BillFitzmaurice.info - View topic - SLA BMR drivers
View unanswered posts | View active topics It is currently Wed Oct 22, 2014 11:27 pm



Reply to topic  [ 54 posts ]  Go to page 1, 2, 3, 4  Next
SLA BMR drivers 
Author Message

Joined: Sat Apr 21, 2012 9:17 pm
Posts: 62
Location: Adelaide, Australia
Post SLA BMR drivers
Hey all,
Planing to build a sla centre and possibly tlah mains sometime soon.
Found a new possible driver on parts express. Hiwave 3.5" balanced mode radiator full range
speakers which weigh 0.3lbs each for reasonable shipping to Aus. Not really
sure about BMR drivers and wondering what people think about feasibility in a SLA or TLAH.

http://www.parts-express.com/pe/showdet ... r=297-2156

http://www.hi-wave.com/downloads/datash ... C20F-8.pdf

_________________
TTLS 17"
THT 24.5"
2x THT 16"
SLA LCR
Otop12 x2
Titan 48 24"


Last edited by Chompy191 on Fri Dec 07, 2012 8:25 pm, edited 2 times in total.



Sat Oct 20, 2012 12:25 am
Profile
Site Admin
User avatar

Joined: Tue May 02, 2006 5:59 pm
Posts: 23488
Post Re: SLA / TLAH BMR drivers?
Looks fine except for the midrange dip. It should be able to run full range.


Sat Oct 20, 2012 7:41 am
Profile

Joined: Thu Oct 05, 2006 7:31 pm
Posts: 297
Location: Wichita, KS
Post Re: SLA / TLAH BMR drivers?
What the heck is, "bending wave technology and pistonic operation"? Somebody in sales must be using a thesaurus. Or the tech staff just got tired of going unnoticed.


Sat Oct 20, 2012 8:04 am
Profile

Joined: Tue Oct 30, 2007 7:29 pm
Posts: 70
Location: Milton Keynes, England
Post Re: SLA / TLAH BMR drivers?
Chompy191 wrote:
...which weigh 0.3lbs each for reasonable shipping to Aus...


685g is closer to 1.5 lb - might well be a deal breaker

A


Sat Oct 20, 2012 11:03 am
Profile

Joined: Sat Apr 21, 2012 9:17 pm
Posts: 62
Location: Adelaide, Australia
Post Re: SLA / TLAH BMR drivers?
Balanced Mode Radiator (BMR), a hybrid technology that blends DML technology with that of traditional pistonic-action loudspeakers.[3] According to NXT, the resultant speakers feature the low-frequency performance of a traditional loudspeaker, but with a wider directivity and shallower profile, as well as the mid-range and high-frequency performance of a DML.

Distributed Mode Loudspeaker (DML) is a flat panel loudspeaker technology, developed by NXT[citation needed], in which sound is produced by inducing uniformly distributed vibration modes in the panel through a special electro-acoustic exciter
Source
http://en.wikipedia.org/wiki/Distribute ... oudspeaker

So from what I can determine these use the hybrid technology so for the mids and highs use the DML technology with much wider dispersion. So these would eliminate the need for tweeters? (would save a heap of money). Might have to order some before parts express change the listed weight. Cambridge minx speakers use BMR drivers, worth a read.

http://www.cambridgeaudio.com/assets/do ... _Paper.pdf

_________________
TTLS 17"
THT 24.5"
2x THT 16"
SLA LCR
Otop12 x2
Titan 48 24"


Sat Oct 20, 2012 6:26 pm
Profile
Site Admin
User avatar

Joined: Tue May 02, 2006 5:59 pm
Posts: 23488
Post Re: SLA / TLAH BMR drivers?
There's a lot of gobbledygook there, whereas the explanation is quite simple. Rather than using a cone shape to stiffen the diaphragm so that it doesn't flex it uses a flat honeycomb diaphragm. Being flat it doesn't suffer as much from phase issues as a cone, so high frequency dispersion is wider. The downside is that a honeycomb diaphragm has higher mass than a cone, so there's a loss of sensitivity, which grows worse exponentially as the diaphragm is made larger, so it only works well with smaller drivers. And it's more expensive to build than a cone driver, but if you can get them on closeout that's not an issue.


Sat Oct 20, 2012 6:56 pm
Profile

Joined: Sat Apr 21, 2012 9:17 pm
Posts: 62
Location: Adelaide, Australia
Post Re: SLA / TLAH BMR drivers?
Hmm, my plan so far is 6 drivers per cab wired to 12 ohm to stay within my budget with no tweets or crossover. The drivers have 81db sensitivity so with 6 I guess sensitivity will be high enough. Would there be any benefit building floor standing rectangular tlah's with 6 drivers rather than SLA's for mains?

_________________
TTLS 17"
THT 24.5"
2x THT 16"
SLA LCR
Otop12 x2
Titan 48 24"


Sat Oct 20, 2012 11:22 pm
Profile
User avatar

Joined: Mon Aug 14, 2006 5:08 am
Posts: 4539
Location: Punta Gorda, Florida
Post Re: SLA / TLAH BMR drivers?
Chompy191 wrote:
Hmm, my plan so far is 6 drivers per cab wired to 12 ohm to stay within my budget with no tweets or crossover. The drivers have 81db sensitivity so with 6 I guess sensitivity will be high enough. Would there be any benefit building floor standing rectangular tlah's with 6 drivers rather than SLA's for mains?


Could you somehow squeeze the 6 extra into your budget, to do 9 per TLAH? For an extra $40 or so, the results will amaze you.

_________________
Accept the fact that airtight and well-braced are more important than pretty on the inside.
If you can't find the time and money to do it right the first time, how will you find the time and money to do it right a second time?


Sun Oct 21, 2012 3:24 am
Profile

Joined: Sat Apr 21, 2012 9:17 pm
Posts: 62
Location: Adelaide, Australia
Post Re: SLA / TLAH BMR drivers?
An extra $90 for 6 more speakers with shipping expenses, but if the difference is that much then I might just go for it. Just still a bit unsure about sensitivity 81 db per driver, 6 driver sla and 9 driver tlah. Not too much difference in sensitivity between them? Should be all good with these BMR drivers for no tweeters. Otherwise I'm good to go.

_________________
TTLS 17"
THT 24.5"
2x THT 16"
SLA LCR
Otop12 x2
Titan 48 24"


Sun Oct 21, 2012 5:48 am
Profile
User avatar

Joined: Mon Aug 14, 2006 5:08 am
Posts: 4539
Location: Punta Gorda, Florida
Post Re: SLA / TLAH BMR drivers?
Chompy191 wrote:
An extra $90 for 6 more speakers with shipping expenses, but if the difference is that much then I might just go for it. Just still a bit unsure about sensitivity 81 db per driver, 6 driver sla and 9 driver tlah. Not too much difference in sensitivity between them? Should be all good with these BMR drivers for no tweeters. Otherwise I'm good to go.


:oops: My bad, I forget, more than sometimers, that not all on the forum are in the USA. :slap:

_________________
Accept the fact that airtight and well-braced are more important than pretty on the inside.
If you can't find the time and money to do it right the first time, how will you find the time and money to do it right a second time?


Sun Oct 21, 2012 11:42 am
Profile

Joined: Mon Oct 08, 2007 3:30 pm
Posts: 14
Location: Alabama
Post Re: SLA / TLAH BMR drivers?
Those look interesting. I'm currently trying to convince the war and finance department I gotta have these. Plans are for 2 SLA's and one curved SLA with 8 or 9 per cabinet. Thanks for the find.


Mon Oct 22, 2012 9:03 pm
Profile

Joined: Sat Apr 21, 2012 9:17 pm
Posts: 62
Location: Adelaide, Australia
Post Re: SLA / TLAH BMR drivers?
Good buy for anyone outside of the US. Ordered 20 and only cost $80 in shipping which is very good. Going 6 drivers per cab, probably all SLA since i'll be using these in my bedroom mainly. Not sure if it will be of any benefit building a curved centre due to the wide dispersion of these drivers. Will be making some small bookshelf speakers with the extra 2 for my pc so if anyone knows any good designs? and to practice finishing

_________________
TTLS 17"
THT 24.5"
2x THT 16"
SLA LCR
Otop12 x2
Titan 48 24"


Tue Oct 23, 2012 6:06 am
Profile
User avatar

Joined: Mon Aug 14, 2006 5:08 am
Posts: 4539
Location: Punta Gorda, Florida
Post Re: SLA / TLAH BMR drivers?
Chompy191 wrote:
Not sure if it will be of any benefit building a curved centre due to the wide dispersion of these drivers.


:confused: This makes no sense. The dispersion of this driver is no different than any other driver of the same size. Where are you getting dispersion figures? This driver will benefit from a curved center SLA.

_________________
Accept the fact that airtight and well-braced are more important than pretty on the inside.
If you can't find the time and money to do it right the first time, how will you find the time and money to do it right a second time?


Tue Oct 23, 2012 10:33 am
Profile
Site Admin
User avatar

Joined: Tue May 02, 2006 5:59 pm
Posts: 23488
Post Re: SLA / TLAH BMR drivers?
DJPhatman wrote:
:confused: This makes no sense. The dispersion of this driver is no different than any other driver of the same size.
Read my earlier post. :cop:
But the function of the CurveArray has nothing to do with the dispersion of the individual drivers employed.


Tue Oct 23, 2012 11:07 am
Profile
User avatar

Joined: Mon Aug 14, 2006 5:08 am
Posts: 4539
Location: Punta Gorda, Florida
Post Re: SLA / TLAH BMR drivers?
Bill Fitzmaurice wrote:
DJPhatman wrote:
:confused: This makes no sense. The dispersion of this driver is no different than any other driver of the same size.
Read my earlier post. :cop:
But the function of the CurveArray has nothing to do with the dispersion of the individual drivers employed.


So, how does the flat diaphragm, that is approximately 100mm in diameter, produce a 6000Hz sound wave that is ~57.17mm in length, let alone 12,000Hz which is ~2.85mm in length? This is the part that makes no sense to me.

_________________
Accept the fact that airtight and well-braced are more important than pretty on the inside.
If you can't find the time and money to do it right the first time, how will you find the time and money to do it right a second time?


Tue Oct 23, 2012 11:32 am
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 54 posts ]  Go to page 1, 2, 3, 4  Next

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

banner
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware for PTF.