Revel F328Be Speaker Review

[amirm]

One thing I can do is optimize the Revel F35 which I still have (I bought it myself). That one is so much more manageable to play with than this monster. The hitch is that I have an incredible backlog of speakers to test all of a sudden. So need to go through them before spending time just playing with the system.

 

[FrankF]

In 2008 Kevin Voecks told Larry Greenhill in a interview for Stereophile compairing the Salon2 versus Studio2:

The Salon2 moves more air and has greater output, particularly in the bass. The Salon2's three 8" woofers have a combined area equivalent to a 14" woofer, but the heat generated is spread out among three voice-coils. This means that you won't get the heat buildup that leads to dynamic compression. (As voice-coils heat up, impedance goes up and leads to a mismatch in a speaker's filter network.) The Salon2 is more resistant to dynamic compression than the Studio2 because it has more drivers to dissipate the heat. The Salon2 also has a smaller midrange than the Studio2. This leads to a better match between tweeter and midrange drivers, helping control the Salon2's off-axis response.

Seems to imply the 3 woofers in the Salon2 are superior performance wise to dual subwoofer augmentation. Having recently purchased a "pre-owned" pair of Salon2's I can confirm this using the miniDSP SHD and Dirac. This compared to a pair of Monitor Audio Silver 8's and 2 JL Audio f110 subs with Dirac.

This is my own subjective opinion, however, it is confirmed by my wife's greater complaint ratio.

 

[beagleman]

I find I change the level of my Velodyne DD18 depending on the content (there's a remote with handy presets). The bass content on anything before the last 10 years varies dramatically. It does put the listener in the position of being a mix engineer.

But that doesn't have to do with subs v. floorstanders per se, only that with most floorstanders you're not hearing much below 35 hz, no matter how you eq it.

I had an older EV huge cabinet speaker., (EV SIX) with an 18" woofer, and it would equal most good subs, and you just had to live with how bad or how great some stuff was mixed.

A lot of TV shows and news casts and commercials, have huge bass boosts in the 30 hz range, no idea why, but voices, certain sound effects and so on or newscasters bumping the desk and so on would create this huge "Boomp" sound often.

I think most towers do not do this stuff justice...lol

 

[andreasmaaan]

As I explained at the outset, I went through a series of steps to optimize the low frequency accuracy. This reached an asymptotic level and hence my guess of 1 dB or so which applies to that shelving.

Thanks Amir. I understood that you went through optimisation and reached an asymptotic level, I just wasn't sure how you translated that to a 1dB margin.

Whatever way we look at it though, it seems that we can be very confident that the bass response we have here is essentially correct, at least above 30Hz.

 

[q3cpma]

Simple: laws of physics. Measurements are showing anechoic response, not what a speaker does in a room. As soon as you place a speaker close to any walls, those walls focus the bass energy forward and you get more bass. Then other walls add to it causing destructive and constructive interference which we call room modes. Take your speaker outdoor and listen to it. The amount of bass it produces will shrink way down and will not sound anything like what you hear in your room.

Question: won't group delay skyrocket if you need room modes (and not only boundary gain) to reach the desired LF level? Even then, my intuition is that group delay may be proportional to how much boundary gain you need to add to reach it.

 

[amirm]

Another option would be to buy a hand truck. Lets donate to the cause!
https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thanks a bunch but I have a few of those and they won't help. For measurements, the speaker needs to be lifted 5 feet high and then slid onto the measurement platform. These speakers are heavy enough to move. Lifting them that high and then carefully putting them on a platform is out of the question. It is not like they have handles and such.

Fortunately I solve the above problem with an expensive purchase: https://www.amazon.com/gp/product/B0054M082Y/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

$600 dollars later, I am able to lift speakers with ease. Getting them from the platform to the measurement stand is tricky but doable. Without the above, it would have been impossible to measure this speaker. Son in general, I am good with measurement ability.

The problem is listening. I would have to first pack the speaker in its box to move with any dolly as to not scratch it. And then pull up the speaker up the stairs supporting not only its weight, but the addition of the dolly! Worse yet, the stairs we have are built out of wood and are open structure. Kind of like this:

Except ours goes to a landing half way up and then rotates and keeps going.

No way I can let the dolly drag against those stairs.

Wish I had known what I know now when we remodeled our house! This loft was supposed to be my photography studio, not audio lab and listening area.

 

[st379]

For many speakers, yes, the NFS computation is more accurate than anechoic chamber. Indeed the system is also sold to be used in anechoic chamber to improve its accuracy.

For these speakers, until we have a gold standard (speaker measured outdoor away from any reflections for countless feet), we don't know. Both systems have accuracy errors. I just don't know enough to say for sure.

I have asked Klippel about this and they don't have an answer but stick by NFS working correctly and producing the right response.

Simple: laws of physics. Measurements are showing anechoic response, not what a speaker does in a room. As soon as you place a speaker close to any walls, those walls focus the bass energy forward and you get more bass. Then other walls add to it causing destructive and constructive interference which we call room modes. Take your speaker outdoor and listen to it. The amount of bass it produces will shrink way down and will not sound anything like what you hear in your room.

Thank you. I appreciate the explanation.

But is not a speaker with more bass always has more bass even in different rooms without any room treatment?

 

[Dimifoot]

Here is Dr. Toole in the very pages you listed:

You are quoting from the previous version of the book, you also need to get the new edition, just like @Frank Dernie

At the "What then" question, in this previous edition that you are quoting from (yes I have them both), Toole gives the answer:

"The answer is that one must start with real acoustical measurements—full complex data: amplitude and phase or impulse response—between each sub- woofer location and each listener location."
And it goes on...

No one here is using the technique described in those pages.

Dot be so sure, some do ...Not many use similar techniques, sure, and that's unfortunate for an objectivists forum.

Of course its impossible to implement them with simple 2 channel DACs. Thats why these components are so vintage, impossible to reproduce at SOTA level. How can you claim SOTA performance when the system can't reproduce half of the first octave, and the first three octaves can't follow at Reference Level after equalisation? This is not SOTA, it's a compromise like any other. And its audible.

And there many alternatives, like the one @Sancus mentioned

There is actually plenty of information on the web about how to do this using free software and a miniDSP.

Multi-Sub Optimizer
Tutorial using REW + MSO + MiniDSP.

It's far from simple and not for the faint of heart though. There is a reason so many people are interested in automated bass management. The manual process requires many hours of work and a good understanding of the tools.

Trinnov also has a manual way of implementing multisub using the Active Crossover Menu in a similar way as SFM, and Dirac has now an automated version. The Monoprice processor can employ it, yes the one that wasn't recommended here- unfortunately there is more focus in the 5th decimal of THD+Noise instead of what really matters in Sound Reproduction in rooms, and not through headphones.

 

[DDF]

When comparing older Revel speakers using the same test set up, the older speakers mostly had a frequency response boost below 200Hz, compared to this speaker.

Given the long wavelengths involved and intended placement use, Revel can't justify that this design gets more boundary reinforcement than the previous speakers measured.

Revel can't think that both frequency responses are ideal targets. My guess is that this is a case of "loud sells" so they sacrificed some bass extension and level for sensitivity.

 

[JohnBooty]

You know, it's funny.

My subwoofer comment was vague enough to mean various things, I suppose, and of course lots of people decided it meant something heretical.

Relax, I don't have any opinions on audio that are so interesting. Although the tendency to dogpile on ASR can be a bit interesting.

We shouldn’t have to explain again and again in an objectivists audio science forum, why multisub+room Eq is mandatory for proper bass reproduction in rooms.

Where is the evidence that integrated woofers produce better bass than subwoofers? This isn't sarcastic, I'm truly curious. Because as far as I know, it's the opposite. Subwoofers require more work and you need more than one for the best results, but as far as I understand it, it is physically impossible to produce bass on the same level as this with ANY two speakers no matter how "high-end".

First, I should start by saying that my main music system has dual subs and EQ.

There is no disputing that if you want accurate in-room deep bass, such as the immaculate waterfall graphs down to ~17hz that you linked to, then you need to bust out the multiple subwoofers. It's basic physics. There's no other way. As @Dimifoot wrote, I too hope that it is basic foundational knowledge in this hobby or at least on this forum.

That all said...

That said, a customer buying $16,000+ speakers probably doesn't want to be told "oh you also need a modern room EQ system, DSP, and 4 other boxes to get good results". Even though that is probably what they do, in fact, need.

Need? I certainly would not agree that subs are necessary or even ideal for "most" music.

Strong bass down to the 30-40hz range is deep enough for nearly all music, and a lot of music doesn't need bass reproduction that deep.

Finally, there's the matter of budget. A multisub+roomEQ setup with subwoofers capable of accurate deep bass is not cheap. It certainly can be done cheaper, particularly if you're going DIY or buying used, but multisubs+EQ is generally going to start out at around $1K at retail and obviously can cost much more.

Unless their overall budget is so large that a grand or two is insignificant, most people would be generally better off spending an extra grand on their treble and midrange (you know, where the music actually lives) than dumping all that money into the bottom octave alone.

As @amirm said, a speaker like this Revel that can cover that range and do it well, is going to sound great for nearly everything.

EQ

As for EQ? Well, I don't think it belongs in this discussion. If you want accurate in-room response, it is a requirement, and that is particularly true for bass. But that is equally true either with or without subwoofers.

 

[Vini darko]

Do any members have these speakers? Could you show an in room measurment to put this bass chat to bed?

 

[Valentin R]

The 328 features a newer and slightly improved waveguide. I don’t remember if it uses the same tweeeter.

It’s a different tweeter

 

[Dimifoot]

Strong bass down to the 30-40hz range is deep enough for nearly all music, and a lot of music doesn't need bass reproduction that deep.

You do realize that when we accept “deep enough” and “a lot of music doesn’t need” etc, this is not SOTA anymore?

You do, I know, that’s why your

main music system has dual subs and EQ.

 

[testp]

Where's the panther @amirm?

im guessing the panther was blown away...

 

[ctrl]

Namely, Klippel system is self-checking and provides a comparison of measured response versus computed one (both projection of soundfield and removal of reflections). Here is that result for reference axis:

@amirm, thank you for your efforts.
Does z= not specify the distance of the calculated soundfield? Does the frequency response change when the soundfield is calculated for 4m (minimizes the phase errors due to the speaker enclosure dimensions and the arrangement of the drivers and ports)?

The only error I see there is down below 30 Hz where our response falls lower than real measurement. So maybe that should be 65 dB vs 60 dB.

Would also see it that way.
However, it would be theoretically possible that in the range below 30Hz chassis and BR-ports would behave phase-inverted and the sound pressure would be at a similar level. Then a very steep sound pressure drop would be expected and your NFS measurement would fit.

 

[oldsysop]

They buy toy speakers and then find they have to buy a separate woofer. Yes, the D&D 8c is also an expensive joke.
Salon2 and F328Be do not need a subwoofer.

 

[McFly]

While I don't have these speakers, a very quick & rough modelling of 3x 8" woofers in UniBox (assuming SB Acoustics SB23CACS45-4 or similar) in a 140L cabinet (assuming 158L internal minus the mid cab and the ports volume based on guessed internal measurements of the speaker) concludes a 29hz F3, sacrificing a bit of port air speed. I did not find the diameter of the 328Be's ports so I gussed 7.5cm or ~3inch x2

Sure, this is not the Revel F328Be, but more a model of what 3x SBA 8" woofers will do in a large cabinet.

This would be my estimate of this speaker "in-room" with some boundary loading, shown in green.

I am sure the F328Be will hit at least 35 or 40hz -3dB in your house/room, anechoic chamber or measurements be damned. These things will be amazing speakers.

One day I wish to own some, but for now, I will try and build them instead

 

[amirm]

You are quoting from the previous version of the book, you also need to get the new edition, just like @Frank Dernie

I have the new edition as well. Reference was made to the old text so I quoted that. That text is identical in the third edition:

 

[RickSanchez]

Congrats on reaching the 100 speaker milestone Amir! Amazing work, you've provided (another) great service to the audio community.

 

[amirm]

Dot be so sure, some do ...Not many use similar techniques, sure, and that's unfortunate for an objectivists forum.

SFM is patented so the other schemes are not the same. Let's have a show of hands for people who advocated DSP and are using computational optimization of these three parameters:

I don't know of other systems with the third one as highlighted.

Remember please, Dr. Toole is a friend and what you are reading, I have heard him say first hand.

Multiple subs are powerful in the way they provide even response in multiple seats. But you need proper and effective EQ to do it right. It is not "just buy a bookshelf and add subs" kind of solution.

In addition, remember that proper placement of mains speakers also alleviate room modes. By placing the speaker at 1/4 wavelength positions for example, you get rid of cancellations due to some room modes. Here is Dr. Toole from his in-person presentation at CEDIA:

So there is no confusion: you can do well with subs but be prepared for a lot of optimization and experimentation.