Open baffle with fullrange driver and bass support

[Godzilla]

Many of us have already figured out how incredibly good a simple open baffle system sounds. Just select your favorite full range driver and partner it with an appropriately setup helper woofer. Even add a helper tweeter if you like.

After building several box and back horn type speakers I’ve ended up with some variation of an open baffle as my main system and both my sons. My sons are 13 and 11 and listen to music often. They love their speakers! I love mine too. In fact, nowadays when I think about building another set of speakers it’s always on an open baffle. I just think about the driver combinations that might work well together.

For those of you who’ve enjoyed open baffle speakers, please post combinations of drivers you think have merit. I know opinions will vary but what remains constant is the fact that a simple plank of wood with the right combination of drivers sounds better than just about anything anyone can buy or build.

I will start:
Eminence Alpha 15 + Beta 12lta + ASD 1001 w/Dayton waveguide
Jamo buyout 15” (qts of .95) + Pioneer B20 + Piezo

[ra7]

Eminence Alpha 15 is the woofer to go with if you are starting out.

My favorite full range pairing is the Audio Nirvana 8". Dynamics, naturalness and simply incredible detail retrieval.

Generally, bigger drivers are better on OB. So, I can imagine the sound GodZilla must be getting!

I have to say that an active crossover+EQ is almost a must for OB.

[KCHANG]

I have been playing with FR drivers and OB speakers for so many years. I have many conventional FR or WR cone drivers, but at the end none of them got into my favorate OB system.

The best OB spearks, or perhaps the best speakers, I have built use B&G RD75 line source drivers from 200Hz up and two bass panels each having four 18" woofers (actually subwoofer drivers) in a vertical array.

Most people in this "Full-Range" forum do not put RD75 drivers in the "full-range" category and thus would never consider trying them. Also, a lot people just never had the chance to listen to the RD75 drivers. It is a pity, because no cone FR driver I have slapped on OB, or any FR cone driver in a box, a front horn, or BLH that I have listened to, has ever come close to the performance of these line-source drivers. Granted, one can get rather satisfactory sound out of a simple system of cone FR drivers on OB augmented with helper woofers. Nevertheless, on my own quest for the ultimate OB system, I have ended up with something different.

Cheers,

Kurt

[Godzilla]

Bohlender Graebener RD75 Planar Transducer

Those are expensive! Thanks Kurt!

ra7 it wouldn't surprise me if the Jamo buyouts I'm using on my sons system outperform the Alpha's... i'd even consider these as H-frame or OB candidates on the cheap... and would expect them to sound great too:

GRS 15PF-8 15" Paper Cone Foam Surround Woofer

These 15" drivers limited to 200hz and below always seem to sound great. I power them with a typical sub amp. I've found regardless of sensitivity (the Alphas i think are rated at 97 and the Jamos were rated at 90db per watt) you still need 100+ sub amps to get them up and running (don't buy the sub amps rated below 100 watts, i tried two from PE and felt they were not up to par). So a 15" or even an 18" woofer, regardless of sensitivity, should work well with a 100+ watt amp on an ob and deliver bass into the 20s or 30s with relative ease.

It's a beautiful thing to hear.

[marce]

Just putting togetehr my final set up after 2 years of playing, gonna be:
2 x Alphas a15 per side
1 x FE207
1 x FT17
U frame, to save room, marrage etc, prefer H frame though.

Going to drive them via an active crossover with an eclectic range of amps, doing the final wood bashing over the next week, then gonna get a new power amp for woofers, as I blew my Audiolab 8000A.
I have tried different variants with 1 A15 per side and FE106's, FT17 in or out etc, personaly I prefer the combination I am going with.

[sreten]

Hi,

Given : http://www.quarter-wave.com/OBs/OB_Design.pdf

The GRS 15" at 87dB/1W/1m should suit some classic low
efficiency 3" full range drivers, e.g. the B3S, or NS3's on
sale at Madisound, with a similar passive c/o to above.
(Rebating the rear cutout is mandatory to avoid a peak.)

Given your not BSCing the 3"'s senstivity will be a lot
higher than if you used them in typical small boxes.

Chuck in the Apex JR $1 supertweeter, L-padded
(Made by Audax, by far the best of the type...)
and possibly a 1st order series c/o at say 5-7KHz.

(So the overall c/o is parallel bass/mid, series mid/treble.)

That should be a killer system for the price and simplicity.
Though it will need a fair amount of juice to drive it,
and levels won't really approach big box levels.

rgds, sreten.

We don't have these sort of driver choices in Europe ....