Open Baffle Epiphany!

[davidro]

I really like this setup. Would you recommend some bracing inside the cabs?

 

[dnewma04]

It probably wouldn't hurt on the front baffle. Since there won't be much pressure exerted on the rest, it may not be necessary.

 

[davidro]

Thanks.

Well less is more really.

 

[valvenator]

davidro, you mentioned that "The cabs are bottom-ported and the port is pretty large - more of a void really"
Just out of curiosity, since the cabs are raised off the ground, have you tried covering the ports to see if that makes any difference?

 

[davidro]

I haven't really. Maybe I'll give that a go since I've gone semi OB'd.

What would be the anticipated effects?

 

[valvenator]

Not sure, but since most OB's have the baffles planted firmly on the ground maybe a different, hopefully better bass response?, or maybe not.
I'm new to this site. Running across this thread is what (re)peaked my interest in hi-fi. I'd really like to take a shot at open baffle in the near future and I'm just trying to gather information myself as to the do's and don'ts of OB design.

 

[PastTechFan]

....I'd really like to take a shot at open baffle in the near future and I'm just trying to gather information myself as to the do's and don'ts of OB design.

Also check out Audio Circle. There's a whole "circle" on Open Baffle:

http://www.audiocircle.com/index.php?board=90.0

(Hope it's OK with AK to link to other audio site.) :scratch2:

 

[smccrary]

Some crude OBs that I threw together to see what the fuss was about.

Full range vintage Grundig 5x7s. They are L/R of my Motorola 3 channel Console pull. The bass channel is currently hooked to a BPC Panasonic 10" vented box from a cheap HT system.

Holy Cannolini! These things produce 4x the sound of my Minimus 7s at the same volume level. Clear and detailed.

I see a full-on OB project in my future.

Would like to stay in the full range arena for the main drivers with some sort of bass augmentation.

 

[rogerfederer]

smccrary,

looks interesting. what is your theory on the diamond shaped aperture? sort of karlson cabinet-esque.

 

[Vaughn]

My guess is it was easier to cut than an oval

 

[PastTechFan]

Nice work! I like the symmetry, right down to the alternating planes of the fasteners. I wonder if you're maybe getting a little benefit from the diamond cutouts. A bit of slot-loading?

(Heck, I can't even cut circles properly yet, let alone ovals.) My OB maiden effort is posted in DIY.

http://www.audiokarma.org/forums/showthread.php?t=588445

Don't laugh! They really sound GOOD!!.

 

[smccrary]

For sure quicker and easier to cut diamonds than ovals. May keep it in mind for the future.

Any one need several pairs of Acoustic Suspension speakers….?

 

[Jim Shearer]

Not sure, but since most OB's have the baffles planted firmly on the ground maybe a different, hopefully better bass response?, or maybe not.
I'm new to this site. Running across this thread is what (re)peaked my interest in hi-fi. I'd really like to take a shot at open baffle in the near future and I'm just trying to gather information myself as to the do's and don'ts of OB design.

If you haven't been there yet, check out Martin King's site;
http://www.quarter-wave.com/OBs/OB_Theory.html

There are at least two schools of thought on OB design: wide baffle & narrow baffle. Start with theory & modeling to avoid the worst pitfalls, then get on with the fun of building!

Cheers, Jim

 

[Larryl1]

Question about using a single h-frame

Gang, I built an h-frame sub using the Eminence Alpha 15. Will I be o.k with just using the one? I plan to drive it with a plate amp but my Denon PMA-757 has no pre-outs. Not sure about wiring that config. I,m also going to build 2 cornu spirals to try with the set-up. Thanks for any advise and this thread, I'm having a blast!

 

[Poultrygeist]

Gang, I built an h-frame sub using the Eminence Alpha 15. Will I be o.k with just using the one? I plan to drive it with a plate amp but my Denon PMA-757 has no pre-outs. Not sure about wiring that config. I,m also going to build 2 cornu spirals to try with the set-up. Thanks for any advise and this thread, I'm having a blast!

One can work if your room isn't too large but two are better.

Most plate amps have a pass through ( line out ) in which the signal is not affected by the crossover.

You can connect your source i.e. CDP, DAC etc to the plate amp's line in and then run RCA's from the line out of the plate amp to the PMA-757 which drives your main speakers.

 

[portnoy]

I've been thinking about trying open baffles for a while so I finally dipped my big toe in the other nite.

Thes speakers are from a magnavox console that I canned several years ago.

I really do like the way they sound. The Magnavox 15" drivers are a little light on the low end so I'm augmenting the low end with a couple of subs.

It's not really an apples to apples comparison though, the Magnavox mid and tweeters are a bit brighter and more forward than my Wharfedales W-70s. But I can definitely tell that the sound is less pinpoint directional from an enclosed speaker and the stereo imaging and sound-stage are noticeably improved.

I think I do need to think of the most efficient layout of the drivers so I can make something smaller in overall dimensions.

Cheers,
Wayne

 

[noise gate]

To me, and I assume many here Portnoy's speakers look way cool, just like many other open baffle cardboard prototypes. Like some of my own carboard / scrap plywood efforts.

I just have to ask, am I the only ones who's "spousal unit's" give looks of bewildered astonishment at the ragged edge of this hobby?

 

[Poultrygeist]

I'd like to see room dividers used as open baffles.

Would increase WAF if she picks the screen.

That way she gains ownership and becomes part of the solution rather than the problem.

 

[mhardy6647]

They look like decorator versions of Magneplanar Tympani 1s ;-)

 

[dnewma04]

It'd be the Bose Acoustimass cubes of the open baffle world. "you can point them anywhere!"