what effects soundstage depth

[kifeinthesink]

Putting aside the recording and room acoustics, What factors in a speaker design determine sound stage depth.

Will certain changes to specific aspects of a design make the sound stage more forward or recessed or is this just a result of everything working correctly together and reproducing whats recorded.

I ask because I have a speaker that seems to suck the life out of vocals and the singer always seems to be recessed in space. The frequency response is flat when measured close up.

That said, I don't really want to trouble shoot this particular speaker. I'm more interested in better understanding speaker imaging.


Thanks


David

[doug20]

Have you measured the off axis response?

Im not an expert but the best sound stage/imaging etc points to having great off-axis response and low harmonic distortion, low linear distortion.

[Helmuth]

By what I know I come to the conclusion:

Good off-axes for wide stereo image.
Good impulse behaviour so everything is very detailed to hear with out any muddy sound.

The placing is the result of the difference in loudness between left and right channel and phase.

Then the reflections of the listen room play also their roll, by interfering the stereo image.


Your speaker and listening room messes with the phase and impulse response and loudness of the original recording.


Regards Helmuth

[Key]

It helps to understand how people mic and mix for depth effects.

Basically as a sound gets closer to you the bass gradually increases (proximity effect) and there is less reverb. As a sound gets further away it has gradually less bass and more reverb.

High end is effected as well but it's kind of tricky. But basically the same idea if there is a lot of high end it will sound close the more you roll it off it will give the illusion of depth.

So if you have a properly setup stereo system (equilateral triangle) and you take a mono signal add some reverb and roll off the bass a bit it should push back in distance wel beyond the wall behind the speakers.

If I was trying to make a playback system that would expose the depth in recordings it would probably have to de-master most CDs with some light filtering. Bring 5kHz down about 3dB with a wide band EQ and maybe bring the bass down a little. THis is just based on odds and the way I have found most CDs being mastered and mixed. It will be different if your system isn't somewhat flat.

But as far as what needs to be there I think a wide dispersion/off axis reponse is very important. Probably second would be phase relationship in the speakers and crossovers.

[kifeinthesink]

Thanks for the replies.

That bit about the recording was interesting.

As I think about it I suspect something else is at play in the recessed voices. I need to make more thorough measurements. Could be related to the transmission lines I built. I'm going to try them in ported cabinets for comparison sake.


D

[planet10]

1st it has to be on the recording...

a number of things in no specific order...

1/ downward dynamic range. The speaker has to have the ability to reproduce -- even in the precense of a much streonger signal, all the subtle peices of information that carry imaging/soundstaging clues. Think 40 dB down. This means everthing must be quiet -- the box, the cone, diffraction, internal reflections.

2/ the harmonics need to stay within the envelope of the fundemental. Good impulse, good phase response.

3/ meantioned already. speaker placement in the room

What are your speakers?

dave

[SY]

Polar pattern, room acoustics. All else is minor, assuming (as Dave points out) that the recording is well-made in that respect.

Midrange humps in the response can move things forward. Dips can move things back.

[Key]

I would actually argue that room acoustics aren't exactly important or as important as people and measurements would lead you to believe. I think as long as you get rid of early reflections and give a decent amount of breathing room for your speakers you can effectively blank out the rooms effect with your mind. Sort of like looking directly into a flashlight - you can not see the reflected light outside of the source because your senses are being flooded by the source itself. I think surround sound is better at this for obvious coverage reasons.

[JLH]

Originally posted by planet10
1st it has to be on the recording...

a number of things in no specific order...

1/ downward dynamic range. The speaker has to have the ability to reproduce -- even in the precense of a much streonger signal, all the subtle peices of information that carry imaging/soundstaging clues. Think 40 dB down. This means everthing must be quiet -- the box, the cone, diffraction, internal reflections.

2/ the harmonics need to stay within the envelope of the fundemental. Good impulse, good phase response.

3/ meantioned already. speaker placement in the room

What are your speakers?

dave

I agree with this, but would point more strongly at phase and downward dynamic range. I believe these are the two most important factors in getting that hair raising imaging effect from a good recording.

[gtforme00]

Originally posted by Key
I would actually argue that room acoustics aren't exactly important or as important as people and measurements would lead you to believe. I think as long as you get rid of early reflections and give a decent amount of breathing room for your speakers you can effectively blank out the rooms effect with your mind. Sort of like looking directly into a flashlight - you can not see the reflected light outside of the source because your senses are being flooded by the source itself. I think surround sound is better at this for obvious coverage reasons.

Getting rid of early reflections and positioning the speakers in adequate space IS the heart of room acoustics!

-David