Thank you sincerely to all the posters for educating me with your wisdom and experience - you guys are a source of great info...
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Hi @agwca , It is not true. Every particular room has the parameter Critical Distance: https://en.wikipedia.org/wiki/Critical_distance "Critical distance is, in acoustics, the distance at which the sound pressure level of the direct sound D and the reverberant sound R are equal when dealing with a directional source. " For typical listened room critical distance can be just 1-2 meter. And Critical distance is different for different frequencies. If the distance from the speakers is longer than Critical Distance the sound pressure remains similar to sound pressure on the Critical Distance. http://journal.telfor.rs/Published/Vol2No2/Vol2No2_A6.pdf Regards, Alex. |
Doesn't SPL also depend on listening distance and room acoustics? So, if a speaker is 90 dB/1 watt at 1 meter and you sit 2-3 meters away from the speakers, then what you are hearing is 87 or 84 dB. So, if you want to listen at 90 dB, you would need 2 to 4 watts, or more. So theoretically, a 40 to 50 watt amp capable of low distortion should do given transients. If you want to pound your ears into oblivion, say starting at 105/102/101 dB, then you would need 16/32/64 watts using the above proportions. So, transients could demand 160/320/640 watts to keep it sounding "more live"? So, for really loud music, a really powerful amp may come into play. I typically listen to music at under 90 dB at more than 2.5 meters from speakers so a lower power low distortion amp should do. My amp, a Hegel h160 does nicely but it is over kill for my speakers, Focal 807Ws which were less than half the price. The speakers also do well with a really inexpensive class D with of course less quality than the Hegel. This little class D does seem to sound better in some ways to other AB amps under a grand I have tried. Depends on the level one listens, the Hegel and Focals work very well where cheaper alternatives would do for many. I like stand mount speakers but if I were to go with a floorstander, I'd like to try Tekton Lore Reference. At 44 lbs, their doable. At 96 dB, a smaller amp or tube could do. I do stay away from low sensitivity speakers as a rule seeking something around 90 dB. Other speakers are Triangle Zetas for desktop. Less resolving, a bit more sibilant than Focals, less bass, but they do nicely as well. Don't even need a sub to enjoy them both though a sub can fill in the basslines. Other very efficient speakers I have not heard , Zu speakers seem to have a following as do others. Choices. |
Atmasphere, Is there a way to determine an amplifier's lowest point of distortion apriori or is an empirical issue?If the specs are published, its easy, if not, a distortion analyzer is handy. But as I mentioned, with most amplifiers this is about 5-7% of full power. Having unlimited power is great, but the practical issues around that are profound. If you need that power because you have inefficient speakers, thermal compression will prevent you from ever playing the system all that loud and getting the dynamic contrasts right. One problem that is epidemic with higher powered amps is poor application of loop negative feedback, owing largely to inadequate Gain Bandwidth Product. This causes such amps to sound harsh due to higher ordered harmonic distortion. This is why efficiency is important in loudspeakers, and there is no reason why a speaker has to trade off anything if resolution is a higher goal. The speakers I'm running at home are 97.5dB, the first breakup of the midrange driver is at 35KHz. So its very fast and smooth. On such speakers you can use lower powered amps and still achieve sound pressures well over 100dB. |
I learned my lesson long time ago, there is absolutely no substitute for having the headroom needed when you need it! I don’t have the Telarc 1812 Overture, but I would expect it to be exceedingly rare for any recording of music to have a wider dynamic range than Stravinsky’s "Firebird Suite" on Telarc (Robert Shaw conducting the Atlanta Symphony) and Prokofiev’s "Romeo and Juliet" on Sheffield Lab (Erich Leinsdorf conducting the Los Angeles Philharmonic). I have observed the waveforms of those recordings on a computer, using a professional audio editing program, and found them to have a dynamic range (the difference in volume between the loudest notes and softest notes) of about 55 db, which is simply incredible. Correspondingly, at my 12 foot listening distance the softest notes are reproduced at SPL’s of about 50 db, and the loudest notes at about 105 db. My little Pass XA25, which after leaving class A can probably provide around 100 watts into the 6 ohm impedance of my speakers, has no trouble at all accomplishing that with zero evident distortion. And likewise in the case of the 70 watt VAC Renaissance 70/70 MkIII I used previously. My speakers are rated at 97.5 db/2.83 volts/1 meter/6 ohms. As with many such specs that rating might be a bit optimistic. Regards, -- Al |
I found that interesting since I had read the output current of other brands of amplifiers. Not sure what to make of the lack of response. Amplifier current ratings are among the most useless and misleading of specs, IMO. What they usually represent is how much current can be provided into a dead short (zero ohms) for some unspecified miniscule fraction of a second. And in some or many cases they represent what the amp’s power supply can provide for that miniscule fraction of a second, rather than what the amp’s outputs can provide. See this thread: https://forum.audiogon.com/discussions/current-limit-onset-definition?sort_order=asc Regards, -- Al |
Okay, One does need a lot of power to get to power levels so high as to melt binding posts. If that is the requirement for a suitable listening level, get a very high-powered amp, because power is relatively cheap to attain, while high quality in other aspects is not so cheap. I don't listen at that kind of level and I don't include as a priority the capability to play at extreme levels; I insist on the system sounding dynamic and lively at modest listening levels. It hardly matter what level the cannon shot in the 1812 Overture should be reproduced at--the dynamic range of the recording limits how loud it will be when the volume level of the rest of the piece is played at realistic levels. |
Underpowered amps /receivers,...are detrimental to tweeters and midrange. Having enough power, for crescendos, ending spikes, is a must. My speakers are rated a max of 250W peak I’m sure, I use McCormack DNA-750s’ rated at about 650W @8 ohm, and a lot more into 4ohms! I learned my lesson long time ago, there is absolutely no substitute for having the headroom needed when you need it! when you push the volume at times, you will need the power and headroom as to not send distortion to speakers, from overdriving a low watt amplifier into distortion. been through more warranty situations anyone should go through, from lower watt amps. When I hit my first high powered amp, no more blown tweeters/mids/woofers. after I melted the binding,posts to red and black puddles of plastic from my onkyo m-504. At 165W @8 ohms, I went to a pair of pro amps, Carvin dcm-2500’s in bridge mono, for the good price and watts. They were not reliable, but the first year, I never heard such effortless sound, peaks, airyness, it was an epiphany for me. have never strayed from a minimum of 300W RMS, never an issue since. Again: https://www.youtube.com/watch?v=Sg14jNbBb-8 |
I’ve never heard it, but it’s said, to reproduce the cannon shot in the 1812 Overture, an amp needs 700+ watts to reproduce it. I'm gonna go out on a limb here and say to reproduce a cannon shot you need a cannon- as otherwise in terms of power its logarithmic and you can forget 700 watts, as that is only a measly 3dB more than 350 watts. A gun shot is 140dB, a cannon certainly louder than that. But even 140dB, again, its a log scale. Say your speakers are 100 dB at 1 watt. 10 watts then is 110dB. To get to 120dB calls for 100 watts. You can see where this is going.... 130 dB, 1000 watts. 140dB 10k watts. Again, that's a gun. Not a cannon. I've heard- felt- the cannon at Gettysburg. If that is the criterion having enough power is the least of your problems. |
@handyman said, "High current amps are what is needed, not necessarily high wattage amps, unless you’re pushing high efficiency horn loaded speakers, or something like them, although they usually go hand in hand." I agree, while recently researching class D amps I asked PS Audio about the output current of their M700's Here is the reply.... "The M700's run 350 w at 8Ω and 700 w at 4 Ω. Of course there are times it will peak above this but this is a general continuous wattage. I hope that helps. Please let me know if you have any other questions." I explained that I knew the power rating, I wanted to know the current and received this response..... "I did not have this Spec so I went to the Designer of the amp and this is his reply. I found that interesting since I had read the output current of other brands of amplifiers. Not sure what to make of the lack of response. |
Simple fact is that if you can get a more powerful amp to sound as good as a lower powered amp through the entire spectrum more power is better. Problem is that many higher powered amps dont sound as good as their lowered powered alternatives. This seems especially true of S.S. amplifiers. Part of this must be an issue of circuit complexity. What irritates me more than speaker efficiency is the issue of low impedance speakers. To me there is no reason for the existence of low impedance speakers! |
The 6B4G is a 2A3 with a different base.A minor point, but for the record it's probably worth noting that the 6B4G is a 6A3 with a different base. Both of those tubes, in turn, are electrically similar to the 2A3 except for their filament voltages and currents, which are very different (6.3 volts/1 amp in the case of the 6B4G and 6A3; 2.5 volts/2.5 amps in the case of the 2A3). Regards, -- Al |
You may be correct about the cause. The tube amps are described as: a pair of tube monoblocks using the 6B4G tube in push pull configuration. The 6B4G is a 2A3 with a different base. These amps put out around 16-18 watts. Built on Magnavox console chassis with the 50’s/60’s Magnavox transformers. The parts are industrial but quite good quality. These were built in the 90s or early 2000s and were formerly owned by Charley Kittleson of Vacuum Tube Valley. Tubes are 6SL7, 6SN7, pair 6B4G, pair 5R4 per amp. The other amps are Jeff Rowland 501 with separate power supplies. The external ps make the amps sound exponentially better, to my ear, than without. |
Hi @bob0398 , Most of speakers (Tannoy, Klipsch,...) have overstate sensitivity specification. Even vintage speakers like my Altec 604E have 102dB/m by spec, but in real live just ~97-98dB. On other hand a lot of tube amplifiers sound slow. It happens not because they have low power, but because a bad design. For example, a lot of 300B SET amplifiers use 6sn7 (or even less powerful) driver tube. The result is bloated bass and slow sound, bad transient . Regards, Alex. |
Atmasphere, Is there a way to determine an amplifier's lowest point of distortion apriori or is an empirical issue? A personal observation: I have a very powerful solid state amplifier and a small tube amp (over 1000W vs. 10W) and I've recently discovered I prefer the sound of the big amp over the little one with my very efficient speakers (>99db). I recognize that there are a lot of variables at play here. |
+1 for Cakyol, Mapman,Arctikdeth,Atmasphere and others. High current amps are what is needed, not necessarily high wattage amps, unless you’re pushing high efficiency horn loaded speakers, or something like them, although they usually go hand in hand. Dynamic headroom is the main reason for a high powered amp. I’ve never heard it, but it’s said, to reproduce the cannon shot in the 1812 Overture, an amp needs 700+ watts to reproduce it. I play many difference genres of music, sometimes at high dB levels. This is when the extra power comes into play. I love class “A” biased amps. They’re quick to reproduce the music and it sounds amazing. This is not to say that a smaller tube amp feeding high efficiency speakers isn’t happening. Even a warm SS amp will suffice. For my tastes, I prefer the hefty class A amp. We all have our preferences. |
I like cars...let's go back to the car analogy. A Porsche GT2 sold to a person that is legal on the street has to be de-tuned to race. However, horsepower isn't breaking or handling and a high horsepower car without a good breaking and suspension system is limited to being fast in a straight line or in other words drag racing. A Miata with the right driver can challenge many high horsepower cars because its light weight and balance. Not all amplifiers have the same circuitry and components and may not excel in reproducing all types of music...they could be great at a tornado warning not music. |
As far as the car analogy goes, My 350 hp supercharged S2000, is far less tractable, due to requiring 7000-9000 engine speed, than are most turbo cars, such as my 15 psi 280 hp MR2. This autocross suspended MR2 and most Porsches are great without attracting attention with a 9200 rpm amplifier terrorizing the neighbors. |
Forty years ago, When I "downgraded" from a Phase Linear 400 to a 100 wpc Audire, it was a major improvement, with subsequent improvements since, pretty much unrelated to power. However! The best home system I ever heard was a pair of actual B&W Nautilus speakers, which require a highly damped 350 wpc amp for each if its eight drivers. It was exactly powerful enough. This owner used Mark Levinson, back in the day. B&W had their Classe division make amps for these still extant. special order speakers. I wish Audire could power them, assuming Julius (Siksnius) could still create his magic, plus he preferred 100 wpc amps and speakers that could use them. It is not all about power. |
arctikdeth, Regarding Class D, that was my impression too of several such amps I've heard, but, that seems to be the case with most other solid state amps. The old adages of solid state sounding grainy don't apply any more, for me it is lifelessness which makes one try to counteract that sense by pumping up the volume. I like listening at more modest levels, which is why I go with tubes. |
So, at least for the 2 manufacturers above, higher power is possible & better :-) It is only the cost that will be the negative aspect.From a designer/manufacturing/engineering point of view I can tell you that this is simply incorrect. Its much easier to build a low power amp than a large one, and even though in a larger amp you can have the advantage of paralleled devices to minimize individual device aberrations, the simple fact is that the added complexity is a **frequent** downfall! I've also mentioned several times on this thread one of the peskier issues dealing with the myth of more power which is outlined in @pragmasi and @shahram 's posts above. If the amp is always operating ***below*** its minimum distortion level, you won't be hearing the best out of the amp or the speaker. For this reason the amplifier power has to be matched properly to the speaker efficiency such that the amplifier is doing its best work at normal listening levels. This isn't ideal but we live in a real world that does not care what we humans regard as ideal. So you have to be pragmatic and recognize that amps aren't perfect! Now anyone whose read this far may have picked up on something- that in addition to a distinct advantage in terms of sound quality to matching the amp and speaker (a powerful amp working with a lower efficiency speaker and a higher efficiency speaker is better off with a lower powered amp), that also unlimited sound pressures are often not possible in many listening environments. Since thermal compression in loudspeakers is a very real thing, there is an obvious advantage to working with easier to drive speakers since they will play the dynamics in the recording better. At the same time because the amp isn't working as hard, it won't have to make as much distortion either. |
I thought I needed a lot of power for my Maggie 3.6's and had a 540 watt class D. The room would shake and it was fun to show off but no way to listen to music that loud for long. I have 60 watt Pass class A amps with powered subwoofers. Much more musical, I don't need to make the room shake any more so there is plenty of power for my listening levels. There is enough power to make the Maggies come alive when I want to open them up for a short while and the inner detail and blackness of the background is really appreciated with the Pass amps. And I have found that the pre-amp makes a bigger impact on the quality of sound at higher levels than the amplifiers. A big amp makes a noisy pre amp sound more noisy especially when it is driven. |
@atmasphere You really nailed this question. It's all about matching amp to speaker efficiency. And amplifier has a sweet spot in it's distortion vs. power curve. I've got a 500 watt integrated amp (which I bought in 2015) that I now realize is totally unnecessary with my current speakers, which have 89db sensitivity. I'm probably only ever using 1 of those watts because I rarely listen over 90db in volume level. I'm looking into some 25-50 watt class A and tube amps to better match my speakers and on focus on quality watts, not quantity. |
If you're speccing an amplifier you need to go for the amount of power that you'll actually use plus a small amount of headroom. That doesn't sound very helpful but in order to optimise your system properly you need to understand the gain structure... if you've got a 1000W system and you never turn the volume higher than 30% then you're hearing more noise than you need to because every time you attenuate you move the noise floor closer to the signal level. This is true regardless of the quality of the components you are connecting together. If you factor in the trade offs that need to be made when designing an amplifier then you'll work out extra power will either drive cost upwards or other qualities (such as sound quality) down. If you follow the instructions in the thread I previously linked you can work out the amount of power you use and optimise your choices. I'm happy to explain more if anyone wants. |
atmasphere, " We are one of the very few manufacturers that make more powerful amps that actually **do** sound better than our smaller ones" So, it is indeed possible to do so. Pass Labs is another definite manufacturer in this regard. So, at least for the 2 manufacturers above, higher power is possible & better :-) It is only the cost that will be the negative aspect. |
The reason the industry moved away from high efficiency has a lot to do with the large size of typical high efficiency speakers.Not all higher efficiency speakers are all that large. Many 'full range' drivers can be quite efficient yet the cabinets are reasonable sizes. ALL OTHER THINGS BEING EQUAL (That is the part people seem to be missing) a higher power amplifier will always be preferable. It will run less stressed and have much more headroom.The first statement is correct. The only problem is things are never equal. The second statement is simply false- it subscribes to the idea that 0.005% THD is 'low'. Its not low if that distortion is all higher ordered harmonics, owing to the fact that the ear uses these harmonic to sense how loud a sound is. It is this simple fact that is why solid state has a reputation for brightness- that's not coming from a frequency response error, its caused by distortion. Why is everyone assuming that the make, quality and characteristics of an amplifier are changing when going to higher power ?Because they often do. Given everything else being equal, there is no argument except maybe just the cost and power consumption, that going to a higher power is always better.The 'Given' isn't a given. One problem you can have is that higher powered amps usually also have more gain. If you put that amp on a higher efficiency loudspeaker, the noise floor can be annoying, the additional distortion (due to the amp operating below its point of lowest distortion) notwithstanding. Do not equate going to a higher power, with also changing the quality. The two have nothing to do with each other.In this regard your statement flies in the face of conventional wisdom which is based on experience of many many people over decades! As a manufacturer we deal with this all the time: "Don't your smaller amps sound better?" Ask any manufacturer- they will tell you they get this question often. We are one of the very few manufacturers that make more powerful amps that actually **do** sound better than our smaller ones- this owing to how we scale up our power levels. But most solid state and nearly all tube amps sound better in their smaller embodiments, so long as the speaker allows for the lower power. |
Why is everyone assuming that the make, quality and characteristics of an amplifier are changing when going to higher power ? The question asked, did not imply that. Given everything else being equal, there is no argument except maybe just the cost and power consumption, that going to a higher power is always better. So, what that means is, if you have amplifier model line A, with characteristics X, if you move to a higher power amplifier with EXACTLY the same characteristics, there is NO negative. It still is amplifier with model line A, with exactly the same characteristics X, just higher power. There is not one argument here which can defend that lower power is better in this case. Think Pass labs for example, like upgrading from an XS150 to an XS300. In this case, in fact the quality is most likely even BETTER since the latter comes with a beefier power supply. In the case of the Porsche examples people have indicated above, that would be akin to getting the same car, still a Porsche but now with a 400 hp engine than a 180 hp engine. I admit my first example of having a 500hp car did not emphasize that point. Do not equate going to a higher power, with also changing the quality. The two have nothing to do with each other. |
My main system cast offs often end up in one of my other systems. For a while I had my 440 watt per channel Wyred 4 Sound ST-1000 MKII in my bedroom with my 102 dB efficient Klipsch KLF-30 speakers. I'm pretty sure that was too much power. For that room and for what the system was intended for (mostly listening at quiet volumes before bed/sleep). If not for the different gain settings on my ARC LS 26, the music would often have been louder than I wanted it, even at the lowest volume setting. The KLF-30's have found a new home and now I have some much less efficient (and much smaller) Canton monitors in there. The ST-1000 MKII was in my main system for a while and was replaced by Rogue Audio M-180 monoblocks that are "only" 180 WPC. Great improvement in sound quality (not that the W4S amp was bad), and more than enough power. There's a 30 WPC that I've been eyeing the last couple of days. 30 Class A watts. I'm going to Pass on that one (see what I did there?), but watts are just one factor to take into consideration when it comes to amplification. |
Hi @larryi , I'm not against to use, for example, small monitor speakers with sensitivity ~88-90dB/1W in 100-150 sq ft room. But in this combination even 300B SET will be enough. I think the very popular but wrong way to do - using big low sensitivity (< 88dB/1W) big tower speakers in a big room. In this situation need a huge amplification power and a result a strong and ugly compression. |
A lot of the stuff people believe about power makes an awful lot of sense. The only problem is that while the reasons make sense on paper they don't work out nearly so well in the real world. Point of order: one low-powered amp that sounds better than one high powered amp is by simple logic proof that power isn't everything. We have not one but hundreds of low powered amps that sound hugely better than thousands of much higher powered amps. So clearly something else is going on. What I think is going on, power is but one small item on a very long list of things that matter. In fact its kind of weak and pointless to qualify that. Its what I know is in fact going on. The list of things that affect sound is so much greater and longer than we know that it often strikes me as pointless to even be talking about them. I mean to talk about how many watts an amplifier puts out, in terms of sound quality, we might as well be talking about how many grains of sand in judging the beach at Cancun. Which would be a pretty nice beach... anywhere else but Cancun. |
This thread is worth a read (you can get the gist from the first two posts). By following the instructions you can work out how much power you need. If you look at the poll results you can see that >70% indicated 25W or less with nearly 40% needing only 4W. Power in itself is not a bad thing but assuming you are working to some kind of a budget then it would be best to find the highest quality amplifier that meets your needs within your budget. Power adds significantly to the production cost of a product (less so with class D) because some of the most expensive components within a power amp are the power supply and heatsinks the size of which are proportionately related to the rated output power. |
I dont still understand the arguments against LOL.... ALL OTHER THINGS BEING EQUAL (That is the part people seem to be missing) a higher power amplifier will always be preferable. It will run less stressed and have much more headroom. As for the higher distortion at lower levels of a power amp, even those higher levels of distortion is still well BELOW anyone's hearing so it is a moot point. |
Alexberger and atmasphere, I also agree that low efficiency means more power is needed and this results in thermal compression (as the wire in the voice coil heats up, resistance rises). That is why high efficiency speakers typically sound more dynamic and lively. The reason the industry moved away from high efficiency has a lot to do with the large size of typical high efficiency speakers. That size became an even "bigger" issue with the advent of stereo and the need for two speakers. Smaller speakers became a commercial necessity for stereo. |
