Preparing the perfect listening room for 40.1

[A. E.]

Our new house is under construction, still have time to do best. By the way, the listening room is my study room and my wife has promised not to make fun of what ever I do in my room in favor of getting better sound.

I'm planning to use wood to give ceiling an attic shape to prevent standing waves, altough the room is on the ground floor. Height will be 2.40m in front and back, middle will be 3m (I'm not sure to leave the space empty or to fill with rockwool).

But there is another alternative: to separate listening and studying rooms by a double sided bookshelf by leaving a passage for me and bass reflexes.

Which alternative would you choose to get better soundstaging+imaging and tighter bass with 40.1's?

[A. E.]

[A. E.]

What do yo think of the final plan?

I had to give up wooden ceiling idea, since the windows are 280cm long.
Back and right side walls are made of bookshelves.
Room dimensions - 373cm X 570cm X h:300cm

Are they too close to each other to get a wide soundstage.

[Matti]

I do not know whether you are already familiar with this one, but if not you could get some help from here:

http://www.cardas.com/content.php?ar...ing=Room+Setup

Best,

Matti

[KT88]

Hello, A.E.

In your initial diagram, you show the speakers toed in (angled) toward your listening position, in the second diagram they are aimed straight ahead. You will most likely get a wider soundstage in the straight ahead position, just be sure they are not too far apart as this will breakup your center image. I always use the straight ahead set up with my Monitor 30's, and put the speakers the same distance apart as they are from my listening position. I find this gives the best balance between a solid center image and a naturally wide soundstage.

I hope this is helpful, enjoy your 40's and your new room!

[A. E.]

I do not know whether you are already familiar with this one, but if not you could get some help from here:

http://www.cardas.com/content.php?ar...ing=Room+Setup

Best,

Matti

Yes, I had used the Cardas' calculator to point out to speakers' place...

I'm not sure if I really need to leave that much empty room behind the speakers? Should I put some houseplants behind the speakers? or any diffuser like this one?
http://i299.photobucket.com/albums/m...Diffusor03.jpg

[A. E.]

Hello, A.E.

In your initial diagram, you show the speakers toed in (angled) toward your listening position, in the second diagram they are aimed straight ahead. You will most likely get a wider soundstage in the straight ahead position, just be sure they are not too far apart as this will breakup your center image. I always use the straight ahead set up with my Monitor 30's, and put the speakers the same distance apart as they are from my listening position. I find this gives the best balance between a solid center image and a naturally wide soundstage.

I hope this is helpful, enjoy your 40's and your new room!

Thank you, KT88

I think I'll find the right place by method of trial and error... I hope it will be around somewhere I have already calculated, so that I don't have to pull down the walls :-)

Do you think if they are too far apart? Is it ok to place them 1.67m apart?

[KT88]

Hello again, A.E.

That sounds like a bit under 6 feet, which is the distance I have my 30's apart. That seems about right, now see how things sound with your listening chair that same distance away from your speakers.

[honmanm]

Do you think if they are too far apart? Is it ok to place them 1.67m apart?

The apparent soundstage width varies with the angle at the apex of the "speakers and listener" triangle where you sit. You've drawn the classic "equilateral triangle of stereo" which is probably the best possible starting point. If you change to, for example, 2.5m apart and 2.5m from speaker to chair you will have the same soundstage width. What you will get is a change in the ratio of direct and reflected sound - the closer the speakers are to you, the smaller the contribution of the reflections within the room.

If you change the shape of the triangle, with more distance from you to the speakers than there is between them (narrower angle at the listening position), you will have a narrower soundstage but more "solid" central image. As KT88 said, pointing the "reference axis" of the speakers at you will have a similar effect. As I understand it the speakers are designed to measure as flat as possible on the reference axis; frequency response off-axis is not the same as high frequency sound waves are more directional and thus there is less to hear off-axis. So that give you two factors to play with: distance and angle.

The other thing to bear in mind here is that when a large speaker is placed close to you, there will be a greater difference in the distance from your ears to the 3 drive units of each speaker. I honestly don't know whether this is worth worrying about, though.

I'm gradually learning how much can be acheived by "trial and error" in speaker placement. After 20 years enjoying panel speakers (and tolerating their placement rules), it has come as a big surprise how much the perceived sound of my little Harbeths can be altered by changing their position and angle. At first this seemed to be a problem, but now it has become clear that this is a useful way to compensate for the limitations of the room and partnering equipment.

I had always thought that "slightly turned towards the listener" was the right way to set speakers up; however in this particular set of circumstances it has been necessary to angle the P3ESRs so that the reference axes cross just in front of the listening position. In your setup with the big speakers and book-lined room KT88's suggestion is probably the best... but don't be afraid to experiment.

[A. E.]

1. The apparent soundstage width varies with the angle at the apex of the "speakers and listener" triangle where you sit. You've drawn the classic "equilateral triangle of stereo" which is probably the best possible starting point. If you change to, for example, 2.5m apart and 2.5m from speaker to chair you will have the same soundstage width. What you will get is a change in the ratio of direct and reflected sound - the closer the speakers are to you, the smaller the contribution of the reflections within the room.
If you change the shape of the triangle, with more distance from you to the speakers than there is between them (narrower angle at the listening position), you will have a narrower soundstage but more "solid" central image. As KT88 said, pointing the "reference axis" of the speakers at you will have a similar effect. As I understand it the speakers are designed to measure as flat as possible on the reference axis; frequency response off-axis is not the same as high frequency sound waves are more directional and thus there is less to hear off-axis. So that give you two factors to play with: distance and angle.
2. The other thing to bear in mind here is that when a large speaker is placed close to you, there will be a greater difference in the distance from your ears to the 3 drive units of each speaker. I honestly don't know whether this is worth worrying about, though.
3. I'm gradually learning how much can be acheived by "trial and error" in speaker placement. After 20 years enjoying panel speakers (and tolerating their placement rules), it has come as a big surprise how much the perceived sound of my little Harbeths can be altered by changing their position and angle. At first this seemed to be a problem, but now it has become clear that this is a useful way to compensate for the limitations of the room and partnering equipment.
I had always thought that "slightly turned towards the listener" was the right way to set speakers up; however in this particular set of circumstances it has been necessary to angle the P3ESRs so that the reference axes cross just in front of the listening position. In your setup with the big speakers and book-lined room KT88's suggestion is probably the best... but don't be afraid to experiment.

Dear honmanm,

Thank you for your contributions.

1. Does “reflected sound” enhance or damage the holographic soundstage? Should I have curtain on the window side or glass closed cabinet door on the opposite side instead of open bookshelves ?

2. I think extremely different distance of drivers won’t cause a problem. Alan says: “It is impossible to hear the individual drive units...” and I had read somewhere that it was advised to place the Harbeth’s so close like wearing a headphone*. http://www.harbeth.co.uk/usergroup/s...2436#post24361

3. I accept to work on speaker placement later on, no problem. But I’m afraid of missing the opportunity for any acoustic treatment before building contractor finishes his job.

Do you think I need any treatment for ceiling, ground, left wall, front wall and the space behind the speakers?

Do you have an idea which is an unrealistic dream now, because of you can’t construct your room all over again.



* {Moderator's comment: To clarify, I think Alan said something like 'uniquely with Harbeth speakers you can listen to them in the super-nearfield like headphones (and you'd hear how good they are compared to other speakers)' not that you must listen that close!}

[A. E.]

whoops... did I say that?

Dear moderator, thank you for stopping me to start a bush-telegraph :-)

[honmanm]

I'm really guessing (hopefully educated guesses!) here as I'm very new to "box" speakers, but let's try anyway..

1. Does “reflected sound” enhance or damage the holographic soundstage? Should I have curtain on the window side or glass closed cabinet door on the opposite side instead of open bookshelves ?

A lot "depends"... it is the reflections that give one an idea of "space", however there may be a conflict between the spatial cues in the recording, and those that come from your own listening environment.

In a non-reflective environment ("acoustically dead") you hear what is on the recording with great accuracy but in the case of a studio recording it may not sound like people playing music in a room because you are hearing (very clearly) a mix of musicians recorded in a studio. So a lot depends on your taste...

Glass is definitely a bad idea, it is very reflective and also resonates. You don't have a lot of space, so a more "dead" environment is probably best.

3. I accept to work on speaker placement later on, no problem. But I’m afraid of missing the opportunity for any acoustic treatment before building contractor finishes his job.

Do you think I need any treatment for ceiling, ground, left wall, front wall and the space behind the speakers?

The bookshelves probably do most of what you need. You could put in heavy curtains around the walls behind the speakers and across the windows, or even have accoustic tiles behind the curtains.

Your floor should be solid and with a non-reflective surface (thick rug?). I can't say whether a sound-absorbing treatment on the ceiling would help, though.

But the above is just guesswork, I'm afraid.