Philharmonic Audio BMR Speaker Discussion

[bogart]

All the talk on the Affordable Accuracy Monitor thread about the BMR piqued my curiosity and got me reading about this very interesting speaker. It seems to have a really excellent reputation and measures very well. This has also been my introduction to @Dennis Murphy - I'm so grateful for folks like you engaging so generously with folks interested to learn more about your work and enjoy it. Thank you, sir!

I'd like to start a discussion of this speaker - inviting folks who have one / heard them / etc. to share their thoughts and impressions.

As I've read more, I'm wondering whether I might really enjoy these!

From what I read, it looks like the two options for acquiring new BMR's today are:
1. Complete(-ly gorgeous) build by Salk
2. Flatpack cabinet from Speaker Hardware + Kit from Meniscus Audio to construct your own

Question 1: Go active?
I've had a persistent interest in building a kit speaker for some time now, and wonder whether this is the one (I keep side-eyeing the LXMini too - I see you over there!). I completely grant that this may be a ridiculous question given Dennis' excellent crossover design reputation, but I wonder whether these are a good candidate for fully active speakers using Hypex DSP amps (such as this 3-way option). As their current incarnation seems to have reasonable demands on the amp and great performance, is there anything to be gained from this approach?

Question 2: L-C(?)-R
Does anyone have experience using these three-across as a front stage? Based on its dispersion, would it lend itself to angled-up horizontal mounting below a screen as a center channel?

 

[dwkdnvr]

My personal thought is that the extra $$$ for going active with the BMR doesn't make any sense. The measurements speak for themselves here - you aren't going to make it any better. (particularly since you need to buy the kit to get the tweeter, and that already includes the passive components) Instead, spend the $$$ you would have spent on the Hypex amps and put it towards a couple subs and appropriate DSP integration.

 

[bogart]

That's my intuition too, @dwkdnvr.

Playing Devil's advocate: Meniscus does say they can customize kits, so perhaps one could delete the passive components and save a portion of the costs. If one didn't have amplification already, these are very affordable routes to Hypex amps, and you save the labor of building crossovers (or the upcharge of $125 to buy them). You also gain the ability to do room correction 'in-speaker' (I think?), and potentially eliminate some rack components too. That'd all be down to personal preference though, and not really after the usual active vs. passive benefits since this one is so well designed.

 

[napilopez]

I don't have much to contribute as I've never heard them, but the BMRs are probably the speaker I'd built if I were looking to go the DIY kit route. Bass extension, super wide directivity, standmount. My kind of speaker.

Anyway, here's something you might not have seen before: Someone built a pair of BMRs out of Corian a few months back. The Salk finished are gorgeous too, but these are quite a striking modern finish:

 

[Martin]

I would love to hear a pair. (and his Philharmonica 3, too)

Martin

 

[bogart]

I don't have much to contribute as I've never heard them, but the BMRs are probably the speaker I'd built if I were looking to go the DIY kit route. Bass extension, wide directivity, standpoint. My kind of speaker.

Anyway, here's something you might not have seen before: Someone built a pair of BMRs out of Corian a few months back. The Salk finished are gorgeous too, but these are quite a striking modern finish:

Well now you’ve blown my mind! Those are their own kind of style but I do love it. I can imagine they weigh every bit of the 43 lbs. they quote them as! I’ve never heard of Corian in this application... I have even less tooling to work with that than wood!

 

[HooStat]

I am also wondering if we need the port. Especially since I would be using them with subs. I asked about this in another thread but didn't get an answer. My guess is that deleting the port is not a problem at all - it is kind of like stuffing the port.

If I build these, I would ditch the cross-over and do it all via DSP. Not for any reason except that it would be more interesting. I think the world is going this direction and it is easier to experiment and learn (and probably easier to destroy the speakers).

 

[ribosradagast]

Dang you beat me to it! I am also having a hankering for some DIY action with these.

I tallied up the total cost earlier today with shipping to Maryland and it comes to $1419, plus some for stain and dampening material. That's a lot of DIY money... Also note that both Meniscus and Speaker Hardware are reporting supply chain issues right now.

 

[bogart]

It is even more to Canada! In my case, the supply chain issues just give me an excuse to ruminate on the idea longer.

I think the thing that gets me about these is that they’re not just good with a good reputation, they’re also interesting! Based on the speakers I’ve never gotten rid of, I don’t have to worry about the resale penalty on DIY. So, even though they’re at the higher end of fun project budgets, they’re likely going to be more fun than buying alternatives at the same price — more interesting design, certainly.

 

[Sancus]

Every time I look at these I really wish the woofer didn't look like that, lol. It's almost made worse by how perfect those Corian cabinets look.

 

[617]

Active speakers are 'technically' always better, but the added cost and complexity only makes sense (at present) with certain speakers. Linkwitz's designs require crazy filters which would be costly or impossible to implement passively, burning tons of amplifier power in the process. The same is true of bigger box speakers - it makes sense to use a separate amp for the bass driver if it is a big beast of a thing, requiring big inductors for the low pass filter (and on the midrange, huge capacitance values.) But for a speaker like the BMR, with a modest woofer and a tiny midrange, the gains in an active implementation are quite low. Given Dennis' Murphy's experience with passive networks I would highly recommend sticking to the verified design.

If you convert a speaker to active configuration, you are designing a new speaker. You would need to measure it and test it. Yes, testing an active filter is easy, but it's a new design. Simply knowing the crossover points and slopes is not remotely enough information to accomplish this task.

 

[ribosradagast]

Every time I look at these I really wish the woofer didn't look like that, lol. It's almost made worse by how perfect those Corian cabinets look.

Yeah the thing is a bit butt-ugly with the exposed drivers and the tall and skinny cabinet.

I was considering shoving some magnets in the case and then popping on a simple grille to cover it up.

 

[bogart]

Every time I look at these I really wish the woofer didn't look like that, lol. It's almost made worse by how perfect those Corian cabinets look.

It's a pretty aggressive contrast, isn't it?

Active speakers are 'technically' always better, but the added cost and complexity only makes sense (at present) with certain speakers. Linkwitz's designs require crazy filters which would be costly or impossible to implement passively, burning tons of amplifier power in the process. The same is true of bigger box speakers - it makes sense to use a separate amp for the bass driver if it is a big beast of a thing, requiring big inductors for the low pass filter (and on the midrange, huge capacitance values.) But for a speaker like the BMR, with a modest woofer and a tiny midrange, the gains in an active implementation are quite low. Given Dennis' Murphy's experience with passive networks I would highly recommend sticking to the verified design.

If you convert a speaker to active configuration, you are designing a new speaker. You would need to measure it and test it. Yes, testing an active filter is easy, but it's a new design. Simply knowing the crossover points and slopes is not remotely enough information to accomplish this task.

Thanks for the extra detail - this really helps me understand the interaction of the crossover 'penalty' with the design itself. Even as a relatively technical person, I've struggled to integrate my understanding of the various tradeoffs as well as you state them here. Super helpful explanation!

So, I'm definitely convinced by the "stay passive" voices in the room - you make a clean and compelling case.

 

[617]

Yeah the thing is a bit butt-ugly with the exposed drivers and the tall and skinny cabinet.

I was considering shoving some magnets in the case and then popping on a simple grille to cover it up.

Those Scanspeak carbon pulp drivers were the best in the world when they first came out, I think they're quite nice looking. Beauty is subjective I suppose.

 

[617]

It's a pretty aggressive contrast, isn't it?


Thanks for the extra detail - this really helps me understand the interaction of the crossover 'penalty' with the design itself. Even as a relatively technical person, I've struggled to integrate my understanding of the various tradeoffs as well as you state them here. Super helpful explanation!

So, I'm definitely convinced by the "stay passive" voices in the room - you make a clean and compelling case.

If it was a worse speaker I might suggest you go for it and learn something on the way, but Dennis Murphy is a passive crossover artist, and I don't say that ironically. There are designers whose passive networks display real talent and he's one of them. Jeff Bagby, RIP was another.

 

[ribosradagast]

Those Scanspeak carbon pulp drivers were the best in the world when they first came out, I think they're quite nice looking. Beauty is subjective I suppose.

Yeah I'm sure it'll grow on me as well, especially if I built it with my own two hands!

We also have kids running around 100% of the time and something about seeing drivers out in the open just makes them go crazy and start poking haha

 

[Ericglo]

As was mentioned, the measurements from Audioholics look so good that attempting active might not improve on the design.

If one wanted to try active, then maybe swap out the woofers for something else. I prefer tower speakers, so I would try a dual woofer system with the BMR and tweeter.

There is also a robust thread over on AVS discussing the BMRs and Dennis's speakers.

 

[muad]

Every time I look at these I really wish the woofer didn't look like that, lol. It's almost made worse by how perfect those Corian cabinets look.

I had the BMR at one point, the driver does look better in person

 

[Webninja]

At one point I was waffling between BMR and the Philharmonic 3s (big regret on not pulling the trigger). I had a few emails with Dennis, and we didn’t finalize anything, but I believe it was possible to have the BMR as a tower.

That’s what I would like to build, BMR Tower, and I realize that might alter the bass as there would be more volume. I wonder if I can do sealed plus tower form.

 

[q3cpma]

Active speakers are 'technically' always better, but the added cost and complexity only makes sense (at present) with certain speakers. Linkwitz's designs require crazy filters which would be costly or impossible to implement passively, burning tons of amplifier power in the process. The same is true of bigger box speakers - it makes sense to use a separate amp for the bass driver if it is a big beast of a thing, requiring big inductors for the low pass filter (and on the midrange, huge capacitance values.) But for a speaker like the BMR, with a modest woofer and a tiny midrange, the gains in an active implementation are quite low. Given Dennis' Murphy's experience with passive networks I would highly recommend sticking to the verified design.

If you convert a speaker to active configuration, you are designing a new speaker. You would need to measure it and test it. Yes, testing an active filter is easy, but it's a new design. Simply knowing the crossover points and slopes is not remotely enough information to accomplish this task.

This, I wouldn' try my hand at DIY active crossover design, especially for more than 2 ways. This is sad, though, designers could design a good DSP crossover and give it in the pack, for adventurers.