Still Amazes me

Speaker postioning can have such a profound effect on the overall sound presentation and finished article, plus it costs zip just your time and methodical dismissiveness
I've spent some time this weekend rearranging the listening room, basically making it 2 foot wider, mainly for astectic reasons, yet its had a profound effect on the sonic characteristics of the system (I knew it would change, but not to the degree its shown ).
In essence its given me another 18 inches of width , thus enabling me to more the right hand speaker outwards.
Anyone who's been to Wm's has usually commented on the odd speaker placement, one speaker (left) 5 inches further in than the other, while the toe in is 30 or so degrees greater on the left speaker most odd looking but great sounding.
I must say this is entirely due to Merlin and Tact's first visit where he measured the room and found the .4m/s deviation from the right speaker.
Anyway, after moving the room about, obviously the sound was going to be off, I wasn't prepared for how off it was
Image and stage sat in the right corner just above the speaker, bass from high on the Left hand speaker, general disjointediness and coherently in coherent
Well after a relitively short time spent pratting about (still points have other bonuses as well as Isolation mucho ease of speaker movement )
I ended up with the right speaker 6 inches more forward the the left, and very little toe in, where as the left is massively toe'd across, to look at them you'd laugh, to hear them is grin forming, when the do slot into place it all just 'clicks', and it sounds so right, so what I'm saying is, have a play about (awalys mark you start point though), its free and the results can be impressive what ever kit you run Wm

 

Good stuff WM

By starnge coincidence, this weekend my new sofa and chair turned up, totally changing many aspects of the system. Fortunately for me, all changes were beneficial ,but it never ceases to amaze me how little attention many people pay to getting the room right in the first place.

I take it you removed that enormous reflection panel on the right side? Another recommendation would be to replace the hard venetian blind on the left with either a fabric one, or better still curtains. Then treat the left side first reflection and you should be able to point both speakers in the right direction - providing you with more direct sound and a more accurate portrayal

 

Excellent WM. I shall look forward to my next visit.

I wondered why we hadn't heard from you this weekend.

 

When I got the Superspikes, I also played a bit with speaker positioning, particullarly the right speaker was toed-out a bit and that enoyed me, I am an everything symetrical kind of guy, so when I put it straight, the stage colapsed and I could hear all the sound "directly" from the speakers...

I had to put it back about 1 cm toe-out and the stage is again wider than the speakers, deep and well focused... :MILD:

 

I'm with you here. Symmetry is the ideal. For one thing, when one speaker is toed out to a different degree than the other - which may be necessary for the reasons discussed - the dispersion characteristics of the drivers result in a difference in the character of the treble heard from each speaker.

This may be of more concern to your cat than yourself but does go to illustrate some the difficulties we have with our 'perfect' hi-fis in imperfect rooms - and that's apart from the more obvious difficulties with bass/room interaction.

 

I doubt 1 cm will make that much difference regarding room reflections versus direct sound balance, after all the EAII's tweeters are quite small 3/4", so must have good dispersion...

Actually I heard the same effect in a friends house, and he has the speakers in the long wall, miles from side walls...

As long as the first reflections are tammed, room interaction is unavoidable sitting 3 meters away, and does add some ambience...

 

Of course, smaller tweeters will have a wider dispersion pattern at a given frquency.

The crucial thing in 'eliminating' the room reflection is to have the speakers at least 1 metre (approx) away from the rear and side walls. I can't remember how many milli-seconds this equates to but psychologically, a delay of at least this amount will allow the listener to ignore the sound that comes from the walls as it arrives significantly later at the ears.

 

My speakers are about 1.5 meters from the rear wall and 70 cms from the side walls, but first reflections are taken care of, particularly the right side, where I have a bookshelf...

 

My understanding was that the brain assimilates any early reflections (within 30ms or a distance of 30ft) into the original signal. Anything over 30ft becomes a distinct echo.

Far more important IMO is the effect on frequency characteristics of those reflections caused by the surfaces involved. What Tact for instance are saying, is that the reflections arriving at the listening seat cause tonal abherrations because of both the effects of room modes and additionally both the off axis behavior of the drive unit and the surfaces of the listening room.

 

Tact is trying to sell their stuff, wich I have nothing against, but many systems work fine before, or without Tact...

You do have reflections in live music events too...

 

Antonio, do you want to reflect the reflections recorded into the source material ?

 

Good point Voodoo.

The difference basically is that normal setups give you the relective energy of your listeing room, the Tact attempts to give you that of the original recordings.

Now depending on the recording, the Tact aproach may rob you of the kinetic energy the mastering engineer assumes the listening room will provide. On natural recordings however, as I often say the Tact gives you a "we are there" sensation rather than a "they are here" presentation.

 

My understanding was that if the wall reflections are at least 3ms behind (about 1 metre further travel) the person will perceive the frequency response to be free of them. This is important because if you then correct for these, you would perceive the 'corrected' sound as inaccurate (if the 3ms theory is true).

Can't be sure though as I haven't done the empirical research. Still, there does seem to be a difference in perception as the speakers are moved to about 1 metre.

Interestingly, I had a discussion with the 'Layered Sound' inventor in which I questioned the ability of NXT panels to be able to hold their own when used in conjunction with high quality moving coil units, even at 5dB down. I was concerned both with their frequency response abherations and their slow rate of decay. He said that the reflected (ambient) sound in concert halls is by its nature 'dirty' (ie. not consistent frequency wise) and slow to decay. That's why he thought the layered approach worked so well.

There's always been disagreement about this, with some people preferring direct/reflected speakers (eg. Bose 901 or the new Beolab 5), others preferring a direct approach and some now going for the TACT approach.

 

Interesting, though I would imagine somewhat at odds with the haas effect

The Haas Effect states that the human brain has the wonderful ability to integrate sounds that arrive at the ear up to around 35-50 milliseconds. After that, instead of being perceived by the brain as part of the original sound, such late reflections would be heard as an echo, reverberation or an addition to it. This causes ear brain confusion and loss of clarity in the sound.

If we are talking about the timbral effects, then I would worry about any reflection being subject to a different off axis spectral response along with additional colouration from the wall.

It is worth also bearing in mind that with speakers placed one meter from the rear wall, the reflection of the back wave will cause cancellation in the mid bass. And that IS where the Tact is a winner

 

Very interesting WM,

I think I need to invite you guys around for a bake-off and to help me set up my kit properly, too bad certain member(s) of the family won't go away for a day or so

Given the weight of the speakers, I can't experiment that easily. Also, do you find that what may be ideal for stereo may not be good for movies?

 

i just got home and tried arranging my speakers in a non symmetrical layout. it had sounded good previously, but it persistently sounded as though the vocals were slightly off centre. i have a lightly odd shaped listening room, which though fairly generous in size, has a 1 metre by 1 metre incursion into what is otherwise fairly rectangular room (about 20' by 15') by towing the speaker nearest to the incursion, it has had an immediate and striking effect. don't know why i didn't think of it sooner, but thanks wm....

 

I dont have a choice, do I...

Anyway, try listening to music in an overdamped room, not nice...

Also, most recordings are closed miked, so they dont record many reflections, but live music has them, so I guess it will sound better with some, even if not original, as long as the room is reasonable...

 

Nice 1 WM!Lets see how long it is before ur larks get shifted around again! After adding a static stage isolation platform to my amp a couple of weeks ago it gave a massive dose of bass weight which meant i had to move the m53s virtually in the middle of the room to avoid any annoying basss humps Cant realy be dealing with that as my bedroom is quite small. I tihink the Tanoys that im waiting for will be alot easier to position, when i dem'd em the salesman jst plonked em down with no effort whatsoever and tehy still sounded superb. Think they have a bigger "sweet spot" than the missions which need very careful positioning.

Ultra