Newbie DIY bookshelf suggestions wanted (1 Viewer)

[Chad Sunderland]

Hi, I just got a set of KLH bookshelf speakers on sale at BestBuy for $20! I know KLH isn't a good brand, and I didn't really NEED these speakers, but for $20...it was just too good, not to buy them. In the store...I didn't think they sounded too bad...then again I didn't put them against any other speakers there, I wasn't even shopping for speakers! Well, when I brought them home and put them up against my Axiom M22's, they got TOTALLY out done, I did expect that though, and would have probably been more upset if they wouldn't have!
So anyway, I hooked these KLH's up to my Sony shelf system in my bedroom, they do sound better than the factory Sony speakers, but I'm hoping to make them a little better.
Since I have the cabinets, I'd like to just replace the drivers, and would like some opinions. I've never tried anything like this before. The drivers are 1 8" woofer, a 5 1/4" mid, and a 5/8 tweeter, but the plastic surround on the tweeter measures 3" across, so I can go bigger there. Also, the cabinet is sealed.
I don't have a set budget to stay under here, but I'd like to keep it as cheap as possible. I'm just looking for a moderate improvement, so I don't need $100+ drivers in it. In my bedroom I normally listen to louder rock music, so for these speakers I'd like a more "in your face" sound, and a pretty good kick from the woofer...as opposed to the Axioms which have a bit more laid back, but very detailed sound.
First off...what type of crossover do I need? Anyone have any idea what type of crossover is already in the KLH's and if it would be worth using?
Secondly, I desperately need suggestions on drivers, I've been checking them out on Parts Express...but I have no experience with any of them. Also...would I benefit from porting the cabinet? If so...what size port would you suggest. I know the port depends on the speaker, and the size of the box, but is there a certain size that works moderately well with most speakers? I have no clue how to find out "exactly" what port would be best. +
Thank you so much for any suggestions!
Chad

 

[EmetW]

Ah, man, I want some $20 "bookshelf enclosures" That's a good place to start with-what do the crossovers look like that are in there already? Was the 5 1/4" in a separate chamber or was it a sealed back basket or neither? If neither or sealed back, whatever 5 1/4" you end up getting will require you install a dividing board to separate the airspace betwee the 8" and the 5 1/4". I'm learning right now with my home towers that going with a three way is a pain to do but the crossovers in the speakers now may be enough to get by. For drivers, get on MCM electronics' mailing list (www.mcmelectronics.com). They have some good but extremely inexpensive drivers, and check ebay as well-in fact there are a pair of Vifa 8" woofers for $25, 5" mids for $20, and D25AG 1" tweeters for $25. That makes for one heck of a speaker for less than $120 total!!! Good luck!

 

[Chad Sunderland]

Thanks for the input. I haven't pulled the speakers out of the enclosure yet, I'll do that tomorrow and let you know what I find out. Also...those speakers are still on sale! The BestBuy employee told me it was on clearance, they are normally $70 a pair.

 

[Dave Poehlman]

Anyone have any idea what type of crossover is already in the KLH's and if it would be worth using?

I wouldn't expect to see much in there other than perhaps a capacitor on the tweeter.. and maybe the midrange.
As far as replacement drivers go, check the sale pages at www.madisound.com & www.partsexpress.com (as well as the aforementioned MCM) I've always been partial to ferro-fluid domed tweeters. They just seem to have a smoother sound to me... and polypropylene cones on the mids and woofers.
You might even be impressed by keeping the existing drivers and adding a simple crossover. You'll probably see an improvement in clarity.
I always enjoy the more frugal projects. I'm not into DIY for audio purity.. just to see how much I can get out of how little... if I can get some audio purity out of it as well, all the better.
Let's start by looking at that enclosure. What size is it? What's it made of?

 

[Chad Sunderland]

Ok guys, I just pulled the drivers out to take a look at what is in there.
There is a simple crossover just hotglued to the back of the cabinet, 2 capacitors and 1 resistor (I think...not very knowledgeable about crossovers). The cabinet itself appears to be made out of the same stuff the cheap desks and entertainment centers you get at Wal-Mart are made out of. I'm not sure what it's called, but it looks like very tightly pressed wood pulp. It does seem pretty sturdy, and doesn't seem like it would give off any unwanted resonance. The size is 16.5"H x 11"W x 10"D. You can see them here:
http://www.bestbuy.com/Detail.asp?m=...at=&e=11166707
And...they are still $20, with free shipping! In fact I just ordered another pair, not sure where they will go...but I just can't pass up a deal like that.
As far as the drivers, there was no type of divider behind the 5". It is not a sealed design either, just a standard open basket speaker. There are no dividers anywhere in the cabinet. What do I need to do here? I'm not sure what is meant by "divider plate" as EmetW suggested.
So...do you guys think I should try out the crossover in the enclosure, or should I try something like on of these from PartsExpress:
http://www.partsexpress.com/webpage....ctGroup_ID=194
Also, as far as drivers, I've heard good things about those Vifa drivers, and they do have great prices too! I'd really appreciate opinions on what particulare drivers to use from someone who has more experience. Also, if you think I can get a better bang for the buck from a brand other than Vifa, please let me know!
One problem I am seeing when looking at the Vifa woofers on PartsExpress is that it says to use them in a vented enclosure. Will they work well in sealed, or should I go with a port? If so, what size and placement should I use?
I'd love to hear suggestion on particular drivers to go with, there are quite a few to choose from, and I don't know what will work best for me. If the cheapest Vifa drivers are decent, I think I would like to go with those, I don't mind spending a little more on the tweeter though, I like a lot of fine detail in my music.
Thanks so much for all your help!
Chad

 

[Chad Sunderland]

bump

 

[Dave Poehlman]

The cabinet itself appears to be made out of the same stuff the cheap desks and entertainment centers you get at Wal-Mart are made out of. I'm not sure what it's called, but it looks like very tightly pressed wood pulp. It does seem pretty sturdy, and doesn't seem like it would give off any unwanted resonance. The size is 16.5"H x 11"W x 10"D.

It's particle board. Not as dead as MDF, but what do you want for $20. I'm guessing it's only 1/2" thick. Which gives you around a .8 cubic ft box. Now it's just a matter of finding drivers that'll fit well in that size enclosure.