Revel F208 Tower Speaker Review

[RichB]

I'm running 208s in an approximately 4500 cu ft room with 800 wpc into 4 ohm for the front stage (the 208s dip down to ~3.7 ohm per Amir's measurements), but I think that's way more power than I'll ever need. I think 400 wpc into 4 ohm will be more than enough unless you plan to open the windows and play a concert for your neighbors. The only thing I would make sure is that amp is rated at full bandwidth, not something like 1khz. If it puts out 400 wpc into 4 ohm continuous with full bandwidth and low THD, then I think you're good to go!

On the question of 208s vs. 206s, I auditioned the 206 at the dealer and ended up with the 208. The 208 renders a larger soundstage with more perceived depth because of its mid/low output. Everyone here told me go 208s and I'm glad I did. They are the best speakers I have owned.

I had the same question when I bought the AHB2 and drove the Salon2s with a single AHB2 in stereo mode.
Aquaman BD played loud (to our tastes) was putting out some serious bass and the AHB2 was not clipping.

This was puzzling so I decided to measure my Salon2s at my listening position to get a power baseline.,
A stereo sine-wave at 0 DBFS 1Khz (also 2kHz and 205 Hz) and 2.83 volts produced 86 dB at my listening position.
The Salon2s are basically 4 Ohms so that computes to 2 watts. With that as a base, I plugged that into a spreaksheet to compute the maximum power usage at volume levels labeled to match my habits.

With digital signals, these are the maximum power at each Volume setting.

This may be too complex for most but it is an accurate measurement of my power requirements.

The problem with power calculators is it is easy to be off by 4X.
Here is the crown calculator for power required for 101 dB.

This is one speaker so, for two cut it in half and that is 445 watts versus the measured power of 64 watts. The crown calculator over estimates by over 7 times.

Here is a better SPL calculator for 2 speakers with the most optimistic settings for gain, 86 dB (though at 4 Ohms it uses 2 watts), my speakers are not really in the corner but it gives more gain.

Peak SPL Calculator (homestead.com)

With optimistic settings, this calculator computes that 101 watts produces 104.5 dB at the listening position.
This calculator shows that100 watts produces 104.5 compared to my measurements where 100 watts produces about 102.5 dB (eyeballing it).

Basically, a normal seating position with 2 speakers reasonably close to the rear wall are going to deliver about the same as their sensitivity ratings at 10 feet in most rooms. This calculator (Peak SPL Calculator (homestead.com) ) is pretty good with "In Corner", in my case, even though the Salon2s are not stuffed into the corner but are within 2 feet of the rear wall.

- Rich

 

[bigguyca]

Random question about the 208's - and apologies if this is a dumb question as I'm very new here. I'm looking at pairing the 208's with the Musical Fidelity m6si which I think is 220 wpc at 8 ohms. Would this amplifier have enough juice to power these speakers? I'm torn between getting these where I'd be in the middle of their recommended watt per channel recommendation ... or the 206's where I'd be on the high-end. I'm just concerned the 206's won't have enough "oomph" for that room.

I don't think they publish 4 ohm wpc for the Musical Fidelity m6si but on Crutchfield they say it's 400 wpc at 4 ohm. I'd be listening in a largish room (19 x 17) with a high ceiling but never listen at a very high volume - mainly jazz/classic rock/soul r&b/classical. I wouldn't be pairing these with any sub so they'd need to be adequate by themselves bass-wise.

Any help would be MUCH APPRECIATED as I don't know how to interpret these graphs and buy new stereo equipment about once every 10-15 years!

-Geoff

The F208 is the speaker you want.

Will your M6si drive the F208's to suit your tastes? Likely, if you only listen at modest levels.


While no one else who commented on your question saw this as a problem, it does appear that you are referencing data from on the MF M6i from the Crutchfield website. While the M6i and M6si have close model numbers, and have similar rated output at 8 ohms, that doesn't mean the 4 ohm rating from the M6i can be applied to the M6si. The two products are different.


The following may be more than you want to know:

Do keep in mind that having better equipment often leads to listening at higher SPL levels.

Stereophile found the sensitivity of the F208 to 88.9 dB SPL. This sensativity is quite high, which is good. Of course the measurement is into 8 ohm. The impedance drops below 4 ohm at times. Combinations of phase and impedance, which stress the amplifier, may cause issues and may trigger protection circuits.

Revel Performa3 F208 loudspeaker Measurements | Stereophile.com

A typical AVR has one pair of power transistors per channel and will handle over 100W. The M6si has two pairs of power transistors and they are likely heavier duty transistors than found in a AVR. This means that the M6si can support reasonable loads.

If you do have problems driving the F208 it will likely be during extended listening at high levels, which you evidently don't do. The M6si appears to have a suboptimum design for eliminating heat from the output stage. This may be why it is not rated for 4 ohm loads. If a 4 ohm load is driven at a high level for an extended period of time then the M6si may overheat.

Here is a picture of the inside of an M6si from the Internet. Note that the four power output transistors on each side are mounted together at one end of the heat sink. The heat will not transfer well along that heat sink, but will be concentrated at one end. The heat sink has horizontal fins on the exterior. This is not a good design for passive cooling; hot air rises.

 

[alashikata]

Parasound A21 would be better for Salon2 since it has huge bass compare to F208. F208 has better bass than Studio 2. AHB2 may not enough for Salon 2 even though it's a decent apm.

 

[Coach_Kaarlo]

2 x AHB2’s in bridged mono with my F208’s sounds very good, which equates to over 600W per channel @ sub 4 ohm impedances.

The min impedance is 3.4 ohms.

They will play to 30 Hz in reasonably large rooms!

They are a great speaker for the price, and with some DSP and room corrrection, will be good enough to enjoy for years to come. But look carefully at amplification and the DAC (and or DSP / room correction), as money invested there will help the F208’s deliver their full potential.

 

[RichB]

Parasound A21 would be better for Salon2 since it has huge bass compare to F208. F208 has better bass than Studio 2. AHB2 may not enough for Salon 2 even though it's a decent apm.

I currently bi-amp the Salon2s with an AHB2 each, there there is the option to bridge.
At one time, I had a pair of A21 bi-amping the Salon2s. The A21 should provide a 3 dB more output.

The AHB2 has the best speaker protection out there and the cleanest output.
I consider this amp an upgrade over the A21.

At some point, I plan to bring an AHB2 over to my brother in-laws to compare it to his A21 driving the F206s.

- Rich

 

[alashikata]

F206 is not that great to test with. Probably won't give a good sound with AHB2. Your brother in-laws got overkill amp for F206. If you have money for JC5, that would be the best upgrade over AHB2. Do you have BenchMark DAC2? A great combination with AHB2

 

[RichB]

F206 is not that great to test with. Probably won't give a good sound with AHB2. Your brother in-laws got overkill amp for F206. If you have money for JC5, that would be the best upgrade over AHB2. Do you have BenchMark DAC2? A great combination with AHB2

I bi-amp the Salon2s with the AHB2 with no issues and no clipping at my desired levels.
Others with different habits may want more power. But since I am listening the 1 watt or less most of the time, the AHB2 is wonderful.
What accounts for that, I cannot say, but it would be hard to switch to an amplifier with 100x more THD+N for most listening.

JC-1 Distortion into 4 Ohms (could not find the JC-5 distortion but the JC-1 is probably better):

AHB2 Bridged Distortion into 4Ohms

At 1 watt, JC-1 is 0.03 THD+N and the AHB2 is 0.0002.

JC-5 Specs:
Price: 5,995 ($6K)
Power: 600 WPC into 4 Ohms
Weight: 90 lbs
Idle power: >100 Watts (it was about 100 on my A21)

AHB2 Specs:
Price: $2,995 ($6K for 2 dual mono)
Power: 500 WPC into 4 Ohms (bridged)
Weight: 12 lbs. (24 for 2)
Idle power: 12 Watts (24 for 2)

Can you guess which of these I recommend?

- Rich

 

[alashikata]

I have never listened to JC1 yet but did have JC5 + JC2 BP. I think most Revel speakers require at least 50wpc amp so AHB2 should be perfect if you don't listen too loud and the case design is small too.

 

[Rottmannash]

I've had the F206 for a year now and those speakers sound really good in the sweet spot and even throughout the house.
View attachment 62564

My system- Node 2i>D70>Freya+>VTV Purifi Eval 1>F208's.

Are we twins?

 

[Rottmannash]

The F208 are $5,000 MSRP speakers, which means that are actually $3500ish speakers from a good dealer. And I'm willing to bet they extend well below 30 Hz easily in room(not that it really matters since they should be crossed to subs, of course).

Revel F36 in room:
View attachment 62565

I can tell you that guesstimate on price is spot-on.

 

[Rottmannash]

You have to develop the techniques.
I've had to handle my F206s and my Studio2s (many of them) and many others over the years. I do have my limits but I've handled speakers up to 150lbs. as long as they have friendly shapes (tall, slim) and well-placed ports.

Indeed, the toughest part of unpacking/installing the F206 was the removal of the sticky plastic film.

Oh my yes ! I was exhausted trying to pull that damned plastic wrap off my F208's.

 

[bigguyca]

I currently bi-amp the Salon2s with an AHB2 each, there there is the option to bridge.
At one time, I had a pair of A21 bi-amping the Salon2s. The A21 should provide a 3 dB more output.

The AHB2 has the best speaker protection out there and the cleanest output.
(2) I consider this amp an upgrade over the A21.

At some point, I plan to bring an AHB2 over to my brother in-laws to compare it to his A21 driving the F206s.

- Rich

(1) I bi-amp the Salon2s with the AHB2 with no issues and no clipping at my desired levels.
Others with different habits may want more power. But since I am listening the 1 watt or less most of the time, the AHB2 is wonderful.
What accounts for that, I cannot say, but it would be hard to switch to an amplifier with 100x more THD+N for most listening.

- Graphs omitted -

(2) At 1 watt, JC-1 is 0.03 THD+N and the AHB2 is 0.0002.

JC-5 Specs:
Price: 5,995 ($6K)
Power: 600 WPC into 4 Ohms
Weight: 90 lbs
Idle power: >100 Watts (it was about 100 on my A21)

AHB2 Specs:
Price: $2,995 ($6K for 2 dual mono)
Power: 500 WPC into 4 Ohms (bridged)
Weight: 12 lbs. (24 for 2)
Idle power: 12 Watts (24 for 2)

Can you guess which of these I recommend?

- Rich

(1) Using Audyssey results for the measurement, one Salon2 bi-amped with a AHB2 in stereo mode, produces 103dB SPL at my listening position with 2V input to the AHB2. The listening position is 10 ft. from the speaker in a treated room. The AHB2 is set for maximum sensativity. This means that the output is equivalent to 100W into 8 ohm or 200W into 4 ohm with a 2V input. Bi-amping has no effect on these calculations.

Typically I use various D/M gear for home theater so this means that as long as I watch a movie at a 78/-2 volume control setting I'm not clipping the AHB2 even if the Salon is used full range. Like most people I listen at -10 or less vs. reference level, so I'm not close to clipping the AHB2.

(2) Parasound uses JFET's in the input stage of their power amplifiers. JFET's have 20dB or so less transconductance than bi-polar transistors. This is likely the reason why Parasound power amplifiers have 20dB more distortion that a similar amplifier with bi-polar transistors, such as a Bryston 4b3 or 4BSST2. The AHB2 is in another league and reduces distortion by another 10dB or more.

Certainly one AHB2 would be excellent driving a pair of F208's. Bi-amping with AHB2's is overkill, but you only live once...

 

[nimar]

With bi-amping the 208s, are the top terminals serving the mid+tweeter, then the bottom the two bass drivers. Am actively considering bi-amping with two stereo amps, 4x400W@4ohm. Based on the impedance graph above looks like above the 500hz transition it’s more like a 6-4ohm speaker, so the separate amp might go to good use.

 

[steve59]

Go for it.

 

[Rottmannash]

(1) Using Audyssey results for the measurement, one Salon2 bi-amped with a AHB2 in stereo mode, produces 103dB SPL at my listening position with 2V input to the AHB2. The listening position is 10 ft. from the speaker in a treated room. The AHB2 is set for maximum sensativity. This means that the output is equivalent to 100W into 8 ohm or 200W into 4 ohm with a 2V input. Bi-amping has no effect on these calculations.

Typically I use various D/M gear for home theater so this means that as long as I watch a movie at a 78/-2 volume control setting I'm not clipping the AHB2 even if the Salon is used full range. Like most people I listen at -10 or less vs. reference level, so I'm not close to clipping the AHB2.

(2) Parasound uses JFET's in the input stage of their power amplifiers. JFET's have 20dB or so less transconductance than bi-polar transistors. This is likely the reason why Parasound power amplifiers have 20dB more distortion that a similar amplifier with bi-polar transistors, such as a Bryston 4b3 or 4BSST2. The AHB2 is in another league and reduces distortion by another 10dB or more.

Certainly one AHB2 would be excellent driving a pair of F208's. Bi-amping with AHB2's is overkill, but you only live once...

Why did I think JFET stages were soniçally superior? Aren't they used in some high end HP amps? Or is all this a fever dream?

 

[RichB]

With bi-amping the 208s, are the top terminals serving the mid+tweeter, then the bottom the two bass drivers. Am actively considering bi-amping with two stereo amps, 4x400W@4ohm. Based on the impedance graph above looks like above the 500hz transition it’s more like a 6-4ohm speaker, so the separate amp might go to good use.

I made my decision to bi-amp after listening after some single blind tests (SBT).
JRiver was used to play short selections from a number of tracks with uncluttered instruments and female vocals at about 80 dB. This avoids overloading my ears and fatique.

A single speaker is used and two channels of the the amplifier where the source is split using a Y connector.
I did not want to rely on the a AVP/AVR bi-amp function because the signal path is unknown. Some may use DSP functions that degrade performance even in Pure Direct mode. Of course, make sure that no processing enabled.

The obvious precautions apply, but for completeness, disconnect the straps and make sure the unused channel leads never connect. I expect most amps tolerate it but why take the chance.

Create a short 10 to 12" patch cable with banana connects.
A friend can switch between 2 amps and a single amp by swapping the extra channel and patch cable while out of sight of the listener.

Trust me, you get lambasted on forums for passive bi-amping, but I find an increase in clarity. At 80 dB, this is below 1 watt.

Some theories on what could affect the performance bi-amped:

1. Interaction between the crossovers - This is not inconceivable given that Revel placed each crossover on its own board to avoid electromagnetic interference. Bi-amping removed electronic interference.
2. Reduced amplifier distortion - Amplifier tests show some amps have intermodulation distortion. There are measurements showing interaction between 50Hz and 7 kHz (or similar).
3. Increased power - This is not the best way to increase power, but clearly at high volume, the bass section can clip without affecting the upper amp.

Interaction between crossovers would largely unaffected by the amplifier design and I have found this to be true. I have bi-amped the Salon2s with Parasound A21, ATI AT6000, and now Benchmark AHB2s.

While there could be some increase in power, it will be limited. Voltage amplification is not improved but current amplification can be. When current limited, one amp can clip before the other. With the Salon2s and selection music sections, I observed the upper AHB2 provided about 1 dB more output before illuminating the clip indicators, so about 60 to 120 watts

I suppose this effect could be measured but I am not sure how.
There are a lot of tweaks things out there but here is one that anyone can SBT at very low cost.
Then, you can make your own decision (that may not be for everyone).

I have a friend with good hearing that is not an audiophile and does not own a stereo or HT system.
I kept calling him into the to listen do another test. He identified bi-amp'ed every time.
The last 5 tests I called him into the room, he correctly identified bi-amped before switching. Then I gave up.
Honestly, he was better at it than I.

- Rich

 

[nimar]

I made my decision to bi-amp after listening after some single blind tests (SBT).
JRiver was used to play short selections from a number of tracks with uncluttered instruments and female vocals at about 80 dB. This avoids overloading my ears and fatique.

A single speaker is used and two channels of the the amplifier where the source is split using a Y connector.
I did not want to rely on the a AVP/AVR bi-amp function because the signal path is unknown. Some may use DSP functions that degrade performance even in Pure Direct mode. Of course, make sure that no processing enabled.

The obvious precautions apply, but for completeness, disconnect the straps and make sure the unused channel leads never connect. I expect most amps tolerate it but why take the chance.

Create a short 10 to 12" patch cable with banana connects.
A friend can switch between 2 amps and a single amp by swapping the extra channel and patch cable while out of sight of the listener.

Trust me, you get lambasted on forums for passive bi-amping, but I find an increase in clarity. At 80 dB, this is below 1 watt.

Some theories on what could affect the performance bi-amped:

1. Interaction between the crossovers - This is not inconceivable given that Revel placed each crossover on its own board to avoid electromagnetic interference. Bi-amping removed electronic interference.
2. Reduced amplifier distortion - Amplifier tests show some amps have intermodulation distortion. There are measurements showing interaction between 50Hz and 7 kHz (or similar).
3. Increased power - This is not the best way to increase power, but clearly at high volume, the bass section can clip without affecting the upper amp.

Interaction between crossovers would largely unaffected by the amplifier design and I have found this to be true. I have bi-amped the Salon2s with Parasound A21, ATI AT6000, and now Benchmark AHB2s.

While there could be some increase in power, it will be limited. Voltage amplification is not improved but current amplification can be. When current limited, one amp can clip before the other. With the Salon2s and selection music sections, I observed the upper AHB2 provided about 1 dB more output before illuminating the clip indicators, so about 60 to 120 watts

I suppose this effect could be measured but I am not sure how.
There are a lot of tweaks things out there but here is one that anyone can SBT at very low cost.
Then, you can make your own decision (that may not be for everyone).

I have a friend with good hearing that is not an audiophile and does not own a stereo or HT system.
I kept calling him into the to listen do another test. He identified bi-amp'ed every time.
The last 5 tests I called him into the room, he correctly identified bi-amped before switching. Then I gave up.
Honestly, he was better at it than I.

- Rich

Doesn’t seem to be any voodo in bi-amping speakers that have separate inputs for it. Bi-wiring on the other hand is entirely magical thinking.

As to point 3. It might actually be a better way to get more power, (watts per driver ) than just using a beefer amp as there will have to be a trade offs in distortion etc in just putting more power in a single amp. Especially as discussed above the different drivers pull varrying current at different frequencies.

It’s a poor logical argument, but there is likely a reason that active monitors are generally bi-amped.

 

[RichB]

(1) Using Audyssey results for the measurement, one Salon2 bi-amped with a AHB2 in stereo mode, produces 103dB SPL at my listening position with 2V input to the AHB2. The listening position is 10 ft. from the speaker in a treated room. The AHB2 is set for maximum sensativity. This means that the output is equivalent to 100W into 8 ohm or 200W into 4 ohm with a 2V input. Bi-amping has no effect on these calculations.

Very interesting and are a close match to my the computation based on measuring 2.83 volts at my 11 foot listening position.
At XMC-1 volume -13 I computed 104 dB requires 128 watts that will not clip driving the Salon2s that are closer to 4 Ohms than 8 through most frequencies.

Playing music at -10 (Salon2s), I could consistently clip using music tracks but not at -13.

Movies are tough to gauge, especially with the RMC-1.
The volume level varies with the source component and the source format. For example, with TiVo and Dolby Digital, I never go below -28. On the ATV4K, Atmos, and BDs, I may go as low as -12. I attribute this to overzealous attenuation decisions made by the processor that are tuned for 16 channels. It seems that this processor sometimes applying up to 18 dB attenuation to allow for 14 channels of bass management.

This is an issue for all digital processors with high-channel counts. Some may not provide as much attenuation and rely on probability to avoid digital clipping or could apply bass attenuation/compression. There are no standardized rules for digital bass management with digital clipping.

I have observed that -12 (loud) on some concert movies, the AHB2s are not clipping.
For example, my family watched a "A Star is Born" (Gaga version) and "Yesterday" (great movie) on my 5.1 system as loud as my family would tolerate and there were no signs of strain or clipping.

Measurements and use have shown the AHB2 need not be bridged to achieve my estimation of loud listening levels.
There was a time, that I would turn up the system to concert loud for fun. I did that with the Sunfire Signature (400 WPC) amps and the Salon1s and cooked a midrange. I have no desire to repeat this experience. My hearing is important to me now that I am well past my 40'th birthday.

I love the AHB2 performance and have also come to love, excellent clip indicators and well implemented clipping protection that assures my speakers are not damaged.

- Rich

 

[RichB]

Doesn’t seem to be any voodo in bi-amping speakers that have separate inputs for it. Bi-wiring on the other hand is entirely magical thinking.

As to point 3. It might actually be a better way to get more power, (watts per driver ) than just using a beefer amp as there will have to be a trade offs in distortion etc in just putting more power in a single amp. Especially as discussed above the different drivers pull varrying current at different frequencies.

It’s a poor logical argument, but there is likely a reason that active monitors are generally bi-amped.

Active speakers have separate amps for efficiency and to implement active crossovers with DSP. There is no question that this can provide improved efficiency and performance.

Passive crossovers speakers can have excellent performance but I think the high-end market has stayed away for a number of reasons (IMO). It is not convenient to run power to each speaker. Amps can fail and the servicing of an built-in amps can be an issue. An outboard box with amps and crossovers is the best logistically but if standard connections are used, a customer could blow up their tweeter by making the wrong connection.

High-end dealer want to sell you those 200 lbs. kilowatt amps, firehose cable, and amplifier stands.
There are logistical and market reasons that high-end active speakers are not more prevalent.

- Rich

 

[Alice of Old Vincennes]

Random question about the 208's - and apologies if this is a dumb question as I'm very new here. I'm looking at pairing the 208's with the Musical Fidelity m6si which I think is 220 wpc at 8 ohms. Would this amplifier have enough juice to power these speakers? I'm torn between getting these where I'd be in the middle of their recommended watt per channel recommendation ... or the 206's where I'd be on the high-end. I'm just concerned the 206's won't have enough "oomph" for that room.

I don't think they publish 4 ohm wpc for the Musical Fidelity m6si but on Crutchfield they say it's 400 wpc at 4 ohm. I'd be listening in a largish room (19 x 17) with a high ceiling but never listen at a very high volume - mainly jazz/classic rock/soul r&b/classical. I wouldn't be pairing these with any sub so they'd need to be adequate by themselves bass-wise.

Any help would be MUCH APPRECIATED as I don't know how to interpret these graphs and buy new stereo equipment about once every 10-15 years!

-Geoff

The manufacturer doesn't seem to publish spec for 4 ohm. The Crutchfield spec is for the predecessor model. Any amp that doubles from 8 to 4 ohm is a high current amp. I can't find any specs or measurements to confirm. I would be wary of amp that does not provide 4 ohm rating.