• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Apparently, I suck at math + need advice

Give us time :D

If he wants to go that route; there's lots of Advents here I can hook him up with and BauHausler (Advent E-waves) and I were talking about his new DQ-10 Ewave project in Wiggy's very own house Saturday.

But right now I think a new tweeter would be a good start...
 
Andyman said:
Give us time :D

If he wants to go that route; there's lots of Advents here I can hook him up with and BauHausler (Advent E-waves) and I were talking about his new DQ-10 Ewave project in Wiggy's very own house Saturday.

But right now I think a new tweeter would be a good start...
Click to expand...

Thanks, buddy. Here's some photos. Sorry for the delay, just got back from the dojo. I hurt.

The tweeter in question:


100_3077 by Wigwam Jones, on Flickr


100_3078 by Wigwam Jones, on Flickr

This is the woofer:


100_3082 by Wigwam Jones, on Flickr

This is one of the caps (I think):


100_3081 by Wigwam Jones, on Flickr

I think it says: 4UF 25V N.P.

Then there is this thing. A resister? Can't tell, and I'm afraid the colors are not really very helpful to me. I hope my photo is displaying them in their true form:


100_3084 by Wigwam Jones, on Flickr


100_3085 by Wigwam Jones, on Flickr

So is this the entire 'crossover' network? Just a cap and a resister? Should there be some coils or something down inside the speaker guts? I haven't pulled out the fiberglas yet, but I can.

Thanks!
 
Looks like white, red, gold, silver. That'd calculate out to 9.2 Ohms +/-10%

Really hard to tell that first color but I don't see any silver listed for a primary number so it must be white.
 
Gray-red-gold, maybe? That would be 8.2 ohms. That's a pretty standard value.

Looks like a cap in series with a resistor, then to the tweeter.

With that, you can substitute another tweeter, pretty much without having to worry about the crossover "freaking out" or anything. You may wind up needing to change the value of the cap and/or the resistor to "maximize" the use of the new tweeter, but it'll definitely be OK just to try another one...

Wiggy, can you take a picture of the resistor, with a piece of white paper in-frame somewhere, so we can compare (and also, to "trick" the camera white balance into shading the gray part properly, if it is gray) that to the first band of the resistor?

Regards,
Gordon.
 
GordonW said:
Gray-red-gold, maybe? That would be 8.2 ohms. That's a pretty standard value.

Looks like a cap in series with a resistor, then to the tweeter.

With that, you can substitute another tweeter, pretty much without having to worry about the crossover "freaking out" or anything. You may wind up needing to change the value of the cap and/or the resistor to "maximize" the use of the new tweeter, but it'll definitely be OK just to try another one...

Wiggy, can you take a picture of the resistor, with a piece of white paper in-frame somewhere, so we can compare (and also, to "trick" the camera white balance into shading the gray part properly, if it is gray) that to the first band of the resistor?

Regards,
Gordon.
Click to expand...

Here's the photos you asked for:


100_3086 by Wigwam Jones, on Flickr


100_3087 by Wigwam Jones, on Flickr

Mrs. Wiggy looked at it and said grey-red-gold-silver reading left to right. Does that sound right?
 
OK, if I read that right the 4uf cap is crossing you at 5000 hz, which is high and good as you can use a lot of tweeters. The concern with tweeters is that they can go low enough to mesh well with the woofers, but 5000 Hz is pretty high so you can use almost anything.

And it looks like the resistor is toning the output down, which is also good as that indicates that lower output tweeters may work well too and not need to be reined in. It's easy to turn them down; but you really can't turn them up.

Are you still at the Tech Center? If so, swing by here on your way home some day and I can probably hook you up with a couple of the EPI tweeters and maybe a few fresher caps to play with. The only issue I see is that the magnets may be bigger than the hole in your cab, so some fudging may be needed, like screwing it onto a cover plate to seal the hole so you can test it out before you carve up the cab.

Let me know...
 
Andyman said:
OK, if I read that right the 4uf cap is crossing you at 5000 hz, which is high and good as you can use a lot of tweeters. The concern with tweeters is that they can go low enough to mesh well with the woofers, but 5000 Hz is pretty high so you can use almost anything.
Click to expand...

Wait a sec... you gotta consider that resistor in series, as PART of the "load" that the crossover cap will see, when considering the effective crossover point!

Adding them, that's about 16 ohms (8.2 for the resistor, 8 plus or minus a bit for the tweeter in series). That would make the crossover more like 2500 Hz.

That's OK for the CTS cone tweeter in question... and would also be fine for something like the Dayton Classsic DC28F soft dome (they're OK down to 2KHz). It would also be just fine for the EPI dome (if you used the EPI or Dayton tweeter without the resistor, just use an 8uf cap instead of a 4uf)...

Regards,
Gordon.
 
Thanks Gordon!!
I'm pretty green at some of this stuff, but I knew there were some real pros that would chime in before we got too wacky. I'm pretty sure we have some 8s here we can clip in.
 
GordonW said:
Wait a sec... you gotta consider that resistor in series, as PART of the "load" that the crossover cap will see, when considering the effective crossover point!

Adding them, that's about 16 ohms (8.2 for the resistor, 8 plus or minus a bit for the tweeter in series). That would make the crossover more like 2500 Hz.

That's OK for the CTS cone tweeter in question... and would also be fine for something like the Dayton Classsic DC28F soft dome (they're OK down to 2KHz). It would also be just fine for the EPI dome (if you used the EPI or Dayton tweeter without the resistor, just use an 8uf cap instead of a 4uf)...

Regards,
Gordon.
Click to expand...

Totally blew my brain away! Can you simplify that a bit for a dunderhead? I sincerely appreciate it!
 
GordonW said:
+1 on that. That's about the estimate I'd make too.

Replacement tweeter? The Dayton Classic DC28F from Parts Express. No question. It should work with simple (i.e, just a cap) crossovers OK. Might need some resistor for an L-pad, but I doubt even that. For less than $20 each, they're pretty darn good!

EDIT: The EPI/Genesis type inverted-dome that Andy suggested should also work well. They'll definitely play well down to below 2000 Hz. The factory 10uf cap is about 1800 Hz, IIRC...

Regards,
Gordon.
Click to expand...

even better, the shielded version right now is under $10!

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=275-075
 
Wigwam Jones said:
Totally blew my brain away! Can you simplify that a bit for a dunderhead? I sincerely appreciate it!
Click to expand...

When Gordon starts with the tech talk, just smile, nod, and take notes.

Basically, lose the resistor and put in an 8 uf capacitor, if you are going to use Andy's EPI tweeter, or the Dayton from Parts Express.

Me? I'd just use the EPI, but I've used the Dayton, it's very nice, and on sale for less than half price.
 
luvvinvinyl said:
Basically, lose the resistor and put in an 8 uf capacitor, if you are going to use Andy's EPI tweeter, or the Dayton from Parts Express.
Click to expand...

Just to be clear - you mean if I go with the EPI, change the cap to an 8uf and leave the resister out of the circuit. If I go with the previously-mentioned 1/2 price Dayton, keep the 4uf cap (a new one, of course) and a new resister as well. Or did I screw that up? :scratch2:
 
I have 8s and EPIs; why don't you borrow them and see how it goes before you committ.
The price is right...:yes:
 
EPI tweeters are hard to beat. I had a pair of the xp55b, maybe still do in the pile. This may be a way to put them to use or make them useable to someone else. Let us know how you like the upgrades and if it's worth it.
 
You must log in or register to reply here.
Back
Top Bottom