Revel M16 Speaker Review

[stren]

I can pick up an S16 at a later date and test.

Nice - how would you test on the klippel? Would you have to add a large sheet of thick plywood to mimic the wall mount and boundary effect or can the Klippel take that into account?

 

[QMuse]

Intellectually I'd also be interested in the S16 and C25 comparison to the M16 when assuming subwoofers. Practically this is probably too much focus on revel vs more coverage on other brands.

S16 is basically the M16 in a less deep enclosure with no port and 1.8KHz crossover, plus a less boxy design to presumably try and reduce the boundary effect. The lower crossover might help the woofer strain and if you were going to block the ports on the M16 as you were using them close to a wall anyway then the S16 might be even better due to the boundary improvement. Yes you would lose the low end, but presumably only in the region that a sub could takeover.

The C25 - looks like it could be rotated and used as a bookshelf which would also suit it's tweeter waveguide better by the look of things. Like the S16 it's sealed but with two 5.25" woofers which would reduce the strain at crossover. Potentially it may behave more like the F35 until lower frequencies. Same again on the low end being weak compared to the M16, but presumably again covered by a sub.

S16 has been designed to be mounted on-wall, so not really a true HiFi speaker which can be put on a stand but more of a home cinema LCR speaker.

 

[amirm]

Nice - how would you test on the klippel? Would you have to add a large sheet of thick plywood to mimic the wall mount and boundary effect or can the Klippel take that into account?

Yes. The cool thing is that the sheet doesn't have to be very large as diffraction around the edges of the sheet will be ignored by the analyzer.

Could also measure it without the backer board and not worry about the low frequency gain that provides.

 

[stren]

S16 has been designed to be mounted on-wall, so not really a true HiFi speaker which can be put on a stand but more of a home cinema LCR speaker.

Sure - I get your point when a wall mount speaker is very different to a hifi speaker and has different drivers etc etc. But in this case the M16 and S16 are almost identical with the exception of the port. I guess my thought is, that when you are forced to have a traditional hi-fi speaker that close to the wall is it better or worse to buy a version with the same drivers etc, but that is designed for being placed up against the wall? That seems like a question worth answering to me. It seems like the S16 should actually do better for hi-fi in this scenario. HT speakers definitely have the advantage of being able to roll off earlier as a sub is assumed, but if you assume a sub for bookshelves too and assume a plugged port then the scenario is not very different.

 

[QMuse]

Sure - I get your point when a wall mount speaker is very different to a hifi speaker and has different drivers etc etc. But in this case the M16 and S16 are almost identical with the exception of the port. I guess my thought is, that when you are forced to have a traditional hi-fi speaker that close to the wall is it better or worse to buy a version with the same drivers etc, but that is designed for being placed up against the wall? That seems like a question worth answering to me. It seems like the S16 should actually do better for hi-fi in this scenario. HT speakers definitely have the advantage of being able to roll off earlier as a sub is assumed, but if you assume a sub for bookshelves too and assume a plugged port then the scenario is not very different.

I can certainly agree with you that a small sealed box have better chances to sound well when coupled with a sub then a small ported box where various compromise were made to extend bass which anyhow won't be enough.

Speaking of that, I am not a fan of bass-reflex boxes in general as I believe TL design is a better solution to extend LF response of a sealed box. If you need more bass than get a sub(s), for music preferably also sealed. This is of course my personal opinion, YMMV.

 

[Haint]

Nice - how would you test on the klippel? Would you have to add a large sheet of thick plywood to mimic the wall mount and boundary effect or can the Klippel take that into account?

Directly wall mounting any speaker will produce significant nulls that vary with the depth of the cabinet, but it's usually in the 300-500Hz region. I'm not sure if putting a false backing behind it will show the same effect on the Klippel, but you definitely compromise performance for the aesthetic and space savings of wall mounting. It may be a worthwhile trade off for a bedroom or living room (which is how I use mine), but in a critical space I'd use it on a stand like you would an M16, not a wall mount. A freestanding S16 sounds very similar to the M16 when they're crossed with a sub.

 

[thewas]

The null/SBIR when placed directly at the wall is less pronounced though (due to the loudspeakers getting already a bit directive) and acoustically problematic then the usual one in the bass when placing them the usual one meter from it:

Of course when well correctly crossed with a sub you have more good options as you place both such to have their front wall SBIRs outside from the operating region:

 

[lonewolf]

The C25 - looks like it could be rotated and used as a bookshelf which would also suit it's tweeter waveguide better by the look of things. Like the S16 it's sealed but with two 5.25" woofers which would reduce the strain at crossover. Potentially it may behave more like the F35 until lower frequencies. Same again on the low end being weak compared to the M16, but presumably again covered by a sub.

I have the C25 at home and have been happy with it. I also have the F35s and tonally they sound the same. I have been really curious about the vertical waveguide tho, I would have assumed a horizontal one would've been better but that would put the drivers a bit further apart. I would expect the vertical waveguide to put more energy towards the floor and ceiling. So far I don't seem to be having any issues with it and REW measurements with it are fine, so I don't worry about it.

 

[stren]

Directly wall mounting any speaker will produce significant nulls that vary with the depth of the cabinet, but it's usually in the 300-500Hz region. I'm not sure if putting a false backing behind it will show the same effect on the Klippel, but you definitely compromise performance for the aesthetic and space savings of wall mounting. It may be a worthwhile trade off for a bedroom or living room (which is how I use mine), but in a critical space I'd use it on a stand like you would an M16, not a wall mount. A freestanding S16 sounds very similar to the M16 when they're crossed with a sub.

Yeah for those of us in tiny one apartments (San Francisco for me), we can be very limited in placement options. In an ideal world I'd have towers that were spaced appropriately to the walls. In reality for this apartment my only choice is to have bookshelf sized speakers placed on top of a built in cabinet that can be at max 0-5" away from wall, then add subs placed wherever I can hide them and fix the resultant low end mess with DSP.

 

[QMuse]

Yeah for those of us in tiny one apartments (San Francisco for me), we can be very limited in placement options. In an ideal world I'd have towers that were spaced appropriately to the walls. In reality for this apartment my only choice is to have bookshelf sized speakers placed on top of a built in cabinet that can be at max 0-5" away from wall, then add subs placed wherever I can hide them and fix the resultant low end mess with DSP.

2-5" from the wall is actually excellent position for bookshelves.

 

[Haint]

The null/SBIR when placed directly at the wall is less pronounced though (due to the loudspeakers getting already a bit directive) and acoustically problematic then the usual one in the bass when placing them the usual one meter from it:

View attachment 55599

Of course when well correctly crossed with a sub you have more good options as you place both such to have their front wall SBIRs outside from the operating region:

View attachment 55600

I'll be the first to admit I have little understanding of the physics and science behind it, but stand mount was Dr. Toole's recommendation on how to deploy JBL Arena 120's which are a similar slim cabinet quasi-bookshelf that's technically designed for wall mounting. Logically, I'm guessing a direct wall mount is guaranteed to experience the full brunt of the SBIR cancelation where as away from the wall there is a likelihood of other interferences reducing the effect. That's pure conjecture on my part though.

 

[thewas]

As said the closer to the front wall the cancellation frequency gets higher were most loudspeakers are more directional and thus don't radiate so much energy to their rear. If someone can place his loudspeakers more than 2 meters from the front wall then the primary SBIR frequency on the other side gets so low that it doesn't matter much, but most people don't have so much space.

 

[bigjacko]

The null/SBIR when placed directly at the wall is less pronounced though (due to the loudspeakers getting already a bit directive) and acoustically problematic then the usual one in the bass when placing them the usual one meter from it:

View attachment 55599

Of course when well correctly crossed with a sub you have more good options as you place both such to have their front wall SBIRs outside from the operating region:

View attachment 55600

What is the best distance range? Is it as close to the wall or something like 5 cm to 15 cm? Will the port behind the speakers get blocked if the distance is too short?

 

[thewas]

Something like 5 cm to 20 cm is usually fine and enough not to change the behaviour of the port.

 

[stren]

Personally I'm blocking my LS50 rear facing ports. But yes once you are this close, my question was if you are using the M16 that close to the wall, is it better to use the S16 given that they are almost identical, but presumably the S16's slopey sides might provide boundary benefits.

 

[Koeitje]

How do you guys think the M16 compares to what I have right now? Only on-axis unfortunately...

 

[Absolute]

This is Listening Window, Early Reflections and Sound Power responses magnified. What 5kHz bump are we speaking about?

View attachment 52971

Just reading through the thread and looking further into this peak around 5khz.
This is what the designer says about it in the M106;

"On axis, with no averaging, the peak in the tweeters response 4.5kHz -6.5kHz is brought more clearly into focus. Kevin Voecks reports this is not a resonance “but is due to a transition in the waveguide from limiting dispersion to increasing it, and from diffraction”. The peak reduces significantly at 15 degrees off-axis and becomes smaller at wider angles. "

https://hometheaterhifi.com/reviews...ookshelf-monitor-loudspeaker-review-part-one/

 

[Koeitje]

How do you guys think the M16 compares to what I have right now? Only on-axis unfortunately...
View attachment 56092

I just got M106's and didn't do a 1 on 1 comparison, I just swapped them out and....they sound so similar its actually nuts. The only difference I notice is that the low-end is different, not sure what the difference is. The Revel's seem to less boomy, but also don't go as low? Does port tuning interact with the room?

 

[QMuse]

Just reading through the thread and looking further into this peak around 5khz.
This is what the designer says about it in the M106;

"On axis, with no averaging, the peak in the tweeters response 4.5kHz -6.5kHz is brought more clearly into focus. Kevin Voecks reports this is not a resonance “but is due to a transition in the waveguide from limiting dispersion to increasing it, and from diffraction”. The peak reduces significantly at 15 degrees off-axis and becomes smaller at wider angles. "

https://hometheaterhifi.com/reviews...ookshelf-monitor-loudspeaker-review-part-one/

I wanted to stress out that peak az 5kHz, while being quite noticeable in the on-axis response is barely visible in LW, ER and SP responses.

 

[ctrl]

This is what the designer says about it in the M106;
"Kevin Voecks reports this is not a resonance “but is due to a transition in the waveguide from limiting dispersion to increasing it, and from diffraction”. The peak reduces significantly at 15 degrees off-axis and becomes smaller at wider angles. "

Objection, your honor!
The CSD diagram clearly shows that in the 5-6kHz range there is a problem with the decay of the tweeter.
Either the tweeter itself has a problem with decay or/and there is interference with the waveguide.

At 0.21m case width the edge diffraction is normally well below 5-6kHz and does not cause any problems in decay behaviour.

The diagram representation chosen by Amir for the decay behavior of loudspeakers is difficult to interpret, but it can be seen that in the range 5-6kHz the tweeter needs 5-7ms until the signal has decayed to -30dB.
The period length at 5.5kHz is 1/5500 seconds. This corresponds to 28-39 periods until the signal has decayed below -30dB.
Just compare the CSD with the Elac DBR-62.

In Amir's measurements one can clearly see that the 5-6kHz range is still present as a hump in both the LW and ER. Whether this has a clearly negative effect when listening to music I can't judge of course, but this is certainly not optimal.