Integrating dipole woofer with baffles

[Nuuk]

While I am still looking for woofers, I am thinking of how I will integrate some dipole woofers with my current open baffle speakers which are Goodmans 201's in flat baffles about 4 feet by 2 feet.

I don't have enough space in my room to build some H baffles like Chops; and even placing a W baffle to the side of the main baffles is difficult due to space/furniture.

So I wondered if there would be a problem placing the W baffles immediately behind the main baffles with the bass 'firing' through an aperture in the main baffles.





So, do you think that this would be a problem? As far as I can see, the main baffle should reduce the cancelleation and actually give a bit more bass.



And how about adding those extra 'bits' coloured brown? Would that improve airflow and possibly quality of bass.

[Volenti]

I can't see any problem with that, I ended up using 2 18'' pro audio drivers in a W baffle that doubles as a stand for my TV, we have ways of intergrating these things

I don't know weather the extra 'bits' would make an improvement but they wouldn't hurt anything.

[sreten]

Nothing seems to be wrong with the idea in principle.

Your added sections should help in my opinion, but
you'll need good filtering to control the W resonance.

sreten.

[Nuuk]

Your added sections should help in my opinion, but
you'll need good filtering to control the W resonance.

Could you please explain that a bit more?

[Ilianh]

Here Linkwitz talk about resonances in folded frame open baffles.

http://www.linkwitzlab.com/models.htm#C

and he shows how to apply the corrections

[Rudolf]

Could you please explain that a bit more?

This might be helpful too:
http://f18.parsimony.net/forum31999/messages/58929.htm

[Nuuk]

the notch filter compensates for the "box" resonance of the dipole. If you build a "W"-dipole that just fits a 12" driver, you will need to compensate for an approx. 300 Hz peak.

I will be using my dipole woofers up to around 80Hz. Does that mean that I won't suffer the resonance?

[Rudolf]

I will be using my dipole woofers up to around 80Hz. Does that mean that I won't suffer the resonance?

The question is: Does it hurt?
If you use an active lowpass filter with at least 12dB/oct. , you will have almost 2 oct. (24dB) to the resonance. That should be sufficient to make it nonaudible.

[LineSource]

Around the crossover point, it seems putting the woofer directly in back of the main speaker would create some cancelation of the main panel's back wave and hence create more 4 PI radiation and potentially negative room effects.

[Nuuk]

If you use an active lowpass filter with at least 12dB/oct. , you will have almost 2 oct. (24dB) to the resonance. That should be sufficient to make it nonaudible.

Thanks Rudolf, I was going to use an active crossover.

Around the crossover point, it seems putting the woofer directly in back of the main speaker would create some cancelation of the main panel's back wave and hence create more 4 PI radiation and potentially negative room effects.

And thanks Linesource. It seems that this job isn't quite so straight-forward as I first thought. I guess it is the old problem of trying to have deeper bass in what is a 'smaller' listening room. Perhaps this means removing some furniture; thank goodness I am single