Even response
Hi Delphiplasma,
Thats a good result, well worth the effort.
It would be interesting to compare the upgraded passive crossover to an active crossover.
Do you happen to have a good midrange AV receiver handy to allow a comparison?
Try running the speakers in "Pure Direct mode" with the passive crossovers to get a good feel for the overall performance, maybe live with this set up for a few days.
Then bypass the passive crossovers and use the AV amp to run the BMR's and a second power amp (or integrated amp) using the line level sub out to run the bass.
You can set the crossove point on the fly, any point between 40Hz and 200Hz or maybe 300Hz depending on the AV amp.
Certain of the 2012 & 2013 Onkyo AV amps had very flexible DSP crossover for front speakers plus the sub out and bass management options.
Being an entry level design with a basic BMR and budget the resolution will be limited, but still should be enough to reveal some differences if you have the equipment available?
Cheers
Derek.
Hi Delphiplasma,
Thats a good result, well worth the effort.
It would be interesting to compare the upgraded passive crossover to an active crossover.
Do you happen to have a good midrange AV receiver handy to allow a comparison?
Try running the speakers in "Pure Direct mode" with the passive crossovers to get a good feel for the overall performance, maybe live with this set up for a few days.
Then bypass the passive crossovers and use the AV amp to run the BMR's and a second power amp (or integrated amp) using the line level sub out to run the bass.
You can set the crossove point on the fly, any point between 40Hz and 200Hz or maybe 300Hz depending on the AV amp.
Certain of the 2012 & 2013 Onkyo AV amps had very flexible DSP crossover for front speakers plus the sub out and bass management options.
Being an entry level design with a basic BMR and budget the resolution will be limited, but still should be enough to reveal some differences if you have the equipment available?
Cheers
Derek.
L-J,
For a commercial product, there's a whole host of related issues that you need to do some redefining of the end-use before looking at possible drivers.
For example, for serious 'fast bass' you would be looking towards a closed box design (infinite baffle, B2 alignment) that generally would require some freq boost at the lower register/octave (electronic Xover, if not DSP) that, in turn, requires the driver's capability to handle the extra power and so on, assuming a reasonable good quality of reproduction.
On the other hand, smaller drivers can sometimes give the 'fast bass' if well setup in Tuned Quarter Wave designs - not so easy tho, and then the driver lower efficiency raises it's head ...
For a commercial product, there's a whole host of related issues that you need to do some redefining of the end-use before looking at possible drivers.
For example, for serious 'fast bass' you would be looking towards a closed box design (infinite baffle, B2 alignment) that generally would require some freq boost at the lower register/octave (electronic Xover, if not DSP) that, in turn, requires the driver's capability to handle the extra power and so on, assuming a reasonable good quality of reproduction.
On the other hand, smaller drivers can sometimes give the 'fast bass' if well setup in Tuned Quarter Wave designs - not so easy tho, and then the driver lower efficiency raises it's head ...
Shallow bass drivers
I have used a few of these shallow bass drivers.....Very limited in SPL and poor sound quality....
The best way I have found to match the bass to the BMR's is to combine the following :
(1) Top quality Pro drivers with high power handling and linen surrounds....Anything with a rubber surround is fatally flawed.
(2) Active drive with good power amps.
(3) Powerful DSP to implement both crossovers and Eq.
(4) Matching driver loading, 0.707 Q for both bass and BMR drivers without driving the BMR's below Fb and without driving the bass drivers above Fb.
Cheers
Derek.
I have used a few of these shallow bass drivers.....Very limited in SPL and poor sound quality....
The best way I have found to match the bass to the BMR's is to combine the following :
(1) Top quality Pro drivers with high power handling and linen surrounds....Anything with a rubber surround is fatally flawed.
(2) Active drive with good power amps.
(3) Powerful DSP to implement both crossovers and Eq.
(4) Matching driver loading, 0.707 Q for both bass and BMR drivers without driving the BMR's below Fb and without driving the bass drivers above Fb.
Cheers
Derek.
Rubber Vs Linen
Hi Pnix,
Stored energy / energy dissipation ....All rubber / elastic stores and dissipates energy slowly, this results in the worst type of time domain distortion....Ghost echos.
Linen / cotton / silk is far superior when it comes to energy storage / dissipation.
The attached is more of a BMR Vs pistonic driver, but it also highlights the function of a driver surround, in my view rubber is the wrong choice.
All the best
Derek
Hi Pnix,
Stored energy / energy dissipation ....All rubber / elastic stores and dissipates energy slowly, this results in the worst type of time domain distortion....Ghost echos.
Linen / cotton / silk is far superior when it comes to energy storage / dissipation.
The attached is more of a BMR Vs pistonic driver, but it also highlights the function of a driver surround, in my view rubber is the wrong choice.
All the best
Derek
Hi Derek,
could you recommend any 10" or 12" drivers please,i'd probably use multiples,sealed & corner loaded.
Also,when will you be showing your speakers with the silk surround BMR's,i'm looking forward to seeing those.
Jason
Precision Devices & Beyma.
Hi Jason,
I like using remote subs.
Try varying the driver sizes as this helps spread the resonant frequency / room nodes in addition to multiple sub locations.
With remote subs the highest crossover you can then use is is 80Hz, this then means you will be limited in max SPL / dynamics when using single BMR's. You can still get great results, but just at low to medium volumes.
If you are seeking life like dynamics then you must increase the Sd....Line arrays are the best solution, esp if you design shallow cabinets for wall mounting....You gain low midrange output,kiss goodbye baffle step issues and have no rear wall reflections to worry about.
Given the choice wall mounting is a no-brainer compared to stand mounts / floor standers.
I dont know of any suitable 10 inch drivers, but here are some good 12 and 15 inch drivers.
PDN.12SB40
PD.1550
Beyma are slightly behind in performance and build quality but still offer great value for money.
I have attached a few docs of drivers I have used and really like, but I am sure you will get good results with most Pro drivers that drivers that conform to my suggestions a few posts ago.
Studio Au came round a few days ago to hear the silk surround BMR's.
I played a pair of single BMR's crossed over to 4 subs....A pair of experimental Seas 8 inch (Excel w22) used as subs / speaker stands(!) plus a 12 inch Beyma and a 15 inch Beyma.
I used a mid-range AV reciever (Yamaha) for all DSP / DAC's and room Eq.
Source was an Asus lap top with a SSD drive running windows 8 with JRiver.
USB out into a Meridian Explorer used to convert the USB into Toslink optical and fed into the Yamaha.
I also demo'd a 6 BMR driver mini array....I am sure Studio Au will tell you what he thought of the quality of the sound.....!
All the best
Derek.
Hi Jason,
I like using remote subs.
Try varying the driver sizes as this helps spread the resonant frequency / room nodes in addition to multiple sub locations.
With remote subs the highest crossover you can then use is is 80Hz, this then means you will be limited in max SPL / dynamics when using single BMR's. You can still get great results, but just at low to medium volumes.
If you are seeking life like dynamics then you must increase the Sd....Line arrays are the best solution, esp if you design shallow cabinets for wall mounting....You gain low midrange output,kiss goodbye baffle step issues and have no rear wall reflections to worry about.
Given the choice wall mounting is a no-brainer compared to stand mounts / floor standers.
I dont know of any suitable 10 inch drivers, but here are some good 12 and 15 inch drivers.
PDN.12SB40
PD.1550
Beyma are slightly behind in performance and build quality but still offer great value for money.
I have attached a few docs of drivers I have used and really like, but I am sure you will get good results with most Pro drivers that drivers that conform to my suggestions a few posts ago.
Studio Au came round a few days ago to hear the silk surround BMR's.
I played a pair of single BMR's crossed over to 4 subs....A pair of experimental Seas 8 inch (Excel w22) used as subs / speaker stands(!) plus a 12 inch Beyma and a 15 inch Beyma.
I used a mid-range AV reciever (Yamaha) for all DSP / DAC's and room Eq.
Source was an Asus lap top with a SSD drive running windows 8 with JRiver.
USB out into a Meridian Explorer used to convert the USB into Toslink optical and fed into the Yamaha.
I also demo'd a 6 BMR driver mini array....I am sure Studio Au will tell you what he thought of the quality of the sound.....!
All the best
Derek.
Regarding the DSP vs Passive discussion:
What does the audio world consider more offensive/less natural time.domain distortion?
Ringing or Pre-ringing?
I am of the opinion the latter is more objectionable
Which is more easily masked by room ambience, or the ear brain hearing mechanism?
I am of the opinion is it the former
What does the audio world consider more offensive/less natural time.domain distortion?
Ringing or Pre-ringing?
I am of the opinion the latter is more objectionable
Which is more easily masked by room ambience, or the ear brain hearing mechanism?
I am of the opinion is it the former
DSP Vs passive
Hi Mondo,
As this is a BMR thread I don't wish to drift OT.
There are active Vs passive crossover threads and also DSP filter ringing threads.....It might be better to re-post this on another thread?
For whats its worth, I am a fan of active DSP crossover /Eq and
skeptical about all passive crossovers.
Post Vs pre ringing.....You can eliminate one but its currently impossible to eliminate both.
Best options:
(1) Eliminate one and have higher levels of the other....Pick your poison, if I had to pick I would live with post ringing, but it is audible and gives a hard edge to high frequencies.
(2) Live with low levels of both..... I prefer this option as you can reduce the ringing to such low levels it is no longer audible, only measurable.
Cheers
Derek.
Hi Mondo,
As this is a BMR thread I don't wish to drift OT.
There are active Vs passive crossover threads and also DSP filter ringing threads.....It might be better to re-post this on another thread?
For whats its worth, I am a fan of active DSP crossover /Eq and
skeptical about all passive crossovers.
Post Vs pre ringing.....You can eliminate one but its currently impossible to eliminate both.
Best options:
(1) Eliminate one and have higher levels of the other....Pick your poison, if I had to pick I would live with post ringing, but it is audible and gives a hard edge to high frequencies.
(2) Live with low levels of both..... I prefer this option as you can reduce the ringing to such low levels it is no longer audible, only measurable.
Cheers
Derek.
My apologies, I saw the thread going in that direction so I didn't think i was posting OT.
I'm aware one but not both can be eliminated, and therein lay my point. DSP is a very useful and flexible tool, which I have very little knowledge of, except that it is not a panacea.
Passives have known and understood issues, and I recently became an advocate of the active filtering method. However, I have yet to 'hear' anything to persuade me to ditch analog active for DSP.
I guess it all depends how much correction you need to do. BMRs seems interesting, except that for me at least, starting with a driver with the smallest possible need for EQ is the best philosophy.
I'm aware one but not both can be eliminated, and therein lay my point. DSP is a very useful and flexible tool, which I have very little knowledge of, except that it is not a panacea.
Passives have known and understood issues, and I recently became an advocate of the active filtering method. However, I have yet to 'hear' anything to persuade me to ditch analog active for DSP.
I guess it all depends how much correction you need to do. BMRs seems interesting, except that for me at least, starting with a driver with the smallest possible need for EQ is the best philosophy.
Driver suitability for using with Eq....
No worries, just dont want to this specific BMR thread turned into another post / pre ringing filter thread!
This raises an interesting point on the type of drivers which benefit the most from using Eq and which drivers are least suited to using Eq.
A drivers full power response is the key measurement / performance metric which dictates a drivers suitability for Eq'ing.
Full power response is defined as the full radiation pattern of the combined horizontal and vertical radiation of the driver.
(1) The better a drivers power response the better the results will be when using Eq.
(2) When you Eq a driver, the cut / boost filter affects the full power response equally. Even if you are measuring and Eq'ing for best on axis performance, you will be cutting / boosting all the off axis angles by the same amount.
The two key advantages of a Bending Mode driver are its "speed" (low energy storage / fast energy decay) and its very broad and even power response.
When it comes to Eq'ing its the power response that is key.
A well designed 4.5 inch BMR has a superb power response, approx plus/ minus 70 degrees in both horizontal and vertical planes over a huge bandwidth of 60Hz to 15KHz....This makes it more suitable for Eq'ing than any other driver I have ever used.
Hope this helps and all the best
Derek.
No worries, just dont want to this specific BMR thread turned into another post / pre ringing filter thread!
This raises an interesting point on the type of drivers which benefit the most from using Eq and which drivers are least suited to using Eq.
A drivers full power response is the key measurement / performance metric which dictates a drivers suitability for Eq'ing.
Full power response is defined as the full radiation pattern of the combined horizontal and vertical radiation of the driver.
(1) The better a drivers power response the better the results will be when using Eq.
(2) When you Eq a driver, the cut / boost filter affects the full power response equally. Even if you are measuring and Eq'ing for best on axis performance, you will be cutting / boosting all the off axis angles by the same amount.
The two key advantages of a Bending Mode driver are its "speed" (low energy storage / fast energy decay) and its very broad and even power response.
When it comes to Eq'ing its the power response that is key.
A well designed 4.5 inch BMR has a superb power response, approx plus/ minus 70 degrees in both horizontal and vertical planes over a huge bandwidth of 60Hz to 15KHz....This makes it more suitable for Eq'ing than any other driver I have ever used.
Hope this helps and all the best
Derek.
Hi Derek,
Yeah i came up to your place last year,i heard your 16 driver line arrays & bought 8 BMR's from you !
I've had the cabinets ready for a while but been waiting to get the wiring soldered as i'm hopeless at soldering.
I can understand the benefit of the fabric surround bass drivers but the fs look high at 40hz & it also says they are designed for vented enclosures ?
Any chance you could post some pictures of the silk surround BMR's ? I could be tempted to make another trip up to hear those in action !
Cheers Derek
All the best
Jason
Fs is not a factor....
Sorry Jason....I remember you now!
I have just finished a new design with 6 BMR silk drivers crossed over at 200Hz to 12 rubber surround BMR's (6 either side) so each 6 by 3 panel has 18 BMR's, silk above 200Hz, rubber surround below 200Hz.
The end product is a very compact wall mountable 18 driver full range panel 545mm by 700mm by 150mm (WHD) that is good down to 40Hz.
Re subwoofers....Using DSP / active / sealed box...This completely frees you from the traditional TS parameters and (God forbid!) the dreaded port calculations...
Any of the Pro drivers I mentioned will all work beautifully as described..... You are welcome to come round and hear exactly how great they sound good (and how easy it is to build them).....
All the best
Derek.
Sorry Jason....I remember you now!
I have just finished a new design with 6 BMR silk drivers crossed over at 200Hz to 12 rubber surround BMR's (6 either side) so each 6 by 3 panel has 18 BMR's, silk above 200Hz, rubber surround below 200Hz.
The end product is a very compact wall mountable 18 driver full range panel 545mm by 700mm by 150mm (WHD) that is good down to 40Hz.
Re subwoofers....Using DSP / active / sealed box...This completely frees you from the traditional TS parameters and (God forbid!) the dreaded port calculations...
Any of the Pro drivers I mentioned will all work beautifully as described..... You are welcome to come round and hear exactly how great they sound good (and how easy it is to build them).....
All the best
Derek.
