How many watts?

[tat2bass 10+ year member]

My question is this...if an amp is rated for say 100wx4 at 4ohms(RMS) at 14.4V, how do they set the gains on the amp when testing to get these power levels? Do they just crank the gain adjustment all the way up and test max rms power regardless of whether the signal is clipped or complete crap? Or do they use the test signal and adjust the gain to the highest level before clipping indicating the highest safe daily level it could be run at and test the power at that point? I havent been able to find a definitive answer on this. And this same concept would apply to amps for subs also. I am getting ready to start building an SQL oriented system and want the most clean power I can get but want to make sure that I properly balance and match up all of my components. Thanks

Click to read more...

 

[jsluss17 10+ year member]

i also wanna know this

 

[chillin 10+ year member]

if you look at the amp specs it should tell you what level of distortion was being reached at said wattage. some will be

Zapco - Reference

Soundstream - XXX Amplifiers

 

[tat2bass 10+ year member]

Ok, I'm looking at doing a fairly low budget SQL build. I'm looking at doing the MB Quart ONYX4.125 which is rated at 125x4 at 4 ohms going to some Massive Audio RK6 which are rated at 120. I work in communications and have easy access to an oscilloscope so I will be using that to set everything. Is there a way to tell how many watts or how much power I am pushing after I set all of my gains correctly without clipping? I'm not exactly sure on how the THD at certain power levels reflects clipping or signal distortion. If I'm thinking correctly if it is rated for say 100x4 at 4 Ohms and the THD is less than 1% should I expect to see at least 99watts when gains are correctly set?

 

[LosIsATool 5,000+ posts]

You clamp it after you set the gain to find out what its making

 

[tat2bass 10+ year member]

Just with a standard DMM? I'm guessing there is no way of being sure before purchasing and installing an amp of what power it will put out when properly tuned and all? If someone else has the same amp could I expect reasonably close results if their's is tuned correctly or would that be to dependent on electrical? I'm looking at spending about $1000 on equipment and $1000 on install materials. Doing the install myself but planning on doing everything properly with excellend electrical and deadening and all. So I am planning on my electrical being more beefed up than most so that I get the most out of my equipment efficiently as possible.

 

[LosIsATool 5,000+ posts]

Just with a standard DMM? I'm guessing there is no way of being sure before purchasing and installing an amp of what power it will put out when properly tuned and all? If someone else has the same amp could I expect reasonably close results if their's is tuned correctly or would that be to dependent on electrical? I'm looking at spending about $1000 on equipment and $1000 on install materials. Doing the install myself but planning on doing everything properly with excellend electrical and deadening and all. So I am planning on my electrical being more beefed up than most so that I get the most out of my equipment efficiently as possible.

A true rms clamp meter and a DMM.

 

[maylar 10+ year member]

Ok, I'm looking at doing a fairly low budget SQL build. I'm looking at doing the MB Quart ONYX4.125 which is rated at 125x4 at 4 ohms going to some Massive Audio RK6 which are rated at 120. I work in communications and have easy access to an oscilloscope so I will be using that to set everything. Is there a way to tell how many watts or how much power I am pushing after I set all of my gains correctly without clipping? I'm not exactly sure on how the THD at certain power levels reflects clipping or signal distortion. If I'm thinking correctly if it is rated for say 100x4 at 4 Ohms and the THD is less than 1% should I expect to see at least 99watts when gains are correctly set?

Why does it matter how much power you're actually getting? If you trust the amp manufacturer and you adjust gains for no clipping you get what you get.

Don't expect a 4 channel amp to give 4 X whatever RMS with all 4 channels driven by a sine wave. It's not realistic in the real world - we don't listen to sine waves.

 

[tat2bass 10+ year member]

I don't know, maybe because how much power I'm actually getting is probably the most important thing. I didn't know that we didn't listen to sine waves. That is what I like to listen to. I'm not expecting an amp to put out 4 by whatever RMS with a perfect sine wave all the time. I do understand there are a lot of variables that change with install, electrical, etc. But do manufacturers test the equipment to get said power figures with a sine wave or music? If they are using a perfect sine wave the numbers will look a lot better. Why I am asking is that I don't want to purchase an amp based off of manufacturers numbers and then get it, and in a real world application with adjusting the gains and tuning and playing music my power levels be considerably less than what was stated. So again, if they start with a perfect sine wave and amplify it and test the rated power andTHD off of that, the numbers will be considerably higher and better looking than it would be in a real world configuration.

 

[groundpound4200 5,000+ posts]

You're overthinking this way too much.....

 

[IonRL205 10+ year member]

I don't know, maybe because how much power I'm actually getting is probably the most important thing. I didn't know that we didn't listen to sine waves. That is what I like to listen to. I'm not expecting an amp to put out 4 by whatever RMS with a perfect sine wave all the time. I do understand there are a lot of variables that change with install, electrical, etc. But do manufacturers test the equipment to get said power figures with a sine wave or music? If they are using a perfect sine wave the numbers will look a lot better. Why I am asking is that I don't want to purchase an amp based off of manufacturers numbers and then get it, and in a real world application with adjusting the gains and tuning and playing music my power levels be considerably less than what was stated. So again, if they start with a perfect sine wave and amplify it and test the rated power andTHD off of that, the numbers will be considerably higher and better looking than it would be in a real world configuration.

You would see that power with perfect voltage and playing a sine wave, but since you will be playing music, the power will not be a constant amount since music changes and all songs are different; you'll be putting out less power than what it stated.

You're caring way too much about this. Just set your gains with a test tone and a DMM and be done.

 

[CrossFired 10+ year member]

Your tweaking! Just install it and enjoy it. Most likely the manufacturers don't even test the amp, as the designer will know it's RMS output by design. And it's not like your going to listen to a perfect sign wave.

I don't know, maybe because how much power I'm actually getting is probably the most important thing. I didn't know that we didn't listen to sine waves. That is what I like to listen to. I'm not expecting an amp to put out 4 by whatever RMS with a perfect sine wave all the time. I do understand there are a lot of variables that change with install, electrical, etc. But do manufacturers test the equipment to get said power figures with a sine wave or music? If they are using a perfect sine wave the numbers will look a lot better. Why I am asking is that I don't want to purchase an amp based off of manufacturers numbers and then get it, and in a real world application with adjusting the gains and tuning and playing music my power levels be considerably less than what was stated. So again, if they start with a perfect sine wave and amplify it and test the rated power andTHD off of that, the numbers will be considerably higher and better looking than it would be in a real world configuration.

 

[maylar 10+ year member]

There is an industry standard that reputable companies use to rate the power output of their amps. It's CEA2006. Unfortunately you have to buy it if you want to really see how they do it -

Car Amplifier Standard

There have been attempts to do this in the past as well, example the Institute of High Fidelity (IHF) came up with a measurement system that took real world conditions into account noting that music programming has a high peak-to-average ratio and an RMS continuous measurement was unfair to the amp.

You're overthinking this way too much.....

^^ This

 

[twistedchild420 5,000+ posts]

The main question is what does your voltage drop down to when its raining? Answer that and I can better help you.

 

[Bettr n' Revrse 5,000+ posts]

You're overthinking this way too much.....

Yep