@@InsideOfMyOwnMind YES! I still play my 1979 Realistic STA-2100. I did rebuild my Optimus T-200's though. Sound great. Of course the thing only needs 5 watts to play loud.
Great discussion as always. I have a pair of 110w OTL triode monoblocs. You can run the same amp at 25w by pulling a couple triodes. It still has the same gain and everything in the system stays the same but the amp power. So perfect for understanding impact of lower watts. Into highly efficient speakers, the difference is the bass and overall authority thins out. With 110 watts, they are dynamic with full bass. Everything the same, at 25W the system still sounds great just lacks body and grunt. And the bass is underpowered. Even though I listen at
That’s what I was curious about, with the lower wattage (tube) amp in highly sensitive speakers will I be missing out on depth and bass. I’m auditioning an 7 W A-50 from boyuurange versus a 110 W solid-state amp by Exposure with 96 DB efficient speakers on the way. I’m pulling for the tube amp but I’m doubtful after reading your comment
@@taylorfusion I expect that the OTL design of W's monoblocs may affect the impact of removing a couple triodes. Since the A-50 has an output transformer, its bass may work better despite its low power.
@@sherrillshaffer579 Quite possible. The OTL circuit is by Transcendent Sound. Designer is convinced he sorted out the bass and it's driving an easy 8ohms, but who knows. Let us know which you like better. The SE 300B into efficient speakers may be quite special.
I remember when a local high end stereo store near me couldn't demonstrate a system without clipping problems. Of course the only amps they sold were Yamaha.
🤗 Great answer for beginners 👍 🤔 This was a great concern for me many years ago …not wanting to blow up my humble ,precious system 🤯😭 … but wanting to squeeze out every DB I could at that time 🤗😍😍😍
When setting up any amp for speakers I've found it's best to use a multimeter oscilloscope and a set of 0db test tones and a 0db sweeping test tone. This is a technique I've learned from doing car audio for years, and will give you max volume and clarity while preventing your speakers from blowing. 1) make sure speakers are disconnected then hook up the scope to your receiver. Play the desired test tones and find where the clipping point is and go a click or two below it. Some tones will clip before others use the tone that clips 1st to set you maximum volume level. Make a note of where that volume level is. 2)keep your speakers disconnected, then attach the scope to the amp outputs and play test tones to see where the amp clips. You want to keep the receiver at the max volume before it clips. Once you find the where the amp gain clips mark it. 3) turn the amp gains and receiver volume all the way down then turn off the system and attach the speakers or subwoofers. Then attach the scope to the speaker wires. 4) here comes the scary part... have test tones ready (40hz @ 0db for subwoofers and a sweeping tone @ 0db for full range speakers)play test tones at full volume before clipping on the receiver, keep the amp gain all the way down. While looking at the scope increase the amp gains until you the tones are at the desired wattage. You have to be quick playing test tones for too long at too loud a volume will damage speakers and subwoofers. You may also have to use ohms law and figure out the wattage this depends on your scope. Some scopes show wattage others will just show voltage. You can also find sweeping tones for subwoofers too if your worried about damaging the subwoofer. Also because of impedance changes at different frequencies a speaker will act differently with the same volume level. This may seem like a lot of stuff to do, but it can be done under an hour. Sound is always subjective and you may find yourself making adjustments after setting the gains, but this is a measured way to set gains and prevent clipping and distortion. Good luck & Great listening 🤗
Great point. I might add that smaller amplifiers may be a better match for high efficiency speakers because the noise floor is lower given equivalent dynamic range specs. Operating amplifiers at either end of their respective dynamic range also introduces higher levels of non linear response. In general, the best place to run an amplifier is in the middle of its dynamic envelope as long as it’s not too loud or to quiet.
I guess with "watts," I am also thinking about the current demand; maybe one of these days Paul can explain how current demand is where amplifiers really start to get into trouble on low impedance loads.
In my system my speakers are rated at 88db / 4 Ohm. My amp is rated at 500 Watts RMS output per channel into 4 Ohms, total harmonic distortion < 0.03 %. It is incredibly rare that I push out over 10 watts (as shown on my amp's meters) in normal listening situations.
I'm just excited the Jubilees are going on retail. With those, I could use triodes to alter my dynamic range and still be getting to live show volumes with as little as five watts for example. *edit: sorry, just realized I was plugging someone else. Still, can't argue with that.
some speakers especially some old ones from the 70's give louder sound db. instead of running 100w you can use 50w amplifier clips no different concert PA. speakers have higher sound by 50w than the newer hifi speakers provide at 50w
@Taco Wrong, obviously your heavy high power woofer is where most of the power goes especially with music having lots of bass in it. Subwoofers often max at 1000s of Watts while tweeters max at 10s of Watts for the same system. A drum typically emits more sound pressure energy than a voice, for example thus rock music needs more power than some vocal music. I enjoy music with deep bass playing reasonably loud and a small amp is not adequate. Of course this doesn’t mean Paul is wrong in the topic of efficiency.
@Taco Well, if you listen at low volumes with little sub bass, yes, you really don't need a lot of power. But if you listen fairly loud with a lot of sub bass shaking your house (like I do some times), you can peak on 100s of Watts in my setups easily (I measure these things). Sure, power is often over-rated and a doubling of power is barely noticeable (3dB). And this means you need incrementally more power to gain more loudness. E.g. it takes 900 Watts more to replace a 100 Watts amplifier to play twice as loud while it takes 9 Watts more to replace a 1 Watt amplifier to play twice as loud at peak. Yes, of course more efficient speakers need less power but efficiency can also come with a price of poor performance. For example, you can make bass more efficient by relying on bass ports and resonant designs but often with a price of poor decay performance and more distortion. I prefer closed chamber subwoofers with fast decay and low distortion; and they usually consume much more power.
@Taco That doesn't take into account modern systems with DSP correction. If you have a subwoofer that starts to roll off at 50Hz and you add a huge boost around 30Hz to level it out, you will definitely need a lot more power to drive that subwoofer.
I have Dali Opticon 2 MK2 speakers (4 ohms, 86.5 dB sensitivity, recommended amplifier power 50-150 watts) hooked up to a NAD C700 (100 watts into 4 ohms), and I'm worried I might have clipped it or damaged the tweeter when listening to Spotify at 77% volume. Is this possible?
hi Paul, is it more a question about the operating point in a class A, AB or D Amplifier ? if you have a sensitve Speaker Class A is your friend, with a lot of Power consumption. A sensitive Speaker with Class AB Amp you can run in a notlinear operating point with the Amplifier, the output is too low. Class D has no operating point it is on or off. I thnik the best is a good Class D amp, the best of two worlds
You're talking about changing to power supply voltages that are 3x higher than the circuitry is designed for. Don't even think about it! It would require a major redesign (not to mention much larger heat sinks), and it's far more practical to just buy a bigger amplifier. Then you can keep the 50w amplifier around for times that you don't want to play music loud, and you would like to save on your power bill.
I have a 90w amp playing into a pair of Ruark Crusaders - sensitivity 88db, impedance 6 Ohms. I hear what I assume is clipping on some classical recordings. Paul?
You could simple state that an efficient speaker only needs 10 watts to play really loud. Most amplifiers can produce 10 watts output without distortion. 😎
so I added a 60 watt power amp to my existing 60 watt integrated; I drive the tweeters with the integrated and mid_bass with the power amp. I do get more volume now but not by a crazy amount, but I do notice the sound being cleaner on the top end.
I think that means you are now getting more clean power to the speakers by keeping each amp further below the higher-distortion and clipping zones at a given sound level, or double (+3db) the volume for the same level of distortion.
Id stray away from using towers on a mainstream integrated receiver thats just me. Ive blown a tweeter or two that way : ( Some speakers will simply NOT move the woofers at all unless theres a high current amp driving em from my experience. A vintage Altec or Klipsch horn speaker should be fine on most anything however.
I drove a Klipsch La Scala with a smart phone as we unloaded it from the truck and carried it indoors. Just tossed the phone into the top cavity. You could hear it loudly across the street as this big "thing" with apparently nothing connected to it, blasting the neighborhood as we walked it to the door. It looked like something out of a British sitcom.
Even with a pair of speakers with 85 db in sensitivity you dont need that much power to play loud. I think its much worse with speakers dropping in impedence to about 3 Ohm and sometimes lower. Its very common with speakers dropping below 4 ohms. Even if they have high sensitivity mind has 90 db But drops to 3,1 Ohm in impdence They are quite difficult to drive. Many amps can have a lot of power in 8 ohms. But They rarely tell you how They perform with 4-2 ohms loads
Really isn't it all about keeping the voltage, on the output, from not hitting the rail voltage supply level? (That is, say the you have a split supply that is 18 volts plus and 18 volts minus, if you keep the output voltage below, say 15 volts on each side, 30 volts peak to peak, on it's maximum swing, you won't have clipping (So, no distortion.) ) As long as you stay a few volts below the rail supply voltages, you shouldn't have clipping, for class A or AB amps. For a class A amp, as long as the voltage, from the Q point on the load line (on the output device), doesn't swing into saturation or cutoff, there shouldn't be clipping, either. So, no distortion. Correctamundo?
Clipping happens when the amp is overstretched right? Speakers drawing too much power. Something that is not likely to happen at normal listening levels unless there is a massive mismatch between amp and speakers or the users are students in a dorm.
I think Paul should have emphasised your point, that the main danger comes from overdriving a small amp when using it with inefficient speakers whilst trying to achieve high sound levels. The musical sine wave is flattened at the top and bottom of each peak and trough in the voltage cycle, causing the speaker’s voice coils to overheat and burn out. A very short burst of this is relatively harmless, within reason, but a 1kW amp turned up through efficient speakers could just blow them up. Common sense should prevail. Your ears will tell you something’s wrong in either scenario. This is why decent speaker manufacturers such as Harbeth will guide you by quoting a minimum recommended amplifier power to use with each model.
Not that good an answer in my opinion ... the word headroom and dynamic range didn't get a mention ... along with peak power handling capacity of the speaker. A small low power amplifier bipolar or mosfet can burn out a higher power rated speaker if or when the amp clips ! Note this only applies to direct coupled output stages and not vacuum tube amps ...
@@mikeuk4130 the problem doesn't arise quite so much with transformer coupled tube amplifiers ... because they cannot couple DC . The problem with bipolar/ mosfet designs is that the speaker load has the ability to get driven into clipping on to the DC positive and negative supply rails .. Class D amplifiers don't have this problem .. or capacitor coupled Class A or AB transistor amplifiers.. such as the Quad 303
@@janinapalmer8368 Thanks for that, Janina. Presumably, the clipped i.e. flat parts of the wave are equivalent to DC whether + or - , or is that too simplistic?
The simple answer to the question is no. A 25watt amplifier operating with the volume control set halfway is no more likely to clip than a 100watt amplifier with its volume set halfway. The fact that the 100watt amp is louder has nothing to do with it.
As long as the output doesn't try to climb over the rails, no it doesn't. The part that _is_ concerning is audiophiles who do things like run dual 1.2kW monoblocks with bookshelf speakers. I don't think they have ever considered what would happen if there were a full power excursion. Even with speakers rated for that power I would not want to be anywhere near it. 140-150 dB with subs in a car is a lot different than 140-150 dB with full range speakers. Thats the main reason I don't run more power than I need. I never know when I will get all of it when I don't want it.
@Lassi Kinnunen 81 good points, those situations could occur...I do however always have more power on tap than necessary for any system I build, they just sound cleaner and more effortless.... peace
@@poserwanabe Easy. Listen to something like classical music that has its levels some 20-30 dB less than what you normally listen to, and forget to turn the volume down. Or just having the source go to 100% volume.
@@davidcontini7217 I enjoy my sports car, too, and drive north of 150 MPH despite said speed limit. But I don’t particularly enjoy listening at similar SPLs. The two are a false equivalence. I would easily use all 740 HP since cars don’t have absolute performance limits. Your hearing and ears do, so seldom do you use more that 100 watts of power. The other 2300 watts is just waiting to burn something out.
All good on paper and calculators but the ear hears what it likes and asks for more and with a fifty watt amp into 90db speakers your clipping amp is gonna break your heart.
The story with the voltage and gain is confusing me. If the voltage gain is the same for a 1000W amp as it is for a 10W amp that means that a 1000W amp would need a much higher input voltage to reach maximum power. It does not make sense with a normalized output voltage of pre-amplifiers.
