Baffled by NO Baffle?

[dickwest]

There is an open baffle thread at the link below, and this linked message begins the sub set of messages that demonstrate what can be done to pursue a concept/idea to its logical? conclusion -- if you have enough $$:

http://www.diyaudio.com/forums/multi-way/142015-my-open-baffle-dipole-beyma-tpl-150-a-42.html#post1996017

You can see how his baffle-less speaker system evolved. It uses 8 channels of amplification and DSP xovers and signal processing. Not a project for the average person, but interesting nonetheless.

And, he claims, all in the pursuit of increased realism in sound reproduction.

[Face]

Re: Baffled by NO Baffle?

Wouldn't those chains rattle?

[benchtester]

Re: Baffled by NO Baffle?

Wouldn't those chains rattle?

Yes, but the chain rattling is remarkably realistic. :rolleyes:



Seriously, one could align the links and tension them so the wouldn't. I would have gone with aircraft cable and turn buckles to pursue this concept.

But I can't believe that the edge of a driver is the ideal shape; at least put a ring with a radius around it.

[dickwest]

Re: Baffled by NO Baffle?

If you bother to read the thread you will understand the issue of chain rattle is a non-issue even though some contributors did seem to prefer sash or venetian blind cord.

Progress occurs best with an open mind .

[Face]

Re: Baffled by NO Baffle?

Sorry, I didn't get a chance to read the thread yet.

I will say though, those chains remind me of a torture device or something in the bedroom. :D

[Guest]

Re: Baffled by NO Baffle?

Seems the movement of the midwoofers would cause some sort of effects... and "compensated for" cancellation effects would produce less than "natural sound"........ IMHO

[Pete Schumacher]

Re: Baffled by NO Baffle?

Seems the movement of the midwoofers would cause some sort of effects... and "compensated for" cancellation effects would produce less than "natural sound"........ IMHO

Inertial movements by the drivers will be manifested as response aberrations. Minimal movement will produce minimal response ripples. Not having panel resonances to deal with seems a reasonable trade off.

I'll echo benchtester's sentiment. There is nothing "ideal" about a naked driver as a baffle. Sure wish I could see the thread. It's blocked here at work.

[Guest]

Re: Baffled by NO Baffle?

Inertial movements by the drivers will be manifested as response aberrations. Minimal movement will produce minimal response ripples. Not having panel resonances to deal with seems a reasonable trade off.

I'll echo benchtester's sentiment. There is nothing "ideal" about a naked driver as a baffle. Sure wish I could see the thread. It's blocked here at work.

True... I'd rather deal with baffle resonances, and avoid the other problems. Small sculpted/damped "baffles" would seem more reasonable to me... but it would be fun to play with if one had measurement equipment.

This would be fun in designing a 4-way...

[dickwest]

Re: Baffled by NO Baffle?

Dig into the thread with an open mind and you will find measurements and an examination of the typical issues you guys are raising. I had them as well. The portion of the thread given over to STIG's experiments is revolutionary, not amateurish. It can be a learning experience, although his results seem to fly in the face of conventional "wisdom".

[gowa]

Re: Baffled by NO Baffle?

I think this video will explain better.

http://www.youtube.com/watch?v=8ffl3KxY3g4

[diy speaker guy]

Re: Baffled by NO Baffle?

There's nothing new or revolutionary here. There's been much discussion lately about using thin baffles for good power response. It's been suggested that each driver should be on a baffle no wider than 2.2x driver diameter if decent power response is desired. No baffle is just the logical extension of thin baffle.

As long as each driver is operating under the first dipole peak, there is NO diffraction to worry about (except maybe for the tweeter since it's impossible to make it small enough to completely eliminate diffraction). This approach is terribly inefficient but it works and should provide excellent sound quality.

I probably would not have used chains to hold it all together, but that's just me. Also, for the bass section I would have used multiple 18's with no baffle instead of the H frame, just to keep with the no baffle theme.

I didn't read the thread, but just a quick glance at the picture is worth a thousand words. Nothing new here. It's not popular for obvious reasons (awful efficiency, multiple amps and filters required) but it works. I'd have done my own no baffle dipole system already if it weren't so complex and expensive.

[dickwest]

Re: Baffled by NO Baffle?

. . . a quick glance at the picture is worth a thousand words. Nothing new here. It's not popular for obvious reasons (awful efficiency, multiple amps and filters required) but it works. I'd have done my own no baffle dipole system already if it weren't so complex and expensive.

Well said. I also would like to try such a system -- when/if I win the lottery. But, it has been interesting to follow Stig's evolution of his no baffle system. He is demonstrating his approach does work.

[brianpowers27]

Re: Baffled by NO Baffle?

There's nothing new or revolutionary here. There's been much discussion lately about using thin baffles for good power response. It's been suggested that each driver should be on a baffle no wider than 2.2x driver diameter if decent power response is desired. No baffle is just the logical extension of thin baffle.

As long as each driver is operating under the first dipole peak, there is NO diffraction to worry about (except maybe for the tweeter since it's impossible to make it small enough to completely eliminate diffraction). This approach is terribly inefficient but it works and should provide excellent sound quality.

I probably would not have used chains to hold it all together, but that's just me. Also, for the bass section I would have used multiple 18's with no baffle instead of the H frame, just to keep with the no baffle theme.

All very true and good information. I would love to read through the thread but at 45 pages, it just isn't going to happen. Highlights are always appreciated.

That would take a lot of 18s.... Did you see the posted specs on that Beyma 21" woofer? 60mm xmax (peak to peak).

Has anyone considered using the Dayton 15" IB subs for OB duty? I bet two in paralell would do the trick for efficiency and xmax,qtx and fs are all favorable.

[Pete Schumacher]

Re: Baffled by NO Baffle?

All very true and good information. I would love to read through the thread but at 45 pages, it just isn't going to happen. Highlights are always appreciated.

That would take a lot of 18s.... Did you see the posted specs on that Beyma 21" woofer? 60mm xmax (peak to peak).

Has anyone considered using the Dayton 15" IB subs for OB duty? I bet two in paralell would do the trick for efficiency and xmax,qtx and fs are all favorable.

A pair of RSS390HF would be better, don't you think? Better motor design equals lower distortion and more flexible cut off points. If they're driven actively, then EQ isn't an issue and Qts means nothing. If crossed passively, then modifications of Q via series resistance and low cutoff accomplish the goal.

Have you seen the performance of the AESpeakers IB15 using the Lambda motor? :eek:

AE IB15 distortion

[brianpowers27]

Re: Baffled by NO Baffle?

A pair of RSS390HF would be better, don't you think? Better motor design equals lower distortion and more flexible cut off points. If they're driven actively, then EQ isn't an issue and Qts means nothing. If crossed passively, then modifications of Q via series resistance and low cutoff accomplish the goal.

Have you seen the performance of the AESpeakers IB15 using the Lambda motor? :eek:

AE IB15 distortion

I assumed that the motor was the same between the rss subs and the IB sub.

The AE products look great but the cost puts it outside of my realistic purchases for quite some time. THey have a dipole 15 that looks great for the job.