Krazy experiment: SDA + Ribbons hybrid.

Ricardo

Scenario: I was bored; kids and wife were out and I was moving the 3.1TL's to replace the AL-III's; I do this swap once in a while, since I enjoy both speakers; each has its own strenghts.

While I was at it, a crazy idea crossed my mind; I have two outputs on my pre, and an Adcom 535 used for the backyard speakers...hmmmm.....what would happen if I used one amp for the ribbons, and one amp for the SDA's????

I connected the Belles to the ribbons, without the woofer, and the Adcom to the SDA's, without the tweeter.

WOW!!!! what a way to fill the room with ribbon's highs/mids, SDA punch and soundstage. The 535 does a great job driving the bottom end of the 3.1 TL's...did not expect that.

There is some weird blending problem that makes some frequencies "not enjoyable" ....but with some crossover tweaking, and using a bigger amp for the SDA's, I think that great sound could be achieved.

Not that I actually want to do this....but any thoughts out there from speaker experts? Is there a reason why this would definitely be a bad Idea???

amulford

No. The SDA driver is basically a mid-range inverted signal/ The only thing I see is, with the ribbon you're using being full range, you maybe get some over lapping cancellation.

F1nut

Hence, the weird blending problem.

beardog03

amulford wrote:

No. The SDA driver is basically a mid-range inverted signal/ The only thing I see is, with the ribbon you're using being full range, you maybe get some over lapping cancellation.

Ant,Dude...!
You continue to amaze me...:cool:

Rock on brotha


Hence Jesse`s right...!!!!!



again

Ricardo

Yes; I guess that in the range around 200-2000Hz (just guessing here) there's the problem. tweaking the crossovers to cancel the signal above 200Hz into the SDA would probably fix that, but then you wouldn't get any benefit that you couldn't get by adding a sub with the AL's. As said, crazy experiment; just having some fun.

ben62670

be careful most ribbons can't go below 4000, and if not crossed over properly they will blow. You may be experiencing not cancellation but a wide range of frequencies that are missing between 2000 and say 4000 to 6000. I have some emit k's which i would love to use, but you would need either 3ways, or a mid bass that is capable of going to 4k.

Merry Christmas, Ben

Normanality

The AL III's are actually crossed over around 250Hz. Some guys at the Carver forums have found that by replacing the woofer (like yours) and using an external crossover around 400 Hz makes a huge difference! I believe they used a Behringer active crossover that can be set up with the proper notch filter for the ribbons. The woofer in your AL III's are actually Infinity Reference that are rated 25 - 450Hz.

ben62670

Hi Norman I'm just double checking. I see you stated 250HZ, 400hz, and 450hz. Did you mean 2500, 4000, and 4500?

Merry Christmas, Ben

Normanality

ben62670 wrote:

Hi Norman I'm just double checking. I see you stated 250HZ, 400hz, and 450hz. Did you mean 2500, 4000, and 4500?

Merry Christmas, Ben

Hi Ben,

No, the Carver ribbons were actually designed to go down to 250 Hz. Thats asking a lot from a ribbon. The thinking behind raising the crossover to 400Hz was to take some of the load off of the ribbon. There's no midrange driver in the design to take up the load between the subwoofer and the ribbon.

Normanality

Just perusing some of the old threads at Carver and I was wrong!

The crossover on the AL III is 150Hz not 250Hz :eek:

ben62670

Wow, where can I find some specs on the carver ribbons. I love my emits, but they require way to high of a crossover point for me to use them in anything practical but a three way.

Thanks Ben

unc2701

Whoa- I've just been doing a similar experiment... Using the subs on the Gallo's I picked up from Russman combined w/ the LSi 25's w/o their subs. Been trying to pin down what I like about each.

Anyhow, you could throw some high-pass Fmods on the ribbons & bring their crossover up a bit. You'll probably still have a blending problem (phase & slope won't have been engineered to work together), but it'll sound a little better. I'd keep the midrange on the SDA's since, well, you don't want to lose the SDA effect.

Ricardo

Guys, I have no intention of modifying a perfect pair of SDA's; I like them as they are; I was just experimenting for fun.
My plans are actually rebuild the crossovers of the SDA's to make them better.

Fot the AL-III's I like the idea of using active crossovers to play around with the settings for the ribbons/woofer. This is something I might do....Don't get me wrong...I love how they sound, but the idea of making them even better sounds good...

Thanks for all the input.

dorokusai

Bang your head against the wall and hook one pair of speakers up again.

Ricardo

I have only the SDA's playing; the test was a 30 minutes...test.

dorokusai

Lesson learned.

amulford

ben62670 wrote:

Wow, where can I find some specs on the carver ribbons. I love my emits, but they require way to high of a crossover point for me to use them in anything practical but a three way.

Thanks Ben

It depends on the ribbon. There are three incarnations. A 30 inch, a 48 inch and a 60 inch. You can still get them, but they aren't cheap...