[tino84]

Hi,

I'd wanna try something like these

http://i194.photobucket.com/albums/z26/oneinchsidehop/open%20baffle/Open-Baffle-w-zenith.jpg

obviously in Ob 

I know bass near wall will be attenuate, is there something else to take care of? anybody tried something like these?

thanks

[nickd]

The 'Golden Rule" for OB designs is 3' from the back wall. You might get them to sound OK with a digital crossover or EQ but placement of OB drivers closer than 3' to the back wall will cause problems that are hard if not impossible to correct.

I would stick with a well designed box based speaker if you don't have the rear space. They can "disappear" and cast a huge soundstage too. You might be happier in the long run.

[mcgsxr]

Agree that more space is better, but one way to mitigage the issues is to toe in the baffle.  That changes the effect of the close wall.

In the end it is better to have 2-3 feet behind the baffles, but angling the baffles can help in situations you cannot find the space.

[tino84]

thank you for your tips, I'm reading something about wall-dip and Allison's theory to see what could be done.

mcgsxr, do you know a ratio between angles and front panel?

[mcgsxr]

I'd love to help you, but am purely a subjective guy so my experimentation with OB is largely driven by what I hear.

Toe in changes both rear reflection, and front response so moving them around is key.

I'd start with 20-30 degrees and see what you think.  I found toe in made the center image rock stable, even when walking outside the sweet spot.

I was around 40 degrees, and 2 feet from my back wall - but I had corner loaded the system too, so it was all experimentation at the time.

[zmyrna]

near wall OB is a no no for mid and high frequency.
you can make bass work though.
see lampizator'e elegant OB bass solution using bookshelves.

http://lampizator.eu/SPEAKERS/PROJECTS/P12/opoen%20baffle%20alnico%20speakers%20project%2012.html

at an angle or corner loading

[scorpion]

Good Lord, why do I have to live to see this.
Bass is away from walls and other frequencies do benifit from wall non occurrance.

/Erling

[tino84]

thnaks to all

zmyrna, I don't think that would be a good choice for me 

still searching a solution to take Ob in little space

[InfernoSTi]

I find the distance helps with clarity...the timing of the front wave with the reflected wave either adds "fullness" or it creates "fuzziness" to the sound.  The toe in helps but so does the distance from the wall.

One possible solution might be to use absorption (or perhaps diffusion) on the front wall behind and between the two speakers.  That might really help address the issues from being too near the front wall.

John

[scorpion]

Well, in fact you can experiment with side walls, but front/back wall ought to be 1 meter away, about.

/Erling

[tino84]

and what about a thing like these seen here on audiocircle ( with only 2 woofer to the side instead of 4)

http://ripole.dyndns.org/images/modelle/BMC%20200%20BB%20450sch.png

or something like these, with woofer used vertically

http://farm3.static.flickr.com/2588/4108487102_a552629bf1_o.jpg

what's  good and bad with these option?

[Rudolf]

and what about a thing like these seen here on audiocircle ( with only 2 woofer to the side instead of 4)
http://ripole.dyndns.org/images/modelle/BMC%20200%20BB%20450sch.png

Such Ripoles are recommended to have at least 40 cm between the back opening and the next wall. If you calculate about 40 cm depth for their housing, you are almost at those 3 feet for their front plane.

[tino84]

Such Ripoles are recommended to have at least 40 cm between the back opening and the next wall.

and it's a good thing for me  because using this solution I will have 1mt for right and about 2mt for left speakers from the wall.

the problem is the other wall, because on the other side I got a little wall, about 60cm. to clarify with an image

http://oi42.tinypic.com/2wrozs3.jpg

so I will have the front of a woofer directly near to a wall, how this will matter?

http://oi40.tinypic.com/imrps8.jpg

so, this is the old speaker, but room and position will be the same  , will I solve something with woofer on the side instead on the back?
thanks

[Rudolf]

Sorry tino84,

I don't see any reasonable OB solution for your situation. If it where me, I would look for higher directivity - probably waveguides.