TM Bookshelf Advice

[cckidd2]

Alright, I've decide to just make my own small bookshelf speakers. I have the Dayton DA135 as my woofers and the Dayton ND20 as my tweeters. I bought the Dayton 4.5Khz x-over. I was going to add a zobel network to improve it though. I will make my own crossover when I get more experienced as I'm only 13. My box design is Height - 10.5" Width - 7.25" Depth- 9.5" and a 2" x 6" Port. Any advice about the box size and zobel with be greatly aprreciated.

[arlis_1957@yahoo.com]

go for it and see if you like. i dont think that the 135 will go very low or handle much power.

[cckidd2]

Alright thanks. I will post pictures when I'm done. I will probably start on friday. On the zobel I was going to have a 15uF capacitor and a 8 ohm resitor.

[Mayhem13]

Box volume and tuning is just right at 55hz......nice job. As to the Zobel, sorry i can't be of more help. Z doesn't swing too much but hey. Please don't forget the Lpad to match the tweeter to the midwoofer...more critical than the Zobel in your case.

[cckidd2]

Thanks How would I calculate the right components and their values for the LPad?

[patrickm]

I thought someone did a design using the ND20FA and the DA135 a while back. Turns out Shawn_A did it, but the image of the crossover isn't available. a few folks said they built it and liked it, so if you're not ready to try your own crossover design yet (and no worries, that's a big step for lots of people here), but want something better than a stock XO, you might want to PM shawn and see if he still has the crossover writeup. It probably wouldn't cost much more, and possibly less than the stock XO's. just use electrolytic caps if cost is an issue. hope that helps.

http://techtalk.parts-express.com/sh...t=nd20fa+da135

http://techtalk.parts-express.com/sh...t=nd20fa+da135

here's an L-pad calculator online -- it doesn't really account for any effects on the slope of the response though
http://www.diyaudioandvideo.com/Calculator/LPad/

[cckidd2]

Also, what mods do you guys reccomend to a dayton xover with those drivers?

[tom_s]

Also, what mods do you guys reccomend to a dayton xover with those drivers?

The best advice I could give would be to return them. There have been quite a few people here that have used those drivers and it sounds like Shawn designed one using both! It would be MILES ahead of the stock xover. Have you seen Paul Carmody's (aka. Undefinition) writeups on the subject? It's a plain English FAQ that spells things out. Great for the first-timer...even the 3rd timers!

http://sites.google.com/site/undefinition/diy-mfaq

[tom_s]

As a follow up- have a look at the measured response of the DA135-




That peak at 9KHz is going to sound pretty nasty with the stock crossover. You need some steep slopes or other means of attack to knock that thing down-especially if you're trying to push that driver out to 4.5K!

[cckidd2]

I only bought them because I'm not to good with designing crossovers. That's why since this is my first project I just bought the premade ones. Im just gonna build this one and see how it sounds. Later when i learn some crossover skills i will take out the premades and enter my custom ones. Do you know a good simple schematic for those two drivers? and thanks for the reply

[patrickm]

I'd agree with tom - the breakup would be audible, and not in a positive way. you could probably get it down with one (specifically chosen) extra capacitor in parallel with the inductor on the woofer, but the better idea is probably to send back the pre-made x-overs and build Shawn's instead, presuming he still has a schematic and parts list.

[cckidd2]

Thanks patrickm, I will look for the schematic. Could you give me a link for pics of the build please?

[daveh]

Thanks patrickm, I will look for the schematic. Could you give me a link for pics of the build please?

I'm not sure if this was ShawnA's schematic or not. Just ran across it on my hard drive.

Hope that helps.

DaveH

[cckidd2]

Thanks all you for the advice. Thanks DaveH for the schematic. I will use the premade dayton crossovers then later on I will make that crossover from the schematic DaveH posted.

[JimHRB]

Thanks How would I calculate the right components and their values for the LPad?

There are a number of calculators online. One is www.diyaudioandvideo.com. You could also just buy an adjustable one and tweak the tweeter volume by ear.

[the kid]

IMO - the best simple result you can get is sending a pm or email to shawn_a.

I see in an "OLD" post that he has a project just like yours. But the page is not found from the link. This way, you have a nice design using your parts that you don't need to keep guessing at how to improve.

Should not cost much.

Sorry for not answering your xo questions as I do not design these either.