Revel F328Be Speaker Review

[phoenixdogfan]

No matter how amazing the Revel Beryllium speakers may sound and no matter what Revel says in their marketing spiel, it is exceedingly unlikely that the sound quality is influenced to any significant degree by the use of beryllium for the tweeter dome. Substantive differences in sound quality, for the beryllium speaker vs. a similar speaker in the Performa3 line, are the cumulative effect of numerous design differences between the two speakers. With respect to the F328Be this is obviously true given that in the Performa3 line there aren't any speakers with three 8" woofers. But even if you compare the F228Be to the F208, various differences will be found that will be much better explanations for any differences in how they sound, vs. the difference in the metal used for the tweeter dome.

The use of ultra-exotic materials in loudspeaker design has long been a successful practice, but more from a marketing perspective than an engineering perspective. Revel is no more and no less prone to this successful marketing practice than any other loudspeaker manufacturer. People (audiophiles especially) are impressed by the use of exotic aerospace materials in loudspeakers. Relative to a given stiffness, a dome made of beryllium will be less massive than an aluminum dome. A somewhat more powerful motor is therefore needed with an aluminum dome. This implies either a stronger Bl value or else greater wire length in the gap, either of which also provides the additional damping required by the more massive aluminum dome. All in all the aluminum dome tweeter will be slightly lower in efficiency and sensitivity. Beyond this, there is not likely any significant difference between beryllium and aluminum, as it applies to loudspeaker tweeters. I doubt whether anyone designing a speaker has encountered any difficulty finding tweeters with adequate efficiency and sensitivity. In general, tweeters are several dB more sensitive than the other drivers and need to be padded to bring their sensitivity in line with the other drivers. This is typically true even for tweeters that use non-metallic domes.

As to the question of whether there is any moral dilemma over the use of beryllium, the best answer is simply "no". The use of beryllium in aerospace and other industries is nowadays fairly common. And even if the use of beryllium weren't common, there are lots of other commonly used materials that are vastly more hazardous, that most everyone simply accepts as a fact of modern life. The common and unavoidable practice of storing fuel and highly toxic chemicals in facilities located within reach of urban centers poses a vastly greater risk to public health.

If what you really want in a speaker is for it to sound as correct as possible, objective measurements are the only way. Something that isn't pointed out nearly as often as it should be is that whenever there is a debate over which speaker (among several) is more correct, there is just one way that a debate of this sort can be settled, which is by comparing the objective measurements. Even if 90% of listeners prefer the sound of speaker A over the sound of speaker B, the only way to ascertain which speaker is more correct is by comparing objective measurements. If the objective measurements are so similar that it isn't apparent which speaker is more correct, then there isn't any genuine reason to think that either of them is more correct than the other.

The more I research this, the more convinced I am that either the 208 of the 226be is the sweet spot in the Revel line.

 

[Martini]

Lithium is also precious element and is nasty to mine and to manufacture into batteries. Where is the justified call to end usage of them in electric cars, where their consumption is high and usable life short; especially in comparison to a beryllium tweeter.

 

[Robbo99999]

Lithium is also precious element and is nasty to mine and to manufacture into batteries. Where is the justified call to end usage of them in electric cars, where their consumption is high and usable life short; especially in comparison to a beryllium tweeter.

Yeah, that is a problem, I don't think electric cars are the answer due to that fact. And it would dwarf the beryllium issue.

 

[MaxBuck]

Lithium is not a "precious element;" it's the 33rd-most prevalent element in nature. But we're getting pretty far afield here; it sure wasn't my intent to twist anyone's shorts. If anyone wants to put beryllium tweeters in their speakers, they won't hear any more from me.

 

[Descartes]

We are a long way from discussing the sound of this great speaker!

 

[RichB]

The F28Bes do appear to be easier to drive above 400 Hz than the F208s.

- Rich

 

[phoenixdogfan]

Lithium is not a "precious element;" it's the 33rd-most prevalent element in nature. But we're getting pretty far afield here; it sure wasn't my intent to twist anyone's shorts. If anyone wants to put beryllium tweeters in their speakers, they won't hear any more from me.

Along with Hydrogen and Helium, it was one of the only three elements synthesized out of the big bang.

 

[Senior NEET Engineer]

The more I research this, the more convinced I am that either the 208 of the 226be is the sweet spot in the Revel line.

Their product development manager thinks the F206 is sweet spot

 

[richard12511]

@napilopez , in the 8351b thread(I think?) you posted a dispersion width comparison between that speaker and the Salon2. Did you do this by digitizing the Salon2 measurements from somewhere? and, could you do the same with the Salon2 and the F328Be? I'd be really curious to see how the off axis curves look on the same scale and graph.

 

[Vhond]

Their product development manager thinks the F206 is sweet spot

Why this one?

 

[echopraxia]

Their product development manager thinks the F206 is sweet spot

Then they should be nowhere near the speaker industry. I’ve owned the F206, and sold it shortly after because it is a much more flawed speaker than their higher end lines, and even more flawed than some of their 'lower end' products like the M16 and F36. The F206 treble is not so great, and this not only very audible but shows up in spins I’ve seen. Anyone (from Harman or otherwise) saying the F206 is the “sweet spot” from Revel either should get their hearing checked, or their sight checked (and their ability to read spin charts). Are you sure they didn’t say F226Be? That would make much more sense.

I think you could far more easily argue that the M106 is a better price/performance “sweet spot” than the F206, since it’s measurements show it doesn’t have the treble problems the F206 has, and in fact measures overall much better than the F206 aside from bass power.

But the fact that anyone thinks the F206 with its flaws could be a “sweet spot” is a perfect example of why there is no such thing as a “sweet spot”. It depends on how sensitive your ears are to subtle flaws, how perfect you really want your speakers to get, how much dynamic range you want your speakers to be able to effortlessly express without compression, how large your room is you want to fill with music, etc.

 

[Absolute]

Regarding the use of Beryllium in diaphragms I don't agree that it's marketing fluff. The lightness, stiffness, higher break-up point and better damping leads to faster decay and better transient response. Whether or not it makes sense for small domes or not is not for me to say, but it makes a clear difference in compression drivers where the domes are larger.
In many compression drivers the response above around 9-12 khz is mainly just resonances, not clean response. Beryllium has the potential to expand that limit greatly.

Here's an illustration from Sigfried Linkwitz about decay vs frequency;

Decay is like a noisefloor that varies greatly depending on frequency. After experimenting a bit with a compression driver Equalized to flat response vs normal compression driver with same response I'm positive that frequency response alone don't tell the full story.

 

[Shazb0t]

Regarding the use of Beryllium in diaphragms I don't agree that it's marketing fluff. The lightness, stiffness, higher break-up point and better damping leads to faster decay and better transient response. Whether or not it makes sense for small domes or not is not for me to say, but it makes a clear difference in compression drivers where the domes are larger.
In many compression drivers the response above around 9-12 khz is mainly just resonances, not clean response. Beryllium has the potential to expand that limit greatly.

Here's an illustration from Sigfried Linkwitz about decay vs frequency;

View attachment 134663
View attachment 134664

Decay is like a noisefloor that varies greatly depending on frequency. After experimenting a bit with a compression driver Equalized to flat response vs normal compression driver with same response I'm positive that frequency response alone don't tell the full story.

Wouldn't this show up in the frequency response?

 

[Senior NEET Engineer]

Then they should be nowhere near the speaker industry. I’ve owned the F206, and sold it shortly after because it is a much more flawed speaker than their higher end lines, and even more flawed than some of their 'lower end' products like the M16 and F36. The F206 treble is not so great, and this not only very audible but shows up in spins I’ve seen. Anyone (from Harman or otherwise) saying the F206 is the “sweet spot” from Revel either should get their hearing checked, or their sight checked (and their ability to read spin charts). Are you sure they didn’t say F226Be? That would make much more sense.

I think you could far more easily argue that the M106 is a better price/performance “sweet spot” than the F206, since it’s measurements show it doesn’t have the treble problems the F206 has, and in fact measures overall much better than the F206 aside from bass power.

But the fact that anyone thinks the F206 with its flaws could be a “sweet spot” is a perfect example of why there is no such thing as a “sweet spot”. It depends on how sensitive your ears are to subtle flaws, how perfect you really want your speakers to get, how much dynamic range you want your speakers to be able to effortlessly express without compression, how large your room is you want to fill with music, etc.

One difference is that Revel uses controlled blind testing

 

[echopraxia]

One difference is that Revel uses controlled blind testing

No. The F206 treble resonance/peaking shows up in Revel's own measurements, and was audible to blind listeners in blind tests I performed with it.

Anyone from Harman saying that the F206 is the 'sweet spot' of Revel speakers is either lying to you, or unable/unwilling to read their own measurements of their speakers -- where it is clear that both the (cheaper) M106 and (more expensive) F208 are significant steps up in quality and lack of flaws:


F206:

F208:

M106:

F226Be:

 

[Lsc]

No. The F206 treble resonance/peaking shows up in Revel's own measurements, and was audible to blind listeners in blind tests I performed with it.

Anyone from Harman saying that the F206 is the 'sweet spot' of Revel speakers is either lying to you, or unable/unwilling to read their own measurements of their speakers -- where it is clear that both the (cheaper) M106 and (more expensive) F208 are significant steps up in quality and lack of flaws:


F206:
View attachment 134725
F208:
View attachment 134728


M106:
View attachment 134726


F226Be:
View attachment 134727

I agree with you 100%. But I don’t really think anyone at Revel would make such a claim unless the term “sweet spot” means different things to different people.

 

[richard12511]

No. The F206 treble resonance/peaking shows up in Revel's own measurements, and was audible to blind listeners in blind tests I performed with it.

Anyone from Harman saying that the F206 is the 'sweet spot' of Revel speakers is either lying to you, or unable/unwilling to read their own measurements of their speakers -- where it is clear that both the (cheaper) M106 and (more expensive) F208 are significant steps up in quality and lack of flaws:


F206:
View attachment 134725
F208:
View attachment 134728


M106:
View attachment 134726


F226Be:
View attachment 134727

I would say the F208 + sub seems like the sweet spot. That's the point where the measurements get near perfect. The extension isn't near as good as the Salon2, and the dispersion isn't as wide, but it may actually be a bit smoother.

At some point it comes down to how much are you willing to pay for that last 5% of performance, so I think everyone's sweet spot will be different.

 

[Χ Ξ Σ]

Look at the difference in bass directivity between 100-200Hz among the F208, F228Be and F328Be. Apparently the higher up the model, the better the bass directivity. I assume that bass directivity matters, otherwise what is the point of developing the W371 and D&D 8c. I understand the bigger F328Be should have lower bass directivity. I was amazed that the F228Be, being the exact same size and layout as the F208, also beats F208 in bass directivity. The only difference I can find in the specs are crossover points, 260Hz for the F228Be and 270Hz for the F208. What else causes the difference in bass directivity?

 

[echopraxia]

I agree with you 100%. But I don’t really think anyone at Revel would make such a claim unless the term “sweet spot” means different things to different people.

Perhaps, but I am not aware of any definition of “sweet spot” that fits a performance outlier in the negative direction. Usually it’s either an outlier in the positive direction, or some arbitrary point chosen on a continuous curve of price vs performance. But in the F206 case, it seems to be one of Revel’s most underperforming speakers in the sense that both adjacent products in the Performa3 line (the M106 and F208) seem to be better speakers! So this makes the F206 the exact opposite of any definition of “sweet spot” I’m aware of.

Now, the F206 is definitely in a physical size form factor sweet spot for a lot of people (though this is of course subjective), as is the identically sized F226Be. Perhaps this is what the person was referring to, if it was a time prior to the release of the PerformaBe series.

 

[echopraxia]

Look at the difference in bass directivity between 100-200Hz among the F208, F228Be and F328Be. Apparently the higher up the model, the better the bass directivity. I assume that bass directivity matters, otherwise what is the point of developing the W371 and D&D 8c. I understand the bigger F328Be should have lower bass directivity. I was amazed that the F228Be, being the exact same size and layout as the F208, also beats F208 in bass directivity. The only difference I can find in the specs are crossover points, 260Hz for the F228Be and 270Hz for the F208. What else causes the difference in bass directivity?
View attachment 134816View attachment 134817View attachment 134818

That is very interesting! I wonder how they achieved this too.

I have also often wondered if directivity of bass is much more important than it’s currently thought to be in terms of bass sound quality and tactile “impact”. Perhaps it explains why many bookshelf speakers with deep bass response often still do not sound “big” like these big towers often do, and as you say could explain the purpose of products like W371 and D&D 8C reportedly sounding amazing.