Open Baffles for under $300

Poultrygeist · « **on:** 5 Dec 2011, 10:55 pm »

Wild Burro Audio Betsy's - $100 a pair
Alpha 15A - $130 a pair
Two 80 hz low pass XO - $34
Plywood - $26
Ikea cork placemats - $5

Rclark · « **Reply #1 on:** 5 Dec 2011, 11:06 pm »

When I first started looking at building a system, those were the first thing I looked at and almost pulled the trigger but ultimately the whizzer cone was a no go for me. I need a real tweeter.

Poultrygeist · « **Reply #2 on:** 5 Dec 2011, 11:15 pm »

Want a tweeter? Here's a cheapo Rat Shack horn tweeter that's an easy addition.

Poultrygeist · « **Reply #3 on:** 5 Dec 2011, 11:22 pm »

These horn tweets are said to be made by Fostex and the build quality is quite high. I changed the two caps to slightly different values and dampened the pod.

Poultrygeist · « **Reply #4 on:** 5 Dec 2011, 11:50 pm »

Cheap and cheerful source and bi-amplification for these Open Baffles:

Miniwatt S1 drives the Betsy's - $230 new

Denon AVR-1905 drives the Alpha's - $35 at garage sale

Rotel RCD-855 feeds analog signal to Miniwatt and digital to Denon - $50 at local thrift store

JLM · « **Reply #5 on:** 6 Dec 2011, 01:22 am »

I'd be hard pressed to not go slightly over budget and pick the Hawthorne Audio 10 inch or 15 inch Silver Iris coaxial drivers. Very efficient, use a very small baffle yet has solid bass, no whizzer, professional quality build (handles tons of power), and only $160 each. Not highly detailed, but good tone, and without fatigue. The 15 inchers go deeper, but leave a midrange dispersion gap with the much smaller tweeter.

For 5 - 6 times the money, the Sterling versions sound very similar but add detail.

Hawthorne even sells the pre-cut baffle/stands.

randytsuch · « **Reply #6 on:** 6 Dec 2011, 01:30 am »

I have wondered how the betsy's sound.

A while ago, on their diyaudio forum, Wild Burro said they are working on a field coil with Dave Slagle. I'm really interested to see how much they are going to be. Pretty sure it will be more than $300 though.

Randy

Poultrygeist · « **Reply #7 on:** 6 Dec 2011, 02:34 am »

How do they sound? Good enough to make me sell my Zu's.

randytsuch · « **Reply #8 on:** 6 Dec 2011, 02:49 am »

Quote from: Poultrygeist on 6 Dec 2011, 02:34 am

How do they sound? Good enough to make me sell my Zu's.

I was wondering what you had compared them to, must be pretty good then.

So, it looks like you are running the Betsy's and the tweeter wide open, just letting their natural roll off take care of things?
You just put a low pass filter on the woofer?

I would think being able to run the drivers with nothing between the amp and driver would be a big advantage.

Randy

JohnR · « **Reply #9 on:** 6 Dec 2011, 06:00 am »

Nice

Poultrygeist · « **Reply #10 on:** 6 Dec 2011, 12:04 pm »

Yes, I run the Betsy's wide open and there are no filters in the signal path other than the low pass XO that cuts the Alpha's at 80hz.

Here are some mods for the cheap and cheerful Radio Shack super tweeters. You can often find these tweets at flea markets for only a few bucks.

http://diyaudioprojects.com/Drivers/40-1310/40-1310.htm

Letitroll98 · « **Reply #11 on:** 6 Dec 2011, 02:08 pm »

Ab fab there Poultrygeist, a nominee for C&C of the year for sure. I wondered what the little shelf in pic 1 was until I scrolled to pic 2, thought it was a place to put your beer while listening or working.

I was looking at Wild Burro and the Betsy as well, could you describe the sound a bit? Perhaps as more of a fleshed out comparison to the Zu?

Poultrygeist · « **Reply #12 on:** 6 Dec 2011, 06:11 pm »

I thought the Zu's had a wonderfully expansive soundstage but not as large as these OB's. The Zu's could pinpoint better with a tad more detail but at the expense of width and depth which these puppies deliver in spades.

It is a revelation to hear OB's float notes in space with more air and openess than is possible from a box speaker. Vocals and instruments pop out at me and I didn't get that so much with the Zu's. The sweet spot is greater with the OB's but less pricise that with the Zu's.

The Zu's super tweets are better integrated than my Rat Shack home brews but to tell the truth there's not so much going on up there except cymbals.

The Zu's had lots of good strong bass but not the natural "bass in free air" sound that the Alphas produce. The Alphas make the best musical bass I've heard. They sound nothing like a plodding sub plus they play in stereo.

The advantage that comes with OB is that music sounds "live" and not from a box. With OB you're in the box ( your room ) with the music. Both speakers are very easy to listen to but the OB's are the more relaxing. I read somewhere that OB was less taxing on the brain. I don't know if that's true but I do know I listen to them more for enjoyment without a need to dissect what I'm hearing.

Poultrygeist · « **Reply #13 on:** 6 Dec 2011, 08:59 pm »

Maybe I should add a shelf on the front for my beer

SET Man · « **Reply #14 on:** 7 Dec 2011, 01:59 am »

Hey!

Pretty cool!

I like the idea of having the mid drive running full range.

As for the Rat Shack horn tweeters. I've heard many say that they are made by Fostex and I think it is true since some of the Rat Shack full range speakers were made by Fostex. Not to mention that those horn tweeter you have now look a lot like the current Fostex FT17H horn tweeter... I'm currently using a pair in my system as super tweeter.

I find OB speaker fascinating but just don't have time, money and space to try them.

BTW... I've heard that those Rat Shack tweeters might have a built in capacitor in them, not sure if this is true. But if is true than they are likely xover lower than you want for your main driver.

Take care,
Buddy

Poultrygeist · « **Reply #15 on:** 7 Dec 2011, 11:56 am »

Hi SET Man,

I changed the stock caps in the tweeters and now they're crossed above 10kHz. Thanks for looking.

cpmiller · « **Reply #16 on:** 19 Apr 2012, 02:26 pm »

Poultryeist,
I see you are bi-amping your Wild burro FR and sub. I just started listening to a set of BetseyK's and will also try adding subwoofer but am thinking about trying something like Martin King's passive 2-way (http://www.quarter-wave.com/OBs/OB_Design.pdf). Did you attempt that with the Betsey and Alpha or have you only run as bi-amp?

Chris

jk@home · « **Reply #17 on:** 22 Apr 2012, 11:36 am »

Has anyone compared an OB speaker of this quality (or slightly higher) against the entry level Magnepan MMG?

Right now I'm running a highly modded pair of MMGs, always wondered what I would gain or give up with cone OBs.

Poultrygeist · « **Reply #18 on:** 22 Apr 2012, 01:06 pm »

I've never tried passive crossovers with the Betsy/Alphas. I prefer bi-amping i.e. driving the Betsys with a low power SET while powering the Alphas with a high power solid state amp. My main OB system ( Tang Band W8-1808 over H-frame Alphas ) use dedicated Dayton APA 150 amps to drive the Alphas. The Daytons offer greater flexibility with their built in XO controls.

The cheap and cheerful Betsy/Alpha OB's offer better bass than the maggies I've heard and affords the option of using an inexpensive low power SET rather than an expensive megga watt solid state planar amp.

mungodrums · « **Reply #19 on:** 13 Apr 2015, 09:28 pm »

I am seriously considering a pair of Magnepan MMGs or a pair of Wild Burro Betsy's in mini me baffles with Audio 10 wooden phase plugs. I used to own the Magnepan MMGs. Don't have a lot of space to work with. I know that the betsy's don't require much power, low powered tube integrated etc. I know that the betsy's have less bass than the magnepans but assume they are more dynamic, how about the midrange and high end, especially with the phase plugs? Does the high end on the betsy's with phase plugs reach 20htz? Ger.