In my original post here I mentioned the question stems from having the fullrange on the top shelf in a small sealed cabinet and the bass unit on the bottom directly beneath. I’m finishing my amplifier with dsp boards and would like to be able to use my smaller electronics enclosure but for that I need to streamline the amount of boards to fit everything else. I also enjoy the sound of the w3.
For me the sub+ satellites in the Logitech style of multimedia is so boring, not engaging. Probably you'll get over with your double DSP with streaming.
Not my cup of tea
I,d rather have the 2" Sony's in bass reflex plastic thin boxes...not printed nor CnCed...
Casted...
Not my cup of tea
I,d rather have the 2" Sony's in bass reflex plastic thin boxes...not printed nor CnCed...
Casted...
I know y'all like technical debates and that's fine. I think it comes down to what your design goal is. I recently completed a WAW with a SEAS FU10RB and SB17NRX35. Having the upper mids and highs covered by one driver provides excellent imaging and cohesiveness. It's great as long as you're in the sweet spot. Concurrently working on a 2-way with the same woofer and an SB29 tweeter. It has a wider sweet spot and extended highs. Still sounds great but which one somebody prefers can be very subjective.
I’m just interested in opinions on having a 3’ spacing between the two units meeting around 300hz. Woofer on the floor, wideband on the shelf above it.
Why don't we see more (any?) small BMR drivers developed with high quality motors? All seem to be on the budget end developed for soundbars etc..
A 2.5" BMR could have high end dispersion nearly as good as most 1" dome tweeters and could cross as low as 500Hz given a couple millimetres linear travel. All that's lacking is really low distortion.
A 2.5" BMR could have high end dispersion nearly as good as most 1" dome tweeters and could cross as low as 500Hz given a couple millimetres linear travel. All that's lacking is really low distortion.
Have you seen Erins review of the tectonic bmr 2”? I like it a lot in the things I’ve used them in.
https://erinsaudiocorner.com/driveunits/tectonic-elements-tebm35c10-4-miniature-bmr-driver/
https://erinsaudiocorner.com/driveunits/tectonic-elements-tebm35c10-4-miniature-bmr-driver/
These were really nice in my shop until I pulled the bmr’s out and they got put on subwoofer duty in my living room. Actually the bass units that are on the floor below where whatever I decide is going to be the final mini bookshelf design. Anarchy 704 with Dayton reference series 8” pr tuned around 23hz in a half cube. Two of those are plenty for the townhouse.
Yes it's very impressive, for the price. I'd like to see what this design type could do when given a ScanSpeak level motor system, cast ali basket and possibly advanced simulation tools used to optimise diaphragm construction and suspension system.
I believe KEF drive their cones from the balanced model point, so in a way we might call them BMRs, ut they are not aiming at wide range drivers.
Considering that my amplifier boards are from Dayton, and even though I will be running a 15’ 1/8” line from the apple dac dongle, which is pretty decent, I’m not going to be spending a ton of time trying to be critically listening to high end recordings. I probably should consider reinstalling the bmr’s in my cabinets and put them on my middle shelf and situate them so the bmr on the right is less obstructed by the loveseat back cushion. Wasn’t really an option with the w3’s because they need to be right on axis but with the bmr’s dispersion they could probably be toed out and work fine.
Would be very doable for me to fabricate the bmr mounting baffles in a way that points them more on axis while keeping the bookshelves square and sitting nicely. The cabinets are actually an almost tight fit and with the pr on the back I have to keep in mind it’s excursion when romping down low. There isn’t enough room under the grills to make the w3’s on axis like that.
The distortion is pretty decent on the bmr’s and considering I never would ask more than the 90db plot it might just be alright. I can’t hear sparkle anymore anyway. This is good friends 🥂 Just under the 1/4 c to c goal and a much simpler setup.
The two drivers for comparison
Bmr
W3
Would be very doable for me to fabricate the bmr mounting baffles in a way that points them more on axis while keeping the bookshelves square and sitting nicely. The cabinets are actually an almost tight fit and with the pr on the back I have to keep in mind it’s excursion when romping down low. There isn’t enough room under the grills to make the w3’s on axis like that.
The distortion is pretty decent on the bmr’s and considering I never would ask more than the 90db plot it might just be alright. I can’t hear sparkle anymore anyway. This is good friends 🥂 Just under the 1/4 c to c goal and a much simpler setup.
The two drivers for comparison
Bmr
W3
Attachments
good for a line array?
https://www.parts-express.com/Tectonic-TEBM35C10-4-BMR-2-Full-Range-Speaker-4-Ohm-297-216?quantity=1
$6.70 each and this is before quoting "large quantity"
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Consensus is that frequencies below 200Hz are not perceived as localized by the average listener. Above that point may introduce issues. I don't claim to have "golden ears" but I prefer to keep bass units close to the mains above 100Hz. I seem to notice the source if it's higher than that.
That’s interesting, I always thought height perception began somewhere above 1khz ad the wavelengths in relation to the size of the ears are way longer. It’s been a while since I was digging deep on diyma but I feel like the only reason ~1khz seems to it’s the start of height perception is that having a woofer low playing up to that point has harmonics that are in the wavelengths that the shape of the ear can become useful in deciphering the information from the outer ear shape. That’s not my saying I know, just how I imagined it working.
It’s the lobing that I wonder about as that is most of the driver spacing discussion content. I certainly can’t hear the woofer playing low, not in any properly tuned cars and not in the little bit of playing around with this particular system as it comes together. I understand that sometimes we don’t know something is happening acoustically until it’s pointed out and after that it’s clear as day. I wonder if lobing in the midbass would be noticeable behind a curtain.
It’s the lobing that I wonder about as that is most of the driver spacing discussion content. I certainly can’t hear the woofer playing low, not in any properly tuned cars and not in the little bit of playing around with this particular system as it comes together. I understand that sometimes we don’t know something is happening acoustically until it’s pointed out and after that it’s clear as day. I wonder if lobing in the midbass would be noticeable behind a curtain.
On the other side of the spectrum, I begin to wonder the audibly of lobing if crossing to a tweeter as we get higher and higher. At first I didn’t think this was the right thread for that but then I remembered that people put a tweeter to assist a large wideband driver that can’t quite get up as high as needed. It surely is lobing in that situation.
Wideband drivers that rely on the summing of resonances to get a reasonable response cannot deliver high quality performance in a technical sense. To get the uneven +/- 5 dB response shown will have required considerable engineering and simulation effort to get the resonances to sum and cancel in an optimum manner. Likely more than an expensive Scan-Speaker driver in the same way that optimizing the design details of a small ported 2 way to perform well requires more simulation and engineering effort than getting a 3 or 4 way to deliver higher performance.
It makes no engineering sense to use an expensive motor with a strongly resonant bending wave driver. It might make business sense if one can get the marketing right for a low volume audiophile speaker where value for money in terms of delivered technical performance is unimportant. The Tectonic driver came out of the big push in the 90s to deliver cheap to manufacturer but fairly expensive to design bending wave drivers (requiring high volumes to make business sense) for budget consumer and budget side surround speakers. It made sense at a few pounds per driver but it didn't really catch on although products like this are still on the market.
Over late last year I read through this thread in chewable pieces and have begun to re-skim through it when I can to refresh myself of the valid points on both sides. I see where a wideband and bass driver won’t deliver the technical prowess of the korean army marching, and that wideband lacks some things like blistering transient speed above where I can’t even hear any more, wide consistent dispersion,
Crossovers used to rattle my chain over phase, so I began to run three ways and chose filters and outside of the general 300-3000 range. Later I come to understand the FM curve and that the phone curve is up to 6k and lobing can be throwing off the power response and consistency of vertical reflections. Now we have to put all this effort into choosing the best compromise tweet/mid spacing and also a very specific xover point that complexly involves more things.
In the non-expert diy setting, who can provide the resources of time and money into optimizing the placement of a tweeter? I got these 1” SS rings off diyma nib for $200 and quickly snatched them up to add to my RS100 in mini knock down cabinets. I don’t have the measurement equipment, and if I do I won’t be able to learn those functions in rew until maybe my slow period in January-February. I actually do own a lawncare company.
So I managed to squeeze out these cabinets in a lightly buffed flat black they sound cool in roughly playing with them.
But now I have to figure out how best to tune them. I’m not prepared to plop an optimized low order xover right in the middle of the vocal meat. So then I think I should just push it up to 4khz where the problems will be much less noticeable. Well, chit, now I have ss illuminator tweeters that I’m pushing further and further up and out of where their quality even matters. 3khz is 4.5”, my c to c is 3.5”, 1/4 wave is 1.125”. So even with a 1” tweeter almost kissing a mid with a 3.7” diameter, we still have to just get in all cozy with the center point of the human voice.
Or, I can run a small fullrange that is universally accepted as very pleasant to listen to and provides a cohesiveness that is difficult to pin down exactly why, but is present. So the blistering transients and lack of rocking modes and such of the ring radiator are missing, I guess, but the overall musical enjoyment of the w3 is eerily there for some reason in spite of the lack of scoring all ten’s on the list of technicalities. I’m sure Steely Dan’s engineers didn’t use fast monitors but small bass assisted fullrangers seem to be overall taken as very pleasant to enjoy. Considering that at high frequencies the fullrange cone is only really vibrating near the dust cap, the mass should be fairly low anyway. So now do I fret about my two ways casting lobes into the room, or choose a paper fullrange that is mostly well behaved up towards the top octave?
Crossovers used to rattle my chain over phase, so I began to run three ways and chose filters and outside of the general 300-3000 range. Later I come to understand the FM curve and that the phone curve is up to 6k and lobing can be throwing off the power response and consistency of vertical reflections. Now we have to put all this effort into choosing the best compromise tweet/mid spacing and also a very specific xover point that complexly involves more things.
In the non-expert diy setting, who can provide the resources of time and money into optimizing the placement of a tweeter? I got these 1” SS rings off diyma nib for $200 and quickly snatched them up to add to my RS100 in mini knock down cabinets. I don’t have the measurement equipment, and if I do I won’t be able to learn those functions in rew until maybe my slow period in January-February. I actually do own a lawncare company.
So I managed to squeeze out these cabinets in a lightly buffed flat black they sound cool in roughly playing with them.
But now I have to figure out how best to tune them. I’m not prepared to plop an optimized low order xover right in the middle of the vocal meat. So then I think I should just push it up to 4khz where the problems will be much less noticeable. Well, chit, now I have ss illuminator tweeters that I’m pushing further and further up and out of where their quality even matters. 3khz is 4.5”, my c to c is 3.5”, 1/4 wave is 1.125”. So even with a 1” tweeter almost kissing a mid with a 3.7” diameter, we still have to just get in all cozy with the center point of the human voice.
Or, I can run a small fullrange that is universally accepted as very pleasant to listen to and provides a cohesiveness that is difficult to pin down exactly why, but is present. So the blistering transients and lack of rocking modes and such of the ring radiator are missing, I guess, but the overall musical enjoyment of the w3 is eerily there for some reason in spite of the lack of scoring all ten’s on the list of technicalities. I’m sure Steely Dan’s engineers didn’t use fast monitors but small bass assisted fullrangers seem to be overall taken as very pleasant to enjoy. Considering that at high frequencies the fullrange cone is only really vibrating near the dust cap, the mass should be fairly low anyway. So now do I fret about my two ways casting lobes into the room, or choose a paper fullrange that is mostly well behaved up towards the top octave?
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I would be really interested to hear the technical faults of the bmr 2” though. I read Toole mentioning group delay being present but have yet to find any real details on how it’s manifesting. They too are pleasant to listen to but I see the odd looking response above 5khz and wonder if energy is being stored and if that’s where the group delay is. But again, it’s all basically out of the telephone band so I don’t know how detrimental it actually is. The distortion is low enough for me and while I want to use the tang w3’s, I can’t help but wonder how badly the bmr is butchering the music.
It is a driver designed and manufactured for budget consumer audio devices (large market). It is low cost, low output/power, wide frequency range excluding low frequencies +/- 5 dB or so (which might be addressed with DSP if that is part of the audio consumer device) and with a wide and even polar response which distinguishes it from many other budget wideband 2" drivers. It seems to be a competitive product in it's intended market.
Not sure it has technical faults when it comes to high fidelity it's more that it isn't appropriate because it uses resonances to get output at higher frequencies. This is fine for budget audio speakers but not for expensive ones requiring a high technical performance. It does seem to have a presence though in audiophile speakers where a high technical performance in the studio monitor sense is less important and the wide dispersion and characterful response may create something attractive. For example this consultant has used it in a range of designs he has been involved with.
Not sure it has technical faults when it comes to high fidelity it's more that it isn't appropriate because it uses resonances to get output at higher frequencies. This is fine for budget audio speakers but not for expensive ones requiring a high technical performance. It does seem to have a presence though in audiophile speakers where a high technical performance in the studio monitor sense is less important and the wide dispersion and characterful response may create something attractive. For example this consultant has used it in a range of designs he has been involved with.
BMR (balanced mode radiator = DML (distributed mode), last the originalname.
These work by having a set of resonances that sum together to create an approximately flat FR.
The company that invented them spent a huge amount developing and promoting them, didn’t get many licences and went backrupt dhortly after the patent expired.
A zillion AES papers on them.
Execution is important, they do have the potential to do a decent job, and we need to be remonded that above a certain frequency a FR driver does something somewhat related.
dave
These work by having a set of resonances that sum together to create an approximately flat FR.
The company that invented them spent a huge amount developing and promoting them, didn’t get many licences and went backrupt dhortly after the patent expired.
A zillion AES papers on them.
Execution is important, they do have the potential to do a decent job, and we need to be remonded that above a certain frequency a FR driver does something somewhat related.
dave