Kustom KGA10 and the wild things I want to do

[dovedescending]

Greetings and such.

In these troubling economic times, I don't have much cash to throw around. So the only amplifier I have right now is a Kustom KGA10, 10 watts of mildly crummy sound through a mildy crummy 6-inch speaker in a mildly crummy 10-inch cube. Fortunately(?) I have this insatiable desire to pull things apart and modify them.  :trouble So here's my idea.

I pulled the back off for fun, and it looks like everything but the speaker would come out easily. I plan to make a small amp head that I can carry in a backpack.

The amp puts out at 4 ohms, and I presume wouldn't much care for dealing with 8 ohms. I want to wire four 4-ohm speakers together like so: two each in a series pair, then wire each pair (treating each pair as a single 8-ohm speaker) in parallel, which if I'm right should result in an overall resistance of 4 ohms, meaning my amp won't freak. I would put these speakers into a small cabinet (to be created from some sort of scrap something).

I am hoping that using for speakers might result in somewhat better tone quality from the amp, even if it is a cheapo.

Now here's what might be the crazy part.  :loco In order to facilitate portability, and in cheapness, I was thinking of using 4 3-way car speakers, something in the 5x7 oval crowd, or 6.5 inch rounds. I know that car speakers are not optimized for guitar use, but they are lightweight, decently cheap, and can generally be found responsive to the 45-20,000 hz range, or at least as low as 60 hz. My understanding is that the low E on a guitar is 83 hz or so, so hopefully this range would be just right.

Thoughts, concerns, and snide remarks are appreciated...

[J M Fahey]

Not sneering at all.
A 5x7 or 6" round is basically the same you already have, not much to gain, *but* an old 6x9" , the real old , not 3 way , rubber/foam edge but the cheaper single cone, paper edge type is something to consider.
$ of them in a cabinet will push some air.
Of course the only price worth paying is 0.00 $, just reclaiming them from car junkyards.
If you will pay $20 to $30 for the lot, buy an 8" Mod instead, that's a real guitar speaker.
The idea of a micro head is cool.

[dovedescending]

here's a questions concerning the cabinet... for both car speakers and the jensens (because i would have two at least), what sort of spacing would you recommend between them?

[Brymus]

Space them like they are guitar spkrs.
Like in a 4 x 12 cab.
Leave the back open and experiment with open/closed back.
JM said it !!! ,use spkrs that DONT!!!  have the rubber/foam suspension on them.
And remember 1 high efficiant guitar spkr (like a Jensen MOD) will be louder and have better sound than 4 of any less efficiant type spkrs.

[dovedescending]

Well, now, I'm all curious. What's wrong with rubber suspensions?

Thanks for all the help. This website rules.

[J M Fahey]

There's nothing wrong with rubber or foam suspensions by themselves, quite on the contrary, but they usually indicate an "audio speaker", which to get more bass in a small enclosure uses very long , inefficient voice coils usually 2 and even 3 times *longer* than the magnetic plate, which means only 1/2 or 1/3  of them "works" and the rest is loss, they use thick , heavy wire (no attack, no treble), thick cardboard cone, heavy epoxy adhesive, etc.
You can't open and measure them at the shop, but you can easily see the foam border. The designers are not crazy, today it's very easy to get cheap high powered amplifiers and they willingly sacrifice efficiency for "quality".  And if they lose mids and highs, they add specialized units. Fine, but not for guitar. In a car, it's easy to have 30 to 500W amplifiers.
Try to move those speakers with a Ruby !!!!
Very old (60's and early 70's) car speakers or somewhat more modern very cheap ones or TV speakers were driven by 2 to 5 watt amps, so they *needed* more efficiency, excellent high mids (where our ears are most sensitive) and sacrificed bass. ¿Do I hear somebody screaming  "guitar speaker"?

[dovedescending]

 

My goodness. I have opened a can of worms i never knew existed. I think Jensens sound like the way to go. Thank you guys so much.

Out of curiosity, in the spirit of keeping this project as cheap as possible, what should I use to build the cabinet? I was thinking of buying some crappy shelf or something from the thrift store to use as scrap.

[J M Fahey]

Hi Dove.
It depends on your tooling.
Maybe the cheapest way will be going to your local Home Depot equivalent and have them cut some MDF or chipboard to size.
A few minutes with nails, glue and hammer will reward you with a nice cabinet.
You'll still need a jigsaw for the holes.

[dovedescending]

I have a variety of things I'm doing to my guitar as well... can anybody direct me to a similar forum of DIY'ers for guitars?

[awdman]

What do you want to do with your guitar, we might be able to help.

[dovedescending]

I have an Agile guitar, an Epi-like Asian double-cut Les Paul copy that plays like butter, but sounds at best okay. At some point the rhythm pickup quit on me, so I ripped it out, along with the three way switch and one each volume and tone, and rewired for one pickup, one volume, and one tone. Now I have three unsightly holes plus a pickup cavity to either cover up or use productively. (As an aside, has anyone ever seen a Les Paul that has had one pickup removed, and the cavity covered tastefully? I'm in the market for aesthetic ideas.)

Here's what I'd like to see happen to this guitar. I'll start by replacing the pickup with something higher output and 4-conductor, so that I can use one of the holes for a coil-tap switch. I'd like to use the other hole for a VariTone-like control. I'm a little fuzzy as to how to go about wiring a VariTone, because my understanding was that capacitors bleed treble frequencies, but the Gibson BluesHawk seems to have settings that bleed off mids and such. So I'm not sure what values of capacitor I should use to achieve different "EQ" type effects.

I want to use the final hole for a Black Ice passive overdrive capacitor from Stew-Mac. I found one video on YouTube  http://www.youtube.com/watch?v=awCcC6U-5K4 and it seems like even though it's designed to be used with a pot, it wouldn't do much unless it was all the way on. So I'd just use a switch. Or I may throw it onto the VariTone with all the other capacitors. I haven't decided.

The goal is to have a simple one-pickup setup that still takes advantage of as many possibilities as are available.

[J M Fahey]

Hi Dove.
Don't waste time with the black cube, or if you want to experiment, just use two regukar diodes back to back.
Read:
http://www.thegearpage.net/board/showthread.php?t=95792