Revel F208 Tower Speaker Review

[bigguyca]

(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.

- Omitted -

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.

View attachment 115234

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

Determining Power Requirements and Actual Output Using Audyssey

I don't think I did a good enough job of explaining the proposed use of Audyssey to determine power output levels. The idea is that the maximum required and available power levels are known based on the gain structure of Denon/Marantz AVR's and AVP's. Other than running Audyssey, no other measurements are required. OK, one pea, three shells...

The concept of the original post above is that at 0dBFS into the DAC IC the Denon/Marantz gain structure will present 2V SE to the volume control. The varying output levels of a digital source don't enter into any of this. 0dBFS from the digital processing will be the maximum input level to the DAC section, with 2V output, regardless of the digital source. This is fixed circuitry, and is after all digital processing, and all potential gain changes except via the volume control IC.

The volume control IC will provide an output of 2V SE at the RCA outputs for a channel when the external volume control is set at 2.5dB or 82.5dB and the Audyssey offset for that channel is 0dB. These volume control settings represent the same actual output voltage from the RCA outputs. These settings are based on the configuration of the Denon unit by the user. Let's stick with 2.5dB.

This means that at an external indicated volume setting of 2.5dB, the maximum SE output is 2V with 0dBFS into the DAC IC. This output is with the Audyssey offset for the channel set at 0dB.

With a 0dB Audyssey offset for a channel, reference level, which is 0dB indicated on the the external volume control control will result in an SE output of 2V - 2.5dB, and an acoustic output of 105dB SPL at the listening position from each Salon2. The input to an external power amplifier would be 2V - 2.5dB.

For an example with easier numbers, an Audyssey offset of -3.5 dB for a channel would result in an output of 2V - 2.5dB - 3.5dB = 2V - 6dB, that is 1V, at 0dBFS for the channel. If an AHB2 was connected to the SE output, and set for maximum sensativity, the output would be 100W at 2V input. With 1V input the output would be 25W into 8 ohm. This would mean that at reference level of 105dB SPL at the listening position, the output of the AHB2 would be 25W into 8 ohm.

Actually of course the output of the AHB2 would be a voltage. Power output would be determined by whatever current was required to obtain that voltage at any particular instant, since the AHB2 is a voltage source. 25W into 8 ohm, 50W into 4 ohm, xxW into y ohm, etc. Any of these outputs is the result of the same voltage input. If possible, it's best to stick to dB's, voltage and current for these sort of calculations. The AHB2 is an excellent voltage source. Lesser power amplifiers and certainly the mediocre amplifiers in AVR's the voltage would drop off a dB or two into 4 ohms, especially if more channels were driven. This drop-off in voltage limits the maximum SPL output into lower impendences, but we'll ignore that effect.

Another example, an Audyssey offset of +2.5dB for a channel would result in an output of 2V -2.5dB + 2.5dB = 2V. If an AHB2 was connected to the SE output, and set for maximum sensativity, the output would be 100W at 2V input into 8 ohm.

In my case, the Audyssey offset for the Salon2's is 4.5 dB. This means an SE output of 2V -2.5dB +4.5dB = 2V + 2dB would be required for an output of 105dB at the listening position from a Salon2. This means that 105dB can't be achieved since driving an AHB2 with over 2V would result in clipping. The maximum that can be achieved is 105dB - 2dB or 103dB at the listening position. This output would obtained at an indicated setting of -2dB on the external volume control.

Since I rarely listen to material with a reference output (DVD's, Blu-Rays) at over -10dB indicated on the external volume control the AHB2 isn't driven into clipping. At -10dB on the volume control the maximum output from one of the Salon2's of 95dB SPL. There is still headroom to turnup the volume by 8dB.

Material from Amazon Prime or YouTube, or about anywhere else seems referenced to who knows what, but ultimately maximum digital level will be 0dBFS. If listening at the same subjective loudness to these other sources then the maximum output should again be 95dB SPL. There is headroom to 103dB SPL, in case for some reason playback is at higher subjective level. Some material may have a maximum level far below 95dB SPL, other material may be compressed and loud, and continually operate near 95dB SPL.

Thoughts?

 

[Lsc]

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

If you can stretch to the F226Be that would be best.

 

[bigguyca]

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.

(1) 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.

View attachment 115039

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.

(2) 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.
View attachment 115040

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.

(3) Peak SPL Calculator (homestead.com)

View attachment 115045

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

Here are a few thoughts on the post above. The entire post in quoted above, but parts of the post are also extracted below since the post is long and comments can be hard to follow:

Actual Impendence and Combining Speaker Outputs

(1) "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."

Based on measurements in Stereophile the Salon2's have a impedance of about 8 ohm at 1kHz. 1 watt would be more appropriate. Using voltage and dB's would help avoid some of these questions.

Using two speakers (stereo, but actually mono from your description) complicates the measurements. If the same 1kHz signal is played through each Salon2 then, if the measurement is taken equal distant from the two speakers, the gain is 6dB since two coherent single frequency RMS sinewaves are being combined. That means each speaker is producing 80dB SPL at the measurement position. A 3dB gain from two speakers would result from two uncorrelated sinewaves are combined.

If the measurements aren't taken equal distant from the two speakers then a combing effect results and the gain can be anything from almost 6dB to a net zero output as two perfectly out of phase, single frequency signals combine if the speakers are far enough apart. It really would be best to use one speaker for these measurements. Use one speaker and then take separate measurements of the other speaker if added data is required.


Picking on the Crown Power Calculator

(2) "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."

With the Crown calculator there seems to be a RTFM issue. Well OK, the calculator and instructions are on different pages and the calculator doesn't refer to the instructions.

On the Crown website there is a page entitled:

How much Amplifier Power Do I Need?

How Much Amplifier Power | Crown Audio - Professional Power Amplifiers

The page above describes numerous factors for determining the size of amplifier required. The page also defines the factors listed in the Amplifier Required Power tool. Based on the definitions and to make the calculation consistent between the two calculators you have listed, the following should likely be changed:

Sensitivity
In this tool the sensativity is listed at 83dB SPL. In the SPL calculator the sensativity used is 86dB. Using 86dB cuts the power requirement to about 445W.

Peak headroom
Peak Power Headroom should likely be 0. This takes the required power down to about 400W.

Other Considerations
"The calculations discussed here apply to anechoic or outdoor conditions. If the sound system is inside a venue, the room reverberation will increase the SPL typically by 6 dB. You can use this room gain as extra headroom."

Based on the above, the power required from the required power tool can be reduced by 6dB, that is 4X. This takes the required power down to about 100W per speaker. Nominally; for two speakers at a central listening position with correlated sources 25W per speaker would be required. With uncorrelated sources, 50W per speaker would be required.

(3) Peak SPL Calculator (homestead.com)

The calculator has a long sad history.

For many years item 3. stated that there are 3 meters in a foot. One AVS member insisted this was true. This took years to correct.

Until recently the Amplifier Power was listed at Watts RMS. Watts RMS can calculated, but is meaningless. Per memory there was even a video explaining how watts RMS was calculated. It is nice to see that this item has been changed.

The way the "dB Gain from sonic reinforcement" is calculated implies non-collated speaker outputs and a 3dB gain. As noted above, this can easily lead to errors. Besides the error noted above, in the case where a system in used in Stereo Mode, all speakers playing, can easily lead to much higher SPL's in some parts of the room than calculated since the L speakers will al be correlated, as will the R speakers, and the center will have a collation with each. This can easily lead to hearing damage at parties with too much alcohol.

All in all, this calculator has historically been the worst on the Internet IMO. It is also the most referenced.

 

[Rottmannash]

If you can stretch to the F226Be that would be best.

Isn't the F226Be the same speaker as the F206 with a Be tweeter?

 

[Alice of Old Vincennes]

Isn't the F226Be the same speaker as the F206 with a Be tweeter?

Same just cost much more.

 

[Sancus]

Same just cost much more.

The wave guide is improved in the Be versions as well, and in general the directivity seems smoother. You can see this if you compare the Harman data for F206 to F226Be. Erin's data for the F226Be confirms that.

I don't think we have high resolution measurements for the F206, but in any case if you compare Amir's F208 to F328Be measurements there is a significant improvement there as well.

 

[Beave]

Isn't the F226Be the same speaker as the F206 with a Be tweeter?

Different tweeter, yes, but also different woofers, midrange, waveguide, and crossovers.

 

[RichB]

Here are a few thoughts on the post above. The entire post in quoted above, but parts of the post are also extracted below since the post is long and comments can be hard to follow:

Actual Impendence and Combining Speaker Outputs

(1) "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."

Based on measurements in Stereophile the Salon2's have a impedance of about 8 ohm at 1kHz. 1 watt would be more appropriate. Using voltage and dB's would help avoid some of these questions.

While it is certainly true, that 1kHz is almost 8 Ohms, blow 450Hz, it hovers near 4 Ohms. At 250Hz is drops just below 4 Ohms.
There can be every bit the same power requirements at 1kkHz and 100Hz..

Here is Stereophile on the Salon2 impedance:

I estimated the Revel Salon's B-weighted sensitivity as 87dB/2.83V/m, a mite higher than the specification. However, the Salon is basically a 4 ohm loudspeaker, drawing 2W from the amplifier to achieve its sensitivity rating.

This is why I used 4 Ohms at 2.83 volts = 2 watts. I also measured 250Hz with the same SPL.

Using two speakers (stereo, but actually mono from your description) complicates the measurements. If the same 1kHz signal is played through each Salon2 then, if the measurement is taken equal distant from the two speakers, the gain is 6dB since two coherent single frequency RMS sinewaves are being combined. That means each speaker is producing 80dB SPL at the measurement position. A 3dB gain from two speakers would result from two uncorrelated sinewaves are combined.

If the measurements aren't taken equal distant from the two speakers then a combing effect results and the gain can be anything from almost 6dB to a net zero output as two perfectly out of phase, single frequency signals combine if the speakers are far enough apart. It really would be best to use one speaker for these measurements. Use one speaker and then take separate measurements of the other speaker if added data is required.

I suppose we will disagree on the two speaker approach. Without measuring, you posit 0 to 6 dB of gain.
I measured and don't care because there is no use case for 1 speaker.

For the record, the Homestead calculator adds 3 dB for an addition speaker but since I measured 2 and used 2 it is apples to apples.

The speaker measurements are equidistant at the listening position.
I never listen to one speaker and measuring the combined signal removes the guess work of how they combine.
The spreadsheet starts with 86 dB measured from 2 speakers at the listening position and computed it at two watts.
This is the conservative approach, My experience with the AHB2 clip indicators confirms the power estimates are in the ball park.

Picking on the Crown Power Calculator

(2) "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."

With the Crown calculator there seems to be a RTFM issue. Well OK, the calculator and instructions are on different pages and the calculator doesn't refer to the instructions.

On the Crown website there is a page entitled:

How much Amplifier Power Do I Need?

How Much Amplifier Power | Crown Audio - Professional Power Amplifiers

The page above describes numerous factors for determining the size of amplifier required. The page also defines the factors listed in the Amplifier Required Power tool. Based on the definitions and to make the calculation consistent between the two calculators you have listed, the following should likely be changed:

Sensitivity
In this tool the sensativity is listed at 83dB SPL. In the SPL calculator the sensativity used is 86dB. Using 86dB cuts the power requirement to about 445W.

Peak headroom
Peak Power Headroom should likely be 0. This takes the required power down to about 400W.

Other Considerations
"The calculations discussed here apply to anechoic or outdoor conditions. If the sound system is inside a venue, the room reverberation will increase the SPL typically by 6 dB. You can use this room gain as extra headroom."

There is a lot wrong with this calculator I used it as it would be used by a person who found it on google.
It seems intentionally designed to generate huge numbers and would not be that way if there were not Crown amps that supplied the computed power. In any case, to be consistent with my methodology, I plugged in these values 86 dB and it compute 400 watts.
If you believe that two speakers can range from 0 dB gain to 6 dB then the required power is in the range 100 to 400 watts.
This is why a measured two speakers to obtain the baseline.

Based on the above, the power required from the required power tool can be reduced by 6dB, that is 4X. This takes the required power down to about 100W per speaker. Nominally; for two speakers at a central listening position with correlated sources 25W per speaker would be required. With uncorrelated sources, 50W per speaker would be required.

(3) Peak SPL Calculator (homestead.com)

The calculator has a long sad history.

For many years item 3. stated that there are 3 meters in a foot. One AVS member insisted this was true. This took years to correct.

Until recently the Amplifier Power was listed at Watts RMS. Watts RMS can calculated, but is meaningless. Per memory there was even a video explaining how watts RMS was calculated. It is nice to see that this item has been changed.

The way the "dB Gain from sonic reinforcement" is calculated implies non-collated speaker outputs and a 3dB gain. As noted above, this can easily lead to errors. Besides the error noted above, in the case where a system in used in Stereo Mode, all speakers playing, can easily lead to much higher SPL's in some parts of the room than calculated since the L speakers will al be correlated, as will the R speakers, and the center will have a collation with each. This can easily lead to hearing damage at parties with too much alcohol.

All in all, this calculator has historically been the worst on the Internet IMO. It is also the most referenced.

I would say the Crown calculator leads to far greater error.
I measured 250Hz, 1kHz, and 2kHz at 2.83 volts and all measured essentially the same 86 dB.
Measuring below 250Hz runs into room modes so those were excluded, also, our hearing is less sensitive to bass frequencies.
Yes, SPL varies with frequencies in different places around the room. The bass frequencies are very strong when leaning against a wall which can happed when consuming excess alcohol. Once you are on the floor, it does not matter because you are away from the volume control.
Thankfully, the AHB2 can protect users from drunken party volumes by shutting off.

The larger point here (which I know you understand) is that 0 DBFS represents the maximum signal for a digital source.
This can be used to compute/estimate the maximum power and volume setting that will not clip, which you did above through another mechanism.

I don't expect most users will do this using your method or mine so I wanted to provide some perspective and recommend avoiding the Crown calculator and some considerations when using the Homestead calculator.

- Rich

 

[RichB]

The wave guide is improved in the Be versions as well, and in general the directivity seems smoother. You can see this if you compare the Harman data for F206 to F226Be. Erin's data for the F226Be confirms that.

I don't think we have high resolution measurements for the F206, but in any case if you compare Amir's F208 to F328Be measurements there is a significant improvement there as well.

As @Beave stated, the F208 and F228Be share a cabinet, driver size, and driver placement. The drivers and crossovers are different.
The F226Be is much easier to drive, above 6 Ohms at 600 Hz and above. The F208 dips below 4 Ohms at 3kHz and again at 10 kHz.

- Rich

 

[nimar]

As @Beave stated, the F208 and F228Be share a cabinet, driver size, and driver placement. The drivers and crossovers are different.
The F226Be is much easier to drive, above 6 Ohms at 600 Hz and above. The F208 dips below 4 Ohms at 3kHz and again at 10 kHz.

View attachment 115649

View attachment 115650

- Rich

Lesson taken away from this: Spend an extra ~$1K on dual amps / a more powerful amp instead of an extra 10K upgrading from the F208 to the F228Be and call it a day. That is if its even an issue in the first place.

 

[RichB]

Lesson taken away from this: Spend an extra ~$1K on dual amps / a more powerful amp instead of an extra 10K upgrading from the F208 to the F228Be and call it a day. That is if its even an issue in the first place.

Lesson of the day. Most can use one AHB2 to drive these speakers.
Buy the F228Be but don't pay list

- Rich

 

[nimar]

Lesson of the day. Most can use one AHB2 to drive these speakers.
Buy the F228Be but don't pay list

- Rich

I happily settled for not paying list price for a pair of 208s, and a pair of purifi amps for less than one benchmark. The AHB2 wins by far on style but it is unlikely to sound or measure 50% better than even one purifi amp, never mind two.

Fee like there is a good saying in there, “Friends don’t let friends pay list price”

I looked but never found what the actual wholesale cost of 208s was? I know in some industries the markup is regularly 100% and in others it’s multiples of that.

 

[Lsc]

Lesson of the day. Most can use one AHB2 to drive these speakers.
Buy the F228Be but don't pay list

- Rich

Yes that’s a good lesson. Although anyone who bought a F208 probably doesn’t require an upgrade. It all depends on what you are looking for in your system.

I upgraded to the F228Be from my old pride and joy F208 and didn’t pay list .

 

[Kal Rubinson]

I happily settled for not paying list price for a pair of 208s, and a pair of purifi amps for less than one benchmark. The AHB2 wins by far on style but it is unlikely to sound or measure 50% better than even one purifi amp, never mind two.

But will it sound any different and, if so, is it better?

 

[jonfitch]

Lesson taken away from this: Spend an extra ~$1K on dual amps / a more powerful amp instead of an extra 10K upgrading from the F208 to the F228Be and call it a day. That is if its even an issue in the first place.

I doubt you need a more powerful amp even given power requirements are pretty negligible until you get into bass frequencies.

 

[warthor]

What would a reasonable price for F328be "be"? I would love to get that model.

 

[nimar]

I doubt you need a more powerful amp even given power requirements are pretty negligible until you get into bass frequencies.

Perhaps not, but it would quell the desire to upgrade speakers, for a little while at least.

 

[stren]

What would a reasonable price for F328be "be"? I would love to get that model.

Retail is 16k for a pair. Some have claimed 30% off shouldn't be hard to find, so therefore 11K might be a good price. Given that its a newer design, potentially a bigger discount may be harder to find. However you also get to leverage the availability of used salon 2's often being around 10-12K as a datapoint to negotiate lower than that.

 

[Lsc]

Retail is 16k for a pair. Some have claimed 30% off shouldn't be hard to find, so therefore 11K might be a good price. Given that its a newer design, potentially a bigger discount may be harder to find. However you also get to leverage the availability of used salon 2's often being around 10-12K as a datapoint to negotiate lower than that.

Not at my local dealer. He thinks he is doing me a favor by discounting 10%.

 

[Lsc]

Perhaps not, but it would quell the desire to upgrade speakers, for a little while at least.

It’s a slippery slope. But if you wanted to upgrade to the F226Be, your net cash outlay is probably around $2k. So not terrible.