Any threads on improving cheap speakers?

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Hi guys,

I grabbed a cheap and cheerful set of old sealed Sony 3 ways as a housewarming gift for a friend (along with an old marantz receiver they'll offer a huge improvement over the inbuilt tv sound) but after a brief listening session curiosity got the better of me so I opened them up for a closer inspection and well, they're poor to say the least.
Zero foam/fill, tiny magnets, minimal bracing, closed back midrange and tweeter cones etc etc The woofer appears to run fullrange and the other drivers simply have a cap on them.
I have a few ideas that I can implement with nothing other than some labour so I'd love to hear any suggestions for improving these?
I have an unlimited supply of the foam and am considering placing a lot of it behind the 10" woofer?
For additional bracing I have some broom handles that would fit the bill nicely?
Getting more complicated I have some small tang bands that fit into the midrange hole but that might open up a massive can of crossover woes?
What about making the enclosure aperiodic with a well stuffed hole?
 

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diyAudio Member
Joined 2007
Been there done that a lot
The foam helps as does a good bit of fibreglass stuffing
Some glue and corner blocking, bracing etc, slightly better caps on the tweeters but after that they will still be Cheap & Cheerful speakers, although there is nothing wrong with that.
Use them with a powered subwoofer so the small magneted 10: just does midbass and up works well, or even a passive .5 woofer with an inductor of suitably low DCR can work too
Foam is a very good start glued or stapled to the walls
 
Oooh, interesting ideas, thanks for the feedback mate. You have any pics or other inspiration? They are indeed cheap and cheerful, for $25 they're very good value, they make quite a reasonable sound compared to much more expensive smaller junk.

It's good to know about the foam, what's a suitable glue for that? I have PVA and I think some adhesive spray but I know some foams love to melt with the wrong adhesive (I'm looking at you polystyrene) Given I have heaps of it would you think putting an additional layer would offer much?

I really like the idea of a sub (I've mucked about with my own 12" semi sealed design and it works wonders) but I need to keep this simple, the floorstanders are already probably going to take up more real estate than my friends had anticipated.

Edit. I am trying to keep costs down and not buy anything I don't already have.
 
You shouldn't really get more than 1k, maybe 2kHz at the most from a 10" driver. There is probably a hole just above this region, and it probably has a peak in it from the woofer cone breakup.

I might fit the little 3" tang band I have in and see what happens? But for that to work well I'd need a pretty pricey inductor?

Edit and trying to bodge some chamfering (No routers here) to the chipboard enclosure to let the TB breath.
 
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I imagine woodglue would hold the foam nicely. Wonder if some 6x9 carspeakers could be turned passive. Must be someone willing to give you some for free. Ofcourse a shame to make a hole in speaker if it dont work out. I guess the tangbands should have same sensitivity at woofer, or there will be more work with xover. Maybe one can wind coils oneself? Cool project. I dont think you need to spend money on it. Just use scrap
 
I have spent hundreds of hours polishing tur...nips like these. Dope the cones, thinned pva will suffice, one coat maybe two at most. Brace the box, maybe add a choke to the mid, cheap film caps...don't sweat the small magnet it goes with a sealed box. I go a little ballistic on the woofer basket with epoxy putty and gutter repair tape since it is playing well up into the midrange but don't give away too much time on this sow's ear. Leave that to me.
 
Thanks for the excellent input guys. It seems I was on the right track but to get feedback/confirmation from experienced polishers is great.

So I think we're looking at stuffing with foam, cone doping (forgot about that one thank you phivates), upgrading the caps (local suggestions? would jaycar have these?) and bracing the cabs.

I might also replace the wiring as I have some higher gauge stuff around. Again as I have lots of this foam I might shape some around the front of the tweeter and midrange too, el cheapo diffraction be gone?

The tangband option I might leave but sticking an inductor on the woofer could be interesting.

I don't mind spending a little money on this, it's just good fun!
 
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Jaycar has plenty of appropriate caps. They have nothing too special but I wouldn't worry about that. What this project want is some consideration of its acoustic issues (the missing midrange), and a usable crossover. I wouldn't stress too much about the cable, provided it solders well enough.

It's too bad the Tangband needs too much work. Do you have anything that is already in a small enclosure that wants a woofer?

(PS, it's not that there is anything wrong with cone tweeters)
 
Cap values are 1 and 3.3 micro farad, 50v. Jaycar has some metal poly caps, not terribly expensive in the grand scheme of things but nearly the same price of the speaker to begin with :/

3.3uF 250V Metallised Polypropylene Crossover Capacitor | Jaycar Electronics

1uF 250V Metallised Polypropylene Crossover Capacitor | Jaycar Electronics

The tang band would need some work physically to get it to fit well on top of the chamfering, it's an 871 so I'd imagine pretty down on sensitivity versus that 10" paper woofer too? I'm becoming more inclined to stay with the little cones.

"Do you have anything that is already in a small enclosure that wants a woofer?" I have bits and bobs all over the place, what are you thinking?
 
What you have is two tweeters, so unless you swap in a true mid and crossover you'll have to live with the 10" mid-woofer. Like pro sound! Cheap and cheerful!!
I would look at broomstick bracing the woofer mounting holes to the back of the box, so that skimpy front baffle is relieved of the vibration somewhat. The upper two anyway.
 
What you have is two tweeters, so unless you swap in a true mid and crossover you'll have to live with the 10" mid-woofer. Like pro sound! Cheap and cheerful!!
I would look at broomstick bracing the woofer mounting holes to the back of the box, so that skimpy front baffle is relieved of the vibration somewhat. The upper two anyway.

I've got no real problem with that, I dabble with full range units so a 10" mid-woofer doesn't fill me with fear.

The sound is fine for $25, it's got some dynamics and bass, sounds best with simple things, I'd just like to eek a little more out of them :)

So the broom stick bracing, you mean 4 pieces to cover each screw hole? That's interesting.
 
For cheap, you can glue the 1" edge of a 1x2 (longest you can fit in the box) onto the side and back panels, vertically (the long way) just off center. The front to back braces near the woofer are a good idea. Any film cap (even mylar) will be better than electrolytics.

Lining or stuffing the box will help a lot, but keep it from touching the woofer or blocking the basket cutouts.

These boxes may be quite sensitive, see if you can find the specs. Rather than putting in a "midrange" it would be easier to just add a fullrange to the box and cross it in at 500Hz or so.
 
Thanks Ron, I need to do a bit more research on the cheap caps as I'm not too familiar with whats good or bad

The fullrange idea is what I had in mind. I have my concerns about the added cost/complexity there but I haven't discounted it yet.

Would the addition of foam compensate for the volume lost to the vertical reinforcement with the 1x2?
 
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