Philharmonic BMR Speaker Review

[Colonel7]

Ja, these infamous details. I don't ignore them. I only do not want to discuss the whole design in total. There is a gross problem with the ribbon. Reiterated, I only feel that a lot of the talk regarding something special is an aftermath to a choice that was originally due to some other criteria.

If You and others don't see how and by far it gets a bit off at around 3-4kHz (actually and really the most sensitive frequencies for the human hearing, by the way), and so under different aspects, I couldn't tell either. So, I won't tell ;-)

@Dennis, I liked it more with straight sidewalls

I'd hardly call it gross. All designs and implementations have tradeoffs and this is a really interesting and well performing option for an 8-12 ft listening distance like in a larger family or entertaining room if floorstanders are not desired.

 

[ctrl]

If You and others don't see how and by far it gets a bit off at around 3-4kHz (actually and really the most sensitive frequencies for the human hearing, by the way), and so under different aspects, I couldn't tell either. So, I won't tell ;-)

My translation program could not translate this sentence meaningfully, but if the wide radiation in the range 3-4kHz is meant, even the use of a 0.75'' tweeter would not cause a significant change, because the baffle is responsible for this - unless the tweeter sits in a large waveguide.

As shown in the simulation in Post#92, the problem can be almost completely avoided by changing the baffle.

 

[GelbeMusik]

My translation program could not translate this sentence meaningfully, but if the wide radiation in the range 3-4kHz is meant, even the use of a 0.75'' tweeter would not cause a significant change, because the baffle is responsible for this - unless the tweeter sits in a large waveguide.

As shown in the simulation in Post#92, the problem can be almost completely avoided by changing the baffle.

Some design decisions are surely based on subjective preferences, which cannot be discussed. They have been mentioned already. If You tempt to change the baffle, it is up to You. But that's not the speaker which is tested here. I did literally dozens of speakers already. If You don't trust my contributions, a self-examination might be in order:

https://www.audiosciencereview.com/...-xt-6-speaker-review.14662/page-7#post-455717

Since nobody followed my recommendation yet, what is the talking all about?

Of course it is utterly o/k to build the BMR if one likes the sound signature!

 

[Selah Audio]

I've tried the 70-10 in a number of configurations, including my Philharmonic 3 crossed well above the factory's suggested point, and distortion has always exceeded 1.5% at 90 dB, one meter. And that's based on of tests on dozens of production speakers. So I find your measurements very surprising. Perhaps you're using steeper slopes than the suggested 4th order acoustic?

I would have to go back and look but probably 4th order acoustic. It's probably more related to the crossover point being higher which may help the 64-10 as well.

 

[Dennis Murphy]

Sorry, I wasn't paying attention. But it makes very little difference in the simulation.


This should not eliminate the main problem in the horizontal radiation, because the front baffle would have to be modified.

A rounded baffle placed close to the tweeter and midrange and the woofer in B&W style would optimize radiation. Then the horizontal radiation would be....

View attachment 74283

Simulation with [email protected] horizontal normalised deg0-90
View attachment 74284
Due to the "virtually" narrower baffle, the edge diffraction shifts to higher frequencies and due to the lateral rounding the effect is less dramatic and more even (around 5kHz).

The less advantageous vertical dispersion remains unchanged - vertically wide radiating midrange driver with narrow radiating tweeter leads to a " step change " in the vertical dispersion.
Simulation with [email protected] vertical normalised deg0-90 (negative angles show the radiation upwards)
View attachment 74296

Well, we'll have to see how much difference the new cabinet makes. I'll make a stab at that later today. In any event, the narrow flat front baffle you show wouldn't be practical with the woofer in place. It either wouldn't fit, or you would have to increase the overall cabinet width by some gargantuan amount.

 

[Dennis Murphy]

I would have to go back and look but probably 4th order acoustic. It's probably more related to the crossover point being higher which may help the 64-10 as well.

How high did you cross?

 

[Dennis Murphy]

I guess there has to be some compromise made if their is an insistence not to use a waveguide.

There would need to be some compromise with or without a wave guide.

 

[Dennis Murphy]

Ja, these infamous details. I don't ignore them. I only do not want to discuss the whole design in total. There is a gross problem with the ribbon. Reiterated, I only feel that a lot of the talk regarding something special is an aftermath to a choice that was originally due to some other criteria.

If You and others don't see how and by far it gets a bit off at around 3-4kHz (actually and really the most sensitive frequencies for the human hearing, by the way), and so under different aspects, I couldn't tell either. So, I won't tell ;-)

@Dennis, I liked it more with straight sidewalls

Well, I would be happy to sell you either version.

 

[Ericglo]

Some design decisions are surely based on subjective preferences, which cannot be discussed. They have been mentioned already. If You tempt to change the baffle, it is up to You. But that's not the speaker which is tested here. I did literally dozens of speakers already. If You don't trust my contributions, a self-examination might be in order:

https://www.audiosciencereview.com/...-xt-6-speaker-review.14662/page-7#post-455717

Since nobody followed my recommendation yet, what is the talking all about?

Of course it is utterly o/k to build the BMR if one likes the sound signature!

I guess I am confused why you seem to be belaboring this ribbon vs dome discussion.

 

[ribosradagast]

Well, we'll have to see how much difference the new cabinet makes. I'll make a stab at that later today. In any event, the narrow flat front baffle you show wouldn't be practical with the woofer in place. It either wouldn't fit, or you would have to increase the overall cabinet width by some gargantuan amount.

Guys I ran all the simulations and came up with the ideal cabinet for the bmr, let me know what you think

I present the "bmr gourd"

 

[Dennis Murphy]

Guys I ran all the simulations and came up with the ideal cabinet for the bmr, let me know what you thinkView attachment 74341
I present the "bmr gourd"

My place in audio history is secure. Could you please whip me up one test cabinet? Thank you.

 

[Colonel7]

Guys I ran all the simulations and came up with the ideal cabinet for the bmr, let me know what you thinkView attachment 74341
I present the "bmr gourd"

You forget the acutely angled gourd chamfers because you gotta get the plain box sound too!

 

[ctrl]

In any event, the narrow flat front baffle you show wouldn't be practical with the woofer in place. It either wouldn't fit, or you would have to increase the overall cabinet width by some gargantuan amount.

One could let the rounding of the baffle run out towards the woofer or, as already mentioned, place the woofer in B&W style.
It is of course another question whether potential customers still like such a baffle or whether they turn away in disgust

 

[q3cpma]

I gave a valid (!) method for DIY'ing that sought after investigation. It is added to the TANNOY thread. No response so far. Seems to be an US American thing to just ignore. I was told so, sorry.

( => https://www.audiosciencereview.com/...-xt-6-speaker-review.14662/page-7#post-455717 )

But does it make sense waving with AES "papers", maybe 60y old, showing only some graphs, and then calculating numbers to a fraction of a percent for a miss or hit verdict? Please do that self-evaluation I recommended, it is easy. I developed the method during a short lunch break. It shouldn't need more than 10 minutes to get some motivating results.

Well, it may be that describing such an experience using text only can be a bit messy, some image and good english would help. Anyway, I find it better to aim for low distorsion all the time, makes such questions superflous.

 

[hardisj]

Question for you guys:
I try to do video reviews of speakers I test. I'm pretty bogged down right now with speakers I need to review. Do you guys see a need for this one to be rolled up in to a video? I'm erring on punting and moving on to other tests.

Here's a link to my YT channel to get an idea of the reviews I do:
https://www.youtube.com/channel/UCW_IqM21u0J-zsKtCq4Gj2w

 

[ribosradagast]

Question for you guys:
I try to do video reviews of speakers I test. I'm pretty bogged down right now with speakers I need to review. Do you guys see a need for this one to be rolled up in to a video? I'm erring on punting and moving on to other tests.

Here's a link to my YT channel to get an idea of the reviews I do:
https://www.youtube.com/channel/UCW_IqM21u0J-zsKtCq4Gj2w

A youtube search for "philharmonic bmr review" yields almost nothing of relevence. Seems like you'd have the market cornered~

 

[q3cpma]

Question for you guys:
I try to do video reviews of speakers I test. I'm pretty bogged down right now with speakers I need to review. Do you guys see a need for this one to be rolled up in to a video? I'm erring on punting and moving on to other tests.

Here's a link to my YT channel to get an idea of the reviews I do:
https://www.youtube.com/channel/UCW_IqM21u0J-zsKtCq4Gj2w

I'd rather see more comments about the measurements than time wasting (for everyone) videos, personally. Technical matters aren't fit for videos, anyway.

 

[Icboschert]

Agreed with the previous posts. You'd have much more exposure on YT if you posted it, however there is redundancy for you since it is covering all of the material you've already written for the most part.

 

[617]

I guess I am confused why you seem to be belaboring this ribbon vs dome discussion.

He's trying to get Dennis to send him a free pair

 

[hardisj]

I'd rather see more comments about the measurements than time wasting (for everyone) videos, personally. Technical matters aren't fit for videos, anyway.

YT is a very, very popular format for reviews. And with all the YT reviewers these days, I thought I could do something different with my channel by offering objective data, *actually be critical of crappy stuff* and teach what the data means and why it is important. Without that, I feel the divide will continue with the subjective vs objective crowds. Relatively speaking, few people will come to this site to view the data; they want to watch a video of someone talking about how it sounds. If I can use that as my “bait” to get them to also learn about measurements then it’s more useful than just hoping they’ll want to come to a data-oriented site and then take the time to research, and learn what it means. So, I absolutely will create YT videos for reviews. Just not all of them.

It’s just that this is a DIY design that probably won’t be looked for on YT because people who are building/buying this probably know already the importance of measurements and have (or will have) seen the data. Thus, my reasons for moving on to the next review.