaker driver (non linear) distortion reduction as practically a "solved problem".
Do you think that further reduction of break-up and decay in speaker cones is also unnecessary?
I propose a constrained layer damped cone, which should have "Faster decay", in this case of the cone resonances rather than horn modes.
I know you have developed constrained layer damped enclosures, presumably you felt it a worthwhile improvement, I am curious to know your opinion of its value in the driver itself.
You are welcome to comment in my "Metal-Paper-Metal Cone" thread if you think it OT in this one.
Best wishes
David
No, I haven't built one and know of no driver that is readily available.
The fact that it is so uncommon is a surprise because the idea seems obvious.
Hence my questions before I spend the time.
Best wishes
David
What about this unit? Has a bit in common with the famous KEF B139?
Low THD Tang Band RBM drivers?
Fair to say that maybe THD is not as big an issue with sub speakers as other issues.
BTW, us electrostatic speaker enthusiasts never cease raving about the clarity of our speakers. Maybe there is a substantially better distortion result with ESLs that is readily admired as compared to minor distortion tweaks between otherwise comparable cone drivers that is too small to admire?
B.
I have seen some ELAC drivers that use this method. But I tend to shy away from this method. But metal cones have two design flavors, one strong breakup mode and distributed breakup modes. The former is more commonly seen, the later mostly evolved from Jordan technology which uses slightly softer aluminum cones with specifically tuned anodizing. Generally tuning these are not so simple. I am still trying to find a way that will provide improved performance for a 6.5 inch driver, but it is quite difficult to do so.
In theory this seems doable, but I bet that in practice it would prove to be difficult. "Paper" would not satisfy the needs of the internal bonding layer unless it was heavily impregnated with a damping compound. All of this adds considerable mass to the cone, which is never a great idea. I do highly doubt that any cone manufacturers would spend the time and money investment necessary to make this work as it would not be easy. Thermal bonding of two very thin layers of metal might work, but as to the practicality of such a scheme I am not the expert.
I had some Focal mids (purchased almost 20 years ago) that used a composite cone - a double skin to sandwich an inner layer. They used to call this filling "resin micro beads" (or something similar), now they call it a "foam" core - probably the same thing, just stated differently. Is that the kind of thing y'all mean?
The “W” composite sandwich cone | Focal | Listen Beyond
This 6.5" driver looks kinda similar to the model I once had, and the cone material looks like it hasn't changed.
6W4311B - Focal 6.5" Shielded "W" Cone Midbass Speakers
An Australian retailer sells some Focal drivers, and it looks like a W cone driver costs 50-100% more than the equivalent 'polyglass' driver.
My idea is to use the bond adhesive between the metal and the paper as the constrained layer, the paper itself would be essentially a core.
Natural losses in the core would still be beneficial but no material would be added to the core.
This idea should not add mass, in fact the more efficient sandwich structure should allow a less massive cone.
Performance yachts, F1 race cars and aircraft use a lot of sandwich for precisely this reason.
The cone mass reduction is part of the attraction of the idea, like you I want an efficient cone driver, a natural fit with compression drivers I use.
Thanks for the reply, do you have any data on paper cone materials from your discussions with speaker manufacturers, or other sources?
Best wishes
David
"Resin micro beads" and "foam" are different terms, at least in the boat industry where I messed around.
Resin beads are probably hollow beads of plastic mixed with resin, it's not a performance core but it's a cheap and simple minor improvement.
Foam is plastic foam as a core, better but still not usually top end.
I am specifically interested in Al-paper-Al laminates because paper cones are not too expensive and already remarkably effective for such an apparently primitive material.
Reasonably well damped, reasonably stiff, not too heavy.
An improved sandwich paper looks pretty attractive, better damped, stiffer, even less heavy.
Paper cones are readily available to experiment, hopefully not too difficult to stick thin(ish) Al faces to one.
3m has some viscoelastic adhesives apparently aimed at the CLD and noise reduction market, so they seem exactly what we need.
Best wishes
David
options
1) Electrodeposit metal skins on a preformed nonmetallic substrate.
2) Bond metal foil to a 3d printed honeycomb structure, possibly carbon fiber.
Beryllium is the ideal metal due to its superior mechanical-acoustical properties, but it is extremely expensive and difficult to form.
N.B., The glue (resin) you use also adds mass as well.
For subwoofers, prefer to expend resources on extending motor excursion and servo control. See Power-Soft M-Force design for a good example.
Regards,
WHG
For applications above say 100 Hz., some possible options include:
1) Electrodeposit metal skins on a preformed nonmetallic substrate.
2) Bond metal foil to a 3d printed honeycomb structure, possibly carbon fiber.
Beryllium is the ideal metal due to its superior mechanical-acoustical properties, but it is extremely expensive and difficult to form.
N.B., The glue (resin) you use also adds mass as well.
For subwoofers, prefer to expend resources on extending motor excursion and servo control. See Power-Soft M-Force design for a good example.
Regards,
WHG
No not really. I didn't get into cone design, except I know that paper still appears to be king, although binders tend to be variable.