# Case I'm the only one who missed these..



## T3mpest

Looks like BMS has a new driver out, new to me at least lol..

Overview

I've used the 8n515 in my last car for about a year.. It had a very clean and natural midrange, almost laid back sounding compared to some pro audio drivers. Not as snappy in the midbass as some other other, but again, very well behaved, and the could def get loud and were very low distortion. Things could practically be played full range if you felt like it lol. These are slightly lower sensativity with higher xmax, probably work very well as a dedicated midbass, and appear to have good midrange extension if you wanted. BMS calls it a midrange, but it looks like it's midbass capable for sure. Anyway BMS def makes nice stuff for good prices, I bet these are no exception.


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## thehatedguy

I thought you were talking about this for a second  :

BMS introduces the new 4599ND 2" dual diaphragm driver


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## Eric Stevens

thehatedguy said:


> I thought you were talking about this for a second  :
> 
> BMS introduces the new 4599ND 2" dual diaphragm driver


Ready for that large format 3 way front end?


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## cajunner

thehatedguy said:


> I thought you were talking about this for a second  :
> 
> BMS introduces the new 4599ND 2" dual diaphragm driver



scary!


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## thehatedguy

It's only 145dB on a plane wave tube with 1 watt...and will take 400 at 300 hertz and up.

Pfff...123 dB sensitivity and can be wired for 4 ohms...



Eric Stevens said:


> Ready for that large format 3 way front end?


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## mikey7182

thehatedguy said:


> It's only 145dB on a plane wave tube with 1 watt...and will take 400 at 300 hertz and up.
> 
> Pfff...123 dB sensitivity and can be wired for 4 ohms...


Finally, a 180db-capable front end for those bulletproof window SPL guys. Fire engine sirens across the world are running for cover.


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## thehatedguy

18" midbasses would be needed I would think.


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## subwoofery

thehatedguy said:


> 18" midbasses and 15" midranges would be needed I would think.


Edited  

Kelvin


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## cajunner

first one to post a cut-away of the innards, gets an "attaboy" out of me...


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## T3mpest

thehatedguy said:


> 18" midbasses would be needed I would think.


Ok... I got this then! So I run my 21's up to 400hz or so on 2kw per side each.. Bridge a leviathan to the 4599ND and run those up to 4-8k or thereabouts.. Midbasses should be good for mid 130db's low 140's with cabin gain.. So the horns won't have to work too hard  Just gotta find tweets


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## Patrick Bateman

cajunner said:


> first one to post a cut-away of the innards, gets an "attaboy" out of me...


I'm betting it'll look a lot like a JBL D2430K, but larger:










If you check out the press releases from JBL you'll see these clues:

1) JBL began using BMS technology about five years ago. They switched from using expensive beryllium diaphragms in their top of the line, to relatively simple and cheap mylar rings.
2) The achilles heel of the ring radiators is displacement; due to the fact that a ring has less area than a dome, the output potential is lower at the xover point
3) Putting *two* rings face to face solves this problem. And the solution is only possible with a ring; you can't do this with a dome.
4) JBL's own press releases make it clear that they're coming out with a whole line of these, both larger and smaller than the D2430K

Note that these are surprisingly attainable; I bought the baby brother to that driver online for something like $105. The real D2430K is available on eBay for fairly cheap.


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## cajunner

I've kept an eye out, maybe I'm not looking for the right driver...

it would be nice, if it could go down to 800 hz or lower, using perhaps less durable diaphragms, since you would only need to have them play a few watts in the car.

if they do look like the JBL, but in a bigger form factor... I am wondering who is going to be the first one to mount them in a vehicle, haha...


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## thehatedguy

The JBLs have been on eBay a few times as of late for about $3-400 each.


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## thehatedguy

JBL Professional D2430K D2 Dual Diaphragm Dual Voice Coil Compression Driver | eBay

Used JBL Pro D2430K D2 Dual Diaphragm Dual Voice Coil Compression Driver | eBay


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## TheScottishBear

18" midbass 15” midrange... Now were talking.


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## thehatedguy

Those drivers are 123 dB efficient and handle 400 watts at 300 and up...who needs midranges? Those things would probably be good to 100 hertz and up with the power we use in a car or house...if your horn was big enough. Hell, you probably could play them that low in a car without a horn or unloaded in a smaller horn and never damage the driver.


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## T3mpest

thehatedguy said:


> Those drivers are 123 dB efficient and handle 400 watts at 300 and up...who needs midranges? Those things would probably be good to 100 hertz and up with the power we use in a car or house...if your horn was big enough. Hell, you probably could play them that low in a car without a horn or unloaded in a smaller horn and never damage the driver.


I may be crazy enough to try this.. I gotta see if I can fit them tho as well as find or build some horns that it could mount too.. dont think I have any Id fullbodies left. chopping minis up wont help because of the reflector. That'd be a crazy 2 way.. horns from 400hz and up 21inch midbasses from 400hz and down.. I'd it didn't work I could always add a midrange or tweeter afterwards lol.


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## T3mpest

Patrick Bateman said:


> I'm betting it'll look a lot like a JBL D2430K, but larger:
> 
> 
> If you check out the press releases from JBL you'll see these clues:
> 
> 1) JBL began using BMS technology about five years ago. They switched from using expensive beryllium diaphragms in their top of the line, to relatively simple and cheap mylar rings.
> 2) The achilles heel of the ring radiators is displacement; due to the fact that a ring has less area than a dome, the output potential is lower at the xover point
> 3) Putting *two* rings face to face solves this problem. And the solution is only possible with a ring; you can't do this with a dome.
> 4) JBL's own press releases make it clear that they're coming out with a whole line of these, both larger and smaller than the D2430K
> 
> Note that these are surprisingly attainable; *I bought the baby brother to that driver online for something like $105.* The real D2430K is available on eBay for fairly cheap.


What driver is that exactly? Any subjective listening impressions from it yet? 300 per driver while a bargain for what your getting, is still a tough pill to swallow, 105 a driver is very doable..


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## thehatedguy

He's been messing around with the 2408H-1 for a bit.

But you aren't really going to get much past 1.5k out of them and would probably be better up around 1.8k.

Right now you can find (in a blue moon) those drivers going for $40-80 ea used. And most of the time they are now in the $140 ea range...and IMO at $140 ea I would buy something else like the Celestion CDX1-1425. And I know a person who could get you better than retail pricing on the Celestions...wink wink.


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## cajunner

those D2430K are all over the place! They've even got one starting at 250, 10 day auction..

that would be pretty cool...

too bad near 400 is out of range right now.

Nobody's come forward with a D2 build yet, that would be "top of the range" in the parlance...

of our times.


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## cajunner

thehatedguy said:


> Those drivers are 123 dB efficient and handle 400 watts at 300 and up...who needs midranges? Those things would probably be good to 100 hertz and up with the power we use in a car or house...if your horn was big enough. Hell, you probably could play them that low in a car without a horn or unloaded in a smaller horn and never damage the driver.



The whole footwell is the horn !


think of it now, a couple of cans of Great Stuff, a thin layer of fiberglass, custom 200 hz Edgar Horns comin' at you from 18 inches away...





those bad boys would put the fear of the Almighty in ya, First Watt, anyone...?

You could go single ended triode whatever, a half a watt is "good enough!" in the car, considering you'd be down what, to 123 db, (both horns...)


ridiculous..


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## edzyy




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## Patrick Bateman

T3mpest said:


> What driver is that exactly? Any subjective listening impressions from it yet? 300 per driver while a bargain for what your getting, is still a tough pill to swallow, 105 a driver is very doable..


I was really hoping that they would sound magical, but to my ears, they're basically indistinguishable from the Celestion CDX1-1425.

But they're insanely efficient. I haven't measured them head-to-head but I'd be willing to bet they're six dB more efficient. They are probably the loudest compression driver I've ever tested.


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## edzyy

mikey7182 said:


> Finally, a 180db-capable front end for those bulletproof window SPL guys. Fire engine sirens across the world are running for cover.




What kind of horn would these fit on? 

My friend is re-building his "street battle" car & these might be a worthwhile option.

A couple beyma 8g40's in the door & those covering 400-500hz up would be insane

Not exactly SQ, but not the goal.


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## thehatedguy

Something BIG if you wanted to load them down to 3-400 hertz.


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## edzyy

Welp, looks like we're not getting these under the dash of a Dodge Challenger


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## cajunner

I read that the Veritas horn design is good for under 500 hz, or maybe that it doesn't significantly degrade the compression driver's output until that low.

I would guess, if you could extend the Veritas another 4 inches wide, and let it expand vertically another inch of height, you might be able to reach 450 hz, legitimately.

It would take a nearly complete re-work of the horn but you have the original to work from. 

I don't believe Eric's full bodies can drive down quite as far, but wasn't Richard Clark's special ones, able to reach 430 hz?


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## thehatedguy

They would be way too large to physically fit inside the car...I've made some 1/3rd sized 250 hertz horns, and they were much larger than what cajunner is describing.

Width and height are only 2 of the 3 pieces you need to get the horn to load down that low.


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## thehatedguy

Oh hell no, not a chance.

Only chance you would have would be an old one that you cut the firewall out of.



edzyy said:


> Welp, looks like we're not getting these under the dash of a Dodge Challenger


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## edzyy

Back to the drawing board! Getting louder is becoming difficult.


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## cajunner

just stick them in the back seat.

They will be so loud that you won't be able to localize on them anyway, anything over 130 db in the car and it sounds like it's inside your head anyway, the whole hearing apparatus thing is overloaded and you just get intensity differences.


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## Patrick Bateman

edzyy said:


> Back to the drawing board! Getting louder is becoming difficult.


huh?

I can do 200hz on a $30 waveguide that's readily available from MCM or Parts Express.

Synergy horns solve this problem nicely.

If it's not loud enough, just add more mids, problem solved.


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## Patrick Bateman

cajunner said:


> The whole footwell is the horn !
> 
> 
> think of it now, a couple of cans of Great Stuff, a thin layer of fiberglass, custom 200 hz Edgar Horns comin' at you from 18 inches away...
> 
> 
> 
> 
> 
> those bad boys would put the fear of the Almighty in ya, First Watt, anyone...?
> 
> You could go single ended triode whatever, a half a watt is "good enough!" in the car, considering you'd be down what, to 123 db, (both horns...)
> 
> 
> ridiculous..


All of this can be achieved cheaply, no need for a D2.
Basically you can wedge a waveguide into the firewall, and if you can get a close match between the wall angle and the corner, the corner extends the horn to infinity.

There's going to be a transition at the waveguide mouth, but once you deal with that, you're good to go. It's a piece of cake to raise the efficiency of a driver by ten decibels on a horn. So if you use an array of four drivers with an efficiency of 90dB, *you're looking at an efficiency of 106dB on the horn.* Find something that can handle 125 watts and you can easily exceed 130dB at midrange frequencies.










I know I have a habit of using Synergy horns for *everything*, but in this case, there really isn't a solution that can beat it. I think people would be shocked at how loud an array of small drivers on a compound horn can get, and if you were truly nuts and used an array of prosound drivers, it would be deafening. The Jericho J2 hits 150dB in the midrange. Now, admittedly, it has twenty four mids, but that's what it takes!


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## thehatedguy

Now just imagine what the J2 would do if Tom put those big BMS midrange compression drivers on it in place of the cone drivers...he would be able to start fires from the output.

I guess I am the number 2 fan boy of the Unity/Synergy horns on the forum...they are pretty cool, I just couldn't get a way for them to work in my car in the space I have. Now, if I got another Zapco DC Reference amp like a 360.4 or a 500.1, I could have more flexibility in laying things out...like an active 4 way system or a passive 4 way between the mids/highs and active elsewhere.


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## edzyy

Patrick Bateman said:


> huh?
> 
> I can do 200hz on a $30 waveguide that's readily available from MCM or Parts Express.
> 
> Synergy horns solve this problem nicely.
> 
> If it's not loud enough, just add more mids, problem solved.


We've hit an SPL plateau in the midrange frequencies & ran out of space in the front doors for more mids. 

They're 4 audax pr170m0's, 2 10" fe200's & a bunch of bridged p900.4's for power. 

And he wants louder :laugh:

Not quite sure what the next step is.


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## Patrick Bateman

edzyy said:


> We've hit an SPL plateau in the midrange frequencies & ran out of space in the front doors for more mids.
> 
> They're 4 audax pr170m0's, 2 10" fe200's & a bunch of bridged p900.4's for power.
> 
> And he wants louder :laugh:
> 
> Not quite sure what the next step is.


Basically you have to get everything closer together. That quarter wavelength thing rules over everything. To get four midranges to sum at 1khz they have to be within 3.375" of each other.









Danley's Pyramid works nicely...









But placing the diaphragms face to face, is the same idea, but taken to it's logical extreme.









^^^ Setups like this will only work up to about 300 or 400hz. Above that, you'll get output, but it's going to start rolling off due to destructive interference.


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## edzyy

Soooo anyone try these yet?


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