[matevana]

Scott Hinson was asked to design a passive 3-way open baffle speaker using the new SB-Audience pro sound drivers for the DIY community. The documentation and listening notes make for an interesting read and is available here: https://www.madisoundspeakerstore.com/pdf/SB%20Audience%20OB3%20Open%20Baffle%20Kit.pdf

The kit is available through Madisound with or without completed crossovers: https://www.madisoundspeakerstore.com/open-baffle-speaker-kits/sb-audience-ob3-open-baffle-3-way-with-15-woofer/

The 15" woofer is purpose built for OB applications.

Thought this might be of interest...

[mresseguie]

Definitely of interest. Thank you for posting this.

[Jon L]

Looks interesting, but one aspect is disappointing.  The compression driver is 107db sensitive, midrange 98dB sensitive, bass driver 99dB sensitive, yet the end speaker is 85 dB sensitive.   

A smarter person than me could buy the kit without the passive crossover and use full dsp for crossover/room/phase correction 

[studiotech]

Looks interesting, but one aspect is disappointing.  The compression driver is 107db sensitive, midrange 98dB sensitive, bass driver 99dB sensitive, yet the end speaker is 85 dB sensitive.   

A smarter person than me could buy the kit without the passive crossover and use full dsp for crossover/room/phase correction 

Agreed.  If you're going thru the exercise to do an all passive OB, running dual woofers help offset some of the baffle and dipole loses.  I'd have tried dual 12" to see if the end result saved more of that mid/top efficiency.

Greg

[Bumpy]

Looks interesting, but one aspect is disappointing.  The compression driver is 107db sensitive, midrange 98dB sensitive, bass driver 99dB sensitive, yet the end speaker is 85 dB sensitive.   

A smarter person than me could buy the kit without the passive crossover and use full dsp for crossover/room/phase correction 

This is the penalty you pay for using drivers that need massive correction and complex crossovers to get them to sing evenly across the full frequency band. Those passive electronics make my head spin.

[JohnR]

Just spit out my chips. And lots of box speakers are 85 dB.

[Bumpy]

Everything makes a sonic difference.  Using all those xover parts on a speaker is a recipe for veiled sound.  This is the magic of full range drivers.....no xover.

You could get the 8 inch full range Lii drivers (fast 8 driver....$200 a pair plus shipping) and run them wide open on a two foot wide, four foot high baffle with one foot by 4 foot wings going straight back.  You would get around 50 cycles flat in room.  You solder your speaker wire directly to the voice coil wires.....eliminating the distortion of the speaker binding post and steel tab.  You could add the small or medium ESS AMT on top using a copper foil cap at around 15K.  This would add a little air.  Add some woofers (preferably powered by their own amp).....xover around 100hz.....and limit the lows to the Lii by adding a small super sounding cap to the input of the main amp or if using a tube amp that has coupling caps then replace the coupling caps with better sounding smaller values to do the same.  By limiting the response of the full range driver, you lower its distortion and you get more mid bass slam when running the larger woofers up higher.    i would use a separate baffle for the woofs and then time align them with the full range and optional tweeter.  This system will sound worlds better than all those non time aligned drivers on a baffle using a ton of xover parts.  In fact, such a system would blow your mind.  Purity of sound.

Of course, you could get more expensive full range drivers and get even better sound.  However, even this "entry level" full range driver is REALLY GOOD!  You must bypass the binding post on the speaker and hardwire and the speakers will need several hundred hours of hard playing to do their magic.

Agree with most of what you say. But whizzers come with their own weaknesses so if you are moving towards fitting a tweeter then why persist with a midrange incorporating a whizzer?

[Ric Schultz]

The full range will be run wide open in the example.....the (optional) tweeter is just a "supertweeter".  Of course, there are lots of possibilities.  Life is infinite.  Enjoy the moment.  It is the only one we have.  Blessings to all.

[nicoch]

Looks interesting, but one aspect is disappointing.  The compression driver is 107db sensitive, midrange 98dB sensitive, bass driver 99dB sensitive, yet the end speaker is 85 dB sensitive.   

A smarter person than me could buy the kit without the passive crossover and use full dsp for crossover/room/phase correction 

yep is what I tell to Scott on fb but he  dont want understand