Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: daveh on November 19, 2009, 12:31:43 AM

Title: Cheap speaker source
Post by: daveh on November 19, 2009, 12:31:43 AM
I'm looking for the cheapest possible speakers for small LM386 and TDA2003 based amps. 4 inch or so for the 386 and 6 or 8 inch for the 2003. I found some great deals at http://www.electronix.com/catalog/default.php/cPath/362_363
but they don't have sensitivity specs. Anyone know of cheap, good sounding speakers for low power amps?

thanks!
Title: Re: Cheap speaker source
Post by: J M Fahey on November 19, 2009, 07:09:32 AM
Quotethey don't have sensitivity specs
And for a very good reason, they're abismal, in the low 80's.
The first page is full of tweeters and midrange ones, the second with foam edge woofers, which *require* 30 to 150W amplifiers.
The one that *might* be somewhat usable is the http://www.electronix.com/catalog/product_info.php/cPath/362_364/products_id/13518
Buy two (to get 4 ohms total) and build a "micro-Twin"
Your best bet is a salvaged TV or old car radio speaker.
Juan Manuel Fahey
Title: Re: Cheap speaker source
Post by: joecool85 on November 19, 2009, 11:11:33 AM
Quote from: J M Fahey on November 19, 2009, 07:09:32 AM
Quotethey don't have sensitivity specs
And for a very good reason, they're abismal, in the low 80's.
The first page is full of tweeters and midrange ones, the second with foam edge woofers, which *require* 30 to 150W amplifiers.
The one that *might* be somewhat usable is the http://www.electronix.com/catalog/product_info.php/cPath/362_364/products_id/13518
Buy two (to get 4 ohms total) and build a "micro-Twin"
Your best bet is a salvaged TV or old car radio speaker.
Juan Manuel Fahey

Car radio not so great, old TV or stereo speaker, good way to go.
Title: Re: Cheap speaker source
Post by: darwindeathcat on November 19, 2009, 01:26:36 PM
The best cheap 4" speaker you can find relatively easily for an lm386 amp will come from an old tape player. I'm not talking about a boombox, I'm talking about those flatish rectangular ones that your teacher had when you were in grade-school. You know, the kind that only plays tapes, and has no radio or anything. Get an old one. The older the better. You can almost always find them at the Goodwill or at Salvation, usually for less than $5. GREAT little speakers in those older ones. This is what I used for my own noisy cricket, and it sounds really good. Far better than with the drivers that came out of old computer speakers and intercoms that I also tried. I never tried old tv speakers, so they might also be good, but that seems like a bigger hassle unless you happen to have a crappy old tv sitting around.
Title: Re: Cheap speaker source
Post by: daveh on November 19, 2009, 05:03:15 PM
Thanks for the input. We build a lot of these small amps and I'd like to find a source of speakers I could buy. Even something like the speakers used in the cheapest giutar amps. I see Fenders, Rogues, etc for $50 or less new. Their speakers sound great with a little 386 amp, but does anyone know where to get them or some like them?

If a commercial amp sells for 50 bucks, they must get the speakers for $5 or so, maybe less.

thanks!
Title: Re: Cheap speaker source
Post by: joecool85 on November 20, 2009, 06:08:36 AM
Quote from: daveh on November 19, 2009, 05:03:15 PM
Thanks for the input. We build a lot of these small amps and I'd like to find a source of speakers I could buy. Even something like the speakers used in the cheapest giutar amps. I see Fenders, Rogues, etc for $50 or less new. Their speakers sound great with a little 386 amp, but does anyone know where to get them or some like them?

If a commercial amp sells for 50 bucks, they must get the speakers for $5 or so, maybe less.

thanks!

Not sure where they are getting them from.  Just a heads up, if you are building "a lot of these small amps" you should be careful what schematic you are using.  You'll run into legal issues if you are using one directly off someone's site without their permission.  Good luck with it though.
Title: Re: Cheap speaker source
Post by: J M Fahey on November 20, 2009, 02:05:01 PM
QuoteEven something like the speakers used in the cheapest giutar amps. I see Fenders, Rogues, etc for $50 or less new. Their speakers sound great with a little 386 amp, but does anyone know where to get them or some like them?
You bet they do, they are *guitar* speakers. But they certainly come from a *massive* OEM factory in China with minimum orders in the thousands, who supplies everybody, just as Eminence does in the US with medium price guitar speakers.
QuoteIf a commercial amp sells for 50 bucks, they must get the speakers for $5 or so, maybe less.
I'm sure of that. Problem is, you won't find them in "regular" audio retailers, who cater to car audio, home theater and other similar big markets.
A Jensen Mod 5" or 6" or similar would be an excellent choice, and much better than what most use , but their $24 or $30 price goes through the roof.
Download their spec sheets and take a hard good look at their pictures, that's what you need: small light voice coils, thin all-paper cones (no foam), reasonable magnets (72mm to 86 mm diameter).
Google "jensen mod guitar speaker" in "Images".
From what you posted, the only reasonable one is what I indicated before, a generic speaker : 6", 3/4inch/19mm voice coil, light cone, unfortunately foam surround and meagre 60mm magnet.
I can buy them in lots of 200 for a very low cost, yet I prefer to roll my own.
Try those and post your results, and even better, some MP3s.
Title: Re: Cheap speaker source
Post by: rowdy_riemer on November 20, 2009, 04:29:51 PM
I love my Mod 8. Of course, then again, I do not have a tremendous amount of experience with guitar speakers or amps. I was using a general purpose audio woofer to test some of my amp projects. I knew I needed a real guitar amp speaker, so I broke down and bought a Mod 8. There is a world of difference, and it really wasn't that much $$$ (especially for guitar speakers).  However, the old intercom speaker I tried before wasn't too bad. There was a small cone in the middle of the driver that I removed to kill some of the highs. I think the Mac Ruby project(runoffgroove.com) used a Mod 6.
Title: Re: Cheap speaker source
Post by: rowdy_riemer on November 20, 2009, 04:39:02 PM
Quote from: J M Fahey on November 20, 2009, 02:05:01 PM
QuoteEven something like the speakers used in the cheapest giutar amps. I see Fenders, Rogues, etc for $50 or less new. Their speakers sound great with a little 386 amp, but does anyone know where to get them or some like them?
You bet they do, they are *guitar* speakers. But they certainly come from a *massive* OEM factory in China with minimum orders in the thousands, who supplies everybody, just as Eminence does in the US with medium price guitar speakers.
QuoteIf a commercial amp sells for 50 bucks, they must get the speakers for $5 or so, maybe less.
I'm sure of that. Problem is, you won't find them in "regular" audio retailers, who cater to car audio, home theater and other similar big markets.
A Jensen Mod 5" or 6" or similar would be an excellent choice, and much better than what most use , but their $24 or $30 price goes through the roof.
Download their spec sheets and take a hard good look at their pictures, that's what you need: small light voice coils, thin all-paper cones (no foam), reasonable magnets (72mm to 86 mm diameter).
Google "jensen mod guitar speaker" in "Images".
From what you posted, the only reasonable one is what I indicated before, a generic speaker : 6", 3/4inch/19mm voice coil, light cone, unfortunately foam surround and meagre 60mm magnet.
I can buy them in lots of 200 for a very low cost, yet I prefer to roll my own.
Try those and post your results, and even better, some MP3s.

You roll your own speakers? That sounds pretty cool.
Title: Re: Cheap speaker source
Post by: J M Fahey on November 21, 2009, 09:07:03 AM
Yes, it *is* cool 8|, yet very expensive and complicated just to start.
The work is about 350% metallurgical and only 15% acoustic or electronic or whatever.
I had to buy a lathe to turn magnet "disks" and center cores, of course a supplier of raw disks and iron round bar stock (it comes in "easy to handle" 20 foot lenghts), somebody to cut 18ga sheet steel disks which would late become speaker frames, a car parts factory that had the required huge hydraulic presses, raw unmagnetized ceramics, spare cones and suspensions, had to make a voice-coil winding device, the works.
Yet I *had* to do it because 35 years ago in Argentina there were *no* guitar speakers, at any price. Period.
In the long run, it was a smart investment and payed itself over and over.
Today cheap chinese imports are killing every amp maker, not only here but everywhere.
I can still hold my own because of house-produced speakers, transformers, PCBs, chassis and panels, even metallic corner protectors and, of course, cabinets.
*Every* machine I bought, many of them causing comments such as "you are absolutely crazy" has paid itself.
Now I'm trying to set up a cnc router table to turn out cabinet parts ready-to-assemble and would love to build a Potdevin type industrial Tolex glueing machine.
Either one of these will become next year's project.
Title: Re: Cheap speaker source
Post by: rowdy_riemer on November 23, 2009, 09:50:26 AM
Damn. Sounds pretty bad ass, dude.
Title: Re: Cheap speaker source
Post by: awdman on November 24, 2009, 09:27:46 PM
very nice :tu: