Mostly: U = R x I -- I'm not joking .....
As you are educated you might know how to search?
But mostly U = R x I will do the job.
And sometimes a little P = U x I
If you hang around here long enough
you will soon be "in it" all.
----------------------
Some real ADVANCED PERSONS, (not Nelson Pass - amazingly! - he is probably to clever for that)
have reach so far that they are totally lost
in formulas that noone else understands
and that no longer relate to REAL WORLD AUDIO.
Try to avoid to go there - it is a serious illness!
You yourself are totally unaware - while others just smile at you.
-----------------------
Stay with the basic.
Whatever formulas you like to associate with
Current just keeps on creating Voltages over Resistances
whether it is Alternating Current, AC, or Direct Current, DC.
-----------------------
And things will stay that way a long time from now.
##############################################################
halo - don't mind people smiling at his words
I don't feel like searching the web for a tutorial.Kon said:thank you... but i already knew that stuff. i did physics in high school.
any help plz?
As you are educated you might know how to search?
But mostly U = R x I will do the job.
And sometimes a little P = U x I
If you hang around here long enough
you will soon be "in it" all.
----------------------
Some real ADVANCED PERSONS, (not Nelson Pass - amazingly! - he is probably to clever for that)
have reach so far that they are totally lost
in formulas that noone else understands
and that no longer relate to REAL WORLD AUDIO.
Try to avoid to go there - it is a serious illness!
You yourself are totally unaware - while others just smile at you.
-----------------------
Stay with the basic.
Whatever
formulas you like to associate with Current just keeps on creating Voltages over Resistances
whether it is Alternating Current, AC, or Direct Current, DC.
-----------------------
And things will stay that way a long time from now.
##############################################################
halo -
don't mind people smiling at his words again, very little towards wat i need...
here's my story
i am buying a set of speakers/subs and an amp for my car. i am reaing specs and amps are talking about 100W@4ohms or 150W@8ohms or wateva... (ps not real numbers, just approx) now i need to understand wat i need...
say i have a 4x100W @4ohms, can i have 4 speakers with power 100W AND a sub ??? ??? or something different???
i basically want to know the relationship between amp-speakers-subs and the W, Ohms, etc....
plz
here's my story
i am buying a set of speakers/subs and an amp for my car. i am reaing specs and amps are talking about 100W@4ohms or 150W@8ohms or wateva... (ps not real numbers, just approx) now i need to understand wat i need...
say i have a 4x100W @4ohms, can i have 4 speakers with power 100W AND a sub ???
??? or something different???i basically want to know the relationship between amp-speakers-subs and the W, Ohms, etc....
plz
Refine your question
- Preferable one specific question at the time. (Or two)
- Give as much facts as possible
- You will get more interested, if you post a diagram or picture
to illustrate the subject.
The more specific you are in your question
the better answer you get.
--------------------------------------------------
Halo - has seen it work this way - here at the Forum
(some people are impossible to reply to - they do not know how to ask)
You need to refine your way to ask.Kon said:again, very little towards wat i need...
here's my story
i am buying a set of speakers/subs and an amp for my car. i am reaing specs and amps are talking about 100W@4ohms or 150W@8ohms or wateva... (ps not real numbers, just approx) now i need to understand wat i need...
say i have a 4x100W @4ohms, can i have 4 speakers with power 100W AND a sub ???
i basically want to know the relationship between amp-speakers-subs and the W, Ohms, etc....
plz
- Preferable one specific question at the time. (Or two)
- Give as much facts as possible
- You will get more interested, if you post a diagram or picture
to illustrate the subject.
The more specific you are in your question
the better answer you get.
--------------------------------------------------
Halo - has seen it work this way - here at the Forum
(some people are impossible to reply to - they do not know how to ask)
Well, I'll take a stab at what Kon wants.
Most car speakers are 4 ohms. Most car amps deliver their highest power into a 4 ohm load.
An amp rated for 4 ohms can in fact drive an 8 ohm speaker. However, it will not deliver it's highest power into it. So an amp rated as 150 watts into 4 ohms might deliver just 75 watts into 8 ohms.
If you hook two 4 ohm speakers together in series you get an 8 ohm load. If you hook them together in parallel you get a 2 ohm load. Some of today's better car amps deliver their highest power rating into 2 ohm loads, actually. This is a departure from the traditional 4 ohm load for car speakers. Indeed, there are now some car subs that are actually rated at 2 ohms. Check that when you buy your speakers and subs.
There is an advantage to listing the Sound Pressure Level of a speaker with an "@ 2.83 Volts" listing. Actually, this is confusing. The lower the impedance, the more current a speaker draws at 2.83 Volts, hence more power is drawn, hence a higher "SPL @ 2.83 Volts" rating. But the speaker is really not more sensitive or efficient!
At 2.83 Volts, an 8 ohm speaker draws 1 watt, a 4 ohm speaker draws 2 watts, a 2 ohms speaker draws 4 watts. So the 4 ohm speaker will appear to be 3 dB more sensitive than the 8 ohm, and the 2 ohm speaker will appear to be 3 dB more senstitive than the 4 ohm. But they are not-they are merely drawing more power at the measured voltage. They still play the same SPL at 1 watt.
Speakers actually should be rated "@ 1 Watt", and some car speaker manufacturers, notably Blaupunkt and others, do it that way. But be aware of the SPL measured "@ 1W/1M" if the speaker is a 4 ohm or 2 ohm speaker. As stated before, the speaker wil not be playing at one watt at that voltage level.
Actual impedance is usually about 25% higher than the DC resistance. So if a speaker has a DC resistance of 2.8 ohms, it will be close enough to a 4 ohm speaker. But if the speaker has a DC resisitance of 1.8 ohms, then it really should be called a 2 ohm speaker, and might blow a 4 ohm amplifier.
Any other questions, please let me know.
Most car speakers are 4 ohms. Most car amps deliver their highest power into a 4 ohm load.
An amp rated for 4 ohms can in fact drive an 8 ohm speaker. However, it will not deliver it's highest power into it. So an amp rated as 150 watts into 4 ohms might deliver just 75 watts into 8 ohms.
If you hook two 4 ohm speakers together in series you get an 8 ohm load. If you hook them together in parallel you get a 2 ohm load. Some of today's better car amps deliver their highest power rating into 2 ohm loads, actually. This is a departure from the traditional 4 ohm load for car speakers. Indeed, there are now some car subs that are actually rated at 2 ohms. Check that when you buy your speakers and subs.
There is an advantage to listing the Sound Pressure Level of a speaker with an "@ 2.83 Volts" listing. Actually, this is confusing. The lower the impedance, the more current a speaker draws at 2.83 Volts, hence more power is drawn, hence a higher "SPL @ 2.83 Volts" rating. But the speaker is really not more sensitive or efficient!
At 2.83 Volts, an 8 ohm speaker draws 1 watt, a 4 ohm speaker draws 2 watts, a 2 ohms speaker draws 4 watts. So the 4 ohm speaker will appear to be 3 dB more sensitive than the 8 ohm, and the 2 ohm speaker will appear to be 3 dB more senstitive than the 4 ohm. But they are not-they are merely drawing more power at the measured voltage. They still play the same SPL at 1 watt.
Speakers actually should be rated "@ 1 Watt", and some car speaker manufacturers, notably Blaupunkt and others, do it that way. But be aware of the SPL measured "@ 1W/1M" if the speaker is a 4 ohm or 2 ohm speaker. As stated before, the speaker wil not be playing at one watt at that voltage level.
Actual impedance is usually about 25% higher than the DC resistance. So if a speaker has a DC resistance of 2.8 ohms, it will be close enough to a 4 ohm speaker. But if the speaker has a DC resisitance of 1.8 ohms, then it really should be called a 2 ohm speaker, and might blow a 4 ohm amplifier.
Any other questions, please let me know.
I am also greatful for Kelticwizard, making this good explanation.Kon said:YIPEEE!!! Thank you somuch KelticWizard... that was the explanation i needed... im forever in ur debt...
sorry halojoy, you were right i didnt word my question right..
YAY
I am often to impatient to do like him.
---------------------------------------------------
But just by making such "a little tips" as I did
I have, at several occations:
1) made someone rephrase his Q, and post some more facts/diagram
2) put the focus onto the thread! - it is placed on top of the list!
3) making some remarks - that give initial info - and sets the direction of the discussion
In that way I find I have helped a number of people
although the most substancial information/help
was giving buy my comrades - here at DIYAUDIO.
-----------------------------------------------------------------
We have specialists & experts in so many areas/subjects.
I see myself more as a link - some sort of GREASE that makes other things work well
- calling these guys to the place, where they can contribute
in this great MOTOR-engine called www.diyaudio.com
sometimes all that is needed is a friendly post
some nice words -
show a person, someone have noticed his Question
/halo - sometimes a very nice & helpful man
- handles the spotlights shining on you ...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.