1)The legacy amplifier is not 4x400W ??
how do u get that the amp out only 25W RMS?
2)and The pyle amplifier is can on a two "Car subs" of 1200W at the full power of the subs??
* "Car Subs"
** I Talking about 4 Oma Speakers
how do u get that the amp out only 25W RMS?
2)and The pyle amplifier is can on a two "Car subs" of 1200W at the full power of the subs??
* "Car Subs"
** I Talking about 4 Oma Speakers
You have been told this many times
quote
1)The legacy amplifier is not 4x400W ??
how do u get that the amp out only 25W RMS?
What kind of watts. Real RMS watts or
super duper bull droppings pie in the sky watts.
Into 4 ohms the pyle is 2 x 250 watts RMS
Into 4 ohms the legacy is 4 x 50 watts RMS
quote
1)The legacy amplifier is not 4x400W ??
how do u get that the amp out only 25W RMS?
What kind of watts. Real RMS watts or
super duper bull droppings pie in the sky watts.
Into 4 ohms the pyle is 2 x 250 watts RMS
Into 4 ohms the legacy is 4 x 50 watts RMS
LA870 4-Channel Amplifier Specifications
· Power output
50 watts RMS x 4 (4 W load)
85 watts RMS x 4 (2 W load)
400 watts x 4 max output
800 watts x 2 max output (bridge mode)
400 watts x 2 + 800 watts x 1 max output (stereo + bridge mono mode)
· Frequency response: 10 to 30,000 Hz
· Input impedance
Low level inputs: 10k W
High level inputs: 100 W
· Input sensitivity
Low level inputs: 250 mV
High level inputs: 2.5 V
· Dimensions: 10.4" W x 2.6" H x 15.5" L
400 watts x 4 max output (what kind of watts are these)
· Power output
50 watts RMS x 4 (4 W load)
85 watts RMS x 4 (2 W load)
400 watts x 4 max output
800 watts x 2 max output (bridge mode)
400 watts x 2 + 800 watts x 1 max output (stereo + bridge mono mode)
· Frequency response: 10 to 30,000 Hz
· Input impedance
Low level inputs: 10k W
High level inputs: 100 W
· Input sensitivity
Low level inputs: 250 mV
High level inputs: 2.5 V
· Dimensions: 10.4" W x 2.6" H x 15.5" L
400 watts x 4 max output (what kind of watts are these)
What does the number of transistors in an amplifier
have to with anything?
Is counting the number of transistors important to you?
I can build a REAL 300 watt RMS into 4 ohms amplifier
with just one mj21195 and one mj21196 and a very
large heatsink.
quote
2)i have a car amp that i buy "400WX2" in the amp have a 8 transistors of 4-2SC5198 & 4-2SA1941... how mach RMS the amp? (the volt is 68VDC in the amp...)
More useless information. You DO NOT have a 400 watt x 2
rms into 4 ohm amplifer. You have another 50 watt per channel
cheap piece of trash. The voltage of the power supply once
again does not matter. Only in conjuntion with the amount
of current that it can deliver do you have an idea how
much power the device can deliver.
Look at rating on the input fuse to the amplifier. Lets assume
it is 20 amps. At 14 volts that is an absolute maximum of
280 watts before the fuse blows. This might be typical of
a 50 watt x 4 amplifier.
A real 400 watt x 2 rms into 4 ohms amplifier would have to
have a 60 ampere fuse.
have to with anything?
Is counting the number of transistors important to you?
I can build a REAL 300 watt RMS into 4 ohms amplifier
with just one mj21195 and one mj21196 and a very
large heatsink.
quote
2)i have a car amp that i buy "400WX2" in the amp have a 8 transistors of 4-2SC5198 & 4-2SA1941... how mach RMS the amp? (the volt is 68VDC in the amp...)
More useless information. You DO NOT have a 400 watt x 2
rms into 4 ohm amplifer. You have another 50 watt per channel
cheap piece of trash. The voltage of the power supply once
again does not matter. Only in conjuntion with the amount
of current that it can deliver do you have an idea how
much power the device can deliver.
Look at rating on the input fuse to the amplifier. Lets assume
it is 20 amps. At 14 volts that is an absolute maximum of
280 watts before the fuse blows. This might be typical of
a 50 watt x 4 amplifier.
A real 400 watt x 2 rms into 4 ohms amplifier would have to
have a 60 ampere fuse.
400W X 2 = 800W
At 70% efficency for a class B output stage that means 1142W out of the supply.
A 85% efficency switching supply would mean 1344W from the battery.
At 13.8V with the alternator running this would be 97.4A
With a real woofer with 45* phase angle it would probably draw 150A
So how big a fuse is on this thing?
At 70% efficency for a class B output stage that means 1142W out of the supply.
A 85% efficency switching supply would mean 1344W from the battery.
At 13.8V with the alternator running this would be 97.4A
With a real woofer with 45* phase angle it would probably draw 150A
So how big a fuse is on this thing?
DJK,
not many car amps use class 'b' output stages. Most amps use class 'ab' which are typically 40-55 percent efficient. Some mono (sub amps) are class d output stage, typically 80 percent efficient.
DJ of Israel,
Even if your amp was rated at 800 watts RMS into a 4 ohm load, you would have to be supplying the amp with between 55 & 65 amps of current from your charging system in your car.
Now we know that even if your car has for example a 90 amp alternator that there is systems in the car that demand from this current, such as your battery, headlights & air conditioning. With these items running, you would realistically get about 35 amps from your charging system ( I have tested this).
Now if you drop your load (impedence sicko!) to 2 ohms some amps will double their power, What the manufacture does not tell you is that the amp needs to draw twice as much current to produce that power, most cars charging systems do not have a hope in hell.
Finally, just as in home audio the same holds true in car audio, 50 good watts per channel (Rockford Fosgate, Phoenix Gold, Zapco etc) will be better than double the power from an amp like you talk about. (pyramid, legacy, etc.)
Thats all for now,
Cheers
KevinLee
not many car amps use class 'b' output stages. Most amps use class 'ab' which are typically 40-55 percent efficient. Some mono (sub amps) are class d output stage, typically 80 percent efficient.
DJ of Israel,
Even if your amp was rated at 800 watts RMS into a 4 ohm load, you would have to be supplying the amp with between 55 & 65 amps of current from your charging system in your car.
Now we know that even if your car has for example a 90 amp alternator that there is systems in the car that demand from this current, such as your battery, headlights & air conditioning. With these items running, you would realistically get about 35 amps from your charging system ( I have tested this).
Now if you drop your load (impedence sicko!) to 2 ohms some amps will double their power, What the manufacture does not tell you is that the amp needs to draw twice as much current to produce that power, most cars charging systems do not have a hope in hell.
Finally, just as in home audio the same holds true in car audio, 50 good watts per channel (Rockford Fosgate, Phoenix Gold, Zapco etc) will be better than double the power from an amp like you talk about. (pyramid, legacy, etc.)
Thats all for now,
Cheers
KevinLee
From djk's numbers which are certainly reasonable, a 50
amp fuse would mean at most 200 watts per channel x 2.
Speaker load impedance will not matter.
14 volts * 50 amps * .7 *.85 === about 400 watts total.
And in fact it is less than that because a 50 amp fuse
is really rated at only 50 * .8 amps continuous.
amp fuse would mean at most 200 watts per channel x 2.
Speaker load impedance will not matter.
14 volts * 50 amps * .7 *.85 === about 400 watts total.
And in fact it is less than that because a 50 amp fuse
is really rated at only 50 * .8 amps continuous.
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