Open Baffle OR Baffle-less ?

[KSTR]

😕
Sorry KSTR i don't follow... 1 or 2 ft. listening distance ?

Yep. Best is to use two woofer stereo, close behind your back, 90° angled.
Think of a monster bass headphone. But it should be located quite below ear level to avoid reflections of front speaker signals. I've also seen one guy using a OB woofer firing down above his head. Same idea.

 

[CharlieLaub]

It's nice to see the discussion this morning with people finally saying if you want low bass, it's going to be big. Big baffle, big drivers, big box or big EQ. That's physics. And OB is going to be the biggest because of the rear wave cancellation.

For the lowest frequencies, e.g. with a dipole subwoofer, you can fold the baffle to create a U-frame or similar structure. This helps you increase the 'baffle dimension' to a practical value without making a physically wide and tall system. The drawback in this approach is that you will create a resonance from the duct or line that is formed, however, there are ways to mitigate this. When the length is not too long, the resonance will be around 200 Hz. Making it longer will decrease the line self-resonance but also improves the low-end output capabilities. Making the line cross-section larger (e.g. several times Sd) will reduce the Q of the resonance so that it can be flattened with EQ. An H-frame will make front and rear resonances the same. Together, a modestly to medium sized H-frame with cross sectional area A=3*Sd can work well for dipole bass and will be easy to match to a (planar) OB woofer below 80-100Hz. This is the approach that I am taking in my next system build.

 

[Eldam]

...At the price of less sensivity (-2 dB) than a U-Frame and a little higher F3... so need even more EQ (bass boost)! (with the same length but with a classic large width bafle (non folded) my understanding is you have + 3 dB efficienty over a H-Frame, just + 1 dB over the U-Frame ! The H-frame may have a lower Fs though !

http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf

 

[JonBocani]

Yep. Best is to use two woofer stereo, close behind your back, 90° angled.
Think of a monster bass headphone. But it should be located quite below ear level to avoid reflections of front speaker signals. I've also seen one guy using a OB woofer firing down above his head. Same idea.

we're close to car audio, SPL drag race, etc... 🙂

 

[Baffless]

Maybe i should reduce a bit my coffee consumption, but hey hey, here's another thread for your DIYolic pleasure, and mine. 😛


So, let's start by the beginning:

about the Sound/Noise that go through the Cone... - diyAudio

Then, the ''no-box-is-better'' started to show up (as expected), then i tried the 18FH500 baffleless ('cause i couldnt do better tonight) and now i'm asking:

IF the produced bandwith fills my needs (80hz+ as of now)... Is any added baffle is useful/wanted, or the ''baffleless'' or ''minimalistic baffle'' is a approach worth considering ?

I'm simply thinking about reducing as possible the unwanted reflections & resonnances that i felt/heard (that comes usually from an enclosure in the 80-500hz region) and also to reduce the baffle material and size of the ''enclosure''

I think baffle less is better than open baffle with some large baffle. Just make simple prototype with drivers suspended on strings like this EQ them for perfect impulse response and you will immediately feel the difference. Polar response will be quite good also. The sound too