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Old 10-04-2012, 10:19 PM - Thread Starter
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My specs say 4 and 8 ohms > 80 watts. Would 4 ohms be 2x the watts of 8 ohms? Amp is Nad C356.
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Old 10-05-2012, 12:09 AM
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I just looked a spec sheet for that amp, doesn't say that. Read again.

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-05-2012, 06:16 AM - Thread Starter
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Originally Posted by lovinthehd View Post

I just looked a spec sheet for that amp, doesn't say that. Read again.

question revised.
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Old 10-05-2012, 11:03 PM
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Originally Posted by flargosa View Post

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Originally Posted by lovinthehd View Post

I just looked a spec sheet for that amp, doesn't say that. Read again.

question revised.

Yeah, but you're still missing what they're saying.....at the spec'd THD of .009%. Look at the output for dynamic, looks like a decent 4ohm output (at 8ohm 145, at 4 ohm 220, at 2 ohm 290).

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-06-2012, 08:37 PM
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Originally Posted by flargosa View Post

My specs say 4 and 8 ohms > 80 watts. Would 4 ohms be 2x the watts of 8 ohms? Amp is Nad C356.

There is no WPC standard the manufactures stick to.

Your amp is a stereo amp.

Into 1 channel at 8ohms, it'll do 80wpc, continuous.

Into 2 channels at 4ohms it'll do 80wpc, continuous.
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Old 10-06-2012, 08:57 PM
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Originally Posted by NorCalJason View Post

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Originally Posted by flargosa View Post

My specs say 4 and 8 ohms > 80 watts. Would 4 ohms be 2x the watts of 8 ohms? Amp is Nad C356.

There is no WPC standard the manufactures stick to.

Your amp is a stereo amp.

Into 1 channel at 8ohms, it'll do 80wpc, continuous.

Into 2 channels at 4ohms it'll do 80wpc, continuous.

Why do you mention stereo amp? What's that got to do with anything in this discussion?

Undoubtedly this amp will do better than 80wpc at 4 ohm. Some amps will do only slightly better than at 8 ohm, the best amps do it at apprx 2x.

The 80wpc spec is for two channels up to .009% THD in any case, they simply don't state a spec for 4ohm for max wpc otherwise except that up to THD of .009% it will do 80wpc. The output at 4ohm will be higher, just not necessarily 2x, 2x is considered more the ideal, not necessarily what all amps can do. The manual does mention a dynamic (as opposed to continuous as the other 80 watt spec), but it will do not quite 2x per the figures I mentioned previously.

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-07-2012, 12:55 AM
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Originally Posted by flargosa View Post

My specs say 4 and 8 ohms > 80 watts. Would 4 ohms be 2x the watts of 8 ohms? Amp is Nad C356.

I did not review the specs. To me the answer is "let me see third party testing" unless I have some reason absolutely to trust an manufacturer's specs. To "double down" appears not to occur in the real world. Maybe the biggest limitation is power supply. Halving the impedance requires doubling the current for any given voltage. As I understand it, strictly speaking, voltage is what speakers respond to, but of course if the amp can't supply the current that ohm's law requires at a particular voltage and impedance, the amp simply won't achieve the required voltage, becuase Ohm's law is, at least for these purposes, a law. Increased distortion follows. Depending on how one defines clipping, the distortion becomes clipping. How all this works in 11 dimensional reality or under string theory is probably of zero importance to us. Like Newtonian physics does not fully describe what's really happening, but for purposes of a pool game, you can treat it as if the balls actually touch each other and thereby transfer force.
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Old 10-07-2012, 09:42 AM
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Originally Posted by lovinthehd View Post

Why do you mention stereo amp? What's that got to do with anything in this discussion?

NAD rates the amp MONO at 8ohms and STEREO into 4ohms.

What's your problem dude?
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Undoubtedly this amp will do better than 80wpc at 4 ohm.

Yes, but how much? 83watts? 82? If NAD only rates it for 80wpc continuous... That's probably what it does.
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Originally Posted by lovinthehd View Post

The output at 4ohm will be higher, just not necessarily 2x, 2x is considered more the ideal, not necessarily what all amps can do.

Very few amps actually output TWICE the rated power into 4ohms. I don't even understand why you bring this up... I've already posted the answer to the OP's question.

flargosa asked what his amp was rated at.

I provided NAD's answer from their own manual:

Into 1 channel at 8ohms, it'll do 80wpc, continuous.

Into 2 channels at 4ohms it'll do 80wpc, continuous.

Why is it rated only 80 watts mono? I dunno. Why can't it do 80 watts into 2 channels at 8ohms? I dunno. Why does it only push out 80watts x 2 in a 4ohm load? I dunno.

It just doesn't seem like a very robust amplifier.
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Old 10-07-2012, 10:36 AM - Thread Starter
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What do you mean by "1 channel at 8 ohms it'll do 80 watts per channel continuous"? Is that the same as 80 wpc in stereo?
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Originally Posted by NorCalJason View Post

There is no WPC standard the manufactures stick to.
Your amp is a stereo amp.
Into 1 channel at 8ohms, it'll do 80wpc, continuous.
Into 2 channels at 4ohms it'll do 80wpc, continuous.
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Old 10-07-2012, 11:26 AM
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Quote:
Originally Posted by flargosa View Post

What do you mean by "1 channel at 8 ohms it'll do 80 watts per channel continuous"? Is that the same as 80 wpc in stereo?
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Originally Posted by NorCalJason View Post

There is no WPC standard the manufactures stick to.
Your amp is a stereo amp.
Into 1 channel at 8ohms, it'll do 80wpc, continuous.
Into 2 channels at 4ohms it'll do 80wpc, continuous.

Here's the spec sheet http://nadelectronics.com/download.php?100713154539-C_356BEE-DataSheet.pdf|Data%20Sheet%20-%20C%20356BEE%20Stereo%20Integrated%20Amplifier

It says that at either 8 or 4 ohm that this amp will out put in stereo (both channels driven) greater than (that's what the > symbol means) 80w at rated THD (..009%) 20hz-20khz BOTH CHANNELS DRIVEN
It goes on to indicate dynamic power at different levels at 8, 4 and 2 ohm.

If you can't read a spec don't worry about it...

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-07-2012, 04:55 PM
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Originally Posted by lovinthehd View Post

Here's the spec sheet http://nadelectronics.com/download.php?100713154539-C_356BEE-DataSheet.pdf|Data%20Sheet%20-%20C%20356BEE%20Stereo%20Integrated%20Amplifier
It says that at either 8 or 4 ohm that this amp will out put in stereo (both channels driven) greater than (that's what the > symbol means) 80w at rated THD (..009%) 20hz-20khz BOTH CHANNELS DRIVEN
It goes on to indicate dynamic power at different levels at 8, 4 and 2 ohm.
If you can't read a spec don't worry about it...

This is exactly what it says:

"Continuous ouptput power into 8 ohms and 4 ohms (Stereo) > 80 W (at rated THD, 20hz-20khz, both channels driven)"

To me this reads: Continuous output power into 8ohms mono, 4ohms stereo...

Read it however you want...

And again, answering the original question: "what is the rating of my NAD at 4ohms?"

And again, it is: "4ohms, stereo it's 80wpc continuous"
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Old 10-07-2012, 05:30 PM
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Quote:
Originally Posted by NorCalJason View Post

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Originally Posted by lovinthehd View Post

Here's the spec sheet http://nadelectronics.com/download.php?100713154539-C_356BEE-DataSheet.pdf|Data%20Sheet%20-%20C%20356BEE%20Stereo%20Integrated%20Amplifier
It says that at either 8 or 4 ohm that this amp will out put in stereo (both channels driven) greater than (that's what the > symbol means) 80w at rated THD (..009%) 20hz-20khz BOTH CHANNELS DRIVEN
It goes on to indicate dynamic power at different levels at 8, 4 and 2 ohm.
If you can't read a spec don't worry about it...

This is exactly what it says:

"Continuous ouptput power into 8 ohms and 4 ohms (Stereo) > 80 W (at rated THD, 20hz-20khz, both channels driven)"

To me this reads: Continuous output power into 8ohms mono, 4ohms stereo...

Read it however you want...

And again, answering the original question: "what is the rating of my NAD at 4ohms?"

And again, it is: "4ohms, stereo it's 80wpc continuous"

Jason, have it your way if it makes you happy. The spec sheet only says it's greater than 80wpc in 4 or 8 ohm (there's no mention of mono vs stereo, just stereo and they reinforce it by saying both channels driven so have no idea where you're getting the mono thing, please educate us on how you arrive at your interpretation). It's probably not a lot greater than 80 wpc in 4 ohm, but since dynamic is 145 at 8ohm and 220 at 4ohm, so certainly not 2x, altho it's probably greater than 82 or 83 wpc. Unless you bench test, or can find a bench test (I couldn't but didn't look all that hard) then NAD just isn't saying. If you take the ratio of dynamic and apply it to continuous perhaps in neighborhood of 120 wpc at 4ohm, but probably at a higher THD.

OP, you about to put 4 ohm speakers into play and are worried about spl or something? If you really want to know...ask NAD.

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-07-2012, 05:38 PM
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Quote:
Originally Posted by NorCalJason View Post

This is exactly what it says:
"Continuous ouptput power into 8 ohms and 4 ohms (Stereo) > 80 W (at rated THD, 20hz-20khz, both channels driven)"
To me this reads: Continuous output power into 8ohms mono, 4ohms stereo...
Read it however you want...
And again, answering the original question: "what is the rating of my NAD at 4ohms?"
And again, it is: "4ohms, stereo it's 80wpc continuous"

The amplifier will put a minimum of 50% > power into 4 Ohms..
However....
If NAD published the higher 120 watt spec, then the UL/CSA certifying agency would test it @ the higher spec....
And NAD would need to increase the internal build components including power transformer and heat sinking @ significant $ cost in order to pass its higher internal temperature standards when loaded into the higher 4 Ohms power spec..
This way NAD discloses the unit is perfectly capable of driving 4 Ohm loads while keeping the $ cost affordable for a consumer mid-range integrated amplifier..


Just my $0.02.. wink.gif
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Old 10-07-2012, 09:36 PM
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Quote:
Originally Posted by M Code View Post

Quote:
Originally Posted by NorCalJason View Post

This is exactly what it says:
"Continuous ouptput power into 8 ohms and 4 ohms (Stereo) > 80 W (at rated THD, 20hz-20khz, both channels driven)"
To me this reads: Continuous output power into 8ohms mono, 4ohms stereo...
Read it however you want...
And again, answering the original question: "what is the rating of my NAD at 4ohms?"
And again, it is: "4ohms, stereo it's 80wpc continuous"

The amplifier will put a minimum of 50% > power into 4 Ohms..
However....
If NAD published the higher 120 watt spec, then the UL/CSA certifying agency would test it @ the higher spec....
And NAD would need to increase the internal build components including power transformer and heat sinking @ significant $ cost in order to pass its higher internal temperature standards when loaded into the higher 4 Ohms power spec..
This way NAD discloses the unit is perfectly capable of driving 4 Ohm loads while keeping the $ cost affordable for a consumer mid-range integrated amplifier..


Just my $0.02.. wink.gif

Thanks, was wondering why the lower stated spec, didn't think a bit higher THD should keep them from saying something. Didn't know UL had such standards!

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-07-2012, 09:51 PM
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Thanks, was wondering why the lower stated spec, didn't think a bit higher THD should keep them from saying something. Didn't know UL had such standards!

Yup...
UL/CSA takes the brand's advised power output and impedance load specifications and they run a series of bench tests where the internal operating temperatures are monitored..
If certain limits are exceeded the unit does not pass...

These temperature tests are well-known to each brand's design team so they design each component to pass these according to the product's price class and electrical specification yield, as one can imagine upgrading the power transfomer/power supply can raise internal costs significantly..
Especially for a price-point AVR or integrated amplifier.


Just my $0.02... wink.gif
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Old 10-07-2012, 10:06 PM
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Originally Posted by M Code View Post

Quote:
Originally Posted by lovinthehd View Post

Thanks, was wondering why the lower stated spec, didn't think a bit higher THD should keep them from saying something. Didn't know UL had such standards!

Yup...
UL/CSA takes the brand's advised power output and impedance load specifications and they run a series of bench tests where the internal operating temperatures are monitored..
If certain limits are exceeded the unit does not pass...

These temperature tests are well-known to each brand's design team so they design each component to pass these according to the product's price class and electrical specification yield, as one can imagine upgrading the power transfomer/power supply can raise internal costs significantly..
Especially for a price-point AVR or integrated amplifier.


Just my $0.02... wink.gif

Yeah, that would explain some others that get reported as fine with 4ohm but when I look up specs there aren't any for 4 ohm....so if you did drive this 356 at sustained volume for a long time....would it spontaeously combust ? cool.gif

ps Looked up Box Canyon cuz I couldn't place it...but my brother lived in West Hills for a long time...

"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz


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Old 10-08-2012, 12:11 AM
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Quote:
Originally Posted by lovinthehd View Post

Yeah, that would explain some others that get reported as fine with 4ohm but when I look up specs there aren't any for 4 ohm....so if you did drive this 356 at sustained volume for a long time....would it spontaeously combust ? cool.gif
ps Looked up Box Canyon cuz I couldn't place it...but my brother lived in West Hills for a long time...


How well the amplifier holds up really depends upon a couple of things..
A. How loud is it played?
B. Type of music played?
C. Size of listening room
D. The specs of the connected 4 Ohm loudspeaker such as sensitivity..

Anyway the amplifier should do fine, most of NAD's products are quite reliable..


Box Canyon is 3 miles north of West Hills, just south of Santa Susana Pass Road...
Just below Roy Roger's original place, near the Spahn Ranch...

Just my $0.02... wink.gif
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Old 10-08-2012, 02:51 AM
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If it's any comfort or consolation, look at Emotiva's stereo and mono amps. The 4Ω rating is not 2x, but about 50-60% more. So is my 27.5lb $$ mono. So this is a realistic and educated guess the NAD should be broadly similar.

But my other $$ 45.5lb dual mono integrated amp does 150W 8Ω and 300W 4Ω.smile.gif It is driving 4Ω and runs cool with its metal casing and side heat sink.smile.gif

Moral of the story: if you want doubling the W for 4Ω it's gonna to cost you...

Audiosceptics accept audio trials using 25 people. A recent Oxford study with over 353,000 patient records from 639 separate clinical trials shows for every 1,000 people taking diclofenac or ibuprofen there would be 3 additional heart attacks, 4 more cases of heart failure and 1 death every year.

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