Help me to understand this car audio amplifier...

[onemilimeter]

Found the following car audio amplifier on ebay...

[McHammer Mystic 5.1 Channel Car Amplifier Amp 3550W]

[Highlights]
4 x 350 W and 1 x 440 W RMS power (equivalent to 4 x 675 1 x 850 watts maximum Power)
Powerful, adjustable high and low-pass filter

[Features]
Frequency range: 10 - 40000 Hz ± 1dB
Depth Filter control range: 50 - 250 Hz (6/12dB)
Filter height adjustment range: 60 - 1200 Hz (6/12dB)
Input Sensitivity: 0.2 - 5 V
Signal to noise ratio (S / N):> 100 dB
THD: <0.03%
Power supply: 12 V - DC

[Questions]
[1] For "1 x 440W RMS power", is the connected load of the channel 4-ohm or 8-ohm?
[2] If the amplifier is capable of supplying 440W RMS power at 4-ohm, my calculation shows that the output RMS voltage is 42V. How can it supply 42V when its input power supply is only 12VDC?
[3] Can the output bypass the "high and low-pass filter"?
[4] What's the output power (in RMS) level at the given THD 0.03%?
[5] Will it accept higher input power supply, e.g. 14.4VDC?
[6] If the input signal is a sinewave, will the output be a sinewave too?

Thanks.

[Perry Babin]

Most of these can't be answered.

2. Most amps use a switching power supply to boost the voltage

5. Probably but why would you need it to accept higher voltages?

6. It will be a sine wave if the amp is in good working order and is not driven to clipping.

[onemilimeter]

Originally Posted by Perry Babin

5. Probably but why would you need it to accept higher voltages?
6. It will be a sine wave if the amp is in good working order and is not driven to clipping.

With higher input supply voltage, the amp will probably have wider dynamic range. Besides, I hope to find an amp which can give me higher output voltage. If you know any, kindly recommend.

I need the amp not for car audio or home audio entertainment. I need an amp to be acting as a variable-frequency variable-amplitude sinusoidal voltage source for laboratory testing. The output sinusoidal voltage given by signal generator is just not "strong" enough.

[timwebb]

u looked at crown amps?

[onemilimeter]

Originally Posted by timwebb

u looked at crown amps?

Thanks for your suggestion. I found the following on ebay:

CROWN MICRO-TECH MT600 AMPLIFIER
- FTC Continuous Average Power from 20 Hz to 20 kHz with No More than 0.1% THD.
- Micro-Tech 600: 220 watts into 8 ohms, 325 watts into 4 ohms, 400 watts into 2 ohms.
- Maximum Average Power at 1 kHz with No More than 0.1% THD:


The power given (e.g. 220 watts) is RMS or MAX?

[onemilimeter]

I note that for Crown audio amplifier the output power rating is always given at 1kHz. Typically, how much will this output power rating drop at 10kHz or 20kHz?

Thanks.

[luka]

Originally Posted by onemilimeter

Found the following car audio amplifier on ebay...

[McHammer Mystic 5.1 Channel Car Amplifier Amp 3550W]

[Highlights]
4 x 350 W and 1 x 440 W RMS power (equivalent to 4 x 675 1 x 850 watts maximum Power)
Powerful, adjustable high and low-pass filter

[Features]
Frequency range: 10 - 40000 Hz ± 1dB
Depth Filter control range: 50 - 250 Hz (6/12dB)
Filter height adjustment range: 60 - 1200 Hz (6/12dB)
Input Sensitivity: 0.2 - 5 V
Signal to noise ratio (S / N):> 100 dB
THD: <0.03%
Power supply: 12 V - DC

[Questions]
[1] For "1 x 440W RMS power", is the connected load of the channel 4-ohm or 8-ohm?
[2] If the amplifier is capable of supplying 440W RMS power at 4-ohm, my calculation shows that the output RMS voltage is 42V. How can it supply 42V when its input power supply is only 12VDC?
[3] Can the output bypass the "high and low-pass filter"?
[4] What's the output power (in RMS) level at the given THD 0.03%?
[5] Will it accept higher input power supply, e.g. 14.4VDC?
[6] If the input signal is a sinewave, will the output be a sinewave too?

Thanks.

1. It doesn't say, would have to be checked
2. it has supply in it, that converts 12v to higher voltages, to get that amount of output voltage for that power.
3. Output can't bypass, but YOU can bypass input (filters are before output stage). There is probably a switch, to select LPF, HPF or all pass... or something like that
4. depends on amp itself, would have to be measured... and 0.03 is pretty low, normal rating is up to 1% THD, to even hear the diffrence: Note: this is in most cases lowest THD they hit or THD at 1w of output power(no where max power)
5. Yes, car amps are rated at 14.4v, or 12v or 12.6v or something like that. Most have range from say 10v to 15 or 16v
6. Well that is the point of the amp, isn't it? Untill clip anyway