Speakerplans.com Homepage
Forum Home Forum Home > Plans > Scoops
  New Posts New Posts RSS Feed - B&C's 21 Inch Woofer.
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

B&C's 21 Inch Woofer.

 Post Reply Post Reply
Author
Message
Elliot Thompson View Drop Down
Old Croc
Old Croc
Avatar

Joined: 02 April 2004
Location: United States
Status: Offline
Points: 5365
Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Topic: B&C's 21 Inch Woofer.
    Posted: 18 May 2007 at 4:30pm
I found this on their site last night updating my driver database. It's Scoop material so, you might find it useful.

B&C 21 SW150

Best Regards,

Elliot Thompson
Back to Top
mykey View Drop Down
Old Croc
Old Croc


Joined: 18 August 2005
Location: UK/Indonesia
Status: Offline
Points: 9680
Post Options Post Options   Thanks (0) Thanks(0)   Quote mykey Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 2:02pm
thats disapointing
 
neo
Back to Top
Elliot Thompson View Drop Down
Old Croc
Old Croc
Avatar

Joined: 02 April 2004
Location: United States
Status: Offline
Points: 5365
Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 3:13pm
That's what happens when the majority complain about heavy speakers.

Best Regards,
Elliot Thompson
Back to Top
TONY.A.S.S. View Drop Down
Old Croc
Old Croc


Joined: 21 February 2007
Location: United Kingdom
Status: Offline
Points: 6867
Post Options Post Options   Thanks (0) Thanks(0)   Quote TONY.A.S.S. Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 4:10pm

I think neo's have been worth a look because the ones that I have seen and used so far have had a stonger motor than the conventional equivelent. In the end, it is the performance that counts, but I think at the moment that there still may be a sycological barrier because of the visual difference in magnet size. agree, disagree?
Back to Top
Elliot Thompson View Drop Down
Old Croc
Old Croc
Avatar

Joined: 02 April 2004
Location: United States
Status: Offline
Points: 5365
Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 4:36pm
I agree.

The abuse factor is something to consider as well. When you have ample amount of drivers, you tend not extract every bit of SPL from your speakers.

Those usually complaining about neos tend to always drive their speakers beyond its limits. It usually stems from a lack of understanding on their part, playing a venue that is too big, or a combination of both.

It's like Digital versus Analog recording. Both will get the job done however, one will not tolerate the same amount of abuse when driven beyond it's limits.

Best Regards,






Edited by Elliot Thompson - 19 May 2007 at 4:39pm
Elliot Thompson
Back to Top
gazman View Drop Down
Registered User
Registered User


Joined: 30 January 2006
Status: Offline
Points: 100
Post Options Post Options   Thanks (0) Thanks(0)   Quote gazman Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 8:43pm

Completely agree RE: the abuse factor affecting some peoples views of neo magnets. 

Probably many of these people have been driving drivers far past their thermal limits, either by just too much power...but more probably heavy clipping, and then experiencing demagnetisation. I don't see that side effect of neo's worth mentioning even if gear is run right in the first place!
 
Think you're right Tony, people see the little magnet and psychologically think crappy driver. That B&C 21" has the highest BL motor force I've ever seen in a driver, higher than the PD 21" ceramic magnet that weighs twice the weight and having a slightly larger xmax and higher power handling.
 
As long as power compression is up their with the PD (and knowing B&C it probably is...) then this could be quite a beast of a driver.
Back to Top
ceharden View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 11851
Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 19 May 2007 at 10:47pm
I'm very tempted to use one in a large bandpass box for 'proper' sub useage from about 60Hz down.  21" and 15mm of Xmax is a lot of air movement.  What d'ya reckon, flat to about 25-30Hz is possible?  I'll get round to simulating it one day....
Back to Top
Tekasis View Drop Down
Old Croc
Old Croc


Joined: 03 July 2006
Status: Offline
Points: 6492
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tekasis Quote  Post ReplyReply Direct Link To This Post Posted: 20 May 2007 at 12:43am
So what do you all make of the following posts then ?
 
Quote As I said before in other topic, Neo is not very good for high power drivers.

be careful, Neodynium magnets, even made with the best grade, cannot sustain more than 100 degres Celesius without magnet field loss. For examples, N40SH grade used by B&C and RCF are sujet to magnetic fiel reduction if working above 75 degres (Neo SH is rated 150 degres). That's why I think it's not a good idea to use Neo magnet for big power  subwoofers, the long term/high power efficiency is not good. Ferrite is still the best solution

to illustrate my words, a test with N40SH grade magnet showing demagnituzation field vs temperature...




All in one, for drivers more powerful than 600W AES RMS, Ferrite is much much better.
 
 
How many people out there do you think believes in the temperature issue with Neo drivers ? Must be loads.  
 
Back to Top
TONY.A.S.S. View Drop Down
Old Croc
Old Croc


Joined: 21 February 2007
Location: United Kingdom
Status: Offline
Points: 6867
Post Options Post Options   Thanks (0) Thanks(0)   Quote TONY.A.S.S. Quote  Post ReplyReply Direct Link To This Post Posted: 20 May 2007 at 1:45am

It was Clive West when he was the designer at PD that showed me the first slug of neo that I'd seen.He also told me about the heat issue. That was more than 10 years ago.Since then I have seen speaker chassis redesigned to become more effective in the heat sink department. I also think it unlikely that manufactures will print false claims, because they would have a lot to answer for under their garuantee. To have confidence in your equipment you have to find things out for yourself, so get the units and run the tests.
A while back we made a pair of column speakers for a local band. They wanted a retro look. Their columns are 4x12 neos with a 2"comp. and horn. Believe me, this little system gets thrashed, they get the sound they want, and everybody's happy. so far so good.
Back to Top
Tekasis View Drop Down
Old Croc
Old Croc


Joined: 03 July 2006
Status: Offline
Points: 6492
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tekasis Quote  Post ReplyReply Direct Link To This Post Posted: 20 May 2007 at 11:44am
Originally posted by Elliot Thompson Elliot Thompson wrote:

It's like Digital versus Analog recording. Both will get the job done however, one will not tolerate the same amount of abuse when driven beyond it's limits.
 
Which ones ? The Neos or Ferrite ?
 
Back to Top
Elliot Thompson View Drop Down
Old Croc
Old Croc
Avatar

Joined: 02 April 2004
Location: United States
Status: Offline
Points: 5365
Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 20 May 2007 at 3:09pm
The question should be,

Why would you want to drive a speaker beyond its limits?

You'll just increase the distortion to the point of it sounding terrible going that route. The picture you posted reinforces what I said about those who drive their speaker beyond their limits.

If guys are worrying about which driver will last longer beyond their limits then, they are not aiming for quality they just want a bunch of drivers to create a lot of noise.

Having ample amount of drivers decreases the need to overdrive your woofers because you will achieve the output needed without driving them close or beyond their limits.



Best Regards,








Elliot Thompson
Back to Top
Tekasis View Drop Down
Old Croc
Old Croc


Joined: 03 July 2006
Status: Offline
Points: 6492
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tekasis Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 2007 at 10:03am
Originally posted by TONY.A.S.S. TONY.A.S.S. wrote:

 To have confidence in your equipment you have to find things out for yourself, so get the units and run the tests.
 
Agreed 100%
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.08
Copyright ©2001-2026 Web Wiz Ltd.