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Toe-in, sounds stage, center image and dialog definition

Nwickliff

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Even though I have the curve I want and the desired amplitude at the desired frequency is it possible I'm getting "smearing" by achieving that amplitude by reflected sound vs direct sound? Could this change the intelligibility of dialogue etc?

Hello everyone. I have a pair of RP600m's with GR research XO and upgrades. Using mini DSP to get the curve I like most. I've noticed when I have zero toe-in I get a wider sound stage (sounds like surround sound). RP600m already has very narrow dispersion. They also have a rise in the HF at around 4K and up. That is completely gone with no toe-in. but...
Center image might have lost just a tiny bit of its strength or perhaps it's like how we hear frequencies in that if you boost a certain frequency it sounds as if you have decreased surrounding frequencies. Everything is relative in this business.

Another added benefit is that when I'm wandering around the room, the extra treble energy in the room means I get all those frequencies when not sitting and listening critically in the listening position.
RP600M-No-Toe-In.jpg
 
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mikewxyz

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A couple comments –
  • Toeing-in your speakers changes the HF response. See attached graph from Sonus Faber for set up recommendations. My speakers/ room response pretty much follow this graph.
  • Smearing is a time domain problem. Look at the Filtered IR tab of REW. If you have 20dB drop before first reflection, there is usually not a smearing problem.
  • If still concerned, listen near field.
  • Buy Floyd E. Toole’s Book “Sound Reproduction”. He explains all of this in detail.
 

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alex-z

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The RP-600M has great directivity, so it takes well to EQ. I hope the crossover "upgrade" didn't negatively impact that.

A single measurement tells you virtually nothing about a speaker. Off-axis response is critical, not just for the speaker itself but how it interacts with the room. Using the moving mic method before applying any EQ.

Also, you should measure at a higher SPL, more separation from the noise floor of the room gives you more accurate data.
 
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Nwickliff

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The RP-600M has great directivity, so it takes well to EQ. I hope the crossover "upgrade" didn't negatively impact that.

A single measurement tells you virtually nothing about a speaker. Off-axis response is critical, not just for the speaker itself but how it interacts with the room. Using the moving mic method before applying any EQ.

Also, you should measure at a higher SPL, more separation from the noise floor of the room gives you more accurate data.

It was moving mic measurement and that is why the SPL is so low. Trust me, no noise floor getting into that measurement. Random Pink Noise I think. The speaker has similar off-axis and on-axis responses. HF just drops off, which is what I used to "mechanically" eq the tilting up HF. XO response is not going to change the directivity accept for vertical. That's speaker size, waveguide, and box design. At any rate the XO fixes the cancelation in the OEM design.

A couple comments –
  • Toeing-in your speakers changes the HF response. See attached graph from Sonus Faber for set up recommendations. My speakers/ room response pretty much follow this graph.
  • Smearing is a time domain problem. Look at the Filtered IR tab of REW. If you have 20dB drop before first reflection, there is usually not a smearing problem.
  • If still concerned, listen near field.
  • Buy Floyd E. Toole’s Book “Sound Reproduction”. He explains all of this in detail.

That's precisely why I decided to try without the toe-in. With toe-in for on axis listening, the HF was tilted up 10db from the lowest point in the XO at 1.4k or thereabouts! Even after XO upgrade there was still a 5db tilt or so when listening on-axis. before I just eq'd that out but with narrow dispersion of these speakers the magic was happening only in between the speakers when toed in. When pointed straight out I get back to that nice Harmon curve as shown in my measurement above without eq and the magic now how happens well outside the speakers with still a strong center image.

When not toeing out I have to believe that I am getting much more percentage of early reflection contributing to the direct sound vs toed to listening position and that is why I ask about smearing as that would absolutely have to do with timing.
 

chips666

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Hi,
Try time intensity trading
works well for me ...
;)
 

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FeddyLost

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When not toeing out I have to believe that I am getting much more percentage of early reflection contributing to the direct sound vs toed to listening position and that is why I ask about smearing as that would absolutely have to do with timing
You have a lot of options
1) if you have minidsp anyway, you can toe-in and lower HF with equalisation
2) if you need wider scene, you can stand speakers straight and use HF absorption in places of first reflections - thick foam panels will be enough
3) any combination of 1 and 2 ...
 
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Nwickliff

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Hi,
Try time intensity trading
works well for me ...
;)
That's what I used to do and liked it very much. With such narrow dispersion speakers, the sound was contained between the speakers, however. No side wall reflections so no soundstage width.

That graph looks like a subwoofer measurement plus room noise, no main speakers. 20dB boost below 80Hz?
I like to go boom! lol. Seriously though, I listen at fairly low volumes a lot of the time and this gives a much fuller sound at these volumes. When I watch movies I like the boom, oh, who am I kidding I like the boom when I listen to music too.
It's only about 10db boost from 80hz not 20db.

You have a lot of options
1) if you have minidsp anyway, you can toe-in and lower HF with equalisation
2) if you need wider scene, you can stand speakers straight and use HF absorption in places of first reflections - thick foam panels will be enough
3) any combination of 1 and 2 ...
1 is my usual go-to. Enjoying number two without panels but if I add those panels I will lose both soundstage width and HF energy which will result in a lower than desired slope no?
 

FeddyLost

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but if I add those panels I will lose both soundstage width and HF energy which will result in a lower than desired slope no?
I don't think that you'll lose a lot of soundstage width if you will treat only first reflections with thin absorption effective from 1,5-2K. It will remove some excessive HF, but midrange will still be there.
And you still have 5 Db+ of HF energy on-axis. I'd not bother about that it standard room.
Also, there are some abfussors/diffsorbers from GIK, for example. It's slotted/perforated panel on foam, which absorbs and scatters simultaneously. Looks nice, works well if we don't need to tame LF.
 
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Nwickliff

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I don't think that you'll lose a lot of soundstage width if you will treat only first reflections with thin absorption effective from 1,5-2K. It will remove some excessive HF, but midrange will still be there.
And you still have 5 Db+ of HF energy on-axis. I'd not bother about that it standard room.
Also, there are some abfussors/diffsorbers from GIK, for example. It's slotted/perforated panel on foam, which absorbs and scatters simultaneously. Looks nice, works well if we don't need to tame LF.
Thank you. I have also noticed with less toe in the sound doesn't seem to be coming from the speakers so obviously and I like that a lot. Toed in gives crazy strong image but since it doesn't get wider than speakers any wider imaging sounds are obviously coming from the speakers.
 

Geoffkait

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Just a quick comment, speakers in general should be a lot closer together than most people probably realize. The best way to proceed, all things being equal, is to start with speakers four feet apart, then slowly move them farther apart until the soundstage snaps together. It’s a mistake to think that speakers must be wide apart to get a wide soundstage. There are obviously many factors involved in getting a soundstage to snap, crackle and pop.
 
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Nwickliff

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Just a quick comment, speakers in general should be a lot closer together than most people probably realize. The best way to proceed, all things being equal, is to start with speakers four feet apart, then slowly move them farther apart until the soundstage snaps together. It’s a mistake to think that speakers must be wide apart to get a wide soundstage. There are obviously many factors involved in getting a soundstage to snap, crackle and pop.
Problem is the room is the most important variable in any equation dealing with speakers. That is literally the thing that is almost never equal. When you say most are too wide, how wide too wide? Where are you getting this data from? I would argue that most aren’t wide enough. My data is somewhat anecdotal but comes from the hundreds of photos I see where speakers are on either side of there television(too close IMO. Doesn’t the equilateral triangle matter more than just speaker width?
 

Geoffkait

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I posted yesterday somewhere on this forum the best way to determine absolute speaker locations in any room for any speakers is to use the the speaker set-up track on XLO Test CD or similar test CD, which is self explanatory.

Trying to find the ideal speaker locations by the old ”move a little, listen a little” technique is ineffective in finding the ideal locations. You need a way to measure your progress. Otherwise, trying to find the *absolute best* locations is like trying to solve x simultaneous equations in x + n unknowns.

My experience is the distance between speakers when in their ideal positions is shorter than most people would anticipate. Most people probably believe speakers should be far apart to get a wide soundstage and that the speakers should be toed in for the same reason. But I’m saying those beliefs are mistaken.

Geoff Kait
Machina Dynamica
Not too chicken to change
 
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Nwickliff

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I posted yesterday somewhere on this forum the best way to determine absolute speaker locations in any room for any speakers is to use the the speaker set-up track on XLO Test CD or similar test CD, which is self explanatory.

Trying to find the ideal speaker locations by the old ”move a little, listen a little” technique is ineffective in finding the ideal locations. You need a way to measure your progress. Otherwise, trying to find the *absolute best* locations is like trying to solve x simultaneous equations in x + n unknowns.

My experience is the distance between speakers when in their ideal positions is shorter than most people would anticipate. Most people probably believe speakers should be far apart to get a wide soundstage and that the speakers should be toed in for the same reason. But I’m saying those beliefs are mistaken.

Geoff Kait
Machina Dynamica
Not too chicken to change


I understand where you are coming from and think I mostly agree. My concerns are you say the solution is
use the the speaker set-up track on XLO Test CD
which I assume entails
move a little, listen a little
. So I think, perhaps your'e saying your main qualm is with what people use as their source material to do their critical listening.

My other question, which I asked but I never received a response about was, the use of the equilateral triangle, which has been documented by many authorities as the correct way to set up your speakers.

Lastly, where are you getting your data that
the distance between speakers when in their ideal positions is shorter than most people would anticipate.
I stated I sensed the opposite is shown by hundreds if not thousands of photos I've seen with speakers set up just outside the television (4ft apart) at best with listening positions a good 9 -15ft from the television.

Thank you for reminding me. I am very interested in getting one of these setup cd's. I wish I could find something similar to purchase on iTunes for streaming and ease of use.
 

Geoffkait

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The reason I say use the XLO or similar out-of-phase track to set speakers up is that when the sound is coming at you from all around you then that’s the absolute best speaker locations. But you’re right it does involve moving a little, listening a little. The difference is that when audiophiles use a recording to try and find the absolute best speaker locations, source material as you say, they don’t actually know a priori what the best sound possible in their room is for that source material, so they’re only guessing they found the magic spot for BOTH speakers. But don’t think that it’s easy even with the CD out of phase track. Without at least addressing room acoustics to some degree it will not be possible to obtain the case with the CD track where the sound of the voice on the track is 100% diffuse.

I imagine some good results can be obtained using equilateral triangle technique, live end/dead end technique, laser pointers, etc. but the out of phase track allows for the absolute best speaker locations independent of type of speaker or room. But you can always do better, this is not supposed to be an overnight operation.

I realize others do things differently, but the whole procedure of treating the room and using the out-of-phase track eliminates a lot of variables that cannot be controlled by logic or trial and error. Vibration isolation, vibration control, control of room acoustics anomalies. Where does it all end?

I think I said yesterday but in case I didn’t, my experience is that speakers should be closer together rather than farther apart came from the recommendation contained in the XLO Test CD pamphlet from the guys who produced the XLO Test CD - Roger Skoff and Prof Keith Johnson.

I presume there are other similar CDs or LPS, ETC.
 
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Nwickliff

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The reason I say use the XLO or similar out-of-phase track to set speakers up is that when the sound is coming at you from all around you then that’s the absolute best speaker locations. But you’re right it does involve moving a little, listening a little. The difference is that when audiophiles use a recording to try and find the absolute best speaker locations, source material as you say, they don’t actually know a priori what the best sound possible in their room is for that source material, so they’re only guessing they found the magic spot for BOTH speakers. But don’t think that it’s easy even with the CD out of phase track. Without at least addressing room acoustics to some degree it will not be possible to obtain the case with the CD track where the sound of the voice on the track is 100% diffuse.

I imagine some good results can be obtained using equilateral triangle technique, live end/dead end technique, laser pointers, etc. but the out of phase track allows for the absolute best speaker locations independent of type of speaker or room. But you can always do better, this is not supposed to be an overnight operation.

I realize others do things differently, but the whole procedure of treating the room and using the out-of-phase track eliminates a lot of variables that cannot be controlled by logic or trial and error. Vibration isolation, vibration control, control of room acoustics anomalies. Where does it all end?

I think I said yesterday but in case I didn’t, my experience is that speakers should be closer together rather than farther apart came from the recommendation contained in the XLO Test CD pamphlet from the guys who produced the XLO Test CD - Roger Skoff and Prof Keith Johnson.
Thanks for your response. Unfortunately, I'm not able to move my speakers any closer together than they are currently but, perhaps I'll try this in my office sometime. I've been playing with timing, positioning, and eq for the better part of a year now and I'm very satisfied with the compromise I have struck with speakers a couple of feet from the wall and on either side of a mantle as to not look out of place in an ordinary living room setup. They are quite wide apart.

Now if only there could be an auto dolly system where you could set the speakers on a stand with remote controlled wheels so you could slowly manipulate the position without moving from the listening position...that, my friend, would be sublime!
 

Pegwill

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Hi Guys
I have yet to try this, some of you may have heard it before it’s called the ‘Waterloo’ effect after the Kinks famous hit ‘Waterloo Sunset’
You can read about here

I still haven’t got around to try this yet, not fit enough to move my speakers around, but thought it might be worth a mention

https://forums.stevehoffman.tv/thre...-improve-your-stereo-playback-with-it.320990/

I still haven’t got around to try this yet, not fit enough to move my speakers around, but I thought it might be worth a mention. I have listen to the track via headphones and it’s quite something, I guess it helps if you like the song in the first place.

Regards
 

Geoffkait

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That sounds like the same thing, more or less, as the out of phase track On XLO Test CD. I.e., the more *diffuse* the sound is when the system is “out of phase” the more focused and holographic the soundstage is when “in phase.“ Now that I think of it you can make your system be out-of-phase (polarity) by switching - and + cables on both speakers. Assuming your system isn’t out of phase already. Heh
 
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