200 vs 400 watts per channel

[TheEAR]

Acoustical treatment,now we have the most important component,speakers will only sound as good if the room is "neutral" so to speak.And most room are far from this ideal.

And Klipsch users should keep in mind,a complete 5 channel set of larger Klipsch speakers does not even need 200W on peaks,for all channels.As long as you have a quality amp.The extra wattage is gravy to brag about.

[Cal Blacksmith]

AMEN EAR!

To be honest, with our Fort'e mains, Quartet rears and Academy center, even the LOUDEST explosions only draw about 4 YES FOUR watts from the amp powering our main speakers running in "large" configuration!

[JetSnake]

Buy the smaller amp and plug into a 220v outlet. If it holds together, how much head room will that give ya? Just a twisted look at things.

[Fish]

I will admit I didn't read the whole thread but I read enough to see a ? hooking a 400 watt amp to a Denon avr.That would be like putting hubcaps on a wheelbarrow(been there,done that).I'd much rather have a good prepro and a good100 watt per ch amp.

[jacksonbart]

Denon's claimed 120W per channel,is true if ONE channel is driven.The Sunfire power amp,even the least capable one will leave any Denon receiver in the dust.

The point about the plug was for the response above, with the worthless test of all channels driven. I agree, cheaper amp sections of receivers suffer with lacking power supplies, but again better receivers or multi channel amps limiting factor for delivering the true all channels driven to peak at the same time (worthless in mucic and HT) is the curcuit breaker, unless like Indy did was to upgrade to dedicated service. Seperate Amp only help if not attached to the same breaker. Not disagreeing that amps will sound different or the rest.

[Guest " "]

Buy the smaller amp and plug into a 220v outlet. It it holds together, how much head room will that give ya? Just a twisted look at things.

Some amps have dual primary windings and can be converted from 110 to 220. The same cord is used since actual current is cut in half as a result of doubling the voltage.

[getech]

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---

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[oldtimer]

I want the pre-pro and amps (architects choice 17" wide) so bad! Too bad I bought a car instead. Still, there's always next year, plus the car really is fun too. Like OB says, autos and sound are such enjoyable vices.

[Spkrdctr]

Here's my inexperienced take on the issue (based on what we're doing in class right now):

Just because RMS is an "average" doesn't mean that it's an average over a long period of time.

Who, you are correct. That is why it can easily spike much higher for very short periods.

I was also under the impression that electrical codes prohibit any device from pulling more than its rated power out of the wall. An amplifier is only a voltage regulating device and the max voltage is limited by the power supply. The maximum power transfer will occur with a single known load which will also determine the maximum current draw.

EGADS!! You have got it. That is why I "usually" don't worry too much about the "high current" marketing issue with high quallity gear. It will draw enough current to short itself out based on the load. Of course, that is an extreme case. Anyway, I nominate you for high office on these boards. Good work.

So when an amplifier delivers more power than it draws, the only way this can occur is if energy is somehow stored in the amplifier. The typical solution is a bank of capacitors, which are great for single short peaks.

Thses are usually set to recharge quite quickly, but you could still out run the caps if you want to by turning it up too much, causing a heavy demand and then your relying on the power supply itself.

But if the second transient comes along before the caps recharge, then you're in a situation where there isn't enough current available and it clips the transient. I have no doubt the Sunfire engineers have mastered the art of this balancing act, but the fact remains that they're not breaking the laws of physics. The "400W" from these amplifiers is not going to sound the same as an amplifier actually capable of delevering a consistent 400W.

400 watts constant power is enormous for a home theater. Yikes! I'd want a speaker sensitivity of 85 to even start that experiment, or stand back a bit......[]

Headroom is nice, but it's even better when it's linear []

It will be linear if you don't have a home theater source drawing 400 watts all at the same time.....Also, don't forget the spikes, they can be on the order of quadruple what you would have RMS. Again, think electric motor on your 20 amp circuit breaker. (Refridgerator)

All that said, I'm still in the camp that thinks it's a waste to go insane on the amplification when the speakers and room are responsible for levels of distortion that are on the order of several magnitudes larger.

I agree. If your realistically going to run your amp at the 5 watt level or lower as most people with Klipsch speakers do, then you don't really need insane power. I mean operating at .75 of one watt on a 100 watt channel gives you LOTS of headroom.

For example, speaker A has a 95db sensitivity and you listen at 85db to 90db on your home theater peaks, then you have lots of headroom.

I vote for the smaller amp and use the savings towards aesthetically acceptable acoustical treatment.

Plus, you have money left over to make the car payment!

[skonopa]

And Klipsch users should keep in mind,a complete 5 channel set of larger Klipsch speakers does not even need 200W on peaks,for all channels.As long as you have a quality amp.The extra wattage is gravy to brag about.

I also have to "amen" this.

I have 200 watts per channel on my setup, and it gets plenty loud enough for me. If I turned it up as loud as it'll go, I guarentee that you will not want to be in the house with it, at least without ear plugs! Hell, even just out in the front yard, it was insanely loud! And on top of that, there was no distortion that I could detect!

I'll have to agree with many others - yes, 400 watts would be pretty cool, but to be honost, I think the 200 watt one will be much better choice. Now, if the 400 watt one is only a marginal increase in price, then I'd say go for it, but if it is significant (I'd say, at least 25% above that of the 200 watt version), then save the money and go with the 200 watt unit.

[oldbuckster]

Let me ask this question again, I never seem to get an answer..........Isn't it better to have too much wattage, as opposed to too little wattage? Doesn't too little power cause many more problems for speakers and power sources? I never get a real solid answer to that question..........Is there an answer??????

[Coytee]

Let me ask this question again, I never seem to get an answer..........Isn't it better to have too much wattage, as opposed to too little wattage? Doesn't too little power cause many more problems for speakers and power sources? I never get a real solid answer to that question..........Is there an answer??????

My basic opinion is you are right, it's better to have too much instead of too little. However, it can be taken to extremes in both cases?

If you have a pair of Khorns plumbed into a 200 watt amp, are you better off if those same speakers were plumbed into a 500 watt amp?

How about a 1,000 watter? []

Somewhere there is the idea of diminishing returns. That is probably different for different people. (for example, those who swear only by SET amps? [A] )

[JetSnake]

Oldbuckster, even though I don't have a lot of knowledge on this subject, I like to think I have a knowledgeable opinion. When comparing 200 watts vs. 400 watts of sunfire power, I don't think it's a matter of too little vs. too much, but more like much vs. too much. The 200 watt sunfire is nothing to lift your nose at. I'd wonder if he'd notice a difference if he did buy the 200 watt amp and you snuck in his house a month later to swapped it out with the 400 watt.

Other wise to your question, IMO too much is better then too little. In the sunfire case, you don't have too little.

[Guest " "]

Newer amp have tightly wound power trasformers that can achieve 96 % efficiency and still be withing 3% of their rated voltage at max load. Add to that the 12,000uf to 100,000uf' of computer grade capacitance in the power supply and you have a weak case for needing large amps that deliver 4 times the power that your speakers can handle.

In days gone by, the barebone power supplies set the stage for better sounding 5 watts from a 200 watt amp than 5 watts from a 50 watt amp.

[merkin]

Jet snake, Do you need my address so you can sneak in and hook up a 400 watt amp? I'd even leave the back door unlocked.

I get your point, with efficient speakers I doubt that I need 400 watts for my set up. That was the point of my question to begin with.

As far as those hubcaps on my wheel barrow. I'll put the hubcaps on for awhile, then I plan on upgrading to a nice pre/pro later. I don't want to throw out a couple more grand right now for a TGP5. I thought it looked good since it has HDMI over the TG4.

[TheEAR]

Oldbuckster, even though I don't have a lot of knowledge on this subject, I like to think I have a knowledgeable opinion. When comparing 200 watts vs. 400 watts of sunfire power, I don't think it's a matter of too little vs. too much, but more like much vs. too much. The 200 watt sunfire is nothing to lift your nose at. I'd wonder if he'd notice a difference if he did buy the 200 watt amp and you snuck in his house a month later to swapped it out with the 400 watt.

Other wise to your question, IMO too much is better then too little. In the sunfire case, you don't have too little.

Very corect

In the end its MUCH VS TOO MUCH,any Sunfire amp has all the power most Klipsch can handle.And more

[mas]

Perhaps you might find this of interest. http://proav.pubdyn.com/2006July/July2006SoundInsight.htm

BTW...SpkrDktr & Doc...nice post(s) []

Sound Insight: The Price Of 3 dB

At some point, a sound system simply can't go a little louder.

A 3 DB level increase is a modest one. Subjectively, one might describe it as being a tweak to the loudness of a system. Most infrared remote controls for home entertainment systems are about 1.5 dB per step, and most people who go to the trouble to pick one up and point it will change the level by at least two steps. Quit reading and go try it now....

At low levels
At low playback levels, a 3 dB change can be made without regard for its effect on the audio systems components. The loudspeaker is likely operating well below its thermal limits, so any increase in heat is insignificant. Also, the amplifier is likely operating far below its clipping point, so the loudness can be increased without undue concern regarding distortion.

The logical way to increase the level of a sound system is to start low and slowly advance the level control until the desired level is attained. Most experienced sound people do this by instinct, and they know when to stop.

Because level increases come so easily initially, its easy to forget that a 3 dB level increase exacts an increasingly greater toll in terms of system headroom and loudspeaker heat dissipation.

Efficiency and heat
Loudspeakers are notoriously inefficient. More than 95 percent of the applied power is wasted as heat, which increases the operating temperature of the loudspeaker, rather than converted into sound. If you turn it up 3 dB, it will get a little louder and run hotter.

The loudness increase is logarithmic twice the applied power always produces the same 3 dB loudness increase. The temperature increase is linear each additional watt has the same heating effect. So, if you double the power from 1 W to 2 W, and then from 2 W to 4 W, the loudness will change by 3 dB. But, there will be a larger temperature increase from the second power change, even though it was proportionally the same as the first one. As level is increased in equal loudness increments, the temperature increments get progressively larger with each increase.

The price per watt
Lets say that youre amplifier shopping, and paying one dollar per watt for amplifier power. Loudspeaker sensitivity ratings are usually referenced to 1 watt (actually 2.83 Vrms, but that's s a subject for another column). Lets start there and go up. The power must be doubled to 2 watts for a 3 dB level increase. Four watts gives another 3 dB, and 8 watts yet another. The level increases are relatively inexpensive, and it appears that the sky is the limit regarding the potential loudness of the system. But if you look at the trend, youll see that youll soon run out of money. Every 3 dB increase is twice the cost of the previous. Eventually you wont be able to afford another 3 dB!

If 3 dB is just noticeable, 6 dB can be considered the smallest loudness upgrade worth pursuing. A 6 dB increase represents twice the voltage across the loudspeaker, which quadruples the power that must be dissipated as heat.

Here are some real-world examples of the expected cost of a 6 dB upgrade for different types of sound systems. In each case, Im assuming that only the amplifiers are being upgraded, and that the existing loudspeaker system will be used.
Paging system in a small office: 30 W amplifier to 120 W amplifier about $100
Medium-sized portable PA system: 100 W amplifier to 400 W amplifier about $300
Typical playback system for weekend rock band: 1,000 W to 4 kW about $3,000
Large house of worship system: 20 kW to 80 kW about $60,000
Touring system: 50 kW to 200 kW about $150,000 (and three more trucks)

Note that in each example the same loudness increase (6 dB) was achieved, but at a vastly different cost. Now consider the owner of the medium-sized portable PA system that runs sound at the large house of worship. The relatively low-cost upgrade to the smaller system translates into a major investment in the large one. Its all about proportional change. What you need depends on what you start with. This is why experienced audio people use the decibel system to rate and select audio components the logarithmic relationships are built-in.

Destined for failure
A loudspeaker will eventually succumb to that next 3 dB. It doesnt sound like much, and it came so easy at lower levels. But eventually heat takes its toll and failure occurs. When a loudspeaker is power tested, once its response changes by a few dB due to heat, its very close to its thermal limits. You cant expect another 3 dB. Level is very deceptive. You many only want a little more, but at some point a slight increase produces distortion or component failure due to the logarithmic increase in power.

We hear about the straw that broke the camels back. But in this case, were doubling the number of straws each time we add to the camels load. If hes showing signs of fatigue, it isnt advisable to keep piling it on. Its better to add a second camel.

The moral of the story? Dont load your camel logarithmically! Yet thats exactly what happens each time you turn up a loudspeaker by 3 dB.

Power vs. voltage
The truth is that amplifiers seldom run out of power. Theyre rated using sine waves a signal that has a much higher RMS voltage (and therefore generates much more power) than typical audio program material. Instead, they run out of voltage swing. When normal program material lights the clip indicator on an amplifier, its likely at one-tenth or less of its rated sine wave power output. Further level increases produce more severe clipping, and the amplifier power output continues to rise, escalating toward the sine wave power production reflected by its power rating. An inexperienced system operator will often turn the sound level up so much that the amplifier clips. They want it louder yet, so they continue upward with the volume control. Because the amplifier is out of headroom, each 3 dB increase clips the signal more severely. The power output of this amplifier is going up, even though its heavily distorted.

It takes an amplifier rated at about 100 watts to produce 10 clean watts into a loudspeaker. Likewise, it takes an amplifier rated at about 1,000 watts to produce 100 clean watts into a loudspeaker. Peak limiters can allow an amplifier to play louder by reducing the program peaks and allowing the amplifier to generate a higher RMS voltage across the loudspeaker. While the fidelity may suffer, the sound definitely gets louder, and the voice coils definitely get hotter.

A systems ability to go 3 dB louder diminishes with increased level. Eventually the next 3 dB will max out a system component, causing amplifier clipping, thermal failure of the loudspeaker, or both.

The bottom line? At some point, a sound system simply cant go a little louder. A perfectly reasonable request for a slight loudness increase at low playback levels can be an absurd request at high playback levels. If you ignore the warning indicators, something will fail. A sound system thats operating at half power is nearly all the way up.

Pat Brown

The Price of 3dB.pdf

[Guest " "]

The author of The Price Of 3 dB is welcome to come over to my house and hear what 1 watt of power sounds like. And if he wants to go deaf, I'll show him what he needs to do to hear 16 watts, after I step outside.

[colterphoto1]

The EAR: "And Klipsch users should keep in mind,a complete 5 channel set of

larger Klipsch speakers does not even need 200W on peaks,for all

channels.As long as you have a quality amp.The extra wattage is gravy

to brag about."

I'm using LS and CW with my Yamaha 2400 receiver, rated at 110 wpc, probably more like 60-75 wpc. But it's plenty loud for movies at -20 db, so still plenty of headroom.

Of course the THX subs really help bring it to life, but I'm more than happy with my setup as is.

Michael

[jamesV]

For the spl/db/watts drill...yes.

I posted a Klipsch provided graph a few weeks ago that also intorduced "distortion" and "driver failure" as 2 other factors.

Speakerfritz, can you get me a link to that or repost it. I did a search and couldn't find it. Thanks.