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Any 18’s on the horizon with XBL^2? - Page 3

post #61 of 711
"Most would agree with me that a single 15A circuit is just enough to drive it. But why get two more drivers that can utilize even more power when one won't be able to give them anymore power."

You're missing the point.

As armystud said, it's about headroom. Music has a very high peak-to-average ratio, and only short term power is required to avoid clipping the peaks.

"You've clipped your Crown? Well there you go..."

? That supports my point and refutes yours; even clipping the amp, which would be about 15 A all by itself, I didn't trip the breaker.
post #62 of 711
Quote:
Originally Posted by Willd View Post

My point is, he already has an Rl-p 18. Most would agree with me that a single 15A circuit is just enough to drive it. But why get two more drivers that can utilize even more power when one won't be able to give them anymore power.

For the 9db extra sensitivity and less distortion, no matter how much power he has on hand.
post #63 of 711
Quote:
Originally Posted by armystud0911 View Post

I thought bass was about headroom, not insane spl's, another 18" sub would give him more headroom

Sure that extra 3db increases the total output and thus allows the individual to turn the volume down to compensate - which in itself increases headroom so you're right about that - but now the individual is still stuck with a far underperforming amp.

To do it right, the person would need a bigger amp to go with the increased amount of drivers. JMO.

Not trying to argue, since it's a difference of interpretations, but IMO, increasing headroom (and output) is about eliminating a short coming. If the driver was within linear limits, but the amp is clipping, the next logical step would be to upgrade the amp. If one keeps the same amp but adds more drivers, it just increases efficency (not that that's a bad thing).
post #64 of 711
Quote:
Originally Posted by Willd View Post

I've been modeling using the prelim paramters and three of Bob's PRs looks to be a good match. Using three of the 2100g PRs, in 340liters the Fb = 15Hz. Giving an anechoic F3 of 16Hz. Not quite an EBS design, but wow. Can take a lot of power too.



PSP has 8" ports now? Or do you mean a pair of 6" PSP ports.

Yea... I'm having a senior moment at the age of 40. They DON'T have 8" ports and I was thinking a pair of 6"s. That is $80 bones though, you can go down to Home Depot and pick-up some 8" or 10" sonotube and make a much more affordable port. Use a 1" roundover bit and you have a flared one too.
post #65 of 711
Quote:
Originally Posted by Looneybomber View Post

Holy oogly moogly. An XBL^2 18" with 33mm xmax. Wow.

Will these have 8.5" or 10" spiders?



Bob at Creative Sound Solutions.
http://www.creativesound.ca/

Currently we are working with standard parts (no special toolings) to keep cost under control so these are 8.5" spiders. The result of that is mostly higher 2nd order distortion components. Not as audible as the higher order products but it will still have higher raw THD numbers than something like the LMS-5400 due to the suspension non-linearities.

We feel its a good tradeoff to make for the cost. We are looking at tooling some parts for a 12" spider but the cost pushes up the price of those types of drivers WAY up. I'm trying to figure out if the market for $1K drivers is large enough to justify doing one.

We can easily design a monster 18" with the same motor BL & Le as the LMS-5400 but will anyone buy it for that kind of asking price? I'd have to sell a couple hundred/year to justify the investment and I'm not sure there are enough on the lunatic fringe to justify it.
post #66 of 711
Quote:
Originally Posted by Willd View Post

My guess is high enough.

But Spezzy, aren't you quite limited w.r.t available power in your room? Like, one 15A circuit? You'd be just able to do a single driver justice let alone two.

Its a 3" all copper VC on black anodized aluminum former. I'd call it 1000W but power handling is one of those nebulous numbers. For most home audio subwoofer failures they are mechanical rather than thermal. I'd say 1 thermal failure to every couple hundred mechanical ones. Its pretty hard to fry the VC first unless you feed it a continuous high frequency test signal at exceedingly high power.
post #67 of 711
Quote:
Originally Posted by armystud0911 View Post

I thought he has a 25cubic foot box? I have driven 4 EP2500's to clipping on a 20amp breaker before with music, you can do some neat stuff, with pink noise and sine wave testing though, the amps shut down often times before the breaker trips due to line sag. Either way though line sag or breaker, one 20 can't drive those amps with tones, but it can for music.

I thought bass was about headroom, not insane spl's, another 18" sub would give him more headroom, they just wouldn't be driven to their limits. This is kind of like Elemental designs A900 subwoofer, it has two decent excursion 18's powered by a 1000 watt plate amp (ok 1300 if you want to go ED's power ratings), that sub can take a lot more power than it does, but it still sounds much better than the single driver version.

Army is right, on continuous test tones you have a limit much lower than the peak power. In real life, music or HT material will idle along and have peak demands, that can be handled by a 15A breaker, at significantly higher output levels.

How much? I don't know.... ask some of the pro-audio amp gurus. They probably have a better idea of what you see in terms of peak power vs. average. It obviously varies a lot at the limits.
post #68 of 711
Quote:
Originally Posted by armystud0911 View Post

Personally Kevin, I am beginning to look for a more to a high output 18 that can be used in small sealed and PR alignments, similar to the LMS 5400. .

Actually this one works in smaller enclosures than the Tempest-X. It looks really good in 7-8 cubic feet with a couple PRs. Since its an 18" it becomes difficult to build into a box too much smaller. About the smallest dimension you could use with a pair of PRs & the driver is a 20" cube. That gets you to about 4.5 cubic feet and you would have a hard time tuning those PRs low enough without MASSIVE amounts of extra weight. If you push the dims out to a 26" cube you have 8 cubic feet (using 0.75" MDF & two braces). Most people will build them taller & deeper to gain the extra cubes. Either way you have to balance size with PR tuning and the smaller the enclosure, the less bandwidth and more power required.

Most of my customers are looking for output. If they want a small box they buy a commercial sub. Guys that are into the DIY market want a big sub that goes deep and loud and they are willing to breath some MDF dust to achieve it.
post #69 of 711
Kevin,

I for one am ready for a ~$1000 sub driver. At this price however I expect 44mm Xmax , 50mm Xmech and enough BL to make this driver suitable for even smaller sealed.


The upper limit per driver can reach $1500. Here the driver would have to surpass the LMS-5400 18" in excusrion and add 10mm to Xmech. It is nice to have 44mm Xmax but of little use if teh Xmech is too close.
post #70 of 711
Quote:
Originally Posted by TheEAR View Post

Kevin,

I for one am ready for a ~$1000 sub driver. At this price however I expect 44mm Xmax , 50mm Xmech and enough BL to make this driver suitable for even smaller sealed.


The upper limit per driver can reach $1500. Here the driver would have to surpass the LMS-5400 18" in excusrion and add 10mm to Xmech. It is nice to have 44mm Xmax but of little use if teh Xmech is too close.

We design for at least 25% more X-mech than X-max. That is just good design practice and I wouldn't bring a driver to market that didn't have plenty of X-mech for the design.

The problem with the small box designs is getting enough power to use the available stroke. As you can see, even on our Maelstrom-X the available power from the wall is getting to be an issue. If we have a small box 18" it would need absolutely enormous amounts of power to use that kind of stroke and still achieve good deep bandwidth.

I'd aim for the LMS-5400 BL curve with 4" VC, plenty of X-mech, and we would pull out some tricks in terms of Le minimization that are expensive, but allow us to make Le extremely linear. The BL curve is pretty easy. The Le tricks are not. Also the tooling required for the suspension improvements are not cheap or easy. Based upon the number of other drivers I sell, I don't think there is enough demand. Of the people willing to pay $1K for a driver, there is a split in the desired product goals. Some people want small box performance, others want large box with high output and deep bandwidth. I'm not sure there is enough consensus for it to be a viable business move.
post #71 of 711
so what are you leaning towards at this point Kevin? what specs are you thinking of, as well as price point?
post #72 of 711
Good points you bring up Kevin.

My feeling is that there are the diy guys who want it to big big and loud. Not huge but they are out there. There are many buying small commercial just because they don't have the information available. The rest fall into the middle ground where they have money to spend but are looking for the best deal and/or are tied down by WAF. We've seen the success of the F113 from form factor and output. Can you get more? Sure can, but I know my F113 has a higher survivablity rate if my place ever gets redecorated if you know what I mean. Small boxes with high output will always have a place, but I don't know if it would be enough to support your business. You may want to consider the car audio market too. They're always looking for small enclosure high spl boxes for their competitions.
post #73 of 711
When you go DIY,serious DIY you do not try to replicate a JL Audio type...tiny box. Not practical at all.

What I and am sure most DIY fanatics look for is great performance is a good sized box(say 12-20cu ft).

For example the Tempest-X 15 incheis a great driver but needs a HUGE box to give me what I am looking for in a good EBS configuration.

A large box is ok (again 12-20cu ft).


Xmech of 25% over Xmax is great and makes the driver more "dumb proof" for those who forget peaks are part of life.
post #74 of 711
Quote:
Originally Posted by JamesK8 View Post

Good points you bring up Kevin.

My feeling is that there are the diy guys who want it to big big and loud. Not huge but they are out there. There are many buying small commercial just because they don't have the information available. The rest fall into the middle ground where they have money to spend but are looking for the best deal and/or are tied down by WAF. We've seen the success of the F113 from form factor and output. Can you get more? Sure can, but I know my F113 has a higher survivablity rate if my place ever gets redecorated if you know what I mean. Small boxes with high output will always have a place, but I don't know if it would be enough to support your business. You may want to consider the car audio market too. They're always looking for small enclosure high spl boxes for their competitions.

There are a lot of commercial offerings in the small form-factor high-output category. The reason is simple. If its a commercial sub you have to ship and service the finished product. That becomes progressively more difficult with larger/heavier subs.

There are not too many commercial subs that are 10-12 cubic feet for those reasons. There is a real engineering advantage to having that large box size. Increasing the box size allows you to go deeper with less power and that is where I view the real niche is for DIY drivers for home audio. Hell.... at 2-4 cubic feet there are literally hundreds of finished subwoofers to choose from, all at very reasonable prices. Hard to go head-head with that and win.
post #75 of 711
Quote:
Originally Posted by Kevin Haskins View Post

Some people want small box performance, others want large box with high output and deep bandwidth. I'm not sure there is enough consensus for it to be a viable business move.

Too bad there wasn't a way to use the same motor/vc, but swap cones and surrounds for each application.
post #76 of 711
Quote:
Originally Posted by Looneybomber View Post

Too bad there wasn't a way to use the same motor/vc, but swap cones and surrounds for each application.

There is if you build them. I don't, we use a build house and you have to do a minimum run. It only becomes economical for "general purpose" designs that you can sell in relatively high volume.
post #77 of 711
Quote:
Originally Posted by ssabripo View Post

so what are you leaning towards at this point Kevin? what specs are you thinking of, as well as price point?

I think the LMS-5400 had a good set of T/S parameters for that kind of driver. I'd maybe aim for slightly larger boxes for the same reasons I've already stated. It would be nice to be able to actually USE all that stroke.

Keep in mind this is just talk. I'm not convinced there is a big enough market for that kind of driver. I'd estimate it would be a $1K driver and TC has had difficulty making money on them I don't know why it would be any different for me.
post #78 of 711
Steve, good point on more drivers increasing efficiency, I forgot all about that.

"If the driver was within linear limits, but the amp is clipping, the next logical step would be to upgrade the amp. If one keeps the same amp but adds more drivers, it just increases efficency (not that that's a bad thing)."

"Just increasing efficiency" gives more output for the same power draw, with further benefit from less power compression in the driver.

So according to the mistaken assumption that the circuit is a limiting factor, that more drivers/volume would be the way to go.
post #79 of 711
Quote:
Originally Posted by noah katz View Post

You're missing the point.

As armystud said, it's about headroom. Music has a very high peak-to-average ratio, and only short term power is required to avoid clipping the peaks.


No, I got the point. I was merely discussing the merit of it. As long as one understands they're merely doing it for efficiency, and headroom that they won't be able to utilize, then by all means.

Quote:


? That supports my point and refutes yours; even clipping the amp, which would be about 15 A all by itself, I didn't trip the breaker.

You have a Crown K2 hooked up to a pair of Avalanche 18s, right? So you're either running ~4ohm a channel or 8ohm bridged, correct? And you've clipped it when nothing else was running on the 20A circuit or only when all the other stuff you listed was as well?

So you're assuming that all the other stuff you listed doesn't pull 5A of current or more and that there is zero line sag occurring, correct?

Quote:


So according to the mistaken assumption that the circuit is a limiting factor, that more drivers/volume would be the way to go.

You mean tossing the assumption that the circuit is a limiting factor aside...and it still is. You could toss 100 drivers in that room, and have the efficiency increased massively, but the circuit would still be a limiting factor.
post #80 of 711
Quote:
Originally Posted by Kevin Haskins View Post

I think the LMS-5400 had a good set of T/S parameters for that kind of driver. I'd maybe aim for slightly larger boxes for the same reasons I've already stated. It would be nice to be able to actually USE all that stroke.

Keep in mind this is just talk. I'm not convinced there is a big enough market for that kind of driver. I'd estimate it would be a $1K driver and TC has had difficulty making money on them I don't know why it would be any different for me.

Making money or selling them? They actually didn't have trouble selling them when they were $875. Most of them were pre-ordered.
post #81 of 711
Quote:
Originally Posted by Kevin Haskins View Post

Its a 3" all copper VC on black anodized aluminum former. I'd call it 1000W but power handling is one of those nebulous numbers. For most home audio subwoofer failures they are mechanical rather than thermal. I'd say 1 thermal failure to every couple hundred mechanical ones. Its pretty hard to fry the VC first unless you feed it a continuous high frequency test signal at exceedingly high power.

Yeah thats what I thought.
post #82 of 711
Quote:
Originally Posted by SteveCallas View Post

For the 9db extra sensitivity and less distortion, no matter how much power he has on hand.

True. I suppose its worth it to some. Just being practical, thats all.
post #83 of 711
Quote:
Originally Posted by Willd View Post

Making money or selling them? They actually didn't have trouble selling them when they were $875. Most of them were pre-ordered.

If I could pre-sell 25 of them I'd do it.
post #84 of 711
Quote:
Originally Posted by Kevin Haskins View Post

If I could pre-sell 25 of them I'd do it.

Well, give it some thought. You never know...
post #85 of 711
It takes more than thought.... it takes $$$$ ;-)

At this time I'm paying for the new Maelstrom-X, the DPL-15 and a new PR. I also have a new plate amp integrating the Woofer Widget to fund so there is a limit to my pocketbook.

Maybe later this year.
post #86 of 711
Thread Starter 
Kevin,

Well, I'll sign up; if I could pick up a pair of the 18" LMS for 1k ea. right now, they'd be headed to KC...

I believe part of the problem was a lack of objective data and availability (among others). The measurements Ilkka performed on the LMS driver certainly has generated considerable interest; now we only need 23 more:-)

Larry

Quote:
Originally Posted by Kevin Haskins View Post

It takes more than thought.... it takes $$$$ ;-)
post #87 of 711
Quote:
Originally Posted by Kevin Haskins View Post

It takes more than thought.... it takes $$$$ ;-)

Kevin,

If you ever offer these drivers with the ubber motor and excursion to match.

I buy. No arguments,no if or but.

Now where is the 18"...please just no monster optimal boxes around 40cu ft...as when you reach the size of a huge fridge...it is no longer WAF...it gets a bit overboard.Remember I have to fit in the near future eight 13cu ft (internal volume)subs in that room. So I have around 50 cu ft free...to fit two huge subs.

Up to 20cu ft per driver is ok with me(ha the small sub maniac of years past).
post #88 of 711
You don't need 44mm of xmax or even 38mm xmax to get me interested, as we already discussed, those ideas are just too impractical, even in large ported enclosures, it can be hard to use that much excursion, as you know, you need 4x the power to get the driver to do twice the excursion. I'd be psyched about an 18 with ~30mm xmax. It would be real nice to have a lower qts, that way we could 6-7 cubes sealed and yield a critically damped box, unlike our current high excursion 18" offerings. Your right, super tiny enclosures for PR's don't make sense either, too much mass is required and its too hard on the PR's. But I would love it if we could do 8 cubes or so tuned to ~15Hz with a pair of 18" PR's. A hp filter would be in order, but as I see it, there is just no need to do insane excursion due to the how prohibitive it can be, requiring beefier PR's, more power, higher cost ect. What would be nice is a target price right around $650 or so, kinda like an 18" tumult. That way you wouldn't price yourself outside of the market and could still generate enough demand to keep costs down and profits up a bit. If it can't be done, hey it can't be done, thats fine, its just what I think would revolutionize the diy market.
post #89 of 711
Thread Starter 
EAR,

I'm really glad we have you as part of this community; I can only imagine what your place must be like:-)

btw - Kevin's 18 models well anywhere between 8-12ft.^3...

Larry

Quote:
Originally Posted by TheEAR View Post

Kevin,

If you ever offer these drivers with the ubber motor and excursion to match.

I buy. No arguments,no if or but.

Now where is the 18"...please just no monster optimal boxes around 40cu ft...as when you reach the size of a huge fridge...it is no longer WAF...it gets a bit overboard.Remember I have to fit in the near future eight 13cu ft (internal volume)subs in that room. So I have around 50 cu ft free...to fit two huge subs.

Up to 20cu ft per driver is ok with me(ha the small sub maniac of years past).
post #90 of 711
Quote:
Originally Posted by 04FLHRCI View Post

Kevin,

Well, I'll sign up; if I could pick up a pair of the 18" LMS for 1k ea. right now, they'd be headed to KC...

I believe part of the problem was a lack of objective data and availability (among others). The measurements Ilkka performed on the LMS driver certainly has generated considerable interest; now we only need 23 more:-)

Larry

I agree.... Ilkka's measurements generated a lot of interest. But here is part of the problem. You where going to buy a pair of Maelstrom's so I just lost a sale.

All joking aside, I'd send a unit to Ilkka for 3-rd party measurements. He needs a chamber though.... those outdoor THD measurements are highly suspect. I have access to a good chamber which would actually give more accurate THD measurements but nobody would trust me.
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