Philharmonic BMR Speaker Kit - A Few Build Notes

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WoodBurner

Member
Joined 2021
#1
I just finished the Philharmonic BMR speaker kit (the bookshelf version) from Meniscus Audio and thought I would capture a few notes in case it is helpful to someone else building or thinking about building it. I built the cabinets, although flatpacks are available for this kit.
  • The biggest challenge in the baffle is that the BMR driver is not round. It has projections for the screws, and so the usual approach with routing using a Jasper circle jig is not adequate. After searching for ideas, I covered a BMR with plastic, screwed it face down on a piece of ¼ plywood, and used a router template kit I had to make a template for the driver. The template kit is designed to compensate for the router bit width when you create and then use the template. Once I had the template, I routed the hole for the body of the driver in the baffle, carefully placed my template on the baffle so it was oriented evenly over the hole and square to the baffle, clamped it down and then routed out those screw projections. As you can see from the picture, it produced a nice, tight fit. As an only moderately skilled woodworker, I was very happy with the results.
  • Within the cabinet, there is a small box for the BMR – kind of a cabinet within the cabinet. I had trouble visualizing this from the drawings, but found a video of a flatpack being assembled and that made it clear.
  • The inside box for the BMR needs to go right up against the brace – the brace forms one of the walls. I cut slots on the side walls of the cabinet for the brace with multiple passes on the table saw. I made the first pass at the same height as the top of the cutout, then made subsequent cuts until the brace fit into the slots.
  • Routing the irregular shape for the BMR, and getting the inside BMR box in the right place were the only aspects that made this a more challenging build than other speakers I have built. (I have done a few, not a lot).
  • From other posts, including from Dennis Murphy – the designer of the BMR - I made sure the little BMR box was very well sealed, including the hole for the wires, and stuffed that little box very full of eco-core. Much more stuffed than I would have had I not seen his posts.
  • I did not do the fancier joinery which came with the plans. My panels were all straight cuts which I joined with my Festool Domino.
  • I made the woofer crossover layout to look like the pictures of the built crossovers Meniscus has on their site. They are a little different from the orientation in the drawings that come with the kit. If I didn’t do this, the woofers were longer than the inside width which would make placing them a good distance from both the mid crossover and the woofer driver a challenge.
  • The overview is that the sound stage is large, and I am hearing things I’ve never heard before in songs I have been listening to for a long time. So far, nothing has been disappointing, and I have had multiple moments of sheer joy hearing new things.
  • Some song-specific impressions:
  • All For You – Sister Hazel – (live version) – The width of the sound stage helped with the “you are there” feeling as the crowd responds to the intro. With a compressed sound stage the two singers can feel on top of each other, but they help distinctly separate spaces.
  • I haven’t Been Me – Once Blue – I had never heard her breaths before. So cool.
  • Rich Mullins – Sometimes By Step – This is a poor recording which I expected to sound poor because these speakers are revealing. It didn’t, it sounded great. The intro to this song is some moderately fast piano playing. What I had never heard before is that the drummer is hitting his high hat in synch with those notes. Listened to this song a hundred times and never heard that before.
  • I’ll take you There – Sapphires – Heard ghost notes from the drummer I had not heard before. It is a much more complex beat he is doing that I ever realized. I enjoyed the song much more hearing that.
  • Quanta Qualia – Hayley Westenra – I love this song. It is beautiful. And it’s a good tweeter test as she hits outrageously high notes and I have heard it sound a bit shrill on lesser speakers. No shrillness at all. In addition, my wife remarked that there were a pair of voices in one place where she thought it was single before. In general, as she is singing notes of accompanying instruments, it was much easier to hear to them both separately.
  • Songs by Chicago also sounded better than I expected – great music not very well recorded.
  • I love these speakers. They sound great to me and I am anxious to finish work each day so I can go downstairs and listen to more music.
My setup
  • Raspberry Pi with a Digi SPDIF HAT feeding digital flac into a Topping E30 DAC.
  • Dac into an SP14 tube preamp.
  • From the SP14 into 2 down-firing Rythmik Audio DS1200 subs.
  • And into M-125 tube monoblocks. And out to the wonderful BMR bookshelf speakers.
    Speakers.jpg
    BMR.jpg
 
#7
Thanks for this write-up. I've been interested in building a pair of BMR's. The first speaker I ever built was Dennis Murphy's MBOW-1. It was such a great sounding small pair of speakers. I wound up building three pairs and giving them away to friends. I'm sad I no longer have a pair. The second model speaker I speaker built was the Ellis Audio 1801B - crossover designed by Dennis Murphy. Also a great sounding speaker, which I never gave away. I'd love to get a chance to hear the BMR at some point.
 
#8
aljordan said:
Thanks for this write-up. I've been interested in building a pair of BMR's. The first speaker I ever built was Dennis Murphy's MBOW-1. It was such a great sounding small pair of speakers. I wound up building three pairs and giving them away to friends. I'm sad I no longer have a pair. The second model speaker I speaker built was the Ellis Audio 1801B - crossover designed by Dennis Murphy. Also a great sounding speaker, which I never gave away. I'd love to get a chance to hear the BMR at some point.
Click to expand...
I know from reading other threads that Dennis has done road shows in the past with the BMR - I don't know if he does that any more. As ODougBo mentioned, he brought them to a show in DC recently and may being doing more. I agree about Dennis, his speakers sound great. After the BMRs I put together the new Affordable Accuracy - counts as DIY about as much as installing a changing a doorknob, but just listening to them now in my office and I do love the way he voices his speakers.
 
#13
DM = Dennis Murphy. I believe the history is he designed and sold the speakers (not as kits). He closed his original business, then reopened (Philharmonic Audio) where he once again is selling the BMR and other speakers. At some point he made the design of the BMR bookshelf available as part of a kit from Meniscus Audio. The design which comes with the kit explicitly says "Proprietary and Confidential" on it. Wolf_Teeth is absolutely correct.
 
#16
R&D : my foot. You pick three drivers from the shelve, measure them as per VCad @5 degrees intervals , and throw the .frd and .zma files in VCad.
What Jack Oclee-Brown has done at KEF is R&D, what Mark Dodd at Celestion does is R&D, what Lars Risbo does in designing the Purify drivers is R&D. Even the Linkwitz designs are R&D based in my book.
It is nothing more than a well designed 3 way system -around a unusual wideband midrange- with existing drivers is not R&D. Full Stop. Feel free to make money that way, thats fine with me.
 
#17
You still have to apply the knowledge of what works best with certain drivers in the application at hand. Yes- they are off the shelf drivers, but that does not matter here, let alone this design in particular. There is still a ton of empirically found results. I could have called it 'work product' instead. You'd still come off like what we xover designers do is not considered high level or great-results enough to then be considered good enough. I think well-done result driven designs actually warrant being intellectual property and owned by the designer that has his name on them and selling to the public.

To own an applied xover/speaker design is not a silly thing, as a lot work goes into them. You saying it does not matter that someone worked on it to get the performance contained, and that the 'copyright', 'confidentiality', or 'free for non commercial use', or whatever stipulation is nonsense is no different than selling actual Gucci or Rolex items with your name on it.
 
#19
I don't want to wander into the debate but I have noticed that just because one uses an advanced simulator, doesn't mean they get especially good results. For many, that's probably neither here nor there.. but between us it takes someone who knows how to make a good crossover without advanced tools to be able to make one with them.
 
#20
Woodburner,

Wonderful work on the BMR loudspeakers. Especially the countersinking of the BMR driver... superb! I know that had to have been a tough job to do, but it looks like you overcame the difficulty with flying colors. I wonder if you could elaborate on just how you accomplished that, i.e., what template kit you used and anything that can help a guy like me do the same thing? I tried to private message you, but I don't know how to do that, or that you can even do it any longer. Nevertheless, I wanted to send you praise for the fabulous job you did. Nice stereo system, too! Thanks in advance for anything you care to share.

William
 
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