Soundstage- What creates it? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th March 2004, 12:53 PM   #1
Sherman is offline Sherman  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Chicago area
Default Soundstage- What creates it?

I recently built a new set of speakers (stereo, not surround) and I've noticed that on some recordings the soundstage is noticeably wider than the speaker placement. What I mean is while listening with my eyes closed if I point to where an instrument appears to be that point may be substantially farther to the left or right than the speakers.

Also there is more depth than before, though this is easier for me to understand in terms of creating that on a recording.

Some recordings have a wider/deeper stage than others so obviously the way the music is recorded controls this to a great extent.

So can someone explain how the soundstage can appear wider than speaker placement? Or maybe point me to a website that explains it in layman's terms?
  Reply With Quote
Old 19th March 2004, 01:26 PM   #2
Mudge is offline Mudge  United Kingdom
diyAudio Member
 
Join Date: Mar 2004
Location: Nr London
It's a good question, and no-one knows all the answers.
Panning across the soundstage can be accomplished in one of two ways, panning by level and panning by phase error.
Most studio recordings are panned by level (aka Pan-pot-mono) which will normally confine the soundstage to inside the speakers separation.
Natural sound has a phase error (a delay time) between your left and right ear, as well as level differences, which means that sounds can come from beyond the width of the speakers, and if the phase error approaches 180', sounds appear to come from all around at once.
Depth is usually perceived by the spectral imbalance of the direct path sound. Height appears to be determined by the bass content of the first reflected path sound, but AFAIK no-one has conclusively determined this or any other mechanism for judging height in a recording.
__________________
Mark
The king of all that is evil has left the building
  Reply With Quote
Old 19th March 2004, 02:04 PM   #3
jomor is offline jomor  Greece
diyAudio Member
 
jomor's Avatar
 
Join Date: Feb 2004
Location: Athens
The sound engineer who does the recording at the studio, makes recording of each instrument and vocals initially at a seperate channel. Then he combines in a special way those channels, to produce the final 2 channel (stereo) recording.

Lets say that the singer is located exactly in the middle. His/her voice will be recorded to the final stereo recording with the same level (left and right speaker will produce exactly the same spl)
and with no phase delay (at the same time)

Lets say the sound engineer decides to (audibly) put (for example) the violin in a specific spot of the soundstage, left of the singer, and 1 meter deeper (1meter biggest distance from the listener)
He will transfer the initial violin recording, to the final stereo recording by adjusting the balance potentiometer of the violin channel more to the left (making our left speaker playing the violin more loud than the right one,
while the singer will be played at the same level left and right). He will also adjust the left delay potentiometer in a value that corresponds in milliseconds to the 1 meter of longer distance of the volin, compared to the singer (so the left speaker will reproduce the violin some milliseconds later than the right speaker wich is in phase with the centered vocals)
By this way, the sound engineer places each instrument at the desired locations.

This is the simplified technique, but there are more parameters that the sound engineer takes advantage of. Room reflections, echos, can be entered to give a larger room perspective. So in the recording among with the instruments and vocals info, there is room info that can be entered to give the impression of the supposed room that the band is playing.

This is done, while the sound engineer has in mind that we will put our two speakers in a proper position, in front of us (like a band always is) and in a symmetric position. Thats why the speaker placement is critical. The listener's distance from the left and right speaker should be equal and the cables' polarities should be correct (so the time delay trick works well) and the way we put the speakers in our room, decides the way the soundstage will appear to us (keeping the speakers 1 meter from the walls will give a larger and deeper soundstage - due to the wall's reflections, than keeping the speakers 20cm from the walls). There are some basic rules on speaker positioning, but on each room the best result can only be achieved with many hours of experimenting and listening.
  Reply With Quote
Old 19th March 2004, 02:40 PM   #4
diyAudio Member
 
5th element's Avatar
 
Join Date: Oct 2002
Location: England
I have also noticed that the songs where I get the most lateral spread are from tracks with odd sound effects or weird phaseyness added to synthesisers. Normal recordings dont usually extend pass the boudaries of the loudspeakers but some, these electronic ones do.

Unfortunately its probably only a select number of sound engineers who will actually engineer in phase difference between the two channels to create a more realistic sound stage. Also normally when stereo mixes are produced most of the time I think they use total pan, ie sound either from both speakers or the left or the right. Obviously there are some inbetweens, but just panning is not suffucient to create realistic sound stages.

I always doubt hifi reviewers who say their speakers create a soundstage that extends several feet backwards and sidewards from the speakers. David Allcock seems to be one who regularly states this, the soundstage extends into my garden and into the next rooms! This is fabulous for dave if this is how he percieves the sounds, as out brains also have as much to do with creating a sound stage as the sound system does. But I bet if I were to sit exactly where he is in the room with exactly the same material I wouldnt hear what he hears.

I find it very difficult to hear stage depth. This is not music depth. I cane easily hear from one piece of music to the next a difference in stage depth. Ie one piece plays behind the speakers plane, whereas another plays infront. I just find it hard to hear depth between individual intruments, within the stage.

I know what I should do for my career, instead of trying to be a loudspeaker designer, be a recording engineer with a difference I use PHASE MWHAHAHAHAH eat that sony!
__________________
What the hell are you screamin' for? Every five minutes there's a bomb or somethin'! I'm leavin! bzzzz!
  Reply With Quote
Old 19th March 2004, 11:36 PM   #5
Sherman is offline Sherman  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Chicago area
Well, I can't claim the soundstage goes into the next room! It does however extend about 18 inches wider than the speakers. Again it isn't that wide on all recordings but on a couple of recordings it is very noticeable. Neither has weird synth stuff but neither is a live recording either.

As for depth, it doesn't seem to extend behind the speakers but comes out in front. It isn't huge but it isn't that flat wall of sound I'm used to. I actually made recordings with depth while in college and I made recordings where I placed instruments where I wanted left to right but I was never able to extend them beyond the speakers, but then again I never thought of trying!

Sherman
  Reply With Quote
Old 20th March 2004, 02:10 AM   #6
7V is offline 7V  United Kingdom
diyAudio Member
 
7V's Avatar
 
Join Date: Feb 2003
Location: North London
Just a few points based on my experiences with this issue.

Firstly, I believe that phase problems introduced by crossover units interfere with an accurate soundstage and accurate imaging. Vibrations from the speaker enclosure are also a dead giveaway.

However, reflections from walls, floor and ceiling can also completely distort the soundstage picture. These can be minimized with placement and toe-in but they are related to the dispersion characteristics of the drivers used. Another negative for crossovers is that the dispersion characteristics change as you move from woofer to tweeter and this messes up the soundstage.

The point about the sound seeming to come from beyond the speakers is a different, though interesting, issue. Headphones always give a soundstage that goes way beyond the 'speakers'. I'd bet that if you position your speakers so that they're 18" apart, toed in and 6" in front of your head, your soundstage would be way beyond the speakers too.
  Reply With Quote
Old 20th March 2004, 02:26 AM   #7
Mudge is offline Mudge  United Kingdom
diyAudio Member
 
Join Date: Mar 2004
Location: Nr London
Quote:
Originally posted by 7V

The point about the sound seeming to come from beyond the speakers is a different, though interesting, issue. Headphones always give a soundstage that goes way beyond the 'speakers'. I'd bet that if you position your speakers so that they're 18" apart, toed in and 6" in front of your head, your soundstage would be way beyond the speakers too.
I've tried that, not with particularly great speakers, but they imaged consistently enough. The headphone effect has a lot to do with almost no sound from the right channel reaching the left ear and vice versa.
You also loose most of the pinna effects, the head transfer function(s - being complex it is easier to calculate as several paths rather than one composite path) and the room interaction.

Not that I would forsake speakers for headphones unless forced to.
__________________
Mark
The king of all that is evil has left the building
  Reply With Quote
Old 20th March 2004, 09:44 AM   #8
7V is offline 7V  United Kingdom
diyAudio Member
 
7V's Avatar
 
Join Date: Feb 2003
Location: North London
Quote:
Originally posted by Mudge
The headphone effect has a lot to do with almost no sound from the right channel reaching the left ear and vice versa.
Good point. I guess you'd have to increase the distance the speakers were apart and in front for the experiment to be valid.

My thought was that if you can't 'hear' the speaker cabinets (vibrations or resonances), why should the sound not seem to come from beyond the speakers?
  Reply With Quote
Old 20th March 2004, 10:21 AM   #9
Mudge is offline Mudge  United Kingdom
diyAudio Member
 
Join Date: Mar 2004
Location: Nr London
Steve,
If there's no intrinsic phase difference between signal L and signal R, then the soundstage through speakers will depend on the differing arrival times at each ear of each signal and the difference in level. In effect the brain can only calculate soundstage width from the sound being entirely in one speaker or entirely in the other, any condition in between is possible, but nothing beyond that.

When you switch to headphones, there's no difference in arrival time, because the sound doesn't reach your other ear in any comparable signal strength. That part of the auditory complex switches off and level and spectral balance play an increased part in determining soundstage width. Hence why I prefer speakers to headphones, music really needs to be mixed with headphones in mind to sound right through them.

EDIT: I should add that the 'depth' of a sound in one ear only is the determining factor for soundstage width in headphones.
__________________
Mark
The king of all that is evil has left the building
  Reply With Quote
Old 20th March 2004, 10:51 AM   #10
diyAudio Member
 
Circlotron's Avatar
 
Join Date: Jun 2002
Location: Melbourne, Australia
A week or so ago I was listening to a CD of The Shadows, the track was "This 'ol House" IIRC. Right at the very beginning before the music starts you can hear distant voice going "a-one, a-two, a-one-two-three" to get the band starting in time. From where I sit the speakers are at 10:45 and 1:15 o'clock position. On my system this voice appears right over to the left at about the 9:30 position! I played it again and again to just make sure I wasn't imagining it.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What company consistantly creates the highest quality CD recordings you have found? MagneMan Music 3 11th January 2008 08:25 AM
What creates the impedance peaks in ported cabinet? teemuk Multi-Way 1 26th February 2007 09:01 PM
Help me with set up issue - soundstage sqlkev Multi-Way 19 27th July 2006 07:04 PM
Why BJTs creates more stable bias circuits venusgarg Chip Amps 0 7th April 2004 02:44 AM


New To Site? Need Help?

All times are GMT. The time now is 12:35 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2