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Can we discuss the BMR Tower?

Dennis Murphy

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Wouldn't any grill cause unwanted reflections off the grill edges?
Well, real men don't use grills. But those reflections are actually quite benign. They shift in mode depending on the off-axis angle and fill in with the reflected room sound. I have a bunch of measurements documenting this, and have conducted blind tests with the BMR grill on and off. But I think we can agree that most grills aren't improving matters.
 

phoenixdogfan

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Maybe Sonus Farber has a grille that would fit and could be sold separately. Then it would just be a matter of blue tacking a coupla six magnets to the front...and voila! A real beauty both visually and sonically.
 

Dennis Murphy

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Hi Dennis, do you have any measurements, info or at least comments concerning the tower’s vertical dispersion/frequency response?
I am assuming it is similar to the BMR since the bmr & raal drivers are the similar size and spaced so closely together.

I have them, but I'm always a little reluctant to post vertical plots because there's so little consensus as to what the target should be. Broad, even vertical dispersion? Deliberately restricted vertical dispersion? There's even less agreement on the merits of an MTM layout. All I can say is that the tower has a slightly cleaner, more focused sound in the lower treble than the BMR monitor. Maybe that has to do with the MTM radiation pattern. Maybe it's just that the crossover I used worked a little better. From a normal listening position, if you stand up there will be a more noticeable change in timber with the towers than with the monitor, although it's not a big difference. Up close, it will be quite noticeable. Hopefully no one will be using the towers as nearfield monitors.
 

thewas

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I have them, but I'm always a little reluctant to post vertical plots because there's so little consensus as to what the target should be. Broad, even vertical dispersion? Deliberately restricted vertical dispersion?
I don't think the question here is broad or narrow which depends a lot on personal preferences, room acoustics and listening distance but if a smooth directivity over the frequency band is achieved without the significant local deviations seen on most MTM configurations due to not fulfilling D'Appolitos requirements of driver spacing vs. crossover frequency.
 

restorer-john

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I have them, but I'm always a little reluctant to post vertical plots because there's so little consensus as to what the target should be. Broad, even vertical dispersion? Deliberately restricted vertical dispersion? There's even less agreement on the merits of an MTM layout.

The merits are very clear in my experience. That said, the MTM configuration is not a configuration that works if you like moving around your listening space while listening.
 

AdamG247

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alexis

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The three black MTM drivers made a contrast with the burl wood grain direction and color. I think if it is pure white (solid color without grain) or darker wood grain (or pure black), or horizontal wood grain vs. vertical, would make the top section look better. This is what it would look like in the exactly same burl veneer but being stained to dark brown.

I also think the natural burl tower looks much better in person vs. picture because of the top section driver contrast wasn't as strong in person.

IMG_2620.JPG
 

MarkS

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I can't believe so many care about the looks!

It looks fine! It's a speaker, and it looks like one.

My problem is that I find it hard to believe that those tiny little flat midrange drivers can move enough air, but I'm sure that impression is wrong … (and I hasten to add that I have never heard a BMR speaker, I'm just joining in the theme of "let's talk about how it looks")
 

jhaider

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I can't believe so many care about the looks!

You’re surprised people care about the looks of large objects to be prominently placed, often in the most public or high traffic areas of their homes? Especially when, as here, efforts have clearly been made to craft them as finely as possible?

I do think a single grille extending to slightly below the woofer would be an aesthetic improvement, but that’s just me. Sans grille is awkward just because the tweeter faceplate is so much wider than the mids. Ideal would be a bespoke metal faceplate for MTM (think Snell XA or similar) that only reveals driver diaphragms, but obviously that adds cost, likely considerable cost in a small quantity product.

Sonically, I would love to see this in @hardisj hands for one reason: the relatively high crossover between MTM and W. Question is whether there’s any potential stage height wandering here, as he found in the JBL HDI tower.
 
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blestin

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I actually kind of like it. In any event, it makes me think the top grill should be extended downward.

Please extend the top grill downward.
I have them, but I'm always a little reluctant to post vertical plots because there's so little consensus as to what the target should be. Broad, even vertical dispersion? Deliberately restricted vertical dispersion? There's even less agreement on the merits of an MTM layout. All I can say is that the tower has a slightly cleaner, more focused sound in the lower treble than the BMR monitor. Maybe that has to do with the MTM radiation pattern. Maybe it's just that the crossover I used worked a little better. From a normal listening position, if you stand up there will be a more noticeable change in timber with the towers than with the monitor, although it's not a big difference. Up close, it will be quite noticeable. Hopefully no one will be using the towers as nearfield monitors.

If I like to listen to music and “walk around” or work standing would you recommend I stay with my BMR monitor?
 

mtmpenn

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I am unfortunately not in the market for a floorstanding speaker, but I'll still give my worthless opinion on the grills...

My vote would be for a single rectangular grill that extends the full length of the cabinet. I think the simplicity would look nice. Also, I have small children and so I know that the port hole would end up getting stuffed with toy cars, legos, etc, if not hidden away.

You could also make the grill optional - that would provide an opportunity for an upcharge that would pay for the added packaging to reduce the chance of breaking.

Science?
 

Dennis Murphy

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I am unfortunately not in the market for a floorstanding speaker, but I'll still give my worthless opinion on the grills...

My vote would be for a single rectangular grill that extends the full length of the cabinet. I think the simplicity would look nice. Also, I have small children and so I know that the port hole would end up getting stuffed with toy cars, legos, etc, if not hidden away.

You could also make the grill optional - that would provide an opportunity for an upcharge that would pay for the added packaging to reduce the chance of breaking.

Science?
Right now our first priority is to avoid shipping damage, which was a problem with the first batch of towers despite what I thought were heroic efforts to protect the contents. I think we're going to have to keep the grills as is. We also don't want to strain relations with the cabinet factory. We've been a royal pain to them with our small orders and requests for finish options. They're used to churning out big hulking subwoofer black boxes in lots of 1,000. We have to keep things as simple as possible. which means that all of the cabinets will have magnetic inserts and grills included.
 

BluesDaddy

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I can't believe so many care about the looks!

It looks fine! It's a speaker, and it looks like one.

My problem is that I find it hard to believe that those tiny little flat midrange drivers can move enough air, but I'm sure that impression is wrong … (and I hasten to add that I have never heard a BMR speaker, I'm just joining in the theme of "let's talk about how it looks")
Which goes to show how wrong sighted bias can be.
 
D

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I wonder if we'll ever see a more budget oriented design around the BMR drivers. I'd very much like to hear what their dispersion is like, and while I did have the SB version of the BMR's ordered at one time, I had to cancel as I realized I was getting a little in over my head. A little complicated on the cabinetry.
 

Ericglo

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I wonder if we'll ever see a more budget oriented design around the BMR drivers. I'd very much like to hear what their dispersion is like, and while I did have the SB version of the BMR's ordered at one time, I had to cancel as I realized I was getting a little in over my head. A little complicated on the cabinetry.

You know you can buy a flat pack from Speaker Hardware.
 

Ericglo

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Second--and not addressed to you--I thought this was a science forum. All these comments about aesthetics make me think you guys thought you were posting on AVS. But since I have your attention, the grill design has proven as problematic as Middle East politics. A one-piece grill is prone to shipping damage and will cover a lot of the veneer. So far I haven't been able to come up with a 2-piece design that looks right. The first draft had an oval upper grill that along with the woofer grill looked like an exclamation point. So I got rid of the oval. It's still kind of klunky. Any suggestions are welcome. As for the "oddly spaced drivers," that's what you get when you optimize the woofer and port locations to maximize the quarter wave contribution, and squeeze the MTM configuration as close together as possible. It's called form following function, or more succinctly, science. :)


Hilarious:)

I don't think it would be to hard to make a DIY full size grill if that was what a customer wanted. If the customer didn't want to make it themselves, then I am sure one could find a carpenter or such to make it for them.

Personally with the wood grain I might lean more towards a grill. With a gloss black or white, I definitely would go without grills for a more modern look.

As for the leather, it would probably be a pain to cut out around the BMR drivers. If one was so inclined, then I would recommend going to Tandy Leather for supplies and advice.
 
D

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You know you can buy a flat pack from Speaker Hardware.

At nearly $400, the cost of the project just kind of kept going up and at the prices I was at, it was just smarter for me buy a premade speaker. There was also the chance that I wouldn't like them and I'd be stuck trying to sell a DIY speaker. I also didn't possess the tools to make the BMR driver cutout look up to my standards.

I'd like to see someone come up with a design that uses the BMR driver and woofer + tweeter for say, $500 a pair for the kit.
 

Kachda

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At nearly $400, the cost of the project just kind of kept going up and at the prices I was at, it was just smarter for me buy a premade speaker. There was also the chance that I wouldn't like them and I'd be stuck trying to sell a DIY speaker. I also didn't possess the tools to make the BMR driver cutout look up to my standards.

I'd like to see someone come up with a design that uses the BMR driver and woofer + tweeter for say, $500 a pair for the kit.
I think the components by themselves cost more than that
 
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