Do you guys subscribe to Cardas math for speaker distance from front wall?

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bmckenney

I find that the Cardas math works very well, but it results in the speakers being very far out in the room.  I recently re-did my placement after adding a good amount of absorption.  I used the non-dipole algorithm before which had my speakers 5.3 feet out from the front wall and 3.3 feet from the side walls.  But my speakers are dipoles.  I thought it sounded pretty good and I didn't want to use the dipole algorithm because that would put them out 6 feet (distance from side walls remains the same).  I wasn't totally convinced I was getting ideal acoustics with the recent addition of traps so I decided to try the dipole math and moved them out to 6'.  While 5.3 feet sounded pretty good in that it I had decent 3D staging and imaging and nice room energy and dynamics, it is really nothing compared to using the dipole distance out.  I am pretty sure the room treatment is really highlighting how good this sounds, which I'm glad for, but the placement is so important clearly. 

I should note that in the past I did trying moving further out from 5.3 feet but not to 6 feet, but it made the results worse so I went back to 5.3 feet.

Either algorithm does put the speakers well out in the room and even with non dipoles 5.3 feet is asking a lot.  But it is worth it.  For the Cardas math to result in finding two good locations, and really nailing the dipole position, is impressive to me and makes me a big believer in his work.

I can also say that his distance from the side wall math works spot on to.  My speakers do look close together compared to most setups I've seen, but it works.  If I spread them further apart I loose energy.  A lot of people think they get a wider soundstage with the speaker placed far apart, but they might not realize that it worsens things like dynamics and room energizing factors.  And they might not realize that when they are close together, and setup is right, you get a super expansive soundstage well beyond the speakers.

In my opinion for a typical rectangular room his method is the way to go.

I have noticed so many pictures of rooms where it looks like the speakers are too close to the front wall, and too far apart as well.  It's hard to say what the dimensions of the room are exactly, but from the pictures I've seen it really looks like people are not using the Cardas math.  And that is with rooms with treatment too.

There are some speaker designs that are supposed to work close to the front wall, like some of the UK designs such as Rega (because that market has smallish rooms), probably from a tonal or bass response point of view, but I can't imagine this would offer up an expansive, deep, 3d sound.

Anyway, I'm a big believer in the Cardas speaker positioning math, for a typical rectangular room with speakers on the short wall.  And I recommend that if you are not using it and have the ability to do it (speaker cable length etc), you really should try it.  And for speakers on the long wall, the Audo Physiks nearfield approach works well too from my experience over the years.

Your tape measure and calculator are the most important tools for setup.  And you have to have the mind to want the best sound and push yourself to get the speakers right out in to the room.

I would love to hear if anyone that knows of another algorithm or approach that puts the speakers closer to the front wall and results in as good sound.

Bryan

bmckenney

No bites?  I'm surprised there isn't more interest in speaker placement discussions at an acoustics board.  It is probably more important than room treatment.  Think of it this way.  What do you think sounds better?  A well treated room with let's say poor speaker placement,  or a non treated room with excellent speaker placement.

I would say neither sounds great.  It is situation dependent and there will be cases where either might win hands down.  But my gut says IN GENERAL I'd rather have good speaker placement over a treated  room with poor speaker placement.

Bryan

James Romeyn

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I'm similarly surprised.

Between Gearge Cardas' and Allen Perkins' setup instructions I favored George's.  IIRC Allen's may have provided more linear bass but less overall.  At the time I chose George's method, mainly because it allowed for space behind the main listening area for a second row of listeners, necessary because the room was destined (and now is) dual use music and HT.  Allen's method places the main seating against the rear wall.   

There's advantages to both.  Taste and purely subjective considerations like mine above will affect one's choice.  Both methods are worth trying.  It's work but it's part of the fun of the hobby.

Above experiments were w/ full range speakers.  I've since become a rabid believer in Dr. Earl Geddes' multi-sub approach, exceeding the performanc of any fullrange speaker IMHO.  The worse one's room modes and the more critical is one's desire to replicate the sound of bass in large rooms, the greater is the performance advantage of Earl's advice.
 

rockadanny

I cannot in the audio/Living Room as it is oddly shaped with no two walls even close to being the same with openings all over the place, plus cathedral ceiling, plus a fifth wall (free-standing) to boot. Therefore I've complied with the WAF math method instead. This is the basic formula:
Quote
Nuh-uh. You are NOT putting that thing there. Not in MY (fill in the blank).
This formula is universal - just fill in the blank - as it applies not only to all rooms in the house, but also in the bedroom.  :lol:

mjosef

Though my room is somewhat rectangular, its hardly typical, methods that tie placements to a set formulae does not apply in my case.
MasterSet which does not require rigid measurements, works for me because its works with the room you have...

bmckenney

Though my room is somewhat rectangular, its hardly typical, methods that tie placements to a set formulae does not apply in my case.
MasterSet which does not require rigid measurements, works for me because its works with the room you have...

My room isn't perfectly rectangular either, but it is close enough to it.  I have a big vaulted ceiling that slopes up from right to right across the soundstage.  And I have a big opening on the back right side.  But I averaged the ceiling height and used the three complete walls for the rectangle dimension and the Cardas math seems to work fine.  I know it isn't going to work for some rooms because of structure, but it should for most.

I've heard of the Masterset placement method and was intrigued by it because a lot of all the reports of great results.

I'd be seriously interested in what your room dimensions and speaker locations are.  And what kind of speakers you have.

Bryan

jimdgoulding

I cannot in the audio/Living Room as it is oddly shaped with no two walls even close to being the same with openings all over the place, plus cathedral ceiling, plus a fifth wall (free-standing) to boot. Therefore I've complied with the WAF math method instead. This is the basic formula:
Quote
Nuh-uh. You are NOT putting that thing there. Not in MY (fill in the blank).
This formula is universal - just fill in the blank - as it applies not only to all rooms in the house, but also in the bedroom.  :lol:
You crackin me up, dude.  Good post.

For sure, placement within the room and the room itself is fundamental to achieving the best from our systems.  I have to be careful in my small room (15x12x8) that the lower midrange doesn't get too bloomy so my equilateral triangle is somewhat larger than Cardas recommends and the distances from the walls behind my seat and my speaks are different from one another.  I know some guys don't or can't experiment with this.  If you can, do it.  Even the degree of toe in can matter.  Use a tape measure or a laser gizmo or something and record where you've been.  I'd even go so far as to recommend that a person makes notes about what they notice at this or that location with or without criteria.

mjosef

Quote
I'd be seriously interested in what your room dimensions and speaker locations are.  And what kind of speakers you have.

My room is about 11 1/2- 9 1/2 W. X 15 1/5 L. The width varies every 5ft. starting at the front wall(where my stereo is located)  and ending up the narrowest at my sitting position. The varying wall is the right wall. Behind my seating position is a big opening (no door, just a curtain with bookcases creating a sort of short hallway)to my bedroom. Right wall is the wall to outside, its a brick wall with plaster. Left wall is inner wall of the apt. building with the apt. entry door, and next to that the bathroom and to the front the kitchen(ette). This is a typical Brooklyn apt. The kitchen is so small that I have to put my fridge at the entry to the kitchen, ie in the stereo/HT room, and it takes up about 3ft. of the width of the front of the room. So there goes any resemblance to a rectangular shape.
Plus there are other shelving units crowding the corners at the listening end. Ceiling is a nice height about 9 1/2 ft.

Speakers are about 53(L) and 55(R) inches from front wall and about 40/43" from sides walls, bearing in mind that there are objects filling those spaces. They are about 5 ft apart and I sit about 7-8 ft away. Speakers are VMPS RM1, my gallery has a few shots of my system but not in the current location(speakers ie).
As you can see none of my measurements are uniform...I get a nice centered image that remains anchored regardless of whether I shift my seat 2 ft. to left or right.  I lose a little sparkle in the highs when I stand up, but that is the character of this speaker model. The soundstage is about 6ft deep behind the speakers, and I get a nice wide envelope sound effect with sounds sometimes emanating from my left and right.

stereocilia

My experiments show that I prefer a distant back wall to a distant front wall when possible.  As long as the front wall is 2.5 feet behind the speakers and there is nothing between them then I'm not noticing any soundstaging artifacts.  I think that puts me in the minority (which is where I probably belong anyway :)

jimdgoulding

I cannot in the audio/Living Room as it is oddly shaped with no two walls even close to being the same with openings all over the place, plus cathedral ceiling, plus a fifth wall (free-standing) to boot. Therefore I've complied with the WAF math method instead. This is the basic formula:
Quote
Nuh-uh. You are NOT putting that thing there. Not in MY (fill in the blank).
This formula is universal - just fill in the blank - as it applies not only to all rooms in the house, but also in the bedroom.  :lol:
You crackin me up, dude.  Good post.

For sure, placement within the room and the room itself is fundamental to achieving the best from our systems.  I have to be careful in my small room (15x12x8) that the lower midrange doesn't get too bloomy so my equilateral triangle is somewhat larger than Cardas recommends and the distances from the walls behind my seat and my speaks are different from one another.  I know some guys don't or can't experiment with this.  If you can, do it.  Even the degree of toe in can matter.  Use a tape measure or a laser gizmo or something and record where you've been.  I'd even go so far as to recommend that a person makes notes about what they notice at this or that location with or without criteria.
Oh, I left out measurements . . My speaker cabinets, Meridian M20 actives not made for a long time, are 7" wide and 14.5" deep and from the front centerpoint of my cabinets they are 52" off the wall behind them and 35.5" from the side walls (73" apart).  My head is 48" from the wall behind me.  The wall behind me opens on to a diagonal staircase and on the one side where it joins with the sidewall sits a shallow secretary w/o glass doors as a diffusor (I even stagger the drawers).  Two GIK panels rest along the side walls in front of the plane of my speaks.  The net gain is a stage that belies my room size in the best way possible . . breadth and depth of field.  Imaging is vibrant and palpable aided by an ARC tube pre and, well, you know :wink:.   

bmckenney

Quote
I'd be seriously interested in what your room dimensions and speaker locations are.  And what kind of speakers you have.

My room is about 11 1/2- 9 1/2 W. X 15 1/5 L. The width varies every 5ft. starting at the front wall(where my stereo is located)  and ending up the narrowest at my sitting position. The varying wall is the right wall. Behind my seating position is a big opening (no door, just a curtain with bookcases creating a sort of short hallway)to my bedroom. Right wall is the wall to outside, its a brick wall with plaster. Left wall is inner wall of the apt. building with the apt. entry door, and next to that the bathroom and to the front the kitchen(ette). This is a typical Brooklyn apt. The kitchen is so small that I have to put my fridge at the entry to the kitchen, ie in the stereo/HT room, and it takes up about 3ft. of the width of the front of the room. So there goes any resemblance to a rectangular shape.
Plus there are other shelving units crowding the corners at the listening end. Ceiling is a nice height about 9 1/2 ft.

Speakers are about 53(L) and 55(R) inches from front wall and about 40/43" from sides walls, bearing in mind that there are objects filling those spaces. They are about 5 ft apart and I sit about 7-8 ft away. Speakers are VMPS RM1, my gallery has a few shots of my system but not in the current location(speakers ie).
As you can see none of my measurements are uniform...I get a nice centered image that remains anchored regardless of whether I shift my seat 2 ft. to left or right.  I lose a little sparkle in the highs when I stand up, but that is the character of this speaker model. The soundstage is about 6ft deep behind the speakers, and I get a nice wide envelope sound effect with sounds sometimes emanating from my left and right.

I don't see your speaker specs on the VMPS website but I assume they are direct radiators, not dipoles.  If I use an average width of 10.5 feet and plug that in to the Cardas calculator, it results in a distance out from the front wall of 4.7 feet (roughly 54 inches) and 2.9 feet from the side walls (call it 35 inches).  That is very close to what you have for location from the front wall using the Masterset method, which is probably more than a coincidence and it is interesting how the trial by listening approach using Masterset resulted in the same distance as Cardas math does.  And your speakers are closer together than the Cardas method.  That's interesting and might reflect the non-symetrical dimensions of the room or furniture.  Have you tried them 35 inches from the side wall, or is that not possible?

Edit:  I have not done a lot of experimentation with distance from the side wall, but I have found that if I move the speakers closer to the side wall than what Cardas results are, spreading them apart more, I lose tone and dynamics (which is what Jim Smith says in his book Get Better Sound).  If I move them closer together I get a more homogenized, condensed, less open sound.

bmckenney

I cannot in the audio/Living Room as it is oddly shaped with no two walls even close to being the same with openings all over the place, plus cathedral ceiling, plus a fifth wall (free-standing) to boot. Therefore I've complied with the WAF math method instead. This is the basic formula:
Quote
Nuh-uh. You are NOT putting that thing there. Not in MY (fill in the blank).
This formula is universal - just fill in the blank - as it applies not only to all rooms in the house, but also in the bedroom.  :lol:
You crackin me up, dude.  Good post.

For sure, placement within the room and the room itself is fundamental to achieving the best from our systems.  I have to be careful in my small room (15x12x8) that the lower midrange doesn't get too bloomy so my equilateral triangle is somewhat larger than Cardas recommends and the distances from the walls behind my seat and my speaks are different from one another.  I know some guys don't or can't experiment with this.  If you can, do it.  Even the degree of toe in can matter.  Use a tape measure or a laser gizmo or something and record where you've been.  I'd even go so far as to recommend that a person makes notes about what they notice at this or that location with or without criteria.
Oh, I left out measurements . . My speaker cabinets, Meridian M20 actives not made for a long time, are 7" wide and 14.5" deep and from the front centerpoint of my cabinets they are 52" off the wall behind them and 35.5" from the side walls (73" apart).  My head is 48" from the wall behind me.  The wall behind me opens on to a diagonal staircase and on the one side where it joins with the sidewall sits a shallow secretary w/o glass doors as a diffusor (I even stagger the drawers).  Two GIK panels rest along the side walls in front of the plane of my speaks.  The net gain is a stage that belies my room size in the best way possible . . breadth and depth of field.  Imaging is vibrant and palpable aided by an ARC tube pre and, well, you know  :o.

Jim, with those dimension, assuming your speakers are direct radiators, Cardas results are that the speakers should be about 60 inches from the front wall.  You are about 8 inches to close to the front wall.  And they should be about 40 inches from the side walls, so your speakers are to close to the side walls, spread too far apart.  It seems to me that you are a perfect candidate to try the Cardas placement and I would wager a lot of beer that you would get a huge improvement if you tried it.   From my experience with speaker placement, knowing what it sounds like when speakers are not far enough out in to the room and too wide apart, I'd say orders of magnitude improvement.

jimdgoulding

I'm familiar with Cardas' math, thanks.  You realize that my room is pretty small?   But, its been a long time so I may give it another go over the weekend.  There may be a place inbetween Cardas' configuration and your side walls that you haven't hit upon yet.  What dipoles are you using?

Btw, I think I recognize your name from somewhere.  Do you frequent other rooms like AC?

bmckenney

I'm familiar with Cardas' math, thanks.  But, its been a long time so I may give it another go over the weekend.  There may be a place inbetween Cardas' configuration and your side walls that you haven't hit upon yet.  What dipoles are you using?

There isn't a place that is better for distance from side walls.  When too close to the side walls from the math results, the sound is leaner, less dynamic, worse tone.  When too far from the side walls the sound is congested.  I tried countless ways.  I have tried many ways for both distances actually and nothing is as good compared to the Cardas math.  That is why I believe in it.  And whether using dipole or direct radiators, the distance from the side wall is the same.  The difference with dipoles is the speakers are further from the front wall than direct radiators.  I guess dipoles need more room to breath, or more time for the back wave to reflect off the front wall in a way that sounds good.  My speakers are Eminent Technology LFT8s which have a dipole magnetic planar driver that runs from a couple of hundred hertz up to I think 8Khz which where most of the music is.  The tweeter magnetic driver is not dipole in my version but is in previous models, not that it matters as much as the midrange.

jimdgoulding

I hear you.  What is your room size?  Your speakers are famous for their mid range.  Lucky boy. 

bmckenney

My room is 22' long by 12' wide.  The ceiling is vaulted open beam that slopes from left to right from about 8' to 11'.  Since ceiling height is a parameter for the Cardas dipole calculator for calculating distance from the front wall, I used an average of 9.5' for height, which results in speakers out 6'.  I wasn't using the dipole calculator at first, just the direct radiator, and while it sounded quite good, the dipole works much better but does sacrifice a bit of living room space.  Well worth it though.

Housteau

I think the Cardas Method is certainly valid for one piece speaker systems.  Like most others though, it is sometimes a compromise between attributes, such as best low end response, best imaging etc.  There seems to be very few absolutes and universal approaches in audio.  There are just too many variables.

For my two piece speaker system I have found that the Audio Physics Speaker Placement Method works best for my room and system.

http://www.audioasylum.com/scripts/d.pl?audio/faq/audiophysic.html

In a way the bass towers are following a similar Cardas plan, but the higher frequency units and listening position are not.

The beauty of such a two piece system is that it is nearly infinitely adjustable in just about every way, but the big problem with that has to do with it being nearly infinitely adjustable in just about every way :).

Although I love big speakers and the visuals they present, I don't want to localize them once the music starts.  I want them to completely disappear.  My current set up does thit for me.  My upper frequency speakers are about 8 feet apart along a 21 foot wide front wall, yet the presentation can stretch from side wall to side wall if the recording permits.




jimdgoulding

BMC, cool.  No living space for me to have to worry about cause it's MY room.  Last home I owned had a small barn that I paneled in and set up my Acoustat Three dipoles in very nearly the Cardas fashion.  Just me, a pot belly stove and a wine rack.  Weren't bad for a country boy.  I'm gonna play around in my room this weekend. 

I'm a fool for a dedicated chair, too.  Single seat, real fabric and shoulder height.  Confess that I cringe when I see guys using high back leather recliners.  Those could be improved upon. 

jimdgoulding

I think the Cardas Method is certainly valid for one piece speaker systems.  Like most others though, it is sometimes a compromise between attributes, such as best low end response, best imaging etc.  There seems to be very few absolutes and universal approaches in audio.  There are just too many variables.

For my two piece speaker system I have found that the Audio Physics Speaker Placement Method works best for my room and system.

http://www.audioasylum.com/scripts/d.pl?audio/faq/audiophysic.html

In a way the bass towers are following a similar Cardas plan, but the higher frequency units and listening position are not.

The beauty of such a two piece system is that it is nearly infinitely adjustable in just about every way, but the big problem with that has to do with it being nearly infinitely adjustable in just about every way :).

Although I love big speakers and the visuals they present, I don't want to localize them once the music starts.  I want them to completely disappear.  My current set up does thit for me.  My upper frequency speakers are about 8 feet apart along a 21 foot wide front wall, yet the presentation can stretch from side wall to side wall if the recording permits.
Looked at your gallery, mate.  Think I could find a little happiness in there. 

bmckenney

I think the Cardas Method is certainly valid for one piece speaker systems.  Like most others though, it is sometimes a compromise between attributes, such as best low end response, best imaging etc.  There seems to be very few absolutes and universal approaches in audio.  There are just too many variables.

For my two piece speaker system I have found that the Audio Physics Speaker Placement Method works best for my room and system.

http://www.audioasylum.com/scripts/d.pl?audio/faq/audiophysic.html

In a way the bass towers are following a similar Cardas plan, but the higher frequency units and listening position are not.

The beauty of such a two piece system is that it is nearly infinitely adjustable in just about every way, but the big problem with that has to do with it being nearly infinitely adjustable in just about every way :).

Although I love big speakers and the visuals they present, I don't want to localize them once the music starts.  I want them to completely disappear.  My current set up does thit for me.  My upper frequency speakers are about 8 feet apart along a 21 foot wide front wall, yet the presentation can stretch from side wall to side wall if the recording permits.

Your room is awesome!  Nice job with the DIY room treatment too.  Those coverings look really, really good in that room.  I have no idea about placement for multi cabinets but I'm familiar with the AP method.  I used it to great affect when I had some direct radiator monitors placed on the long wall in a pseudo nearfield configuration.  Great dynamics and a very, very wide and seamless wall of sound, but over the long haul I found it too in my face.  And it was too wide but not deep enough, too exaggerated from a recording space dimensions point of view. It doesn't look like your setup is really nearfield at all and I am surprised that the AP method works in that room but since you have multiple cabinets all bets are off!  Once again, very nice looking room.