Centre image question?

Hari Iyer

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My speakers are 4 feet away from the front wall and 3 feet away from side wall. Subwoofer next to right speaker. Previously my phantom center image was behind the speakers at the centre wall. It was dead centre and my speakers use to disappear.
After 2 week of crossover iteration, my centre image though dead centre has moved forward in-line with the speaker and is no longer on the front wall. The speaker disappears.

My question - what is correct? Front wall centre image or center image in-between speakers? Answer sought.
 
There is nothing right or wrong here, it all boils down to once liking. For me the centre image has to come from behind the speaker else I feel it's on the face kind.
Cheers
 
I have the center image behind the speakers. I too thought shouldn't it be in line with speakers?

Then thought logically it should be behind since the singers and orchestra are behind the mic?

In some songs perhaps there are some pieces of orchestra are in front of and to the side of singers and they are heard at the front and towards outer edge. And this with that Little Devil Lii F6 on cardboard OB :)
 
I have always had it from behind the speakers in my setup. Remember seeing a YouTube video from Paul of PSAudio where he explains why it should be from behind the speakers.
 
My speakers are 4 feet away from the front wall and 3 feet away from side wall. Subwoofer next to right speaker. Previously my phantom center image was behind the speakers at the centre wall. It was dead centre and my speakers use to disappear.
After 2 week of crossover iteration, my centre image though dead centre has moved forward in-line with the speaker and is no longer on the front wall. The speaker disappears.

My question - what is correct? Front wall center image or center image in-between speakers? Answer sought.
Spectral content is the only cue that is available for the auditory system to judge distance/depth for the center image.
https://pubmed.ncbi.nlm.nih.gov/1437460/
So, if the depth of the center image has changed, it has to be due to changes in spectral content resulting from changes that you made to your crossover. That said, your question (what is correct) can not be answered without knowing the spectral content of the source material which determines its perceived distance/depth.
 
In my experience,

there are two types of depth, one that is the result of speaker positioning and the other we hear the way the content is recorded/mixed.

Assuming both speakers reasonably phase aligned (this is important), you would get a very good center image. The depth that your percieve in such situation from all stereo sources would be deeper the more the speakers are pulled further in from the rear wall and again not too close to the side walls.
Also, the perception of soundstage including depth will be more accurate when your listening position is equidistant and in the center of the speakers (again depending on room constrains).
Toeing-in the speakers to the listening spot also creates variations, depending on the tweeter's on-axis/off-axis responce.

The second is depending on the mix, there could be an instument recorded with equal enery to both channels so that you hear it bang in the center, but at the same time could be behind or forward to another instrument or say vocals depending on the was it was recorded in the mix.
In such recordings, you can percieve the instrment that is farthest in the mix in the center image to be deeper.

The best way to test different aspects of soundstage is to use recordings specifically made for speaker placement/tuning etc.

HOPE THE FOLLOWING ARE HELPFUL

I will find you there by Michael Ruff
Pictorial depiction of the stage as recorded by the music director


imaging.JPG


Theme from Pink Panther movie by Henri Mancini
Pictorial depiction of the stage as recorded by the music director


pink panther.jpg


Camarillo by Lincoln Mayoga
Pictorial depiction of the stage as recorded by the music director

camarillo.jpg

 
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I have gotten better spatial distribution (voices even seemingly coming from a long distance back while using a tube preamp than with integrated SS amp.
Spectral content is the only cue that is available for the auditory system to judge distance/depth for the center image.
https://pubmed.ncbi.nlm.nih.gov/1437460/
So, if the depth of the center image has changed, it has to be due to changes in spectral content resulting from changes that you made to your crossover. That said, your question (what is correct) can not be answered without knowing the spectral content of the source material which determines its perceived distance/depth.
“The results indicate that a decrease in high-frequency content (as might physically be produced by passage through a greater amount of air) can lead to increases in perceived auditory distance, but only when compared with similar sounds having a somewhat different high-frequency content”

So can we say that systems that can dig lower into the bass can produce the higher perceived relative distance between sounds when it plays content that also has simultaneous contrasting high frequency matter. It was intuitively felt that lower frequencies will sound distant than higher frequencies. But It’s interesting to note that if one is listening to just a bass frequency, it won’t feel distant - the contrast is needed for the brain to perceive the distance.

Coming to the OP’s problem then, assuming he senses the distance has shrunk for the same musical content as he was listening earlier to, can one deduct that probably the recent changes made by him might be cutting off the lower or higher (or both) frequencies more than earlier reducing the effective contrast?
 
I have the center image behind the speakers. I too thought shouldn't it be in line with speakers?

Then thought logically it should be behind since the singers and orchestra are behind the mic?

In some songs perhaps there are some pieces of orchestra are in front of and to the side of singers and they are heard at the front and towards outer edge. And this with that Little Devil Lii F6 on cardboard OB :)
I fail to follow your argument that a virtual center image should be behind the speakers because the orchestra or singer is behind the microphones. Take a recording situation in which a singer is standing five feet behind the plane of and equidistant from two stereo microphones. Now, consider the situation in which the singer is five feet in front of the plane of the two microphones. The electrical signals from the microphones for the two cases are going to be identical. Consequently, based solely on the electrical signals from the microphones there is no way of knowing if the singer is five feet behind or five feet in front of the plane of the two recording microphones.
The above argument assumes that the recording microphones and the singer are omni-directional. If that is not the case, then the determination of whether the singer is in front of or behind the plane of the recording microphones boils down to differences in spectral content, as I have stated previously.
 
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I have the center image behind the speakers. I too thought shouldn't it be in line with speakers?

Then thought logically it should be behind since the singers and orchestra are behind the mic?

In some songs perhaps there are some pieces of orchestra are in front of and to the side of singers and they are heard at the front and towards outer edge. And this with that Little Devil Lii F6 on cardboard OB :)
Shouldn't it be opposite then for the speakers playing the vocalist? If singer's are behind the microphone, then when reproducing the content they should be in-line with the speakers at the centre.
 
My speakers are 4 feet away from the front wall and 3 feet away from side wall. Subwoofer next to right speaker. Previously my phantom center image was behind the speakers at the centre wall. It was dead centre and my speakers use to disappear.
After 2 week of crossover iteration, my centre image though dead centre has moved forward in-line with the speaker and is no longer on the front wall. The speaker disappears.

My question - what is correct? Front wall centre image or center image in-between speakers? Answer sought.
Your are seeing the fruits of a good X-over upgrade. Depth perception in the overall soundstage is what people chase after. Now tell us more about whats “different” post the upgrade.
 
Shouldn't it be opposite then for the speakers playing the vocalist? If singer's are behind the microphone, then when reproducing the content they should be in-line with the speakers at the centre.
So here are a few examples

If you can, hear a good 3 mic recording for example mercury living presence or 2 mic recordings of RCA. The mic is never only placed in front of the performers(120 piece orchestra).
But we still get full depth perception. If the soundstage and then the center image were to begin in line with speakers and in line with the mic placements then you would only get partial depth perception which is not the case. Now this is the same for vocalists and instruments.

If you do get a chance to hear the original recording/vinyl of the Carnegie hall concert by harry belafonte on a well setup system pls hear it. He sings and talks moving around on stage, left to right and back to front.
All your questions will be answered.
 
Your are seeing the fruits of a good X-over upgrade. Depth perception in the overall soundstage is what people chase after. Now tell us more about whats “different” post the upgrade.
2 months ago, I set some design goals for my loudspeakers as doing a piece meal approach was not taking me anywhere both measured results or listening experience wise. The design goals are,
- perfect step response at a mic positionof 50" in-between my midrange and compression driver.
- perfect squarewave and impulse response at the above mic position.
- apply B&K house curve to allow proper spectral decay from low to high frequency.
- a decent group delay
- minimum phase speaker system

After 2+ years of toil and in the past 2 months of design iterations, simulations, measurements and fine tuning could achieve atleast 98% of what I set out to achieve. This itself gave me a sense of fullness and contentment.

Listening wise, I can now sit any location in my room and still get center image focus from that particular sitting position. The entire listening room is a sweet spot now and not the one sitting in-between the speakers. This gives me lots of listening flexibility.
The perfect Square wave response indicates that all frequencies arrive at the same level and the same time at my mic position in time domain. The perfect step response indicates that all drivers are well integrated with each other again in time domain. Though I am not 100% satisfied with the minimum phase, but again that's a fix for some other time. Impulse response anomalies indicate frequency levels, room reflection and boundary conditions. The B&K house curve is an important consideration in achieving spectral decay at high freq especially in small to medium rooms. As I am building this design for my own use, I have the luxury of applying the exact curve for the speakers and for the intended room.
 
My speakers are 4 feet away from the front wall and 3 feet away from side wall. Subwoofer next to right speaker. Previously my phantom center image was behind the speakers at the centre wall. It was dead centre and my speakers use to disappear.
After 2 week of crossover iteration, my centre image though dead centre has moved forward in-line with the speaker and is no longer on the front wall. The speaker disappears.

My question - what is correct? Front wall centre image or center image in-between speakers? Answer sought.
Here is an interesting and comprehensive review article that pertains to stereo and the creation of virtual audio images in space.
 
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