Soundstage

[timm]

Hi all - I want to see if you can help a bit. I get great focus in between my odysseys... The vocal is dead center / guitar,drums, bass all take their space and are heard either stage left or right. The problem: I don't really get anything wider than where my speakers are positioned. Let me give you the lowdown: They are 7 feet apart (measured from the inside of each cabinet). One speaker is 2.5' away from the right wall - the other has no wall. My seating position is between 9 to 10' away. I have approx. 1/3 of the panel toed in using the flash light trick.

Each speaker is about 5 feet from the front wall.... Any suggestions? I am kind of stuck where they are at - but even so - If any of you have any ideas on how to get the wider soundstage - I would be interested. Thx. Tim

 

[Horchem1972]

The open wall in not helping you at all.Usually less toe in means a larger soundstage,as more toe in is less of a soundstage but a tighter center image.It may be the type of music you listen to.Try a CD by Roger Waters called "Amused to Death".There are sections such as the dog barking that should extend far outside the speakers.Try to remove at least first order reflections.A good trick is to sit in the sweetspot and have someone move a mirror along the wall.Where you see yourself in the mirror in a reflection point.Try to put an absorbative material in that spot.I have also noticed that putting heavy drapes on the walls behind the speakers will help:music: alot.The best components cannot work wonders with horrible acoustics.Good luck.

 

[timm]

Thats interesting. I figured the open wall would be my friend... There is a wall - but it is about 13' away from the left speaker. I figured - less reflections - the better... I wouldn't think there would be any reflections off the wall 13' away. Do you really think an absorbing material on the right wall (2.5' away from speaker) would help improve the width of the soundstage? I'm trying to figure out why....Maybe you or someone has an explanation?

 

[JonFo]

Thats interesting. I figured the open wall would be my friend... There is a wall - but it is about 13' away from the left speaker. I figured - less reflections - the better... I wouldn't think there would be any reflections off the wall 13' away. Do you really think an absorbing material on the right wall (2.5' away from speaker) would help improve the width of the soundstage? I'm trying to figure out why....Maybe you or someone has an explanation?

Bingo, you arrived at the right conclusion, you need to treat the right wall to better balance the soundstage.

The other thing you need to possibly address is the wall behind the speakers. Can you tell us more about what's there? Is it just a plain flat wall?

One thing to try is to put some absorption behind the speakers and see what that does to your imaging.

Cheers,

 

[sleepysurf]

I fully understand the importance of treating the first side reflections for standard cone speakers (with point source dispersion), but am still baffled why folks preach the same for ML's. We know that stat panels have poor lateral (even moreso vertical) dispersion, hence the curvilinear design of ML's stat panels. IMHO, if one (or both) speakers are at least 2-3 ft from the side walls, with a moderate amount of toe-in, I would think the significance of side wall reflections would be minimal. I would think a narrow soundstage is more likely due to a combination of other acoustic issues, such as...
-speaker distance from back wall
-placement of diffusion/absorption behind and/or between speakers
-other reflective surfaces (? furniture, TV, ceiling and room wall geometry)
-location of rear wall behind listening position

Anybody know of an authoritative review of acoustic treatment specifically for electrostatic speakers?

 

[Rich]

We know that stat panels have poor lateral (even moreso vertical) dispersion, hence the curvilinear design of ML's stat panels. IMHO, if one (or both) speakers are at least 2-3 ft from the side walls, with a moderate amount of toe-in, I would think the significance of side wall reflections would be minimal.

It is exactly because of the curvilinear nature of the ML panel that side wall reflections come into play. As you note, it is not as bad as with point source speakers, but it can and does make a difference. The sound wave leaves the speaker in an expanding curve and it will hit the side walls and bounce back to the listener unless the speakers are much further from the side walls than 2 to 3 feet.

Also, the toe-in creates secondary reflections off of the side walls. Remember that when the rear wave bounces off of the the front wall, if the speaker is toed in, it will then reflect towards the side wall and back to the listener. This is why it is important to have some absorption behind your speakers, particularly in a smaller room where you can't pull the speakers out 5' or so from the wall and have them more than 2' to 3' from the side walls.

I would think a narrow soundstage is more likely due to a combination of other acoustic issues, such as...
-speaker distance from back wall
-placement of diffusion/absorption behind and/or between speakers
-other reflective surfaces (? furniture, TV, ceiling and room wall geometry)
-location of rear wall behind listening position

Obviously, all of these issues are important. The thing about acoustics is that everything matters to some degree. Placement of speakers, size and shape of room, reflectivity of surfaces, quality of components, etc. etc. all play a role.

Personally, I have found that using acoustic absorptive panels makes the biggest difference in soundstage and imaging. My speakers are not ideally placed: they are 2' from the side walls and the panels are about 3' from the rear walls. But I have a complete set of acoustic panels in key spots throughout my room and I experience holographic imaging and a soundstage that sometimes extends beyond the walls of the room (not always, but on certain tracks).

Anybody know of an authoritative review of acoustic treatment specifically for electrostatic speakers?

Only JonFo's threads on this forum.

 

[Horchem1972]

Open wall

When one speaker is in front of a wall and the other speakers has no wall it will always sound differant.That would be like putting one speaker five feet in front of a wall and the other against a wall.The back wave and reflections will be completely differant.If they were conventional box speakers it would not be as big of a deal.Dipole speakers have completely differant sonic characteristics.If you have some heavy drapes place them behind your speakers and see if they make a differance.I will guarantee that they will.This is only my opinion,and many:music: others will differ.Good luck in finding the best for your situation.

 

[sleepysurf]

Timm, couldn't find a picture of your setup in the systems section. Why don't you post a picture here and we can give more specific suggestions.

 

[timm]

Timm, couldn't find a picture of your setup in the systems section. Why don't you post a picture here and we can give more specific suggestions.

You are right - I have to get to that... Currently there is a tv there - but I removed it - and still the same basic issue. Removing the tv improved the sound (especially at louder volumes)... But, I can't get away with that right now...

The wall behind the speakers is flat.. but the room is shaped like an L - with the bottom leg of the L being my back wall... The room is about 25' wide - but I can only use about 12' of width because of supports going down the middle of the room (it is the basement). Don't get me wrong - we image very well - things sound balanced - and things sound great IN BETWEEN the speakers... very holographic... But, nothing really beyond the outside of the speakers. I will try the mirror trick - and put some blanket on that wall to see what happens.

By the way - I know it has been said - but this is an awsome forum - and everyone here is appreciated...

 

[timm]

One other note - I have found placing a blanket on the wall in the middle of the speakers seems to make them sound too dull....

 

[benleeys]

One other note - I have found placing a blanket on the wall in the middle of the speakers seems to make them sound too dull....

That has been my experience too, timm. A singer will sound like he's got a stuffy nose! But an appropriated absorbant like a tube trap or a RealTrap penal placed against the wall directly behind each speaker will do wonders to the sound image. Add traps to kill first reflections from side walls, and you're almost there.

I also found that if you like your sound loud, you'd do well also to have some absorbant on your rear wall too, ie if it's a blank wall. Bookshelves are great. Personally, I listen to my music rather on the soft side, so I do not like my room to be too dead.

 

[JonFo]

...
Also, the toe-in creates secondary reflections off of the side walls. Remember that when the rear wave bounces off of the the front wall, if the speaker is toed in, it will then reflect towards the side wall and back to the listener. This is why it is important to have some absorption behind your speakers, particularly in a smaller room where you can't pull the speakers out 5' or so from the wall and have them more than 2' to 3' from the side walls.

...

Rich is absolutly correct, the side wall reflecctions are not so much fromt he front of the speaker as from the REAR. That rear wave bouncing off the front wall, into the side is what can impact imaging (and frequency response) to a huge degree.

Try treating the front wall first with an absorber than goes down to at least 400hz (which means it will be about 3 to 4" thick), then you might also try treating the side wall at the reflection point for the REAR wave bouncing off the front wall.

Also, note that some of the side-wall impacts are not jsut highs, but the mid-bass coming from the woofer, which is a tad less directional than highs.

 

[timm]

Is there anything other than blankets I can use to try and experiment with? Seems like this is something I should be able to 'fiddle' with prior to either a DIY or a purchase.... Let me know if you think a blanket is the best way to go.

Re the sound of the speakers w/blankets in the middle of the speakers --- It doesn't sound stuffy - I would say it just doesn't sound alive.... Although, as I said, moving the tv did bring on an improvement - but it is not something I can do permanently....

 

[Bernard]

Is there anything other than blankets I can use to try and experiment with? Seems like this is something I should be able to 'fiddle' with prior to either a DIY or a purchase....

As a first step try my cheap trick of using swimming pool noodles - check my system description. They cost about a buck apiece.

 

[JohnA]

...
Try treating the front wall first with an absorber than goes down to at least 400hz (which means it will be about 3 to 4" thick),...

After doing this I noted a 2db drop in volume at the listening position. Not surprising, if you think about it: totally absorbing the rear wave would roughly drop it by 3db, wouldn't it)
This had the side-effect of altering the balance between front speakers and surround-speakers/LFE in surround recordings. Easy to fix once identified.

So to recoup, in my case absorbing most of the rear wave increased the soundstage, made everything more accurate and crisp, at the expense of more power. Fair trade I think.:rocker:

 

[timm]

Just a thought here...I thought part of the magic of the ML was its dipole design.. By deadening the front wall - aren't we sort of defeating that? I guess what I am asking is - those of you that have done this - have you gained image - but lost transparency?

 

[timm]

The open wall in not helping you at all.Usually less toe in means a larger soundstage,as more toe in is less of a soundstage but a tighter center image.It may be the type of music you listen to.Try a CD by Roger Waters called "Amused to Death".There are sections such as the dog barking that should extend far outside the speakers.Try to remove at least first order reflections.A good trick is to sit in the sweetspot and have someone move a mirror along the wall.Where you see yourself in the mirror in a reflection point.Try to put an absorbative material in that spot.I have also noticed that putting heavy drapes on the walls behind the speakers will help:music: alot.The best components cannot work wonders with horrible acoustics.Good luck.

Where I see myself in the mirror is a reflection point? Or where I see the speaker is the reflection point? The speaker right?

 

[MOON]

I use these bi fold doors to manage the rear wave behind my Odesseys.I read about it in Sterophile. It cleans up the soundstage and midrange quite a bit. The difference is big in the improvement in sound. The bifold should be at a 30% angle going back to the wall. I have half a bi fold in the corner.With the bi folds in place , the rear wave is dispersed into the room instead of hitting the wall behind the stator and bouncing back into the stator mucking up the sound, and beleive me muck up the sound it does without the bi folds.

In my new room , I will use this setup along with asc corner traps in the rear corners, absorbtion at 1st and 2nd reflection points as well as on the back wall. The diffussers are easy to do, paint them the same color as your walls.The right wall in the 1st picture is one shade deeper in color than the wall behind the stereo, that's why it looks a bit darker in color.

These pictures were taken in my living room. My new room is a dedicated music room, no pictures etc, 2 listening chairs and that's it.

Cheers

 

[JonFo]

Just a thought here...I thought part of the magic of the ML was its dipole design.. By deadening the front wall - aren't we sort of defeating that? I guess what I am asking is - those of you that have done this - have you gained image - but lost transparency?

Timm, the dipole nature is not necessarily a positive from a sound propagation standpoint.

ESL's are dipole because putting the diaphragm over a box would now create all kinds of rear wave reflection issues in the box. And give the resulting colorations of many a box speaker. Also the unequal air pressures between a closed box and the front would not be good either.

So they are open front and back which does deliver that wonderful speed and transparency of ESL's.

The price is, we now have an equal amount of energy radiating out the rear of the speaker.

The 'dipole sound' and associated 'big' soundstage is in some ways like making lemonade from lemons.

By carefully managing the rear-wave, one can indeed increase the perception of width. This comes primarily from the rear wave sound reflected off front then the left and right side walls. Since by placing speakers out the recommended 3 feet or so, the rear wave bounce off the side walls is roughly near or slightly in front of the plane of the speaker, but delayed by 7 to 10ms relative to the front wave launch.

This slight delayed sound arriving from the ‘edges’ of the room is what our brains interpret as a ‘bigger space’ and ‘wider’ soundstage.

So yes, damping the rear wave will indeed have impacts on the soundstage, but it also has equally large impacts on frequency response. As I documented in the room placement and treatments thread, it is highly beneficial to clarity.

So for me, the system has gained more in clarity, smoothness and overall ‘tighness’ than I feel I’ve lost in soundstage width.

Also, I use Meridian’s TriField processing and my highly tuned front channel array to still manage an incredibly wide and cohesive soundstage.

But even in 2ch modes, the soundfield is very large and pleasing, even with a front wall (and adjacent lateral walls) covered in MiniTraps.

 

[timm]

All I've got to say is - this is CRAZY!!! But- I love it!! We have someone putting bifold doors behind their speakers.... I am not making fun - I know - I believe - I understand - because I have seen what little small tweaks and movements can do for these speakers. But, don't you all find it funny when someone who is not really into it comes in and sees your stuff and says 'What the hell is that behind your speakers?'....'What the hell is that on your walls?' It is a secret - and if my wife knew that - say any future ficus trees were NOT for decoration??? I feel like I'm cheating!!!