[Ricci]

Scott,

The proposed IB driver is interesting, but I would like to know if it would be possible to produce a 21" driver with enough BL to make it suitable for small sealed boxes of 6-8cu ft, so that it could be used in a 24 or 25" cube, with a long stroke linear motor, high power handling and a decently well controlled inductance probably through the use of shorting rings in the motor, for less than $1000? $700 or $800 ea would be awesome. I'm hoping that the high powered car audio version will end up close to this and not purely an all out SPL driver.

Could something like this or at least that models like this fictional set of parameters be done for that kind of price, or at all? :scratch:2 of these each in a sealed 24" cube EQ'd and powered off of a big QSC power amp like a PL6.0 would be absolutely killer for home audio/ HT.

RE 4.10
MMS 630 g
CMS 108 um/N
BL 27 t/m
FS 19.3hz
SD 1680cm
QES 0.430
QMS 5.80
QTS 0.400
VAS 432.4 L
LE 1.92 mh
XMAX 35mm
Xmech 42mm
PE 2000w
SPL 90.6 db

 

[Fi Audio]

Definitely doable. I would have to base it off a current motor design as I know that there would be a very limited market for the beast. But doing some quick calcs and FEA, I know its feasible without too much trouble.

thanks,
Scott

 

[Ricci]

Really...Interesting. Perhaps something involving that 4" vc based motor you guys are working on mated to the 22" frame being developed could make it happen?:whistling:. It surely would not be a high volume seller but depending on what it ends up costing it may not do too bad. I can think of quite a few people who'd be interested. I know that I'd buy a pair.

 

[Fi Audio]

Current 22" basket is only set up for 8" spiders as thats the vast majority of what we use.
If there seems to be enough interest I might pop out a limited production driver based off of CNCd baskets. Ive got a cool nested design that doesnt waste much material off of a sheet. Vs tooling another 22", Ill pass for now

 

[Ricci]

Hmmm. Wasn't aware that the 22" for the IB3 was 8" spider limited. It would be nice to have a set of 10's on there and that's pretty much a requirement with a larger than 3" vc like the 4" based motor. I suppose you could use a 3" vc on it but that just seems a bit out of place on a 21" driver that's gonna need a lot of thermal dissipation and excursion. :scratchhead: Wouldn't CNCing a limited production run 21" basket be hella:spend:?

What would we be looking at for the cone and surround off the top of your head? Heavy paper with foam?

I'm assuming from your comments that tooling up the 22" IB frame has NOT been smooth sailing?:R

 

[Fi Audio]

Its not that it hasnt been smooth sailing. We had an issue with the first sample being to thin at a few points and thats getting fixed. Other than that its been fine. But its the cost of things for something VERY limited in production. CNCing a basket isnt much of an issue if we have down time on one of the machines. Best to keep them cutting all the time. Yes, cost goes up as its being cut from sheet, but the design I have nests everything inside the mounting ring so there is minimal waste. For a driver that we might sell 50 of it makes more sense doing that than trying to eat $40k for the basket tooling for 50 drivers

 

[Ricci]

Ah. I follow now. I wasn't taking into account that you'd be machineing it yourselves in-house.

$40K is a chunk of cash. That's a lot of 22" IB3's to sell.

 

[onebadmonte]

Its not that it hasnt been smooth sailing. We had an issue with the first sample being to thin at a few points and thats getting fixed. Other than that its been fine. But its the cost of things for something VERY limited in production. CNCing a basket isnt much of an issue if we have down time on one of the machines. Best to keep them cutting all the time. Yes, cost goes up as its being cut from sheet, but the design I have nests everything inside the mounting ring so there is minimal waste. For a driver that we might sell 50 of it makes more sense doing that than trying to eat $40k for the basket tooling for 50 drivers

I'm sorry for getting off topic. This is the first I've heard of a basket made out of a sheet. Are you saying all the pieces are cut then welded up to make a basket? If so this sounds pretty cool. Is there any way you could post a pic of one of these baskets? Thanks, and umm, carry on.

 

[Fi Audio]

onebadmonte... By "sheet", I mean 1/2" 6061 aluminum sheet, not 16 gage... that would be a TIG nightmare to do With the 1/2" I can machine out the mounting flange, and then nest the legs, spider ring, and mounting ring all inside the mounting flange inner cut out. With 1/2" material I probably wouldnt strap a 100 lb motor to it, but for 90% of what I would want to do for one offs or most HT applications, its plenty strong. Normally bolted together vs TIG'd.

Thanks,
Scott

 

[Ricci]

As was posted in the 22" IB3 thread a counter coil would be nice or perhaps a split coil design with the vc's wired in opposite directions to combat inductance? This would probably add a lot of cost though right?

 

[anidabi]

Definitely doable. I would have to base it off a current motor design as I know that there would be a very limited market for the beast. But doing some quick calcs and FEA, I know its feasible without too much trouble.

thanks,
Scott

If it's doable and not that much of science fiction, then do it! I will buy one, or two. :R Riccis dream come true driver seems pretty good at least from modeling point of view. Models great in small subs and with only 150l enclosure you can use it's full potential with 3600w, which would be perfect here in europe. In 200l enclosure it would need only little over 2000w, so EP2500 owners would be happy.

But while we are in business designin our drivers in forums, here are my design parameters:
RE 3.0
MMS 650 g
CMS 100 um/N
BL 28 t/m
FS 19.74hz
SD 1800cm
QES 0.309
QMS 13.00
QTS 0.301
VAS 456.61 L
LE 1.92 mh
XMAX 35mm
Xmech 42mm
PE 2000w ??
SPL 92.6 db


Mr. Fi audio, isn't 8" spider a little bit too small for that size of a driver? It seems quite small for todays standard, especially after sicko dreaming and it's 14" spider, 8" spider sounds ridiculously small. Not that I know anything about the reality how it works and all. Also 3" VC sounds small for that size of a driver and it's power usage. Maybe you can educate me a little bit? What big Vc vs. small Vc means in reality(other than the ability to take more power and dissipate heat quicker) and small spider vs. big spider? :dunno:

 

[Mike P.]

With the new Fi built SMD series (built for Ascendant Audio) being introduced next month in 15 and 18 inch, it will be interesting to see the price and specs on the "rumored" 21 inch monster. I'd be curious to see how it models for HT, as it is, without any modifications.

 

[Ricci]

With the new Fi built SMD series (built for Ascendant Audio) being introduced next month in 15 and 18 inch, it will be interesting to see the price and specs on the "rumored" 21 inch monster. I'd be curious to see how it models for HT, as it is, without any modifications.

Exactly what I was thinking Mike. After you mentioned it to me I got to thinking that I should try to put in a word for us HT guys. :R. It's possible that if the car audio version gets produced it may be close enough that a few tweaks could be made. I just worry about the LE and whether it will have a really tight multiple spider suspension set-up for SPL primarily. It should already have massive power handling, xmax and high BL.

 

[Fi Audio]

Since Nick posted this one on the car audio forums after leaving CES, I might as well pop it on here as well

While not exactly the most useful basket for some monster HT or SPL applications, it was designed to round out the 12 spoke family. I used the 8" spider so that we have series uniformity/parts consolidation. Im not a fan of using 20 different spiders, coil sizes, and motors for the same "series".
We will have the revised 8" basket soon too. I have never been happy with the open tooling available for the 8" 12 spoke and recently redesigned things a little to accept a slightly larger spider and have better overall geometry.

If there is enough HT interest, and I do seem to be getting more and more emails about it, I am not opposed to doing some very HT specific drivers. When things settle down a little more and I clear up some of the new things from CES, I will spend a little time seeing what can be tweaked and what people feel they would want from a driver series or two and see what we can come up with.

Not too much of a "word" needs to be put in for the HT guys. It has been a driving force of mine for many years. I would much rather do HT OEM work than car audio oriented. It greatly reduces any failures designing for completed HT applications. While DIY HT is a little more akin to car audio(sorry, no disrespect ) as there are significantly more user controlled variables than for completed products or systems, it has 20X less the issues that car audio user have.

Thanks,
Scott

 

[onebadmonte]

:yikes: Dare I say Avalanche recone.:hide: Regardless, very impressive. May I be the first to say congrats. Cant wait to see your patented 6 spoke version (TC Sounds).

 

[Mike P.]

Great info, Scott! Thanks for posting!

 

[Ricci]

Awesome stuff Scott. That black 22" frame does look menacing. There are some real boneheads in car audio as there are in DIY HT too, but I believe that the percentage is MUCH higher among the car audio consumers. Some of the posts on the car audio forums are downright painful to read.:sad2:

 

[Fi Audio]

Dont think an Avalanche recone would work... well it would "work" but not be useful except for an IB application. Simply too much moving mass for that motor to support with a normal Qts. The 18" was pushing things when I designed it for Ascendant. We had to use a different cone that was a little thinner and a softer surround to get things to work out. A 22" would simply over work the little coil and motor for anything practical.

There definitely is a skewed ratio of "ignorance" in the car audio market. But I cant complain too much as it simply forces us to go overkill with some things. We ship them out and dont ever want them back... easiest way to do that is to educate and overbuild.

Thanks,
Scott

 

[buddhaears]

Hey there Scott,the work you're doing to bring this driver to life really earns my respect. I'll definitely buy 2. I've been looking at your IB18's for my next subbass(>40hz) project; and (slowly) working with a couple manufacturers in China for a 21" for an open baffle prototype I'm developing as our flagship fullrange speaker. The specs I need are pretty specific as you can imagine ( Pyle PDW21250 not the ticket),and your 22" could definitely do it. I hope to see more from you on the development, can't wait!
Happy 2009!!:jump:

 

[kryptonitewhite]

Scott,

The proposed IB driver is interesting, but I would like to know if it would be possible to produce a 21" driver with enough BL to make it suitable for small sealed boxes of 6-8cu ft, so that it could be used in a 24 or 25" cube, with a long stroke linear motor, high power handling and a decently well controlled inductance probably through the use of shorting rings in the motor, for less than $1000? $700 or $800 ea would be awesome. I'm hoping that the high powered car audio version will end up close to this and not purely an all out SPL driver.

Could something like this or at least that models like this fictional set of parameters be done for that kind of price, or at all? :scratch:2 of these each in a sealed 24" cube EQ'd and powered off of a big QSC power amp like a PL6.0 would be absolutely killer for home audio/ HT.

RE 4.10
MMS 630 g
CMS 108 um/N
BL 27 t/m
FS 19.3hz
SD 1680cm
QES 0.430
QMS 5.80
QTS 0.400
VAS 432.4 L
LE 1.92 mh
XMAX 35mm
Xmech 42mm
PE 2000w
SPL 90.6 db

I'll take one