Tectonic Elements have a new 3" BMR that looks really nice for 300Hz-20Khz...
New Tectonic Elements BMR® | Tectonic Elements
http://www.tectonicelements.com/wp-content/uploads/2014/05/TEL-DS-TEBM46C20N-4B-2.pdf
It's for sale in at Parts Express for $18. The normal UK supplier (RS Components) doesn't list it right now, so I've emailed Tectonic Elements to confirm if there is an active UK supplier.
Tectonic Elements TEBM46C20N-4B BMR 3" Full Range Speaker 4 Ohm
New Tectonic Elements BMR® | Tectonic Elements
http://www.tectonicelements.com/wp-content/uploads/2014/05/TEL-DS-TEBM46C20N-4B-2.pdf
It's for sale in at Parts Express for $18. The normal UK supplier (RS Components) doesn't list it right now, so I've emailed Tectonic Elements to confirm if there is an active UK supplier.
Tectonic Elements TEBM46C20N-4B BMR 3" Full Range Speaker 4 Ohm
Twin baffle for internal mounting
Hi Louis,
The rubber surround drivers are the same as the pair you have, the silk surround version has a lower profile (2mm) double roll surround so its easier to rear mount.
The best way to rear mount the BMR's is to use two baffles.
(1) Bolt the driver to a small birch ply or bamboo baffle approx. 132mm square and 10mm thick. The BMR must be flush mounted into this small inner baffle.
(2) Now bolt, or glue & screw, the inner baffle to the inside of the main cabinet baffle. The main cabinet baffle must not be any thicker than 10mm and must have a chamfered driver cut-out to allow for the BMR driver surround.
(3) The reason you must not have a thick front baffle is to avoid any wave guide effect which will start to reduce the power response of the BMR and introduce unwanted reflections.
Reduced dispersion is a bad thing.....
(The horn guys call it "controlled directivity" I call it "LCD" or Lowest Common Denominator where you shrink down the radiation pattern of the entire bandwidth of your driver to try and match worst beaming in the highest frequencies with the broader radiation of the lower frequencies....
Just imagine what a "megaphone" does to a piano....!)
Ideally your main baffle would be stranded bamboo as this is incredibly strong and non resonant even in 10mm thickness.
As an alternative to the above you get a custom alloy baffle CNC'd ....Say 5mm or 6mm thick alloy and make it chamfered so you can rear mount the driver to it and also stepped so it can be rear mounted to the main baffle so the and the top of the chamfer / driver surround is flush with the main baffle.
Looking forward to seeing your CG images of the above!
Cheers
D.
Hi Louis,
The rubber surround drivers are the same as the pair you have, the silk surround version has a lower profile (2mm) double roll surround so its easier to rear mount.
The best way to rear mount the BMR's is to use two baffles.
(1) Bolt the driver to a small birch ply or bamboo baffle approx. 132mm square and 10mm thick. The BMR must be flush mounted into this small inner baffle.
(2) Now bolt, or glue & screw, the inner baffle to the inside of the main cabinet baffle. The main cabinet baffle must not be any thicker than 10mm and must have a chamfered driver cut-out to allow for the BMR driver surround.
(3) The reason you must not have a thick front baffle is to avoid any wave guide effect which will start to reduce the power response of the BMR and introduce unwanted reflections.
Reduced dispersion is a bad thing.....
(The horn guys call it "controlled directivity" I call it "LCD" or Lowest Common Denominator where you shrink down the radiation pattern of the entire bandwidth of your driver to try and match worst beaming in the highest frequencies with the broader radiation of the lower frequencies....
Just imagine what a "megaphone" does to a piano....!)
Ideally your main baffle would be stranded bamboo as this is incredibly strong and non resonant even in 10mm thickness.
As an alternative to the above you get a custom alloy baffle CNC'd ....Say 5mm or 6mm thick alloy and make it chamfered so you can rear mount the driver to it and also stepped so it can be rear mounted to the main baffle so the and the top of the chamfer / driver surround is flush with the main baffle.
Looking forward to seeing your CG images of the above!
Cheers
D.
Nice cabinets
Hi Jason,
They look cool....Way better than lots of my prototypes!
They will need a good 24 hours of running full range with some punchy bass and percussion to loosen up the rubber surround and stiff suspension.
Loud enough to get a good plus / minus 1 mm cone movement.
If you reverse the polarity on one cabinet that will reduce the SPL if the volume is annoying the family.
Once run in try crossing them over around 80Hz.
Did I give you some solid core silver wire to wire then up?...That really helps the top end compared to stranded copper cable.
Looking forward to hearing your listening impressions.
Cheers
Derek.
Hi Jason,
They look cool....Way better than lots of my prototypes!
They will need a good 24 hours of running full range with some punchy bass and percussion to loosen up the rubber surround and stiff suspension.
Loud enough to get a good plus / minus 1 mm cone movement.
If you reverse the polarity on one cabinet that will reduce the SPL if the volume is annoying the family.
Once run in try crossing them over around 80Hz.
Did I give you some solid core silver wire to wire then up?...That really helps the top end compared to stranded copper cable.
Looking forward to hearing your listening impressions.
Cheers
Derek.
Thanks Derek,
I forgot to buy a bit of cable from you when I visited,I'm rubbish at soldering too,I was hoping they'd have press on connectors but they are tiny little solder on tabs.
I'm hoping to cross them over way higher than 80hz to totally relieve them of bass but I'll certainly play around with it,I currently cross my dipoles over to my woofers at 300hz with great results.
Thanks for the advice regarding running them in,I'll definitely do that,I wasn't sure if running in speakers was a myth but the woofers I'm currently using really came alive after a period of use to the point where it started to sound boomy & I had to run the room correction again.
I forgot to buy a bit of cable from you when I visited,I'm rubbish at soldering too,I was hoping they'd have press on connectors but they are tiny little solder on tabs.
I'm hoping to cross them over way higher than 80hz to totally relieve them of bass but I'll certainly play around with it,I currently cross my dipoles over to my woofers at 300hz with great results.
Thanks for the advice regarding running them in,I'll definitely do that,I wasn't sure if running in speakers was a myth but the woofers I'm currently using really came alive after a period of use to the point where it started to sound boomy & I had to run the room correction again.
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Hi BMR guys,
Although I have plans to build my first open baffle (3 way) speakers soon (because I like the OB concept), I also read something about the BMR drivers and also saw this nice informative thread.
Its a pitty that I cant hear the ones made by Derek, but I saw his Manger speakers that I know sound nice. So I trust Derek's ears.
I became enthousiastic about BMR's and I bought a used pair of BMR85DD N4Y drivers.
When I opened the package I saw that they have 2 pair of tiny solder on tabs. So they are Dual Voice Coil...?
Only the + tabs were soldered (?) by the previous owner. I will contact him too but I am veeerrrry curious how they sound and really want to try them tomorrow in a 2 way with a 16cm closed Scan Speak 18w8545k midbass (which I am not too fond off).
I have 2 questions;
- Does anyone now how to connect them best?
- you cant use them in OB right? Probably because of the wide radiation? Qts is high though.
By the way I have also always liked the line array concept and heard some good ones. So who knows maybe an Overkill Audio 8 or 16 someday?
Thanks in advance!
Don C.
Although I have plans to build my first open baffle (3 way) speakers soon (because I like the OB concept), I also read something about the BMR drivers and also saw this nice informative thread.
Its a pitty that I cant hear the ones made by Derek, but I saw his Manger speakers that I know sound nice. So I trust Derek's ears.
I became enthousiastic about BMR's and I bought a used pair of BMR85DD N4Y drivers.
When I opened the package I saw that they have 2 pair of tiny solder on tabs. So they are Dual Voice Coil...?
Only the + tabs were soldered (?) by the previous owner. I will contact him too but I am veeerrrry curious how they sound and really want to try them tomorrow in a 2 way with a 16cm closed Scan Speak 18w8545k midbass (which I am not too fond off).
I have 2 questions;
- Does anyone now how to connect them best?
- you cant use them in OB right? Probably because of the wide radiation? Qts is high though.
By the way I have also always liked the line array concept and heard some good ones. So who knows maybe an Overkill Audio 8 or 16 someday?
Thanks in advance!
Don C.
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Thanks Dyna and Derek,
So I connect them in series like in the second picture below?
Subwoofer Wiring Diagrams, One 4 ohm Dual Voice Coil (DVC) Speaker
Hopefully the previous owner was gentle with them. They look allright, Ill test them this week.
I was planning to make passive crossovers, and begin with a closed box.
I thought to use them completely fullrange in a closed box, using only the acoustic roll off. (And later to cross it with a ribbon tweeter).
But as I read your answer I think its better to cross like you mentioned but passive with 12dB or 6dB. (since its closed box).
A bit like in "the Rythem King". By the way there the crossover has some LCR circuits. And all the time I was hoping to use no xo at all... for the BMR.
Thanks for the silver wiring tip.
What is the BMR construction guide? To make them yourself?
Don C.
So I connect them in series like in the second picture below?
Subwoofer Wiring Diagrams, One 4 ohm Dual Voice Coil (DVC) Speaker
Hopefully the previous owner was gentle with them. They look allright, Ill test them this week.
I was planning to make passive crossovers, and begin with a closed box.
I thought to use them completely fullrange in a closed box, using only the acoustic roll off. (And later to cross it with a ribbon tweeter).
But as I read your answer I think its better to cross like you mentioned but passive with 12dB or 6dB. (since its closed box).
A bit like in "the Rythem King". By the way there the crossover has some LCR circuits. And all the time I was hoping to use no xo at all... for the BMR.
Thanks for the silver wiring tip.
What is the BMR construction guide? To make them yourself?
Don C.
Passive crossover is a waste of time...
Hi Don,
Any passive crossover is a waste of time with the BMR....The Rythem King proves this... Some of the best speaker designers around spent years wrestling with the design and the result....Not exactly well reviewed or a commercial or success!
Passive crossovers will destroy the raison d'etre of the BMR....
Too long a story to explain here but my strongest advice is if you can not build an active system (with DSP for the Eq) sell the BMR drivers and buy cones and domes or small full rangers and follow some of the excellent designs on this site.
Only by preserving the phase / time coherence of the BMR will you get the benefits. The best passive BMR's are done by Cambridge Audio and Naim (at very different price points!) and both can be beaten by well chosen traditional cones and domes / ribbons.
Only when you go active and use DSP will you release the full potential of any BMR....Then you can start down the road of finding the best BMR for your needs.
With your BMR's and existing equipment all you need to do is buy a year old / discontinued model from the Yamaha AV range for around £500 ( £1,000 to £1,500 new) and you will be able to build a system that will crush the Rythem King or anything near its price point.
What is your existing equipment / room / SPL requirements and what is your budget for the end game system?
Cheers
Derek.
Hi Don,
Any passive crossover is a waste of time with the BMR....The Rythem King proves this... Some of the best speaker designers around spent years wrestling with the design and the result....Not exactly well reviewed or a commercial or success!
Passive crossovers will destroy the raison d'etre of the BMR....
Too long a story to explain here but my strongest advice is if you can not build an active system (with DSP for the Eq) sell the BMR drivers and buy cones and domes or small full rangers and follow some of the excellent designs on this site.
Only by preserving the phase / time coherence of the BMR will you get the benefits. The best passive BMR's are done by Cambridge Audio and Naim (at very different price points!) and both can be beaten by well chosen traditional cones and domes / ribbons.
Only when you go active and use DSP will you release the full potential of any BMR....Then you can start down the road of finding the best BMR for your needs.
With your BMR's and existing equipment all you need to do is buy a year old / discontinued model from the Yamaha AV range for around £500 ( £1,000 to £1,500 new) and you will be able to build a system that will crush the Rythem King or anything near its price point.
What is your existing equipment / room / SPL requirements and what is your budget for the end game system?
Cheers
Derek.
Here is a copy of Derek's BMR guide, for those that may not have been emailed it.
Design suggestions for the CIA 4.5 inch Neo BMR
Design suggestions for the CIA 4.5 inch Neo BMR
Wow, that is a downer...
I thought the Rythem king and the NAIM's had pretty good reviews.
Well maybe I have to go Active. Also for OB I see most designs active, like Linkwitz LX521 and many others.
Its just that I myself havent heard a very 'musical' sounding digital dsp/eq/deqx system (yet).
I have heard Lingdorf roomcorrected setups and although it was good, smooth, and well balanced, for me I have always missed some "analog musicality with realness in instruments/vocals".
And thát is what I want in a setup.
I am not saying that passive sounds better. I have seldom heard a setup that I really liked completely. Even in the Top systems... there was allways something:
For example:
Wilson Maxx with Halcro; "electronically sounding"
Avalon ISIS with Spectral; impressive! but needed a bit more warmth.
I can go on with this.
On the other hand, some were really amazing:
Kharma Midi (in Kharma's company) with Lamm and Ongaku DAC; most emotion I have ever heard.
BML set, wow truly impressive.
Siltech Arabesque, Tannoy Westminister; very musical.
But of course the prices of these setups are absolute absurd, and I cant pay even a small fraction of it. So for me the fun is to build something with "cheap" drivers, that sound pretty good.
For the passive vs digital part I believe that those setups that missed something can be optimized with roomadjustments and finding the 'perfect' balance you like with components and cables.
And I am not sure if a digital dsp active set will bring me the sound that I love to hear.
Correct me if I am wrong.
But on the other hand if you dont want to spend a lot of money....., I think digital adjustments or filters will bring you definitly the best value for the buck. No doubt there.
I am sure my wish is almost impossible without spending a lot.
I use a DK Design VS1 Reference MKIII amp in a small dedicated listening room about 4x4 meter with room diffusors. So OB is a gamble, but I can place them 1 meter from the wall. SPL is not important and at this moment price is.
I use a Tangband w4-1320 fullrange now that I like, with a ribbon and bass. Thoughts are to get Manger SW and use it Open baffle (passive xo). Or your silk 16 BMR's in a closed box. Budget is limited though....
One note, I have no experience with an active xo yet, only heard some digital dsp'ed sets, also with deqx.
Thanks for the copy, Studio Au.
I thought the Rythem king and the NAIM's had pretty good reviews.
Well maybe I have to go Active. Also for OB I see most designs active, like Linkwitz LX521 and many others.
Its just that I myself havent heard a very 'musical' sounding digital dsp/eq/deqx system (yet).
I have heard Lingdorf roomcorrected setups and although it was good, smooth, and well balanced, for me I have always missed some "analog musicality with realness in instruments/vocals".
And thát is what I want in a setup.
I am not saying that passive sounds better. I have seldom heard a setup that I really liked completely. Even in the Top systems... there was allways something:
For example:
Wilson Maxx with Halcro; "electronically sounding"
Avalon ISIS with Spectral; impressive! but needed a bit more warmth.
I can go on with this.
On the other hand, some were really amazing:
Kharma Midi (in Kharma's company) with Lamm and Ongaku DAC; most emotion I have ever heard.
BML set, wow truly impressive.
Siltech Arabesque, Tannoy Westminister; very musical.
But of course the prices of these setups are absolute absurd, and I cant pay even a small fraction of it. So for me the fun is to build something with "cheap" drivers, that sound pretty good.
For the passive vs digital part I believe that those setups that missed something can be optimized with roomadjustments and finding the 'perfect' balance you like with components and cables.
And I am not sure if a digital dsp active set will bring me the sound that I love to hear.
Correct me if I am wrong.
But on the other hand if you dont want to spend a lot of money....., I think digital adjustments or filters will bring you definitly the best value for the buck. No doubt there.
I am sure my wish is almost impossible without spending a lot.
I use a DK Design VS1 Reference MKIII amp in a small dedicated listening room about 4x4 meter with room diffusors. So OB is a gamble, but I can place them 1 meter from the wall. SPL is not important and at this moment price is.
I use a Tangband w4-1320 fullrange now that I like, with a ribbon and bass. Thoughts are to get Manger SW and use it Open baffle (passive xo). Or your silk 16 BMR's in a closed box. Budget is limited though....
One note, I have no experience with an active xo yet, only heard some digital dsp'ed sets, also with deqx.
Thanks for the copy, Studio Au.
Hi Don,
You have clearly done a lot of R&D by listening to a wide range of high end systems and its great that you know what you like and what you don't like.
It may well be that you actually prefer an analogue / passive / valve and vinyl sound. If so you are in luck because a lot of this type of gear is available second hand at very low prices....Use Pay pal Ebay / Amazon and you can build a big buck system for a fraction of the cost with relative security.
If you are going to invest a sizeable chunk of cash into your system I would suggest spending £100 on a trip to the UK to hear what a killer DSP / BMR setup can do....Love it or hate it its the only way to be sure!
All the best
Derek.
You have clearly done a lot of R&D by listening to a wide range of high end systems and its great that you know what you like and what you don't like.
It may well be that you actually prefer an analogue / passive / valve and vinyl sound. If so you are in luck because a lot of this type of gear is available second hand at very low prices....Use Pay pal Ebay / Amazon and you can build a big buck system for a fraction of the cost with relative security.
If you are going to invest a sizeable chunk of cash into your system I would suggest spending £100 on a trip to the UK to hear what a killer DSP / BMR setup can do....Love it or hate it its the only way to be sure!
All the best
Derek.
Hi Derek,
Thanks for the invitation, I might do that around summer or so.
I am sure it will sound absolutely amazing!...
And you are probably right about what I prefer, allthough I think it is mix of both; analogue ánd correct(-ed) sound.
The right balance is the key for me, passive or digital, or a combo, thats what I will find out in my OB project this winter.
Ill let you know when I listened to the passive closed BMR
Good luck too.
Don C.
Thanks for the invitation, I might do that around summer or so.
I am sure it will sound absolutely amazing!...
And you are probably right about what I prefer, allthough I think it is mix of both; analogue ánd correct(-ed) sound.
The right balance is the key for me, passive or digital, or a combo, thats what I will find out in my OB project this winter.
Ill let you know when I listened to the passive closed BMR
Good luck too.
Don C.
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Pro recording studio
Hi Don,
You are welcome and good luck with your building!
Also, if you have a very good recording studio near you ( not home based studios) you might be able to get a demo of their main monitoring system.
Just offer them a few bottles of good wine or a crate of good beer and they will usually be happy to demo some good music!
Most studios use DAW's (Digital Audio Workstations) and some still have good analogue master tape machines, so if they can demo both you could do a blind test.
Turn your back on the mixing engineer / desk and ask them to randomly play a few test tracks / samples.....Good digital is awesome....its how most vinyl is recorded!!
Cheers
Derek.
Hi Don,
You are welcome and good luck with your building!
Also, if you have a very good recording studio near you ( not home based studios) you might be able to get a demo of their main monitoring system.
Just offer them a few bottles of good wine or a crate of good beer and they will usually be happy to demo some good music!
Most studios use DAW's (Digital Audio Workstations) and some still have good analogue master tape machines, so if they can demo both you could do a blind test.
Turn your back on the mixing engineer / desk and ask them to randomly play a few test tracks / samples.....Good digital is awesome....its how most vinyl is recorded!!
Cheers
Derek.