50% off to take Betsy where she's never been!

[pjanda1]

Pete,

Here's the deal. I think I'm out of BetsyK's in this batch (I hear a check is in the mail, so I'm not exactly sure). If you are willing to document the project somewhere new and visible, I'd be happy to let you in on the sale. But, I'd ship you a pair of drivers that have been lightly demo'd. They are essentially perfect (one has a little bugger around a mounting screw), but I figured I'd mention it in the full spirit of disclosure.

You can never start too many projects! Screwing speakers into those JE Labs baffles would be pretty easy, and it doesn't cost much more to ship four speakers than it does two. FWIW, long down my list of projects is to use the miniDSP parametric EQ function to experiment with notch filters. I'd then build an equivalent circuit with passive components, but it would sure be easier to not buy a big pile of parts.

Send me an email either way,

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[keantoken]

Hi. I sent an Email to Pjanda but it got rejected, presumably because the images were too large. I decided to post here instead.

Here are the pics of my current progress. The finished thing will be about 6 feet long, 3.5 feet high.







It's been great fun so far. Many trips have been made to town, after discovering a new tool was needed. I discovered how to make straight cuts with a table saw.

- keantoken

[freddi]

are those boards for an open baffle? BetsyK has a great cone

[keantoken]

Yes.

It turns out I can't get the nasty stain out of the middle board, but I'm more interested in functionality at this point.

My idea is to pack cloth behind it so it's a damped open baffle. Not sure what it'll do, but I had the idea and I'm gonna test it out.

- keantoken

[keantoken]

My Betsy's arrived today!!!

I've got one sitting upside down on top of a thin wood box stuffed with a towel... Rather inferiors enclosure, I know.

As expected, it sounds better than any speaker I've heard before. When I turn up the volume, it sounds the same as before - Just louder! Oh, the humanity! It's a nice change from the crappy, $2 speakers (okay, more like $80...) speakers I usually listen to.

Just amazing... I don't think I'll get tired of these anytime soon...

- keantoken

[adason]

I received my Betsy-WOW today.
Nice looking speakers. I could not resist and slapped it on the temporary ob. I measured fr response of fresh driver, just out of curiosity, with Holm Impulse.
On my baffle it starts at precisely 50Hz flat to about 700 Hz. There is weird looking dip between 700-800 Hz, (might have something to do with the width of the baffle?). Between 50 Hz and 700 Hz its exceptionally flat. Things are not that flat above the 1kHz, but the breakups are not that bad and it actually only goes +/-5dB. Upper end falls of like a rock at 8kHz. Than it lingers to about 16kHz, but at the level lower at least 20 dB. No nasty breakup modes, nice.
I am little worried about that weird dip at 700-800 Hz, even distortion rises at this point.
Now this is fresh driver out of the box, I will measure again after few weeks.
Otherwise it will be a great midrange, once paired with high quality tweeter. (I have something in mind, I have some linaeum tweeters left, they measure and sound beautifully.)

Thanks Paul.
Ed

[keantoken]

I've FINALLY got my OB to the point where it's functional. The top shelf hasn't been constructed yet.

I added 4 ohm series resistors, and this really improves the sound. Not only on the Betsy's, but on all the speakers I've tested it with. So maybe it's something with the amp? Anyways, a series resistor in my setup gives the highs less bite, and does a great help for the bass on my OB. Sounds more balanced now, and I can play it loudly without ear fatigue (I suspect the amp, it's only a cheapo Sony XPLOD thingy, but it's the best I have).

As you can see, my room doesn't quite compare to the gargantuan listening rooms everyone else seems to have. But it sounds good enough!!!

- keantoken

[kenpeter]

If thats BetsyK, Qts might be a little low for OB. Small series resistance could raise to taste.

[pjanda1]

Yup Ken, thats the BetsyK Keantoken is using. I suggested it because he is interested making boxes in the long term, while using OBs right now. I suggested that a series resistor should be get the BetsyK's effective Qts up to OB (Betsy) levels for the time being. I think 4 ohms might be a little high, but use whatever sounds best!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[keantoken]

Actually, I think both of you suggested I do that... I must be a slow learner.

I originally thought a series resistor would be an ultra-non-hifi solution, presumably because of all the folks talking about dampening and frequency response... I was surprised when Ken suggested such a thing, but I figured he had probably tried it himself without ill effects. Then I found the current drive thread and realized it may be interesting to try. All is not what it seems in this world, and the rest is history.

Even though the bass is stronger, there is a small peak around 50-60Hz just as predicted by the impedance plots. I wouldn't know just from listening, and I consider this drawback to be fairly benign compared to the alternative.

- keantoken