MartinLogan Renaissance 15A vs. Revel PerformaBe F328Be

[Sonnie Parker]

This is somewhat of an unofficial preliminary listening evaluation with these two sets of speakers. These will be part of our official evaluation event first of July, although we don't normal pit speakers against one another in our evaluations. In this case, I am seriously considering the Revels for my personal speakers, so I have no choice but to compare them.

I've had the 15A's in my room for a few months now and have been very pleased with them. I've owned the Montis and 13A's in the past and both were phenomenal speakers that I seriously missed having in my room after they left me. I've had other stats, but none like those, so I decided I would to all out and grab the 15A's. Thus far... no doubt the best sounding speakers I've had in my room.

The reason I selected the Revels for consideration was because I've heard so much about their speakers being extremely neutral. I started looking around, reading reviews and they ended up really getting my attention. Even though several reviews also expressed how the 15A's are also neutral, they are electrostats, and the Revels are dynamic, so they should be different, at least I would think. I started out wanting to order a pair of F208's, but could not find any, then decided to order the F228Be. After investigating, it was clearer to me that the F228Be model was an upgrade to the F208. After ordering and paying for them, Harman emailed me back that they were seriously back-ordered on the 228's but could ship me a pair of the 328's right away... why not, no reason to argue... and they are here. They've been sitting in my shop for a few weeks and I decided to unpack them and give them a listen this weekend.

To Revel's credit... I have never seen a speaker packed so well. Similar to the 15A's they are covered with a soft cloth material and have foam that slips down over and completely surrounds the speakers, with protection on top and bottom, and then placed inside their respective boxes. The key difference in the Revels is they are then placed inside of what appears to be a pro audio rack case, which are easy to roll around.

After unpacking the 328's, I placed them next to the 15A's... considerably smaller in comparison. I'm not sure why Revel used white coned drivers... as I'll have no choice but to use the grills if do decide to keep them, despite not being fond of grills on my speakers. The white coned drivers are not a pretty sight for me.

This is NOT how I will listen to them. I'll move the 15A's out of the way and and find the right position for the 328's... this is merely capturing the size comparison.

More to come!

 

[Sonnie Parker]

Impedance plots of each speaker.

15A Notes
4 ohms @ 2.5kHz
3 ohms @ 3.5kHz
2 ohms @ 7.1kHz
1.5 ohms @ 10kHz
1 ohm @ 14kHz
.6 ohm @ 19.5kHz

Revel Notes
4 ohms @ 75Hz
3.3 ohms @ 100Hz
3 ohms @ 215Hz
4 ohms @ 400Hz

Impedance Overlay

 

[Sonnie Parker]

I started by first listening to the 15A's again... without any filters, but crossed over at 50Hz to the subs. The filters that Mitch (Accurate Sound) are what I would say very reserved, not drastic, and the 15A's still sound quite phenomenal without the filters. I wanted to listen without filters because I have nothing prepared for the 328's. I will eventually setup Dirac on both and compare, and may get Mitch to fix me up a similar targeted response as the 15A's for the 328's. For now... both are raw from 50Hz on up.

Not surprising that the best location for the 328's is very close to where I had the 15A's.

 

[Sonnie Parker]

The warning lights on the Benchmark AHB2 bridged amps start flashing with the 15A's at moderate levels. I have not measured the level on the 15A's, but it does seem to be about the same as the F328's, which I am unable to get as loud as I would like on some songs, same as the 15A. Measuring the 328's with my UMIK-2 and REW's SPL meter, the lights start flashing at about 88-89dB, which is max volume I can reach, unless I turn up the gain within the SHD, which I have not done with any amp or speaker to date. I thought perhaps the 15A's were causing the lights to flash because of the dip down below 2 ohms starting at about 7kHz, where there would be plenty of info, and that could be causing it. The 328's drop to 3 ohms from about 100Hz up to 215Hz... and perhaps that is just as strenuous on the amps as the what the 15A's are doing. Or both are such that they are causing the amps to run out of power.

This is 27 seconds into Yello's Till Tomorrow from their Touch CD... warning lights flashing in the same manner as the 15A's.

 

[Sonnie Parker]

So how do they sound in comparison to the 15A's... hmmm... they sound different. For better or worse... well... I can't say because that might influence Wayne and Dennis one way or the other for our evaluation, so I'll have to wait and announce my verdict after the evaluation. Plus I need more time with the 328's too... this is only one night, and I'd like to hear them both back and forth several times, with and without convolution and Dirac Live.

TO BE CONTINUED AT THE EVALUATION!

 

[RichB]

The warning lights on the Benchmark AHB2 bridged amps start flashing with the 15A's at moderate levels. I have not measured the level on the 15A's, but it does seem to be about the same as the F328's, which I am unable to get as loud as I would like on some songs, same as the 15A. Measuring the 328's with my UMIK-2 and REW's SPL meter, the lights start flashing at about 88-89dB, which is max volume I can reach, unless I turn up the gain within the SHD, which I have not done with any amp or speaker to date. I thought perhaps the 15A's were causing the lights to flash because of the dip down below 2 ohms starting at about 7kHz, where there would be plenty of info, and that could be causing it. The 328's drop to 3 ohms from about 100Hz up to 215Hz... and perhaps that is just as strenuous on the amps as the what the 15A's are doing. Or both are such that they are causing the amps to run out of power.

This is 27 seconds into Yello's Till Tomorrow from their Touch CD... warning lights flashing in the same manner as the 15A's.

View attachment 41660

Do you possess a voltmeter?
You could play a 0 dBFS sine-wave and measure 2.83 volts at the speaker terminals. This gives a baseline of 1 or 2 watts (depending on load). From there you are working with a DB scale so whatever the volume is on the SHD -26 (or so) from there is all there could be.

I have measure (with two Salon2) 2.83 volts with 250hz, 440Hz, 1kHz, and 2kHz 0 dBFS (maximum) sine-waves and the match at 86 dB at 11 feet. Though the Salons rated efficiency is 86dB, but the room gain account for the addition. It may well be that my room has more gain.
These AHB2s are drive by a Benchmark LA4 that can easily drive the AHB2s in low gain mode.
Perhaps, that is factoring in somehow.
Here are my computed volume levels which I have verified achievable and the clip indicators illuminate when the max power is exceeded.

The tests and computed values were obtained using the AHB2 in stereo mode bi-amping the Salon2s. Bridged, they should be able to achieve 110 dB (in stereo). These are RMS computation not peak.

The SHD cannot properly drive the AHB2s in low gain mode, since it tops out a 4 Volts.
Try setting the AHB2s to high-gain mode just to see if things change.
Something is not right here. Is there another preamp you can try?

- Rich

 

[Sonnie Parker]

Yeah... I was at 0 on the SHD when I measured the SPL at my listening position last night. It is not that loud really, and perhaps the 4 volt output of the SHD is the issue. I have switched the voltage on the AHB2's to 2 volts and it is definitely louder, but that's not optimal I would think.

 

[AJ Soundfield]

Impedance plots of each speaker.

15A Notes
4 ohms @ 2.5kHz
3 ohms @ 3.5kHz
2 ohms @ 7.1kHz
1.5 ohms @ 10kHz
1 ohm @ 14kHz
.6 ohm @ 19.5kHz

View attachment 41656

Revel Notes
4 ohms @ 75Hz
3.3 ohms @ 100Hz
3 ohms @ 215Hz
4 ohms @ 400Hz

View attachment 41657

Neither one of those should be driven by bridged AHB2s or any other amplifier than can't seriously drive a 2ohm load.

cheers

 

[AJ Soundfield]

So how do they sound in comparison to the 15A's... hmmm... they sound different. For better or worse... well... I can't say because that might influence Wayne and Dennis one way or the other for our evaluation, so I'll have to wait and announce my verdict after the evaluation. Plus I need more time with the 328's too... this is only one night, and I'd like to hear them both back and forth several times, with and without convolution and Dirac Live.

TO BE CONTINUED AT THE EVALUATION!

You really shouldn't touch anything > 500hz when comparing speakers

 

[Sonnie Parker]

Using my Fluke RMS voltmeter, when I play a 50Hz 0dBFS tone thru the AHB2, the voltage reads 2.87 at -20.0 on the SHD.

The 328 is rated at 91dB sensitivity at 2.83v/1m and is very close to 8 ohms at 50Hz.

When I play the 50Hz sinewave thru the 328 at -20.0 on the SHD... and set the UMIK-2 at 1 meter directly in front of the 328... REW's SPL meter reads 75.6dB and my regular SPL meter (non calibrated) reads 75dB.

 

[Sonnie Parker]

Measurements of both speakers compared.

Click here to download .mdat file for all measurements

 

[Sonnie Parker]

Today after getting things a little more organized, and making sure I had the mic cal file loaded correctly, then after running Dirac... seems louder for some reason... possibly because that area below 80Hz was falling off really steep, and I had the crossover set to 50Hz. Today, crossover at 80Hz... with Dirac... listening to 68 by Lee Ritenour... and SHD at -5.0. Fairly loud and no flashing lights.

 

[Sonnie Parker]

Updated measurements of both speakers.

 

[ddude003]

Pretty incredible how Dirac makes them look the same... Do they sound the same?

 

[Sonnie Parker]

Pretty incredible how Dirac makes them look the same... Do they sound the same?

Dirac up to a certain frequency... then they are on their own... yet they measure very similar at the MLP from about 700Hz on up. We do have the question... is what we are measuring above about 4 times the transition frequency actually what we are hearing? So even with the measurements appearing to be similar, they could sound different to our ears due to reflections influencing the measurements.

I believe there are differences. I won't say what those are until the evaluation... and with more time to confirm what I am hearing on a consistent basis. Unfortunately, there is no way to A/B these quickly whether sighted or blind, since both share the majority of the same positioning/location, and take considerable time to setup. However, I do have SHD presets for each and have at least got it down to only swapping the speakers out to their marked spots... although still about a 10 minute process.

 

[ddude003]

Oh @Sonnie are you suggesting that you can hear something that can't be measured???

I can tell just from the specs that I would not like these F328s... Too much aluminum... Three 8 inch woofers??? And that Waveguide... Thanks and no thanks...

 

[RichB]

The phase looks different but I am not an expert at reading those charts. Humans are very sensitive to phase.

@Sonnie is your room reflective? It looks like you have rugs and maybe a suspended ceiling. The Revels have a wide dispersion which has an influence.

- Rich

 

[Sonnie Parker]

Oh @Sonnie are you suggesting that you can hear something that can't be measured???

I can tell just from the specs that I would not like these F328s... Too much aluminum... Three 8 inch woofers??? And that Waveguide... Thanks and no thanks...

lol... well... I'm not sure it can't be measured... the story may be within those other charts... Impulse, ETC, Group Delay, etc, etc... those appear to be different, and should contribute to the sound.

As for aluminum... the 15A's have two 12" aluminum woofers, so they have more aluminum than the F328's woofers. The waveguide helps with off-axis dispersion... not a bad thing really.

The phase looks different but I am not an expert at reading those charts. Humans are very sensitive to phase.

@Sonnie is your room reflective? It looks like you have rugs and maybe a suspended ceiling. The Revels have a wide dispersion which has an influence.

- Rich

Yeah... I'm not a phase guy either, maybe we can get @jtalden to chime in. As far as I understand it, as long as it is correct for the particular speaker, all is good.

I do have a shag rug over the carpet to help with floor reflections, which we've not been able to determine any reflections from the floor, before I had the rug (according to Wayne). The ceiling is 1/2" sheetrock (original garage ceiling) covered and layered by 3/4" plywood and then covered/layers again by 5/8" sheetrock... painted black. I do have some acoustic panels suspended from the ceiling between the speakers and the listening position.

It's semi reflective as it is now... you can see the ETC charts above which show the reflections. It's not overly reflective from what I can see. I have some materials to make large absorption panels to cover the diffusion panels on the front wall... waiting on the Rockwool to get here. Lowe's is apparently delayed in shipping right now and I can't find what I want anywhere else in small quantities. These will be portable and 7.5" deep. This will allow us to test the sound both ways (absorption vs diffusion) during our upcoming evaluation.

 

[AJ Soundfield]

Pretty incredible how Dirac makes them look the same... Do they sound the same?

I see major audible differences in the same measurements...and the LP ones are 100% why you should never EQ anything >500hz +/- from there, since they are SPL "sums", without any directional info, etc. All discussed in Tooles videos, free papers, etc.
The 1-2m ones gives idea of tonal, but not timbre or spatial. One needs far more data (spin for eg.) to get a clearer pic of sound.
Btw your beliefs about "aluminum" magically disappear in blind tests.

cheers

 

[RichB]

lol... well... I'm not sure it can't be measured... the story may be within those other charts... Impulse, ETC, Group Delay, etc, etc... those appear to be different, and should contribute to the sound.

As for aluminum... the 15A's have two 12" aluminum woofers, so they have more aluminum than the F328's woofers. The waveguide helps with off-axis dispersion... not a bad thing really.

The 328 has 3 8 inch woofers which is the same surface area as a single 15".
Still, the MLs can deliver more and lower bass output using tuned amplifiers that eliminate passive crossovers.
The 328's are tuned for greater efficiency than the Salon2s that have more low frequency output.

- Rich

 

[Sonnie Parker]

Forward radiating woofers on a speaker pulled out into the room like mine will rarely (if ever) give you any extended bass response. Nearly every dynamic forward firing speaker we've evaluated or I've owned is the same... rolls off early. The reason the 15A's have somewhat respectable extension to 20Hz is because they have a rear-firing 12" driver that is 16" closer to the front wall, which gives it better room boundary gain. The only other speaker to do fairly decent in my room was the 11A's, the Montis (both ML's), and the SVS Ultra Tower with side-firing woofers. I don't think I still have those measurements for the SVS and HTS has deleted all of our graphs, so I can't say for certainty.

 

[jtalden]

Yeah... I'm not a phase guy either, maybe we can get @jtalden to chime in. As far as I understand it, as long as it is correct for the particular speaker, all is good.

My thoughts:
I took a look at the mdat and found nothing that stands out in the data as an issue for either speaker. They are very different designs resulting in a different direct sound phase response as well as other characteristics. I do expect a clear difference sound to be identified by all listeners. I think that the different dispersion characteristics within in the room is likely to be main cause of most of the differences heard. It will be interesting to learn which speaker is preferred in the listening test and why.

Regarding Phase:
Poor XO design can lead to problems, but good XO designs have not be demonstrated to cause clear issues. All XO's (in both speakers) appear to have reasonable phase tracking through the XO range.

The 328 has more direct sound phase rotation above 300 Hz as it has an additional XO around 3 kHz for the tweeter. When an XO at this frequency is designed for close phase tracking between the 2 drivers there is little reason to believe that the additional overall phase rotation itself will impact listening preference. The vertical sound dispersion from the vertically offset divers is more likely to influence the sound in some cases.

The Dirac EQ'ed measurements removed the phase rotation of the 3 kHz XO in the 328 anyway so that both speakers phase tracks flat above 700 Hz. Any preference difference in listening done with Dirac active will not be due to direct sound phase differences above 700 Hz. There are differences in phase rotation at lower frequencies as well. There is a somewhat higher possibility that phase rotation there may contribution to sound preference due to the interaction within the room. I would not be able to predict which is more likely to be preferred however.

 

[Sonnie Parker]

Thank you for your input John... much appreciated.

 

[RichB]

The Dirac EQ'ed measurements removed the phase rotation of the 3 kHz XO in the 328 anyway so that both speakers phase tracks flat above 700 Hz. Any preference difference in listening done with Dirac active will not be due to direct sound phase differences above 700 Hz. There are differences in phase rotation at lower frequencies as well. There is a somewhat higher possibility that phase rotation there may contribution to sound preference due to the interaction within the room. I would not be able to predict which is more likely to be preferred however.

Personally, I'd do testing without EQ (Pure Direct) and Dirac.
My experience with Dirac is that even with marked positions on the floor it is difficult to get repeatable results.
So there is no telling if either represents the best Dirac can do.

I only compare speakers without EQ to remove the variable figuring that there is plenty of flexibility for adjustments but baseline performance may not be correctable with REQ. I also, only EQ below Schroeder.

- Rich

 

[Sonnie Parker]

We do both... with and without Dirac, since Dirac will take the room out of play below the transition frequency and let you hear what the speaker company really wants you to hear, and see if it's capable. We don't swap them back and forth during our evaluations... we listen, get it all done and measured, then move on to the next speaker. In some cases we might want to go back and listen to a particular speaker if we have time, but we will rerun the Dirac measurements with the saved target response curve.

Now me... I'll swap them back and forth for my own personal evaluations for what I want in my room... completely different set of circumstances... as I have plenty of time vs an evaluation where we are limited.