New Mag and BM thread

[Electrodynamic]

Here it is: The thread that will explain exactly what the new Mag's and BM's will feature. There will be no color options, coil options, cone options, size options, etc.

New Mag:

The new Mag D2 will be available in 12" only.
It will also be available in Dual 2 Ohms only.

Recommended sealed enclosure volume is 0.8-1 cubic foot sealed.

The enclosure recommendation is after driver displacement. The new Mag will displace ~0.09 ft^3

The new Mag D2 will feature:

3" voice coil
an XBL^2 equipped motor
5.5" deep mounting depth
Motor is inside the basket, hence the shallow depth
Copper anodized pole piece for a built-in shorting ring
Paper pulp cone
Rubber surround
Sewn-on vc leads
Flush gasket (no holes showing)
1000 watt power handling in the recommended enclosure (read, power handling, NOT a power requirement. The New Mag will be happy with anything from 500 watts to 1000 watts)

$249 shipped within the lower 48 states.


New BM:

The new BM will be available in 12" only.
It will also be available in dual 4 Ohm vc configuration only.

Recommended sealed enclosure volume is 0.5 cubic feet.*

The enclosure recommendation is after driver displacement. The new BM will displace ~0.07 ft^3

2.5" VC
XBL^2 equipped motor
3.5" mounting depth
Motor housed inside the basket
Aluminum shorting ring
The cone will be a rohacel core sandwiched between two layers of Nomex
Inverted foam surround for maximum clearance
Flush gasket (no holes showing)
500 watt power handling (read, power handling, NOT a power requirement. The new BM will be happy with anything from 200 watts to 500 watts)

$149 shipped within the lower 48 states.

* Testing will be performed to determine if ported will be an option when the prototype arrives *

[hobie1dog]

I'm excited

[pKelly]

From a customer's standpoint, on what order will the output be compromised by going with only two BM's as opposed to 4 BM's, assuming all other factors are constant?

[hobie1dog]

Originally Posted by pKelly

From a customer's standpoint, on what order will the output be compromised by going with only two BM's as opposed to 4 BM's, assuming all other factors are constant?

The laws of physics are upon us....Nick will explain.

[Electrodynamic]

Originally Posted by pKelly

From a customer's standpoint, on what order will the output be compromised by going with only two BM's as opposed to 4 BM's, assuming all other factors are constant?

Well lets take a look at how the 4 drivers vs. 2 drivers quandry works out:

4 drivers are double the displacement compared to 2 drivers. Double the displacement (surface area and stroke) equals a significant 3 dB increase just by itself. Keep in mind this is assuming that your power input is the same even though your impedance has changed going from 2 drivers to 4 drivers.

Taking a look from sheer surface area alone lets look at the BM's. Each BM has an Sd of 420 cm^2. Two BM's have 840 cm^2 of surface area. Four BM's have 1680 cm^2 of surface area. Double the surface area equals a 3 dB increase.

Now, depending on how you have the drivers situated on the baffle you can get a significant increase from coupling affect too. When you cluster drivers together (in this case it would be two woofers on top and two woofers directly underneath) coupling affect adds a few dB to your output. Typically with 4 drivers vs. 2 drivers you should only see a 3 dB increase in output. Clustering the drivers together you can see gains in the 4-5 dB neighborhood. The reason for this is the air inbetween the drivers tends to get excited as well, which accounts for the increase in output. The increase in output also brings with it increased bottom end because instead of 4 12's you now have slightly more air being excited by the cluster of drivers and you end up with more bottom-end output by more air being excited than what 4 12's would typically do.

However, you get a little bit of coupling affect even if they're side-by-side. You won't see the extra 1-2 dB on top of the 3 dB from doubling your surface area when you have every driver next to each other like you will with four drivers clustered on top of each other, but you will see a tad more than expected. The major benefit no matter how you orient the drivers is low-end output. The low-end is always more solid, louder, and more controlled. Remember that every time you double your surface area that each driver has to work half as hard as it did before. Having to work half as hard means your drivers stay more linear (less Xmax per overall output), which means they stay more accurate.

[pKelly]

Originally Posted by Electrodynamic

Well lets take a look at how the 4 drivers vs. 2 drivers quandry works out:

4 drivers are double the displacement compared to 2 drivers. Double the displacement (surface area and stroke) equals a significant 3 dB increase just by itself. Keep in mind this is assuming that your power input is the same even though your impedance has changed going from 2 drivers to 4 drivers.

Taking a look from sheer surface area alone lets look at the BM's. Each BM has an Sd of 420 cm^2. Two BM's have 840 cm^2 of surface area. Four BM's have 1680 cm^2 of surface area. Double the surface area equals a 3 dB increase.

Now, depending on how you have the drivers situated on the baffle you can get a significant increase from coupling affect too. When you cluster drivers together (in this case it would be two woofers on top and two woofers directly underneath) coupling affect adds a few dB to your output. Typically with 4 drivers vs. 2 drivers you should only see a 3 dB increase in output. Clustering the drivers together you can see gains in the 4-5 dB neighborhood. The reason for this is the air inbetween the drivers tends to get excited as well, which accounts for the increase in output. The increase in output also brings with it increased bottom end because instead of 4 12's you now have slightly more air being excited by the cluster of drivers and you end up with more bottom-end output by more air being excited than what 4 12's would typically do.

However, you get a little bit of coupling affect even if they're side-by-side. You won't see the extra 1-2 dB on top of the 3 dB from doubling your surface area when you have every driver next to each other like you will with four drivers clustered on top of each other, but you will see a tad more than expected. The major benefit no matter how you orient the drivers is low-end output. The low-end is always more solid, louder, and more controlled. Remember that every time you double your surface area that each driver has to work half as hard as it did before. Having to work half as hard means your drivers stay more linear (less Xmax per overall output), which means they stay more accurate.

Awesome read, Nick. I wasn't expecting the detail, but it's very much appreciated. Knowledge is, after all, power. I'll be in Physics II next semester, it's a study of the physics of electric and magnetic fields, electromagnetic waves, and optics via differential equations. I'm excited, and I'll wow the class with the above

I'm super excited for these to be release; never did I imagine I'd have four 12" subwoofers in a crew cab pickup

[M-Special]

So, I'm curious...how does XBL^2 compare to other linear motor technologies i.e. JBL Differential Drive, TC/AP LMT with the uneven voice coil winding? Are these just different ways of reaching the same goal? Is there one that works better than the others? I realize these are very different drivers with different applications, but aside from those differences are these techniques all aiming for the same result?

[Electrodynamic]

Originally Posted by M-Special

So, I'm curious...how does XBL^2 compare to other linear motor technologies i.e. JBL Differential Drive, TC/AP LMT with the uneven voice coil winding? Are these just different ways of reaching the same goal? Is there one that works better than the others? I realize these are very different drivers with different applications, but aside from those differences are these techniques all aiming for the same result?

They're all aiming towards the goal of increasing linear throw. However, linear throw isn't the only thing to be concerned about. JBL's Differential Drive and a lot of the TC LMT motors still don't add up to XBL^2 when it comes to two things: Inductance and Moving Mass. XBL^2 all by itself offers a much shorter coil height than any other topology, which gives any driver equipped with it a much lower moving mass and much lower inductance compared to other topologies.

Now, there are tricks that the mfg's can do to lower inductance such as sleeves or caps. However, most of the time they go overboard and over-ring (shorting ring) the driver and the inductance still ends up being non-linear once the driver starts moving. It might measure low while T/S'ing the driver (T/S's are usually taken at a VERY low imput level) but it can still lack linearity over stroke.

LMT is a HUGE design - meaning the tooling and overall production cost is through the roof, hence the $1800 price tag for a single driver. Not to mention the design problems such as a massive gap to accomodate the variable voice coil windings (and it's a HUGE voice coil).

But anyway, the important things to note are how XBL^2 is not only physically smaller but how it also improves linearity and reduces inductance.

Take a look at what we are doing with the new Mag's - a MUCH smaller design, MUCH more linear T/S's, and a LOT lower inductance.

[M-Special]

So I take it you will not be buying any of the TC patents up for auction then...

Oh yeah, not that I'm complaining but I was wondering why the new mag will only be built in a 12" size. Again, 12" is perfect for my needs, and I don't really care but I was curious.

[Electrodynamic]

Originally Posted by M-Special

So I take it you will not be buying any of the TC patents up for auction then...

Oh yeah, not that I'm complaining but I was wondering why the new mag will only be built in a 12" size. Again, 12" is perfect for my needs, and I don't really care but I was curious.

Haha, nope, I won't be buying any of the patents. The only one that's worth anything is the basket. The surround patent isn't of use to us at all. I'll let the big-boys fight over the basket patent. The results will be interesting...especially if the build house that owns the tooling wins the auction. Then the basket will be an open tool for anyone to use.

The new Mag is being built in a 12" size because 12" subs have out-sold every other size by a factor of at least 2-to-1. When the 15" Mag's were hot, we sold 2 Mag 12's for every single 15" Mag we sold. We also sold 4 Mag or BM 12's for every single 10" BM we sold.

Our specialty has always been 12's. That's where we started. We expanded from there and made other sizes in multiple series's (successfully too, might I add...the other drivers kicked ass).

But what it all boils down to is that I've spent a LOT of time just on the 12" size. By a lot of time, I mean two years. Sure I've "narrowed" my market, but I don't care. It doesn't bother me because I know that I've spent all of my time and energy to bring forward the most technologically advanced, best-sounding, Mag we've ever produced. The 12" only idea is specialization at its finest. I didn't cut any corners by trying to bring an 8, 10, 12, 15, and 18. Instead of messing around with different sized moving assemblies on the same motor (which is what almost ALL companies do), I spent all of my time working on a single size.