Fwd: Re: Headrest speakers... head unit wiring..... Also Arg

[poison]

Hi Lyndon

Yes we both seem to be saying the same thing, W=E2/R is the same as W=V2/R, as
E is Voltage and V is the unit, they are both representations of voltage
(depending on which school you went to), and the same for current, this will
often be expressed in a formula as I being Current or A being the unit of
Amps, also both correct. And again for Power, some schools use P for the
descriptor and of course W for the units.


I also agree that blowing big bucks on brands of huge speaker cables such as
Monster Cable is a waste of money, but at the same time if you are using a
high powered amp you should use a sensible larger speaker cable, there are
good very cheap cables on the market. Given that a speaker is a reactive load
with an impedence of only 4ohms then any additional losses in the cable can
have an impact on quality. But if I understand you correctly (sorry if not)
you say cable size is not an issue, so I ask, would you install a 300W amp and
sub combo into your car with the thinnest cable you could buy as this would be
cheaper? No of course not, you would put in a nice big cable, so size is
important (and I also agree they can be very overrated by many, ie OFC,
co-axial, multi-conductor mix, low Cap etc etc ).


Disclaimer:


The statement "Size is important" is in no way intended to cause stress or
concern to zorruno, I mean you did buy the biggest cell phone on the market for
a reason didn't you when everyone else wants the smallest. It's OK!!!... Ha
ha J


Gazza


Argentina & Japanese Anime

While I am writing


a) Has anyone been to Argentina, I'm thinking of going and would love to talk
to someone (a kiwi's perspective, I have many Argentinean friends).


b) Does anyone collect or is interested in Japanese Anime? I'd be keen to hear
form you.




Cheers


Gazza

[poison]

Hi Lyndon

Reluctant as I am, I'm going to reply within the text... (DAMN!!!) BUT NOT AT
THE END... there's a difference you know
----- Original But if I understand you correctly (sorry if not) you say
cable size is not an issue, so I ask, would you install a 300W amp and sub
combo into your car with the thinnest cable you could buy as this would be
cheaper? No of course not, you would put in a nice big cable, so size is
important (and I also agree they can be very overrated by many, ie OFC,
co-axial, multi-conductor mix, low Cap etc etc ).

No, that's not what I said. I said that we do not consider speaker

cable losses during the design process of an audio amplifier, whether it be in
a car system of any application. Such losses are only cosidered during
implementation of the product and are not considered as part of the equasion
during design. You can't plan power output for a given load impedance and
consider variables that may not exist. --- If you want 50 watts into 8 ohms
then you design your circuitry to achieve 20volts RMS accross an 8 ohm load at
onset of clipping.


That I agree on, we're looking at it from different ends, your looking
from the amp design and of course you can't design for unknowns, but I must
admit I could only design a very basic amp so you're way ahead of me there. My
perspective was as the end user, the guy who glues it all together by the best
(or easiest) practical means.


???Here's a poser for you -- Considering your example of a 2 volt drop
drop in the power lead to a car stereo. Given that most stereo's output pairs
operate in class AB and draw only milliamps when idle but draw max current at
full volume, doesn't that mean that the voltage drop acsoss the lossy power
cable will vary with the amplitude if the music? A most undesirable situation
don't you think?


I'd have to say yes, even though I have to admit I understand the
principles of A and B classes but the AB always confused me. And yes the more
volume, the more current draw and the greater the voltage drop, hence the
dimming of the stereo lights on the bass beats (lower frequency making a
longer current draw I would imagine) becuase of an undersized cable. As to the
differences in operation between say a class A and an AB I can't say I've ever
considered it. As I said I tested them, installed them and worked them hard,
never had to design them.


Gazza

[Lyndon Pope]

Good answer and an interesting discussion. Thanks.
Lyndon