B&W 803S and side wall?

[specialized]

Hi there.. Im thinking to spread more speakers one from other.. Now they are like 2 - 2.5 meters between them, and im wondering what i'll get if i move one of the speakers one meter and they 'll be like 3,5 meters . But that way that speaker would be close to the side wall (like 10 cm from the side wall).

What is the negative efect of puting speaker next to the wall (sideway, from the back there is a lot of space)


Greetings

Darko

[emig5m]

Hi there.. Im thinking to spread more speakers one from other.. Now they are like 2 - 2.5 meters between them, and im wondering what i'll get if i move one of the speakers one meter and they 'll be like 3,5 meters . But that way that speaker would be close to the side wall (like 10 cm from the side wall).

What is the negative efect of puting speaker next to the wall (sideway, from the back there is a lot of space)


Greetings

Darko

I would say a negative effect is that the soundstage starts to become more boxed in and less 3D (suffocated). From my own personal experience, I'd rather have a speaker closer to the back wall than the side walls (if you can swap the system to a longer wall that is). If you're stuck on one wall or all the walls are the same length and you have to spread the speakers apart to get closer to having an equilateral triangle with the listening position, then autoroom eq could come in handy! :B I know this winter when I have the time I'm going to put my front end back on the longer wall....

[Horacio]

now wouldn't you be in the best position to answer that??? maybe try it out and decide for yourself, instead of going by someone's answer despite how informed that person is.

Trust your ears. It's your opinion that counts!

[specialized]

now wouldn't you be in the best position to answer that??? maybe try it out and decide for yourself, instead of going by someone's answer despite how informed that person is.

Trust your ears. It's your opinion that counts!

Best solution But i asked becouse it's a bit complicated becouse i dont have longer cables and i have to disconnect the amps and to move it on other side.. And that mean i have to move preamp as well, and after that maybe receiver So thats why asked and this weekend definitly i'll try I post the question becouse teoreticaly i know we should go away from the corner and i thought that side wall effect is less pronounced then back.. But i'll check and try


Darko

[pazu]

Hallo!

I've 803S too - 2,40 m between them, 1,00 m by the side wall, 0,55 m by the back one, as you can see on the photo.

In my opinion, we get the best sound with these loudspeakers - soundstage at the first - if they're not too much near by the side wall.

But I know that my room is not your room! So, please, tell us about your next tests.

:T

[specialized]

Hallo!

I've 803S too - 2,40 m between them, 1,00 m by the side wall, 0,55 m by the back one, as you can see on the photo.

In my opinion, we get the best sound with these loudspeakers - soundstage at the first - if they're not too much near by the side wall.

But I know that my room is not your room! So, please, tell us about your next tests.

:T

Now im on 2.8 meters between them, right speaker is very far from the side wall (there is table on half meter distance, and about 1 meter from the back wall..). Left speaker is about 1m from side wall and no back wall (it's on the door entrance ).. The sound is superb, but i have a bit problem becouse speaker a bit block the entrance in the room


Darko

[emig5m]

In my opinion, we get the best sound with these loudspeakers - soundstage at the first - if they're not too much near by the side wall.

Yup, my same experience. Sidewalls = bad.

[pazu]

Yup, my same experience. Sidewalls = bad.

Uhm... interesting!

I think the sidewalls are more problematic than back one because our 803S have no reflex tube on the rear (it's in front).

Are you agree?

[Horacio]

Uhm... interesting!

I think the sidewalls are more problematic than back one because our 803S have no reflex tube on the rear (it's in front).

Are you agree?

...mmm...maybe that's also a factor...

The two main things that come to mind when speaking of back and side wall distances are first reflections and excitation of modes/certain frequencies.

First reflections: two identical signals arriving at the brain within a 5 ms window (I think that was the figure) are processed as the same signal, but since they are delayed from each other we hear that as "fuzzy" vs. a spatial tip when the two signas arrive with a time difference larger that 5 ms. In our rooms, time difference = difference between direct sound (from speaker to your ears) and reflected sound (speaker bounces on wall, bounces to your ear). First reflections are most critical as 2nd reflections are much reduced in strength (audibility). So the difference between direct path and pah for each first reflection point is key. That's why a carpetd area where the floor first reflection point is, is generally strongly recommended and generally yields good results. The ceiling is more difficult to treat. Then your front and side walls, which is what this thread was about...sorry this is getting so long! Sooo, at least theoretically, the closer you get to the side wall, the more likely you are to get soundstage and imageing worsened. But other factors also come into play (many factors...and if you think this is long already...let me stop here!). Is the first reflection on a flat hard surface, a bookcase, a sofa, or what? That will change the strength of the reflection, and hence its audibility. If the speakers are toed in then the reflection is reduced, as the radiation pattern isn't circular bu no means, especially at higher frequencies. Which brings us back to the above question regarding the reflex tube: thinking of soundawaves as rays that can be reflected is good modelling for higher frequencies, but not for bass, so can't really tell if the reflex tube position will have an effect from this point of view. I tend to think it shouldn't.

Then the excitation. A driver is placed to excite at resonance frequency those frequencies for which 1/4 wavelength = distance from the driver to the room boundary (ie: floor, ceiling, and side walls). The floor distance is a known value to the designer and thus has been accounted for - not an issue. The ceiling is so far away that is not an issue either. The front and side walls are a different story. If you happen to place your drivers at a distance equal to 1/4 wavelength of a problematic frequency (problematic for the room frequency rersponse), then you might hear it.

How much does all this matter? Not much if you can't hear it!!! I enjoy understanding how this works, but doesn't mean my room sounds better than anybody else's because of that. That's way I was stongly suggesting to try it out. :B

BTW, don't want to misrepresent myself as a specialist in this subject. I just read a couple books on it and couple it with my mechanical engineering background (sound is mechanics after all). I hope it helps!! :T

[specialized]

[BTW, don't want to misrepresent myself as a specialist in this subject. I just read a couple books on it and couple it with my mechanical engineering background (sound is mechanics after all). I hope it helps!! :T[/QUOTE]


Nice teoryl.. We should talk more about this way of improving the sound.. And while i know and i agreed with u it's still my living room and if i send the pictures (no carpet, glass tables, a lot of windows .. ) , im sure i'll get negative feedback

In the future i plan to have room just for listening and i'll definitly treat every detail. Still this is a good subject and hope to continue, becouse its much cheaper improvement then just pay extra hardware..


greetings

Darko

[Horacio]

Still this is a good subject and hope to continue, becouse its much cheaper improvement then just pay extra hardware..

you bet it's cheaper!
You don't have to have a dedicated room to apply this. I don't. My system is in the living room, and have 3 kids between 9 and 6, and a wife who hates audio. So lot's of constraints, yet the improvement is noticeable. So much so that even my wife noted the improvement. A vdedicated room, of course gives you a lot more freedom, but you can still apply the concepts and get creative to conceal functionality.

Understanding accoustics has been a VERY good use of my time, in my opinion. YMMV, of course. Highly recommended. :T