BMR Philharmonitor with Curved Cabinets

[TulseLuper]

Yup. Mostly I make furniture. Just finished a king size bed

Looks great, nice bed. I built an STR a few years ago out of solid birch with benchcrafted hardware. Best tool in the shop.

Back on topic, looks like the speakers will come out great. What’s the final baffle material? Is it painted black? Not sure if you’re familiar, but the MDF-like products GeoTone and Valchromat are dyed through and look great when inset like this baffle. The black color isn’t true black, but with a coat of oil gets to a very dark gray. Way easier than painting if you can tolerate the color and you want it matte.

 

[DeruDog]

Looks great, nice bed. I built an STR a few years ago out of solid birch with benchcrafted hardware. Best tool in the shop.

Back on topic, looks like the speakers will come out great. What’s the final baffle material? Is it painted black? Not sure if you’re familiar, but the MDF-like products GeoTone and Valchromat are dyed through and look great when inset like this baffle. The black color isn’t true black, but with a coat of oil gets to a very dark gray. Way easier than painting if you can tolerate the color and you want it matte.

I was just planning to spray it matte black. I've not done it before, so if that's problematic I may consider other options. I had planned to glue everything together in the cabinet and seal with caulk to be sure. So replacing the baffle at a later date will be onerous.

 

[DeruDog]

I’ve just assembled something similar, using two minidsp2x4, Hivi RT1.3, BMR and Dayton RS180p-4.
Fun project.

How did you wind up tuning the speakers? Did you use a UMIK and REW? Go outdoors to be as anechoic as possible, or just do it in room? I am considering whether it might be worth while to actively cross these over. I need some better amplification anyhow, so doing a 6-ch 240WPC is about the same as doing 3-ch 400WPC. Just concerned that setting the active crossovers might be a bridge too far, though I have used REW and a UMIK before for tuning a system. I got some feedback that the tuning of speaker drivers would be more complicated, though.

 

[DeruDog]

I have plans to build a set of curved BMR's and couldn't find anything on someone giving it a go until I found your post. Ive been working out designs similar to yours with the stacked sides and rod supports down the center. Im very interested to know how they turned out and how they sound. Any picture updates would be fantastic! good stuff man

Wound up not using through-rods and went with pegs instead (see above photo). If I had it to do over I would try out a more polyhedral inner profile with thick flat boards, and then create the round on a bandsaw. I think it would be a faster process in the end. This was certainly fun to design and I am excited to get back to assembling it. Just a few more CNC iterations and a lot of gluing and sanding.

 

[mightycicadalord]

In this application I am very impressed with the BMR. Large sweet spot and excellent dispersion. Makes the piano sound real, and female voice is stunning. Crossed at 900hz and 3500hz and have not experimented further.
The picture is one with red oak baffle. Still waiting for the curly maple.
When I built these, my intent was to see if I liked them and then perhaps build the real McCoy. However, these are so impressive in active mode, I may stick with them.......until something else comes along.

Curious what volume you went with for the BMR driver in your build.

 

[DeruDog]

Still working away. I have one baffle cut. Will finish up the first speaker before doing the other two. The crossovers are done too so I am ready to screw those in and wire them up.

 

[DeruDog]

One speaker done. Looks good and all drivers are working. Now to get to the next two.

 

[-Matt-]

Nice cabinet making skills.

Is it intentional that the tweeter is horizontal?

 

[mightycicadalord]

Tweeter?

 

[D!sco]

Yeah, tweeter? Explain?
(Nice cab)

 

[DeruDog]

Nice cabinet making skills.

Is it intentional that the tweeter is horizontal?

Yes. It’s the center channel so actually the speaker is on its side here. The other two will be vertical for left and right channels. This is how the designer recommends making a center channel.

 

[D!sco]

Yes. It’s the center channel so actually the speaker is on its side here. The other two will be vertical for left and right channels. This is how the designer recommends making a center channel.

That makes a lot of sense. I never think of placing a 3-way like that horizontally but it's probably really great swapping that wide dispersion around for theater, isn't it?

 

[ryanosaur]

That makes a lot of sense. I never think of placing a 3-way like that horizontally but it's probably really great swapping that wide dispersion around for theater, isn't it?

The BMR monitor does work very well with the Tweeter rotated. Since there is no duplication of drivers reproducing the band, you don’t get any lobing.
IIRC, there is some diffraction, but frankly I never noticed any change between having a vertical or horizontal orientation for the Speaker as a whole. I have used both: prefer vertical though.

 

[DeruDog]

The BMR monitor does work very well with the Tweeter rotated. Since there is no duplication of drivers reproducing the band, you don’t get any lobing.
IIRC, there is some diffraction, but frankly I never noticed any change between having a vertical or horizontal orientation for the Speaker as a whole. I have used both: prefer vertical though.

Thanks. I had assumed the only issue might be the baffle-step which is why I rounded the narrow side of the baffle as well, to match the long sides.

 

[DeruDog]

Update. Putting together the left and right cabinets.

 

[DeruDog]

 

[DeruDog]

View attachment 220050

All finished. I did Audyssey this morning and some listening in 2Ch with subs. Audyssey crossed them at 40 Hz and I upped that to 80 to match surrounds. They sound really great for music: Tidal through an Apple TV.
For TV I found that the center channel is almost distractingly clear. I will give it a few weeks but may turn that one down.
I did test them before setting them up using a stethoscope. No leaks that I found and all drivers running.
Before these I was running Boston Acoustics A series which were fine but the BMRs are noticeably better. So to my ear the ASR ratings were very helpful. Thanks Amir!

 

[mmi]

Nice work! I have considered a kit Phil BMR and this is another nice walkthrough resource. Thanks!