Zed sayed Blaaa blaaa bla
Posted: Sat Nov 24, 2012 7:25 pm
I had to post this after a conversation that i had with zed on ebay. Here is what zed sayed about 1 ohm read this....
This is off zed web ste..
Well now that I mention “1 ohm”, I cannot resist getting into this subject. Scenario: Kid (or
middle aged person) buys gizzilion watt amplifier with manufacturer’s specifications of x
watts into 4 ohm, y watts into 2 ohm and z watts into 1 ohm. Well let’s take a wild guess
and I bet you all that the vast majority will drive the amplifier into 1 ohm. Why? Easy, he
feels that he is getting his “moneys worth” by doing this. OK let’s see what reality is. Said
amplifier is maybe rated at say 600w into 4 ohm, 1000w into 2 ohm and 1500w into 1
ohm. We will assume that the speaker impedance is resistive. The difference between the
4 and 2 ohm power is 2.2dB, the difference between the 2 and 1 ohm power is 1.76dB
and the difference between 4 and 1 ohm power is 3.9dB. So what do these numbers tell
us. First if the speaker is 4 ohms vs 2 ohms, no way you can hear any difference. Same
issue comparing 2 as to 1 ohm. I grant you that between 4 and 1 ohm there is almost 4dB
difference BUT at what price and this difference is just percebtible! Two issues. Low
impedance loads affect the amplifier’s sound quality adversely and this is quite easy to
prove. Load an amplifier with a 4 ohm woofer and listen. Add parallel resistors to the
speaker to make the amplifier “think” that it is driving a low impedance speaker and listen
to the difference in sound quality. You will be surprised. This test is not 100% valid in fact
as the resistive loads added, let the amplifier off the hook as the reactive components of
the load are confined to the 4 ohm part. The idea of this test is to keep the loudness about
constant but load down the amplifier.
The average person can just perceive a 3dB (doubling of power) difference and to actually
double the sound pressure on your eardrum, you require TEN TIMES the amplifier power.
Yes TEN TIMES!
The other consequence of driving amplifiers into these ridiculously low impedances is that
the amplifier is stressed substantially more as compared to when driven into more sane
impedances. Efficiency drops as the losses in the output stages increase dramatically
even with “super efficient” class D amplifiers.
It
serves ONLY to boost the ego of the owner of the car so he can quote numbers to his
buddies.
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What do yall think about this ????????? ..... I say more heat more power ....
This is off zed web ste..
Well now that I mention “1 ohm”, I cannot resist getting into this subject. Scenario: Kid (or
middle aged person) buys gizzilion watt amplifier with manufacturer’s specifications of x
watts into 4 ohm, y watts into 2 ohm and z watts into 1 ohm. Well let’s take a wild guess
and I bet you all that the vast majority will drive the amplifier into 1 ohm. Why? Easy, he
feels that he is getting his “moneys worth” by doing this. OK let’s see what reality is. Said
amplifier is maybe rated at say 600w into 4 ohm, 1000w into 2 ohm and 1500w into 1
ohm. We will assume that the speaker impedance is resistive. The difference between the
4 and 2 ohm power is 2.2dB, the difference between the 2 and 1 ohm power is 1.76dB
and the difference between 4 and 1 ohm power is 3.9dB. So what do these numbers tell
us. First if the speaker is 4 ohms vs 2 ohms, no way you can hear any difference. Same
issue comparing 2 as to 1 ohm. I grant you that between 4 and 1 ohm there is almost 4dB
difference BUT at what price and this difference is just percebtible! Two issues. Low
impedance loads affect the amplifier’s sound quality adversely and this is quite easy to
prove. Load an amplifier with a 4 ohm woofer and listen. Add parallel resistors to the
speaker to make the amplifier “think” that it is driving a low impedance speaker and listen
to the difference in sound quality. You will be surprised. This test is not 100% valid in fact
as the resistive loads added, let the amplifier off the hook as the reactive components of
the load are confined to the 4 ohm part. The idea of this test is to keep the loudness about
constant but load down the amplifier.
The average person can just perceive a 3dB (doubling of power) difference and to actually
double the sound pressure on your eardrum, you require TEN TIMES the amplifier power.
Yes TEN TIMES!
The other consequence of driving amplifiers into these ridiculously low impedances is that
the amplifier is stressed substantially more as compared to when driven into more sane
impedances. Efficiency drops as the losses in the output stages increase dramatically
even with “super efficient” class D amplifiers.
It
serves ONLY to boost the ego of the owner of the car so he can quote numbers to his
buddies.
----------------------------------------------------------------------------------------------------------
What do yall think about this ????????? ..... I say more heat more power ....