Can we discuss the BMR Tower?

[ctrl]

James' ground plane measurements almost always show a declining response setting in relatively early.

If he doesn't do anything wrong with the measurements (which is difficult), then the speakers are just tuned accordingly.

Which I think is quite plausible, since every manufacturer is currently trying to achieve the highest possible sensitivity, which is inevitably at the expense of low-frequency capability.

Compare these with the results for the giant Perlisten S7t tower (shown below). The factory spec for the speaker is a -10 dB point of 22 Hz.

We can go through the competitor's case and proceed identically.
As you correctly quote, the manufacturer indicates an f10 of 22 Hz. James' measurements shows an f10 of about 27Hz.

That's a pretty good match, isn't it? I don't expect manufacturers to be completely honest, but it should still be within the realm of possibility.
Which is just about the case here.

But with almost an octave difference (as in the PBT measurements, f3 25Hz versus f3 53Hz), one should examine the difference in the free-field measurements carefully.

With room gain, the BMR tower is flat to 25 Hz, with useful output at 20 - 22 Hz.

The "standard", if nothing else is stated, is that the specified f3 refers to a free-field measurement.
Your specification even explicitly states "25 Hz - 20kHz (+ 1.5 / - 3db) Anechoic".

According to James' measurements, however, it should say "(+1.5/-6dB)" or "50 Hz - 20kHz (+ 1.5 / - 3db) Anechoic", which is a world of difference in the low bass range, where you have to fight for every Hz.

 

[abdo123]

Which I think is quite plausible, since every manufacturer is currently trying to achieve the highest possible sensitivity, which is inevitably at the expense of low-frequency capability.

Wait What? it's very difficult currently to find a Hi-Fi speaker with a sensitivity higher than [email protected]. This comment is quite controversial.

In my opinion the current trend is to reduce sensitivity in exchange for frequency response smoothness.

 

[ctrl]

Wait What? it's very difficult currently to find a Hi-Fi speaker with a sensitivity higher than [email protected]. This comment is quite controversial.

In my opinion the current trend is to reduce sensitivity in exchange for frequency response smoothness.

That's how far apart subjective impressions can be, which makes it all the more important that the objectively measurable data is correct

 

[tktran303]

The "standard", if nothing else is stated, is that the specified f3 refers to a free-field measurement.

There is no "standard".

This is the Revel F328Be, a top speaker from their stable. It's about US$8,000 for a single speaker.

Dennis’ speaker is less than $4,000 a pair.
So you could buy FOUR of Dennis’ speaker for a single single F328Be.

Any I digress. Revel is a company owned by Harman owned by Samsung. So as an audio company the access to more R&D than just about anyone, except Apple IMHO.

Here is the manufacturer's spec:

F328Be | 3-Way Triple 8" Floorstanding Loudspeaker

The Revel F328Be is the flagship floorstanding loudspeaker from our award-winning PerformaBe series. The F328Be includes a 1-inch (25mm) beryllium tweeter driven by massive 85mm dual ceramic magnets. The powerful all-new tweeter and 6th-generation ceramic-coated, cast-aluminum Acoustic Lens...

www.revelspeakers.com

Low frequency extension: 24Hz (-10dB); 26Hz (-6dB); 35Hz (-3dB)

Here is armirm's measurements taken with a Klippel NFS measurements:

Revel F328Be Speaker Review

This is a review and detailed measurements of the Revel F328Be floor standing speaker. I purchased a single unit through our company (Madrona) with kind discount from Harman Sales (I asked for a review sample from the PR group but was told "don't call us, we will call you."). The retail cost...

www.audiosciencereview.com

I've inserted the F3/6/10, compared to the red arrow line as the reference sensitivity.

To be clear, for those readers who are not loudspeaker designers, the NFS measurement is not wrong. And that quoted specification is not wrong. And no one is trying to mislead anyone.

It’s just different ways of representing data.

 

[ctrl]

There is no "standard".

This is precisely why the word "standard" is in quotation marks.
But it is common practice in all forums and hi-fi circles that if no further details are given, that one assumes free-field conditions for the measurements and specifications derived from them - especially after CTA-2034-A becomes more and more established.

This is the Revel F328Be, the current top of the line speaker from Revel staple. It's about US$8,000 for a single speaker. You could buy TWO pairs of Dennis' speaker for the price of a SINGLE F328Be.

Sorry, I didn't know there is a direct correlation between speaker price and correctness of manufacturer specification

Price is not a factor in the issue.
It's about reliable and comparable manufacturer specifications or at least a note that helps with the classification - like Klipsch, for example, who at least include "in a typical room" or something similar in their fantasized sensitivity specifications.

I've inserted the F3/6/10, compared to the red arrow line as the reference sensitivity.

In your example you should use the measurement of the loudspeaker that is considered correct and not the one with errors.

About the incorrectness of the data specified by the manufacturer or problems with the measurement, makes up a large part in both threads about the F328Be speaker.

It is usually not easy to determine the average sound pressure level. Therefore, if the data is available, I would recommend using the average SPL from Pierre's website for the Revel F328Be (average of the frequency response from 300-10000Hz) or @MZKM (average of the frequency response from 300-3000Hz) .


Accordingly, the measurement shows the following f10/f6/f3 with 28/45/63 Hz.

This is still a way from the specified sound pressure levels

Low frequency extension: 24Hz (-10dB); 26Hz (-6dB); 35Hz (-3dB)

Revel is rightly criticized for it.

To be clear, for those readers who are not loudspeaker designers, the NFS measurement is not wrong. And that quoted specification is not wrong. And no one is trying to mislead anyone.

It’s just different ways of representing data.

I would not be so uncritical about that. Legally, I agree with you completely; no one has acted unlawfully.

However, there are "unwritten laws" that many people adhere to, such as diagrams with 50dB scaling, indication of smoothing, frequency response measurements under free field conditions,...

Otherwise, you mislead consumers who cannot spend months reading up on the subject.

Or the next thing you know, you'll have a small bookshelf speaker with 90dB sensitivity and an f3 of 30Hz. The manufacturer could argue "Our research has shown that our speakers are usually placed in the corner of the room, so we raise the frequency response in the low frequency range by 18dB".

 

[tktran303]

This is precisely why the word "standard" is in quotation marks.
But it is common practice in all forums and hi-fi circles that if no further details are given, that one assumes free-field conditions for the measurements and specifications derived from them - especially after CTA-2034-A becomes more and more established.



Sorry, I didn't know there is a direct correlation between speaker price and correctness of manufacturer specification

Price is not a factor in the issue.
It's about reliable and comparable manufacturer specifications or at least a note that helps with the classification - like Klipsch, for example, who at least include "in a typical room" or something similar in their fantasized sensitivity specifications.



In your example you should use the measurement of the loudspeaker that is considered correct and not the one with errors.
View attachment 164062
About the incorrectness of the data specified by the manufacturer or problems with the measurement, makes up a large part in both threads about the F328Be speaker.

It is usually not easy to determine the average sound pressure level. Therefore, if the data is available, I would recommend using the average SPL from Pierre's website for the Revel F328Be (average of the frequency response from 300-10000Hz) or @MZKM (average of the frequency response from 300-3000Hz) .

View attachment 164060
Accordingly, the measurement shows the following f10/f6/f3 with 28/45/63 Hz.

This is still a way from the specified sound pressure levels

Revel is rightly criticized for it.




I would not be so uncritical about that. Legally, I agree with you completely; no one has acted unlawfully.

However, there are "unwritten laws" that many people adhere to, such as diagrams with 50dB scaling, indication of smoothing, frequency response measurements under free field conditions,...

Otherwise, you mislead consumers who cannot spend months reading up on the subject.

Or the next thing you know, you'll have a small bookshelf speaker with 90dB sensitivity and an f3 of 30Hz. The manufacturer could argue "Our research has shown that our speakers are usually placed in the corner of the room, so we raise the frequency response in the low frequency range by 18dB".

Come now,

If I buy $4 earphone, I don't expect any specification. It just needs to work
If I buy a $4,000 headphone, I do expect some kind of spec.

But look, I think I'm going to agree to disagree with you.

It seems to bother you that the manufacturer quoted spec doesn't match a measurers spec.
And you want them to somehow converge; presuming that will show some kind of consistency or honesty.
But even it a quoted spec by manufacturer matches that of a measurer, its still incomplete as far as what the spec actually tells me.

It doesn't tell me the shape of the LF roll-off, thus an anechoic F3/F6/F10 number is incomplete. The max SPL at F10 is also important too.
Furthermore, I would go to say that any full range speaker's bass spec isn't complete without quoting CEA 2010.

Any speaker can go down to 40Hz or 20Hz, but how loud can it do it play it? 60dB?

For instance, hitting 50Hz cleanly at 110dB peaks is much more impressive and enjoyable than getting all the way down to 20Hz, for instance small round D brand speaker that the manufacturer quotes (and EQ's it down flat down to 20Hz)

Erin's from Erinsaudiocorner.com measurements are even better than CTA2034, because he includes compression testing from 1V all the way to 102dB... I'm not holding my breath for all manufacturers to move to CTA2034...

 

[amper42]

There is no "standard".

This is the Revel F328Be, a top speaker from their stable. It's about US$8,000 for a single speaker.

Dennis’ speaker is less than $4,000 a pair.
So you could buy FOUR of Dennis’ speaker for a single single F328Be.

Any I digress. Revel is a company owned by Harman owned by Samsung. So as an audio company the access to more R&D than just about anyone, except Apple IMHO.

Here is the manufacturer's spec:

F328Be | 3-Way Triple 8" Floorstanding Loudspeaker

The Revel F328Be is the flagship floorstanding loudspeaker from our award-winning PerformaBe series. The F328Be includes a 1-inch (25mm) beryllium tweeter driven by massive 85mm dual ceramic magnets. The powerful all-new tweeter and 6th-generation ceramic-coated, cast-aluminum Acoustic Lens...

www.revelspeakers.com

Low frequency extension: 24Hz (-10dB); 26Hz (-6dB); 35Hz (-3dB)

Here is armirm's measurements taken with a Klippel NFS measurements:

Revel F328Be Speaker Review

This is a review and detailed measurements of the Revel F328Be floor standing speaker. I purchased a single unit through our company (Madrona) with kind discount from Harman Sales (I asked for a review sample from the PR group but was told "don't call us, we will call you."). The retail cost...

www.audiosciencereview.com

I've inserted the F3/6/10, compared to the red arrow line as the reference sensitivity.
View attachment 164058

To be clear, for those readers who are not loudspeaker designers, the NFS measurement is not wrong. And that quoted specification is not wrong. And no one is trying to mislead anyone.

It’s just different ways of representing data.

You realize @amirm updated the initial measurement above with an F6 of 29Hz for the Revel F328Be?

 

[Colonel7]

Having not hear Revels yet, I'd love to compare the F208 to the BMR Tower. Now that is a blind listening test I'd pay to participate in.

 

[amper42]

Having not hear Revels yet, I'd love to compare the F208 to the BMR Tower. Now that is a blind listening test I'd pay to participate in.

When my BMR Towers arrive in Dec I plan to compare them with REW in the same room with the Revel F328Be. My guess is both speakers will have a similar in room bass extension. I'm measuring F6 of 28Hz in my room with the F328Be. I will enjoy seeing how both speakers compare on the same REW chart in the same room. I was using the Sierra Towers with RAAL tweeter before the F328Be arrived. While the Sierra Towers sound great with subs, the F328Be offers a totally new world in bass extension and power.

The F328Be has significantly more speaker area than the BMR Tower. I would expect it to easily provide a greater SPL but the RAAL versus Be tweeter comparison might be even more interesting to me than the low end. I usually don't exceed 85dB for most listening sessions so I would like to see how close the BMR Tower compares at these lower SPL's.

 

[Juhazi]

It is very important to understand the difference of bass room response vs. various other methods. When reading advertisements and "details" you never really can trust your eyes, they come with grain of salt...

Here, my 10" closed box speaker's nearfield (raw, no baffle loss comp) vs. room spot measurements, just as an example. And yes, bass sounds very good and deep. Easy to set up with Hypex FA...

 

[Shazb0t]

When my BMR Towers arrive in Dec I plan to compare them with REW in the same room with the Revel F328Be. My guess is both speakers will have a similar in room bass extension. I'm measuring F6 of 28Hz in my room with the F328Be. I will enjoy seeing how both speakers compare on the same REW chart in the same room. I was using the Sierra Towers with RAAL tweeter before the F328Be arrived. While the Sierra Towers sound great with subs, the F328Be offers a totally new world in bass extension and power.

The F328Be has significantly more speaker area than the BMR Tower. I would expect it to easily provide a greater SPL but the RAAL versus Be tweeter comparison might be even more interesting to me than the low end. I usually don't exceed 85dB for most listening sessions so I would like to see how close the BMR Tower compares at these lower SPL's.

How did the overall sound quality of the Sierra RAAL Towers with subs compare to the F328 at your usual 85dB or less SPL?

 

[amper42]

How did the overall sound quality of the Sierra RAAL Towers with subs compare to the F328 at your usual 85dB or less SPL?

Probably best not to turn the BMR Tower thread into a thread for Sierra Towers. If you start a private conversation with me I'll try to answer your question. Thanks!

 

[Dyabolikal]

Does anyone know if a BMR tower flat pack will be available in the future? I tried searching various threads but haven't found anything yet. Thanks!

 

[Dennis Murphy]

Does anyone know if a BMR tower flat pack will be available in the future? I tried searching various threads but haven't found anything yet. Thanks!

I don't have any plans to offer the tower as a kit. One reason is simply protection of intellectual property. That's why the BMR monitor kit is only available in the Scanspeak version.

 

[ironhorse128]

@Dennis Murphy May I ask what are the chances that the BMR tower can be bought in Europe?

 

[Dennis Murphy]

@Dennis Murphy May I ask what are the chances that the BMR tower can be bought in Europe?

I'm afraid they're approximately zero. One reason is shipping cost--I'm too small an operation to obtain favorable international shipping rates. The other is my reluctance to place a speaker in a location where rectification of any shipping damage or performance of warranty service isn't practical.

 

[sweetchaos]

I'm afraid they're approximately zero. One reason is shipping cost--I'm too small an operation to obtain favorable international shipping rates. The other is my reluctance to place a speaker in a location where rectification of any shipping damage or performance of warranty service isn't practical.

What about Canada?

 

[Doodski]

What about Canada?

I thought Obama spread the word around in his public address to give us Canucks equal shopping privileges.

 

[Dennis Murphy]

What about Canada?

We could do that, but it will be expensive, and I don't know what kind of duties would be involved.

 

[sweetchaos]

We could do that, but it will be expensive, and I don't know what kind of duties would be involved.

Pretty simple to calculate, we just need to know it's value in CDN.
Duties are typically it's 12% in BC, just like taxes.
So for a US$3700/pair =>CDN$4600/pair, it would be CDN$550 or so in duties.
Duty payment is made at the border if you're driving across yourself (this way you save on shipping, of course), otherwise something must be arranged when shipping directly to Canada.

Duty calculator:

Estimate duty and taxes

Canada Border Services Agency Duty and Taxes Estimator

www.cbsa-asfc.gc.ca