What are the unique challenges to making a "baffle-less" speaker?

[chazdrumzalot]

I was very intrigued to watch this video:

YouTube - ‪OPEN SPEAKERS - WITHOUT BAFFLE‬‏

Is there an added challenge to building a baffle-less speaker as opposed to an open baffle, apart from how to support the driver? Take, for example, the Beta 12LTA or something of that nature. Would it be possible to run it free-air, apply baffle step according to the width of the driver itself and get a balanced sound down to its natural rolloff point? Or would the result be considerably different?

One last somewhat related question: Does anyone feel that taking a high-sensitivity driver and applying 6db of BSC robs such a driver of some of its 'magic'?

[mashaffer]

I would think that one would need tremendously high Qts (which the 12LTS doesn't have) or gobs of xmax and a *$&^#4 load of EQ. Or better yet a nice sheet of plexiglass.

[Rudolf]

Originally Posted by chazdrumzalot

Is there an added challenge to building a baffle-less speaker as opposed to an open baffle, apart from how to support the driver?

Go to my downloads page and look for "How open baffles work". Chapter 3 talks about baffle-less-speakers, but you need to read chapters 1 + 2 before that to understand.

[borispm]

Try find a large PA woofer, say 15" or 18" and a smaller full range driver, say Tangband W4, and then use lots of equalization.

[chazdrumzalot]

Originally Posted by Rudolf

Go to my downloads page and look for "How open baffles work". Chapter 3 talks about baffle-less-speakers, but you need to read chapters 1 + 2 before that to understand.

Rudolf, thanks for the link. I'll read it right now.

I suppose MJK's mathcad could simulate a baffle-less speaker, couldn't it?

[flg]

Rudolf has excellent insights to learn. Also N.P. MJK, Stigerik, JohnK, S Linkwitz and many threads in the Multi-way catagory. Particularly, is flat not correct or what ever, etc.etc. Lots of reading, re-reading and understanding.
The latest, "Fin" published project thread is the ultimate in DIY sucsess in dipole/OB stuff to look foward to

[Rudolf]

Originally Posted by chazdrumzalot

I suppose MJK's mathcad could simulate a baffle-less speaker, couldn't it?

Well, up to a point. The problem: If you have (almost) no baffle, the radiation from the backside of the driver becomes a major contributor to the forward radiation. Above 2 kHz (just to throw in a rough number) the radiation from the backside is heavily influenced by resonances in the cavities between cone, basket, spider and magnet. Plain Thiele-Small parameters don't apply any longer.
In my latest experiments MJK's worksheet have been helpful in estimating SPL levels and EQ demands, but not for simulating the frequency response in any detail.

Rudolf

[Cyberschelm]

The latest, "Fin" published project thread is the ultimate in DIY sucsess in dipole/OB stuff to look foward to

Hello,

To which project are you referring to specifically flg?

Regards,

René

[greenvalve]

The less baffle, the more crossover and EQ. Pick your poison.

YouTube - ‪Vivaldi plays on baffleless Fostex 126en and GR Research SW-12-16FR direct servo subwoofers‬‏

[woody]

There may be another potitional problem with this. True Audio in there article on difraction loss discussed the ripples in frequency responce caused by different baffel shapes. I wonder if a speaker without a baffel would show the same ripple effect as speaker on a circular baffel with the speaker mounted in the center? The article has a lot more shapes.




True Audio TechTopics: Diffraction Loss