massive peaks and dips in measurements, how much actually matters?

[No_hair_left]

So Im using some q4 metas as left and right channels with an r2 meta, after taking some measurement I am seeing huge dips and peaks. My left and right seats are 35degrees off axis and the mlp puts them at about 20degrees of axis.

The first picture is the left speaker while in the right seat so 35d off axis,

even on on some measurements like the left seat left speaker one (which puts it at 10degrees off axis) it still exhibits these massive peaks and dips. Is this the speaker boundary interference people talk about when wall mounted? or maybe because I have 0 room treatment? most of it seems to be under 500hz apart from the center channel left seat picture, that shows something going on between 1-2k.

Does any of this stuff actually matter lol?


One last question is there any way to get the soundstage more centered for the left and right seats other then crossfiring the speakers? if I sit in the left seat the sound is obviously biased to that side because Im closer to the front/rear left side.

 

[Digital_Thor]

Better damping in the room, so yeah... you answered your own question
Several subwoofers could smooth out the response below around 100Hz, but that trick is not gonna take care of the 100-500Hz - damping will

 

[Heinrich]

Better damping in the room, so yeah... you answered your own question
Several subwoofers could smooth out the response below around 100Hz, but that trick is not gonna take care of the 100-500Hz - damping will

To treat the room would perhaps worsen the bigger problem of recessed upper midrange response. The bass is ‚normal‘. But I‘ve to say that I‘m not the biggest fan of the new Q series either. Would it help to toe in the speakers?

Is an equalizer at hand, and not the least, we, as Harman apologists, would focus mostly on the direct sound, not the ‚steady state‘, diffuse field response. REW is not the most handy tool when it comes to time windowing.

 

[Blueprint]

SBIR is largely negated (back wall SBIR is anyway) by wall-mounting, so the issue is room modes. Use REW Room Sim to identify good placement along your front wall. You can also use Harman’s room mode calculator, which has always worked better for me. If you’re wed to the position of your speakers as people often are with wall-mounted speakers, move your listening position slightly forward or slightly back, and remeasure.

The issue is that wall-mounted speakers energise all length-wise room modes. That means that you need to be very careful how far you sit from your back wall. You want to sit in a position that is neither a peak nor a null. The first and second order modes are more problematic because they are lower in frequency and therefore can stack, leaving huge peaks and dips.

In the long run, if you have the ability to, and you’re wed to your on-walls, placement of two subwoofers, one in the centre of your front wall and one in the centre of your back wall, will solve a lot of these problems. Good luck.

 

[Digital_Thor]

If they need toe in, you need a flexible wall mount... Which they do not seem to have.
Did you try and put your room in REW room analyzer?

 

[Digital_Thor]

Also.... When you measure, you can only measure all bass below around 2-300Hz together from all sources. Above, you need to measure each speaker individually.
Wavelength in relation to frequency, is both your friend and enemy....

 

[Heinrich]

SBIR is largely negated (back wall SBIR is anyway) by wall-mounting, so the issue is room modes. Use REW Room Sim to identify good placement along your front wall. You can also use Harman’s room mode calculator, which has always worked better for me. If you’re wed to the position of your speakers as people often are with wall-mounted speakers, move your listening position slightly forward or slightly back, and remeasure.

The issue is that wall-mounted speakers energise all length-wise room modes. That means that you need to be very careful how far you sit from your back wall. You want to sit in a position that is neither a peak nor a null. The first and second order modes are more problematic because they are lower in frequency and therefore can stack, leaving huge peaks and dips.

In the long run, if you have the ability to, and you’re wed to your on-walls, placement of two subwoofers, one in the centre of your front wall and one in the centre of your back wall, will solve a lot of these problems. Good luck.reb

I‘m pretty much sure, it is not actually in the wall mounting, but at the wall standing. Anyway, all those advice, not picking at you in particular, on where to seat and what to look at etc, it is not sustainable. Moving the sofa - is a sofa even legal as a listening chair for stereo/surround? Take a seat just a foot off-center, and all the imaging is, well, off.

 

[No_hair_left]

I did originally have the q4 meta on floating bookshelf's to toe in/out but I found it made very little difference. purple was 5 degrees off axis red was 20 from mlp, I figured seeing as it was roughy the same I would wall mount as they look much better like that. I just wish the things had vesa 100 mounts, I was going to switch them out for some ascendo p6 narrows but again they have no vesa mounts and I doubt they are £1500 better then these.

I am pretty much at where I can be with the sofa, the atmos speakers and wall mounted tv dictate where the speakers or sofa can go

 

[Blueprint]

I‘m pretty much sure, it is not actually in the wall mounting, but at the wall standing. Anyway, all those advice, not picking at you in particular, on where to seat and what to look at etc, it is not sustainable. Moving the sofa - is a sofa even legal as a listening chair for stereo/surround? Take a seat just a foot off-center, and all the imaging is, well, off.

I have no idea what point you’re trying to make. The poster has room modes. He also has wall mounted speakers. His solution is subwoofers and moving the listening position.

 

[Keith_W]

One last question is there any way to get the soundstage more centered for the left and right seats other then crossfiring the speakers? if I sit in the left seat the sound is obviously biased to that side because Im closer to the front/rear left side.

Please read the PDF linked in this post about toe-in and how to minimise seat to seat variation. Sometimes the room makes it impossible, but you may be able to improve your situation.

 

[Jim Creek]

It takes at least a 3db amplitude change for acute hearing to perceive a difference in loudness. The actual difference of 3db is a very tiny change in loudness as perceived by an acute ear. A jagged frequency response that changes by 2db to 4db really doesn’t amount to much in IMHO. A perfectly flat frequency is desirable but not necessary to enjoy your speakers.

 

[Heinrich]

I have no idea what point you’re trying to make. The poster has room modes. He also has wall mounted speakers. His solution is subwoofers and moving the listening position.

... I would wall mount ...

@No_hair_left , how are the speakers mounted, in the wall, so that the baffle is flat with the wall? Do you have access to measurements of the direct sound at your listening position, implicating time windowing techniques?

Anyway, the problem is not the ragged response in bass; it is perfectly normal, expectable, cannot do anything about it, and is easily overheard with real content. The problem is the sagged-in response in the mids.

 

[No_hair_left]

@No_hair_left , how are the speakers mounted, in the wall, so that the baffle is flat with the wall? Do you have access to measurements of the direct sound at your listening position, implicating time windowing techniques?

Anyway, the problem is not the ragged response in bass; it is perfectly normal, expectable, cannot do anything about it, and is easily overheard with real content. The problem is the sagged-in response in the mids.

Whoops they are wall mounted, they both clear the tv to the side, I have a measurement mic and rew, no idea what windowing techniques is though.

By sagging response you mean from 2-10k right? the u shape it makes. I could never work that out as when I look at the white paper it has some sort of dip from 1-2k but then it recovers

 

[Heinrich]

Whoops they are wall mounted, they both clear the tv to the side, I have a measurement mic and rew, no idea what windowing techniques is though.

By sagging response you mean from 2-10k right? the u shape it makes. I could never work that out as when I look at the white paper it has some sort of dip from 1-2k but then it recovers

Only speculating, thank you for the input: what we get in the standard spinorama reflects a (halfway) free standing speaker. In contrast to that you use the speakers at (!) the wall, while the front baffle is not flush / on same level with the wall. So, there is a difference. The linearity of frequency response, both in the reflection free (direct) amplitude response, and to a lesser degree in the 'steady state' is affected.

From theoretical reasoning I would expect, that the bass and lower mids get a raise by about 3..6dB, which is a lot. Additionally you get some interference in the lower mids due to edge / backwall reflections. Could be we see that in your measuremensts.

Recently, under strict refusal by the DIY community, I designed a speaker that copes with the situation. I attenuated the lower mids around 300 ..1kHz Hz accordingly - by ear. There are no rules, and more than others you are asked to address the sound balance using a pinch of personal judgement. That's perfectly fine for me, it won't risk your health either, at least not severely.

According the bass in itself, I live with such responses all my life, and survived. The ruggedness roughness can be mitigated, but that would need immense effort for no real subjective improvement after all.

Hope this helps ;-)

 

[dualazmak]

Just for your possible reference and interest, my below posts on my project thread will give you some suggestions for improvements, I assume and hope.

- Not only the precision (0.1 msec level) time alignment over all the SP drivers but also SP facing directions and sound-deadening space behind the SPs plus behind our listening position would be critically important for effective (perfect?) disappearance of speakers: #687

- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage: #520

- Identification of sound reflecting plane/wall by strong excitation of SP unit and room acoustics: #498

- Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000: #495, #497, #503, #507

- The latest Fq-SPL (re-confirmation) of multiple amplifiers SP high-level output signals and that of room air sound at listening position: all measured by “FFT averaging of recorded cumulative DSP-processed flat white noise” (as of June 8, 2025): #1,009

 

[No_hair_left]

Just for your possible reference and interest, my below posts on my project thread will give you some suggestions for improvements, I assume and hope.

- Not only the precision (0.1 msec level) time alignment over all the SP drivers but also SP facing directions and sound-deadening space behind the SPs plus behind our listening position would be critically important for effective (perfect?) disappearance of speakers: #687

- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage: #520

- Identification of sound reflecting plane/wall by strong excitation of SP unit and room acoustics: #498

- Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000: #495, #497, #503, #507

- The latest Fq-SPL (re-confirmation) of multiple amplifiers SP high-level output signals and that of room air sound at listening position: all measured by “FFT averaging of recorded cumulative DSP-processed flat white noise” (as of June 8, 2025): #1,009

I give this a read.

 

[No_hair_left]

Please read the PDF linked in this post about toe-in and how to minimise seat to seat variation. Sometimes the room makes it impossible, but you may be able to improve your situation.

This is what I feared for this, I can't reasonably toe them in but cross-firing would just look ridiculous to me, seems like its only really a solution if you use a acoustic screen to hide the speakers.

 

[Bob from Florida]

I would keep the speakers firing more straight forward to keep a wider soundstage, maybe slightly toeing in. Adding at least 2 subs like the SVS 3000 Micro’s will help to equalize the bass across different listening positions. If you can boost the dips between 1 & 2 KHZ, you might be able to liven things up some. Hard to overcome the room contributions.
The downside of measuring stuff is you become aware of issues that you may not have noticed previously.

 

[No_hair_left]

I would keep the speakers firing more straight forward to keep a wider soundstage, maybe slightly toeing in. Adding at least 2 subs like the SVS 3000 Micro’s will help to equalize the bass across different listening positions. If you can boost the dips between 1 & 2 KHZ, you might be able to liven things up some. Hard to overcome the room contributions.
The downside of measuring stuff is you become aware of issues that you may not have noticed previously.

I wanted to normalise the spl across the 3 seats somewhat as when I had them wall mounted firing straight it was way to one sided depending on the side I or anyone else sat, 10degrees toe in from straight seems best for the 3 seats.