Forums - Print Page

Forums
https://www.decware.com/cgi-bin/yabb22/YaBB.pl
SPEAKER FORUMS >> Betsy Open Baffle >> The cool Australian open baffle
https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1588025375

Message started by Randy in Caintuck on 04/27/20 at 23:09:35

Title: The cool Australian open baffle
Post by Randy in Caintuck on 04/27/20 at 23:09:35

As I was sitting in my listening chair a couple of evenings ago, a "blast from the past" flashed into my mind .....

The original idea to start building open baffle speakers was hatched several years ago when I was a member of the (now defunct) Hawthorne Audio forum. There were a lot of DIY guys who posted to that forum and there were some really cool designs that showed up there.

I thought that it would be interesting to some of the Decware forum readers to learn where the original idea for the "Betsy baffle" came from.

One of the posters to the Hawthorne forum was a gent from Australia and he built a pair of open baffles from some massive slabs of a native Australian hardwood (I don't remember the name of the wood).

I was so smitten by the photos of his speakers that I decided to build something similar using plywood.

What a disaster that was .....

The Australian gent was even kind enough to post the dimensions of his speakers, but his massive slabs of hardwood did not "translate" well at all into "plywood copies" .....

Since I was still pretty much of a "hillbilly wood butcher", attempting to make something from big slabs of hardwood was way beyond my pay grade, so I started messing around with various sizes and shapes of plywood baffles ..... and the "Betsy baffles" were born .....

OK ..... OK ..... I know that the suspense is killing the readers of this post, so here are some photos of the original Australian baffles and the specs that were kindly provided.

Enjoy !!!

I don't remember the name of the Australian gent, but I owe him a huge debt of gratitude and hope that he is still enjoying this fine looking pair of open baffles .....

Happy listening,
Randy

Title: Re: The cool Australian open baffle
Post by MrDerrick on 04/28/20 at 00:00:12

Are those field coil drivers?

Title: Re: The cool Australian open baffle
Post by 4krow on 04/29/20 at 07:18:17

Nope. Those are coaxial drivers. The wires coming off of the driver(s) goes to the crossover sitting on the carpet behind the Open Baffle.

Title: Re: The cool Australian open baffle
Post by rayd on 04/29/20 at 09:41:11

Quote:

I don't remember the name of the Australian gent, but I owe him a huge debt of gratitude and hope that he is still enjoying this fine looking pair of open baffles .....

Hi Randy, was that nice gentleman Alf? I remember he was also a member here and he also was a preacher.

Title: Re: The cool Australian open baffle
Post by Randy in Caintuck on 04/29/20 at 16:07:27

Hi rayd,

Nope ..... it wasn't Alf.
I remember Alf very well as a regular contributor to the Hawthorne forum.
He had several very interesting projects that he shared with us ..... but these speakers were not one of them .....

I have gone back through all of the stuff I saved from that time period and it appears that the name of the builder was the one thing I did not save .....

Best wishes,
Randy

Title: Re: The cool Australian open baffle
Post by oztayls on 07/02/20 at 02:20:56

Hopefully, that gent will pop up here one day. Those OBs were made from slabs of Jarrah (Eucalyptus marginata), quite an expensive timber these days. Often used for upmarket outdoor furniture and decking due to its durability. You need some serious tools to make things from Jarrah as its very dense.

I'm considering either Jarrah or Victorian Ash (Also known as Tasmanian Oak) for my own OB project. Ash is 1/3 the price and stains beautifully to look like Jarrah. As I don't have a jointer and a big planer, I could buy a kitchen benchtop which comes in a 2400x600x33mm size, all nicely dressed and ready to cut! My son-in-law works for a kitchen manufacturer, so maybe I could even get hold of some offcuts if I'm lucky. Would 33mm be thick enough for a project of these approximate dimensions?

Title: Re: The cool Australian open baffle
Post by Randy in Caintuck on 07/02/20 at 04:59:43

Hi oztayls,

Yep ..... I couldn't remember the type of wood, but it was indeed Jarrah ...

The kitchen benchtop you are thinking about would be about 2 feet wide x 8 feet long (if my conversion software is correct) and about 1.3" thick.
That should give you enough to make a pair of baffles.

By all means, please share a photo or two of your project when it is finished.

Best wishes,
Randy

Title: Re: The cool Australian open baffle
Post by oztayls on 07/02/20 at 05:24:19

We live in wine country here, Hunter Valley in NSW, so barrels are easily obtained. I was eyeing off the wine barrel in our outside BBQ area and thinking mmm, mmmm, mmmmm. That could be a fun possibility too! All the staves are nicely curved and fitted already, although I'm thinking they would have to be glued up pretty quickly before they spring in all directions and no longer fit together!

Title: Re: The cool Australian open baffle
Post by oztayls on 07/02/20 at 05:35:33

I noticed that the drivers are not flush-fitted in many cases. Steve's are recessed and yours Randy, protrude at the front. Does it not matter much to flush-mount them?

Title: Re: The cool Australian open baffle
Post by oztayls on 07/02/20 at 06:34:51

While I wait for my Lii drivers to arrive from China (it could take a while!), I can start to get some equipment together. I bought one of those Jasper router circle jigs this morning, but now I have to find a 1/4" cutter bit for it. It will have to be extra long to cut through 33mm (1.3") and none of my bits will come close to doing the job. I'd be grateful for any tips for making these deep cuts for the drivers in hardwood and choosing a suitable bit.

Title: Re: The cool Australian open baffle
Post by Randy in Caintuck on 07/02/20 at 15:56:17

Hi oztayls,

The baffles that I offer are 3/4" thick.
I decided that flush mounting was not practical in a baffle of this thickness and that is why they are surface mounted.
As to the sonic effect, everything makes a difference, but I am happy with the sound of the baffles that I am making.

In thicker baffles such as the ones Decware offers and the ones you will be making, flush mounting makes perfect sense.

You should be able to find a suitable router bit online for your project.
To make my baffles, I cut the initial opening with a jigsaw and then use a top bearing router bit and a template for the finished opening.

Best wishes,
Randy

Title: Re: The cool Australian open baffle
Post by 4krow on 07/02/20 at 17:54:08

So many times, I misread a post, read it again, and laugh. What I read was that you cut the hole with a jigsaw, then I missed the TEMPLATE being used, and instead visualized a rough hole being copied by a bearing bit. I am still laughing at myself.