What about Open baffles and line arrays.

[Forsman]

I’ve read pretty contradictious statements about OB line array. Many on this forum are praising the sound quality of OB Line Arrays. In different threads I can read that other people with well documented experiences are stating that OB line arrays is just a to complicated construction why better left alone.

Why I’m curious in this matter is because I’ve got 24 3½ in drivers and 50 small 1 in tweeters (Veco 32KC08-1). I’m going to build some sort of line array but I’m far from sure that I dare to go OB.

Is OB line array a safe way to go or is it a tricky and complicated path?

Kind regards
/Forsman

[trusound]

I am a huge proponent of OB... but only if you have the room.. IMO the room needed to pull off OB let alone a line array OB it paramount...

I always think to myself after seeing pictures of OB apllications were the speakers are close to both the back and side walls that there isn't any way that it could sound right..

You need the space to pull off OB

[juliopr]

Hello. Maybe I am not the best or the most expert, but, in my limited experience I believe that the use of so much drivers will require appropiate amplification and filtration(IMO active XO),which will provide the best control of those drivers. Also, the small radiating area will deliver limited bass response and the baffle area will affect the sound quality. I recently built an OB and used fewer drivers but bigger ones( 2x15", 1x6.5", 1x B&G NEO8) with active XO and Tri-amp. At this moment It is the best speaker I ever had and satisfies both quality and levels of listening. I wanted to have the soundstage and spaciousness of a planar magnetic or electrostatic, but with higher volume level and dynamism. The only worry I had was lack of bass due to the natural roll off but with the Eminence alpha 15 driver, I got plenty of bass. Maybe those 3.5" will be better on a boxed line array design. But that is only my humble opinion.

[Rudolf]

I don`t see any contradicting requirements between OB and line array. But of course the combined requirements will need more attention than OB or line array only.
In your possible application I see just one issue to take care of: If your crossover to the bass section is well above the Schroeder frequency of your room, your bass section should be a line array too. Below the Schroeder frequency you are free to apply any principle you want.

Rudolf

[LineArray]

Mostly agreeing to what Rudolf says,

i recommend this paper, unless you already know it.

http://www.systemsolutions.co.za/Tec...te%20Paper.pdf

For dipole operation you will need 1-1.5m of free space behind the speaker.

If you are willing to invest that space, you can go OB.

In my opinion the line array part itself is the more diffcult one,
since there are more concepts to line arrays than just simulating
a "true line source".

There are "constant beamwidth" concepts, bessel arrays, arrays
shaded with frequency and so on.

You also have to decide, if you want fullrange dipole operation,
which is what i prefer when going OB, or if you want your tweeters
to operate as monopole line source only.

Using a baffle, whch is taller that 2.2 x diameter of the drivers,
is a good thing to avoid lobing in the horizontal plane.

Linkwitz Lab - Loudspeaker Design


But with such a tall baffle, you will either need lots of EQ in the
deep bass or you will need a dedicated subwoofer - which is what
i recomend.

Linkwitzlab and Rudolfs page

Dipolplus

are good sites to have a start on the OB matter.

Kind regards

[StigErik]

I'm in the process of testing an OB line-array. Thread here:
Dipole line-array idea

[6.283]

Hi Oliver,

Originally Posted by LineArray

Using a baffle, whch is taller that 2.2 x diameter of the drivers,
is a good thing to avoid lobing in the horizontal plane.

taller => I guess you meant smaller (i.e. slimmer, narrower) ?

regards
Oliver

[LineArray]

Yes width <= 2.2 x diameter of driver.

English is not my mothertongue .

Linkwitz gives some hints on that.

[Forsman]

Originally Posted by trusound

I am a huge proponent of OB... but only if you have the room.. IMO the room needed to pull off OB let alone a line array OB it paramount...

You need the space to pull off OB

Unfortunately I have a rather small room.

Originally Posted by juliopr

Also, the small radiating area will deliver limited bass response and the baffle area will affect the sound quality.

Ok, I thought that a total sd of about 660 cm2 (almost the same area as a 12") was much but I understand that in an OB it isn’t.

Originally Posted by LineArray

Mostly agreeing to what Rudolf says,

i recommend this paper, unless you already know it.

http://www.systemsolutions.co.za/Tec...te%20Paper.pdf

For dipole operation you will need 1-1.5m of free space behind the speaker.

If you are willing to invest that space, you can go OB.

Thanks for the tips. Once again I see that you point out the importance of having the right room for the speaker.

Originally Posted by StigErik

I'm in the process of testing an OB line-array. Thread here:
Dipole line-array idea

I´m following your thread with great interest.

Thanks
/Forsman