New Towers-BMR Philharmonic, Revel F208, or other?

[fineMen]

... very similar with very few exceptions...

He is an individual with his own taste and preferences. As an artist in the field his works don't depend on the wider public's sympathy. The art given from specialst to the specialist who really appreciates the usage of e/g a 'true ribbon' tweeter. Different with e/g Revel, Harman. They want a product that meets wide spread demands, not to 100%++ but to 95% mostly, maybe.

If it is a gamble, as it now seems to be, I would suggest to go for the more safe option with the widest approval from the regular Joe.

Anyway, the bass again. 25Hz@-3dB. If it is true it is too much boom in-room! Not needed to begin with, as nearly all records have simply nothing below 30Hz. And 30HZ produced really clean, I cannot really hear, really!

If I were to pay that much for a simple (effectively low tech) speaker-set I would for sure, due to all responsible recommendations I find in the internet, positively add an equalizer at least for the bass. In short: no true hifi without an equalizer, spinorama back and forth.

 

[tw 2022]

He is an individual with his own taste and preferences.

they measure very well .. at least in terms of freq response ...

 

[Speaker_tweaker]

Someone did, the aforementioned Audioholics:

This is the BMR Tower’s ground plane measurement on Audioholics review

https://www.audioholics.com/tower-speaker-reviews/philharmonic-bmr/conclusion/BMRTowerlowfrequencyresponse.jpg/image

Edit: @mj30250 beat me to it

OK, so that's a better measurement. The other issue is where is 0dB? Because there's a 5dB tilt from 40Hz to 250Hz, it's hard to guess. The -10dB point is normally in context of the broadband sensitivity, which we don't have. We could assume it's 97dB or so, in which case the -10dB point is ~22Hz, which is similar to the Revel. We could also assume it's lower, like 94dB, but then the speaker is likely going to have some upper bass coloration.

 

[Speaker_tweaker]

I overlaid the bass from Amir's V2 measurement of the F208 onto the BMR ground plane measurement. Yes, the BMR looks to have a bit more extension, but the Revel has a bit more boom. As a guess - and it's just a guess - I would say the bass of the Revel looks better overall.



Attach files

 

[tw 2022]

I overlaid the bass from Amir's V2 measurement of the F208 onto the BMR ground plane measurement. Yes, the BMR looks to have a bit more extension, but the Revel has a bit more boom. As a guess - and it's just a guess - I would say the bass of the Revel looks better overall.



Attach filesView attachment 242039

Yeah if you like midbass ...if you want level extension, not so much...

 

[Speaker_tweaker]

Yeah if you like midbass ...if you want level extension, not so much...

How is that? F208 is flat, while the BMR is sagging. I suspect the box volume on the BMR is too large and that is why it looks like that. Having too large a box can also mean poor power handling.

 

[tw 2022]

How is that? F208 is flat, while the BMR is sagging. I suspect the box volume on the BMR is too large and that is why it looks like that. Having too large a box can also mean poor power handling.

That's a small mid bass bump vs a slight roll off , that is if you believe both measurements to be accurate...it's also dependent on the mid and treble response which is covered in pir...it's a partial graph...let's not pretend this says much....

 

[Speaker_tweaker]

.let's not pretend this says much....

Correct.

 

[phoenixdogfan]

For $4k, you should also consider the March Audio Sointuva. Probably as good if not a better bass performer than the Sierra LX with narrower directivity and more artisan cabinetry. I know it got a going over in one of the threads, but there was nothing found that was not correctable with better QC on the part of the owner. If you should decide to buy from him, have a heart to heart and set out your expectations. If he is agreeable, I would see no reason to demur just because someone found one bad sample his production. It seems like it would do just about everything a floor stander would do, in a much more compact package--much like the Kef Reference 1 Meta.

 

[Head_Unit]

F208 is flat, while the BMR is sagging. I suspect the box volume on the BMR is too large and that is why it looks like that. Having too large a box can also mean poor power handling.

I've long felt that "drooping" response speakers "undertuned" can better match room gain. Obviously that's a wildly vague and broad statement...but still. Flat in a quasi-anechoic chamber is meaningless versus actual rooms. Heck once when I met Richard Small he agreed the -6 or even -10 dB point was more significant than the -3 dB point used originally as a mathematical convenience carried over from electrical filter theory. In vented boxes maybe a more key point is the tuning frequency, since below that output becomes quickly useless.

As for the power handling, yes but no. A big low tuned box may bottom out more easily, but that's if it is putting out more low bass SPL. A more compact sealed box for same woofer would "handle" more power but by choking off the low bass.

My nomination at vaguely this price https://www.stereophile.com/content/monitor-audio-silver-500-7g-loudspeaker
I loved the Silver 300 when I spent some hours with them at Upscale Audio, astounded that not only did they sound great with everything like the usual jazz and classical, they could really crank out the heavy metal, even Motorhead live (!!). I want to hear these Silver 500 sometime.

 

[Dennis Murphy]

He is an individual with his own taste and preferences.

Well, I have a taste for science and accurate sound reproduction A good bit of work went into the tower's box tuning. I always call on Paul Kittinger to do this part of the design work. He uses extremely sophisticated transmission line design software that optimizes the location of the drivers and terminus, as well as the usual cabinet and port or terminus dimensions. Using the measurement tools available to me, the tower's actual performance matched his modeling almost exactly. For the record, here are the simulation results:
System bass response (red line):

F3 is 24-25 Hz, f6 is 21-22 Hz and f10 is just below 20 Hz. The SPL is 103 dB before BSC effects.


Woofer (red line) and port (blue line) responses:

Woofer excursion (red line):

Port air velocity:

The peak velocity is 4.5% of the speed of sound, or 15.5 m/s.


Impedance characteristic (red line):

 

[fineMen]

Well, I have a taste for science and accurate sound reproduction A good bit of work went into the tower's ...

I never doubted that. to the contrary. I'm in the camp of better having a slightly tilted bass response, especially when it goes as deep as here. Anecdotally I'm working on a very small speaker now (just 9liters) and with that I have to deal with bass extension versus available SPL versus excursion versus port noise (chuffing). From my measurements I would tend to say, that the room gain @40Hz or so can be as high as 6dB, the ubiquitous peaks 'n dips added onto that of course. Tested in my kondo 6m high, 10m long, 4m wide plus wintergarden (same size again) occasionally, and within some other locations likewise.

That's kind of affirmed by the Revel's shallow frequency response in the deep bass with their cost-no-object types. These would give, +room gain, effectively a slight hump towards the lowest register, as regular Mary and Joe like it the most.

From my perspective of a practical man, I won't argue with another dB here or there in the bass alignment. It is not the frequency response in particular, but that criteria mentioned above. A multi-faceted problem with so many unknowns. E/g where to seat the listener, actually?

Anyway, I would strongly suggest using an equalizer once the demand for quality reaches a level where 4k$ of an expense for speakers is justified. The e/q is a must. I dare to say, that the layman shall assure, that an expert would come in and adjust it as a service contained in the delivery fee. Or, yes, do the DIY. But in that case the DIYer better knows how to measure the actual performance for quality control and not the least e/q-ing the bass ... easy-pleasy. What do You think about it?

 

[Spkrdctr]

Well, I have a taste for science and accurate sound reproduction A good bit of work went into the tower's box tuning. I always call on Paul Kittinger to do this part of the design work. He uses extremely sophisticated transmission line design software that optimizes the location of the drivers and terminus, as well as the usual cabinet and port or terminus dimensions. Using the measurement tools available to me, the tower's actual performance matched his modeling almost exactly. For the record, here are the simulation results:
System bass response (red line):


View attachment 242140


F3 is 24-25 Hz, f6 is 21-22 Hz and f10 is just below 20 Hz. The SPL is 103 dB before BSC effects.


Woofer (red line) and port (blue line) responses:


View attachment 242141


Woofer excursion (red line):


View attachment 242142


Port air velocity:


View attachment 242144


The peak velocity is 4.5% of the speed of sound, or 15.5 m/s.


Impedance characteristic (red line):


View attachment 242143

Dennis, thanks for the data. I did not have that and was just passing on the good comments I have heard about the BMRs. Nice to see the data looks great! Keep me in mind when you have that 75% off April 1st sale!

 

[tw 2022]

Keep me in mind when you have that 75% off April 1st sale!

lol..best keep an eye on estate sales with clueless relatives

 

[Speaker_tweaker]

Well, I have a taste for science and accurate sound reproduction A good bit of work went into the tower's box tuning. I always call on Paul Kittinger to do this part of the design work. He uses extremely sophisticated transmission line design software that optimizes the location of the drivers and terminus, as well as the usual cabinet and port or terminus dimensions. Using the measurement tools available to me, the tower's actual performance matched his modeling almost exactly.

Thanks Dennis. Your presence is making me feel bad for dragging your speaker through the mud a bit!

I assume when you say "Using the measurement tools available to me" you mean nearfield bass measurement? Perhaps the port is close enough to the woofer to create enough crosstalk to account for some of the discrepancy between your measurement and the audioholic measurement? My understanding is you need several drive unit diameters between the port and the driver to reasonably minimize crosstalk. Overestimating the effective radiating area of your tapered port would also tilt the bass up in the measurement.

Regarding the simulation, I'm surprised Kittenger was able to get that bass profile out of that woofer in his mathcad simulation. I would expect results more in line with what Audioholic actually measured.

Regarding the F208, you might be interested to know they use what appears to be an off-the-shelf SB acoustics woofer, possibly the SB23NBACS45-4. When I'm selecting a woofer I calculate the reference efficiency (η0), the acoustic power, and the swept volume. This allows me to compare some of the gross performance aspects of two drive units. I was going to make a comparison of the two SB woofers used in the F208 to the single scanspeak driver used in the BMR tower using those three parameters, but since you're here I will refrain from doing so.

 

[Everett T]

How is that? F208 is flat, while the BMR is sagging. I suspect the box volume on the BMR is too large and that is why it looks like that. Having too large a box can also mean poor power handling.

It's a TL loading and designed to accommodate room gain. It's not a typical ported rolloff till below box tunning. You're trying hard to find fault where there isn't a whole lot. Maybe do some research before trying to tear the speaker apart. FFS

 

[Dennis Murphy]

Thanks Dennis. Your presence is making me feel bad for dragging your speaker through the mud a bit!

I assume when you say "Using the measurement tools available to me" you mean nearfield bass measurement? Perhaps the port is close enough to the woofer to create enough crosstalk to account for some of the discrepancy between your measurement and the audioholic measurement? My understanding is you need several drive unit diameters between the port and the driver to reasonably minimize crosstalk. Overestimating the effective radiating area of your tapered port would also tilt the bass up in the measurement.

Regarding the simulation, I'm surprised Kittenger was able to get that bass profile out of that woofer in his mathcad simulation. I would expect results more in line with what Audioholic actually measured.

Regarding the F208, you might be interested to know they use what appears to be an off-the-shelf SB acoustics woofer, possibly the SB23NBACS45-4. When I'm selecting a woofer I calculate the reference efficiency (η0), the acoustic power, and the swept volume. This allows me to compare some of the gross performance aspects of two drive units. I was going to make a comparison of the two SB woofers used in the F208 to the single scanspeak driver used in the BMR tower using those three parameters, but since you're here I will refrain from doing so.

The mic was at most 1/4" from the woofer dust cap when I did the nearfield measurement. I really doubt there was any bleed-through from the port, or vice versa.

 

[Speaker_tweaker]

The mic was at most 1/4" from the woofer dust cap when I did the nearfield measurement. I really doubt there was any bleed-through from the port, or vice versa.

Here's a quote from Jack Hidley, former director of engineering at NHT:

"An example of this is measuring a 10" woofer and a 3" port. When you measure either the port or the woofer, there is far too much crosstalk in the measurement from the other radiator. To minimize the crosstalk to a low enough level to get acceptable results, you need to have several radiator diameters between them. When you have the port and woofer nearly touching each other, and then splice these measurements together, the results are very, very inaccurate. I consider them worthless.

To determine how bad they are, build a subwoofer with two ports. One in front and the other in back. Plug one port while measuring the other port and the woofer. Do this twice, once for the front port and another time for the rear port. Compare the results."

 

[Lsc]

I don’t have any experience with BMR but it seems like a well designed speaker. I do have experience with Revel having owned or currently own the F12, F208, F228Be and Salon2 (along with M12, S12, C12, C208 and Voice2).

The F208 is a very good speaker and I would recommend them to anyone. And if you want a great HT/2 channel combo, the C208 is an amazing center channel as well.

The biggest thing with Revels and it applies to all the speakers I owned but especially the F228Be and Salons is their ability to play incredibly loud with perfect clarity and accuracy.

Good luck with your selection. If you buy the Revels from Crutchfield, you can return them.

 

[Dennis Murphy]

Here's a quote from Jack Hidley, former director of engineering at NHT:

"An example of this is measuring a 10" woofer and a 3" port. When you measure either the port or the woofer, there is far too much crosstalk in the measurement from the other radiator. To minimize the crosstalk to a low enough level to get acceptable results, you need to have several radiator diameters between them. When you have the port and woofer nearly touching each other, and then splice these measurements together, the results are very, very inaccurate. I consider them worthless.

To determine how bad they are, build a subwoofer with two ports. One in front and the other in back. Plug one port while measuring the other port and the woofer. Do this twice, once for the front port and another time for the rear port. Compare the results."

I've never done his experiment, but I'm very skeptical. My nearfield measurement matched the simulation exactly.