I feel so redeemed by the fact that someone as experienced as you is saying the same things I am saying. I experience a lot of resistance (pun intended) when trying to bring facts and science into audio discussion. I would love to hear how you feel about the mighty "watts rms" which I find to be a nonsensical unit in the context it's used.
Yes, I ear told me the same thing when class d amps came along, the old Bryston and Crest amps worked better. With class D I go for 50% more power to keep things safe.
Best explanation I have seen of Old tech (AB, H etc) Amps vs New Class D etc. Would be interested to see if there are any newer amps that can sustain the long bass tones e.g. LabGruppen PLM models. The old Crest 7001, 8001s would just keep pumping...
What would have been interesting to see is the recovery of the amp. I thought I saw a hint of it when you stopped the signal. This would give a good idea of how often you can hit it like that.
Power draw is a big deal for us. Power sag is an issue as well as feeder size and length and generator capacity. Also thermal issues if hot weather causes amps to shit down.
I wish amps would have ratings for the internal specs as energy storage/capacitance, rail voltage, and power supply wattage I assume would be better specs to pay attention to nowadays. I try to look at max power draw and efficiency numbers to get an idea of sustained output capacity even though that’s not the whole story for music.
What a great video series! I have just one consideration: when you divide Voltage^2 by R to compute the power you are supposing a purely resisitve load --> In case of a speaker, which is characterized by an impedance figure, it must be considered the frequency of the signal to compute the impedance. Nominal impedance is at 1 kHz. Lower frequencies (like the 225 Hz you had on the example) will lead to lower impedance since the inductance component will behave more more like a short circuit giving you the true resistive part and so, for the same voltage, higher currents (and power)
Hmmm, the resistive load of a typical speaker is closer to 1/2 the rated 8mpedance of most speakers. The rated impedance is an average of what to expect over the operating freq range The minimum impedance is typically no lower than 80% of the rated impedance but around resonance the actual impedance is much higher. Asking as the test methods are the same for various amps being compared we can get a good idea of what is happening. The peak power and the amount of time the amp can deliver that peak power is more important in audibly how loud an amp is. There is another factor where some amps capture and store back emf and increase their power as well.
@@DaveRat Yes, yes, I totally agree with You! I was just pointing out that in order to compute the power "given" by an amplifier by measuring the output voltage it's necessary to divide by the impedance at that frequency (on the Impedance vs Frequency chart) and not by the resistance or the nominal impedance of the speaker. The same would occur measuring Voltage and Current --> We need the phase between the two to compute the "actual" power and not just the Apparent one
@@DaveRat Hhahahaha thanks Dave for all you do. Had a great time hanging with ya at the sound forums meet up in Wachusett, Massachusetts! This was a while back, I think seven or eight years ago. We got to play around with some new Danley subs.
can you get hold of a VOID Acoustics Infinite 8 V2, and do the test with that??? i own such an amp and i think it's a great amp but, i kinda got doubtful about amps now... great videos thanks for each and everyone of them. you really reignited my passion for audio and tech again.
Wow, that was quite shocking, the rate at which the modern amp fell off surprised me, I have read about sagging but I hadn't imagined it would be that fast. Talk about cliff hanger, ... : )
Thanks for another great video Dave! I like the classic amps. For the most part today's products are BS compared to previous consumer goods from the 60s 70s and 80s. Too much engineered obsolescence now. Your tv's and automobiles forward all ambient sound to a 3rd party for possible future persecution. I drive cool old Fords and will never get rid of my fat stack of Adcom GFA 585's & 565's pushing those 15" and 18" Cerwin Vegas. Old school or no school!
I love vintage and also love tech. I don't forget that the vintage gear you live was high tech some day in the past. With someone saying, damn those new fangled cars, horse and buggies are the way to travel. I own a Tesla and I can honestly say it is superior in every way to any car I have ever driven I laugh at muscle cars trying to hedge me and not let me merge onto the freeway, "ha, you may be loud and smelly but at least you are slow! " I then proceed to silently pass the car in front of the car in front of them and make them tiny in my rear view mirror. And smile as I engage auto pilot. That is not to say I don't love vintage beautiful machines and cars and sound gear from all decades.
Aww Dave! How could you miss that?? P=IE ; as, Watts=Amps x Volts; then returning to Ohms law and derivations. I forgot all this twenty years ago until now!
@@DaveRat I used to rattle that off in my head for paltry u-ground circuits in refitted churches and impromtu art-galleries which couldn't anticipate the requirements. Always an adventure.
Waw... sorry Dave , Im not an expert , but with all respect due , you are talking about Efficiency for something called Sensitivity express in dB/1W/1m, efficiency is the ratio of the average acoustical power (in W) radiated by the loud- speaker to the total electrical average power (in W as well) supplied to the loudspeaker its a number without dimension or expressed in % wich is very different things ...
Keen to see where this leads. Does this explain the difference we hear between different classes of bass guitar amps? For example, my Gallien-Krueger 700RB-II feels noticeably more alive, responsive, punchy and with more character than similar output digital amps, including GK and Fender. I understand speakers/cab makes a difference but I have played enough different rigs to feel the difference. The tones can be similar and both are great options, but in my experience those MOSFET solid-state amps like the old GK 400/700/800 and old Trace Elliot AH250/AH300 amps simply delivered more of everything. You can push and push them much harder than their digital cousins. Curious to know your thoughts and understand the factors at play.
I'm curious what the spec sheet rating would be for the new amp that you just showed us. I was hoping to learn if the peak was the rating that manufacturers use as "peak" and if RMS was fairly true to being actually true RMS even during dynamic loading. If the modern amp you tested showed a rated 350 watts at 4 ohm RMS or something similar, then it would appear you only benefit from the peaks creating a large burst of power to follow dynamics of music instead of a more compressed, flat signal. I look forward to seeing where this goes
@@DaveRat I am only able to find one output rating for each impendence, which is, admittedly, laughably high. I would wager their "2000W @ 4 Ohm per channel" is a peak rating and therefore most likely 4x the actual RMS. Luckily, most brands in the price range I can afford list RMS, program, peak output power ratings
Not sure the vid this was posted about as it only shows the comment on my phone but maybe the info below applies and is helpful? RMS Power: When measuring a pure sine wave, RMS voltage can be calculated by measuring the peak voltage level and multiplying it by 0.707. This value can then be used to calculate RMS power. In turn, if the RMS power is known, it can be used to calculate the peak power.
OH! its the root of the average of the squares. In the video you said you wouldn't go into the math and I was trying my hand at the math. I wasn't considering the reality of the situation where we would have to take measurements to find the rms. Typical math nerd... Thank you!
Worth noting is that Ohm's Law is only for direct current. With alternating current you also have capacitive reactance and inductive reactance, and to calculate those successfully, you need some knowledge of vectors, phasors and imaginary numbers. Or you can cheat and eliminate all reactance (or close to it) from the circuit, leaving just the scalar resistance value that can work with Ohm's Law. As it turns out, testing with a purely resistive load also helps eliminate bias in testing by not favoring one kind of reactance over another, and not favoring one kind of load. In sound reinforcement, most loads will be inductive, so eliminating this bias is less critical than with hi-fi speakers, where one finds more capacitive reactance in drivers, and passive crossover elements. There's also test equipment that can hide all the calculus from you while testing real-world loads. But if you don't have access to fancy test equipment, you can still get accurate and precise measurements by using just a calibrated resistor, a good voltmeter and the DC power formula.
Great info and this is one of the reasons why I do a lot of perceptive testing and don't overly rely on numbers and data. Not only can the data be skewed by incomplete testing but also, without a way to relate data to what is actually audible and relevant, the data does not do us much good. How important is a watt? Hmmm, the first watt is extrodinarliy important but watt bumper 2999 out of 3000 is irrelevant. What does 1% thd sound like when listening at 90db vs 1% when listening at 115db? Does the distortion gave the same relevance at all listening levels? How come eq'ing to flat does not always sound good but there are systems eq'ed to flat that sound good? All wonderful stuff!
@@JohnnyGuitar1 no, it doesn't. As I said before, there's no way to deal with reactance. And just ignoring reactance doesn't work. Also, waveforms other than sine waves (like music) don't work with the square root of two as a cheat.
@@StringerNews1 Ohm’s Law works fine with alternate current. Omh’s Law is I=E/R and it does not require it to be DC. If you alternate the current (I), the law remains the same. I think what you mean is that Inductive reactance and Capacitive reactance are part of the total load. It still can be calculated with Xl and Xc simple formulas as such. However, to say that Ohm’s Law is only for DC, is completely incorrect.
@@JohnnyGuitar1 okay smartass, you use Ohm's Law to calculate the phasors for 33 µF in series with 1200 mH with a 1 MHz carrier frequency modulated to 50% by 1 kHz and 5 kHz. Go!
interesting video been trying to put together a small pa on battery running 50w a channel on 4 ohms with a 92db/1w speaker but curious if upgrading to a 99db/1w at 8 ohms would be worth the upgrade as it then gives 25w from the amp
A speaker that is 7 DB more efficient should be the same volume at less than 1/4 the power. That said speaker efficiencies need to be measured in the same range as you're using them and often manufacturers will use differing ways to measure efficiency. Oh for battery operated systems high efficiency speakers are the way to go
Yes the video math is correct. Speaker 1 94db 1 watts 104 10 watts 114 100 wats 124 1000 watts 127 2000 wats Speaker 2 100 1 watt 110 10 watts 120 100 watts 130 1000 watts Speaker 1 max is 127db at 2000 watts. Would need to handle 4000 watts to hit 130db that speaker 1 hits at 1000 watts.
@@DaveRat the 2000W text above the 4000W threw me off completely because it is a 6dB difference, not 3dB. I stand corrected. Thank you for being kind and helpful Dave.
@@DaveRat great! But would you like to be a real audio nerd’s hero? Most things you talk about in this video is already on CZcams on one form or another. But here is what is not so common: Why don’t manufactures make most drivers’ efficiency 101dB or above? What are the cons and pros of a higher efficiency above 101dB, besides the basic “heat” and price answer? What are the phase issues (related to Impedance) by becoming more efficient? These answers I am yet to find on CZcams.
@@DaveRat so in short for pro audio i should get the more efficient drivers? And what bout car audio subs that are so inneficient but can get so loud are they still the better option for car audio specifically or should a more efficient driver in car be louder IF the mechanical limits allow for it?
So this test is with the amps set just a hair below clipping, correct? How do the amplifiers behave when you have more headroom to work with, if the amps are running at, say 75% of their maximum capacity?
At lower outputs they are linear all good. On the member side i am doing a series of vids comparing the sound of various amps in overload as well as impacts of wall voltage coming soon
@@DaveRat So then I guess the best approach is to always try to get a slightly more powerful PA than you actually need so that you can run it with some headroom. As interesting as amplifier behaviour is when they're right on the edge, in practical terms a little headroom goes a long way.
@@NealMiskinMusic a lot of loudspeakers are killed from folks running amps at or under speaker rating, then running those amps into clipping. I was brought up to run 1.5 or 2x speaker rating for headroom and set limiters and listen to the speakers for any distortion they get from being ran too hard
I believe the calc is correct in the video. Speaker 1 94db 1 watts 104 10 watts 114 100 wats 124 1000 watts 127 2000 wats Speaker 2 100 1 watt 110 10 watts 120 100 watts 130 1000 watts Speaker 1 max is 127db at 2000 watts. Would need to handle 4000 watts to hit 130db that speaker 1 hits at 1000 watts.
@@DaveRat well in the video it seems you are talking about the 2kW speaker then telling 4 times the power, written under th 2k speaker, it should be 4x2=8k … I will re-watch it again
Ha! My guess is the every once in a while someone comes along bullying people or trying to propagate incorrect info. I try and resolve things cordially and with respect but sometimes it runs amuck and pretty sure these butt hurt knuckleheads hide in the shawdows like cowards and find joy in down thumbing. That said, what they don't know is that it makes me smile to think they spend their time thinking of me and that I have had such an impact on their life. Over the past 10 years or so I recall about 5 such humans, so overall, I think we are ok.
@@DaveRat Saw that on another video a few weeks ago from a different content creator. Some guy came into the chat dumping on everything that was said basically saying "you're wrong, I'm right". Not ashamed to admit, I bit and he soon departed the conversation with his tail between his legs... :D
I started doing the X4 on the member side of the channel with a video with my daughter Sammy and I won't be doing a K20 cuz I don't own one but I do have some other powersoft amps I'll look at
Are you referring to covering peak to peak by dividing by 2 and the multiplying times .707 to get RMS? If so, yes you can skip a step but not by multiplying 2x .707 The correct math is to multiply .707 x .5 to get .3535 Multiplying peak to peak by .3535 will give RMS voltage.
@@DaveRat I stand corrected Dave. This is rust from my electronics engineering course from 1983 plus not enough coffee, but I do live on stages with equipment, full time for a living. 0.3535 times ppV it is, of course, but still, you save an extra step.
Thank you so much Dave! There are likely a lot of “sound guys by need” like me out here that didn’t get this info in school. This helps a lot!
👍
Cheers Dave, i feel more validated for my sedimental purchase of an old Perreaux 9000B.
👍🔧🔧👍
I am so excited for this series in power amps!
👍
@@DaveRat czcams.com/video/tUxsP-792U4/video.html I booted up a pile of old crowns, after some heat ran through them they sort of booted up, ha ha
👍
I feel so redeemed by the fact that someone as experienced as you is saying the same things I am saying. I experience a lot of resistance (pun intended) when trying to bring facts and science into audio discussion.
I would love to hear how you feel about the mighty "watts rms" which I find to be a nonsensical unit in the context it's used.
Yes, I ear told me the same thing when class d amps came along, the old Bryston and Crest amps worked better. With class D I go for 50% more power to keep things safe.
👍👍👍
Thank you for that video. Can't wait for next episodes. All best.
Thank you Mario
The SQRT(2) = 0.7071 factor works for sine waves only. This would be 1.0 for square waves, and much less for a typical music signal.
True and thank you
Best explanation I have seen of Old tech (AB, H etc) Amps vs New Class D etc. Would be interested to see if there are any newer amps that can sustain the long bass tones e.g. LabGruppen PLM models. The old Crest 7001, 8001s would just keep pumping...
What would have been interesting to see is the recovery of the amp. I thought I saw a hint of it when you stopped the signal.
This would give a good idea of how often you can hit it like that.
👍
Fantastic as always
My subwoofer is very happy at the end of every video :)
It's cool to have a system that will play the end track!
I want to mention Georg Simon Ohm . Great guy.
Yes! Genius!
Great video man, but now days everyone goes for the K watt sticker, dont even bother to look at frequency respond or weight. and power draw.. 👍👍
Power draw is a big deal for us. Power sag is an issue as well as feeder size and length and generator capacity.
Also thermal issues if hot weather causes amps to shit down.
Grate video as always. I look forward to your videos. You produce content that I really like.
Thank you Yashvir!
Thanks Dave.
👍
I wish amps would have ratings for the internal specs as energy storage/capacitance, rail voltage, and power supply wattage I assume would be better specs to pay attention to nowadays. I try to look at max power draw and efficiency numbers to get an idea of sustained output capacity even though that’s not the whole story for music.
Agreed
What a great video series!
I have just one consideration: when you divide Voltage^2 by R to compute the power you are supposing a purely resisitve load --> In case of a speaker, which is characterized by an impedance figure, it must be considered the frequency of the signal to compute the impedance. Nominal impedance is at 1 kHz. Lower frequencies (like the 225 Hz you had on the example) will lead to lower impedance since the inductance component will behave more more like a short circuit giving you the true resistive part and so, for the same voltage, higher currents (and power)
Hmmm, the resistive load of a typical speaker is closer to 1/2 the rated 8mpedance of most speakers.
The rated impedance is an average of what to expect over the operating freq range
The minimum impedance is typically no lower than 80% of the rated impedance but around resonance the actual impedance is much higher.
Asking as the test methods are the same for various amps being compared we can get a good idea of what is happening.
The peak power and the amount of time the amp can deliver that peak power is more important in audibly how loud an amp is.
There is another factor where some amps capture and store back emf and increase their power as well.
@@DaveRat Yes, yes, I totally agree with You!
I was just pointing out that in order to compute the power "given" by an amplifier by measuring the output voltage it's necessary to divide by the impedance at that frequency (on the Impedance vs Frequency chart) and not by the resistance or the nominal impedance of the speaker.
The same would occur measuring Voltage and Current --> We need the phase between the two to compute the "actual" power and not just the Apparent one
Agreed.
If you don’t know who Dave Rat is, you should probably look him up…he’s been around for a bit!
Hell yes, will do, on it!
@@DaveRat Hhahahaha thanks Dave for all you do. Had a great time hanging with ya at the sound forums meet up in Wachusett, Massachusetts! This was a while back, I think seven or eight years ago. We got to play around with some new Danley subs.
can you get hold of a VOID Acoustics Infinite 8 V2, and do the test with that???
i own such an amp and i think it's a great amp but, i kinda got doubtful about amps now... great videos thanks for each and everyone of them. you really reignited my passion for audio and tech again.
Hmmm, who makes their amps? I don't think void makes amps so finding out the manufacturer would give more insight
Awesome video Dave; thanks!!
👍
Thanks dave...
Awesome and thank you! 👍
Wow, that was quite shocking, the rate at which the modern amp fell off surprised me, I have read about sagging but I hadn't imagined it would be that fast. Talk about cliff hanger, ... : )
And also it's important to note that not all new amps do that and it varies from model to model and manufacturer to manufacturer.
Thanks for another great video Dave! I like the classic amps. For the most part today's products are BS compared to previous consumer goods from the 60s 70s and 80s. Too much engineered obsolescence now. Your tv's and automobiles forward all ambient sound to a 3rd party for possible future persecution. I drive cool old Fords and will never get rid of my fat stack of Adcom GFA 585's & 565's pushing those 15" and 18" Cerwin Vegas. Old school or no school!
I love vintage and also love tech. I don't forget that the vintage gear you live was high tech some day in the past. With someone saying, damn those new fangled cars, horse and buggies are the way to travel.
I own a Tesla and I can honestly say it is superior in every way to any car I have ever driven
I laugh at muscle cars trying to hedge me and not let me merge onto the freeway, "ha, you may be loud and smelly but at least you are slow! "
I then proceed to silently pass the car in front of the car in front of them and make them tiny in my rear view mirror. And smile as I engage auto pilot.
That is not to say I don't love vintage beautiful machines and cars and sound gear from all decades.
Aww Dave! How could you miss that?? P=IE ; as, Watts=Amps x Volts; then returning to Ohms law and derivations. I forgot all this twenty years ago until now!
I know I missed lots of things!
I quit college instead of hurting the dean.
Good stuff
@@DaveRat I used to rattle that off in my head for paltry u-ground circuits in refitted churches and impromtu art-galleries which couldn't anticipate the requirements. Always an adventure.
👍
Waw... sorry Dave , Im not an expert , but with all respect due , you are talking about Efficiency for something called Sensitivity express in dB/1W/1m, efficiency is the ratio of the average acoustical power (in W) radiated by the loud- speaker to the total electrical average power (in W as well) supplied to the loudspeaker its a number without dimension or expressed in % wich is very different things ...
Yes, this is true
My guess is that 90% of music actually has a "loudness signature" simular to the power handling capabilyties of new amps.
They do try and design the higher end new amps to match that signature and cheaper amps design for a spec rating.
Keen to see where this leads. Does this explain the difference we hear between different classes of bass guitar amps? For example, my Gallien-Krueger 700RB-II feels noticeably more alive, responsive, punchy and with more character than similar output digital amps, including GK and Fender. I understand speakers/cab makes a difference but I have played enough different rigs to feel the difference. The tones can be similar and both are great options, but in my experience those MOSFET solid-state amps like the old GK 400/700/800 and old Trace Elliot AH250/AH300 amps simply delivered more of everything. You can push and push them much harder than their digital cousins. Curious to know your thoughts and understand the factors at play.
Hmmm, I am remiss to jump to conclusions about related gear without testing
I'm curious what the spec sheet rating would be for the new amp that you just showed us. I was hoping to learn if the peak was the rating that manufacturers use as "peak" and if RMS was fairly true to being actually true RMS even during dynamic loading. If the modern amp you tested showed a rated 350 watts at 4 ohm RMS or something similar, then it would appear you only benefit from the peaks creating a large burst of power to follow dynamics of music instead of a more compressed, flat signal.
I look forward to seeing where this goes
You can see the specs, look up a powersoft T904
@@DaveRat I am only able to find one output rating for each impendence, which is, admittedly, laughably high. I would wager their "2000W @ 4 Ohm per channel" is a peak rating and therefore most likely 4x the actual RMS. Luckily, most brands in the price range I can afford list RMS, program, peak output power ratings
Download the actual owners manual and I believe it will clarify the spec
👍
👍🤙👍
Hi Dave how is your experience with Hypex based class d amps
Hmmm, never used or looked into them
I've tried learning how to calculate my power amps so I have perfect match power going to my cabinets but Bro this is over my head haaaaa
👍🔧👍
the average val of the absolute value of the sine function is .637 not .707, I'm a little confused on where that number is coming from
Not sure the vid this was posted about as it only shows the comment on my phone but maybe the info below applies and is helpful?
RMS Power:
When measuring a pure sine wave, RMS voltage can be calculated by measuring the peak voltage level and multiplying it by 0.707. This value can then be used to calculate RMS power. In turn, if the RMS power is known, it can be used to calculate the peak power.
OH! its the root of the average of the squares. In the video you said you wouldn't go into the math and I was trying my hand at the math. I wasn't considering the reality of the situation where we would have to take measurements to find the rms. Typical math nerd... Thank you!
Cool cool!
Worth noting is that Ohm's Law is only for direct current. With alternating current you also have capacitive reactance and inductive reactance, and to calculate those successfully, you need some knowledge of vectors, phasors and imaginary numbers. Or you can cheat and eliminate all reactance (or close to it) from the circuit, leaving just the scalar resistance value that can work with Ohm's Law. As it turns out, testing with a purely resistive load also helps eliminate bias in testing by not favoring one kind of reactance over another, and not favoring one kind of load. In sound reinforcement, most loads will be inductive, so eliminating this bias is less critical than with hi-fi speakers, where one finds more capacitive reactance in drivers, and passive crossover elements. There's also test equipment that can hide all the calculus from you while testing real-world loads. But if you don't have access to fancy test equipment, you can still get accurate and precise measurements by using just a calibrated resistor, a good voltmeter and the DC power formula.
Great info and this is one of the reasons why I do a lot of perceptive testing and don't overly rely on numbers and data.
Not only can the data be skewed by incomplete testing but also, without a way to relate data to what is actually audible and relevant, the data does not do us much good.
How important is a watt?
Hmmm, the first watt is extrodinarliy important but watt bumper 2999 out of 3000 is irrelevant.
What does 1% thd sound like when listening at 90db vs 1% when listening at 115db?
Does the distortion gave the same relevance at all listening levels?
How come eq'ing to flat does not always sound good but there are systems eq'ed to flat that sound good?
All wonderful stuff!
“….Ohm’s Law is only for direct current” - Ohm’s Law works perfectly well with Alternate current too, not just direct current.
@@JohnnyGuitar1 no, it doesn't. As I said before, there's no way to deal with reactance. And just ignoring reactance doesn't work. Also, waveforms other than sine waves (like music) don't work with the square root of two as a cheat.
@@StringerNews1 Ohm’s Law works fine with alternate current. Omh’s Law is I=E/R and it does not require it to be DC.
If you alternate the current (I), the law remains the same.
I think what you mean is that Inductive reactance and Capacitive reactance are part of the total load.
It still can be calculated with Xl and Xc simple formulas as such.
However, to say that Ohm’s Law is only for DC, is completely incorrect.
@@JohnnyGuitar1 okay smartass, you use Ohm's Law to calculate the phasors for 33 µF in series with 1200 mH with a 1 MHz carrier frequency modulated to 50% by 1 kHz and 5 kHz. Go!
What if some amps use 30a/220 and break it down to a lower v does it still reduce the performance of the amp. Or 30a twist plug to a 110
Would need to test but I believe most amps put out rated power with rated input ac. And with lower supply the output derated
interesting video been trying to put together a small pa on battery running 50w a channel on 4 ohms with a 92db/1w speaker but curious if upgrading to a 99db/1w at 8 ohms would be worth the upgrade as it then gives 25w from the amp
A speaker that is 7 DB more efficient should be the same volume at less than 1/4 the power. That said speaker efficiencies need to be measured in the same range as you're using them and often manufacturers will use differing ways to measure efficiency. Oh for battery operated systems high efficiency speakers are the way to go
Dave at 11:30 you say that it needs 4000W to get as loud, yet it is a 6dB difference, so it should be 8000W.
Am I missing something?
Yes the video math is correct.
Speaker 1
94db 1 watts
104 10 watts
114 100 wats
124 1000 watts
127 2000 wats
Speaker 2
100 1 watt
110 10 watts
120 100 watts
130 1000 watts
Speaker 1 max is 127db at 2000 watts. Would need to handle 4000 watts to hit 130db that speaker 1 hits at 1000 watts.
@@DaveRat the 2000W text above the 4000W threw me off completely because it is a 6dB difference, not 3dB.
I stand corrected.
Thank you for being kind and helpful Dave.
👍 cool cool! I appreciate the double check! Keep me on my toes, all good!
@@DaveRat great! But would you like to be a real audio nerd’s hero?
Most things you talk about in this video is already on CZcams on one form or another.
But here is what is not so common:
Why don’t manufactures make most drivers’ efficiency 101dB or above?
What are the cons and pros of a higher efficiency above 101dB, besides the basic “heat” and price answer?
What are the phase issues (related to Impedance) by becoming more efficient?
These answers I am yet to find on CZcams.
@@DaveRat so in short for pro audio i should get the more efficient drivers? And what bout car audio subs that are so inneficient but can get so loud are they still the better option for car audio specifically or should a more efficient driver in car be louder IF the mechanical limits allow for it?
So this test is with the amps set just a hair below clipping, correct? How do the amplifiers behave when you have more headroom to work with, if the amps are running at, say 75% of their maximum capacity?
At lower outputs they are linear all good. On the member side i am doing a series of vids comparing the sound of various amps in overload as well as impacts of wall voltage coming soon
@@DaveRat So then I guess the best approach is to always try to get a slightly more powerful PA than you actually need so that you can run it with some headroom. As interesting as amplifier behaviour is when they're right on the edge, in practical terms a little headroom goes a long way.
And using limiters that allow you to hit the system hard when needed without bad sounds
@@NealMiskinMusic a lot of loudspeakers are killed from folks running amps at or under speaker rating, then running those amps into clipping. I was brought up to run 1.5 or 2x speaker rating for headroom and set limiters and listen to the speakers for any distortion they get from being ran too hard
👍
11:32 4 times more power out 2kW = 8kW not 4kW ... or did I missed something?
I believe the calc is correct in the video.
Speaker 1
94db 1 watts
104 10 watts
114 100 wats
124 1000 watts
127 2000 wats
Speaker 2
100 1 watt
110 10 watts
120 100 watts
130 1000 watts
Speaker 1 max is 127db at 2000 watts. Would need to handle 4000 watts to hit 130db that speaker 1 hits at 1000 watts.
@@DaveRat well in the video it seems you are talking about the 2kW speaker then telling 4 times the power, written under th 2k speaker, it should be 4x2=8k … I will re-watch it again
So where is the error in the db to watts conersions shown in the post above?
@@DaveRat no no I never told an error in dB calculation. Just having umder the eyes 2000W, sayong 4times thata value, it’8000w. Not 4000.
Ahh, I could see the confusion with the text, should have made it more clear. I think what I say in the vid should be correct
thumbs down? really? congrats to "that guy"
Ha! My guess is the every once in a while someone comes along bullying people or trying to propagate incorrect info. I try and resolve things cordially and with respect but sometimes it runs amuck and pretty sure these butt hurt knuckleheads hide in the shawdows like cowards and find joy in down thumbing.
That said, what they don't know is that it makes me smile to think they spend their time thinking of me and that I have had such an impact on their life.
Over the past 10 years or so I recall about 5 such humans, so overall, I think we are ok.
@@DaveRat Saw that on another video a few weeks ago from a different content creator. Some guy came into the chat dumping on everything that was said basically saying "you're wrong, I'm right". Not ashamed to admit, I bit and he soon departed the conversation with his tail between his legs... :D
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Was this made with my comment in mind?
Probably a factor as I got several comments guiding me in this direction
@@DaveRat Still waiting for X4 vs K20 :D
I started doing the X4 on the member side of the channel with a video with my daughter Sammy and I won't be doing a K20 cuz I don't own one but I do have some other powersoft amps I'll look at
"Old" tube amp at full power/overdrive may sound "awesome", the "new" digital amp may not ;-)
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so basically I sold all my passive speakers because I couldn't afford the amps I needed. I should just quit all together
well, either that or rock on and bump it up a notch
Dave you can just skip an extra step by multiplying Peak to Peak times 1.14.
Are you referring to covering peak to peak by dividing by 2 and the multiplying times .707 to get RMS?
If so, yes you can skip a step but not by multiplying 2x .707
The correct math is to multiply
.707 x .5 to get .3535
Multiplying peak to peak by .3535 will give RMS voltage.
@@DaveRat I stand corrected Dave. This is rust from my electronics engineering course from 1983 plus not enough coffee, but I do live on stages with equipment, full time for a living.
0.3535 times ppV it is, of course, but still, you save an extra step.
Yes, agreed and in future vids I switched.