adam112
New member
Hi i wondered if anybody could tell me if a 4x45 watt head unit would power a amp, sub and 220 watt 6x9's ok? if not what output head unit would you need, thanks
Adam112
Adam112
Output for sub amp etc
- Thread starter adam112
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Output for sub amp etc
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The power of the head has no relation to how much amplifier power you can use. You're just gonna need a pre-amp RCA output at line-level to drive the amp.
Looking at the power ratings on most car audio is a minefield, they all want to rate things differently. The only true value to work with is the RMS (Root Mean Square) rating, and even then this should be given with a percentage "total harmonic distortion" of less than 0.03% over a bandwidth of 30Hz to 20KHz, to give a true representation of what the equipment will do.
The sound pressure level delivered from your system will then depend on the efficiency of the drivers (speakers) which you are using. This is measures as db@1W/1m. This figure will usually sound much higher than you would expect. The concert PA's which I build usually have ratings of anywhere between 94db@1W/1M and 103db@1W/1M.
I would normally use 20% to 25% more amplifier power (RMS) than I had speaker rating (RMS)........
But only because I have trained ears. I'm likely to hear it before a problem occurs. You will regularly hear that this is the best way to blow speakers.....If you use you're head it isn't, if you think distortion means that its loud, then you're already in trouble!
Driving speakers with underpowered amplifiers often leads to the amplifier delivering too high a current, rather than the higher voltage of a bigger better quality amp......This is what destroys speaker coils without warning.
If I were you I'd look for quality gear that readily states its RMS power values, which may seem much lower than other figures quoted as "Program Power" "Peak Music Power" etc. When you've found a good range of equipment you're interested in, buy some speakers with around the same rating as what you're going to drive them with, be that the head or a seperate amp. Seperate amps for the main stereo and sub with a seperate active cross-over will usually give the best results.
Better stop, before it turns into an open university lecture series but it might help......
CP
Looking at the power ratings on most car audio is a minefield, they all want to rate things differently. The only true value to work with is the RMS (Root Mean Square) rating, and even then this should be given with a percentage "total harmonic distortion" of less than 0.03% over a bandwidth of 30Hz to 20KHz, to give a true representation of what the equipment will do.
The sound pressure level delivered from your system will then depend on the efficiency of the drivers (speakers) which you are using. This is measures as db@1W/1m. This figure will usually sound much higher than you would expect. The concert PA's which I build usually have ratings of anywhere between 94db@1W/1M and 103db@1W/1M.
I would normally use 20% to 25% more amplifier power (RMS) than I had speaker rating (RMS)........
But only because I have trained ears. I'm likely to hear it before a problem occurs. You will regularly hear that this is the best way to blow speakers.....If you use you're head it isn't, if you think distortion means that its loud, then you're already in trouble!
Driving speakers with underpowered amplifiers often leads to the amplifier delivering too high a current, rather than the higher voltage of a bigger better quality amp......This is what destroys speaker coils without warning.
If I were you I'd look for quality gear that readily states its RMS power values, which may seem much lower than other figures quoted as "Program Power" "Peak Music Power" etc. When you've found a good range of equipment you're interested in, buy some speakers with around the same rating as what you're going to drive them with, be that the head or a seperate amp. Seperate amps for the main stereo and sub with a seperate active cross-over will usually give the best results.
Better stop, before it turns into an open university lecture series but it might help......
CP
