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Discussion Starter · #1 ·
Like the thread title states. If Fi produced a small box 21" driver for less than $1000 hopefully $700 or so, would you be interested? I Have a thread going at HTS where I'm talking to Scott A. about the possibility of making it happen. They are already building a 22" IB driver, but it will not be useful for much other than that if I had to bet. I threw these rough parameters at him to see what he thought. He seems to think it's easily do able for under $1K. This would be a linear, high displacement, reasonable inductance, high power handling, high BL,small box 21". The target goal in my mind would be 2-3KW power handling in a sealed 6-7cu ft enclosure (24" cube), without exceeding the driver's limits anywhere in the bass range. It's looking like some possibilities would be a CNC'd custom frame, 4"vc based motor with shorting rings, 10" spiders.

http://www.hometheatershack.com/foru...d-produce.html



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



Thoughts?
 

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I think the key to selling drivers over $300-400 is testing results. If they could design and build a protype that would could be tested by a reputable source, like Illka or AV Talk.

Then I think there would be a market for something in the over $500 range, especially with the impressive xmax, power handling, displacement potential, etc.

IMO it is difficult to judge based on proposed parameters. But, slap one in a box and feed a couple of kilowatts and post the results...if favorable, lookout.
 

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Quote:
Originally Posted by Ricci /forum/post/15486731


Like the thread title states. If Fi produced a small box 21" driver for less than $1000 hopefully $700 or so, would you be interested? I Have a thread going at HTS where I'm talking to Scott A. about the possibility of making it happen. They are already building a 22" IB driver, but it will not be useful for much other than that if I had to bet. I threw these rough parameters at him to see what he thought. He seems to think it's easily do able for under $1K. This would be a linear, high displacement, reasonable inductance, high power handling, high BL,small box 21". The target goal in my mind would be 2-3KW power handling in a sealed 6-7cu ft enclosure (24" cube), without exceeding the driver's limits anywhere in the bass range. It's looking like some possibilities would be a CNC'd custom frame, 4"vc based motor with shorting rings, 10" spiders.

http://www.hometheatershack.com/foru...d-produce.html



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



Thoughts?


Well, I haven't had a chance to play with those specs you provided, just about to leave the office now. Quick answer, of course!!! You know me, Ricci.



I'd be down for something like a 21 inch version of the Maelstrom-X, personally. I highlighted the "purpose" part of this intended subwoofer. I like.
 

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I dont have any modeling software on my work pc so I cant model it myself. How does it do in a large ported enclosure? How big of an enclosure do you need to get it flat and where does it tune to? Everything I've heard about FI has been extremely positive. I'd be very interested in a two nice 2X" drivers.
 

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I would be more apt to buying 2, 18's for the same price as a single 21, but that's just me.
 

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Quote:
Originally Posted by Looneybomber /forum/post/15487065


I would be more apt to buying 2, 18's for the same price as a single 21, but that's just me.

My thoughts were along these lines... Would it outperform two Maelstrom-X's? Sounds like the driver cost will be roughly the same.
 

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xmax and xmech are too close - that is an extremely poor design.


i would never buy this woofer based on this alone.


make xmax 30 mm and xmech 60 mm and i'll think about it.
 

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Discussion Starter · #8 ·
The answer to all of the questions so far is I don't know or who does know. It doesn't exist. But apparently it could be made. I'm just fooling with #'s and trying to determine at what point would it be realistic to produce a high quality 21" for a HT type application.


Vas,

I'd of course like to see an xmax of over 40mm, xmech over 60mm so that it's nearly impossible to bottom and all you ever worry about is the thermal handling. I don't see 30 to 35mm xmax and 42mm xmech as bad at all. They are just ******** #'s that I thought wouldn't be too hard to attain. If you run the BS #'s in a 6 cu ft sealed box and dump 3KW into it it would never be in danger mechanically. The LMS drivers are 38mm and only 44mm xmech which is even closer and they bottom hard, Mal X is 33mm and about 42mm, Aura 1808 was 19mm and 38mm. It would be right in the thick of it with the way it is proposed.


The problem with trying to get a whole buttload of excursion clearance is that the motor starts getting crazy heavy and expensive as does the surround and spiders needed to control things, especially on a driver that big. It ends up costing way too much. That's what happened with the Sicko idea. It would've been an awesome piece but at probably $2500 per driver it's not going to happen.


The way I look at it you can design a driver that is "all out" in every respect and have it be $1800ea which never sells or you can make something comparable to a 21" Mal X that hopefully comes in significantly cheaper.


What if it could be produced for $600? $500?
 

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Quote:
Originally Posted by Ricci /forum/post/15489422


The answer to all of the questions so far is I don't know or who does know. It doesn't exist. But apparently it could be made. I'm just fooling with #'s and trying to determine at what point would it be realistic to produce a high quality 21" for a HT type application.


Vas,

I'd of course like to see an xmax of over 40mm, xmech over 60mm so that it's nearly impossible to bottom and all you ever worry about is the thermal handling. I don't see 30 to 35mm xmax and 42mm xmech as bad at all. They are just ******** #'s that I thought wouldn't be too hard to attain. If you run the BS #'s in a 6 cu ft sealed box and dump 3KW into it it would never be in danger mechanically. The LMS drivers are 38mm and only 44mm xmech which is even closer and they bottom hard, Mal X is 33mm and about 42mm, Aura 1808 was 19mm and 38mm. It would be right in the thick of it with the way it is proposed.


The problem with trying to get a whole buttload of excursion clearance is that the motor starts getting crazy heavy and expensive as does the surround and spiders needed to control things, especially on a driver that big. It ends up costing way too much. That's what happened with the Sicko idea. It would've been an awesome piece but at probably $2500 per driver it's not going to happen.


The way I look at it you can design a driver that is "all out" in every respect and have it be $1800ea which never sells or you can make something comparable to a 21" Mal X that hopefully comes in significantly cheaper.


What if it could be produced for $600? $500?

Some people would complain if you gave them $20 because now they have to put it in their pocket and its going to be a pain to break.



If this 21" was $500 I'd buy 4.
 

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Looks interesting, but any 21" woofer would have to be within 10% of the Maelstrom-X's Vd/$ position to draw any interest from me, and that's with a trick motor (XBL^2, split-opposed-coil, LMT, underhung NRT, etc.) and an Le/Re ratio that equals or betters the Mael-X's.


With a conventional long-coil overhung motor, it would have to be a considerably better value proposition than said Mael-X.


KH, DW, and so on really set the bar high with that one.
 

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Quote:
Originally Posted by Ricci /forum/post/15489422


The answer to all of the questions so far is I don't know or who does know. It doesn't exist. But apparently it could be made. I'm just fooling with #'s and trying to determine at what point would it be realistic to produce a high quality 21" for a HT type application.


Vas,

I'd of course like to see an xmax of over 40mm, xmech over 60mm so that it's nearly impossible to bottom and all you ever worry about is the thermal handling. I don't see 30 to 35mm xmax and 42mm xmech as bad at all. They are just ******** #'s that I thought wouldn't be too hard to attain. If you run the BS #'s in a 6 cu ft sealed box and dump 3KW into it it would never be in danger mechanically. The LMS drivers are 38mm and only 44mm xmech which is even closer and they bottom hard, Mal X is 33mm and about 42mm, Aura 1808 was 19mm and 38mm. It would be right in the thick of it with the way it is proposed.


The problem with trying to get a whole buttload of excursion clearance is that the motor starts getting crazy heavy and expensive as does the surround and spiders needed to control things, especially on a driver that big. It ends up costing way too much. That's what happened with the Sicko idea. It would've been an awesome piece but at probably $2500 per driver it's not going to happen.


The way I look at it you can design a driver that is "all out" in every respect and have it be $1800ea which never sells or you can make something comparable to a 21" Mal X that hopefully comes in significantly cheaper.


What if it could be produced for $600? $500?

are you trying to make me stop liking the LMS ?



if your numbers for LMS are correct then probably what happened is they simply recycled the suspension from their less linear drivers instead of giving the LMS the suspension it deserves.


also large xmax might have been an UNDESIRABLE side effect of linearity on the LMS motor. its quite possible that they couldn't have a 25 mm xmax and still keep the driver as linear within it.


they had to work with the geometry of the field their magnet was producing as well as with available suspension components - that doesn't mean the result should be used as a guideline for future development.


i like the numbers on Aura much better. and if you noticed the MMS on Aura is quite low despite the large xmech.


why do you want xmax in the 30mm plus range ? dance club and movie theater subwoofers have less than 10 mm xmax and they are the benchmark.


a good 21" subwoofer with just 20mm xmax would easily slaughter basically any driver on the market for bass ( as opposed to huffing and puffing ).


i think you need to slow down and think about what is the real reason for your obsession with xmax? don't make me go all freudian on you
 

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Quote:
Originally Posted by Ricci /forum/post/15489422


The answer to all of the questions so far is I don't know or who does know. It doesn't exist. But apparently it could be made. I'm just fooling with #'s and trying to determine at what point would it be realistic to produce a high quality 21" for a HT type application.


Vas,

I'd of course like to see an xmax of over 40mm, xmech over 60mm so that it's nearly impossible to bottom and all you ever worry about is the thermal handling. I don't see 30 to 35mm xmax and 42mm xmech as bad at all. They are just ******** #'s that I thought wouldn't be too hard to attain. If you run the BS #'s in a 6 cu ft sealed box and dump 3KW into it it would never be in danger mechanically. The LMS drivers are 38mm and only 44mm xmech which is even closer and they bottom hard, Mal X is 33mm and about 42mm, Aura 1808 was 19mm and 38mm. It would be right in the thick of it with the way it is proposed.


The problem with trying to get a whole buttload of excursion clearance is that the motor starts getting crazy heavy and expensive as does the surround and spiders needed to control things, especially on a driver that big. It ends up costing way too much. That's what happened with the Sicko idea. It would've been an awesome piece but at probably $2500 per driver it's not going to happen.


The way I look at it you can design a driver that is "all out" in every respect and have it be $1800ea which never sells or you can make something comparable to a 21" Mal X that hopefully comes in significantly cheaper.


What if it could be produced for $600? $500?

09 ultra's are up to 50 xmech (new motor... not out yet)
 

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I guess that it all depends on the SQ and measurements....


Quote:
Originally Posted by KyleLee /forum/post/15491056


09 ultra's are up to 50 xmech (new motor... not out yet)

That sounds extremely inviting, but I'm really concerned about cost as well as the entrance fee for the amp to drive it... If its going to cost $4K for the amp and $2K for the driver, I think were starting to get into diminishing returns here... And what size box are we talking if it was to be Sealed, or at least passive


On the minimum I need 2 drivers like an 18" LMS/Ultra to pressurize my room, which means things are really starting to stretch financially.
 

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Another vapor ware driver with many saying YES I WANT and few buying.


What will this one be called?



Sure a 21" driver,first they should answer calls or even emails,before I even think about spending.


Lets get real here. You offer a niche product,there is a market,it is a small market for the few. You better answer those few who have the money and will to spend on these products.
 

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$500 would be good, but $700 and above I would look at dual units of Mal-X....put it into 2 boxes and spread it out. Economy's still not that good man...even over here in the Far East.


I can't find the Mal-X on diycable, what happened? Supply issues?


Vas, for Home Theatre and doing 20Hz and below operation at triple digits dB + 15dB headroom at least, it'd better have good Xmax even for duals/quads even factoring in room gain. I'm surprised at some of the hardcore guys' systems in this DIY section.

And seriously those super hardcore guys would already have decided on a IB anyway, say your mentioned 22" Fi IB driver.
 

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Discussion Starter · #16 ·

Quote:
Originally Posted by KyleLee /forum/post/15491056


09 ultra's are up to 50 xmech (new motor... not out yet)

That's great. But it kind of pisses me off since I just picked up a used 18" Ultra a few weeks ago for $700.
JK. Seriously though If it's going to be $2K or let's say a bargain price on sale at $1400 who's going to buy them? Then there are the issues with availability, warranty service and all that jazz.
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by vasyachkin /forum/post/15490905


are you trying to make me stop liking the LMS ?



why do you want xmax in the 30mm plus range ? dance club and movie theater subwoofers have less than 10 mm xmax and they are the benchmark.


a good 21" subwoofer with just 20mm xmax would easily slaughter basically any driver on the market for bass ( as opposed to huffing and puffing ).


i think you need to slow down and think about what is the real reason for your obsession with xmax? don't make me go all freudian on you

Nah. I own one myself and it is proven to be a great driver. Which would you rather have a driver with 18mm xmax that bottoms at 40mm, or a driver that has 32mm xmax that also bottoms at 40mm? Let's just assume that everything else is the same between the two.


I completely disagree about PA, dance club and movie theaters are the benchmark for bass. Seriously?
Perhaps for efficiency, design optomization, and sheer SPL. Most of these have absolutely nothing going on below 30hz and that is the really good systems. It is a completely different application and is very much bandwidth limited by design. BTW I'm at clubs and around live amplified music 3 or more nights a week and have been for over 10years. I'm very familiar with their strengths and weaknesses.


You need the high xmax so that you can produce the very lowest bass at a loud enough level to matter and for protection of the driver in case a very low bass transient does come through. Without the HPF commonly used in cinema subs and PA bass bins they would be destroyed if a 20-25hz bass transient came through at the levels they are used at, or at least very heavily distorted. And that is not just because they aren't tuned low either. The low xmax drivers just cannot move enough air to properly produce really low bass. Low bass is all about displacement. You know this stuff.
 

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Quote:
Originally Posted by Ricci /forum/post/15492179


Which would you rather have a driver with 18mm xmax that bottoms at 40mm, or a driver that has 32mm xmax that also bottoms at 40mm? Let's just assume that everything else is the same between the two.

if i am the only one who will ever touch the gain knob and i can see the cone of the driver from my listening position then the 32mm one.


if its a ported sub that i am lending out to somebody else to play with then the 18mm one.


as far as 20 hz bass ... well of course 20 hz bass needs large xmax but who needs 20 hz bass ? a few people on this forum do. maybe a few dozen other people.


i bet 95% of people who bought RE XXX didn't buy it for 20 hz bass but simply because they have not the slightest clue about subwoofers and thought the excursion videos on youtube and realmofexcursion are really cool.


i don't think there are enough people in need of 20 hz bass to justify creating a subwoofer for them.


yes dance club and movie theater subs don't have any output below 30 hz and thats precisely because nobody needs it. well maybe i do. maybe you do. so what.


there are some people really concerned with their car being able to do a 9 second quarter mile. nobody builds cars for them even though technically it would be rather easy. you could probably build a car that does 9 second quarter mile for less than what toyota camry costs. still nobody will do it because a few crazy people are not a market.


if you must have that 9 second car you take a normal car like mustang and put turbo on it. and if you must have that 20 hz bass you must take a normal driver like JBL 2269 and put it into a 20 foot long horn.
 

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You think a turbo on a normal mustang would make it hit 9 seconds in the I/4 mile?Think again ..... There are no normal production cars that can hit that..not even the vipers or Ferraris or Bugattis.... 9 seconds= 2400 pound car,750 hp.... If it's geared for the 1/4 it would run out of breath after it. Use to drag for a number of years.
 

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Maybe the 9 second car was not the best example but he does have a point about the market. (it is not as easy as he thinks to get a 9-second car)


Even so, like I said, if it was near the top in performance including SQ when tested there would be a nice DIY segment that would at least desire the drive. Buying it may still be a whole other issue though. If the test results are killer, it would create its own market.


Not everyone wants huge subwoofers in their living space. With the kind of displacement a 21 would give, you could have one serious sub.


I don't agree with the 20 Hz idea either. I think the overwhelming majority of us are after
 
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