Agree. Analog power output meters on amps show a very smoothed out average power reading. Off topic, but I measured the amp consumption of my outdoor A/C compressor unit with a peak reading amp clamp. When energized, the starting current can hit over 110 amps @ 240V! Quickly settles down to 8.5 running amps! Funny to think that once the compressor stabilizes, it could be kept running using a standard ole lamp cord? So, picture an amplifier driving a speaker. When a loud percussive thwack from a drum comes down the line, the amp may be asked to deliver a short peak of well over 200 watts for milliseconds while the analog meters (if amp has them) may show a peak of say 10 watts. That's my analogy.
Adequate power makes the peaks come through without distortion. One factor that makes much power necessary is that the sound level increases only 3dB by doubling the power and is barely audible. Thus if you listen to music averaging 1 Watt, your peaks could hit above 30 Watts with typical mastering headroom before clipping.
That comment of Headroom is the real takeaway point. In my old AV setup, the Rel Gibraltar G1 had a massive amount of headroom, just couldn't make it bottom out.
I find with my speakers I draw around 60-75w from the wall with the main speakers, now with the subwoofers, I draw around 700w from the wall, the main speakers come through clear, and the bass fills in the rest, and I love the way it sounds. It gets very loud within this small room
In the 70s, I had a Phase Linear 700B powering two Klipsch LaScalas. For laughs I would take an old hand sized portable transistor radio, connect the speaker wires to the LaScalas and could drive them to remarkably loud levels. With the 700B, I didn’t listen to louder levels (unusually), but the ease of reproducing dynamics showed up in vastly better music.
Back in 1979 I too had a Phase Linear amp (Dual 500) powering two Roger Speaker Lab floor speakers. When my Dual 500 had an issue I hooked up my old 1975 'Marantz' AM/FM/Cassette "Boom-Box" to the RSL's and down low they sounded good but cranked up the distortion was horrendous. No headroom wattage as that Marantz only had maybe 25 watts. Side note, Bob Carver rebuild the Dual 500 free of charge, local Seattle drop off and pickup.
A lot of the old speakers were more efficient as really high power amps weren’t common. But, the speakers were rated at lower rms power. Now high power amps are plentiful and speakers are rated for much higher power, but at the expense of efficiency. Many people think you need thousands of watts to get a loud system. But, with an efficient system you can get very loud with a surprisingly little power. And, sometimes the speakers sound better because they don’t end up being very stiff from the extra structure to handle high power.
I replaced my 200 W/ channel (8 ohm) power amp with a 100 W/channel amp with a quieter noise floor, lower THD, and a higher slew rate. In a blind listening test, to me on exceptionally good recordings the 100 W amp sounds the slightest bit better than the 200 W amp at normal listening levels. It isn't just the power rating that matters. I haven't done it, but it's possible that a really good 25 watt Class A amp might sound even better (unless your speakers are very inefficient).
I have a Cary Audio CAD-300SEI single-ended triode integrated amplifier. It only outputs 15 watts total but with some 93db speakers the sound is amazing.
We had a Fisher Radio Coronet Hi-Fi (1950-1954). Mono yes, 25 watts. New Hi-Fi including headphones. They sounded pretty good with my Sony TFM-121. So I AM-FM radio. So I decided to compare it's amp to the Fisher. Granted 1/8-1/4:Watts. But still the comparison. I tuned to a good FM classical station. With the speaker connected to 1/8 earphone plug.I plugged it in. It was just as loud, only it had base. Not enough to blast out of the room but it did compare efficiency. That explained why we were able to listen from 3 rooms away. I have that Hi-Fi plus a same brand Stereo. Re-capping would be fun. These are equipment which the owner of the radio company retired built the New York Philharmonic a concert hall; Avery Fisher Hall.
3:02 - This inrush of current scenario is only valid for solid state power amps! With a tube amp, if that woofer's impedance dips at certain low frequencies, the voltage delivered to the speaker ALSO dips!
As a guitarist over 9000 but from all the audio oriented amplifiers that I built the one that I love the most is Hiraga’s le Monstre only 2*8w. In that case the power supply matter more than the watts
I like to use three amplifiers. I have 120w for bass (1200 Hz). If any part clips, it's much less noticeable. In practice, my speakers are efficient enough that I never noticed distortion.. I used to live in the country, where I could crank it up. Never had a power problem.
I've got a pair of PS Audio's M700 amps, and they're way more power than I'll ever need. I have Dunlavy SC-V speakers, 91 dB sensitivity, so 700 watts into 4 ohms is overkill, but it sure sounds good!
In my experience. 85 RMS power was the cut off. Now I listened to rock music. Most of the time loud in the 70's. Anything less than 85 watts wasn't enough. At 85 watts was just barely making the volume without distortion. Switching to the Sansui BA 3000 had plenty of power. 170 Watt RMS. And then the Dynaco stereo 400 and 410 was just perfect. Though the Sansui had a slightly smoother sound. Maybe because of the subsonic filter which was a great addition to that amp. I'd say an amp with 200 watts RMS is just right.
I got a great response from the VP, of a speaker company, who was demoing their products. I told him that I had an Arcam with 50 only watts and asked if it would drive the speakers, which I was interested in. He said "it will drive you out of a lease, if you let it". I laughed and bought the speakers.
Decent peak hold meters would show how much headroom that you are needing/using. The BBC used PPM (peak programme meter) to make sure that the audio chain out to the transmitters didn’t get over modulated or the pcm distribution didn't reach clipping. The PPM were logarithmic (sounds like the Macintosh are too) but held the peak for a short time before a slugged decay. Not as much fun to watch, but essential for me at the time (I left the BBC years back).
I used to own an old Moss meter .and I had and adcom gfa555 and I would never go passed 50 watts and it would be tolerable in the room I could never stay in the room at 100 watts peak I could be outside and hear the music from 3 blocks away and that's not a stretch ..Reserve power is essential for good realistic sound replication .Those Adcoms were built like tanks and sounded really good .So were my Klipsch lascala and my heresy ...Now I have had to downnsize .Married life and space become an issue ..One day I will go back to my old listening room set up with one of your newer systems ....God willing !
What is usualy underestimated is the impact of listening room on loudness achieved from speakers. It is easy noticed when we take our speakers far outside in open space, hang them 2 meters above ground and then from distance 1 meter check efficiency with 1 watt power . That would be real 88dB because this are conditions for tach data. In such conditions power 100 Watts could be considered moderate. Because walls reflect and focus sounds inside That is why in comfortable listening inside I observe atonishing even me 1/4W, Then I decided to bulid mini tube amplifier 3W and it is not sufficient only on that reason that I require deep loudness correction and 3 W for correceted 30 Hz even in silent listening is at short moments distorted - the same for amplifier and for 3 W speakers too so I need to limit low range. But 15W tube amp and 15W speakers are ok.
Thank you for being so accurate and understandable when explaining. I have a question and I hope I can get an answer or direction finding it. What is your opinion about “Celestion 15 floorstanding speakers” . I can’t find any details about them. So I will appreciate to have your personal opinion if you are familiar with those speakers. Thank you. 😊
I like more power. I have the perfect amps to demonstrate the impact. They are Transcendent triode monoblocs. They produce 110W. With half the output tubes, 25W. People run them with half the output tubes to save heat in the summer. To me they sound the same, but at 25W they don't have the same authority. Less full. And the bass is thinner. Everything else is the same. Same gain. Same input stage. Same circuit. I far prefer the 110W even though my cost of tubes and power is 2x.
the question I'm wonder and elephant in the room is how does sensitivity effect sound quality, the way I think it might work is that the more efficient a speaker is the more the rooms acoustics vibrations effect the cone movement and overall sound and that's why something like a loud car environment has a lower efficiency and has a stiffer harder to move cones requiring more power in the electromagnetic voice coil to create the amplitude and SPL 5:04 you describing the THD and the Squaring of the sinewave when amp input impedance/volume is set too high
All I know is that I found that 90 and 100db is what's needed to really gets my speakers moving. To get to that I have 3 amps pushing out 2300 wats at 4 ohms but I do like to have a lot of head room.
I assume you tri-amp. I get by with 120, 120, 60 per channel with my JBL 4343s. They can be louder than any concert that I've been to, which is sufficient.
On my front loaded horn pa system I can get 100db at 6 feet away with 1 watt (that's not a typo). With 2300 watts I can do a 400 person dance club playing bass heavy EDM music (bass levels hitting 134db's right up front, 105 dba throughout the crowd for mids and highs). Efficiency matters when it comes to watts which is why speaking in terms of watts is just useless. It has no bearing on how much sound is coming out of a system unless you know the efficiency of the system and amplifiers don't put out watts anyways. They are current limited voltage amplifiers. They put out a maximum fixed voltage and will maintain that voltage until they run out of current capacity. Your 8 ohm speaker isn't 8 ohms everywhere, its actual impedance will vary from 8 ohm all the way to 30 or higher ohms depending on frequency so wattage ratings of amplifiers at a given impedance mean nothing either unless you are driving heating elements (resistors) instead of speakers.
For home use for highs and mids usually 50 -100W is enough. For one subwoofer I would say 500W is quite enough. I found more powerful speakers and subwoofers sounds much better and warmer even on low volume. I would say it depends on speakers, enclosures efficiency and area the speaker is playing in. Its quite weird question and its the same as asking how fast car I should buy...
I have a fully active system, my tweeter amps are single watts, my midrange amps are in tbe dozens of watts, my woofer amps are in the hundreds of watts, and my sub is in the thousands of watts.
There is no increase in voltage requirements at resonance unless you want to push up the output there. See your How can power double into 4 ohms video from the other day, voltage IS the signal, current is as required.
The average wattage is not the question. As you say pretty right the peaks are the question. You need as much watts as you can get to prevent clipping of peak levels. Such clipping is not obviously audible but they can change the sound quality. Even if you listen at a average power of 4 watts you can get peaks of several hundert watts if yor sound source has a dynamic range of 60 dB wich is not very much. Studio mix down master tapes can go up to 80 dB. In this case if yor amplifier is unable to deliver those peaks you'll get distortions in resulting in a kind of fizzy sound. As i mentioned it's not obviously audible but if you do a A/B comparison with a high power amplifier like a ReVox A740 or similar equipment you'll hear the difference clearly.
i test my speaker by sinewave, and the part of the frequency band where my limit factor is, that is the deep bass for me. so i put 16hz thru them until they start to distort, then look at the wattage used on my power amp for a while. that number is the watts i need and use at maximum for that speaker(s). might be more complicated for some other system. mine is all sealed speakers and subwoofers, with increasing gain as the frequency get lower.
in my 50+ years of Hi Fi starting with a 12w per** Pioneer + Dynaco 25 spks to , now. Outlaw 110 w per & KEF's. I've come to conclude that for me , 60 w per is OK. ' Normal size room say 200 sq ft or so . ** that's the conservative '1970's. both ch driven @ 8 ohm, 20 -20,000 HZ rating ). there are different ones used.
I think the music genre makes a difference if you hitting the lows consistently and in force like say EDM I think then it's going to use a lot of watts, I also like sealed subs with no port and those suck down huge amounts of power. Class D dedicated for the job with many hundreds of watts. Continuous mid bass in the 70-500Hz range also uses a lot of power, not hundreds of watts but maybe a hundred watts. In the upper registers say human voice only a few watts are needed to go very loud. Also how layered or dense the music is makes a difference, I like Metalica and Tool which benefits from power. Diana Krall not so much, no disrespect intended she is a wonderful talent and performer.
I've always use the truck analogy and how it relates to towing. Do you need 500 pound feet of tourqe to drive on city streets? You do when you tow a boat up a hill....
Don't high power amplifiers require more attenuation than lower ones for the same volume? If I listen at low volumes I would set the volume too low, so less S/N ratio. Also, amplifiers usually reach least distortion near full power..🤔
When you say a factor of 10, do you mean a power amp with 10x the max continuous wattage rating of your speaker? e.g. 100 watt speaker you would need 1000 Watt amp?
Crest factor for most acoustic recordings is about 25 dB. Ie, you need 300x more maximum power than average. To have average 80 dB SPL at 3m, you need 90 at 1m, and 115 max. To produce peak power of 115 dB by 88 dB per W speakers you need.... how many?
The corresponding factor is the speaker sensitivity. 3 decibels more sensitive then your power can be cut in half. If you have a pair of speakers that are just 3 decibels more efficient than the 88 db... at say 91db... now a hundred watt amp could get quite loud one advantage to a smaller amp that puts out under a hundred watts is that only two transitors will be needed in the power output stage for a typical class AB push -pull amplifier. It's just a simpler curcit . There are some benefits from that. I believe a cleaner signal at low power and certainly cost.
@@richardl6751 yeah this is the beauty of having sub woofers. Not relying on you main amplifier/s (I use multiple pairs of low power amps...all AB mosfet...it's a lot of time setting up and fiddling...but the results are worth it) to power that bottom end takes a big strain off the rest of the system...class D is getting pretty good now too...not a bad choice for those subs anymore.
The whole concept of "headroom" seems logical, but in practice, it is so misunderstood that it could be considered "placebo". "Peaks clipping" is a bogus concept from the audio press and hearing it does require advanced listening hygiene. This means, the first investment is in your listening habits not in horsepower. Then one needs to realistically figure out what is really needed for the typical and extreme volumes used in your room. I simply do not see "intelligent" customers with inefficient speakers using fleawatt tube amplifiers.
Thank you, I didn't want to be the one to say that! My Infinity SM152's are 102db, which is light years more efficient than 88-90db. It seems like it would be like dragging a 1000lb weight behind your car, you would have to use ALL your power to get any speed. Same as with inefficient speakers.
Every doubling of power is adding 3dB to the sound level. If the mastering is with 15dB headroom before clipping, you need to double 15/3=5 times. 1 Watt doubled 5 times is 32 Watts.
@t. I. go with this myself, so I'm OK with 60 w per ( conservative mid '70's rating - both ch driven @ 20 -20,000 hz) )- in a ' normal' size room, say 200 sq fit. with the note back in the day 20 w receivers from good companies like Pioneer were plentiful. now, an 'Econo ' $200. Yamaha has 100 w per..... so no worries.@@ThinkingBetter
@@ThinkingBetter Thanks, so during mastering they add 15db. I didn't know that. So 5x doubling power makes sense. I ment 32w not 36w, maths is not my strongest. Anything over 10 and I run out of fingers.
@@stephens2r338In Paul's example of picking between 5X and 10X power then yes his minimum would be about 36 watts but I think he'd pick an amp around 150-200 watts for loafing around at mid levels. I think he has 10 fingers too. ;) When I was young I too was into the "AMP HORSEPOWER" wars. I had an amp with 500 watts RMS per channel, 1010 TOTAL watts. Rarely did I ever crank it above 3 or 4 on a 10 scale.
Thanks to everyone for you replies. I have very sensitive speakers, 96db.I have worked out that i am using around 0.2w when playing around 80db. I use a relativity cheap 50 w tube amp that works great. I have used large ultra high end mono 300w amps on them too (10x the price) but they didn't sound as good. I wonder if to use a car engine as an example that it doesn't matter how large the engine is if all you ever use is less than idle and can it even run properly.@@davej3487
My system i have a Yamaha 3500 power amplifier 350 + 350 Watts per side @ 8 ohms and a yamaha Q3021A 31 band graphic equilizer. While i never use that amount of power and i find that even in the lounge room i'm only using a couple of watts at best. BUT i have plenty of head room for demanding music or dvd. Speakers are a 3 way set up, 15" bass 6.5" for the mid's and a 1" for the top end. Nice sound with a far bit of power behind in reserve. I look at the power rating of a amplifier, a bit like two cars, one is a little vw trying to pull a large caravan around and the other is a large 4x4 pulling the same caravan. What car would do the job of pulling that caravan around on a trip around America. The vw may do it but struggle on the hills and high spead freeways, and you may find that the vw is running close to maximum power ( HP ) were as the 4x4 would have little to no problems on the same trip.
If your listening to the Beatles you don't need much for as great as they are the recordings are trash these days. If your listening to modern digital recordings, the more the better. The more different types of speakers the better, the more different eq's the better. Find the right medium to suit your tastes.
100dB? 110dB? Those are instantly clamp your hands over your ears and run out of the room levels. Nobody who values their hearing should be listening that loud. I'm pretty sure mechanical SPL meters went out decades ago. Modern digital meters don't have ballistics issues and can read peaks accurately.
Ive been an audiophile for over 30 years. My studio monitors are rated at 102db @ 1 watt input. I have 2 pairs of them double stacked 8 feet tall andi drive them with 2 Adcom GFA 5802s that provide 300 watts per channel into 8 ohms per speaker and guess what?? I listen to them at rock concert sound levels. Always have and always will. My hearing is great and when people come over, their hair stands up on their necks. With only around 128 watts input, my speakers are singing at around 126db! Yes, rediculous sound levels, but its in a huge room and sounds incredible. Teamed up with 2 SVS 12inch powered subs with 2000watts of available power each, its able to reach rediculous sound levels and still super clear. For jazz music,i back it down to about 105db and its at its warmest and rich sound. Ive always listened loud, ive owned the Adcoms 20 years and never had an issue, ever.
When discussing loudness, 100dB, 110dB is essentially meaningless without an associated frequency. 100dB of a low frequency like 20hz, is only 20dB above audibility. That's very low, barely discernible. Whereas 100dB at 3khz could be brutal in a room with poor acoustics.
@@vegaslimoguy2376 I too listen quite loudly most of the time at home. (2kw active 3-ways, plus four 15's, four 18's for subs ... about 10.8kw total for two channels plus subs) Even in my 60's, a career mixing live, high dB car audio in the late 70's, early 80's, brutal construction noise (metal chop saws, etc), I'm still good to 12.5k! Rock on.
@@vegaslimoguy2376 I suspect you might be the proud owner of 2 pair of Infinity Studio Monitors with the 15"s (SM-152's or equiv)? I myself have 3 sets of the Infinity's, (although 2 pair are not in service needing refoamed), and I run a Hafler XL600 @ 305wpc/8ohms 470wpc/4ohms. If it's too loud, you're too old!! Rock on!
