Speaker Wattage

[Big Dub Sounds]

Hey Guys,

Easy question that I can't seem to find a straight answer to. Assuming all other factors are equal will a higher watt speaker play louder if the receiver is the same? Basically what is the advantage of a 200w speaker vs 100w? Also is higher ohms or lower ohms better?

 

[lovinthehd]

Speakers aren't defined that way; max speaker power ratings don't mean a whole lot and can be defined differently by different manufacturers. It is often simply the melting point of the speaker and may sound like crap if fed that much. Is it a continuous power rating or a peak power rating?

You need the sensitivity spec to determine relationship of loudness for a given amount of wattage fed the speaker. Try using an spl calculator as a way to approximate (and consider sensitivity specs can be fudged a bit and can be spec'd differently as well from maufacturer to manufacturer).

Lower impedance speakers pose greater loads on the amplifier, so make sure an amplifier is suited to the speakers' impedance rating (and perhaps look beyond the simple nominal impedance rating). Maybe this article can help http://www.audioholics.com/loudspeaker-design/truth-about-matching-amplifier-power

 

[Big Dub Sounds]

Thanks this really helps. It's more continuous power I was looking at. Trying to figure when a manufacturer sells two speakers in a series and the main difference in the more expensive one is higher wattage (as well as a larger speaker), but otherwise the specs are similar.

 

[lovinthehd]

Thanks this really helps. It's more continuous power I was looking at. Trying to figure when a manufacturer sells two speakers in a series and the main difference in the more expensive one is higher wattage (as well as a larger speaker), but otherwise the specs are similar.

Not enough to judge on really. Look at more than max wattage, that really doesn't indicate a whole lot.

 

[Big Dub Sounds]

Oh Yeah I understand , what are the most important specs to look at with speakers?

 

[yepimonfire]

Hey Guys,

Easy question that I can't seem to find a straight answer to. Assuming all other factors are equal will a higher watt speaker play louder if the receiver is the same? Basically what is the advantage of a 200w speaker vs 100w? Also is higher ohms or lower ohms better?

A higher sensitivity speaker will play louder with the same power, a higher wattage speaker will take more power before blowing. Neither 8ohm or 4ohm is better. A 4 ohm speaker will rely more on current rather than voltage for power, all things being equal. A good majority of amps in AVRs will struggle with 4 ohm loads since the burden is shifted off the voltage rails to the (often lacking) power supply, and more current = more heat.

A 100wpc receiver rated at 8 ohms likely has a maximum voltage output of 28v. On an 8 ohm load, around 3.5 amps equates to 100w. Into 5 channels this is a total of 14 amps. At 4 ohms 100w equates to 5 amps, with 5 channels going this is 25 amps. That's a crap load of current, without a sufficiently large power supply and really good cooling, you're likely to run into problems. Lack of current is exactly why a receiver rated 100wpc into 8 ohms 2ch drops to as low as 60-70wpc all channels driven.

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[ski2xblack]

Oh Yeah I understand , what are the most important specs to look at with speakers?

Things that are important include the following (this list is just a start, but I consider these to be of critical importance): flat on axis response; smooth off axis response, i.e. no frequency response aberrations off axis; wide dynamic range; low distortion.

Audioholics has quite a few articles under the research tab on the main page going into this further, and how specific engineering goals are quantified in measurements or assessments of different types. Manufacturers often fudge important specs like sensitivity and impedance, and most provide zero measurements off axis response or disclosure thermal compression limits. You're left pondering their 'nominal impedance' and vague power handling and sensitivity specs. Makes shopping fun, doesn't it? Fortunately, there is enough collective knowledge and experience here to shed some light on this subject.

 

[MR.MAGOO]

A higher sensitivity speaker will play louder with the same power, a higher wattage speaker will take more power before blowing. Neither 8ohm or 4ohm is better. A 4 ohm speaker will rely more on current rather than voltage for power, all things being equal. A good majority of amps in AVRs will struggle with 4 ohm loads since the burden is shifted off the voltage rails to the (often lacking) power supply, and more current = more heat.

A 100wpc receiver rated at 8 ohms likely has a maximum voltage output of 28v. On an 8 ohm load, around 3.5 amps equates to 100w. Into 5 channels this is a total of 14 amps. At 4 ohms 100w equates to 5 amps, with 5 channels going this is 25 amps. That's a crap load of current, without a sufficiently large power supply and really good cooling, you're likely to run into problems. Lack of current is exactly why a receiver rated 100wpc into 8 ohms 2ch drops to as low as 60-70wpc all channels driven.

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So if a manufacturer does not mention the speaker sensitivity on their website or owners manual is that something to be suspicious about?

 

[Bucknekked]

A higher sensitivity speaker will play louder with the same power, a higher wattage speaker will take more power before blowing. Neither 8ohm or 4ohm is better. A 4 ohm speaker will rely more on current rather than voltage for power, all things being equal. A good majority of amps in AVRs will struggle with 4 ohm loads since the burden is shifted off the voltage rails to the (often lacking) power supply, and more current = more heat.

A 100wpc receiver rated at 8 ohms likely has a maximum voltage output of 28v. On an 8 ohm load, around 3.5 amps equates to 100w. Into 5 channels this is a total of 14 amps. At 4 ohms 100w equates to 5 amps, with 5 channels going this is 25 amps. That's a crap load of current, without a sufficiently large power supply and really good cooling, you're likely to run into problems. Lack of current is exactly why a receiver rated 100wpc into 8 ohms 2ch drops to as low as 60-70wpc all channels driven.

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great primer. I saved that answer for future reference. I am moving to new speakers hopefully this week.
I upgraded my AVR because my old ones are 8 ohm and my new ones somewhere between 4 and 6 ohms, with the overall rating at 6ohms. I found your answer a good way to explain the voltage and current tradeoffs.

 

[Bucknekked]

So if a manufacturer does not mention the speaker sensitivity on their website or owners manual is that something to be suspicious about?

Mr.Magoo:
I think its a safe bet that any manufacturer that isn't trumpeting a feature from the ramparts is generally because they don't have much to shout about. If a manufacturer has a great number, like 95db for a Klipsch, they make lots of noise about it.

If a manufacturer makes a speaker that just drags along at 84db or so, it would be more trouble to explain why than to just let it go unnoticed. Speakers that are not particularly sensitive are not bad speakers, nor is a low sensitivity number an indicator of poor design. Not at all. There are lots of high quality speakers that made the tradeoff for low sensitivity.

I am suspicious of everything manufacturers say and particularly what they don't say. I think a little skepticism is a good thing.

 

[MR.MAGOO]

Mr.Magoo:
I think its a safe bet that any manufacturer that isn't trumpeting a feature from the ramparts is generally because they don't have much to shout about. If a manufacturer has a great number, like 83db for a Klipsch, they make lots of noise about it.

If a manufacturer makes a speaker that just drags along at 95db or so, it would be more trouble to explain why than to just let it go unnoticed. Speakers that are not particularly sensitive are not bad speakers, nor is a low sensitivity number an indicator of poor design. Not at all. There are lots of high quality speakers that made the tradeoff for low sensitivity.

I am suspicious of everything manufacturers say and particularly what they don't say. I think a little skepticism is a good thing.

Now I'm confused, how is 83db great and 95db just dragging?

 

[Bucknekked]

Now I'm confused, how is 83db great and 95db just dragging?

I had a mental meltdown and reversed the numbers.
95db would be very sensitive and 84db considered less sensitive.
I just got done writing another post where I had the numbers exactly bass-ackiwards and I took that mindset in to your post. I apologize profusely for a brain dead post.
A mind is a terrible thing to waste.

 

[lovinthehd]

So if a manufacturer does not mention the speaker sensitivity on their website or owners manual is that something to be suspicious about?

I'd wonder why the omission for sure. No (good) reason to hold back, it's just information.

 

[-Jim-]

Hey Guys,

Easy question that I can't seem to find a straight answer to. Assuming all other factors are equal will a higher watt speaker play louder if the receiver is the same? Basically what is the advantage of a 200w speaker vs 100w? Also is higher ohms or lower ohms better?

Question 1 answer: No. Speaker wattage ratings are for the unenlightened purchaser in most cases. Sensitivity, and other data is of far more value in determining the short list of speakers to listen to before purchase.

Question 2 answer: Not a lot if that's the only difference. Sometimes OEMs use this rating simply as a marketing tool as some folks always think a bigger number is better.

Question 3 answer: Not really, but in some cases where an existing amplifier (receiver) can't handle 4 (nominal) ohm loads, it's better to go towards 8 ohm speakers. Also some amplifiers (receivers) will also advise if you want to add a second pair of speakers for another area (or zone), you should go with 8 ohm speakers. So you need to look at what you eventually want to have as a system when deciding on speakers - even if you buy them a pair at a time.

 

[MrBoat]

Sensitivity is perplexing to those of us who have been used to RMS wattage ratings in the past before all of this information became so mainstream on the internet. My current speakers have a sensitivity rating of about 98db and I never thought much of it. Here a few weeks ago, I was trying out an old Harman Kardon 2 channel receiver I have had in my closet for at least 20 (it's probably 40+ years old) years and it is rated for 35 wpc. I pretty much discounted it as a wimp so is why I never really cared to know how well it worked.

When I hooked it up to my new speakers, I was shocked at how loud it was at such low volume levels. Not only that, but the thing actually sounds really good. It's probably an actual, 35 wpc receiver, and these speakers really only need a couple of watts to play really loud. At any rate, it has changed how I look at older equipment and the wattage rating of speakers and older amps. When you look at things like old tube amps that only put out a few watts, you may get an idea how these folks were getting by with such little power.

 

[lovinthehd]

Sensitivity is perplexing to those of us who have been used to RMS wattage ratings in the past before all of this information became so mainstream on the internet. My current speakers have a sensitivity rating of about 98db and I never thought much of it. Here a few weeks ago, I was trying out an old Harman Kardon 2 channel receiver I have had in my closet for at least 20 (it's probably 40+ years old) years and it is rated for 35 wpc. I pretty much discounted it as a wimp so is why I never really cared to know how well it worked.

When I hooked it up to my new speakers, I was shocked at how loud it was at such low volume levels. Not only that, but the thing actually sounds really good. It's probably an actual, 35 wpc receiver, and these speakers really only need a couple of watts to play really loud. At any rate, it has changed how I look at older equipment and the wattage rating of speakers and older amps. When you look at things like old tube amps that only put out a few watts, you may get an idea how these folks were getting by with such little power.

Just part of the basic electrical properties in play rather than idiot marketing guys' way of selling stuff....

 

[Big Dub Sounds]

thanks guys, lot of great info so far in this thread. Like most industries I've found there are two sides to the audio business, the marketing side and the science side. It's tough to get past the marketing fluff and get the real information that will translate to quality sound.

 

[yepimonfire]

Sound quality can be objectively measured. Multiple points of data can be used to determine a speaker's performance.

Sensitivity (1w/1m or 2.83v/1m), while sometimes not 100% accurate, can be used to determine how loud a speaker can play with a set amount of power, it also can be assumed that a speaker with a higher sensitivity rating will play louder with less distortion (as is the case with Klipsch speakers). SPL is logarithmic, each increase of 3dB requires double the power. A 3dB increase is perceived as only slightly louder, while an increase of 10dB is perceived as twice as loud. For every doubling of the distance from a loudspeaker, you lose 6dB. For example, if a speaker is rated at 85dB at 1m, and you're sitting 3m away, you're now only getting 76dB at 1w. To achieve an SPL of 85dB at the listening position, you'll now need about 9w. If you're watching a movie at -15dB (an average home volume level for movies), you'll need to accommodate peaks of 95dB,Lwhich means you now need 75w.

A speakers power rating simply tells you how much power a speaker can handle before it reaches thermal or mechanical limits. There are three numbers that are important. RMS. This is the constant amount of power a speaker can handle. An 80w RMS speaker can handle 80w for an infinite amount of time with no damage. Max or program. Most music and sounds have peak power levels, for example, a kick drums attack has a maximum level, and a minimum level, the "average" between these two is RMS, and the max or program is the attack portion. Peak power refers to the absolute maximum a speaker can handle for a short amount of time. Peaks are things like an explosion in a movie.

If any of these values are known, you can figure out the other two. The max rating is 2x the RMS rating, and the peak is 4x the RMS rating, so a speaker that can handle 100w RMS can endure brief peaks of 400w without blowing. Keep in mind just because it can handle a specific amount of power doesn't mean it will play undistorted at that level. A small bookshelf speaker rated at 85dB might be able to play at 97dB, but it will likely not sound clear And dynamic.

For the actual sound quality of a speaker, one can look at a frequency response graph, distortion figures, and dispersion characteristics. While its not a substitute for hearing it yourself, it can give you an idea of how accurate it sounds.



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[lovinthehd]

Still, the actual subjective speaker sound quality is not always resolved by specific measurements, altho it can help.

 

[lovinthehd]

And the statement sound quality can be measured is inherently a problem. I wouldn't even agree with most of your subjective speaker descriptions. Plus you leave the stupid tapatalk ad which further denigrates your opinions