Line array for the betsy ?
 

I have an idea. How about 4-6 of the betsy drivers stacked vertically in a line array?

I had a pa column using 8" full ranges early in my audio life (kustom 300 with 6 x 8" speaker, some replaced with early 1990's rat shack full range with whizzers). It was fun and very loud.
Early 1970's Kustom Tuck & Roll Products

Then I came across this a couple of weeks ago. 4 x 8" but with a ribbon.
We've been wondering if is an ob or not (on the full range forum here). It uses the 8" hemptone fr8 drivers.
6moons audio reviews: J.A.F. Bombard
http://www.diyaudio.com/forums/full-...nsider-ob.html
http://i959.photobucket.com/albums/a...es/bombard.png

I was playing with a tang band w8-1808 and doing a bit on reading what a whizzer does for response and directivity. On an 8" coral, the whizzer added real high, but it also lowered (made flatter) the freq response from 1-5khz and improved dispersion from 2-4khz. I never knew whizzer design was such an art.
http://www.diyaudio.com/forums/full-...igibility.html

My 1808 really had only enough dispersion (highs) for 2 people sitting shoulder to shoulder at 12'.

So, by adding drivers and knowing how an 8" starts narrowing directivity past 2khz, I think you could easily add a bit of dynamics, keep the intelligibility, and gain higher volumes, all for not much cost. I don't think combing filtering would hurt 8" drivers.

Whatcha think ?

Norman

Norman,

I really want to try it. I know that comb filtering should be a problem, but I also swear I've seen anecdotes of it not being much of an issue. It could be that the narrow dispersion helps.

I just scanned that review. Notice the magnet, see any similarities? With the Q of a BetsyK and very little gain from that under-sized cabinet, I wonder if that speaker is an MTM with the bottom two run only as woofers. The other thing to note is that those drivers have a shorting ring, so they have much more treble from 1.5k or so on up to wherever they low pass them. That could well balance the effects of comb filtering.

I've wanted to try a line array, as I've had to tell so many folks that I didn't think it would work. Thats sad, as I could sell so many speakers in one shot! Last week my brother-in-law asked me about speakers for his classroom. I built some simple TL's for his living room, and he is very happy with them. He was thinking of something like that, but I don't think they have the dynamic capabilities and dispersion for a large music classroom.

Which brings us back to comb filtering. Those Kustom's aren't alone in appearing to ignore the conventional wisdom. I can think of all sorts of vintage speakers that should comb filtering problems but were well loved. Heck, I can think of some very expensive modern speakers that have two tweeters that look too far apart. If only I had a free weekend coming up!

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

anyone want to try ?
6 (220cm2 x 6) will have more area than a 15" (856cm2), woot.

Getting a cabinet built is probably an impossibility for me.

You may need an equalizer.

Norman

G'Day Diyer's

I've actually built something similar, although I can't claim full credit for the design, but more info on my build can be found here.

The best DIY speaker in the world? - DIY Audio & Electronics - StereoNET Australia

They are essentially an 'open backed box' and each driver is separarted by a shelf, to stop crosstalk and to provide bracing. I'm using a very cheap full range driver, found at my local Jaycar shop

8-inch Twincone 8 Ohm PA Speaker - Jaycar Electronics

They do need help from a tweeter, and I've tried several ribbons, planars, and domes sadly, from a cost point of view, they pair very well with my RAALS, which I already had, so the RAALS are going to stay. In the pics I'm using a HiVi RT2C-A Planar Isodynamic Tweeter, which sound good, but the RAALS simply shine, and sound OH! SO! natural and so much faster. And that's the problem, these things are very fast, in a different league of fast compared to power hungry modern 'Hifi' drivers, with heavy magnets and heavy cones. They also need help in the bottom octave, and I'm using a pair of Alphas in a 'H' frame for bass support, these will need updating though as they are just a tad too slow to keep up with my FR's and RAALS, but enjoyable for now. my hunt for a great well priced high sensitivity OB 15 incher continues.

I'm running these passive, and the crossover is very simple, LR2 on the tweet and Bass, and a inductor, so 1st order on the FR's just to tame the combined rising response, crossover ponts are 3k and 170hz, but you can vary these to suit your tastes, higher or lower, you have room to explore.

So how do they sound? Well I'll say this. I've never ever been as this excited about music and HiFi in my entire audio journey, some 20+years, these speakers simply tick so many boxes for what they do well, if I couldn't build another pair of speakers, or buy something better (N.B I'd have to spend plenty) i'd happily live with these for a long long time.

Doesn't seem to be an issue for several designs

Speaker Design Works

Schumakubin pictures by pete_schumacher - Photobucket

Prisstina pictures by pete_schumacher - Photobucket

Hmm.........

single .1uF on ribbon, 1 8" run wide open, a 1.8mH in series with 1 driver and 2 in series.

Not sure I'd call that a line array, but I've always wanted to play with a 6db (single cap) on a ribbon with a full range...........

Maybe assisted full range with supertweet and baffle step (or open baffle boost) ?

Neat.

Norman

Hi Norman, I should clarify. I'm using a second order on the RAAL, cut off is 3000hz. Second order on the Bass, cut off is 170hz, polarity reversed on the tweeter. I did try a second order on the full rangers, but they simply don't like caps in the signal path, it kills their sound, so just a small 0.44mh inductor filtering all 4 full range drivers, just to flatten out the combined rising response. To be honest I thought they would sound 'Honky as hell', but they simply don't, they certainly aren't a flat frequency response, but a 'Flat' FR to me sounds very dry and boring, lifeless in fact, so I've leant. Without really knowing it these speakers are approching the type of sound I've been listening for. I feel more connected to the music, within the music. There's just something that sounds right with these very light fast speaker drivers that when grouped together, reveal details and timbres and transients, that simply aren't there with other speakers I've built or heard before. Things like singers swallowing, chests filling with air, feet moving on the ground, or hands being rubbed on clothing, lips actually touching the mic, it's all there and more. I thought this level of detail would be tiresome and fatiging, but I I've done extensive 12 - 15 hour continuous listening and felt fresh and wanting more. All this from a very modest pre/power front end, and a cheap DVD player as a source, who knows what will come when I finally get myself a half decent DAC, let alone cables, and a proper amp? more work to do though speaker driver and cabinet treatments to do, and I may add another 15inch bass driver as well. All been well worthwhile thus far, certainly had it's ups and downs, and I've made it a point in this build to do it as a subjective project, resisting the urge to use a measuring mic and software my ears are to be my guide for this one. It takes allot longer, but t's been more enjoyable as well, and I'm learning more about myself as a music lover, and DIYer. It's certainly the last time I put cheap nasty speaker drivers in a box at the back of my parts cupboard that's for sure.:D

yea, this stuff is fun. Flat is boring, we like a bit of smile face if we use an equalizer. It's hard for me to find a driver that is not hot from the 1-4khz range.

Someone liked 8 x b200 in a flat array (those have a climbing response naturally).
post #589
http://www.diyaudio.com/forums/multi...allery-59.html

Visaton B200 in spruce baffle

here is a 5 page thread where the owner talks about the brutal .75ohm but excellent array.
http://www.audiocircle.com/index.php?topic=70643.0

my crest will do 2ohm, and at low levels it should be fine............

Norman

Definitely some irony pairing the RAALs w/ those Jaycars. ;)

I know, who's of thought:D Certainly felt quite odd putting them in the cabs. If budget is a real concern though the neo 3 offered the best alternative in sound. The only issue was it's a 4ohm and has much lower sensitivity, getting it to blend well with the FR proved too difficult in the end. I also think the Neo3's have gone up quite a bit in price since I bought mine.