That's the way I understood it - the OP was looking at it as though one was push, and the other pull (from a somewhat DC perspective), not one being both push and pull, and the other being the middle (from an AC perspective).
When in fact, polarity doesn't even matter, unless there is a phase relationship with another speaker involved. In any case the amp couldn't care less which way 'round you hooked it up.
I agree and as I confirmed in post #12, taken in context (explanation of an instantaneous positive half-cycle condition ONLY, described as a "push" by the OP), I can see no reason why the description I gave using a polarity designation might be considered incorrect. For the positive half-cycle, the red-coloured terminal becomes positive with respect to the negative terminal. Had the question been centered around complete cycles, i.e. AC, then the polarity factor would have been relatively meaningless other than for ensuring loudspeaker phase matching.
I still don't accept the push pull explanation.
The output terminal at the back of the amplifier is the Hot terminal. It provides the Push.
The Ground or return terminal on the back of the amplifier is effectively passive or Neutral. It has no push.
When the load is connected the Hot terminal provides the EMF that sends current around the circuit that ends up back at the Return terminal.
It makes no difference whether that circuit passes DC current due to a DC emf or is AC current due to an AC emf.
The only bit that Sy pointed out, that I now agree was wrong, was the reference to "positive & negative"
The output terminal at the back of the amplifier is the Hot terminal. It provides the Push.
The Ground or return terminal on the back of the amplifier is effectively passive or Neutral. It has no push.
When the load is connected the Hot terminal provides the EMF that sends current around the circuit that ends up back at the Return terminal.
It makes no difference whether that circuit passes DC current due to a DC emf or is AC current due to an AC emf.
The only bit that Sy pointed out, that I now agree was wrong, was the reference to "positive & negative"
I'm not going to try to give an answer to all posts I don't have time!
550V is the max the resistor can handle it doesn't dictate to current capability. Current through the resistor can be calculated by...
Total lowest impedance from the resistor and driver will be about 4ohm. your amplifier is capable of 22W into 4ohm (I could be wrong I haven't read everything that deeply) to achieve 22Wrms into 4ohm requires about 9.38Wrms.
22/9.38 gives 2.35A going through the resistor which is fine. half the power will be spilt most of the time between the resistor and driver so if you had 22Wrms of sine running through it you will have 11W dumped in each.
I suggest you forget about amplifiers and speakers for a couple of years go an learn the basics and I mean very basic basics then come back and things will make sense.
Does a push/pull amp just not source current from V+ through the output transistor through the driver to ground? Then sink current from ground through the driver through the output transistor to V-?
The red terminal is providing all the grunt/volts whether they are positive or negative and source/sink current to ground.
Hi,
Assuming black is neutral or earth then red is the "hot" terminal.
For AC red must push or source current and pull or sink current.
Black being neutral therefore sinks pushed/sourced current and
sources pulled/sinked current, all driven by the red voltage.
Related to the original question : yes you can put a 2R resistor in series
with a 2R driver, it will do horrible things to the bass Q of the driver.
Doesn't matter if it is before or after the driver. that gives 4 ohms.
22W into 4 ohms = ~ 11W to the speaker.
By putting a 2R resistor in both leads you have effectively added 4R
and made the bass drivers Q even worse and have a load of 6 ohms.
22W into 4 ohms = ~ 15W into 6 ohms = ~ 5W into the speaker.
rgds, sreten.
Assuming black is neutral or earth then red is the "hot" terminal.
For AC red must push or source current and pull or sink current.
Black being neutral therefore sinks pushed/sourced current and
sources pulled/sinked current, all driven by the red voltage.
Related to the original question : yes you can put a 2R resistor in series
with a 2R driver, it will do horrible things to the bass Q of the driver.
Doesn't matter if it is before or after the driver. that gives 4 ohms.
22W into 4 ohms = ~ 11W to the speaker.
By putting a 2R resistor in both leads you have effectively added 4R
and made the bass drivers Q even worse and have a load of 6 ohms.
22W into 4 ohms = ~ 15W into 6 ohms = ~ 5W into the speaker.
rgds, sreten.
What part of the second reply is incorrect? Aside from the fact that he is quoting part of currentflow's reply, but in reading further up in flow's post...
...it's quite obvious that both parties understand the true function of the terminals.
-----------------------------------------------------------------------
AndrewT - Which push/pull explanation do you not accept? please quote ;-)
I'd be more apt to scratch my head at the following combination of statements...
...as one has nothing to do with the other.
Attached is an image from melab-bd that I keep on my phone, to show customers when trying to explain how their amp works - in fact, the whole site may be of benefit to the OP.
Attachments
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hi.
i know of the power being wasted to the resistor.
but
look at what i am looking at.
it cost me $10 for those speakers at the junkyard, and the regular OEM speakers are said to be 15 watts RMS at 4 ohms.
yes they are the right resistance, and maybe they are louder.
but
1. they will distort and|or blow
2. they dont have a seperate tweeter
3. i doubt their timing will play as nice with the front speakers.
$10 at the junkard got me the tweeters on the speakers i wanted, and it was also cheaper than the $40 used speakers on ebay.
if i had the extra money, i would of jst got an amplifier and maybe some peerless drivers with at least a 2-way crossover for the front, and a 3-way crossover with cutouts in the rear doors for the woofer with the midrange and tweeter in the rear deck.
i hear what you are saying about could be dangerous.
nobody needs to be using a resistor on only one speaker terminal.
it makes the amp lop sided and that stress is dumb to say the least.
i didnt agree with the person that said the electricity wouldnt be poised to stay in the voice coil rather than make its way down to another 2 ohms of resistance.
but
it was said that the voice coil gap doesnt offer any place of lesser resistance, which is really jst saying the impedance is a constant.
i still believe the electricity would shy away from going further forward to the other speaker terminal.
amplifiers are for the most part basic, until the equation of the pieces are looked at.
for example..
one amplifier has a rail that pushes the speaker cone from neutral to outwards, with the ability to slowly bring the cone back to neutral without the need of the other rail.
the same amplifier will use the other rail to pull the cone from neutral and slowly move the cone back to neutral.
while another amplifier uses one rail to go forward and the other rail to go backwards regardless of whether the cone position is positive above the neutral spot or negative under the neutral spot.
i figure the only way to make each speaker wire do something for a simple sine wave is to allow each side to output something at the same exact time.
doesnt appear immediately possible without both rails being fully bipolar.
i get that the rail needs to be polarized for the sake of push or pull.
i was trying to get some speaking about each side being bipolar.
perhaps under-utilized.. perhaps under-supported.
see.. this is the THIRD type of amplifier design.
where it was specifically said.. one terminal outputs the full bias while the other terminal simply adds a sink.
the FOURTH type that i was talking about is kinda like this one, except the sink is biased in relation to the other side, thus creating the clamp.
going by the third amp design, i would use a resistor on the positive speaker terminal and not worry about the amplifier seeing something with 2 ohms on one side and 4 ohms on the other rail.
but
with the fourth type, i would need a resistor on both sides again since each side has an input and and output.
(the third amplifier type basically says the red is input and the black is always output.. while the fourth says the red is input as the black is output, but both the red and black terminals are biased for input and output to create the clamp i was talking about)
see..
i knew it made sense that i thought it might ever be possible for 11 watts RMS to be combining from each side to create the full stride of 22 watts.
i find those types of pictures adorable.
it shows what is there, and grants permission to ask what isnt there.
it always helps to see a visual representation of what is there, and what other ways it can be done.
that way you put one picture into a folder, and then each folder can go into the drawer of the file cabinet.
i really want to get a seperate picture for each of the four types of amps i was talking about.
because as long as time is the same across the board, there are improvements of one type over the other.
the downsides to each one can go in the folder.
i mean..
what if the consumer market always shops within the 1,2,3 amp category and doesnt know about category 4 ?
there isnt any market except when somebody comes in the electronics shop to have one built, and since they it can be done .. they might be poised to do it themselves.
that isnt really a customer you want to share energy with unless they've come to the conclusion about being there in the shop.
if they are ready and willing to take their things and walk out the door throughout the whole conversation, i consider that rough treatment.. i consider charging the person full price as difficult.
some people say 'if you are willing to sit down and talk to me about it.. i might charge you less'
and then there are thousands of people saying 'if they can walk in to the shop and keep you busy with your mouth.. you should charge them the same (or more) for taking up your time.'
and then they come to places like this and try to create divides amongst the people when they are trying to gather up information that they might take into an electronics shop.
we are either being made silent and handing our money over to have it done.
or
we are talking about the steps necessary together as there is still some reason the person isnt doing it themselves and has chosen to allow somebody else to do it.
and then they say.. 'chosen to allow isnt the same as chosen to pay'
i figure the cost is for parts and then the labor to assemble those parts.
then the shop owner pays the bills with the labor costs.
it scares me to think spending quality time with people is going to amount to the person paying some money before they walk out the door when both of you are enjoying the same thing.
they say.. you shouldnt make exceptions about your labor costs as if suddenly your labor is less valuable.
and i dont look at it like that.
because if i did, the only option is to say 'i will pay for the premium version of components and charge you the price for the oem version'
if you do that, then the person is going to feel obligated to come back to the shop and talk to you as if you are friends, buddys, aquaintences.. and you cant get work done as fast when you are talking to a friend, buddy, or aquaintence.
to me, it is easier for me to say.. 'hey since you (or the person you talked to before coming here) knows almost as much as i do about building the thing.. i will charge you less for labor and let your scale lean back towards 'i did it myself'
i mean.. if the person has drawn the schematic they want built.. that is at least 25% of the work.
if they buy all the components, then they've done 50% of the work for you.
why charge them 100% when they deserve 50% off?
some say.. well you dont need to draw a schematic when we can simply show you all four amplifier types and jst let you read the pro's and con's and let you point at which one you want.
some say that means they didnt draw the schematic, and i say they still draw the schematic when they point at which one they want IF they read and understood the pro's and con's.
if the schematic counts as 25% .. i dont really go into the details about what the percentage would be if they read pro's and con's from a brochure and chose which one they wanted.
i mean.. the math say the first action is to take 25% and split it in half and jst leave it there since they didnt draw the thing piece by piece.
then it says take that half of 12.5% and cut it in half again because they dont know how each and every single piece goes together.. creating the 6.25%
but
i think if you taught them how 90-98% of the amplifier works (except maybe some diodes or something) then that 6.25% should increase back to what? 12.5% ?
25% of 12.5% = 9.375%
very honestly sad that people dont go back and forth between the 12.5% and 9.375% when offering discounts.
they jst have one concrete price and keep it there unless you take them to court where they are ordered to pay refunds.
society is losing all the essentials that keep the world turning.
it shows what is there, and grants permission to ask what isnt there.
it always helps to see a visual representation of what is there, and what other ways it can be done.
that way you put one picture into a folder, and then each folder can go into the drawer of the file cabinet.
i really want to get a seperate picture for each of the four types of amps i was talking about.
because as long as time is the same across the board, there are improvements of one type over the other.
the downsides to each one can go in the folder.
i mean..
what if the consumer market always shops within the 1,2,3 amp category and doesnt know about category 4 ?
there isnt any market except when somebody comes in the electronics shop to have one built, and since they it can be done .. they might be poised to do it themselves.
that isnt really a customer you want to share energy with unless they've come to the conclusion about being there in the shop.
if they are ready and willing to take their things and walk out the door throughout the whole conversation, i consider that rough treatment.. i consider charging the person full price as difficult.
some people say 'if you are willing to sit down and talk to me about it.. i might charge you less'
and then there are thousands of people saying 'if they can walk in to the shop and keep you busy with your mouth.. you should charge them the same (or more) for taking up your time.'
and then they come to places like this and try to create divides amongst the people when they are trying to gather up information that they might take into an electronics shop.
we are either being made silent and handing our money over to have it done.
or
we are talking about the steps necessary together as there is still some reason the person isnt doing it themselves and has chosen to allow somebody else to do it.
and then they say.. 'chosen to allow isnt the same as chosen to pay'
i figure the cost is for parts and then the labor to assemble those parts.
then the shop owner pays the bills with the labor costs.
it scares me to think spending quality time with people is going to amount to the person paying some money before they walk out the door when both of you are enjoying the same thing.
they say.. you shouldnt make exceptions about your labor costs as if suddenly your labor is less valuable.
and i dont look at it like that.
because if i did, the only option is to say 'i will pay for the premium version of components and charge you the price for the oem version'
if you do that, then the person is going to feel obligated to come back to the shop and talk to you as if you are friends, buddys, aquaintences.. and you cant get work done as fast when you are talking to a friend, buddy, or aquaintence.
to me, it is easier for me to say.. 'hey since you (or the person you talked to before coming here) knows almost as much as i do about building the thing.. i will charge you less for labor and let your scale lean back towards 'i did it myself'
i mean.. if the person has drawn the schematic they want built.. that is at least 25% of the work.
if they buy all the components, then they've done 50% of the work for you.
why charge them 100% when they deserve 50% off?
some say.. well you dont need to draw a schematic when we can simply show you all four amplifier types and jst let you read the pro's and con's and let you point at which one you want.
some say that means they didnt draw the schematic, and i say they still draw the schematic when they point at which one they want IF they read and understood the pro's and con's.
if the schematic counts as 25% .. i dont really go into the details about what the percentage would be if they read pro's and con's from a brochure and chose which one they wanted.
i mean.. the math say the first action is to take 25% and split it in half and jst leave it there since they didnt draw the thing piece by piece.
then it says take that half of 12.5% and cut it in half again because they dont know how each and every single piece goes together.. creating the 6.25%
but
i think if you taught them how 90-98% of the amplifier works (except maybe some diodes or something) then that 6.25% should increase back to what? 12.5% ?
25% of 12.5% = 9.375%
very honestly sad that people dont go back and forth between the 12.5% and 9.375% when offering discounts.
they jst have one concrete price and keep it there unless you take them to court where they are ordered to pay refunds.
society is losing all the essentials that keep the world turning.
I'm holding my breath to see who's going to takcle this one ....
jan
awww.. i see you saying it isnt feasible yet for such a thing, either because it hasnt been made available to the public or because of design flaws (probably from a lack of readily available materials).
**edit**
or maybe you were talking about some amplifier design you own or have designed personally.
Last edited:
Quote:
Originally Posted by Arty
Let me.. ask if i managed to understand correctly:
You would like to know if it is safe to connect a 2 ohm speaker to a cd player that requires 4 ohm load, via a 10 watt 2 ohm resistor.
Yes, it is safe.
But it is inefficient.
Sugested solution was to use 2 speakers in series.
otherwise you loose half of amplifier power wasted as heat.
hi.
i know of the power being wasted to the resistor.
but
look at what i am looking at.
it cost me $10 for those speakers at the junkyard, and the regular OEM speakers are said to be 15 watts RMS at 4 ohms.
yes they are the right resistance, and maybe they are louder.
but
1. they will distort and|or blow
2. they dont have a seperate tweeter
3. i doubt their timing will play as nice with the front speakers.
there is no reason for them to blow.
Why you think anything would blow ?
Originally Posted by Arty
Let me.. ask if i managed to understand correctly:
You would like to know if it is safe to connect a 2 ohm speaker to a cd player that requires 4 ohm load, via a 10 watt 2 ohm resistor.
Yes, it is safe.
But it is inefficient.
Sugested solution was to use 2 speakers in series.
otherwise you loose half of amplifier power wasted as heat.
hi.
i know of the power being wasted to the resistor.
but
look at what i am looking at.
it cost me $10 for those speakers at the junkyard, and the regular OEM speakers are said to be 15 watts RMS at 4 ohms.
yes they are the right resistance, and maybe they are louder.
but
1. they will distort and|or blow
2. they dont have a seperate tweeter
3. i doubt their timing will play as nice with the front speakers.
there is no reason for them to blow.
Why you think anything would blow ?
Quote:
Originally Posted by Arty
Let me.. ask if i managed to understand correctly:
You would like to know if it is safe to connect a 2 ohm speaker to a cd player that requires 4 ohm load, via a 10 watt 2 ohm resistor.
Yes, it is safe.
But it is inefficient.
Sugested solution was to use 2 speakers in series.
otherwise you loose half of amplifier power wasted as heat.
hi.
i know of the power being wasted to the resistor.
but
look at what i am looking at.
it cost me $10 for those speakers at the junkyard, and the regular OEM speakers are said to be 15 watts RMS at 4 ohms.
yes they are the right resistance, and maybe they are louder.
but
1. they will distort and|or blow
2. they dont have a seperate tweeter
3. i doubt their timing will play as nice with the front speakers.
there is no reason for them to blow.
Why you think anything would blow ?
talking about the common ways a speaker's voice coil dies:
1. the heat tolerance goes over the limit, the metal expands and contracts until the metal stops making contact with eachother.
2. the voice coil rubs itself away from non-linear movement because the speaker cone moves in and out beyond the limit (did this with some infinity subwoofers)
3. sometimes there are pieces of ceramic inside the voice coil that either fry away from too much power going directly to them, too much heat surrounding the piece of ceramic, or because the windings expanded and contracted and the piece of ceramic moved and is no longer in the right spot.
4. the glue holding the windings together got hotter than it should of and the windings at the bottom of the coil simply start to fall off (had some windings come apart on a woofer in the house, dunno if it was heat or jst bad glue).
5. the heat causes the windings to expand and contract until the voice coil is out of shape and rubs on the magnet.
i've seen oem speakers die from too much bass, and i've seen them die from with the bass turned down and too much midrange (maybe it was the treble that did it.. not really certain)
speakers blow when they are sitting there for light use.
speakers blow when they get modest use.
there is no intention for them to stay there when the car audio market has all of the product offerings.
99% of the time its the volume knobs fault, either too much bass or too much treble or too much volume being demanded.
Or probably he says this regarding your understanding on amplifiers? What is category 1,2,3 and 4?
Hi,
No. The two halves of an amplifier don't operate independently,
even when you bridge amplifiers, you still only need one resistor.
You never need two, two is the same a doubling one resistor.
If you think otherwise, you thinking is not right.
rgds, sreten.
Try to het your head around that the current goes into one terminal, goes through everything it encounters (speaker, resistor, cabling) and comes out EXACTLY THE SAME at the other end. There is only ONE path.
Amps may be configured with a push-pull stage internally, but for the speaker hanging on the red and black post it's all rock and roll. Just current passing through, back and forth.
If you'd manage that, you'd make a huge step forward.
jan
Nonsense. Remember: there's only ONE path. If you have a 1 amp RMS signal current going through your 2 ohms speaker, the speaker will dissipate 2W power from the amp. I^2*R.
If you add a 2 ohms resistor in series, that resistor will see the SAME 1 amp RMS and being 2 ohms, will also dissipate 2W. Total the amp delivers 4W, half in the speaker and half in the R. Simple, no?
And it makes no fukkie difference whether the R is on the black or red post, or in which order the R and speaker are interconnected, as long as they are in series. Same current, remember? You DID get that, didn't you?
jan
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