Open Baffle Experience

I switched to OB speakers (Emerald Physics) a while ago, and I don't think I could ever go back to a box speaker.

They need lots of room to breathe and placement can be tricky, but they sound absolutely glorious when you get them dialed in. Anyone who tells you differently is talking out of their ass.

The best sound I’ve ever heard to date was the Nola Grand Reference open-back dynamic towers driven by top ARC electronics. You can say whatever you want about OB designs, but that sound will live with me forever, and if it’s wrong I don’t wanna be right. Just sayin’. Also, if you pluck an acoustic guitar in open space it seems to me the sound that travels backwards will be at least somewhat out of phase kinda like a dipole driver, and a non-dipole speaker greatly misses or greatly diminishes the backward sound projection that is projected by an actual instrument yet could be captured in a good recording. Could be wrong, but this makes intuitive sense to me.

I've used B&W 804S speakers with their passive crossovers, then went active with digital xo, then into DIY boxed and eventually open baffle. Of course I do measurements for design work. System has now 2 sealed subs to 80Hz, 18" OB midbasses in H panel, and tweeter and midrange sitting above on a much slimmer panel. My tweeter is Beyma TPL-150H, which is actually the same one Spatial Audio uses on their X3 and X4, and I used to use it in a closed box and now open in the back. In fact, when I first ventured into OB I followed the back-to-front symmetry mantra and used a back waveguide like the one it has on the front and eventually realized it sounded as well without it so the back horn was removed (like Spatial does). The TPL is directly driven from Yamamoto 45-type SET...so much definition yet sweetness. The tweeter and midranges sound better to me in OB than boxed - same drivers - however I can easily compensate for the lower frequency decay in the mids, which is a natural phenomenon from the physics of drivers in OB. With passive XO this is trickier to get good results.

There were comments about wide panels. Of course wide panels are needed to support the lower end. However for midranges the wide panel is an issue: above the dipole peak the response is all over the place, especially noticeable at varying angles from the center. Narrow baffles allow reaching higher without this issue, to the point some people use baffleless (been there and came back). Crossing over before the dipole peak is preferred. Spatial Audio, to keep the example above, doesn't do this. Never heard one, but tend to think this would be audible.

Midbass is where I'm still not sure. OB definitely has more definition. However, even using 18" midbasses the sense of impact is much lighter than sealed. Maybe it's because I'm using a Faital driver that is not designed for OB and has low Qts, or because my room can't accommodate speakers 6 feet away from the front wall. I'm contemplating getting 15" Acoustic Elegance LO15, designed for OB, or a slot-loaded open baffle design that apparently conveys more impact while keeping the definition of OB. TBD.

For subs I experimented a bit, exchanged with Danny Richie at GR Research, who developed OB subs with Rythmik, and concluded my room wasn't suitable for such subs. I'm getting two additional sealed Rythmik kits to have 4 sealed subs.

Erik, I remember you at DIY Audio, so you probably have the skills and have fun building stuff. Would encourage you to do so, learn and listen for yourself. I have learnt some "laws" that are commonly accepted in audio fora that turned out not to be audible to me.

Have fun!

I’ve read some things in this thread that don’t jibe with my experience. I’ve had great box speakers that didn’t sound boxy. I now have Spatial Audio M3 Sapphires that are not forward and not harsh. I’ve driven them with a class d 2Cherry, an Orchard Audio GaN class d Stereo Ultra and a Wells class a/ b biased to 15 Watts class a… the speakers completely disappear with all 3 amps. 

Im pretty sure there is no “better” in term of hearing… there is just preference…at any rate, open baffles are not inherently better or worse but it is absolutely possible to get very musical sound from them. 
 

"i agree for 100% , the open baffle desigh is made for folk who is looking for something unsual , The speaker bulders using old idea like new , Nothing magic . Depend of baffle size , sound wave from front cone meet wave from back and kill each other, The best open baffle is infinity size baffle. For size 20-25" you did not get  low base, If you dont care about listen as is, If not --get sub , NO BENEFIT

Placebo effect"  

This shows a mis understandng of open baffle.   If drivers were facing each other and fired toward each other, we clearly have cancellation.  An open baffle fires forward Sound waves and they move forward.  When the rear waves fire out of the rear, they are not directly battling the front wave causing cancellation.  Ralph had the right idea.  The rear waves take time to bounce off of rear or side walls and end up coming forward firing in the same direction and reinforcing the front wave, the front and rear waves do not meet head to head causing cancelation.  What you get is a delayed effect for much of the frequency causing a spatial effect, which I assume is why a certain speaker company chose that name.  The real challenge is moving enough air at low frequencies to produce satisfying bass.which can be done.