How much power do your speakers need? Is low power or high power amp more dangerous?

[AcuDefTechGuy]

74% of AVRs sold today have amplifiers rated @ 85 watts or less

88% of HT systems sold today are with smaller satellite/subwoofer loudspeakers, typically requires more output power to achieve a target SPL vs. full-range loudspeaker

>78% of the AVRs sold today are by less knowledgible staff either through the internet and/or big-box retailer

Bottom line, the higher end market segment are for the most part simply more knowledgible....

Plus typically their loudspeakers tend to be more expensive and designed to handle more abuse.

I always thought people who blow their speakers are usually in the higher-end crowd. For example, I’ve heard people blowing diamond tweeters in their B&W 800Ds or beryllium tweeters in their Revel Salons.

Also, it seems the mass-market low-end less knowledgeable crowd needs the most help. It would make a lot more sense to sell dummy-proof systems for these people. Otherwise there would be a lot of complaints from millions of these people who own $300 HTIB systems regarding their blown speakers.

 

[highfigh]

I don't know where this turned into I'm blasting engineers. Never said that I just stated the things about accuracy that I disliked when I first got into this that I had to learn the hard way to work around.

As for the marketing I work in psych nursing. And that's where my naivety and eyes were opened up. Big Pharma was sued an astronomical sum for fudging the numbers and results some they even hid of serious side effects of Zyprexa. It's not just audio that pulls this practice. It's everywhere. It's in human nature to fudge or pitch something to get them the success they want out of it. If they will do it with medicines that can have a permanent impact on your life. They'll Damn well do it with audio

I've learned to accept that about life. But I don't have to like it.

I'm kind off for the ignorant consumer on this one. Because I've been one. Math and science were a struggle on me. But poetry and philosophy I could ace without even trying. Probably why I can talk a 280 lb psychotic to calm down in the quiet room without him getting physical and putting 4 dudes in the hospital and Joe Blow over there can design a speaker that can sing to the angels. Something I never could do

Learning on these sites and doing research can be a pain in the a@$! Because of the sometimes condescending elitist smug attitude of the ones with the knowledge that we are humbling ourselves to learn it from. Don't fudge specs then tell me I should have been paying more attention in school. I was paying attention and so were a lot of other people. But either our minds aren't gifted in that way or you got a soccer mom with 3 kids who really wants to get something that sounds nice but doesn't have the time to be up on audioholics all night long.

Could these companies A either take there honest money and provide them with better information. Or B could some of the people with the knowledge be a little compassionate and dumb it down for the person rather then rubbing it in there face what they should know when they finally do reach out on these sites? So many members on these forums are so awesome and helpful. But you always gotta get the ones that try to think they can talk to you like your 5 years old.

Its that narrow minded attitude that hurts people from wanting to learn more about this awesome hobby in the long run. Who wants to learn when they gotta get there face rubbed in it?

Once again it's just life I gotta accept it but don't expect me to like it. Thats how I feel about it any way

I think this paragraph made me think you blame engineers because marketing departments only take the specs and add their BS to the mix but only after they have taken the time to misunderstand them but you need to read it again to see that it was a bit of a rant.

"I also hate that +- 3db. Really? Just spit it out fellas. Where can this baby really play too and where does it fall off at. If I like the speaker I'm gonna buy it anyways. I really don't care about the useless extension down to 38hz I can t hear that I'll be driving a sub for anyways. I get that you pretty much can measure where it falls off at by the +- measurement."

Some people will have the snob attitude, but some are here to offer advice and info. The problem is that the info does become overly technical, but only because it's an attempt to describe what's happening with equipment that produces emotional responses from using it when the experience was good, or even better than that.

Personally, I don't like the flowery words used to describe what is heard. There's a saying that goes something like this- "Talking about music is like dancing about architecture", meaning that either is a useless way to describe or explain it. I don't want to meet the person who said something about 'chocolatey midrange'.

I didn't mean what I posted in a negative way to users, but I have dealt with marketing hype in audio for over 40 years, so maybe it was like flipping a switch when I read your comments. Yes, reading about the technical aspects is a PITA, can be boring and a lot of it flies over the heads of people who have dealt with it for decades because there's nothing simple about it. I get some of my best sleep during manufacturer webinars.

After dealing with this stuff for over 40 years, I understand the rant about specs and you're not alone- most of us in the AV industry hate the way specs are written, too. Reps like them, but most don't understand them and their job is to move boxes. That's a big problem for those of us who DO need correct info and the reps/sales people can't give them to us.

 

[highfigh]

I always thought people who blow their speakers are usually in the higher-end crowd. For example, I’ve heard people blowing diamond tweeters in their B&W 800Ds or beryllium tweeters in their Revel Salons.

Also, it seems the mass-market low-end less knowledgeable crowd needs the most help. It would make a lot more sense to sell dummy-proof systems for these people. Otherwise there would be a lot of complaints from millions of these people who own $300 HTIB systems regarding their blown speakers.

It's not so much people in the higher-end crowd, I think it's people who bought higher-end equipment and don't know how to operate it without blowing their tweeters. That requires knowledge of the technical details and how they relate to what's happening.

You want dummy-proof to prevent blown speakers? Look at Sonos. It can't be turned up high enough to cause massive distortion. The one thing that would do the same with receivers/preamps and AVRs is limiting the output level and AVRs have that ability, if anyone (besides a small number of people) would care to use it. Make a 300W amplifier but limit the output to 200W and you probably won't blow speakers that are made to handle high power. I limit AVRs to -10dB because -0dB is usually louder than most will need and it WILL damage someone's hearing.

 

[AcuDefTechGuy]

It's not so much people in the higher-end crowd, I think it's people who bought higher-end equipment and don't know how to operate it without blowing their tweeters. That requires knowledge of the technical details and how they relate to what's happening.

You want dummy-proof to prevent blown speakers? Look at Sonos. It can't be turned up high enough to cause massive distortion. The one thing that would do the same with receivers/preamps and AVRs is limiting the output level and AVRs have that ability, if anyone (besides a small number of people) would care to use it. Make a 300W amplifier but limit the output to 200W and you probably won't blow speakers that are made to handle high power. I limit AVRs to -10dB because -0dB is usually louder than most will need and it WILL damage someone's hearing.

I also limit all my AVRs and Pre-pros to -10dB.

And I'm sure it has been said many times before - the people with the proclivity to blow speakers tend to blow all speakers great and small, cheap and expensive.

The question is, do people with the proclivity to blow speakers tend use external amps or just AVR?

What is the incidence of speaker damage in the population that only use HTIBs and AVRs under $400?

Most of my friends, family, relatives, acquaintances only use cheap AVRs and HITBs. And I have never heard anyone of them complain about damaging speakers.

The only people I've heard complain about damaging speakers are the ones who use external amps.

Do you guys have the opposite observation/impression?

Have you guys heard more cases of speaker damages among people who use only AVRs and HTIBs compared to people who use external amps?

 

[Out-Of-Phase]

Back in my audiophile (audiophool) days, I owned separates with B&W 801 Matrix Series 2 speakers.

I never, ever blew anything up in those speakers. They were the Rock of Gibraltar. I remember turned it up loud, real loud and I must admit the sound was clean, clear and precise with no audible distortion at all (however, inaudible distortion might be another story).

 

[AcuDefTechGuy]

Back in my audiophile (audiophool) days, I owned separates with B&W 801 Matrix Series 2 speakers.

I never, ever blew anything up in those speakers. They were the Rock of Gibraltar. I remember turned it up loud, real loud and I must admit the sound was clean, clear and precise with no audible distortion at all (however, inaudible distortion might be another story).

I think most of us here would never blow any speakers with any amps or AVRs.

What about people who are not like us?

 

[PENG]

I also limit all my AVRs and Pre-pros to -10dB.

And I'm sure it has been said many times before - the people with the proclivity to blow speakers tend to blow all speakers great and small, cheap and expensive.

The question is, do people with the proclivity to blow speakers tend use external amps or just AVR?

What is the incidence of speaker damage in the population that only use HTIBs and AVRs under $400?

Most of my friends, family, relatives, acquaintances only use cheap AVRs and HITBs. And I have never heard anyone of them complain about damaging speakers.

The only people I've heard complain about damaging speakers are the ones who use external amps.

Do you guys have the opposite observation/impression?

Have you guys heard more cases of speaker damages among people who use only AVRs and HTIBs compared to people who use external amps?

I know you owned a pair of B&W 802D2 before and never blew them, but I was told by one dealer who claimed he was blowing the diamond tweeters when using Bryston 14B so he had to switch to Classe (iirc), yet B&W was promoting the much lower end and less powerful Rotel amps at the time.

 

[AcuDefTechGuy]

I know you owned a pair of B&W 802D2 before and never blew them, but I was told by one dealer who claimed he was blowing the diamond tweeters when using Bryston 14B so he had to switch to Classe (iirc),yet B&W was promoting the much lower end and less powerful Rotel amps at the time.

Interesting about B&W dealer recommending lower-power amp.

Yeah, my B&W Dealer also said that he has had customers needing to replace their diamond tweeters.

He told me that nonchalantly as if it were no big deal.

I think the reason was because when they delivered my first pair of 802D2, they broke one of the diamond tweeters.

The dealer said it's no big deal to replace the tweeter. But I would have none of that. I demanded new speakers with new serial numbers just to be sure!

Why spend so much money on some drivers that are significantly more brittle/fragile (diamond, beryllium)? Sure, they always claim the more expensive drivers "sound much better", although they could never prove it with speaker measurements.

Why not use driver materials that are the most durable (titanium, carbon fiber) and have the best power handling, sound great, and measure great (anechoic, pseudo-anechoic)?

That's a whole another subject - driver materials - another can of worms. Someone else can open a new thread on that.

 

[Steve81]

I'm a little late to the party, but I've got a some input to toss in...

I've seen two theories (that aren't mutually exclusive) on why an under powered amp is likely to damage a speaker. The first has already been brought up, i.e THD from clipping shifts more content towards the tweeter.

The second has to do with the compression associated with clipping. Suppose someone was pushing an amplifier to the point where it was clipping/compressing the peaks. Depending on the duration of the clipping and the program material being used, the user may not really notice anything amiss. However, that compression could be the difference between "it's loud enough" and "crank it up another 3dB", doubling the average power delivery from the amp to the speaker, and leading to more distortion to the tweeter.

 

[mtrycrafts]

Of course Hyper Physics was right! The only caveat is that what you quoted has to do with clipped wave that are symmetrical. In practice, I would assume in severe case of clipping, the waveform would likely be asymmetrical, at least slightly, so I don't see the need to exclude even order harmonics though their magnitude would be much lower perhaps to the point of being insignificant. I have recently started the process of gradually sorting and sending my university text books and notes to garbage, now I feel like keeping anything that has to do with audio and Fourier.

OK. Should have read further into Hyper Phys

Yes, it contains even harmonics but at a much lesser amount when signal is not symmetrical.

ps. Just noticed the 10th and 12th harmonic is missing. Wonder why.

 

[PENG]

OK. Should have read further into Hyper Phys
View attachment 26595

Yes, it contains even harmonics but at a much lesser amount when signal is not symmetrical.

Wow, thank you for the follow up. It has been so many years since I study Fourier, as part of the communication course so memory is fading.. You've just brought up another key point that is worth noting. In the Hyper Physics example, you can see that by the time it gets to the 17th harmonic, the magnitude is already disappearing small. 17th harmonic of a 1 kHz fundamental is 17,000 Hz, that would certainly be passed onto the tweeter, but again, the magnitude of such high order harmonics resulted from clipping may not be as damaging as people made them out to be.., and obviously this particular point is contents dependent.

Once again, most of the time the appropriate answer to the question raised by ADTG, really should be "it depends.." The dependent variables should include, but not limited to: media contents being played when it clipped, severity of the clipping, the specific speaker (tweeter rating, crossover design/specs) and the specific amplifier (power rating, distortion profile, with/without soft clip by design, sharp rise in distortion after knee point, types and characteristics of the amp's protective features etc.) being abused by the idiot and how much of an idiot the idiot is?

 

[ski2xblack]

The second has to do with the compression associated with clipping. Suppose someone was pushing an amplifier to the point where it was clipping/compressing the peaks.

Check THIS out, particularly section 2 on amplifier clipping. It seems to directly address your question. It's also relevant for @PENG's and @mtrycrafts discussion of the relative power of harmonics.

 

[AcuDefTechGuy]

...In the Hyper Physics example...by the time it gets to the 17th harmonic, the magnitude is already disappearing small. 17th harmonic of a 1 kHz fundamental is 17,000 Hz, that would certainly be passed onto the tweeter, but again, the magnitude of such high order harmonics resulted from clipping may not be as damaging as people made them out to be... It depends........

I think the only way to answer the question is by going through some cases. So let’s present some cases that newbies may face.

Case #1. Newbie #1 bought a pair of speakers before consulting with AH members. He said his tower speakers are rated for 50-300 Watts. He sits 4 meters from this Speakers. His average volume is about 80dB, peak is 100dB. His speakers are 8 ohms nominal, min impedance is 4 ohms around 60-100 Hz. Sensitivity is 85dB/2.83v/m. He also has a pair of 12” Velodyne Subwoofers with 500W power.

Newbie #1 asks How powerful should his amp be? 100W? 200W? 300W? 500W?

 

[Danzilla31]

I think the only way to answer the question is by going through some cases. So let’s present some cases that newbies may face.

Case #1. Newbie #1 bought a pair of speakers before consulting with AH members. He said his tower speakers are rated for 50-300 Watts. He sits 4 meters from this Speakers. His average volume is about 80dB, peak is 100dB. His speakers are 8 ohms nominal, min impedance is 4 ohms around 60-100 Hz. Sensitivity is 90dB/2.83v/m. He also has a pair of 12” Velodyne Subwoofers with 500W power.

Newbie #1 asks How powerful should his amp be? 100W? 200W? 300W? 500W?

Good idea I like this way of approaching it I'm still learning so I'm looking forward to hearing input from more experienced members how to approach this scenario

 

[ski2xblack]

I think the only way to answer the question is by going through some cases. So let’s present some cases that newbies may face.

Case #1. Newbie #1 bought a pair of speakers before consulting with AH members. He said his tower speakers are rated for 50-300 Watts. He sits 4 meters from this Speakers. His average volume is about 80dB, peak is 100dB. His speakers are 8 ohms nominal, min impedance is 4 ohms around 60-100 Hz. Sensitivity is 85dB/2.83v/m. He also has a pair of 12” Velodyne Subwoofers with 500W power.

Newbie #1 asks How powerful should his amp be? 100W? 200W? 300W? 500W?

Given the speaker sensitivity and listening distance, the newb can use one of those handy peak spl/power calculators, and choose amp power accordingly. If the power suggested by the calculations seems unreasonably high for the safety of the speakers, they should consider more sensitive speakers.

 

[PENG]

Check THIS out, particularly section 2 on amplifier clipping. It seems to directly address your question. It's also relevant for @PENG's and @mtrycrafts discussion of the relative power of harmonics.

Thanks, that's a long one to read but it looks good.

 

[highfigh]

I also limit all my AVRs and Pre-pros to -10dB.

And I'm sure it has been said many times before - the people with the proclivity to blow speakers tend to blow all speakers great and small, cheap and expensive.

The question is, do people with the proclivity to blow speakers tend use external amps or just AVR?

What is the incidence of speaker damage in the population that only use HTIBs and AVRs under $400?

Most of my friends, family, relatives, acquaintances only use cheap AVRs and HITBs. And I have never heard anyone of them complain about damaging speakers.

The only people I've heard complain about damaging speakers are the ones who use external amps.

Do you guys have the opposite observation/impression?

Have you guys heard more cases of speaker damages among people who use only AVRs and HTIBs compared to people who use external amps?

I have seen all kinds of people and equipment that damaged speakers. WRT people, I referred to it as 'Spastic Wrist Syndrome'- as soon as their hand got close to a rotary volume control, their wrist started twitching as if they were turning up the volume. They just can't seem to leave the control below maximum, so they kill their speakers. Used to see it with small, medium and high-powered receivers, integrated amps and, although less frequently, separates. HTiB is a bit different- they either don't care about this very much or just use it for background level.

I went to see Rush at an outdoor venue a few years ago and as I waited in the line for a couple of beers, someone behind me asked "Are you Jim, from (the name of the store where I had worked)?". I said I was and he told me his name, but that didn't jog my memory. He then said he used to go there with his friends and he named some of them who were familiar to me. Still wasn't sure and then he said "I blew up a pair of Jamo J-101 in a way you said you had never seen" and I immediately said "Oh, I remember you!". He just hung his head. He had a Pioneer SX-780 driving the speakers and one day, he came in with the speakers, saying they didn't sound right, so I connected them and heard nothing from the mids and tweeters. I told him that, unfortunately, the warranty probably wouldn't be honored because manufacturers usually considered that to fall under 'abuse'. I had asked if he heard distortion and he said he hadn't (I don't know how this wouldn't have sounded like total crap), but as I filled out the service ticket, I told him to bring the receiver in so we could see if that had a problem. His dad came in and started to try to tear me a new one, almost shouting "My kid doesn't crank his stereo full blast!". I asked "Are you at home all day, every day?" and he calmed down, saying "Can you call when they're done?".

The Jamo J-101 has polyswitches on the mids & tweets, a red LED that indicates overload, well-designed crossovers and had Phillips drivers, which were pretty durable. I still have a pair and use them. I have also cranked the snot out of them, sold a lot of them to friends who also cranked the snot out of them and none of us had problems. I used them with a 30W/channel integrated, but NEVER went WOT before replacing that with an integrated amp that was rated at 100W/channel, but tested at 176/channel, both channels driven, at rated distortion and full bandwidth.

We covered the warranty- Jamo was unlikely to say No to us, since we were the 2nd dealer in the US to sell their products and we sold a ton.

We also used to see a regular 'parade' of kids who would come in on Mondays, carrying a handful of drivers from their private-label speakers that were bought at Shaak Electronics. They had almost non-existent crossovers and they didn't handle much power. Add the fact that they sounded like crap and you have the trifecta.

I think I have blown one woofer, but the other is fine. Luckily, I was able to find a direct replacement because the one that came with the speakers was a special design, made to provide better bass in a smaller internal volume for sealed cabinets. The guy at Madisound swore that Phillips never made a woofer that would work in this box and the part number was wrong, but I was looking at the back of the magnet at the time.

 

[highfigh]

I think the only way to answer the question is by going through some cases. So let’s present some cases that newbies may face.

Case #1. Newbie #1 bought a pair of speakers before consulting with AH members. He said his tower speakers are rated for 50-300 Watts. He sits 4 meters from this Speakers. His average volume is about 80dB, peak is 100dB. His speakers are 8 ohms nominal, min impedance is 4 ohms around 60-100 Hz. Sensitivity is 85dB/2.83v/m. He also has a pair of 12” Velodyne Subwoofers with 500W power.

Newbie #1 asks How powerful should his amp be? 100W? 200W? 300W? 500W?

The question that needs an answer is "How loud do you want it to play?".

Almost invariably, I heard "Not too loud" which, coupled with the long hair, band T-shirt or denim jacket plastered with Slayer, Pantera, Led Zepplin, Deep Purple, Ozzy and Rush iron-ons told me "This guy needs to learn about this stuff". We would ask what they had for equipment and if it was a cheapo receiver and turntable with a small budget, we didn't just sell them something to get them out the door because they would be back soon with dead speakers and a bad attitude, so we explained that if they base their choice on what it needs to do, it won't die prematurely. We also explained hearing loss and the basics of how playing it too loud causes it to sound like crap. Some of those kids who started going there at 15 or 16 years of age were still going there at 30 and 40. I was invited to someone's house about ten years ago and as we talked, a woman who was their neighbor was talking about her husband, his siblings and some of his friends. There's no way someone with that first name would have siblings and friends with the same names as the guy I know with that name, so I asked if her last name matched and she said it was. Turns out, he still had the whole system he had bought from the store where I had worked- I left in April, 1988 and this happened in 2008.

I had one guy ask "What's your best speaker?". I asked "Best, or loudest?" and he responded with "What's the difference?".

 

[AcuDefTechGuy]

Given the speaker sensitivity and listening distance, the newb can use one of those handy peak spl/power calculators, and choose amp power accordingly. If the power suggested by the calculations seems unreasonably high for the safety of the speakers, they should consider more sensitive speakers.

Newbie#1 says he listens to volume average of 80-85dB, but there are times when the peak level may be 100dB. His speakers are rated for 50-300W.

He plugs in the 4 meters distance, 85dB sensitivity, and Average volume of 85dB into one of the Power Amp calculators (https://www.crownaudio.com/en-US/tools/calculators#amp_power_required) and it says he needs "16 Watts". But when he plugs in the max volume of 100dB, it says he needs "506 Watts".

He asks:

1. If a 100WPC Benchmark AHB2 amp is okay since his speakers only need an average of 16 Watts?
2. He can't buy new speakers, but has dual 15" Velodyne subs. Could the subs reduce the power requirements?

 

[ski2xblack]

Newbie#1 says he listens to volume average of 80-85dB, but there are times when the peak level may be 100dB. His speakers are rated for 50-300W.

He plugs in the 4 meters distance, 85dB sensitivity, and Average volume of 85dB into one of the Power Amp calculators (https://www.crownaudio.com/en-US/tools/calculators#amp_power_required) and it says he needs "16 Watts". But when he plugs in the max volume of 100dB, it says he needs "506 Watts".

He asks:

1. If a 100WPC Benchmark AHB2 amp is okay since his speakers only need an average of 16 Watts?
2. He can't buy new speakers, but has dual 15" Velodyne subs. Could the subs reduce the power requirements?

Cool, let's dig into this.

Let's compare the Crown calculator results to one of the other calculators just for the heck of it (this one, which I've compared to actual measurements and seems a bit more geared to domestic rather than large venue calculations). Let's also focus on his peak power demands, following the dictum that he wants to avoid any clipping at all. Per the calculator, his desired 100db max output would require 250 watts. Average power was in the low single digits. [This seems to be where the mht calculator deviates from the Crown, as it seems to assume more room gain/less loss per distance, which would be the case in a domestic situation...but it also gives lower power results, possibly suggesting an less powerful amp that the newb would end up running closer to it's limits.] Even with just a little wiggle room of 3db, a noticeable but not dramatic increase, puts the newb into the 500 watt zone.

The respective calculations are at least in the same ballpark, so let's apply it to his specific amp/speaker. While that Benchmark seems a worthy SOTA amp (current dumper output stage a la Quad, and some of the lowest measured noise performance in existence? Sign me up!),the newb may very well run it beyond it's limits, particularly after a few adult bevvies. Per both of our calculations, his max peak power requirements are beyond the Benchmark's capability. His speakers are on the lower side of the sensitivity spectrum, with a max power rating of 300w, whatever that actually means. That all adds up to the reality that his choice of gear is simply not geared for high output. If he attempts to make it do so he's putting his speakers at risk.

Employing the subs and bass management would help, if only marginally when it comes to power. It would offer some protection from over-driving the woofers, but is no guarantee he wouldn't clip his amp (which raises average power levels as described in the linked article) and risk frying his tweets.

But like you said yourself, it depends. If he listens exclusively below 100db at his chair, he's probably fine. Any limited, transient clipping would probably sail by without the newb even noticing. The benchmark's 100w will only get him 96db at his chair before it clips, per the calculator, and that's still pretty loud.

Also, the Benchmark is a relatively low gain amp, so the newb better have a pre than can swing some proper voltage or he'll never get his amp's full output capability. Frankly, as nifty as that benchmark amp appears, it also appears to be geared for someone with a fancy pre-amp, using far more sensitive speakers (think KHorns),where dynamic power requirements are low and it's vanishingly low noise may actually matter-it really wouldn't on speakers as insensitive as those in this scenario. It may not matter under any circumstances, as we're well into "bee fart in a hurricane" extremes.

Assuming the newb wasn't suffering from a bad case of Spastic Wrist Syndrome (thanks for that @highfigh),he would probably be better off using a less expensive, less exotic amp of the 200-300w range. Given the distances involved, his situation seems to justify that much juice. Such amps typically have adequate dynamic reserves, certainly as much clean power as the newb would ever want to subject his speakers to. If that still wasn't loud enough, then he needs to consider more sensitive speakers.