Ohms affect sound? Yes or no?
01-03-2009, 09:39 PM
#21
You'll need a stobe light and a camera that can open the shutter very quickly in rapid succession to realize it. One will reach it's maximum before the next because of it being out of phase by 45 degrees. If one gets there before the next, then accoustically, they will be out of sync with each other, therefore making a time delayed sound effect.
You'll see the sub getting the power first to be quicker than the next.
It's the biggest reason that SPL'ers put theirs in parallel.
It's also the reason that the "old timers" are not sticking their necks into this. It's all theory!
You'll see the sub getting the power first to be quicker than the next.
It's the biggest reason that SPL'ers put theirs in parallel.
It's also the reason that the "old timers" are not sticking their necks into this. It's all theory!
There is also entertainment value in watching people split hairs down to nanometer widths over something you probably can't hear in your car driving down one of the pothole ridden roads in the GTA, but that's another issue.....
Sorry for interrupting........do carry on.....
01-04-2009, 07:35 AM
#22
500 Watt CAFz'r
Join Date: Jan 2008
Posts: 537
You'll need a stobe light and a camera that can open the shutter very quickly in rapid succession to realize it. One will reach it's maximum before the next because of it being out of phase by 45 degrees. If one gets there before the next, then accoustically, they will be out of sync with each other, therefore making a time delayed sound effect.
You'll see the sub getting the power first to be quicker than the next.
It's the biggest reason that SPL'ers put theirs in parallel.
You'll see the sub getting the power first to be quicker than the next.
It's the biggest reason that SPL'ers put theirs in parallel.
01-04-2009, 07:45 AM
#23
500 Watt CAFz'r
Join Date: Jan 2008
Posts: 537
That said, there would definitely be a change in the QES, and therefore the QTS but in my opinion not to a significant degree. If you plugged the different scenarios into a box design software I bet you'd see no significant difference. What this all comes down to is that there is a difference due to both amp and wiring but can one hear it?
01-04-2009, 07:54 AM
#24
Yankee
Join Date: Oct 2003
Posts: 3,599
The current will be in phase (shift effect) so how can they be acoustically phase shifted? Which one will lead the other?
Coils exhibit phase shift between voltage and current with voltage leading. Two coils in series will exhibit the same shift as one coil of the summed value. Think of it in this case as one big voice coil. There can be no relative difference.
Coils exhibit phase shift between voltage and current with voltage leading. Two coils in series will exhibit the same shift as one coil of the summed value. Think of it in this case as one big voice coil. There can be no relative difference.
would more current increase the inductance or would you need to add turns to the coil?
Last edited by JohnVroom; 01-04-2009 at 07:57 AM.
01-04-2009, 10:28 AM
#26
500 Watt CAFz'r
Join Date: Sep 2008
Posts: 723
Rated Power: 500 W RMS @ 1.5 ohm - 4 ohm (11V-14.5V)
THD at Rated Power: <0.05% @ 4 ohm
Damping Factor: >500 @ 4 ohm / 50 Hz - >250 @ 2 ohm / 50 Hz
Here's some of the ratings on the amp taken from the JL Audio site.
For his particular application running the sub at 2 ohm will yield 500W from the amp, while wiring for 8 ohm will result in less output.
I've heard a few people mention the damping factor before. I'm not sure what these numbers actually designate. 500 @ 4 ohm, and 250 @ 2 ohm. Obviously there's twice as much damping with the higher resistance - though I'd like clarification as to what those numbers correspond with. From what I understand the higher the damping factor the more controlled the circuit is, resulting in a subwoofer that behaves more ideally.
For this particular amp, his best bet would be to find a subwoofer that will create a 4 ohm load. This would allow use of the 500W, while also creating a higher damper factor.
But what the hell do I know.
THD at Rated Power: <0.05% @ 4 ohm
Damping Factor: >500 @ 4 ohm / 50 Hz - >250 @ 2 ohm / 50 Hz
Here's some of the ratings on the amp taken from the JL Audio site.
For his particular application running the sub at 2 ohm will yield 500W from the amp, while wiring for 8 ohm will result in less output.
I've heard a few people mention the damping factor before. I'm not sure what these numbers actually designate. 500 @ 4 ohm, and 250 @ 2 ohm. Obviously there's twice as much damping with the higher resistance - though I'd like clarification as to what those numbers correspond with. From what I understand the higher the damping factor the more controlled the circuit is, resulting in a subwoofer that behaves more ideally.
For this particular amp, his best bet would be to find a subwoofer that will create a 4 ohm load. This would allow use of the 500W, while also creating a higher damper factor.
But what the hell do I know.
01-04-2009, 11:03 AM
#27
500 Watt CAFz'r
Join Date: Jan 2008
Posts: 537
Rated Power: 500 W RMS @ 1.5 ohm - 4 ohm (11V-14.5V)
THD at Rated Power: <0.05% @ 4 ohm
Damping Factor: >500 @ 4 ohm / 50 Hz - >250 @ 2 ohm / 50 Hz
Here's some of the ratings on the amp taken from the JL Audio site.
For his particular application running the sub at 2 ohm will yield 500W from the amp, while wiring for 8 ohm will result in less output.
I've heard a few people mention the damping factor before. I'm not sure what these numbers actually designate. 500 @ 4 ohm, and 250 @ 2 ohm. Obviously there's twice as much damping with the higher resistance - though I'd like clarification as to what those numbers correspond with. From what I understand the higher the damping factor the more controlled the circuit is, resulting in a subwoofer that behaves more ideally.
For this particular amp, his best bet would be to find a subwoofer that will create a 4 ohm load. This would allow use of the 500W, while also creating a higher damper factor.
But what the hell do I know.
THD at Rated Power: <0.05% @ 4 ohm
Damping Factor: >500 @ 4 ohm / 50 Hz - >250 @ 2 ohm / 50 Hz
Here's some of the ratings on the amp taken from the JL Audio site.
For his particular application running the sub at 2 ohm will yield 500W from the amp, while wiring for 8 ohm will result in less output.
I've heard a few people mention the damping factor before. I'm not sure what these numbers actually designate. 500 @ 4 ohm, and 250 @ 2 ohm. Obviously there's twice as much damping with the higher resistance - though I'd like clarification as to what those numbers correspond with. From what I understand the higher the damping factor the more controlled the circuit is, resulting in a subwoofer that behaves more ideally.
For this particular amp, his best bet would be to find a subwoofer that will create a 4 ohm load. This would allow use of the 500W, while also creating a higher damper factor.
But what the hell do I know.
Since a speaker's motor has a permanent magnet and a coil, it has the ability to generate voltage from it's movement (can act as a microphone). This movement can result from sound hitting the cone or from the momentum of the cone, ex: after a bass note has passed. The amp compares the voltage on the speaker wires to it's input signal (with scaling) and determines what does not belong. It then places a voltage of equal and opposite polarity on the ouput to cancel it. This will "short" the speaker's ouput and load it's motor (generator in this case) heavily and quickly reduce the stored energy to zero. The higher the damping factor the better it's able to do this, but don't be fooled into thinking that a damping factor of 500 will give it an iron grip on the voice coil. This is never the case in reality. Above 200 there is little gain in control.
01-04-2009, 11:04 AM
#28
I'm not sure on the specifics here, but I remember something about damping factors.
It has to do with how much the voltage drops when the amp isn't under any load (nothing connected to the terminals) vs. when a load is applied to the terminals. I just don't know how they get their final numbers though. But, it's possible for an amp to put out 20V, but then, when you hook up a speaker to it, you'll only be getting 19.5V because of the resistance caused by the higher current going through the circuit.
EDIT : Well, according to what kevmurray put up, I might be completely wrong, but I'll leave it up just to see if there's someone else who knows what the hell I'm talking about and can correct my statement.
It has to do with how much the voltage drops when the amp isn't under any load (nothing connected to the terminals) vs. when a load is applied to the terminals. I just don't know how they get their final numbers though. But, it's possible for an amp to put out 20V, but then, when you hook up a speaker to it, you'll only be getting 19.5V because of the resistance caused by the higher current going through the circuit.
EDIT : Well, according to what kevmurray put up, I might be completely wrong, but I'll leave it up just to see if there's someone else who knows what the hell I'm talking about and can correct my statement.
Last edited by sirsleepsalot; 01-04-2009 at 11:06 AM.
01-04-2009, 11:14 AM
#29
Yankee
Join Date: Oct 2003
Posts: 3,599
This is a tangent (for big reds amusement):
From Wikipedia-Inductance (L) (measured in henries) is an effect resulting from the magnetic field that forms around a current-carrying conductor that tends to resist changes in the current. Electric current through the conductor creates a magnetic flux proportional to the current. A change in this current creates a change in magnetic flux that, in turn, by Faraday's law generates an electromotive force (EMF) that acts to oppose this change in current. Inductance is a measure of the amount of EMF generated for a unit change in current. For example, an inductor with an inductance of 1 Henry produces an EMF of 1 volt when the current through the inductor changes at the rate of 1 ampere per second. The number of loops, the size of each loop, and the material it is wrapped around all affect the inductance. For example, the magnetic flux linking these turns can be increased by coiling the conductor around a material with a high permeability such as iron. This can increase the inductance by 2000 times, although less so at high frequencies.
Thus: Inductance is a factor of the MAGNETIC field, the stronger the magnetic field the more energy is stored in the form of EMF that will oppose a change in I flow. Thus the more I the stronger the field, the more turns in an inductor the larger the field.
Back to topic: By going from serial (8ohm) to parallel (2 ohm) coils you altered R (thus increasing I flow) and also by adding parallel inductors (voice coils) lowered the system L and nominally increased system capacitance. So we have fewer inductor turns and more I. So if there were to be a change in sound quality it is due to the change in the load (subwoofer) not the source (amplifier) and given the limited freq band would tend to mask any differences, also the amplifier would also mask differences due to its high speed voltage and current regulation.
v=2 (Pi) FL x I x cos (2(Pi)x Ft)
I think this works with Lenz, ampere, Kirchhoff
And the complexity of the CEMF is why damping factor decreases with current
From Wikipedia-Inductance (L) (measured in henries) is an effect resulting from the magnetic field that forms around a current-carrying conductor that tends to resist changes in the current. Electric current through the conductor creates a magnetic flux proportional to the current. A change in this current creates a change in magnetic flux that, in turn, by Faraday's law generates an electromotive force (EMF) that acts to oppose this change in current. Inductance is a measure of the amount of EMF generated for a unit change in current. For example, an inductor with an inductance of 1 Henry produces an EMF of 1 volt when the current through the inductor changes at the rate of 1 ampere per second. The number of loops, the size of each loop, and the material it is wrapped around all affect the inductance. For example, the magnetic flux linking these turns can be increased by coiling the conductor around a material with a high permeability such as iron. This can increase the inductance by 2000 times, although less so at high frequencies.
Thus: Inductance is a factor of the MAGNETIC field, the stronger the magnetic field the more energy is stored in the form of EMF that will oppose a change in I flow. Thus the more I the stronger the field, the more turns in an inductor the larger the field.
Back to topic: By going from serial (8ohm) to parallel (2 ohm) coils you altered R (thus increasing I flow) and also by adding parallel inductors (voice coils) lowered the system L and nominally increased system capacitance. So we have fewer inductor turns and more I. So if there were to be a change in sound quality it is due to the change in the load (subwoofer) not the source (amplifier) and given the limited freq band would tend to mask any differences, also the amplifier would also mask differences due to its high speed voltage and current regulation.
v=2 (Pi) FL x I x cos (2(Pi)x Ft)
I think this works with Lenz, ampere, Kirchhoff
And the complexity of the CEMF is why damping factor decreases with current
Last edited by JohnVroom; 01-04-2009 at 11:18 AM.
