Introduction

In a previous blog post, I introduced YPAO R.S.C. (Reflection Sound Control), which is Yamaha’s room equalisation system. If you’re new to room equalisation, please read this post first. I will present some measurements below to show what R.S.C. is doing exactly.

Function of R.S.C.

According to Yamaha, the pure function of R.S.C. is to remove unwanted first order reflections from the sound. This should improve stereo imaging and intelligibility. As we will see there are other added benefits.

R.S.C. filters are applied before any Parametric Equalisation. In fact, all further measurements were taken using the following method on an RX-V3073 (the equivalent of the RX-A3020.

  1. Running a multi-position YPAO with all 8 speaker positions.
  2. Copying the flat curve over to the manual curve. This also copies the R.S.C filters as we will later see.
  3. Zeroing out the PEQ filters manually (to 0dB on all) as this will keep the R.S.C. filters but remove any parametric equalisation. This has also been confirmed by Yamaha Japan – and the measurements that follow.

Measurements

YPAO succeeds in its goals – with some speakers and seating positions better than with others. I will show an example below with a centre speaker measurement. The centre speaker is located underneath a tensioned screen. The speaker is tilted upwards towards the listening positions. However, because of the room dimensions and multiple hard surfaces between the speaker and the listening positions on the sofa, the 70Hz to 250Hz region is a real issue with room modes – peaks and dips galore – that reduce intelligibility and are hard to deal with using PEQ alone.

Frequency Sweep

The below frequency sweep has 1/6 octave smoothing so all that is visible that R.S.C. cut some reflections in the 60Hz to 200Hz region. The green line was measured in the “through” position, while the pink line in the manual setting with no PEQs applied. Please note that R.S.C. is applying some attenuation to the signal output. The attenuation is dependent on the filters applied by the system, so it varies from channel to channel. The graph below has been adjusted to take this into consideration.

It is interesting to note that there is some activity going on above the modal region (above 250Hz). This isn’t necessarily bad as long as the robustness of the correction is taken into consideration. For example, Dirac Live does this across the whole spectrum also, but the higher frequencies are corrected, the more correlation needs to be between samples.

center rsc v no

Now let’s have a look at the modal region with less smoothing to see what’s really going on there. Now this is more interesting. R.S.C. actually dealt with a dip in the 70Hz to 80Hz region, where the subwoofer crosses over to the centre speaker and removed some frequency build-up because of the back and side walls between the 80Hz to 200Hz.

center rsc v no v2

So what is actually going on in the 70Hz to 80Hz region? Obviously no PEQ filter would be able to fill that region in since waves are cancelling each other out – as that has been tried before on this set-up. Let’s have a look at what is going on in the phase of the signal to answer that question.

Phase Measurements

As can be seen in the below measurement without any R.S.C. filters applied, there is a phase shift in the crossover region. This is quite common.

center phase no eq

As can be seen in the below measurement with R.S.C. applied, the subwoofer and centre speaker phase are better aligned in the crossover region, therefore removing the dip in the frequency measurement. So far so good.

center phase rsc

Ringing

Finally, let’s look at the spectrogram to see whether ringing has been improved. To be honest, ringing wasn’t much of an issue for this speaker / seating position. But as we can see in the after diagram, the crossover region looks a lot smoother and overall sound pressure levels have been better equalised in the modal region.

center spect no eq

center spect rsc

Subjective Listening Tests

After the above measurements were made, the PEQ filters got re-applied that smoothed the frequency response out, now having a much easier job of doing so.

Having the same PEQ applied over R.S.C. and no R.S.C. filters, though not a perfect test, the sound with R.S.C. filters applied just seemed more 3 dimensional with a better stereo image from the front and surround channel pairs. The sound of the centre channel is also improved in terms of smoothness.

What’s also clear is that the bass region is improved in terms of tightness. Even though amplitude was corrected with PEQ filters, the bass still sounded boomy in some listening positions without R.S.C. applied.

Tips and Tricks

The above does pose a challenge for those that like to have the Yamaha presence channels going along with the base 5.1 or 7.1 set-up and want to do a “full manual” configuration with R.S.C. applied. How do you measure the frequency response of these speakers after R.S.C. has been applied? Here’s a neat trick:

The easiest is to feed the left, right or surround left and right speakers with the frequency sweep signal while having the receiver in 9 channel / 11 channel stereo mode.

To hear the signal only come through the corresponding presence speaker, configure the 9 channel stereo to maximum high balance, maximum strength and maximum front / rare – left / right balance as needed. This will channel around 80% of the energy through the measured speaker, which is good enough to get an accurate measurement.

Happy Listening!

45 Comments »

    • I think that’s a more complex question than just looking at charts. Both have their pros and cons, but I think it comes down to this:
      if you want to see what the auto-setup routine is doing and tweak it to your preference, then YPAO will serve you better. If you just want to set it and forget it, XT32 does a pretty good job.

      I will say this, though: even XT32 will be somewhat different in a Denon or a Marantz for example, in how it sounds. I recommend auditioning a whole package, as opposed to just looking at the room correction. If you want room correction that does an excellent job with a difficult to correct listening environment, you would go for something like DIRAC LIVE and forget about both XT32 and YPAO to be honest. For 99% of people, either will do fine, with the exception that YPAO does need manual subwoofer tuning.

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      • I already have Dirac Live but it has too many disadvantages like not supporting multiple subwoofers, can’t tune crossovers without full recalibration, etc. Additionally it won’t work with AirPlay unless I have an AirPlay receiver BEFORE the Dirac Live stage. The PC version has many bugs like not starting automatically, doesn’t support all ASIO devices, games lose OpenAL support etc.

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      • Re Dirac live, there’re only two other ways to take advantage of it: buy a receiver with it (Emotiva or Datasat) – or buy a miniDSP product. If you have a lot of money, you can buy separate amplification and stick two channel dirac live hardware between the components per pairs of channels.

        Well, XT32 will give you better results for your subs out of the box, not necessary for the higher frequencies. I wouldn’t call YPAO bad out of the box, but certainly won’t give you the results with your subs that you require.

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      • I can’t image how XT32 could differ between Marantz and Denon. The firmware is identical with just the logo and colour theme changed. If anything, it’s due to analogue component differences.

        I need something that will automatically correct multiple subs, right from 15 Hz upwards and work universally for all input sources. It should not require manual tweaking because the default calibration is “bad”. I get the impression that YPAO’s default is “bad” compared to Audyssey but it can be made better only through manual adjustment.

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    • If you adjust the EQ manually, you will need to re-calibrate speaker-levels, yes. When it comes to crossover, use your better judgement according to your measurements and EQ adjustments. Distances should not need any tweaking.

      Like

  1. How low in frequency would a yamaha rx a3030 phase adjust? How low in frequency can you manually adjust? I am trying to decide on XT32 or YPAO. Thanks. Great work!

    Like

  2. Sorry, it’s late. What I meant to ask is: 1. How low will YPAO (rx a3030) do impulse response calibration? 2. How low in frequency can you manually adjust the PEQ? 3. Will YPAO level and phase match multiple subwoofers? Thanks.

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  3. Hello and sorry for my poor english.
    I have a question about YPAO R.S.C. Is there any recommendation about mic placement for measurement. For example, for the first measure. It’s best to take mic on the center of the listening area or in the center of front speaker (my sofa is not aligned). And for the next position is there any recommendations (2 feet on the right or the left….) On the manual the bests positions are not clearly indicated.
    Before this yamaha amp, i have an onkyo with audyssey and mic placement are very important for correct measurement.
    Thanks in advance

    Cordially

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  4. Starting with the new Yamaha RX-A850 and above, they state that there is “subwoofer EQ”. That is not present in the RX-A750. Anybody have any experience with performance?

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  5. How exactly do you use the YPAO RSC mic, with REW? Doesn’t It require a calibration-file in REW to function accurately? I am trying to tweak my RX-A3040 with REW, but I’m a bit confused about the method to do this. I will be using a Lenovo laptop, with a pretty descent on-board soundcard which has mic-line in and HDMI-out…

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    • Yes, a calibration file would be ideal, however, I measured the latest Yamaha omnidirectional microphones against a calibrated UMIK and the results were almost identical apart from the low (under 40Hz) and high end (above 15KHz) and even there the deviation wasn’t more than a couple of dB. Now having said that, it is worth investing in a calibrated microphone if you have the cash. It will give you a lot more accurate results. The Yamaha mic should get you started, though.

      You should be able to attach the mic to the line in on your sound card. If not, buy a USB sound card off eBay that splits the mic in and line out. The mic will likely not work with a port that combines both.

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  6. What are your thoughts on YPAO for stereo-listening of music. I’m somewhat pleased with what YPAO does for me in 7.1, but my troubles begin in stereo. The sound seems very “digitized”. Way too much for enjoying music. I currently use the “pure-direct”-setting to fix that. But I can’t stop to wonder, if I would get to a higher audiofile level, by doing a manual calibration, for stereo only…

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  7. Roland,
    I have read some other experts with your level of understanding of these issues, and have found other sources that wrote so clearly, but yours is the only source I’ve found that provides the discernment *and* the clarity. Thank you so, so much.
    A question: I have for many years used a Rane analog parametric EQ (upstream of my sub) to manage my listening room’s very large room modes. This has worked very well. A week ago I purchased the RX-V679 in hopes of finally doing the parametric EQ’ing in the digital domain. To my surprise, in this receiver’s on-screen setup menu, there is no option for PEQ for the subwoofer. (All other 7 speakers are afforded 7 bands each of unique PEQ, which is wonderful, but no PEQ option is available for the subwoofer.) The subwoofer is definitely operational, and the receiver definitely knows it exists (because I can select its distance, the configuration is set to 7.1, etc.). It seems like everybody would especially want PEQ for their sub. So am I misunderstanding something?
    Thank you again for providing this truly exceptional resource.
    Nom

    Like

    • Thank you for that kind feedback, nom.
      With regards to the RX-V679, it may not have EQ for the subwoofer channel. I know one model up, the 779 has it. Check that the subwoofer is indeed enabled. If the subwoofer doesn’t show up in the equalisation section on either the on-screen controls or the web interface (/setup/ – mind the second / after setup!!!), then the unit doesn’t have subwoofer EQ.

      If that is the case, you have a few options:
      1. Return it and get the model up. This is going to give you acceptable sound.
      2. Buy a miniDSP 2×4. This is a more flexible option and with a bit of know-how, you will get better sound than with option 1.
      3. Try and find a used SVS AS-EQ1 on the forums (e.g. AVSForum). This is going to give you the best sound. This is what I use at the moment, and it is a phenomenal piece of kit! I don’t like Audyssey for the main channels but for the subwoofer channel it does work very well. I hope this helps!

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      • Thank you so much for the workaround options, Roland. I was really hoping for a one-box solution this time, as I value audio simplicity more and more as the years pass. I’ll double-check, following your tips, but I’m pretty sure this model just doesn’t provide for subwoofer channel PEQ. (If I’m right, it’s just baffling to me, since the sub channel is, most often, the one that spans the major room mode, usually somewhere between 50 and 70hz. It’s the single most important use of PEQ.)
        Fingers crossed, and thanks again!

        Like

  8. Great info! I’m using REW with a Umik-1 to fine tune my A2050. I understand the process with the exception of getting customized PEQ results in REW. Which EQ do you use? I’ve tried multiple options but can’t seem to find anything that matches up with the available adjustments in YPAO. Thanks!

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    • You can’t use the automatic filter generation in REW. You have to manually find the best nearest filters. You could do this by trying the nearest approximate after auto filter correction in REW. I hope that makes sense.

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  9. I have just picked up a used svs as-eq1 to use with my yamaha 3060. How do you recommend to set it up? Should I run the eq1 then run YPAO over the top of it. I could copy the YPAO results to manual and remove any PEQ set for the sub so that YPAO is only setting distance and level.

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    • It’s funny because I have an SVS ES-EQ1 that I run with it as well now. It’s the best setup.

      I didn’t use the EQ assist feature, but ran YPAO with the subwoofer off, then I manually turned it on making sure there weren’t any EQ adjustments.

      Then I ran through the SVS setup using the level matching function with the front speakers and then did the SVS EQ routine.

      The results are excellent in spite of a non-ideal sub location.

      Like

    • Oh one more thing… don’t run ypao for the sub because you cannot remove all filters. The impulse correction cannot be seen or removed on the front-end of the Yamaha.

      Distance will be corrected by the SVS routine.

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  10. Just to make sure I am understanding correctly, I should tell my 3060 that I don’t have a sub then run YPAO. After it finishes, I should then go into manual setup and tell the yamaha that I have a sub. I then run the the SVS EQ routine.

    Is this correct?

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      • I have the DSPeaker AntiMode SII to EQ my sub. Would you recommend the same order of setup for that too?

        Just, DSPeaker say to EQ the sub, then YPAO after, as YPAO “sees” the AMSII correction, and doesn’t attempt to do its own.

        Though from experience I can see my most recent run of YPAO {minutes ago}, it didn’t EQ the sub until the 250hz region, which also happens to be where AMSII stops its EQ.

        This is using a Yamaha RXA 3040 {using YPAO + RSC}, powered by Yamaha’s MXA5000 = A total beast…and I LOVE IT! ;o) \nn/

        Doing it from the ground up makes sense, as it’s the low end that {when it’s a poor EQ for subs, such as it YPAO} that suffers and the modes mask so much detail; makes for a smoother transition through frequency sweeps.

        Whereas working from the top down shouldn’t {in theory} result in as smooth a slope, as YPAO’s already EQ’d down as the speakers/ room allow, therefore a sub EQ would just be “fitting in” where ever you XO the Fronts from

        Your thoughts?

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      • Hi Paul,

        My experience with using a separate EQ for the sub is that you get the best performance by doing the following:
        1. EQ with YPAO first by turning OFF the sub so there’s no correction applied.
        2. Turn on the sub in manual setting in the receiver and the sub itself.
        3. Now use your subwoofer EQ to do its thing and ensure you match levels afterwards.

        If your subEQ doesn’t allow for delay compensation using its routine, you may need to do a calibration with YPAO with sub on, write down the distance measurement and then do the above plus amending the distance for the sub from the first run before you EQ the sub.

        I should write an article about this as others have also asked! I’m not making a lot of sense today tho. Let me know if the above is not clear.

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      • Yeah, it’s clear and simple enough, it’s just it’s the opposite of what the makers of the Anti Mode {DSPeaker} say themselves, so makes me wonder if their choice/ advice of setup only really applies to AVRs that have no sub EQ at all, and thus, would have no chance if it interfering with YPAO, therefore your method working best with AVRs that do have some form of sub EQ.

        A comparison using REW would be helpful in showing the difference in the methods used.

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      • Unfortunately, I don’t have measurements to back this up at this point. However, my experience with an SVS AS-EQ which has Audyssey X32 is that YPAO will still try and correct over the already corrected curve. The YPAO routine is not nearly as sensitive or sophisticated in the low end as Audyssey unfortunately. I don’t want YPAO to touch anything below 80hz at this point, basically. The result is very well integrated, well beyond what I could ever achieve with YPAO.

        In fact, SVS provided a routine for the subEQ to bypass any receiver’s correction for the sub so there are no overlapping filters applied. You could try it both ways and see which you prefer. But maybe you should follow the manufacturer’s advice first and then go to the second option if that doesn’t produce satisfactory results. I hope this helps.

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      • Considering the SVS EQ has AX32 built~in you’re already onto a winner, since that apparently beats pretty much all sub EQ’s anyway, including my AntiMode SII, which is why those with AVR’s that already have Audyssey XT32 in them {such as Onkyo} have no need for further AntiMode devices

        So since your AVR’s a Yamaha, you’re getting the best of both worlds! Moreso since the SVS EQ’s no longer available, for the most part.

        Shame Yamaha can’t get their shit together/ put ego aside and form a deal with the likes of DSPeaker/ SVS and get that built into an AVR.

        It’s a shame that more people don’t know what they’re missing out on; you can spend £1000’s, even £10,000’s on equipment, but the room it’s in is killing the quality due to modes etc, even in spite of your best efforts with placements etc

        When I got my first AMSII I remember it did 2 things: 1) Brought tears to my eyes and 2) Had me smiling/ laughing for days after. The difference was/ is night & day, with movies, music… anything that involves sound, basically

        Now, I tried your method earler, and I really can’t tell a difference, personally. Could be down to our differing rooms, equipment, speakers, just so many variables.

        What I do know is this, if someone has a worthy subwoofer, they need an AntiMode, it’s that simple! They take a great system and make it sound fucking amazing, and could potentially save you spending money in places {room treatments, bigger speakers} they just don’t need!

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      • Yes you are right. I have the best of both worlds.

        I’m having direct contact with Yamaha Japan for a deep dive into their newly designed sound field and 64bit YPAO for the month of June. I’ll bring their attention to the shortcomings and hope they will start turning the gears on this. There are two major issues I see still with their receivers:
        1. Sub EQ that is lacking in performance
        2. Not changing the volume of the surround speakers relative to the front dependent on volume. It is crucial for integrity of the sound stage in my experience.

        The 3rd – loudness compensation (YPAO volume) – they have already sorted.

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      • 64bit YPAO sounds interesting. What is it currently, 32bit?

        Your #1 issue definitely needs fixing, and long overdue too. Considering how much a good subwoofer EQ improves the overall sound quality so dramatically it should’ve been a priority long ago; not more gimmicky sound profiles that no one really uses on a regular basis.

        I mean, during the mastering/ mixing of audio for DVD/ Bluray, the sound engineers are already going to great lengths to make it sound as good as possible for playback at home {most the time anyway}.

        I’ve used them myself a few times, but since YPAO is already catering your speakers to your surroundings anyway it doesn’t really seem necessary to have anything other than “Straight” and Pure Direct as your main options, beyond YPAO; it’s like adding an extra lot of processing {Original recording – Studio Mastering for home – AVR processing – Final output}.

        Not sure I’m with you on #2, as soon as you increase the volume it increases every speaker. If Surrounds are too loud for your tastes {after EQ}, simply turn them down for a more diffuse sound. Maybe it should do this automatically during calibration, like if it senses your Surround speakers are too close to your head {mine are at ceiling height, on their sides, and slightly inverted, for instance} and it sounds great, the height doesn’t ever detract from it, because the delay is taken into account. If anything, it’s more immersive by being “showered” in sound, but also very direct when it needs to be.

        And as for YPAO volume, it seems to do very well at keeping everything level, regardless of the volume {I never need to go above -17db… and I like it LOUD, and in a 10ft x 10ft room!}, and I think that’s automatically switched off the closer to Reference volume you get, then would re-engage below that, from videos I’ve seen demonstrating it.

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      • Hi Paul,
        I’ve published a new article today on Configuring YPAO. Have a read over it. It does talk about some of the above. Thx 🙂

        Like

      • Roland, I agree that Yamaha needs to improve their sub EQ. I had to add a SVS EQ to my 3060 to get the results I wanted.

        I disagree with changing the level of the surround speakers relative to volume. I don’t like that at all. If you look at AVS forum, you will see that that is the thing most people seem to complain about with Audyssey’s Dynamic EQ. At the very least, I think the surround boost should be separated from the frequency compensation. Boosting the surrounds always caused the sound stage to be pulled to the rear in my setup. I find this particularly undesirable if one has an Atmos setup or uses presence speakers.

        Since you seem to have direct contact with Yamaha Japan, Could you give us some more detail as to how YPAO Volume works? What does it use as a reference to know how much boost to be applied? How does it compare to Dynamic EQ? Since it doesn’t use any level offset, how well does it work with different sources.

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      • Hi Tony,
        I use an SVS as well with my Yamaha. It’s great!!!

        I find surrounds always too low at lower listening volumes (-25 and below), not only in my setup. But it depends on a lot of factors. I agree it should be configurable and separated from loudness compensation (such as YPAO Volume).

        You’ll have to wait for the YPAO volume write-up for end of June / early July. I’ll make sure to ask and include those questions. Thx

        Like

      • Btw, if you don’t hear a difference, then just go with what the manufacturer recommends, just to be on the safe side. Easy as! 🙂

        Like

  11. I took your advice setting up my SVS EQ1 and it sounds great. I have another question. YPAO set PEQ filters on my left/right/center channels down to 63hz. It set them to large but I use an 80hz crossover to take advantage of the better SVS EQ in the lower frequencies. I prefer the natural PEQ curve. Should I copy it over to the manual PEQ setting and zero out the PEQ adjustments YPAO mad below my crossovers?

    Like

    • It’s not necessary to do that. Simply set the crossover frequency. The Yamaha is smart enough to do a soft roll off at the crossover. I wouldn’t mess with PEQ adjustment at the crossover point otherwise you could mess up the frequencies around it.

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  12. Hello again Roland,

    I find myself in the same situation as Paul McKenzie; I have the same DSPeaker EQ. I want to reproduce your most successful protocol, but I didn’t understand your second step. I’ve reproduced your steps below, with the part that confuses me set off with asterisks. I just don’t know what you mean by “in manual setting in the receiver and the sub itself”:

    “Hi Paul,My experience with using a separate EQ for the sub is that you get the best performance by doing the following:

    1. EQ with YPAO first bu turning OFF the sub so there’s no correction applied.
    2. Turn on the sub ** in manual setting in the receiver and the sub itself **.
    3. Now use your subwoofer EQ to do its thing and ensure you match levels afterwards. ”

    Thanks so much,

    Art

    Like

    • Hi Art,

      No worries. When you EQ with YPAO you turn off the sub completely. This means that YPAO will think you don’t have a sub. So in the second step you need to turn on the sub at the switch on the sub as well as go into the receiver settings (it says auto or manual speaker settings – you go into the manual section) and under configuration, you turn on the subwoofer. I hope that helps.

      Thanks

      Like

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