Big open baffle project

[hugobors]

All open baffle expert, welcome

I have a dream : build a big 3way open bafle system


Why 3 way? because from experience, it's more difficult to crossover in the 100-5000Hz region.

- Bass-100Hz : 2 or 4 15" in lml or llmll configuration

- 100-5000Hz : one 7" to 10"

- Tweeter or coax with medium

On something like 50cm (20") wide panel.

Active filter with eq for bassloss and eventualy for medium (ideally not but with a 50cm wide baffle, I think it's difficult for the medium to reach 100Hz, but maybe with a high Qts....)

But which driver to use, what's for you the best unit for each frequency band?

And for the medium, I don't like too much the bicone fullrange for a directivity question, but do you think a coax can do a very good job in this configuration???

All is open, just put your opinion....

Thanks
Hugues

[owen]

For bass duties, a large pro driver, for mid duties a nice fostex, and for tweeter duties, well pick your high efficiency poison..

That would do the job nicely


Owen

[hugobors]

Do you think a fostex can do good bass at good SPL on a50cm wide baffle???

Any other suggestions???

[adason]

hi Hugues,

I think Owen meant the Fostex for mids only.

I am not an open baffle expert, but I would not consider 50 cm baffle as big.

Two woofers per side are always better than one. Depends on spl you want and what woofers are you going to use.

Otherwise its a great project.

ed

[preiter]

I'd look at existing OB projects to see what drivers they use.

Martin King has an OB project on his site with a lowther driver and 15" bass augmentation. http://www.quarter-wave.com/Project07/Project07.html

The is, of course the Phoenix and the Orion from Linzwitz's site. http://www.linkwitzlab.com/

The NaO Mini is similar to what you want. http://www.musicanddesign.com/NaOMini.html

The Visaton B200 is also very popular in OB.

[Rudolf]

Hugues,
IMHO you shouldn´t cling to a 100 Hz crossover frequency that much. If you x-over at 200-300 Hz, a 50 cm baffle will easily be large enough to stay above the baffle step for the mid driver. So no eq needed there.
The Jordan JX 92S would probably be an excellent candidate for medium/high duties.

I don´t see any advantage in a "lml or llmll configuration". llm would be my choice for this application everyday. Keeping the mid driver at the upper edge of the baffle would allow for the smoothest frequency response.

Rudolf

[Magnetar]

Here is a quad amped (horn loaded below 50 cycles) open baffle with 21" woofers, JBL 2123J mids and Heil air motion transformer treble.

I have since replaced the treble with Beyma CP 380M compression drivers loaded in 18 sound elipsiod horns

Old Thread-

[el`Ol]

The Omnes Audio L8 would be a nice driver from 100Hz on, and with the L8spec, Spectrumaudio`s version with copper polepiece, you would get along without a supertweeter if you EQed away the rising response.

[hugobors]

What about using 2 or 4 Eminence Alpha15???? After simulation on thorsten excel sheet, it seems it not need EQ for a response to about 35Hz (-3dB) on a 600mm baffle for a sensitivity around 92 dB so with two 95dB, Four : 98dB......

Suggestions???

[MuaDibb]

Look at the Bastanis website, this is similar to what you are looking at. From what I have researched people seem to think it is a modified Eminence Beta LT which runs to about 10,000Hz where it naturally rolls off and gets picked up by the tweet. It sits on top of a sub and looks quite nice. I have thought of building something similar.

www.bastanis.com
www.baulsaudio.com