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

0 Members and 1 Guest are viewing this topic. Read 107648 times.

macrojack

  • Restricted
  • Posts: 3826
A grouch? Omigod, stvnharr, if you call me that again I'm gonna tell your mom you're being mean to me. Besides, I think I've cracked your code....when you say master set you really are saying masterbate. That would explain your enthusiasm. And your insistence on hands on experimentation.

And don't send me anymore prissy P.M.s. I won't respond.

On the other hand, I should explain my initial comment. If you have room correction, equalization and an electronic crossover, you can move the balance of your speakers' response all over the room. It is especially easy if you have something directional like horns.
Boundaries are then much less of a concern and you won't need so many band aids (room treatments).

As others have attempted to say earlier, there is no goal other than self-satisfaction. If Stvnharr's histrionics float your boat, then have a nice voyage. If instead, you like to listen with eleven speakers and quad subs, you go, girl. Absolute is a magazine publisher's way of enlisting subscribers. There is nothing higher or more pure than your own preference.
I have a good friend who is a piano tuner/DIY audiophile. I have to resist the temptation to hire him to "tune" my system. I have learned over the years that I will get used to it no matter how it sounds and that I will perpetually think about how to squeeze more out of it even though I haven't really cared about such things in years. It's a great system but it mostly just plays FM and TV. Sometimes we play records or CDs but certainly not daily. I got away from that habit when the kids came along and I never really picked up on it again the way I once did before. Once I got married I lost touch with master setting, gained weight and got grouchy.

jimdgoulding

Some of the things that have been said are popping out the second time around.  Get to those in a second.  First, I’d like to suggest what Steve is likely getting based on his gallery photos.  Images are being pushed forward and are made very vivid.  This is due to both his near rear wall placement and his toe-in.  This is adding coloration to my thinking and here’s why.  Steve has suggested that MS releases design goals made in the design stage (of speakers).  First up, I don’t think most speakers are designed for near wall placement and, if I am not mistaken, frequency response and time studies are made in the lab when speakers are free standing (the exception would be those that are designed for near wall placement).  I’ll gladly stand corrected if one of our circle of manufacturers cares to inform.  Steve has also said that the object of MS is to prevent time and phase error.  Near wall placement is certainly more like soffit mounting of drivers, and maybe that’s the goal, but should we believe that time and phase error is insurmountable in rooms with free standing speakers?  Again, I would welcome hearing from one of our circle of manufacturers.  I’m having a little trouble ingesting some of the comments made about MS.  Some sound like hyperbole to me and I suspect may not have originated with person sayin.

A note to Laura.  This guy who is visiting you, might he have an agenda?  Think he might be a wee bit suggestive?  Allow him to tune up your room, not your head.  In fact, I suggest you remove yourself from the process until he is ready for you to listen.  Then, he should zip it.  I know he will need your help moving things around and that will give him an opportunity to talk.  Talk about sports or something.  And if you think its good idea, make a score sheet of some kind and a rating system.  I know there will be positive things but look for trade offs in the big picture.  Be cool.  Listen critically.  You can enjoy all or whatever later.  The guys on this thread will likely tune in.  I know I will. 

stvnharr

  • Full Member
  • Posts: 741
A grouch? Omigod, stvnharr, if you call me that again I'm gonna tell your mom you're being mean to me. Besides, I think I've cracked your code....when you say master set you really are saying masterbate. That would explain your enthusiasm. And your insistence on hands on experimentation.

And don't send me anymore prissy P.M.s. I won't respond.


You have such a nice way with words!

vinyl_guy

Have you guys and gals noticed how many circles have a thread going about speaker placement? I just did a cruise through several circles and speaker placement appears to be a hot and continuing topic of conversation. Very interesting.

Laura

stvnharr

  • Full Member
  • Posts: 741

This all should not be about ego or personality.
« Last Edit: 15 Jan 2010, 08:04 pm by stvnharr »

macrojack

  • Restricted
  • Posts: 3826
When we can't afford or justify new gear, or we are scared out of our wits by economic indicators, we take refuge in rearranging the deck chairs. It's normal.

jimdgoulding

Steve-  Sorry, man, I respect that you love your set up.  Really, I can very much relate to that!  What I said was that some of the things I've read in your posts could do with some validation.  Sorry that offended you.  My thinkin and sayin that your placement and toe-in is pushing images forward and making them very vivid is not a criticism even if it were fact.  Some listeners would dig that.  Never said MS wouldn't work.  I have doubts that it would to my criteria, think I said that.  But, hey, that's a personal problem, right?  Glad you can listen to string quartets now.  You be cool.   

Quiet Earth

  • Full Member
  • Posts: 1788
Steve,
I want to thank you for taking the time and space in this thread to explain master set to the best of your ability. I had never heard of it before and even though I think I am already doing the master set without knowing it, I have a new way of looking at things and a new way to evaluate speaker placement. Whether it works for me or not I appreciate the source of information.

I come here to learn and to share ideas about audio. And for a little companionship. Thanks to everyone else who has had something constructive to say on the subject of speaker placement. I will follow the thread with continued interest.

jimdgoulding

Know what, Steve?  I most regret not making my post TO you.  I am very sorry about that and shoulda thought better.  Next time, I will.  And what Earth said.

jhm731

The graph is essentially meaningless as it was not done in a Master Set setup. Just having speakers close to a wall does not make a speaker placement a Master Set.  It's just another out of phase placement.


"It's just another out of phase placement"  :lol:

Shown below is my current listening position measurement verses the Stereophile 2009 speaker of the year:










vinyl_guy

Steve,
I want to thank you for taking the time and space in this thread to explain master set to the best of your ability. I had never heard of it before and even though I think I am already doing the master set without knowing it, I have a new way of looking at things and a new way to evaluate speaker placement. Whether it works for me or not I appreciate the source of information.

+1 :thumb:

Quote
I come here to learn and to share ideas about audio. And for a little companionship. Thanks to everyone else who has had something constructive to say on the subject of speaker placement. I will follow the thread with continued interest.

I couldn't agree more or said it any better.  :beer:

Laura


Nyal Mellor

  • Industry Participant
  • Posts: 250
  • Founder - Acoustic Frontiers.
    • Acoustic Frontiers
Two things

1) On the subject of placing loudspeakers near boundaries: placing any box speaker, dipole or omni-directional speaker near a boundary will cause phase interference (aka speaker boundary interference). In addition it will cause low frequency gain (aka boundary gain), typically 3db for each boundary. Some speaker designers factor this into their designs, others do not. The only speaker designs to avoid boundary interference are either highly directional (e.g. horns) or in wall. A box speaker is basically omni directional at low frequencies.

read this article http://www.synaudcon.com/website08/VOL36_DEC08_Boundaries.pdf

2) A good and simple way to score sound is against the Home Acoustics Alliance checklist (Focus, Envelopment, Clarity, Response and Dynamics).

stvnharr

  • Full Member
  • Posts: 741
Two things

1) On the subject of placing loudspeakers near boundaries: placing any box speaker, dipole or omni-directional speaker near a boundary will cause phase interference (aka speaker boundary interference). In addition it will cause low frequency gain (aka boundary gain), typically 3db for each boundary. Some speaker designers factor this into their designs, others do not. The only speaker designs to avoid boundary interference are either highly directional (e.g. horns) or in wall. A box speaker is basically omni directional at low frequencies.

read this article http://www.synaudcon.com/website08/VOL36_DEC08_Boundaries.pdf

2) A good and simple way to score sound is against the Home Acoustics Alliance checklist (Focus, Envelopment, Clarity, Response and Dynamics).

Correct!
When speakers are placed very close to a boundary, very close as in a foot or so, the whole wall becomes like the baffle.  This can be included as part of the design of the speaker, if the designer so decides.

In doing the MS protocall, one moves one speaker out from the wall until the sound of the speaker is decoupled from the wall. This is easily heard as the sound all seems to come from that one speaker.  This will happen at different distances with different speakers.  It's not a fixed dimensional measurement.  And the decoupling happens fairly close to the wall, closer than conventional thought allows.

Sumiko has done a lot of research on room boundary effects, and has kept it all inhouse. Pity really, but it's there's to do as they please.

stvnharr

  • Full Member
  • Posts: 741

"It's just another out of phase placement"  :lol:


It's good to have a sense of humor! Glad to have contributed!

My comment refers the placement on one speaker with in regards to the other one.  Any competent speaker should designed to be phase correct with respect to the drivers in that one speaker.  But the placement of the two speakers in the room also needs to be phase correct with each other for maximum sound benefit.  This is what M.A.S.TE.R.S. is about, and the Master Set protocall is a way of getting there.
In that respect it is quite different from common thought, and maybe a hard concept to grasp.  It's a lot easier to understand by hearing, than reading about it.

Nyal Mellor

  • Industry Participant
  • Posts: 250
  • Founder - Acoustic Frontiers.
    • Acoustic Frontiers
Correct!
When speakers are placed very close to a boundary, very close as in a foot or so, the whole wall becomes like the baffle.  This can be included as part of the design of the speaker, if the designer so decides.

In doing the MS protocall, one moves one speaker out from the wall until the sound of the speaker is decoupled from the wall. This is easily heard as the sound all seems to come from that one speaker.  This will happen at different distances with different speakers.  It's not a fixed dimensional measurement.  And the decoupling happens fairly close to the wall, closer than conventional thought allows.

Sumiko has done a lot of research on room boundary effects, and has kept it all inhouse. Pity really, but it's there's to do as they please.

If this is as you say then one should be able to measure this effect. Will this effect be measurable with dipoles or only with box speakers? If dipoles I can do some measurements to see whether this is true, if not then maybe someone with a box speaker can try.

If this MS theory is correct one should not be able to see phase interference is what you are saying. Correct?

Nyal Mellor

  • Industry Participant
  • Posts: 250
  • Founder - Acoustic Frontiers.
    • Acoustic Frontiers
It's good to have a sense of humor! Glad to have contributed!

My comment refers the placement on one speaker with in regards to the other one.  Any competent speaker should designed to be phase correct with respect to the drivers in that one speaker.  But the placement of the two speakers in the room also needs to be phase correct with each other for maximum sound benefit.  This is what M.A.S.TE.R.S. is about, and the Master Set protocall is a way of getting there.
In that respect it is quite different from common thought, and maybe a hard concept to grasp.  It's a lot easier to understand by hearing, than reading about it.

I guess you are referring to the phase response of REFLECTED sounds (which are a lot of what we here in a room). LR speakers will only be in phase for DIRECT sound if they are same distance from listener. So we must be playing with somekind of psychoacoustic balance of direct vs reflected sound and how they are related from a phase perspective.

jimdgoulding

As a result of this discussion, I ultimately tightened up my triangle some and to precisely equilateral distances and played Britten's Turn of the Screw opera (Naxos) and here's what happened.  My stage expanded out beyond the speakers panoramically.  Piano near field left and larger behind the speaker, orchestra receded, and the five player/singers appeared at different places on the stage as tho they moved about just like live.  Things sounded very even.  Sitting a little further away and where I most often sit, images have more body density but become smaller and the stages narrows as if I had moved back several rows in the hall.  I listened to other music but is was on this recording, so far, where the differences were most dramatic.

I'm thinking that moving away some more, room gain is coming more into play and/or the beams are combining more.  I might yet try MS placement at some point for comparison if I am able to learn how to do it right in spite of the fact it makes no sense to me or the sense it does make isn't good.  Like the lady says, nothing ventured, nothing gained. 

flintstone

I put a lot of listening hours in before I found the spot where my speakers sound best...tweaking for months, and finally outstanding sound. It's just to bad I never heard of the CARDAS setup method way back then.

A couple of years ago, when I did run across the CARDAS setup guide...I checked it out. It turned out to be within inches of where I was already at  :banghead:

Although I enjoyed all the listening...my speakers aren't easy to move around....so the CARDAS method would have helped me a lot in my room.  (I know it doesn't work well in all rooms)


Dave



stvnharr

  • Full Member
  • Posts: 741
If this is as you say then one should be able to measure this effect. Will this effect be measurable with dipoles or only with box speakers? If dipoles I can do some measurements to see whether this is true, if not then maybe someone with a box speaker can try.

If this MS theory is correct one should not be able to see phase interference is what you are saying. Correct?

Nyal,
Sorry to be so slow with a reply, but I have been thinking about all this.

It would be great if proper measurements could be taken as that would make the setup fairly easy.  But one would have to measure each speaker while both are playing and without interference from the other speaker. That might be difficult, if not impossible.  Essentially this is what is done during the setup, only by ear.

I think my comment about the two speakers being out of phase with each other is a bit hard for most to comprehend.  So instead of trying to explain that a little more, and muddy up things even further, I'll just use an analogy and leave it at that.

I want to use the analogy of focusing binoculars. The process is similar, although binoculars are visual and speakers are aural.  But with binoculars there are two lens that get focused into a single vision.  With speakers there are two speakers that get focused into one sound.  I think the key word here is FOCUS, and that's not a common term with speaker setup.  But with MS, one speaker gets set as an "anchor", and then the other speaker is then set to match the anchor, by essentially focusing in to it.

With binoculars the first step is to adjust the center pivot to ones head and eyes.  In MS we first spread the speakers apart as far as the room will allow and still keep a centered mono sound image and the initial equilateral triangle setup positioning.
The second step with binoculars is to adjust the focusing dial that controls both lens to focus perfectly with the fixed lens. You close one eye, or just ignore the other one, and focus with just that one eye.  With MS the anchor speaker is set in a similar fashion as earlier described. Instead of a focus point, the spot of smoothest bass sound is used as a focusing spot.
The third step with binoculars is to adjust the adjustable lens so that that lens then matches the fixed lens and makes a perfect focus. With MS, we adjust the second speaker to match the anchor speaker as the room and speaker allow.  Just as everyones eyes tend to be a little dissimilar, so is everyones listening room and speaker.  Using the spot of smoothest bass in the anchor speaker, it is possible to get a match with the adjustable speaker, but it's hard.  However, if the two speakers are in perfect focus with each other, the sound becomes a single stable sound and you just adjust the adjustable speaker until this occurs. You can move around the room a bit until the sound no longer moves with you. An when the two speakers are perfectly focused together the centered vocal sound, of the setup disc becomes very lifelike that is fairly easy to discern.  A lot of experimenting however, is needed to get this final touch!

I don't know if the binocular analogy helps anyone understand the MS procedure, or the desired end result, but I hope so.

Let me make just one clarification, if I may do so.  I have used the terminology of setting the speakers until a single sound emerges.  Well, the speaker, no matter where they sit in a room, will always sum into the appearance of a single sound.  But with a true single sound, the sound will stay stable in the room as the listener moves around in the room as the sum of the two speakers does not change in any real way. The only thing that changes is the listeners perspective to that sound.  This is similar to sitting in different seats in a concert venue.  When the sound moves around the room with you as you yourself move around the room, it means that there is a different sum of the two speakers at each and every place the listener goes.  A centered vocal is the easiest scenario to discern this.  Move to the right, and the voice moves to the right.  Move to the left, and the voice moves to the left.  This does not occur in a concert venue unless there is no amplification and the singer actually moves across the stage.  In a recording, the singer is fixed in the middle, and should always stay there.
Again, hope this helps rather than muddy things up more.

Steve

Browntrout

I think there are different types of reproduction in a listening room. You can have an open sound that fills the room and recreates the experience of actually sitting in the venue or you can have a more focused more detailed sound that draws you into a recording but sounds like you are listening to a recording. I think speaker placement is the major factor in determining which one of these you experience.