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How Many AMPS do My speakers need for full resolution maximum detail ?

Earwax

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For 8-ohm speakers with a 140-watt continuous power rating, Do l need an amplifier that can deliver at least 140 watts, but ideally 280 watts (1.5-2 times the speaker rating) to handle power spikes and ensure a healthy margin ?

  • Matching Impedance:
    Is it crucial the amplifier's output impedance match the speaker's impedance (8 ohms in this case) ?

  • Power Rating:
    Does the amplifier's power rating need to at least be equal to, but ideally greater than, the speaker's continuous power rating ?

  • Power Spikes:
    Speakers can experience sudden power spikes during music playback, so is it's a good idea to choose an amplifier with a bit of headroom ?

  • Rule of Thumb:
    Is it a common rule of thumb to choose an amplifier that can deliver 1.5 to 2 times the speaker's continuous power rating ?

  • Example:
    Is it any detailed improvement if your speakers have a 140-watt continuous power rating to have an amplifier rated for 280 watts (2 x 140) instead of 50 watts per channel for medium volume level ?

    I`m aware that higher current adds more precise control so question is at what current rating ( Watts divided by Volts = Amps ) is the optimum for a medium volume level ?

    My Harman Kardon AVR 140 is only putting out 50 watts per channel in stereo mode, probably good I`ve always lived in Apt or suites and have never turned them up to their full potential ? AVR 140 is also Rated 25 amps if that matters...

  • Speaker Spec`s here :

On The Bench :
 
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What does "full potential" mean? You've always been happy with the output with the HK avr? Why worry?
 
What does "full potential" mean? You've always been happy with the output with the HK avr? Why worry?
Since I bought the SMSL SU1 and Fosi DS1 Yes I`m enjoying them.

Mostly just curious, I`m very happy with my setup only interested in learning more and understanding the actual noticeable improvement if I was to use Fosi V3 mono blocks to get more detail out of the speakers ?

I`m not exactly anywhere close currently to understanding where that amp curve stops having an impact on the detail of the full dynamic range.

Any guidance is appreciated I`m a bit stubborn sometimes so getting to the root is only a matter of time but time is precious :)
 
Since I bought the SMSL SU1 and Fosi DS1 Yes I`m enjoying them.

Mostly just curious, I`m very happy with my setup only interested in learning more and understanding the actual noticeable improvement if I was to use Fosi V3 mono blocks to get more detail out of the speakers ?

I`m not exactly anywhere close currently to understanding where that amp curve stops having an impact on the detail of the full dynamic range.

Any guidance is appreciated I`m a bit stubborn sometimes so getting to the root is only a matter of time but time is precious :)
Just sounds like you should keep enjoying using your system rather than worry about the bullshit....
 
If you have access to another power amp, use the preamp output on the AVR to the input on the external amp. Find a buddy with a 2, 3, or 5 channel
power amp, RCA inputs and see for yourself if you want or need the extra headroom (or power)

You are looking for an amp or amps with at least 2 channels (or a pair of monoblocks) with at least 75-200 WATTS (not amps) or more per channel
at 8 ohms.

So you will need 2 channels of power or a stereo power amp. ONE power amp per speaker
RCAs to go from the AVR preamp output to the power amp inputs
An appropriate power cord/cable
Hook the speaker cable from the external power amp to the main right and left speakers.

TRY IT if you can borrow a power amp.

Unless you're driving the internal amps into clipping turn it up and find out from the existing internal power amps.

40 watts at 8ohms per channel is nothing to sneeze at. If the speakers are rated at 140 watts of continuous power (NOT AMPS, WATTS) they can handle three times the wattage you're currently driving them with.

I listen at 5-20 watts per channel. I don't use AVRs but I do have a few. If I am messing around with more than 2 channel (stereo) sound I use an AVP and usually around
200-500 WATTS (not amps) per channel. I use a Krell HT51 or Mcintosh MX120/121/122. Depends on what's out of the box at the time or easiest to get to.

I use Nord NC500oem One Up (monoblocks) and I have a 3-channel Nord that is the same except all 3 channels are in the same chassis. All 3 have separate power supplies.

Now is everything as clear as mud? :-)

WATTS not AMPS and borrow an external amp if you can. If you were close I'd let you borrow an older Adcom 7500 @ 125/8 ohms per channel. I used it for years
to test different stuff. I'm sure I have a pallet of retired Adcoms here. I gave up on HT close to 15 years ago. I don't watch TV except for the occasional
concert from time to time and we have company over that would like to see/hear something live.

Have fun and don't get the neighbors too pissed off or better yet invite them over.

Regards
 
Here is what Google Ai has to say about my question for general reference and a laugh ?
 
Sorry about that I`ve Edited my post now it is more suited to my specific inquires, I see where you guys are coming from with that now :)
 
If you have access to another power amp, use the preamp output on the AVR to the input on the external amp. Find a buddy with a 2, 3, or 5 channel
power amp, RCA inputs and see for yourself if you want or need the extra headroom (or power)

You are looking for an amp or amps with at least 2 channels (or a pair of monoblocks) with at least 75-200 WATTS (not amps) or more per channel
at 8 ohms.

So you will need 2 channels of power or a stereo power amp. ONE power amp per speaker
RCAs to go from the AVR preamp output to the power amp inputs
An appropriate power cord/cable
Hook the speaker cable from the external power amp to the main right and left speakers.

TRY IT if you can borrow a power amp.

Unless you're driving the internal amps into clipping turn it up and find out from the existing internal power amps.

40 watts at 8ohms per channel is nothing to sneeze at. If the speakers are rated at 140 watts of continuous power (NOT AMPS, WATTS) they can handle three times the wattage you're currently driving them with.

I listen at 5-20 watts per channel. I don't use AVRs but I do have a few. If I am messing around with more than 2 channel (stereo) sound I use an AVP and usually around
200-500 WATTS (not amps) per channel. I use a Krell HT51 or Mcintosh MX120/121/122. Depends on what's out of the box at the time or easiest to get to.

I use Nord NC500oem One Up (monoblocks) and I have a 3-channel Nord that is the same except all 3 channels are in the same chassis. All 3 have separate power supplies.

Now is everything as clear as mud? :)

WATTS not AMPS and borrow an external amp if you can. If you were close I'd let you borrow an older Adcom 7500 @ 125/8 ohms per channel. I used it for years
to test different stuff. I'm sure I have a pallet of retired Adcoms here. I gave up on HT close to 15 years ago. I don't watch TV except for the occasional
concert from time to time and we have company over that would like to see/hear something live.

Have fun and don't get the neighbors too pissed off or better yet invite them over.

Regards
I`ve edited my initial post to clear things up Watts divided by Volts = Amps. That said the flow of electrons is measured using amps One ampere is 6.24 BILLION electrons per second passing through a circuit.
 
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JBL's brochure says their recommended amp power allows for peaks. They're also rated for 90db/w.

So I wouldn't go much higher than that, if any.

All that said, if you've never turned your amp up all the way and you've never noticed a lack of power, you don't need new amps. The speakers matter more for SPL and 90dB is on the high end. 1 watt gets you close to damaging your hearing already.

An upgraded amp will sound the same as this one.
 
Is it correct to assume my Harman Kardon AVR 140 is using a 20 volt signal to my front speakers ?

It`s nowhere in the manual or online, Is there a standard voltage used for a specific watt rating as implied from my online inquires stated below.

Voltage = √(50 watts * 8 ohms) = √(400) = 20 volts RMS
 
Is it correct to assume my Harman Kardon AVR 140 is using a 20 volt signal to my front speakers ?

It`s nowhere in the manual or online, Is there a standard voltage used for a specific watt rating as implied from my online inquires stated below.

Voltage = √(50 watts * 8 ohms) = √(400) = 20 volts RMS
What actually drives the speaker is the voltage, so I think you're right that the maximum voltage is probably 20 at 8 ohms.
 
JBL's brochure says their recommended amp power allows for peaks. They're also rated for 90db/w.

So I wouldn't go much higher than that, if any.

All that said, if you've never turned your amp up all the way and you've never noticed a lack of power, you don't need new amps. The speakers matter more for SPL and 90dB is on the high end. 1 watt gets you close to damaging your hearing already.

An upgraded amp will sound the same as this one.
Thank you for the reply it is very much appreciated.

I am happy with my setup, honestly just inquiring for further knowledge for myself and friend's who have been taken advantage of like myself 25 years ago buying my 1st amp so know I want to know the details.

The Harman Kardon AVR 140 is my 3rd amp and I honestly lucked out having the pure direct mode, and it complimenting the JBL speakers...
 
An upgraded amp will sound the same as this one.
It's not a question that it may sound the same at 10-30 watts it's the difference when it's turned up and actually uses 100-200 watts which mainly will be
consumed by sub/bass drivers 300hz and below. There may not be much higher spl but the frequency response and where the watts are consumed
makes all the difference in the world if you can supply the difference to drivers other than a tweeter. Yes, No!

What does a tweeter take to drive full tilt 5-20 watts max? The bass drivers can easily consume 200watt peaks per cabinet vs 40 watts PEAKS total from the amps

The difference then 6.99db but mainly sub/bass and maybe mids, I'd have to see how the speaker is set up.

The difference would be quite noticeable and your neighbors would tell you all about it, I'm sure.

The right amount of power to the a speaker is pretty important especially when you get into larger sub/bass drivers. It changes the was the speaker sounds
if you room is set up to take 90+ db. Most aren't and DSP sucks the power trying to keep measurement close unless the room is treated for at least 300hz >

Below 300hz is pretty easy to fix these days with DBA, placement and DSP (I can't stand using it) It just sucks the life out of a great song when room treatment
makes the neighbors a lot happier and you too. Sub/bass is always a concern with neighbors though, unless you're trying to piss them off. Depends on who it
is right.

Borrow an amp see for yourself and don't blow the speaker up, Ay! Besides you got something better to do.?

Regards
 
For 8-ohm speakers with a 140-watt continuous power rating, Do l need an amplifier that can deliver at least 140 watts, but ideally 280 watts (1.5-2 times the speaker rating) to handle power spikes and ensure a healthy margin ?

Crude Graph:

Volts, Amperes, Watts, and SPL for a 90dB sensitive 8 ohm speaker:

Very loud - 100dB requires only 3~4 watts or so

Very very loud requires much more power.

Adding 3dB SPL (not a big step) doubles the power. Not a factor at lower SPL, but gets crazy quickly with more loudness.

1743441393943.png
 
Power can be calculated as:
Power (watts) = Voltage x Current (the "basic formula").

Ohm's Law describes the relationship between current = Voltage/ Resistance (resistance and impedance is "the resistance to current flow".)

From those you can derive:
Power = Current Squared x Resistance
and Power = Voltage Squared / Resistance. (This formula is often handy because it's easier to measure, or know, voltage than current.)

So according to my handy-dandy spreadsheet, 140W into 8-Ohms is about 4.2 Amps (and about 33.5V).

Matching Impedance:
Is it crucial the amplifier's output impedance match the speaker's impedance (8 ohms in this case) ?
Wrong! ;) The amplifier has a rated minimum load impedance. i.e. An amplifier rated for 4 Ohms can be used with 8-Ohms speakers but an amplifier rated for 8-Ohms can't be safely used with 4-Ohm speakers. Amplifiers are "voltage sources" which means they will put-out the same voltage at 4 Ohms, 8-Ohms or with no speaker connected (infinite impedance). If the amp isn't rated for 4-Ohms, you'll "pull" excess current, the voltage may drop and "bad things" can happen.

The amplifier's actual output impedance is usually a fraction of an Ohm. You won't find a spec for it but sometimes you'll see a spec for damping factor which is the ratio of load impedance to the amplifier's output impedance.

Power Rating:
Does the amplifier's power rating need to at least be equal to, but ideally greater than, the speaker's continuous power rating ?

Power Spikes:
Speakers can experience sudden power spikes during music playback, so is it's a good idea to choose an amplifier with a bit of headroom ?

Rule of Thumb:
Is it a common rule of thumb to choose an amplifier that can deliver 1.5 to 2 times the speaker's continuous power rating ?
No. 140W Speakers are designed to be safe with a 140W amplifier that's hitting 140W on the program peaks (with a much lower average power level). It's "statistical" and approximate because it's the short-term average power that burns-up speakers and the peak-to-average depends on the program's (unknown and variable) dynamics.

You can burn-out a speaker with full-power constant test tones, especially the tweeter which can't take as much power as the woofer.
You can burn-out a speaker using an amplifier with more power than the speaker's rating (if you actually "use" the available power).
You can burn-out a speaker by pushing an amplifier with a "matched" rating into clipping/distortion. When it's clipping, the peaks are limited but the average power continues to go-up as you turn-up the volume and the clipping generates harmonics some of which go to the tweeter. *

Example:
Is it any detailed improvement if your speakers have a 140-watt continuous power rating to have an amplifier rated for 280 watts (2 x 140) instead of 50 watts per channel for medium volume level ?
You don't gain anything from headroom unless you use the extra power. And if you're using it, it's no longer headroom! ;)

I`m aware that higher current adds more precise control
Nonsense. A higher damping factor can give you more "control" but with solid state amplifiers it's not an issue. Some tube amps have a poor damping factor.

My Harman Kardon AVR 140 is only putting out 50 watts per channel in stereo mode, probably good I`ve always lived in Apt or suites and have never turned them up to their full potential ?
As above, extra-unused headroom gives you nothing.

AVR 140 is also Rated 25 amps if that matters...
That would be 5000 Watts! Kind-of a meaningless spec... SOME "extra current" capability CAN be helpful because speaker impedance isn't "flat" across the frequency range. It's not unusual for the impedance of an "8-Ohm" to drop to 4 or 6-Ohms at certain frequencies, and since the lower impedance will try to "pull" more current, if the amp can't supply the current, the voltage will drop and the amp will clip.



* There is a popular myth that a higher power amp is safer than a lower-power clipped amp. Both are "dangerous" and the higher-power amp is worse.

P.S.
for full resolution maximum detail ?
Resolution mostly relates to digital. I suppose noise (hum, hiss, or whine in the background) reduces analog resolution but we usually just talk about noise. BTW - If you listen to an 8-bit file the loss of resolution is heard as "quantization noise".

Detail isn't really defined either. It makes me think if high frequencies... Boosted highs = more detail, rolled-off highs = less detail... BUT surprising to me, Dan Clark (headphone manufacturer) says certain distortion is often described as "more detailed".
 
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Doug, Thank you for your time !

You cleared up so much for me, and knowing I was wrong about adding more amps is very educational !!!

The main reason I bought the Harman Kardon was due to the 25 amp rating as the other 2 mainstream amps I had were very low current rating and just crap quality sound, the HK left them inhaling much dust...

Also shout out to all who have replied thank you for your time, but it looks like Doug hit it out of the ball park.
 
My full speaker 5.1 set is all JBL North ridge series,

Fronts : N28 150W
Centre : N Centre 150W
Rear`s : N24 100W
Sub : PB10 150W

So with the 5.1 setup in mind I guess my amp is over powered by about 10 amps.

I never have volume anywhere close to full for movies so none of that is needed.

Moving forward I`ll research on Dampening in Amps, thanks again.
 
Now this looks like a great time to ask about speaker wire Gauge, I`m unsure if it`s 20 or 24 AWG running from amp to my front and center, for the rear accent speakers it`s ether 22 or 24 AWG.


10 foot length for fronts

Centre is about 5 foot

Rear are 30 and 20 foot length.

Is it the small gauge speaker wire giving much less resistance that gives the rich clear sound or am misunderstanding the whole prosses ? and fooling my ears with my brain ?

I was using the much larger 12 gauge wire ( suggested by sales rep ) in my fronts then swapped to the 18 gauge that I was using for all speakers with little change.

It sounded like much improvement using smaller 22 ish gauge wires wire..

All were and are pure copper.
 
The longer the run the larger the gauge. None of yours look to be that long other than 22awg for 20 to 30 feet I wouldn't do. There's some tables and guides scattered about the site this is one of them.


Myself, I'd just buy a roll of 12 or 14 awg and use for all of them.
 
WATTS, not Amps. Watts is the result of Amps X Volts. It is the measurement of work that WAS achieved.

BTW You said IF the main speakers were rated at 140 watts of continuous power, that is not peak or over short periods of time that is continuous.
Speakers depending on the manufacturer can be say 140 watts of continuous power it doesn't mean they are correct, although some speaker companies
are VERY conservative.

If your amps are rated @ 50/40 watts RMS that inference implies it is continuous. 50 to the mains and 40 to the surround and center.

The problem with not enough power is if the amps clip, where if they are overpowered you turn it down and BOTH will blow a speaker. fuses or both.

Normally most amps have some sort of heat protection. Thermal shutdown vs inrush peaks that usually blow FB fuses vs overheating and shutting down.

That HK likely has protection, check the manual and see if it has both. Both are for amp protection Some amps actually have speaker protection
and it is not in every amp by any means. Adcoms GFA 565s were notorious sub/bass speaker killers.

As for speaker wire size use copper and 12-14-16 gage or double the run if your going to run 24/22 gage. That is pretty small and you're not saving anything
if you just use good zip cord from PE, Ali, Amazon at 30-50.00 for 250-500 ft. Do NOT use aluminum or aluminum clad cabling anywhere in your system.
Your asking for trouble.
 
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