I've read "put the front speakers so that the tweeter is at ear level". I have an Onkyo HT-SR800 and the front's have the tweeter in the middle, between two midrange cones. Usually the tweeter's are at the top, I think? So does the recommendation still hold for these, should I put them on 31" stands so that the tweeter is at ear level, or go with 24" stands so that the top cone is at ear level?

You might need to tilt them up if they are a classic MTM array so the tweeter fires at your ears when seated.

Take a seat in your chair, then have a friend hold a small mirror on the speaker baffle next to the tweeter. Get your friend to tilt (and maybe rotate) the speaker so that you can see yourself in the mirror...

Mark

Ah, so the recommendation that the tweeters are at ear level still holds for MTM arrays? If so, then I should just be able to get 29-30" stands that will place them directly at ear level without a need for tilting. Hopefully they won't look too stupid being way up in the air like that :-)

You might need to tilt them up if they are a classic MTM array so the tweeter fires at your ears when seated.

Take a seat in your chair, then have a friend hold a small mirror on the speaker baffle next to the tweeter. Get your friend to tilt (and maybe rotate) the speaker so that you can see yourself in the mirror...

Mark

Nice trick, that one will come in handy! :D

Ah, so the recommendation that the tweeters are at ear level still holds for MTM arrays?

This may cause some debate, but from the research I have done on the MTM (the D'Appolito 3/2 [3 driver, 2 way] speaker geometric design), it was always meant to run vertically. The design (crossover dependent) will control the vertical dispersion of the loudspeaker reducing early reflections off the floor and ceiling. If the tweeter is not at ear height, the speaker may sound a little dull, so why I suggested tilting.

I think three of these speakers look really cool below the screen if you can do this...

Nice trick, that one will come in handy!

Thanks :) It can be used to find first point reflections in a room as well...

Mark

I was under the impression that tilting a speaker such as a MTM can/will cause (lobing??)effects that could adversely affect the sound.

I was under the impression that tilting a speaker such as a MTM can/will cause (lobing??)effects that could adversely affect the sound.

I know that MTMs cause lobing if you listen even barely off axis.




Also, the mirror trick is the not-as-fun version of using a laser pointer and finding the angle that blinds the person sitting at the listening position. :D

Ah, so the recommendation that the tweeters are at ear level still holds for MTM arrays? If so, then I should just be able to get 29-30" stands that will place them directly at ear level without a need for tilting. Hopefully they won't look too stupid being way up in the air like that :-)


Just set them on top of a couple 30” high subs and it will work out perfect.

http://inlinethumb35.webshots.com/2978/2277191390068493142S600x600Q85.jpg (http://home-and-garden.webshots.com/photo/2277191390068493142DAkzPq)

I set things on top of my sub in the past, but not anymore... :( :eek: :D

I set things on top of my sub in the past, but not anymore... :( :eek: :D

The spike feet work good at keeping everything where it belongs.

The problem I have been having is with keeping the DVD’s on the bookshelf. :o

I know that MTMs cause lobing if you listen even barely off axis.

If vertically orientated, they should exhibit a dispersion pattern that is wider horizontally than vertically. The interesting point is that if you lay this type of speaker on its side, the opposite happens - it becomes narrow horizontally and wider vertically. The said "lobing" becomes problematic here as generally we sit side by side and there is a noticeable change in timbre if you are seated off axis, even when 3 identical speakers are used. The solution is of course to stand them all up, but WAF generally does not agree here especially around a direct view display. You have a little more acceptance with a front projection system.

Check the cover of JPK original Video Essentials and that vertical growth out of the TV...


Also, the mirror trick is the not-as-fun version of using a laser pointer and finding the angle that blinds the person sitting at the listening position. :D

A laser is useful (and for blinding anyone) to help find not only first point reflections, but also aligning the speaker to all fire at the main seating location. I even went so far as to make a grid "target" that is placed at seated ear height to help here...

Mark

CAVX, can you please explain more on how to properly find first reflection points.

I'll take a stab....

The method I've seen mentioned is for a helper to place a mirror on the wall between the seating position and the speaker(s) and move it around. Where you can see the speakers are the first reflection points.

I suppose a laser could be used to find the points by aiming it at the walls/ceiling to find where it reflects onto the speaker(s) - assuming the surfaces are adequate for that sort of thing.

I'll take a stab....

The method I've seen mentioned is for a helper to place a mirror on the wall between the seating position and the speaker(s) and move it around. Where you can see the speakers are the first reflection points.

I suppose a laser could be used to find the points by aiming it at the walls/ceiling to find where it reflects onto the speaker(s) - assuming the surfaces are adequate for that sort of thing.

Ok, Say I'm sitting in my listening position and the mirror is on the left wall, in the front of the room. Then I would start moving the mirror along the wall towards the back of the room until I can see the left speaker in the mirror? That would be a reflection point for the left speaker?

Or.. would I move the mirror along the left wall and when I see the right speaker in the mirror, that would be a reflection point for the right speaker? And vice versa.

CAVX, can you please explain more on how to properly find first reflection points.

I think whoaru99 has explained that pretty well.

When I did my first room, I used a laser and lined it up with the side edge of each LCR speaker encloser so that the beam was 90 degrees to the front baffle. In that room at the time, I had quite a bit of toe-in on the L and R speakers so the primary points were more towards the back of the room but on the opposite sides for the speaker being tested. I simply stuck treatments on the side and rear walls centering the treatment on the red dot, and it did make a huge difference - especially for dialogue intelligibility.

The problem is (I think) knowing where to stop, it is not that hard to over dampen a room...

Mark

Technically, anywhere you see a speaker in the mirror is a reflection point that will affect what sound travels to your ears.

Technically, anywhere you see a speaker in the mirror is a reflection point that will affect what sound travels to your ears.

so how wide of a mirror should be used?

I think whoaru99 has explained that pretty well.

When I did my first room, I used a laser and lined it up with the side edge of each LCR speaker encloser so that the beam was 90 degrees to the front baffle. In that room at the time, I had quite a bit of toe-in on the L and R speakers so the primary points were more towards the back of the room but on the opposite sides for the speaker being tested. I simply stuck treatments on the side and rear walls centering the treatment on the red dot, and it did make a huge difference - especially for dialogue intelligibility.

The problem is (I think) knowing where to stop, it is not that hard to over dampen a room...

Mark

thanks for your input, the inside edge or the outside edge of the cabinet?

Say I'm sitting in my listening positionI'm sitting in my listening position. I would start moving the mirror along the wall towards the back of the room until I can see the left speaker in the mirror? That would be a reflection point for the left speaker?Correct. Other first reflections for that speaker will be on the opposite wall, ceiling and floor. Those points can all be found doing the same mirror trick. I move the mirror along the left wall and when I see the right speaker in the mirror, that would be a reflection point for the right speaker?Also correct. Don't forget the reflection of the centre speaker. And vice versa.Exactly. Repeat the exercise for the wall on your right and look for the first reflection points of the three front speakers there.

Sanjay

thanks for your input, the inside edge or the outside edge of the cabinet?

When I did it, I used the top out side edge of L and R and centre for the centre speaker. At the time I knew virtually nothing of this, so it was simply as case of experimentation, but one that proved to be an improvement.

What I didn't really take into account is the width of the horizontal dispersion pattern which is closer to 60 degrees for my speakers. Ideally (I suppose) you would turn the laser to find the extreme points and cover the whole area, not just a very small centred area as I did...

Mark

thanks CAVX and sdurani, but one question.

Whats the max width of a mirror that should be used?

You could even use a hand held mirror. Your challenge is in hoping that your assistant can hold the mirror at the same hight as he/she moves it along the wall. Your going to find that the area that represents the first point is quite wide. Using a large mirror would simply be difficult to move around...

Lasers on tripods can be had for a low as $35 these days...

Mark