Zed sayed Blaaa blaaa bla

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jammin
Posts: 42
Joined: Sat Nov 17, 2012 6:14 pm

Zed sayed Blaaa blaaa bla

Post by jammin »

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.
----------------------------------------------------------------------------------------------------------

What do yall think about this ????????? ..... I say more heat more power ....
Last edited by jammin on Sun Nov 25, 2012 5:27 am, edited 2 times in total.
Audio control 3.1, EQX II, MPS-2500 x2, PPI A404 x3, The rest is top secret.

Sponcered by http://www.hiscarparts.com
Audiophiliac
Posts: 918
Joined: Mon Dec 18, 2006 9:41 pm
Location: Boise, ID

Re: Zed sayed Blaaa blaaa bla

Post by Audiophiliac »

Without getting into any argument, the quote you just posted is based on facts.

Power output of an amplifier is completely dependent on the design. Some will not do more power with more input voltage or with lower impedance loads. Others will do more power with more voltage and lower loads. Just depends on what the manufacturer is trying to accomplish.
ttocs
the Floor Sweeping Hack with Golden Ears
Posts: 14783
Joined: Fri Dec 19, 2008 9:53 pm

Re: Zed sayed Blaaa blaaa bla

Post by ttocs »

that zed dude has just been fakin it all these years. With out knowing the facts of what amp was for sale, what was said in the amp and what he said, still ain't care..... mantz has been known to reply to people on ebay I know so its all to together possible you are talking to him himself. If that were the case with me I would read more then I typed myself if that man is taking his time to try and educate me I would take advantage of it.
what else can I say I am a grumpy asshole most of the time.
jammin
Posts: 42
Joined: Sat Nov 17, 2012 6:14 pm

Re: Zed sayed Blaaa blaaa bla

Post by jammin »

By the way my phoenix gold amps sound cleaner all day long... My subs hit harder at 2 ohms bridged... Shoot I had 2 mojo dvc 4 ohms subs both bridged pos to pos and my mps 2500 never shut off and put out more power and liked it. So i bought another one and got 4 lj 12s to run mono on two amps and love it and mine put out more output at lower ohms and higher voltage.
Last edited by jammin on Sun Nov 25, 2012 5:10 am, edited 1 time in total.
Audio control 3.1, EQX II, MPS-2500 x2, PPI A404 x3, The rest is top secret.

Sponcered by http://www.hiscarparts.com
vladthebad
Posts: 169
Joined: Tue Dec 22, 2009 5:55 am

Re: Zed sayed Blaaa blaaa bla

Post by vladthebad »

It also depends a LOT on amp power supply. Fully regulated stuff doesn't do so well at low impedances generally, and rarely do amps have enough capacitance on the rails and the power supply input to really truly shine at low impedance loads. Plus look at all the extra heatsink your buying. MS2250 vs MS2250TA vs MS2125 vs MPS2500... Same sink. Same board. If I'm the one buying, and price is the same, I'd take the 2250 or the 2250TA. This isn't how many companies do it though. They'll give you an MS275 sized sink, and rate it like the MPS2500, or worse. You paid for all the extra wattage and parts, but got robbed on heatsink and sound quality. The xenon line with adaptive load, wasn't cheap, you bought the full heatsink, but you got the power at any load.. Phoenix gold and old school US amps, and old school orion though, were all fair, you weren't getting robbed of parts, or paying for 2250sx parts in hcca225/275sx heatsink... You either got the sx/xtr line, or the high current version as an hcca... Many companies don't do this. Where is the high voltage version of the audiobahn 2300hct (2400w, chrome, flames,etc) I would have LOVED the same (or maybe 1 size smaller) amp in a high voltage version. The biggest high voltage one they made for years that I know of was the A3200E and that was discontinued a few years before audiobahn started putting flames on crap. Btw: my a3200e sounds great... But damn it would have been nice to have an even bigger meaner higher voltage version.... With a bit more power supply beef if you did want to run it 4 ohm bridged.

Anyways, he has a good point, but in this case, you lose a hell of a lot less with the Mps than most other stuff loses. Give me the choice though, and I'm with mantz. Ill take the MS, the MAC over Mps or the SX/xtr over hcca any day. A billion watts at 1/4 ohm is worthless. 500-1000 at 4 ohm is far far more usable.

Of course, all sanity gets thrown out the window if we are just burping.. Then make it water cooled, ill prechill it, and the heatsink only had to be big enough for 10 seconds or so.
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