Loudspeaker Placement


#1

Hey guys, I am writing for some advice.

My system setup is P10->DirectStream Sr->Musical Fidelity Primo->BHK300-Kef Blade 2. Using bridge 2 as source. No subs (yet).

My room is 21,5 feet long, 14,8 feet wide and 9.8 feet high.

I have been working on speaker placement. The speakers are about 4.5 feet from the rear wall, 3.3 from each the side walls, and 8.2 feet apart. Using very little toe in (the off axis response and the dispersion of the speakers are very good)

I can get a beautiful and locked center image. The phantom center channel is right there, and the sound comes from behind the speakers.

But, when I play recordings that concentrate some instruments on one channel (for example, drums on the left and piano on the right), the speaker become foward sounding and suddenly I am aware of their presence in the room. And all of the time, the “center channel” keeps itself locked and behind the speakers.

Where should I begin tweaking to get better imaging?


#2

First and most importantly, your speakers should be on the long wall, not the short one. This will stop the problem. Why we naturally think speakers should be deep in the room on the short wall always fascinated me… we all just thing think this is the correct thing to do.

Notice what you have already done… you toed the speakers inward. The reason they sound better is not because the speaker is “firing at you” but because you are limiting the damage the side walls are causing. As the speakers try to fire sideways, those soundwaves bounce off the side walls and given the delay (echo) is so short, they interfere with your brain’s ability to interpret locality. By toeing in, you are lessening the amount of energy bouncing from those side walls.

When you put your speakers on the long wall, the time delay from bouncing off the sides is extended… delay starts becoming echo… now another psycho-acoustic effect comes into play, the Haas Effect… this actually helps your brain localize information from the main source, the speakers (which contain information from the recording etc. etc…)

With your speakers on the long wall, you may actually feel they sound better pointing straight out because you will (may) want the longer-delayed reflections because of the improved imaging this will cause. (Also look up “stochastic interference”… the introduction of noise to enhance perception… the delayed sound waves are a type of noise.)

If you must put your speakers on the short wall, try placing sound absorbing material on the side walls… just assume there is a mirror on the side walls… so from your chair, where the mirror allows you to see the speaker, put a panel there. You can get really cool stuff from a guitar/music store that sells recording equipment.

I learned all of this from owning Magnepans… a dipole radiator. The rear firing sound bounces off the back, then side walls and creates a longer and mixed time delay that fills the room with “noise” and from the Haas Effect, makes scary good imaging. It is addicting. Now the lower frequecies can get cancelled out and that is a whole other problem…

Peace
Bruce in Philly


#3

Hey Bruce,

thank you for your inputs. I have limited options in putting the speakers on the long wall. Also, being them positioned on the short wall, it may benefit my listening position, as it will be farther from the rear wall (actually, it is now about 4 feet away from the rear wall).

I will try some absorption on the side walls. Also thinking in moving the speakers closer to each other.


#4

The lack of imaging you speak of is almost always dependent upon the recording process . If you get great imaging on one recording and not so great on another,it is not your speakers/setup at fault…but rather the recordings were mixed/mastered that way. I notice this myself on a lot of older recordings from the 50’s, 60’s, and 70’s. With recordings that are mastered with great imaging and soundstaging,it never happens. I would not fret over it,its just the way it is.


#5

Closer has problems too… when you go closer, the radiated energy beam from the left speaker is increased into your right ear and visa versa. Bob Carver and Paul McGowan recognized this interference and developed technologies to limit it. Carver had their Sonic Holography unit that fired out of phase information from the left into the right channel to try and counter this interference. I owned one of these units and it was cool as hell… spooooky real imaging…oooooo… but did damage to the music while it enhanced imaging… more of a science experiment than a tool for music.

My general rule for placement is simple. Start with the speakers about 3 feet from the rear wall. Move the speakers as far out wide (to the left and right) as you can without creating a “hole in the middle”… then stop. Wide is good. Then start moving the speakers back to the back wall (or farther out but three feet usually does it)… listen for the bass on this one. Then add absorption to the side walls. Then lastly, try adding scattering/diffusion (not absorption) to the rear walls (Haas Effect again).

Then spend the rest of your life moving the speakers one inch at a time… toe in, left/right/back/out… absorption/diffusion rear side walls, all while tweaking the imaging.

Other lessons learned: speakers close together is bad thing. Speakers against the back wall is a bad thing. Speakers above your head? Well I am moving.

Read about Paul Klipch and his philosophies… very interesting… his most famous design put the speakers in the far corners! This used the walls as an amplifier… but far left and right was his thing. When he was challenged that he never modified his designs or philosophies, he said something like “they never changed the laws of physics”. (The Klipschorn is the only speaker in the world that has been in continuous production, relatively unchanged, for over 70 years. )

Since I am on a roll… What is not talked about is height, and floor/ceiling interactions. Generally I try to absorb the reflections… carpet…ceiling is tough. … this also ties to why headphones are not really that great at imaging. Did you know you hear with your skull? This is how you can localize sounds above you… predator or prey in the trees. Think of a sound source is say 45 degrees above and in front of you, the sound wave passes around your head into your ears. If the source is to the left or right of you, your ear/brain hears both a volume difference and a time delay differcence. If the sound is to the left of you, your left hear hears a louder sound and your right ear hears a softer sound with slight time delay. But what about that sound above? Well the sound wave hits your skull and is transferred to your inner ear via that fat thick skull of yours… that transmission through this bone results in a bizzare frequency response with big notches. The location of these notches (peaks and vallies of volume) is interpreted by your brain as height information. Cool. Two ears and a skull can interpret location in three dimensions. Headphones are missing this aspect and therefore can;t do true imaging.

Peace
Bruce in Philly


#6

I agree with Mark. Right now, I’m listening to a recording where the trumpet and bass are dead in the center, the drums are right channel and the sax is left. If you walk up to the speakers, the drums and sax are strictly limited to those channels. I like to start my placement process with a mono recording, then go from there for the best bass.


#7

Hey Ron,

My point is more about forward/ backward sounding then position. That is, the “center channel” is always behind the speakers. But when an instrument is all off one side, it becomes in front of the speaker. Do you also experiment this effect?

Bruce, should I take my wife’s word on how stubborn I am, I would not localize a predator above me even in a million years!


#8

Great thread, I love learning from those who have spent time in the trenches. Thanks!


#9

When the center image is perfect, the speakers seem like they’re not even there. When an instrument is rigidly one channel, you become aware of that speaker, hence it’s “forward” of the speaker. That’s my flu-addled wild ass guess.


#10

You described exactly what I am hearing. And my headache is finding out if this is a normal effect of the stereo imaging, or if I should tweak more my speaker positioning.


#11

I agree, Mark. I’ve also noted that some of the earlier recordings would clamp an instrument on the left and another on the right for the “stereo effect”. That caused me to fret over speaker placement until I noted that other good recordings were nicely spread out behind the speakers so I concluded my speaker placement was fine.

I also agree with Brunce-in-philly about the long wall placement, if possible. Before I bought my Dunlavys, I visited John (fascinating guy) at his factory in Colorado Springs. He was an advocate of the long wall also and had his demo area set up that way and made me a believer.


#12

If you are hearing a similar effect across recordings, then it is your system… something is wrong.

A system “perfectly” set up will sound totally different with different recordings. Commonality is an indicator of a problem.

Peace
Bruce In Philly


#13

John Dunlavy… I came within a hair of buying his IVs… “Ruler Flat” was his mantra.

Peace
Bruce in Philly


#14

I definitely hear differences on recordings. For example: Beatles stereo recordings up to Sgt Peppers fell way exagerated, with the voice pinned down to one speaker, and all instruments on the other.

Now, Coltrane recordings sound way much more balanced, sometimes dead center, sometimes with the voices half-way between center and speaker.

On Led Zep (yes, I am eccletic), I get a bit of everything. Some bad recordings, some bettered by the 1994 remix, some not at all.


#15

Those Beatle records you heard like that were put out by mistake… or more accurately without Sir George Martin’s involvement. I have a German pressing of Rubber Soul like that… curious but awful.

The knucklehead that mastered them tried to put them out “like they were recorded”. GM had said that this intent while laudable, is dead wrong. He always mixed the master to deal with the realities of pressing and playback. Those were intended to be mono recordings and required a final mastering mix. Further they were purposefully recorded “hot” (bright) because every time they bounced from track to track, they lost the top end. This all required throughtful mixing and EQ when mastering for print… and that included compensating for what was about to happen to the signal in the transfers to pressing etc… No, with those old recordings, you can’t just “release faithful to the tape”… faithful was intentionally not good sounding.

Further, these recordings, intended as mono releases had to be artificially enhanced to be stereo. If you put headphones on… they make you want to barf with all those weird phasy crap going on. As an aside… I watched a YouTube vid interview with Geoff Emerick who noted the Sgt Peppers recent re-master was awful. He said the only good version was the mono version. They mucked it up ackording to him… he said something like “someone came up to me as said they were surprised there was a cowbell on there. There was but we worked hard to make it NOT SOUND like a cowbell” Geoff was angry.

Peace
Bruce in Philly


#16

Very interesting remarks. It also explains why my recordings sound so harsh and bright. My collection is mono for the first 2 albums, and stereo thereafter.

As a matter of fact, I am very pleased with the original stereo version of Sgt Peppers. Never heard the mono one. Will look for it. I also did not like the 50th anniv edition. Sounds artificial to me.


#17

Everyone has different reactions to what they hear. I personally prefer the Giles Martin mixes to the original stereo versions. Has more realistic soundstage than the old multi mono tracks with voices left, guitars right etc. The mono versions sound so closed in! To each his own. i would love to see Giles work over some of the other albums.


#18

The mono is by far the best.


#19

Ok. I surrender. Just went out and bought the mono box collection. Will spin them this weekend.


#20

Please report back and let us know what you think. I find good mono remarkable for providing a sense of depth and realism one would not expect out of a single speaker.