Si BM Proto Arrives for testing ( PICS )

[SocMunky 10+ year member]

Two 10's may be interesting, if the output from my tc oem doesn't do it for me....or if the cone flies off the surround...whichever comes first...

 

[Electrodynamic 10+ year member]

So would it be worth it for me to replace my current gen BMs with the new gen models? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Well you'll have to see what Jim has to say about the 12, but I would change them out.

Two 10's would be fantastic in any situation. We're going to put 4 10's sealed in one of our demo vehicles pretty soon. With the front stage the car has, I can see it easily taking away a LOT of 1'st place SQ trophies.

 

[2kchevy06civic 5,000+ posts]

werd. Glad to see the 10" checks out. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Electrodynamic 10+ year member]

werd. Glad to see the 10" checks out. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

The 12" will too. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

From what I remember, Jim said he will be testing the 12" this weekend at Chad's house (which probably means it will be put in both sealed and ported boxes).

 

[adio 5,000+ posts]

what does it take to make a sub be optimal for small sealed and small ported boxes??? i would love to buy some of these along with other subs......... its just that the volume 2 of these takes up would throw me off.

 

[Electrodynamic 10+ year member]

What is it about the drivers that throws you off? The drivers displace less than 0.1 cube each. If it's enclosure modeling you're concerned about, the new BM 10's will work in 0.5-0.7 cubes sealed and 1.5 cubes ported with the 12's working in 1.2 cubes sealed and 1.75-2.0 cubes ported.

The current BM's work in similar enclosures, and we have a few 10's left even though we haven't listed them.

 

[bose301s 5,000+ posts]

Do you know what the port tuning on the new BMs will be best, or is that something you'll have to figure out through more testing later?

 

[adio 5,000+ posts]

What is it about the drivers that throws you off? The drivers displace less than 0.1 cube each. If it's enclosure modeling you're concerned about, the new BM 10's will work in 0.5-0.7 cubes sealed and 1.5 cubes ported with the 12's working in 1.2 cubes sealed and 1.75-2.0 cubes ported.
The current BM's work in similar enclosures, and we have a few 10's left even though we haven't listed them.

just the enclosure sizes. like for instance, i would really like to get some shivas, kicker L series or some dayton DVC, both 12's, but i know those types of subs need large enclosures for both ported and sealed. thats why i'm searching around for some subs that take smaller enclosures.

i'm also looking for some bamboo wood for enclosures. since TC has that HT sub made out of bamboo and it only weighs 44lbs http://www.tcsounds.com/products.htm , i thinks its a great idea instead of using MDF. my 1.67 box weighs so **** much for it to be so small. which chu think about that , Lectro???

 

[lilmaniac2 5,000+ posts]

use birch for lightweight boxes.

And yes jimbo is bringing the 12 up to play too

 

[Electrodynamic 10+ year member]

just the enclosure sizes. like for instance, i would really like to get some shivas, kicker L series or some dayton DVC, both 12's, but i know those types of subs need large enclosures for both ported and sealed. thats why i'm searching around for some subs that take smaller enclosures. i'm also looking for some bamboo wood for enclosures. since TC has that HT sub made out of bamboo and it only weighs 44lbs http://www.tcsounds.com/products.htm , i thinks its a great idea instead of using MDF. my 1.67 box weighs so **** much for it to be so small. which chu think about that , Lectro???

I think bamboo is a way to reduce weight, for sure. Birch plywood is another option to keep weight down. Fiberglass is another.

As far as enclosure sizes go, the new BM's are going to perform well in small to medium sized sealed enclosures.

 

[newusername 10+ year member]

Hoffman's law really dictates that small subs for small enclosures don't work really well; you'll give up either efficiency or low frequency performance. I would say that BM is pretty middle of the pack at the most: in my opinion, it's enclosure requirements are not "big" by any means.

Bamboo is a really expensive approach to cutting down on weight. Go with a good 13 ply void-free birch, apple, etc.

 

[mrogowski 5,000+ posts]

Hoffman's law really dictates that small subs for small enclosures don't work really well; you'll give up either efficiency or low frequency performance. I would say that BM is pretty middle of the pack at the most: in my opinion, it's enclosure requirements are not "big" by any means.
Bamboo is a really expensive approach to cutting down on weight. Go with a good 13 ply void-free birch, apple, etc.

Agreed. Baltic Birch is used widely in pro audio where requirements for light-weight enclosures are even more necessary. Pricing is decent as well.

 

[adio 5,000+ posts]

Hoffman's law really dictates that small subs for small enclosures don't work really well; you'll give up either efficiency or low frequency performance. I would say that BM is pretty middle of the pack at the most: in my opinion, it's enclosure requirements are not "big" by any means.
Bamboo is a really expensive approach to cutting down on weight. Go with a good 13 ply void-free birch, apple, etc.

glad u said this

Hoffman's Iron Law. Of these three things, you can only keep two:

1. Efficiency

2. Low frequency extension

3. Smaller enclosure size

i can keep 2- 3. a bigger amp can help with #1, or so i think

//content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif

 

[Electrodynamic 10+ year member]

This is getting slightly off topic, but you can't get around Hoffman's law. Using a LOT more power still means your efficiency has gone down if you're allowing more room for the other two categories.

Think of the law as a pie chart - if you increase one part, the other two get smaller. Increase two parts and the one part left over gets considerably smaller.

On that note, if enclosure size is 50% of your pie (i.e., a small enclosure), efficiency and low frequency extension will suffer. Sure you can add more power to make up for the loss of efficiency but your low frequency extension is still suffering. Attempts at getting around this have been done many times - take a look at the Sunfire cube subs - super tiny enclosures, LOTS of power, a PR and more EQ boost than you've probably ever seen. The result is a tiny sub that slams but it's not the cleanest on the face of the planet because the driver is working SO hard to produce all that bass.

With the BM's enclosure sizes ranging from 0.5 sealed to slightly over 1 cube sealed for optimum performance, they're a formidable driver for small-to-medium sized enclosures.

 

[adio 5,000+ posts]

This is getting slightly off topic, but you can't get around Hoffman's law. Using a LOT more power still means your efficiency has gone down if you're allowing more room for the other two categories.
Think of the law as a pie chart - if you increase one part, the other two get smaller. Increase two parts and the one part left over gets considerably smaller.

On that note, if enclosure size is 50% of your pie (i.e., a small enclosure), efficiency and low frequency extension will suffer. Sure you can add more power to make up for the loss of efficiency but your low frequency extension is still suffering. Attempts at getting around this have been done many times - take a look at the Sunfire cube subs - super tiny enclosures, LOTS of power, a PR and more EQ boost than you've probably ever seen. The result is a tiny sub that slams but it's not the cleanest on the face of the planet because the driver is working SO hard to produce all that bass.

With the BM's enclosure sizes ranging from 0.5 sealed to slightly over 1 cube sealed for optimum performance, they're a formidable driver for small-to-medium sized enclosures.

u won't believe how much your convincin me to get some of these........ are these sizes for 10's or 12's? did u guys say anything about prices yet?