paid too much for speakers, tech question

[Francesco Rizzo]

Umm.. I overpaid for some speakers and umm can't return them. Anway, they're not that bad witht he exception that the sub won't hit below 250 hrz, per specs off box. I wanted to obtain this sub 250 hrz capability and I think the reason it's not happening is because the 8 inch sub is junk. I was wondering if I could trade it out with a different sub? I know 8 ohms and 4 ohms might not be so good to mix, but I can get a cheap 8 inch sub that works better and not be throwing away so much money. If the sub is 8 ohms and I throw a 4 ohms sub does this mean I double the watts to that 4 ohms sub.. and I'm affraid the amp might not be stable for 4 ohms.. so what does that mean and what would happen? what if I add a 4 ohm resistance from radioshack parallel to the 4 ohms speaker? will that help to not set things ablaze? what if I change all the lil speakers to 4 ohms too... I realy don't care anymore so I just kinda didn't want set my house on fire.

thanks for any help you might have to offer and no matter what kids might tell you in a parking lot, and no matter how much the "seller" of the anything might list them off their home page... it's all a lie. best part is I knew better and smelled the bs a mile away, but sound systems and speakers are my crack, yo :sad1:

[Francesco Rizzo]

correction, I meant seriers

[Francesco Rizzo]

ok, Ididn't like what I ready.. I'll double the amps and overheat the amp.. so anyone know about resistors.. Radio shack sells these 8 ohms resisters.. what id I connect them in parrell with one another in line as a series with the speakers :confused:

[JAFO]

First here is a link to a parallel & series calculator: http://www.the12volt.com/caraudio/boxcalcs.asp#par

Now household stereo systems generally use 8 ohm speakers and car audio generally uses 4 ohm speakers (there are some exceptions, dual voice coil for instance, but this is in general).

Parallel Circuit: All positive leads of two or more speakers connected together and all negative leads connected together.

If you take two 8 ohm speakers and connect them together in parallel your load on the amplifier will be 4 ohms. The resistance is cut in half. Similarly if two 4 ohms speakers are wired in parallel the resistance will equal 2 ohms.

Series Circuit: Connecting the positive speaker output of an amplifier channel to the positive terminal of speaker # 1 , connecting the negative terminal of # 1 to the positive terminal of speaker # 2, and the negative terminal of # 2 to the negative output of the same amplifier channel is a series connection.

If you take two 8 ohm speakers and connect them together in series your load on the amplifier will be 16 ohms of resistance. Two 4 ohm speakers would give 8 ohms in resistance. In a series the resistance is doubled.

So to answer your question, yes if you have a 4 ohm speaker and connect a 4 ohm resistor in series the result will be a 8 ohm load on the amplifier. Now if you mix speakers who's resistance is not the same use the calculator above and you will see that a 8 ohm and a 4 ohm speaker connected in parallel would have a 2.666 ohm load. In Series it would give a 12 ohm load.

As far as what your amplifier can handle read the owners manual or look for specific information about that model on the Internet. If you deside to go with a lower resistance than stock your amp may run hot leading to clipping - amp gets too hot and temporarely turns off to avoid damage. If your amps are so hot that you can't touch it there is a problem.

[Hotsauce]

I have never seen a car amp that wasn't stable into 4 ohms. at 2 ohms or less, some will draw too much current and overheat.

If the sub is wired seperatly you can switch it, but if its a woofer in a 3 way speaker, substituting a woofer of different ohms wil change the crossover point.

Clipping is not the amp turning off, clipping is the signal going DC at the peaks.

Give the make and model of the speaker and amp, and I can give a more accurate answer.

John C.