Are early reflections perceived as direct sound (in the context of stereophonic reproduction)?
Yes, see https://en.wikipedia.org/wiki/Precedence_effect for more info.
Are early reflections perceived as direct sound (in the context of stereophonic reproduction)?
(Okay, actually it's two angles, because there are two speakers when listening in stereo. My point still stands, though. Come to think of it, maybe that's partly why we are more discriminating in mono listening than stereo listening!)
The discussion was originally about whether the Listening Window average is a representative measure of the direct sound.
The way I see it this discussion was whether LW better correlates to our perception of optimal SQ vs the on-axis.
Well that depends: by "on-axis", do you mean the angle at which you happen to be listening at right this moment, or do you mean the specific 0° on-axis measurement?
If it's the former, then I really don't see how the answer could be anything other than "no", from first principles of how sound propagation works.
If it's the latter, then we're back to the discussion of whether the averaging used in the calculation of the LW makes it a worse predictor than the 0° measurement, even when potentially listening slightly off-axis. To be clear I don't know the answer to that, but I take issue with assuming it isn't without evidence, as @jhaider just did in the post above yours.
No. But I have purchased the Revel F35 which just arrived. And M8 SP2.
At the end this all ends up on our personal preferences because as soon as we get the chances to move LF and HF sliders we will adjust it as we personnally see fit. And once more, at the end it all happens in our rooms: with 20-300Hz range it is quite easy - make steady state measurement and correct it. With 300-900Hz it is pretty much the same, but to a lesser extent. It is with 900-20000 where things are getting really complicated: do you aim for (pseudo) anechoic flat response or you aim to linearise steady state response. Probably there is no answer that suites all, so what is your prefence? Maybe if you show us your corrected in-room measurement we will get a better picture than from repating Toole's quotes, which btw even the Harman's engineer don't blindly follow.
To be clear, when I say I'm worried about the averaging used in the LW, my worry is about relatively high-Q anomalies, not the overall trend of the frequency response (which likely won't be affected by averaging, anyway).
With that in mind, I'm deeply confused as to why you are bringing up "personal preferences", "LF and HF sliders", "steady state measurements" and "in-room measurements", all of which are completely unrelated to the point I'm trying to make. (Did you mistake this conversation for the parallel one we're having about PIR?)
Well, one can think of eventual high-Q anomalities getting lost in averaging as a good thing as that is only becaus of their relative insignificance.
I'm trying to see these 2 topics (anechoic spinorama and steady-state based room EQ) as one thing.
Ooh very interested to see how the F35's measure, and how they compare to the M16. Also curious to see how the 2.5 way design works, and what disadvantages it has compared to a 3 way design like the F206.
It's a phase cancellation. Treatment will be of little effect. If the lobe was pointed upward then ceiling treatment may help; however a design like that is intended to give better vertical coverage for a standing listener.Come again??? No one has said the floor or the ceiling are the cause. What is said is the to the lobing that exists, you want to reduce those reflections. Once there, their effect is lowered.
I'm trying to see these 2 topics (anechoic spinorama and steady-state based room EQ) as one thing. Based on that perspective I have tried to EQ my speakers in the 900Hz-20kHz range based on flat on-axis measurement (my gated NF measurement turned out pretty much the same as "official" spinorama on-axis measurement) only to find out that to me it sounded inferior to EQ adjusted with HF shelving filters so suit my personal preferences. If that is true for most people it will make spinorama only a tool to choose loudspeaker but without any practical use when putting it in your room and doing room EQ.
The treatment is not to fix the hole, but to reduce the impact of all reflections in that direction which are not tonally similar to direct sound.It's a phase cancellation. Treatment will be of little effect.
How did you do your comparison of each EQ type? I used to EQ above transition based on in-room measurements but now use anechoic measurements to flatten out the listening window, they are similar filters since the same peaks show up in my room curve but the anechoic filters sound slightly better to my ears. The main thing is to have anechoic measurements to ensure any EQ you do won't negatively affect the off-axis sound, even if you are using a room curve for the EQ.
Thank you for the review. They are nice speakers. If anyone is interested in trying pretty much the same speakers for $160 for the pair go to https://www.harmanaudio.com the infinity R162s are on sale for $160 for the pair. This would be a great way to compare the trickle down engineering from the Harmon audio team. I believe they are basically very similar speakers.This is a review and detailed measurements of the Revel M16 stand-mount/bookshelf speaker. I purchased this through my company and it arrived a few days ago. Can't tell you my cost , but retail price is US $900 (sold $450 each).
As you can expect, when you pay more, you do get more as far as overall look and finish of the speaker:
No fasteners, finish that let you read your smartphone against, etc. Curved sides lead to the back panel:
Large curved port and quality binding posts.
Disclaimer: Before I get into this review, and at the risk of stating the obvious, I have a million conflicts of interest here. I am a long time friend and professional colleague with a number of Harman employees (parent company of Revel). I have praised their design and research philosophy countless times. And our company, Madrona Digital is a Harman dealer (although we hardly sell any stereo gear). So read all the bias you want into the review but please don't go posting to complain. Just read the measurements if you are worried and if you don't trust that, just move along.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
All measurements are reference to tweeter axis with the grill removed. Frequency resolution is 0.7 Hz (yes, less than 1 Hz) and plots are at 20 points/octave. Spatial 3-D resolution is 1 degree.
Over 1000 points around the speaker were measured (from 20 to 20 kHz) which resulted in well under 1% error in identification of the sound field across full frequency response of 20 to 20 kHz. Final database of measurements and data is 1.4 Gigabytes in size. As you see below, I also made a scan using 500 points and results were identical, pointing to a well behaved soundfield that is easily to synthesize.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
View attachment 52899
At first blush it seems that the response is not flat but if you ignore the hump at 100 Hz and roll off above 10 kHz, the rest is actually pretty close to flat. So tonality should be neutral but with some boosted bass. The high frequency roll off was puzzling as it doesn't match Harman's measurement:
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As I have circled, the Harman measurements seems to be some evaluation version? Perhaps there has been changes since? Regardless, the rest of the measurement matches mine quite well so confidence is high in the data you see here.
Above data is for a reflection-free room. We can however simulated what happens in a typical room using Predicted in-room response which is right on the money with some bass boost:
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Given the bit of roll off in high frequencies, don't go putting absorbers everywhere, especially the thin ones.
We are done here. Speaker nerds can read on though.
Basic Speaker Measurements
Speaker phase and impedance shows one resonance which shows up in other measurements including our spinorama shown above:
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You can see it here as well:
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The crossover is at 2.1 kHz and we see rising distortion prior to that. Seems like the woofer is breaking up before its shift is over.
Everybody get ready to say "oooh" as I post the pretty waterfall graph:
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I know, not as exciting in person.....
Advanced Speaker Measurements
You can tell someone was making sure that the sound you hear reflected horizontally is just as perfect as the on-axis direct sound:
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You paid for it, might as well use it so don't cover the sidewalls. Let the speaker use them to present a larger image.
We have our vertical dip at extreme angles so floor and ceiling should be covered if the room is not too dead already:
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That would reduce the dip in vertical axis around crossover region as marked.
Sitting a bit to the side (not as much toe-in) fixes that little hump around 5 kHz:
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Eye-candy Speaker Measurements
Our horizontal directivity plot shows that this speaker has similar tonality to +- 60 degrees and rolls of very smoothly:
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Note that the above has 1 degree spatial resolution so much, much more detailed image than what you see even coming out of anechoic chamnbers.
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Speaker Listening Tests
I first started testing the M16 on my desktop in near-field listening, comparing it to cheap Pioneer SB-22 speaker (levels matched, one speaker at a time). The Pioneer just wasn't in the same class. It sounded tinny and small compared to Revel. Pushing the M16 hard, I could get the small woofer to distort. Since this is not a near field monitor, I decided to test it in my 2-channel system as I have tested other hi-fi speakers. Here is what that looks like:
View attachment 52913
Sitting next to its much bigger brother, the Revel Salon 2, it seems that the M16 won't have a chance. Boy, is that the wrong conclusion. Vocal fidelity in both male and female tracks was excellent. Such balance and what I focused on when I took the blind test at Harman. And then these delightful highs would come with such clarity and freedom of distortion/coloration that would melt me in my chair.
I sat there going through my reference tracks, one by one, and almost all sounded superb. Despite only one speaker playing, if you closed your eyes, you absolutely heard a "soundstage" as if there were two speakers playing and creating a large phantom image. Yes, the bass at times was a bit much. And max SPL was not there. But boy, was it close to my much larger speakers for general enjoyment. I usually play half a dozen tracks and I am done testing speakers but not here. I could not stop.
Conclusions
If you want to have a taste of what all of Harman research and engineering is about, get a pair of M16s and listen. They are delightful "bookshelf" speakers showing what can be done when you combine serious research with a decent budget for pats and manufacturing.
Truth to be told, I tried, I really tried to give the M16s the middle of the road award so that I would not be accused of bias. But at the end, I just could not. These are wonderful sounding speakers. It is what "high-end" sound reproduction is about in smaller budget. The combination of measurements and subjective listening impressions left me to no room but to give them my highest award (in the context of a small, lower cost speaker).
Needless to say, I am happy to recommend the Revel M16 speakers.
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As always, questions, comments, recommendations, etc. are welcome.
Had to ask my guy who does yard work to come and do what I should be doing there, instead of testing audio products. Feels good to not kill my back doing what he is about to do. Then again I look at my bank account and get depressed. Make me feel better by donating what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
As an owner of both I find the 35s to be very similar, with increased efficiency per spec and (to my ear in my room) slightly better resolution in the vocal range but slightly less 'body', like a bit of a shift towards a smoothe presentation while the M16 is perhaps tweaked to sound a bit bigger in the low mids. Pure speculation on my part though and could easily be in my head and/or impacted by positioning in my room rather than the speaker itself. Bottom line is I am more than pleased with both, as you are with your F36s.
I don't think they are similar at all. That said, I have purchased its tower version so we will see.Thank you for the review. They are nice speakers. If anyone is interested in trying pretty much the same speakers for $160 for the pair go to https://www.harmanaudio.com the infinity R162s are on sale for $160 for the pair. This would be a great way to compare the trickle down engineering from the Harmon audio team. I believe they are basically very similar speakers.