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Current Problems with speakers... Answered

Hey guys, I've uploaded some pictures of my problem.

What I have here is an attempt to add bass to my speakers - I'm a newb, so this isn't going so well. The music is comeing from an iDock, and is being routed in parallel to a set of computer speakers. The right speaker has volume & tone knob, the left is simply plugged into the right.

I unplugged the left speaker, took the circuitry out, and connected its input & output to a larger bass speaker - quickly was I suprised with a smoking capacitor (lol how healthy!) so... what should I do, simply add a resistor?

Edit: Note the resistor (brown red red = 12k? or 1.2k?) is only in series with the LED and is not affecting the bass speaker. I am just wondering how a bass speaker could draw MORE amperage than the small speaker without any circuitry?


Low frequencies are much "quieter" than higher frequencies, so bass speakers need much more power to make the same amount of "noise". They have thicker wire, bigger magnets and take more current.
You might want an amplifier to run your bass units.


Yeah I figured... I wanted to make my own. It was working well with the 1 ampere (the sound quality anyways). I don't have the knowledge to make my own crossover i dont think, so I figured just hooking it up would be the next best thing.


8 years ago

Without knowing for sure what your circuit board does, I'm guessing it's just the incoming power filter / power indicator light for the external speakers. The resistor is probably just current-limiting for the LED indicator (no effect on the audio circuitry.) Is there an additional amplifier board in the right speaker?

Each speaker has a specific impedance, and the amp / speaker combination isn't random--it's designed.

So if you change the load significantly, you'll have problems. For instance, if you connected a 4 ohm speaker to an amp that's expecting a 16 ohm load, then it will draw more current. Not to mention that an unbalanced load might be an issue, too (if the two speakers are different.)

And transistor-based amps really don't like a load that's too large... (smaller impedance/resistance value = more current = larger load.)

> incoming power filter / power indicator light for the external speakers
.  I agree. It doesn't look like any crossover I've seen (no inductor and I've never seen an LED on one), but it does look like a power filter with indicator.

Ok thats what I suspected - I'm pretty sure however the original left speaker was 4 ohms (but am not positive - doesn't specify either). And that the larger bass was 2 Ohm, but I haven't taken that apart to look either! What would a crossover do?

I was just going to (somehow) add 2ohms in series with the bass and see if that does anything.

Find a second, identical speaker, and wire it in series. Or replace it with a single 4 ohm speaker.

2 ohm power resistors can be found, but that's resistive load, not an inductive one. It may work, but the inductive load of a speak isn't constant, it varies with frequency. Better to use an "L-pad" than a single resistor, if that's your plan (L-pads don't need to be adjustable, so a rheostat isn't necessary.)

Resistive attenuators don't receive very high marks from "audiophiles."

Or just find a powered Sub; forget running it off the tiny computer speaker amp...

(Also, a smoking capacitor has either already failed, or is about to...)

www.prestonelectronics.com/audio/Impedance.htm may help to explain impedance on speakers.  Plugging in mismatched speakers may cause some problems. I think you may need a crossover circuit of some sort if you want to really get the bass going to a bigger cabinet.  You might need to consult the audiophiles here.

The audiophiles are probably cranking up their bang&olfsen amps connected to their Bose headphones tuning out the world...for everyone else, we have this.

A crossover circuit filters out the high frequencies or low depending on if it is high-pass or low-pass and the appropriate one will send the signal over to the dedicated subwoofer speaker or hi-freq tweeter for best sound.