Here is my current first concept for a speaker using a BMR 4.5" Neo Full range driver, 200Hz +
And a 10" driver as woofer. I currently have these running in simple MDF cabinets, but am looking to make a showpiece and something really special.
Birch plywood CNC cut frame. The rest solid wood. Currently thinking of making it in facets with a Birds Mouth router cutter, and planing into a smooth shape, inside would stay faceted, with no parallel faces.
And a 10" driver as woofer. I currently have these running in simple MDF cabinets, but am looking to make a showpiece and something really special.
Birch plywood CNC cut frame. The rest solid wood. Currently thinking of making it in facets with a Birds Mouth router cutter, and planing into a smooth shape, inside would stay faceted, with no parallel faces.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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Without making the thing monolithic, how best to address the centre to centre spacing?
Smaller driver close, wider cabinet (if kept its tapered shape would end up huge) side firing? Lower XO?
Smaller driver close, wider cabinet (if kept its tapered shape would end up huge) side firing? Lower XO?
centre to centre spacing options
Hi Louis,
Try using two ( or 3!) 8 inch drivers positioned vertically, they will work better aesthetically and sonically....
Cheers
Derek.
Hi Louis,
Try using two ( or 3!) 8 inch drivers positioned vertically, they will work better aesthetically and sonically....
Cheers
Derek.
This was the 'inspiration' for the bass cabinet, toe in full range idea...
If using active XO, wonder how it would work having a few BMR's running down the length, with a 10" for 100Hz and under? Say with 3 in the bass cabinet with different cabinet volumes and crossovers at 200 - 300 - and the one on top running from 500Hz+. In essence a mini Line array with sub.
Reluctant to stick an extra 8" Mid in along with the 10", but perhaps a 8" covering the low end. Keen to try the Geddes/Swarm approach with multiple subs, so a good 8" driver should cover the last few octaves with a few subs covering 80-100Hz and down?
Aesthetics are defiantly important, especially with concept designs...
If using active XO, wonder how it would work having a few BMR's running down the length, with a 10" for 100Hz and under? Say with 3 in the bass cabinet with different cabinet volumes and crossovers at 200 - 300 - and the one on top running from 500Hz+. In essence a mini Line array with sub.
Reluctant to stick an extra 8" Mid in along with the 10", but perhaps a 8" covering the low end. Keen to try the Geddes/Swarm approach with multiple subs, so a good 8" driver should cover the last few octaves with a few subs covering 80-100Hz and down?
Aesthetics are defiantly important, especially with concept designs...
R&D....
The BMR's break all the rules so you cant sim them effectively and all the old timers on the DIY sites who have had "over 50 years building speakers....!" will tell you the don't work....Ignore those guys!
The only way to be sure how it will sound is to build it....!
The attached crossed over between 200Hz and 400Hz.
Try sketching a curved vertical stack cabinet based on my old Encore bass design, but make it slimmer... approx. 230mm flat front curving out to approx. 345mm at the widest, then tapering back to flat rear approx. 100mm wide. Total depth can be varied to suit internal volume requirements of whatever drivers you use.
I would not advise putting in any extra crossovers above 200 Hz...The reason'dtre of the BMR is crossover free....!!
Cheers
Derek.
The BMR's break all the rules so you cant sim them effectively and all the old timers on the DIY sites who have had "over 50 years building speakers....!" will tell you the don't work....Ignore those guys!
The only way to be sure how it will sound is to build it....!
The attached crossed over between 200Hz and 400Hz.
Try sketching a curved vertical stack cabinet based on my old Encore bass design, but make it slimmer... approx. 230mm flat front curving out to approx. 345mm at the widest, then tapering back to flat rear approx. 100mm wide. Total depth can be varied to suit internal volume requirements of whatever drivers you use.
I would not advise putting in any extra crossovers above 200 Hz...The reason'dtre of the BMR is crossover free....!!
Cheers
Derek.
solid wood housing for BMR
With your cabinet skills you could make a cool solid wood housing for the BMR....A custom sorbothane pad is the best way to enable correct driver positioning with secure mounting, totally vibration free and cool asthetics.
I think three 8 inch bass drivers below it will be great!
Cheers
D.
With your cabinet skills you could make a cool solid wood housing for the BMR....A custom sorbothane pad is the best way to enable correct driver positioning with secure mounting, totally vibration free and cool asthetics.
I think three 8 inch bass drivers below it will be great!
Cheers
D.
So many people take great steps to isolate the mid/hi frequency drivers from the bass, wondering if a completely separate bass assembly, say with two speakers covering 150Hz up, but with 4 discrete small subs sat in an arc around them. Could be close but not attached, would the same vibrations I would be trying to avoid simply run through the floor?
Not sure wifey would approve.....
An externally hosted image should be here but it was not working when we last tested it.
Distributed subs are great, but expensive....Need to be crossed over at 60Hz max for critical two channel ( 80 Hz for THX home cinema) music.
Each sub needs to be very heavy and well built and making sups look pretty is expensive....Then you have to provide each sub with a high quality 300 to 500 watts....Plus Eq...
In performance terms the best value for money would be the three 8 inch bass drivers plus separate BMR head unit. The Sorbothane pad will totally isolate the BMR from bass resonance.
In order to achieve the best bass performance, you will need to ensure your bass cabinet has approx. 1,000 times the combined Mms of the bass drivers ....
So assuming approx. 25g Mms per 8 inch bass driver you will need a 75Kg bass cabinet....Anything lighter will " rock and roll" to some extent....
" For every action there is an opposite and equal reaction..."
So, to go to extreme example, if you had a light weight cardboard bass cabinet, every time the 660 cm square Sd of the bass drivers shoots forward to send you a clean transient, the cabinet would "rock" backwards....Blurry bass, no impact, to detail etc...
This is a separate issue from the delayed energy storage / release characteristics that all cabinets have to some extent...
I think your cabinet skills are the key to your success...Make killer cabinets, use good drivers and DSP crossovers and you will do well!
Good luck
Derek.
Each sub needs to be very heavy and well built and making sups look pretty is expensive....Then you have to provide each sub with a high quality 300 to 500 watts....Plus Eq...
In performance terms the best value for money would be the three 8 inch bass drivers plus separate BMR head unit. The Sorbothane pad will totally isolate the BMR from bass resonance.
In order to achieve the best bass performance, you will need to ensure your bass cabinet has approx. 1,000 times the combined Mms of the bass drivers ....
So assuming approx. 25g Mms per 8 inch bass driver you will need a 75Kg bass cabinet....Anything lighter will " rock and roll" to some extent....
" For every action there is an opposite and equal reaction..."
So, to go to extreme example, if you had a light weight cardboard bass cabinet, every time the 660 cm square Sd of the bass drivers shoots forward to send you a clean transient, the cabinet would "rock" backwards....Blurry bass, no impact, to detail etc...
This is a separate issue from the delayed energy storage / release characteristics that all cabinets have to some extent...
I think your cabinet skills are the key to your success...Make killer cabinets, use good drivers and DSP crossovers and you will do well!
Good luck
Derek.
Still get the same error message, but was able to open them in Firefox, so apparently it's a Google problem ['big brother' censorship?]
GM
Well, I've got over 50 yrs experience and don't know enough about this one to come to any such conclusion, so take exception to your all inclusive damnation. Please point us to complete specs, response, polar, impedance plots of this particular BMR driver. I'm having no luck with Google with either BMR as a brand, model or even as a 4.5".
GM
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