Ohms and Bridging Confusion :(
In reality, you could wire the sub to 8 ohms, run the amp bridged, so it will in fact see 8 ohm load. The manual says the amp puts out less at 8 ohms, but in this case you can jack up the gains higher to push the amp harder, so it will reach it's full potential no matter what, and then some(clipping). So try that, and set the gains higher to the point of distortion at highest listening volume, and then you can reduce it a notch so it does not distort.
Trust me this way your amp will work to it's full power, as you will force it sort of speak. Higher impedance is underrated
and the rms ratings at different loads are more of a marker to the correct gain setting to your head unit's voltage. If you up the impedance you can jack up the gains to get the amp to convert the demanded current, thus getting your desired wattage. At higher impedance, your amp will also have better control(damping) of the woofer, so you can push the amp harder with less distortion from that perspective. It does not need to get any more technical than this 
Do that and thank me later. ENJOY!!!!!!!!!
Trust me this way your amp will work to it's full power, as you will force it sort of speak. Higher impedance is underrated
and the rms ratings at different loads are more of a marker to the correct gain setting to your head unit's voltage. If you up the impedance you can jack up the gains to get the amp to convert the demanded current, thus getting your desired wattage. At higher impedance, your amp will also have better control(damping) of the woofer, so you can push the amp harder with less distortion from that perspective. It does not need to get any more technical than this Do that and thank me later. ENJOY!!!!!!!!!
Last edited by Sasha; Oct 25, 2008 at 02:10 AM.
Oh, and make sure your Low Pass Filter is set at 80hz or lower, and you can use subsonic filter if the amp has one, and set it at 20hz, cause that will also take the strain off your not so powerful amp, and rededicate the power you do have towards the more important frequency between 20hz and 80hz, so you will force all that power into that frequency band. If subsonic feature is not there, then forget about it. Peace!!!
50 Watt CAFz'r
Joined: May 2007
Posts: 384
Higher impedance is underrated and the rms ratings at different loads are more of a marker to the correct gain setting to your head unit's voltage. If you up the impedance you can jack up the gains to get the amp to convert the demanded current, thus getting your desired wattage. At higher impedance, your amp will also have better control(damping) of the woofer, so you can push the amp harder with less distortion from that perspective.
If you have the sub hooked up in a 8 ohm configuration and you hook it up to a briged 2 channel amp the amp will see a 4 ohm load not 8.
that information is incorrect. the gain is used to match the output of the head unit to maximize the out put of the amp.The impedance directly determines how much power an amp is going to make. a 500 watt amp is still a 500 watt amp no matter what the gain is at. If you put more of a load and crank the gain you will still get a crap load of clipping. more than 5% clipping is bad. You should set the gains using an oscilloscope if one is handy cause most of the time you can't hear the clipping until it's too late.
that information is incorrect. the gain is used to match the output of the head unit to maximize the out put of the amp.The impedance directly determines how much power an amp is going to make. a 500 watt amp is still a 500 watt amp no matter what the gain is at. If you put more of a load and crank the gain you will still get a crap load of clipping. more than 5% clipping is bad. You should set the gains using an oscilloscope if one is handy cause most of the time you can't hear the clipping until it's too late.
^^^ I agree with some and disagree with some. All depends how you look at it. Makes no difference now, he got it going.
I dont want to get into a long discussion on the gains and lalala, but companies make their amps with reliability as a main factor, cause nobody wants to fix stuff on warranty for free, so it is safe to say that vast number of amps only put out their rated power when overjacked, and the customer is lead to believe what you've said above, thus using the amp to partial potential, so reliability goes way up. So, I will give you half the credit, and take the other half, cause we are both right on some accounts. How is that? At the end, it is your ears that will help you tune the sound, not oscilloscope. I dont want to get into technical knowledge exchange, which goes nowhere, and takes up our time.
....And I was not referring to "overdriving" the amp. If amp is rated 1000 watts at 1 ohm, and 700 watts at 2 ohms, you can expect it to do 1000 watts at 2 ohms too, it is dependent on how you set those gains, some of it depends on how regulated the amp in question is, cause all amps are regulated to a degree. Most amps on the market are light on regulation, and you can do a lot with them. So, sometimes you gotta get your nose out of the manual, and start thinking physics and common sense. Man, I dont want to talk about it. You win. yada yada yada...
....And I was not referring to "overdriving" the amp. If amp is rated 1000 watts at 1 ohm, and 700 watts at 2 ohms, you can expect it to do 1000 watts at 2 ohms too, it is dependent on how you set those gains, some of it depends on how regulated the amp in question is, cause all amps are regulated to a degree. Most amps on the market are light on regulation, and you can do a lot with them. So, sometimes you gotta get your nose out of the manual, and start thinking physics and common sense. Man, I dont want to talk about it. You win. yada yada yada...
Last edited by Sasha; Oct 30, 2008 at 04:57 AM.
Good to hear. And by the way, all that info I gave you was not wrong at all, but it seems it was open to misinterpretation, or maybe even misunderstanding. I should perhaps choose my wording better, as I dont want to explain myself so much, and not even covering all misunderstood areas.
