[stvnharr]

I was thinking waterfall plots... combination of impulse and frequency response.. This might reveal what folks are commenting on w.r.t bass response and clarity/imaging.  Not sure really - just a thought.

- Doug

Doug,
Those all look like single speaker measurements, and are a great tool for selecting a speaker to purchase. But for setting speakers in a room, I think you would need some sort of measurement of both speakers operating at the same time.

Steve

[DougSmith]

Doug,
Those all look like single speaker measurements, and are a great tool for selecting a speaker to purchase. But for setting speakers in a room, I think you would need some sort of measurement of both speakers operating at the same time.

Steve

I was thinking of in-room response of the entire system from the listening position(s).  Things like smoothness of the bass response, dropouts at certain frequencies, and decay times at different frequencies would be evident there.  It wouldn't tell you anything about imaging per se (no problem doing that by ear), but it could help to sort out the basics and perhaps indicate a "preferable" set of parameters that could be achieved by anyone with the aid of those types of measurements - sort of an extension of the kinds of things Floyd Toole talks about in his book. 

- Doug 

[stvnharr]

I was thinking of in-room response of the entire system from the listening position(s).  Things like smoothness of the bass response, dropouts at certain frequencies, and decay times at different frequencies would be evident there.  It wouldn't tell you anything about imaging per se (no problem doing that by ear), but it could help to sort out the basics and perhaps indicate a "preferable" set of parameters that could be achieved by anyone with the aid of those types of measurements - sort of an extension of the kinds of things Floyd Toole talks about in his book. 

- Doug

If that can be done, then it would be very useful I would think.

[Jeffrey Hedback]

I would like to jump in from an acoustics perspective, although everything I'm about to state has been said in some form or another...maybe just not in same words.

There are some metrics that can look on paper like a great listening space such as:
- Frequency Response +/- 6dB or better
- Decay time from 50Hz to 1KHz within 3:1 ratio (some say 2:1)
- No significant modal ringing (goes hand in hand with first two points)
- The amplitude of room reflections is 15 dB down from direct signal.  Note: this is a sticky point as a dedicated listening room by it's nature puts the listening beyond the critical distance where room energy is more significant than direct sound...but this is a way to factor discrete reflections that can cause image shift through the use of Energy verses Time analysis.


None of those can tell you what the room sounds like.  Nothing can factor the way that transient signals propogate in the room which is a huge factor in the perceived quality of sound. 

In low frequency regions you have room/modal issues and then you have boundary coupling and interference.  These can be identified and modified by speaker/listening position.  This is really the main "trick" to the Master Set.  That deliberate process with "good ears" can certainly put a specific speaker in a very good location.  Add the right room treatments and the results can be more "universal" for that same room.  At high resolution analysis (1/12th octave or better) boundary interference nulls can look horrifying in a freq response graph.  But the human ear is designed to hear through (to a certain extent) narrow nulls. We are much more affected by sharp peaks.

As for imaging...too many variables in speaker/room relationship to comment on if just a speaker set could optimize imaging without some acoustical remedy.

What I admire about this thread is the awareness of this factor.  It's really such a primary part to the whole listening equation, easily as important as any component.  An analogy that comes to mind is one can own and string up a beautiful acoustic guitar, but you're not making music until you learn the notes/chords.  Speaker placement is the same as learning the notes/chords.

[jimdgoulding]

I was thinking of in-room response of the entire system from the listening position(s).  Things like smoothness of the bass response, dropouts at certain frequencies, and decay times at different frequencies would be evident there.  It wouldn't tell you anything about imaging per se (no problem doing that by ear), but it could help to sort out the basics and perhaps indicate a "preferable" set of parameters that could be achieved by anyone with the aid of those types of measurements - sort of an extension of the kinds of things Floyd Toole talks about in his book. 

- Doug

That would be a revealing and constructive thing, for sure.  I'd love to see this in Steve and Laura's room were it possible.  Mine, too.  Dan posted a near wall vs. Cardas set up frequency response sweep with his speakers if memory serves and looked about like what I would imagine.  That doesn't tell the story like what you've suggested would, tho.  Good to get input from you, Doug and Jeffrey.   

[DougSmith]

I would like to jump in from an acoustics perspective, although everything I'm about to state has been said in some form or another...maybe just not in same words.

There are some metrics that can look on paper like a great listening space such as:
- Frequency Response +/- 6dB or better
- Decay time from 50Hz to 1KHz within 3:1 ratio (some say 2:1)
- No significant modal ringing (goes hand in hand with first two points)
- The amplitude of room reflections is 15 dB down from direct signal.  Note: this is a sticky point as a dedicated listening room by it's nature puts the listening beyond the critical distance where room energy is more significant than direct sound...but this is a way to factor discrete reflections that can cause image shift through the use of Energy verses Time analysis.


None of those can tell you what the room sounds like.  Nothing can factor the way that transient signals propogate in the room which is a huge factor in the perceived quality of sound. 

In low frequency regions you have room/modal issues and then you have boundary coupling and interference.  These can be identified and modified by speaker/listening position.  This is really the main "trick" to the Master Set.  That deliberate process with "good ears" can certainly put a specific speaker in a very good location.  Add the right room treatments and the results can be more "universal" for that same room.  At high resolution analysis (1/12th octave or better) boundary interference nulls can look horrifying in a freq response graph.  But the human ear is designed to hear through (to a certain extent) narrow nulls. We are much more affected by sharp peaks.

As for imaging...too many variables in speaker/room relationship to comment on if just a speaker set could optimize imaging without some acoustical remedy.

What I admire about this thread is the awareness of this factor.  It's really such a primary part to the whole listening equation, easily as important as any component.  An analogy that comes to mind is one can own and string up a beautiful acoustic guitar, but you're not making music until you learn the notes/chords.  Speaker placement is the same as learning the notes/chords.

Thanks, Jeffery - very eloquent!  Yes, I knew there would be limitations.  So... the part about "None of those can tell you what the room sounds like.  Nothing can factor the way that transient signals propogate in the room which is a huge factor in the perceived quality of sound."...

This is interesting.  What could tell us about this?  How about stereo mics on a dummy head?  Could we measure something with that which could define a "good sounding room"?

-Doug
 

[JakeJ]

Hi Gang,

Here is a photo of member timtunz new speaker location thanks to his sound engineer friend.  The blue masking tape marks his previous Cardas setup.  Let's hope his friend joins the forum!  You can see Tim is now every bit as happy as Laura is. 

 

[jimdgoulding]

Jake-  Such propagandazing.  Have you no shame?  That's only Tim's semi happy face.

[JakeJ]

Nope, none.  I'll be posting my own pictures soon enough.

[jimdgoulding]

Nope, none.  I'll be posting my own pictures soon enough.

Veddy cool.

[timztunz]

Jake-  Such propagandazing.  Have you no shame?  That's only Tim's semi happy face.

Jim - I AM smiling!  LOL.  I'm in Brazil for a couple of weeks and only just got to where I have a decent Internet connection.  I'm glad Jon sent the picture to Jake and I'm glad Jake posted it because I did want everyone to see the dramatic difference in speaker location.  The only thing more dramatic is the improvement in sound in ALL regards.

Best luck to all and happy listening.

[jimdgoulding]

Jim - I AM smiling!  LOL.  I'm in Brazil for a couple of weeks and only just got to where I have a decent Internet connection.  I'm glad Jon sent the picture to Jake and I'm glad Jake posted it because I did want everyone to see the dramatic difference in speaker location.  The only thing more dramatic is the improvement in sound in ALL regards.

Best luck to all and happy listening.

Watch out for snakes and lost tribes of Indians up in those jungles when you're out there exploring for hallucinogenic plants.  See you when you get back.

[Nyal Mellor]

I would like to jump in from an acoustics perspective, although everything I'm about to state has been said in some form or another...maybe just not in same words.

There are some metrics that can look on paper like a great listening space such as:
- Frequency Response +/- 6dB or better
- Decay time from 50Hz to 1KHz within 3:1 ratio (some say 2:1)
- No significant modal ringing (goes hand in hand with first two points)
- The amplitude of room reflections is 15 dB down from direct signal.  Note: this is a sticky point as a dedicated listening room by it's nature puts the listening beyond the critical distance where room energy is more significant than direct sound...but this is a way to factor discrete reflections that can cause image shift through the use of Energy verses Time analysis.


None of those can tell you what the room sounds like.  Nothing can factor the way that transient signals propogate in the room which is a huge factor in the perceived quality of sound.

I think you've overstated this. Generally there is a very good correlation between what you can measure (flat frequency response, lack of modal ringing and reduced level of reflections ref direct sound) and observed sound quality. But I agree that one cannot tell how something sounds purely from measurements. The ears are a powerful tool and there is still a lot which we don't understand in terms of the correlation between measurements and what we hear. So measurements should be supplemented by critical listening.

Could you explain a bit more in terms of what you mean by 'the way transient signals propogate in a room'. Do you mean the frequency spectrum of reflected sound vs direct sound?

Thanks

[Jeffrey Hedback]

Hello Nyal,

Glad to explain.  I intended to mention (although it was poorly stated) that the transient portions of music (a percussive hand mute on acoustic guitar, a vocal plosive, etc) don't "propagate" in nice orderly fashions and don't behave in regard to on/off axis response of speakers.  They (transients) can be measured to some extent with Energy/Time Analysis, but a solution then takes experience to know what a "best case" remedy may be.  I didn't mean at all to overstate or understate acoustical measurements, just add perspective that measurements alone don't tell the full story.  So, acoustically yes...I do mean the frequency spectrum of reflected vs direct as long as you include the transient response of the speaker as part of the system.  We can hear this instantly in music, but it's tough to measure.

I like the deliberate process of the Speaker Set method.  You or I may look at the room modally and cut some time off the process in terms of locating speakers for better low frequency response.  But that in itself won't guarantee best soundstage, imaging or the above referred transient character of the system.

If a person understands the Speaker Set method and has a grasp on taking room measurements...now that's a great combination of the objective and subjective where your ears can verify what a frequency response graph, waterfall plot and Energy/Time graph show.

I recently designed acoustical treatments for a room with Wilson Sashas.  The speakers were set (initial not final) by Craig Hempell of Geoff Poor.  We listened to the room as-is and by all accounts the room was just short of wretched.  The majority of the treatments were installed that day allowing Craig to do the final set.  Acoustical testing pre/post verified the room issues being addressed and this helped Craig (who has an amazing skill set) in his craft.  Craig and I both commented on how beneficial our combined experiences were in the process and the end result was superb.  It all boils down to knowing what true tone is and knowing what factors get in the way.

I look forward to further discussions Nyal and thanks for your post.

[Nyal Mellor]

Hey Jeff thanks for your post.

I agree with what you say. I find measurements very useful to get good bass response & eliminating strong reflections but less useful in terms of calibrating final soundstaging, focus and envelopment. I'm currently using a methodical approach to this part of the voicing or calibration (with a floor grid, make small movements and listen, make small movements listen again) but its not MS, just because I haven't been exposed to it properly.

What do you use as pre/post comparison? Mostly findings from critical listening or also measurements?

[Jeffrey Hedback]

Hi Nyal,

To answer your question, I use REW whenever I feel comfortable hooking up to the clients system.  In a studio with active monitors, it's really no concern to hook up the system.  But in the specifc room I referred to earlier, I was not about to go into his VAC pre and amps to excite the room through the Wilson Sasha's.  I just have too many instances in the studio and live sound fields of cables and connections going bad.  So, (short-story-long...) I used a combination of Ethan's 1Hz tones with SLM (for LF) and reference material.  There is a piece by drummer Jim Brock (Pasajes disc) where the melody is doubled with clean electric guitar and flute.  In a room with time domain issues (early reflections of too great an amplitude that smear and skew imaging) the two instruments sound like one "foggy" sound.  In a room with proper reflection control, you hear the distinct nuances of pick on string as well as the breathy attack of flute.  It's a great reference in this regard.



BTW- I really like the 1 Hz resolution gained through Ethan's tones.  Sure it's laborious but you can really identify speaker/boundary and listener/boundary nulls at that resolution.

For just raw "first look" speaker locations, I look at thirds and fifths of the L & W dimensions.  My goal is to excite all modes a moderate amount rather than some a great deal, staying away from worst nulls.  Of course each room/speaker/listener combo is different.  Most recent, the combination of one fifth in from sidewalls and third off front wall is working well in dedicated rooms.

[Nyal Mellor]

Hey Jeff

Yeah I also find that reference tracks that you listen to regularly and are intimately familiar with on a reference system (hopefully your own) are very useful when doing critical listening. I've got quite a list and use different tracks for different purposes.

I'm surprised that you are worried about hooking up your measurement equipment. I guess maybe the cables and stuff get more battered in studio/live sound environment. In home audio I've no hesitation in hooking up my rig to 100k systems. Maybe I should!! EDIT - maybe I should also say that I have found REQ Wizard to be difficult to use across multiple systems, the level calibration process, whilst good for a beginner, is 'over smart' and won't let you take measurements when really the levels are fine. I've found ARTA to be better, all the knobs and dials are exposed (good if you know what you are doing) the only thing it really misses is a good waterfall/spectral decay graph.

[J. Royce Baron]

Unable to lock in MasterSet as described by Laura and Rod – You never miss what you never had.



Final placement with updated acoustic tratment. 

[jimdgoulding]

Spent Saturday morning at Tim's house listening to tunes.  Allow me to refresh you.  Tim has a big room like Laura's and tall multi driver speakers like Laura's but from a different designer.  Tim formerly had his speaks positioned using Cardas math.  His speaks today are positioned similarly to Laura's.  They are wider apart nearer the corners of his room and much further back nearer the wall.  His listening position is the same and looks very similar to Laura's from her photos.  Tim does not, however, have that little jig or difference from the rear wall of the "anchor" speaker and whatever the other speaker is called in the Master Set nomenclature.

Master Set purists may contend that this couldn't be correct, then.  OK, this is just about my experience at Tim's house, anyway, but his and Laura's set up is very similar in similarly large rooms and if you recall I had said that I think I was hearing at Tim's back when some of what Laura was formerly hearing in her room pre Master Set.  Tim doesn't have a TV between his speaks but does have an equipmemt rack.

Wall of sound?  Niagra Falls qualify?  Images are now more full blown and fleshed out with more vibrancy where as before they were smaller, more confined and center stage distant.  And his stage is much larger, if you didn't understand me.  His mid range is up in level (sounded a little malnourished before to me).  His sound system cooks, MUCH better than before!  On one recording above all the others, Time Out (on some fabulous pressing), I turned to Tim and said that's the best sound I've heard today.  Wanna amend that to the best sound I've heard on any day.  It was that good.  I was just too mind blown at the time to say so.

There is a foreshortening of Tim's depth of field, however.  And things seemed more lateral than 3D.  I just didn't care (don't think Tim does either).  Too much good was coming at me.  Definition and detail were amazing.  Sounded like my head was in the canisters of Joe Morello's drum kit.  I could hear the drumskin stretch.  And Desmond's alto had much more character than I ever thought possible.  The midrange of Tim's speakers was really more alive and present now.  I think/guess the near wall placement was responsible for supporting, even amplifying it better.  The sound overall was more even and dynamic.

I remain cool with my speaker placement.  My room is much smaller, so are my speaks, and my musical tastes run more all over the place.  I'm kinda partial to on location recordings, too, and faithfulness is important to me.

Timmy also identified an area of reflection on his ceiling and treated it.  Timmy done good.  Could be I'm hearing like what Laura is hearing?  Hope so.  Pretty awesome.

[jimdgoulding]

Amended the above for more accuracy and honesty.  No life left in this thread?   No appreciation of subjectivity?