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What would I possibly hear different at 120 watts vs 200 watts?

2Sunny

2Sunny

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So assuming 5 speakers all at 8 ohms and between 87-90 dB sensitivity, I'm debating on whether to upgrade my amp from an OutLaw 5000x to and Emotiva XPA-5, but here's the thing . . . I never listen to anything too loud. I guess then the question is:

At lower listening levels will I notice a difference between amps or would the difference in sound only be noticeable as one approaches a level of sound where distortion sets in?

5 speakers tentatively planned:
Revel Performa F226Be - towers
Ascend Acoustics DUO V2 LCR ribbon - center
Ascend Acoustics Sierra 1 V2 - bookshelf
 
Researching power for speakers online has brought up a second question.

Does anyone know how much power a speaker typically draws when watching a movie and there is a sudden explosion or thunder or other loud burst?
 
most power is actually from the sub. Your speakers (and amp) should be fine for such burst, given the amp is actually competent.
 
I find this an interesting question: If 2 amps (e.g. 120 & 200 W) are producing the same SPL, and given that the task at hand is for both amps well within their capabilities, is there an audible difference? Does the remaining, not used, additional power have any perceivable benefit?
 
Settembrini said:
I find this an interesting question: If 2 amps (e.g. 120 & 200 W) are producing the same SPL, and given that the task at hand is for both amps well within their capabilities, is there an audible difference? Does the remaining, not used, additional power have any perceivable benefit?
Click to expand...
Unused power remains unused and makes no difference -until you need it.
 
kemmler3D said:
Only if there are big peaks the amp can't handle. The difference between 120w and 200w is only 2.2db either way, so pretty hard to notice in that context.
Click to expand...
Wow. I had no idea the difference was so small although I did make a minor mistake in that the Emotiva is rated at 250 watts at 8 ohms with all channels driven, but really it sounds like 120 is plenty for me.
 
I think you are well set as noted above :D.

If you want to complicate your life though, or just curios, there is always another rabbit whole laying around. Sure there are plenty of threads on this forums, but this just came up first on G.

www.audioholics.com

Understanding Ohm's Law, Impedance And Electrical Phase 101

Do you ever wonder what makes a loudspeaker "difficult to drive"? Do you wonder what's so special about an amplifier that is stable into a 4-ohm load? Audioholics looks to answer these questions here.
www.audioholics.com www.audioholics.com
 
As long as the amplifier is operating within its design limits then a Watt should just be a Watt and there should be no affect on sound quality. As long as the amp doesn't clip on dynamic peaks in passages of music then there should be no clipping/distortion at normal listening levels.

There's an open question (for me anyway) about what those peaks look like and how big they get. I've tended to think about them in terms of amplifier 'headroom' and I use a simple calculator to estimate their impact: https://www.crownaudio.com/en/tools/calculators#amp_power_required
e.g.
Listening at 80dbSPL (pretty loud for me) at a 3m distance with 87dB sensitivity speakers ...
(as your speaker impedance drops then you need more power, which is why I start with a level that is too loud for me most of the time)
Headroom of 12dB suggests power requirement is only 28W
if you raise the headroom to 20dB - which seems like a lot, but I've read here a few times is reasonable - then you need 180W to avoid clipping

If those peaks are very transient then you probably won't notice any clipping anyway, especially at higher frequencies, but it's interesting if you are trying to avoid clipping for purist reasons.
Short version ... more power is good for a reason, but might not be of any practical benefit.

I can't answer the 'power draw' question I'm afraid.
 
2Sunny said:
Wow. I had no idea the difference was so small although I did make a minor mistake in that the Emotiva is rated at 250 watts at 8 ohms with all channels driven, but really it sounds like 120 is plenty for me.
Click to expand...
Yep, it's sort of distressing when you first find out that 2x amp power only gives you 3dB more from the speakers. So by the time you hit 100-200w you're already near the end of the road for amp power, unless you want to spend thousands on super-high-end stuff.

3dB is a noticeable change but not a huge one. If you are clipping peaks and it's bothersome the extra 3dB going from 120 to 250 might be audible. But it won't be night-and-day unless you're already pushing the amp to the limit all the time.

If you play with an SPL vs Watts calculator like this one the advantage of sensitive speakers like yours becomes clear... https://mehlau.net/audio/spl/

Power draw tends to be surprisingly low, and corresponds to the RMS of what you're listening to... in most cases the idle power use of the amp will be as much or more than what the speakers are using. So for a 5x120w amp, maybe you will see 30w power draw at zero ouput and 35 at normal listening levels. (just for example.) Peaks won't tend to register on a power meter (too fast) and won't add to the total power bill much either.
 
It’s also worth noting that we don’t always know exactly how loud we’re listening. Without measuring, I wouldn’t be able to pinpoint whether I’m at 80 dB average or 77 dB.

A 3 dB increase is just noticeable but requires double the power. Add in different types of music -some bass-heavy, some highly dynamic, and you can easily see a 20 dB difference between average dBA avg. and peak dBC. This means that to properly reproduce such music, you’d need about 90 times the power for transients compared to the average listening level, for 87 dB sensitivity speakers at 3 m. distance.

The following is a measurement I took using the NIOSH app, which is reasonably accurate with an iPhone, at least enough to illustrate the point.
It’s from a typical pop/EDM track, Flames by David Guetta and Sia. Nothing unusual.


1743440193885.png
 
The topic is explored in more detail in the thread below, beginning around Doodski's comment.

www.audiosciencereview.com

WiiM Amp Pro Streaming Stereo Amplifier Review

I'm not sure why so many people on this forum are so focused on power. I have a 35m² open living space, a 50W amplifier, and just two speakers. I usually listen at around 12% volume, and it's already loud. If you have a family or a partner, when would you even need to go up to 60%? When no one's...
www.audiosciencereview.com www.audiosciencereview.com
 
It's an interesting discussion. Apart from the engineering limitations, there seems to be the overall dynamic range considerations. And not sure how it really works. Thus the question.

If you AVR/AVP can do 108 dB dynamic range, than I would assume that nothing beyond that would be possible as it would simply equalise the peaks beyond that range to fit within the specs? Not really clipping at least what I would think.

But then if the AVR/AVP can do 113db range, that would actually require more resources, assuming reference volume. 113dB would be close to the 115dB limit set by Dolby for the LFE, but than again that would fall in the sub territory that handless its business with its own amps. And people often use the curves where they set the low end +10dB, which is actually in excess of these specs, by far. You can always push the voltage with the AVR/AVP, but the question is how will the other side handle it?
 
@kemmler3D That website really makes it easy to see what's necessary and what's not. Looking at the least sensitive speaker in the list I still come up with 100 dB at 120 watts which is WAY higher than I would ever listen or I think higher even than any transient I'm likely to encounter. I was already pretty sure the idea of upgrading my amp was a bad idea, but after playing with that calculator I have no doubt that the OutLaw 5000x is plenty powerful enough for me :)
 
kemmler3D said:
Yep, it's sort of distressing when you first find out that 2x amp power only gives you 3dB more from the speakers. So by the time you hit 100-200w you're already near the end of the road for amp power, unless you want to spend thousands on super-high-end stuff.
Click to expand...
So... if I understand correctly, and we have 2 amps of the brand X (100w & 200w) with an increase in price of about 50%... then the 100W is the better value, right?
 
Settembrini said:
So... if I understand correctly, and we have 2 amps of the brand X (100w & 200w) with an increase in price of about 50%... then the 100W is the better value, right?
Click to expand...
Well, it depends on what you need from your system and how you value it. If you think +3dB without distortion is worth 50% more money, then the 200w is a better value. :)
 
You may want to use these 2.2dB if you're EQing (wrongly, but I have seen DIRAC doing it so...) filling dips though. Maybe more.
Doesn't matter if you use subs,at normal music the main bulk is at the combined 100Hz-1kHz area (people tend to think tones but spectrum is a additive matter)

Whoever uses a 3 way active can see it with basic tools, power drawn is usually balanced between the above area and the 20Hz-100Hz one (movies can be a little heavier down low though,due to the effects )

I would consider all factors when it comes to power, including gain compensation, losses,etc.
 
I already own the OutLaw so no intention of not using it, BUT . . . am I correct in the simple interpretation of the bench test linked below.

Sony STR-ZA5000 ES A/V Receiver Review Test Bench

Test Bench Two channels driven continuously into 8-ohm loads: 0.1% distortion at 139.3 watts 1% distortion at 175.3 watts Five channels driven continuously into 8-ohm loads: 0.1% distortion at 103.6 watts 1% distortion at 135.1 watts Seven channels driven continuously into 8-ohm loads: 0.1%...
www.soundandvision.com www.soundandvision.com

The Sony STR AZ5000ES can hit 100 watts per channel on 7 channels simultaneously?

Assuming for a moment that's true am I further correct in this scenario (using the SPL website).

Let's say one is listening to a movie at 85 dB 3.5 meters back; the channel draw would look like this:

towers 90 dB sensitivity = 2 watts x 2 = 4w
center 87 dB sensitivity = 4 watts x 1 = 4w
bookshelf 86 dB sensitivity = 5 watts x 2 = 10w

total = 18 watts!

So under normal listening levels the amp is barely using power. Then comes a loud noise pushing to 100 dB

towers 90 dB sensitivity = 62 watts x 2 = 124w
center 87 dB sensitivity = 120 watts x 1 = 120w
bookshelf 86 dB sensitivity = 120 watts x 2 = 240w

total = 484 watts

The amp is still no where near 7 channels at 100w or what I assume was 700 watts plus during the bench test, and this is just momentary. Kinda looks like an amp is 100% unnecessary if all that is correct.
 
As mentioned earlier, the power difference between 120W and 200W is just 2.2dB.
Many speakers have sensitivities of 85dBSPL@1W or better, therefore at loud listening level of 85dBSPL, the amplifiers are likely to be operating in the 0.1W-10W range.
Even if we upgrade the amplifier to 200W and listen at the same levels, the new amp will still be operating in the 0.1W-10W range.
Where did the extra 80W go to? Into spare capacity (headroom).
 
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