At what point did you stop REW measuring and buy treatments?

[FargateOne]

a much more sensitive test than music for many things like setting speaker toe in, fine tuning the listening position, fine tuning EQ, setting octave to octave balance (voicing), listening for resonances, and other uses.
Just move you head left and right and then front and back slightly. With some practice the sound will just snap into focus. That is the right spot.

Maybe it is difficult for you to follow 2 discussions in the same thread, you will say. I tried Pink noise full band at MLP and the sound was spot in the center in front of me. I switched polarity of left front. It was more difficult to find what you described as "were the noise sounds smooth AND the image just locks to a hole in the center" . Yes the sound goes from outside the fronts placement (sorry for my english) but I heared mid and high FR in the middle of my head or in front of me. Moving the head a little changed the SS&I. I play with the toe until the sound was spread evenly toward the room. I guess it wasn't what you meant. When I reverse the leads am I searching to recreate by toeing in the speakers the spot dead center I had befor doing so?

 

[hilde45]

I suspect that user error keeps creeping into my measurement labelling or...I don't know what else. I wonder if there is an issue with my sub causing some problems. Hmmm.

Anyway, I will do these new scans and carefully label them. I'll do each scan twice, too before changing the settings.

I've copied out your instructions and will print and execute later this morning. (You know, when my family is awake!)

p.s. Not sure where you meant the best place for gear would be -- along the side (got that) but in FRONT of the 1st side reflection point (closer to the front wall, i.e., the wall I look at while listening) or BEHIND the 1st reflection point (closer to the rear wall).

Linearphase, here are the new scans with the name: "FEB 11 linearaudio.mdat"

 

[linearphase]

I suspect that user error keeps creeping into my measurement labelling or...I don't know what else. I wonder if there is an issue with my sub causing some problems. Hmmm.

Anyway, I will do these new scans and carefully label them. I'll do each scan twice, too before changing the settings.

This is a VERY common problem!

I've copied out your instructions and will print and execute later this morning. (You know, when my family is awake!)

p.s. Not sure where you meant the best place for gear would be -- along the side (got that) but in FRONT of the 1st side reflection point (closer to the front wall, i.e., the wall I look at while listening) or BEHIND the 1st reflection point (closer to the rear wall).

No, I meant against the front wall. Not acoustically the best because metal is strong refector of all frequencies. However, conventional speakers do not radiate much high frequency energy behind them. The wider the baffle the lower the frequency that this transition occurs. So getting the gear back some helps, but does not cure the problem. These effects are easily seen in a corrected impulse response. Once you remove the reflections and hear what the sound is like you are not likely to want to go back.
Most audiophiles present their gear front and center, justifiably proud of what they have. The absolute best position is out of the room or in a ventilated closet but few do that.

 

[linearphase]

Maybe it is difficult for you to follow 2 discussions in the same thread, you will say. I tried Pink noise full band at MLP and the sound was spot in the center in front of me. I switched polarity of left front. It was more difficult to find what you described as "were the noise sounds smooth AND the image just locks to a hole in the center" . Yes the sound goes from outside the fronts placement (sorry for my english) but I heared mid and high FR in the middle of my head or in front of me. Moving the head a little changed the SS&I. I play with the toe until the sound was spread evenly toward the room. I guess it wasn't what you meant. When I reverse the leads am I searching to recreate by toeing in the speakers the spot dead center I had befor doing so?

You are close, you just need more practice. Also this is a VERY sensitive test. moving your head a few inches can change the results. What you are listening for is as much of a null in the sound between the two speaker as possible. It may not be totally silent. Is there anything between the speakers, even near the front wall, that is a good sound reflector? If so cover it with a thick quilt or something similar. It is very hard to describe the correct sound. If I am there it is easy. When you get it right there will be very little sound in the middle. The speakers must be symmetrical, the same distance from each side wall, and each speaker the same distance from the corresponding ear.
Once You find the point of as little sound fomenting from the middle with REVERSED polarity reversed, then simply restore polarity to normal.

 

[linearphase]

Congratulations!
Much better, trace 5 and 6 look the same and are pretty good.

(spk72"Left only;sub180 Feb 11)

The way to tell is look at the 0 degree traces, set 1/48 octave smoothing, look for a deep dip at 55Hz meaning the sub and main are out of phase (the wrong phase)
so just set the phase switch to 180 and LISTEN! You might prefer the sub level a little higher say 9:30 or 10! Most guys like their bass level below 100Hz to be 3-4dB about the midband average.

Boosting the bass by adjusting sub level is not the best way to do it but it works OK then way we are set up.

You might hear a little thinness in the mid bass probably noticeable in chesty male voices. This is what we might be able to improve with targeted acoustic treatment.

Look at those good traces with psychoacoustic smoothing, that is much closer to what you actually will hear.

That is about as good as we can do until you get DSP and crossovers and /or room treatment.

 

[linearphase]

The above graph represents improvements in both and extension of low frequency response as well as improved overall smoothness. Even more impressive is the improvement in time domain which is called the energy time curve. These two repose are intimately related mathematically but in a non intuitive way to most people.
This tells us when the energy is arriving from the speaker. The time the energy takes to travel to the mic from the speaker is subtracted so an ideal response should be single large spike at time 0.

Anything else represents a time domain distortion of the speaker and its acoustic environment. The acoustic environment is the dominant distortion.
Listening experience has taught me any refections over 10% in the first 7mS are harmful to perceived sound clarity and imaging. These are not heard as individual reflections but rather the ear/brain fuses them into a single event.

Small refections we call "hair" on the bottom of the graph after 7mS are not necessarily horrible and may add a sense of acoustic spaciousness. However, if a refection is the 7-15mS range occur that are not spectrally similar the brain can perceive them as bad spacial cues and will attempt to discredit your perception of the original acoustic "venue" and says heh, this is a speaker. Lots has been written about this by people FAR smarter than me so let me know if you want more detail. This is why we don't want to alter the spectral balance if we are forced to use first reflection point absorbers. BTW we don't appear to have a big problem now with the way we are currently setup.
The graph below shows were we started and where we are now. Notably these were achieved only by lowering and aiming the speaker, removing reflective objects, slight tweaking of sub and main positions and of course 1st pass sub integration. This is a great start. Brown is where we started, blue is where we are now.

 

[FargateOne]

You are close, you just need more practice. Also this is a VERY sensitive test. moving your head a few inches can change the results. What you are listening for is as much of a null in the sound between the two speaker as possible. It may not be totally silent. Is there anything between the speakers, even near the front wall, that is a good sound reflector? If so cover it with a thick quilt or something similar. It is very hard to describe the correct sound. If I am there it is easy. When you get it right there will be very little sound in the middle. The speakers must be symmetrical, the same distance from each side wall, and each speaker the same distance from the corresponding ear.
Once You find the point of as little sound fomenting from the middle with REVERSED polarity reversed, then simply restore polarity to normal.

Thank you very much. Indeed I have the tv panel and to rack for my gears, avr, amp and dvdplayer, I know it is not good . I will cover them and report.! Your suggestion to use the pink noise signal is very good, really much easier than to listen music or vocals!

 

[Ton]

I used the REW measurements to compose ROON DPS filters and never looked back. Happy as a clam

 

[FargateOne]

@linearphase I said that i would report...a little late but betteer now than never! I put a thick quilt on the tv panel it makes things easier.

I'm still having a little trouble verifying what I need to determine by hearing the pink noise with the polarity reversed on the left speaker. Should the hole in the center be as wide as possible or as focused as possible? Opening the angle of the speakers (less toe-in) sometimes seems to enlarge the "hole" in the center. Is this the way to go?

 

[linearphase]

@linearphase I said that i would report...a little late but betteer now than never! I put a thick quilt on the tv panel it makes things easier.

I'm still having a little trouble verifying what I need to determine by hearing the pink noise with the polarity reversed on the left speaker. Should the hole in the center be as wide as possible or as focused as possible? Opening the angle of the speakers (less toe-in) sometimes seems to enlarge the "hole" in the center. Is this the way to go?

When the speakers are OUT IF PHASE the hole should be as “clearly defined” as possible. Because of the room and room treatment characteristics correct is hard to clearly define. This is a sensitive relative measurement. Maybe only 50% of the people can hear what is BEST, though most can hear different.
Try one more time, moving your head to the left and right 6” from the exact center. You will hear the difference. Once you can hear the “best” with your existing setup you can make slight changes in toe in, speaker distance to other surfaces and listening position to optimize.
Toeing the speakers out usually widens the image and the sweet spot but when get to the critical point the image wil beome unstable. What I mean is the image wil jump to the righ speaker when you move your head right. This means you have gone to far. if the speakers are toed in the image will appear to be strongly centered and not very wide. The best setting is a matter off preference.

 

[FargateOne]

@linearphase
I started with the speakers pointing directly at the listening position and gradually opened them in 10cm steps at a time. My previous arrangement placed the "ideal" angle at 25 cm on each side of the MLP. But I still heard sound in the center (around the syllable sounds she, sea, feese etc). I continued to open the toeing. Until I pointed the speakers at 55cm on each side of the MLP: the center is almost silent, almost without issshh and moving the head a little on each side does not change anything. After reconnecting the left speaker correctly and listening to male or female singers, their apparent voice has moved back while remaining well defined in the center. The rest of the band is wider. I continued to widen the toeing but it seemed less good.
However, I didn't notice if the sound was moving towards the speaker on the side where I moved my head.
I'll go back to testing to verify this.
One thing for sure, your suggestion is the best advice I've ever had on the subject!

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[linearphase]

@linearphase
I started with the speakers pointing directly at the listening position and gradually opened them in 10cm steps at a time. My previous arrangement placed the "ideal" angle at 25 cm on each side of the MLP. But I still heard sound in the center (around the syllable sounds she, sea, feese etc). I continued to open the toeing. Until I pointed the speakers at 55cm on each side of the MLP: the center is almost silent, almost without issshh and moving the head a little on each side does not change anything. After reconnecting the left speaker correctly and listening to male or female singers, their apparent voice has moved back while remaining well defined in the center. The rest of the band is wider. I continued to widen the toeing but it seemed less good.
However, I didn't notice if the sound was moving towards the speaker on the side where I moved my head.
I'll go back to testing to verify this.
One thing for sure, your suggestion is the best advice I've ever had on the subject!

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That is very kind.
Every speaker / room/ placement combination will produce different results and require different settings. When you say you are pointing the speaker 55cm outside of the MLP do you mean that a line that passes through the center of the tweeter is pointing that far outside the center of the head? If so that may be right but seems a little far out. However, that is the whole point of this exercise. Whatever produces a sound stage that is the most realistic to you on the majority of recordings. It is best to use recordings that are made with the simplest possible microphone arrangement and those that are acoustic in nature. Studio recordings have the image generated in the mastering engineers head and vary a great deal.

You can try the signals and suggestions here I like #2.

Phantom Image

 

[FargateOne]

[/QUOTE]

When you say you are pointing the speaker 55cm outside of the MLP do you mean that a line that passes through the center of the tweeter is pointing that far outside the center of the head? If so that may be right but seems a little far out.

Exactly. The photos could help.
The MLP is at 251cm of straight line connecting the 2 front speakers (the base of the triangle if you prefer). Each speaker is 255cm from the MLP (the sides of the triangle). I aim with a laser aligned on the center of the tweeter towards the mlp and I open the angle little by little. I aim at 55cm on each side of the mlp. My Euclidean geometry lessons are too far back to remember how to calculate the angle!

To my surprise, the graph shows no significant difference between a toeing at 0, 25cm or 55cm in the mid-high range. (When my system was in a room in the basement of our house, it was a different story. The mid-high frequency response dropped drastically for a variation of only 20cm of toeing.)

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[FargateOne]

If so that may be right but seems a little far out.

You have sown in me the doubt which makes mad! I went back to the exercise and tightened the angle to 37.5cm on each side of the MLP. My best result overall. Well defined PN signal image in the center in standard polarity and a well defined and stable hole (when I move my head from left to right and forward backword) in reversed polarity. With the music, the singer's voice well defined and the orchestra distributed in a wide SS&I.

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[linearphase]

You have sown in me the doubt which makes mad! I went back to the exercise and tightened the angle to 37.5cm on each side of the MLP. My best result overall. Well defined PN signal image in the center in standard polarity and a well defined and stable hole (when I move my head from left to right and front to back) in reversed polarity. With the music, the singer's voice well defined and the orchestra distributed in a wide SS&I.

Translated with www.DeepL.com/Translator (free version)

Very nice room! Sounds like you have arrived at a good solution, congratulations!