Hi!
I consider myself as a newbie, although I've been making DIY amps for some time. Last night, I started thinking about voltage vs ampere at the output (to the speaker) on the amplifier.
As I've understood it; the voltage will push the cone out or in, and the ampere is how much power or force it have. That means you'll get much more "punchy" and quick bass with more amps.
I've seen some huge chipamps at ebay, capable of delivering ~500w at 8ohm. they have a maximum operating voltage of +- 40v, but will deliver huge amounts of current to the speaker. What if you have an 18" long stroke subwoofer. wouldn't +- 40v be way too small for such speaker? I know that the current is the thing that "really" matter, but you can't max out you speaker if the voltage is too low?
Is it "better" (on large speakers) to have +-36v with a peek of 10A to the speaker, or +-60v and a peek of 6A?
I consider myself as a newbie, although I've been making DIY amps for some time. Last night, I started thinking about voltage vs ampere at the output (to the speaker) on the amplifier.
As I've understood it; the voltage will push the cone out or in, and the ampere is how much power or force it have. That means you'll get much more "punchy" and quick bass with more amps.
I've seen some huge chipamps at ebay, capable of delivering ~500w at 8ohm. they have a maximum operating voltage of +- 40v, but will deliver huge amounts of current to the speaker. What if you have an 18" long stroke subwoofer. wouldn't +- 40v be way too small for such speaker? I know that the current is the thing that "really" matter, but you can't max out you speaker if the voltage is too low?
Is it "better" (on large speakers) to have +-36v with a peek of 10A to the speaker, or +-60v and a peek of 6A?
It is the speaker impedance and power that you use to work out what amplifier you need.
Amplifiers usually come in watts and into a certain impedance(s).
i.e. 500 watts RMS into 4 ohms.
So for this you can use 2 off 250WRMS speakers that are 8 ohms in parallel.
There is the age old and controversial question about amplifier power and speaker power.
Personally I prefer to make the speakers much more powerful so they are harder to destroy with big volume from the amplifier.
Amplifiers usually come in watts and into a certain impedance(s).
i.e. 500 watts RMS into 4 ohms.
So for this you can use 2 off 250WRMS speakers that are 8 ohms in parallel.
There is the age old and controversial question about amplifier power and speaker power.
Personally I prefer to make the speakers much more powerful so they are harder to destroy with big volume from the amplifier.
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Hi,
Understand resistance R = V/I, V = IR and I = V/R.
Power is VxI = I^2R = V^2/R = watts.
60V and 6A implies a load of of 10R.
36V and 10A implies a load of 3.6R.
The power is the same but the latter in reality is
far more practical with real speakers impedances.
rgds, sreten.
Understand resistance R = V/I, V = IR and I = V/R.
Power is VxI = I^2R = V^2/R = watts.
60V and 6A implies a load of of 10R.
36V and 10A implies a load of 3.6R.
The power is the same but the latter in reality is
far more practical with real speakers impedances.
rgds, sreten.
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Hi
I see a couple of very different threads to the original post.
On the pure electronics aspect of voltage or current issues for an amplifier, the previous poster is correct. It is great that you are building stuff, to move more into the understanding of design it seems to me that a deeper understanding of electronics would be great for you.
When I was a kid there were some good intro books I read, though they would be horribly outdated now, "understanding electronics" or some such. I would expect other members could recommend some online material.
I suggest this as in a power amplifier/speaker system. Volts, amps and watts are intimately related mixed in with a real mess of the speaker impedance.
On the subject of "sound" that is a whole different thing. A very subjective domain for which I rather doubt a technical basis exists - though even that might be disputed. I would endeavour to keep subjectivism separate to objectivism -or design.
I see a couple of very different threads to the original post.
On the pure electronics aspect of voltage or current issues for an amplifier, the previous poster is correct. It is great that you are building stuff, to move more into the understanding of design it seems to me that a deeper understanding of electronics would be great for you.
When I was a kid there were some good intro books I read, though they would be horribly outdated now, "understanding electronics" or some such. I would expect other members could recommend some online material.
I suggest this as in a power amplifier/speaker system. Volts, amps and watts are intimately related mixed in with a real mess of the speaker impedance.
On the subject of "sound" that is a whole different thing. A very subjective domain for which I rather doubt a technical basis exists - though even that might be disputed. I would endeavour to keep subjectivism separate to objectivism -or design.
some multiway loudspeaker crossovers cause impedance dips at certain frequencies - dipping to 1/2 the name plate speaker Z is impolite but happens, even worse infamous examples exist
but the current demand with special signals that pump the energy storing impedances and then abruptly reverse phase can be up to 6x the name plate Z calculated I
a basically competent audio amp needs to at least be able to drive 2x the current of the nominal power rating at the rated speaker load Z - briefly if not continuously
but the current demand with special signals that pump the energy storing impedances and then abruptly reverse phase can be up to 6x the name plate Z calculated I
a basically competent audio amp needs to at least be able to drive 2x the current of the nominal power rating at the rated speaker load Z - briefly if not continuously
Hans,
Hans, You still have a bit of understanding to do.
Pl ayes louder" What does that mean? For a knob setting it is louder? That may be only the gain of the amplifier. There are many many factors here. All things are never equal.
The stroke is longer because a higher VOLTAGE was applied to the coil. It will draw whatever current is required to supply that voltage unless the power supply is not capable of supplying that much current, in which case the voltage drops and the amplifier clips.
There are many good starting out tutorials on electronics on the WEB. Old books are fine as the laws of physics don't change. It is a bit too involved to learn in a Q&A forum.
Hans, You still have a bit of understanding to do.
Pl ayes louder" What does that mean? For a knob setting it is louder? That may be only the gain of the amplifier. There are many many factors here. All things are never equal.
The stroke is longer because a higher VOLTAGE was applied to the coil. It will draw whatever current is required to supply that voltage unless the power supply is not capable of supplying that much current, in which case the voltage drops and the amplifier clips.
There are many good starting out tutorials on electronics on the WEB. Old books are fine as the laws of physics don't change. It is a bit too involved to learn in a Q&A forum.
I'm sorry. The old JVC amp couldn't deliver much current, compared to to my gainclone. I have a 10" subwoofer, and with the gainclone the stroke is much longer that with my old JVC amp. I guess the stroke was smaller on the JVC because it couldn't deliver enough current (it was rated from 6-16 ohm, and my sub is 4 ohm)
Since my subwoofer is only 4 ohm, it will draw more current, and a high current amplifier is well suited for this subwoofer I guess.
Since my subwoofer is only 4 ohm, it will draw more current, and a high current amplifier is well suited for this subwoofer I guess.
Hi,
What you are talking about is DAMPING factor. That is what gives you punchy and quick bass. Do not contaminate your head with voltage and current. Looking for good amp with good bass? Search for Damping factor around 1000. In general, damping factor is output resistance, in more general is how amp can operate the driver and reduce all parasite oscillation.
Hi,
No. Your JVC could not deliver +/- 60V into 4 ohms.
The current limiting works by reducing the available
voltage, here probably to near +/- 30V if the current
limit is set to +/- 60V into 8 ohms, i.e. +/- 7.5 A peak.
rgds, sreten.
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Hi,
What you are talking about is DAMPING factor. That is what gives you punchy and quick bass. Do not contaminate your head with voltage and current. Looking for good amp with good bass? Search for Damping factor around 1000. In general, damping factor is output resistance, in more general is how amp can operate the driver and reduce all parasite oscillation.
I bet to differ. At this stage we are talking what voltage the amplifier can sustain into the load. DF is almost irrelevant to amplifier quality. Just one of those old easy to measure numbers that look good in an ad. Managing parasitic oscillations is a function of the output network and the amplifier feedback stability margins as set by the compensation.
"Punchy and quick" are also not what is going on. These are a function if cabinet design and frequency response.
Well, if the damping factor is not important for PUNCHY and QUICK bass, then connect resistor in serial with your speaker and tell me that there is no difference at all. Whether amp is working on speaker as a load which is driver + reactive filter, or amp working on driver+filter+resistor.🙂
There is also damping factor for speaker cabinet. That is how cabinet decelerate free oscillations.
http://www.crownaudio.com/media/pdf/amps/damping_factor.pdf
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If its bass we are talking , then current is whats needed , high current amplifiers delivers bass in spades ..
Hi,
The damping factor is near irrelevant once it gets
to > 25, and has nothing to do with parasitics.
rgds, sreten.
(> 50 for 4 ohm nominal loads.)
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Hi,
that is to say to amplify anything above 16 KHz and with Amp speed more that 5 V/sec is irrelevant as well. Cause we simply cant hear anything beyond these numbers. But still, everybody is trying to turn his Amp into RF transmitter😀
Everything is relevant when it comes to hi-end sound.
rgds
Hi,
No it isn't. That is just a poor excuse to claim a damping factor of
greater than ~ 1000 is important, < 0.01R, when it is meaningless
in all practical respects when looking at an amplifier if > 100.
Many high-end amplifiers have much lower numbers.
rgds, sreten.
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have to admit that our conversation came to the dead end 😀 lets drop and start talking about something else
Not really. The voltage does indeed drive the cone, but the amps that flow are the ratio of volts / impedance. So you can't influence them separately, they are connected through the speaker impedance.
You can only get 'more amps' by either more volts, or lower impedance.
BTW Quick bass is an oxymoron. The xover filter in the speaker will route the high-frequency components of a step signal to the midrange/tweeter, leaving the leisure slow moving stuff for the woofer.
It's the midrange/tweeter that give the music - including the low notes coming from the woofer - the 'quickness'.
Jan
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