Revel F208 Tower Speaker Review

[GelbeMusik]

I’m skeptical of Harman’s in-house measurements as well.

The very low bass is going to be altered by room interaction anyways. If You look at the impedance graph, the bass reflex tuning is extremely low, at about 25Hz.
- it allows for plenty of equalization, especially boosting the lowest rumbles to ones liking
- it allows for effective room gain down to very low frequencies
- it weakens the musical range, starting at 40Hz effectively
- with higher distortion there
- with lower level there

For sure it is a compromise, so, on one hand it can be found to be a feature. You can't have both at the same time at this cost and size. With a 5k price tag an equalization in the lowest range should be obligatory. If not available, I would rather prefer that shallow bass response over full, and then in-room exaggerated bass.

 

[Vuki]

This measurement may throw some light on what kind of LF response you can expect in room from F208. I measured this after quick EQ in dealer's demo room (app 25m2), speaker was app 1m from side and rear wall. Subjectively this speaker played LF with authority and firmness.

Nice. What's up with the response above 4kHz?

 

[QMuse]

Nice. What's up with the response above 4kHz?

Unprecise MMM measurement.

It was at dealer's demo room and I was concentrating on measuring the LF so I can do room EQ.

Here is the on-axis sweep I took from app 1m distance:

Btw, I was impressed with this speaker's performance, it simply did everything right.

 

[Koeitje]

I thought the Salon 2 went down to 20hz? or maybe that was the M2 I was thinking of?

From the top of my head M2 is flat till 40hz then drops pretty hard to 20hz but still with usable output I think. They also sell a complementary 18" sub for the M2, so even with the M2 subs are good.

 

[ctrl]

The manufacturer's specifications for the low bass cut-off frequencies seem to be wrong, as Amir already said.

F208 Low bass measurements
Manufacturer: -6dB@27 Hz, -3dB@31Hz
Stereoplay Magazine 2/2014: -6dB@34 Hz, -3dB@44Hz
ASR - NFS: -6dB@42 Hz, -3dB@52Hz

Strangely enough, Amir's measurements of the F208 show a very high low bass cut-off frequency.

@amirm , could it be that the "Boundary" switch was active during the measurement? When the switch is activated, the Stereoplay review also shows an f3 of over 50Hz.

Stereoplay Magazin 02-2014

 

[MZKM]

I get the feeling (ha!) that Revel/Harman are targeting a straight, downward sloped in-room response curve even at the cost of uneven on axis FR response. Would that be based on their (unpublished) blind preference tests? Seems plausible.

For example, KEF LS50 is generally very well regarded, but shows not so great on-axis frequency response. Yet, its simulated in-room response is pretty good.

Well, the in-room is used for the scoring.

 

[pierre]

 

[vavan]

This measurement may throw some light on what kind of LF response you can expect in room from F208.

Remember my measurements where it clearly goes down around 31 Hz

 

[pierre]

Harmann v.s ASR from https://pierreaubert.github.io/spinorama/compare.html

Revel F208 ASR v.s. Genelec 8341A ASR: except the bass, they are very similar. I agree it is strange that the floorstander cannot go lower.

 

[Ilkless]

This measurement may throw some light on what kind of LF response you can expect in room from F208. I measured this after quick EQ in dealer's demo room (app 25m2), speaker was app 1m from side and rear wall. Subjectively this speaker played LF with authority and firmness.

View attachment 62620

-6dB at 30Hz suggests the more conservative extension is correct

 

[Robbo99999]

Can the klippel bass measurements be trusted? Seems a lot of floorstanders are measuring poorly sub 100hz

Yes, I've been noticing the same trend, makes me think the klippel doesn't really capture the bass response of floorstanders properly, especially given that these are 8" woofers on this tower, so they should play low I think.

This measurement may throw some light on what kind of LF response you can expect in room from F208. I measured this after quick EQ in dealer's demo room (app 25m2), speaker was app 1m from side and rear wall. Subjectively this speaker played LF with authority and firmness.

View attachment 62620

Interestingly that bass is rolling off at the same place as my 8" woofers in my JBL308p Mkii's that have a 2dB low shelf boost - I guess that makes sense as they're both 8" woofers yet mine has to specialise in playing a bit further up the frequency range as it's a 2 way speaker. Shouldn't the klippel measurements of this F208 tower speaker show further extension into the low bass given your in room measurements there? If not then praps you can't use Klippel measurements as a judge to how far speakers will extend into the low bass when actually listening to them?

 

[QMuse]

-6dB at 30Hz suggests the more conservative extension is correct

I agree. Still, plenty of clean bass was coming from F208 when I auditioned them. My guess is it would suffice wihtout the sub for most music listening purposes.

 

[QMuse]

Interestingly that bass is rolling off at the same place as my 8" woofers in my JBL308p Mkii's that have a 2dB low shelf boost - I guess that makes sense as they're both 8" woofers yet mine has to specialise in playing a bit further up the frequency range as it's a 2 way speaker. Shouldn't the klippel measurements of this F208 tower speaker show further extension into the low bass given your in room measurements there? If not then praps you can't use Klippel measurements as a judge to how far speakers will extend into the low bass when actually listening to them?

I think it's quite hard to estimate LF in-room response considering the differences in gain that are position dependent. If you put F208 in the corner would get higher LF response. Anyway, the point with them is they can handle 30Hz upwards and if it isn't enough you need to get the sub. IME the same is the case with most of large floorstanders.

 

[carlob]

I posted the F228Be spinorama few posts back, it's a Klippel measurement by Harman. Here it is again.
I think the 228Be should not be so different in bass extension so maybe it would be interesting to overlay it to the F208 ASR spin.

 

[vavan]

My guess is it would suffice wihtout the sub for most music listening purposes

It really is

 

[tuga]

I think it's quite hard to estimate LF in-room response considering the differences in gain that are position dependent.

And also room-construction dependent.

 

[skyfly]

Are acoustic 4th order slopes necessary for smooth off-axis response curve?

JBL 4319 had some acoustic 2nd order and 1st order slopes, and the off-axis curves were poorer than those of a Revel.

 

[ctrl]

What went wrong with the CSD measurement?

If the measurement is correct, there would be massive oscillation around 8000Hz.
It would take 18 oscillation periods@8kHz alone until the signal drops relevant in the sound pressure - this would be devastatingly bad decay behavior.

Does the F208 behave noticeably when playing back sibilants?
Does the blood shoot from the ears when Katie Melua sings "Nine Million Bicycles"?

Does anyone know of any other sources for the decay behavior of the F208?

 

[Absolute]

It makes sense to tune normal home speakers to around 40 hz in order to not kill the sensitivity, so that's not a surprise to see from most manufacturers.

Most of us know that deep bass is all about the room and that quality bass can only be achieved through separated subs and/or EQ (unless you go ballistic with absorbers).
That should make the accuracy of the spins in the deep end a rather pointless datapoint in the eyes of most here, but it's obviously not and I'm a little surprised by that.

I'm aware of the preference rating criteria, but I'm also quite certain that most people here would not make a case that a speaker playing down to 20 hz by itself would sound better than the same speaker playing down to 60 hz and then crossed over to subs to reach 20 hz.

In my mind it's interesting to see where the speaker rolls off by design, but it's not important that the measurement is on point or off by a couple of dB as it wouldn't matter in a room anyway.

You know, my 2 cents, imo etc.

 

[ctrl]

Are acoustic 4th order slopes necessary for smooth off-axis response curve?

No, the filter order is not decisive for a uniform radiation.

But the lower the filter order, the wider the frequency range in which the filter slopes and phase alignment must be correct, which is usually very difficult to achieve. In addition, there is the influence of the baffle and the radiation of the individual drivers.

JBL 4319 had some acoustic 2nd order and 1st order slopes, and the off-axis curves were poorer than those of a Revel.

A crossover with different acoustic filter slopes is almost never a good idea. This almost always leads to an uneven vertical radiation with side lobes.
As is the case with the JBL 4319 - see the black circles in the diagram.