Mdifying cheap speakers for better tone and more power

[oxydon]

This is a very challenging topic that gives no results in google at all, virgin lands? anyway, i will post the trivial question here and then discuss the answers one by one so that we can find more tricks and infos ...etc.
So, given that we all have access to real cheap speakers in the market, that these speakers have the same types of magnets than the high-end stuff, and that all of them have strong iron structures, and that most of them have quite good quality cones, ...etc : What are in your oppinion the possible modifications that one can make to these 15$ speakers to improve their tone (played as is, most of them will sound really DEAD), to improve the SPL (most of them have very low SPLs), and to improve the max RMS power rating ?
think about all options, including but not limited to: fitting a custom made voice coil, putting a higher quality cone, strenghening/loosening the existing cone, "aging" the speaker with an alternate source, ... think free, and open, the sky is the limit.
i can't wait to reaad your answers and ideas, post anything that springs to you mind, this is a high value project!
More later.

[TweeDLX]

If I was going to spend money on "fixing up" a cheap speaker, why not spend it on a "good" speaker...? :jo
I suppose if I was handy with speaker repair (which I'm not) it might be fun to improve a nothing speaker into a something.

Mike

[rockon1]

I dont know about fixing cheap speakers but Ive modified decent speakers to sound better for my purposes. Bob

[SatelliteAmps]

I think part of the issue is that the cheap speakers don't actually have the same parts and materials as the expensive speakers. There isn't a whole lot to do about that to make them sound better.

[Rosewood]

Wall art? But seriously about all you can do is waste money and time and end up with a less than decent speaker. If the frame and magnet are good enough then you can try a recone kit for something like a celestion but that's like throwing darts, you don't know what you'll get.

[oxydon]

TweeDLX: it seems to be actually very fun to do this stuff and experiment with it, and the repairs are really cheap if you are quite tricky with it, but our first goal is to build up some knowledge about this stuff and also to Do It Yourself.

Rockon1: tell us about your mods anyway, there might be some good ideas!

SatelliteAmps: what materials do you think are different? except the cone i think the other pieces are made of quite the same things (maybe different specifications ..).

Anyway, these are some of the differences i could notice in guitar speakers Vs Hifi bass drivers:
- The cone are almost always in a waved shape, this allows it to break-off (bend) under high pressures.
- The voice coil is designed to partially leave the magnetic field in the high peaks, this is believed to creat a sweet natural distortion.
- The joint between the cone and the iron structure is stiffer, so that it doesn't bend easily, again it has to do with compression and distortion.
- The speaker must behave correctly in the midrange, especially the low-mids, the higher cuttof frequency should be somewhere from 4 Khz to 6Khz (roughly).
- ... Any other suggestions or howto's?

[VacuumVoodoo]

For starters:

Cone shape - can be straight,, hyperbolic or exponential cross section.
Guitar speakers use straight cone, sometimes ribbed, straight is cheapest to manufacture
Material - paper, recycled or non recycled raw material, short fibre or long fibre, textile fibre etc. fibre binding material affects cone stiffness more than you'd think.
Thickness gradient across cross section. Want cone cry? It's in the gradient.

You can begin by learning to cook your own paper mush and make some cones.

It's fun, really. No, I'm not joking or sarcastic. Been there, done that, it is fun.

[doc]

Probably the most productive approach is to focus on the cab you'll be putting it in - if you optimize the cab to make the best of the speaker's strengths you'll have the best result. I'll echo the thoughts of others, however, and say I'd suggest picking the best speaker for the job FIRST and not try to make a silk purse from a sow's ear.

[donnyjaguar]

Years ago when I worked as a tech it was slow one year so I modified some el-cheapo speakers from stock into a pair of two-way bookshelfs. The drivers were full-range style that you'd find in consumer grade televisions etc. The "woofer" was a 6-1/2" model with whizzer cone that I stuck lots of felt to the back of the cone to improve mass and damping. I carefully removed the whizzer with a razor knife. It worked. The "tweeter" was a 2" speaker which I completely sealed the back of the basket with tape then doped with epoxy. I also put more rubber cement around the edge of the suspension to stiffen it a little more. This also worked. The cabinets were made from birch plywood shipping cartons and damped with a little styrofoam - not much. There was no port. For the crossovers I used regular electrolytics with the negative terminals tied together to create non-polarized ones. For the inductor I used the secondary winding of small power transformers from the parts bin. They weren't very efficient but certainly had a nice full-range tone to them and worked fine in the workshop. Nearly forgot to mention, the amplifier was made with a pair of audio power amplifier ICs (also from stock). These rated at 8Watts each, although I ran them at about 18V to bump this up some more. Gain control was also a stock dual-gang unit of 250kΩ pillaged from stock.

[OlAndrew]

I've gotten some good results (and some not so good) spraying Krylon clear on the cones and surrounds of old beat-up speakers. Never tried it on a new ElCheapo.

[rockon1]

I bought some Relic 30 Celestions that were being liquidated at 29$ a piece. They were part of a one off batch or test run. Rated at 60 watts,large 50 oz magnet -similar to a v30. However they were darker and had less break up. The one noticable difference between the two was the small ,thick paper dust cap on the Relic 30's. I removed the large screen dust caps from "donor " speakers and glued them to the Relic 30's after carefully removing their paper caps with a razor blade. Night and day difference. The Relic 30's ended up saounding more like a CL80-more open,even and much more high end than they origianally hasd. Heres some pictures


Donor left, Relic unmodded righthttp://i37.tinypic.com/rjpl6q.jpg
Removed cap from blown donor

http://i38.tinypic.com/ftzjeq.jpg

Donor dust cap trimmed and Relic 30 cap removed

http://i38.tinypic.com/2rq29z7.jpg


Donor cap in place on Relic 30.

http://i33.tinypic.com/aaxgl0.jpg

Finished Relic with donor large screen cap. Note: Glue is slightly wet still-it drys clear. Bought the glue from Parts express. Bob

http://i33.tinypic.com/35d1b9v.jpg

[VacuumVoodoo]

Nice job. Dust cap is a misleading name, it is in fact the HF dome, diameter, shape i.e. profile and material is what basically determines treble response. If you really wish to extend treble response make one of thin light metal or coat a paper one with hard acrylic.

[rockon1]

Nice job. Dust cap is a misleading name, it is in fact the HF dome, diameter, shape i.e. profile and material is what basically determines treble response. If you really wish to extend treble response make one of thin light metal or coat a paper one with hard acrylic.

Indeed misleading. It even affects the cones stiffness and can change the amount of cone break up and the way it reacts to distorted tones. Since the above pictured speaker went from a stiff paper cap to a large screen the change was dramatic to say the least. Bob

[jh45gun]

Why Bother I can buy good used high end Guitar and PA speakers at the local music store for 20 to 40 bucks. In the past I have bought 12 inch Eminence's Celestion's and Some really heavy CTS tens. Also offerend were brand name Crate or Carvin or Fender which could have been made by also Eminence or Celestion. I know Eminence made speakers for Fender Crate and Carvin. That is just what I bought in the past year or so I would suspect they may get JBLs and other premium speakers in at times depending on what they take in on trade of course they may be higher in price too depending on wattage and application but still used speakers can be a good buy if you have a source for them.

[VacuumVoodoo]

Why bother, you ask? It's what inquisitive minds do to discover and learn. Just like when you take apart grandpas pocket watch to see what makes it tick.

[doctorx]

There are a lot of alnico speakers out there in old fifties and sixties console hi fi setups, sometimes these can sound good. Back in those days there weren't separate designs for guitar and hi fi, Leo just used whatever the speaker manufacturer offered.

Amps like Silvertone and Kay and so forth used speaker brands like Fisher instead of Jensen and Oxford.

These might be improved by doping the edges with rubber cement, or places like Orange County Speaker repair can recone them with a better sounding, guitar oriented speaker cone. I have a couple of these I am going to do that with.

[jh45gun]

Why bother, you ask? It's what inquisitive minds do to discover and learn. Just like when you take apart grandpas pocket watch to see what makes it tick.

Last thing I took apart to see how it ticked was mom's old pedal sewing machine when I was a kid I learned then some things are best left alone. :nono

[oxydon]

when I was a kid I learned then some things are best left alone. :nono Like this topic :NUTS, i mean no misrespect but it's not good to be negative, if the topic doesn't interest you ...

Now i have too ElCheapo speakers one 12" (the one i actually want to improve and use) and a small 8" one that i will use for experimentation, so i try things in the small and apply what works on the big one.
The small one came with a torn cone so i removed it, and i figured out the coil was broken too, then i measured the length of the wire (6 meters) and thrown it away, now i only have the structure and the magnet.
First thing to do is to build a voice coil using what we have learned until now:
1 - coil always in the magnetic field means more spl.
2 - coil partially leaves the magnetic field in the higher peaks means more speaker distortion (i want that).
from 1 and 2 my idea is to wire the coil in two parts, then i will have one part to be always inside and the other to be halfway outside and then to be easily outside the field in the higher "pushes".

Second constraint is to have the final coil having 8 Ohms DC resistance, i have no measuring instrument that has enough precision to measure that, i remember the old coil was 6 meters long but i am not sure i can get the exact diameter, if someone has an idea ...

after that i will make a paper cone, the aim is to design a cone that breaks off easily so i can have the speaker "cry" at lower volumes, i wire the voice coil now and we will talk about the cone later.
The dust cap in the 12" is large and too stiff, i absolutely need to replace it since i play heavy stuff and too much brightness is not good for me, even for the solos btw.

[phsyconoodler]

I love the spirit of do-it-yourself too.I want to learn to recone speakers and what those little differences make,but material on the subject is really limited and recone kits are really hard to find.At least I am having trouble locating parts and info on the subect.
Does anyone have some links on where a guy can get more information?

[oxydon]

We will try to make our own straight cones, i have seen someone successfully repairing a torn celestion cone with toilet paper and glue, i think this idea can be extended to making the whole cone from scratch, you can cut a pattern in thin paper and glue the toilet paper pieces on it afterwards, to maximise cone breakup, i suggest wetting the paper first and letting it dry slowly, i will try this tonight and post some pictures later, i can try this directly in the 12" (its orriginal cone sucks // too stiff).
For the coil, i havent made it yet, i still don't know how to make it be exactly 8 Ohms.

[rockon1]

We will try to make our own straight cones, i have seen someone successfully repairing a torn celestion cone with toilet paper and glue, i think this idea can be extended to making the whole cone from scratch, you can cut a pattern in thin paper and glue the toilet paper pieces on it afterwards, to maximise cone breakup, i suggest wetting the paper first and letting it dry slowly, i will try this tonight and post some pictures later, i can try this directly in the 12" (its orriginal cone sucks // too stiff).
For the coil, i havent made it yet, i still don't know how to make it be exactly 8 Ohms.

I applaud your determination but I doubt you will succeed in making anything "better" with glued up bits of toilet paper than even a cheap speaker would have.
I would try to find speaker cone material at least. At the worst is should prove interesting though... Heck from scratch I'd be happy if the speaker made noise of any kind!

As for impedance enough legnth of wire of the right gauge measured with a multi meter would get you to the right resistance . 6-7 ohms resistance is approximately 8 ohms impedance. Bob

[oxydon]

I think you are right, but since i already started, ...at the moment i glued up four well cut pieces of standard printer paper to form the rough shape of a cone, then i glued uppon it smaller pieces of a thinner paper to round the shapes, then i cut the small and the big circles and it started to "look like" a speaker cone, after that i randomly folded the paper a million times to make it weaker and to have it easily breakoff at high pressure (initial design goal), now i am waiting for it to dry completely, then i will start the toilet paper work to finish the work (and have a nicer surface), when everything will be finished i will paint the whole thing black, i believe the paint will give it the final touch (a bit more stiffness, a better surface, better color, better durability), if in the end it is not yet enough i will keep adding layers of varnish until it's okay, ... i will post pictures and sound clips in all cases, likewise nobody will ever make the same mistakes that i.
more later ;)