Speaker Phasing/Fade Control
06-24-2005, 05:08 AM
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Speaker Phasing/Fade Control
Ok electronic junkies
I'm considering putting addition speakers into the rear of my car but on several previous projects when I did this I had serious problems when I tried to fade from the front speakers to tthe back. When the fade was full to the front no problem at any volume. As I faded to the back, the more I faded the more they would start to distort particularly the louder the volume was set at.
Anybody know what's up with that??
I'm considering putting addition speakers into the rear of my car but on several previous projects when I did this I had serious problems when I tried to fade from the front speakers to tthe back. When the fade was full to the front no problem at any volume. As I faded to the back, the more I faded the more they would start to distort particularly the louder the volume was set at.
Anybody know what's up with that??
06-24-2005, 01:23 PM
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Hmm not sure how to explain or what you you mean by what type.
I never looked that closely. They look like typical car speakers to me. I did two similar projects so far with the same results.
One was a pioneer stereo I put in a Jeep. The stereo had front and rear speaker connections. On the jeep I attached the rear speaker leads to a set of mid speakers and then in paralell to a set of secondary rear speakers that came in one of those pre assembled boom boxes.
The second is my boat. I had similar problems already with the radio that was in her when I go her so I replaced the The alpine has the typical front and rear speaker leads also. I would have to check but I think there is only one set of fronts in the cabin and one set of rear speakers. They appear to be your typical car audio type speakers except with white covers .
What should I be looking for or what info do you need to figure the puzzle out???
I never looked that closely. They look like typical car speakers to me. I did two similar projects so far with the same results.
One was a pioneer stereo I put in a Jeep. The stereo had front and rear speaker connections. On the jeep I attached the rear speaker leads to a set of mid speakers and then in paralell to a set of secondary rear speakers that came in one of those pre assembled boom boxes.
The second is my boat. I had similar problems already with the radio that was in her when I go her so I replaced the The alpine has the typical front and rear speaker leads also. I would have to check but I think there is only one set of fronts in the cabin and one set of rear speakers. They appear to be your typical car audio type speakers except with white covers .
What should I be looking for or what info do you need to figure the puzzle out???
06-25-2005, 09:42 AM
#4
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uh... i don't even know where to being to answer your question... i'm concluding from your questions and past experiences that you have little to know quantitative understanding of this type of electronics, or possibly electronics in general.
so, i'm going to kinda start in the middle. if i'm covering stuff you already know, i'll go up in technical discussions... if you're still lost, i'll have to go down.
essentially, there are specifications and limitations to the equipment you buy and install. power output capabilities (and NOT max power), speaker resistances (impedence), and certain ways to wire things to get these limitations to work with each other.
this happened because you wired up the rear speakers improperly, and were probably overloading the internal amp (asking it to drive too low an impedence load). a standard HU is generally rated for 18 Watts RMS (continuous) or less and is rated to output that power at 4 ohms. if you wired 2 sets of speakers in parallel, you brought that load down to 2 ohms, which i can guarantee you is out of the HU's operating abilities.
regarding distortion getting worse as you increase the volume...
well, amplifiers have a limit on the output they can generate before they reach a ceiling of clean power. once you cross that ceiling, as you turn up the volume, you just add more noise, not more loudness.
if you place additional stress on the amp beyond it's design (ie asking a 4 ohm load capable amp to drive a 2 ohm load), it's going to hit that ceiling sooner. ie, your Jeep.
now, for your S and what you want to do...
can you be a bit more specific on your intent, where you are starting from, where you want to go, and some of what you want to do on the way?
new front speakers? new rears? S-pods? rear panels? budget? OEM head unit? aftermarket HU?
i (and the other EJ's) can coach you through this so you don't have problems, but since we aren't there to judge your understanding, we need this kind of info from you, as well as clear questions.
so, i'm going to kinda start in the middle. if i'm covering stuff you already know, i'll go up in technical discussions... if you're still lost, i'll have to go down.
essentially, there are specifications and limitations to the equipment you buy and install. power output capabilities (and NOT max power), speaker resistances (impedence), and certain ways to wire things to get these limitations to work with each other.
One was a pioneer stereo I put in a Jeep. The stereo had front and rear speaker connections. On the jeep I attached the rear speaker leads to a set of mid speakers and then in paralell to a set of secondary rear speakers that came in one of those pre assembled boom boxes.
regarding distortion getting worse as you increase the volume...
well, amplifiers have a limit on the output they can generate before they reach a ceiling of clean power. once you cross that ceiling, as you turn up the volume, you just add more noise, not more loudness.
if you place additional stress on the amp beyond it's design (ie asking a 4 ohm load capable amp to drive a 2 ohm load), it's going to hit that ceiling sooner. ie, your Jeep.
now, for your S and what you want to do...
can you be a bit more specific on your intent, where you are starting from, where you want to go, and some of what you want to do on the way?
new front speakers? new rears? S-pods? rear panels? budget? OEM head unit? aftermarket HU?
i (and the other EJ's) can coach you through this so you don't have problems, but since we aren't there to judge your understanding, we need this kind of info from you, as well as clear questions.
06-27-2005, 05:29 AM
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Interesting that I have put in lot of csar stereos over th years and never had this problem before but most of those systems were low tech, low powere units. Seems liek all the problems are with newer high powered more sophioscticated equipment. Don't know if tha tis significant or not but. The Jeep is gone so I really can't go look at what all was there but I still have the boat but will have to go to the marina and pull some stuff apart tonight if i get time to see what the how it is actually wired . I am assuming that the speakers are all the same ohmage either 4 or 8 but maybe not. Before I star working on the S I woudl like to fix my floater too and therfore get a little smarter. So basically if you add speakers to a cuircuit if they are in parallell you change the resistance/ohms. What happens if you add them in series?
Also, the boat appears to have been a pretty basic set up. An Alpine stereo supplied from Honda with seperate front and rear speaker leads. I wired up the front 2 speakers to the front leads and the rear two to the rear leads. When you fade to the rear speaker it starts to distort the more you fade the volume. If you put the fade on full front you can crank it up with no problem till eventually it starts to clip. What gives?
Relative to the S eventully I would like to add speakers into the headrest so I can hear something at speed but haven't decided exactly what yet.
Thanks much for the advise.
Also, the boat appears to have been a pretty basic set up. An Alpine stereo supplied from Honda with seperate front and rear speaker leads. I wired up the front 2 speakers to the front leads and the rear two to the rear leads. When you fade to the rear speaker it starts to distort the more you fade the volume. If you put the fade on full front you can crank it up with no problem till eventually it starts to clip. What gives?
Relative to the S eventully I would like to add speakers into the headrest so I can hear something at speed but haven't decided exactly what yet.
Thanks much for the advise.
06-27-2005, 05:43 AM
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More questions please
So if 4 ohms plus 4 ohms in parallell = 2 ohms (what is the math on that?)
and then what does 8 ohms + 8 ohms = ?? 4 ohms??
and if so then what does 8 + 4 ohms = ??
Should you be wiring additional speakers, regardless of resistance in parallel or series? And how do you figure out the resistance implications?
Also if you wire in series doesn't it mess up you + - phasing?
I humbly dumb but a reasonably fast learner!
Thanks again.
So if 4 ohms plus 4 ohms in parallell = 2 ohms (what is the math on that?)
and then what does 8 ohms + 8 ohms = ?? 4 ohms??
and if so then what does 8 + 4 ohms = ??
Should you be wiring additional speakers, regardless of resistance in parallel or series? And how do you figure out the resistance implications?
Also if you wire in series doesn't it mess up you + - phasing?
I humbly dumb but a reasonably fast learner!
Thanks again.
06-27-2005, 09:49 AM
#7
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ok, please don't take this the wrong way. i do not intend to insult or offend you, but just because you did it before and had some success, does not mean it was appropriate. it may mean that you lucked out and didn't damage your equipment.
new technology or old technology and high power or low power, the rules were pretty much the same.
it also may be because you were just replacing OEM equipment w/ upgrades, and generally if you don't change much but individual pieces of equipment w/ upgraded equivalents - the math stays the same and your risk is minimal.
the misconception that you can just 'tie on more speakers' to a system is easily one of the most common and misunderstood concepts in any form of audio. so, don't feel like you've missed something obvious.
this one just about everyone messes up when they're starting to learn.
take a moment, and read up on this page in detail. http://www.bcae1.com/srsparll.htm
you can skip some of the math section if you'd like...
to answer the question though, speakers properly hooked up in series or parallel will have no phase issues. improperly hooked up series or parallel, they will BOTH have phase issues.
then, skip to this page and read it:
http://www.bcae1.com/spkrmlti.htm
pay special attention to the 'lame water pump analogy' at the bottom and the 'Calculating Series and Parallel Resistance' section.
ok -- done w/ that?
so, when wired in series, resistors (speakers) are added together. R1+R2+R3+R4+....
when in parallel, resistors are added as the reciprocal of the sum of reciprocals. 1/Rt = 1/R1 + 1/R2 + 1/R3 + 1/R4 + ....
in your case, if you have 3 speakers at 4 ohms each, you add them as such. 1/4 + 1/4 + 1/4 = 3/4. Rt = 4/3 = 1.33 ohms
those same speakers in series are 4 + 4 + 4 = 12 ohms
very very different loads.
now, if you have an 8 ohm speaker and a 4 ohm speaker, the math goes as such:
parallel: 1/8 + 1/4 = 1/8 + 2/8 = 3/8 Rt = 8/3 = 2.67 ohms
series: 8 + 4 = 12 ohms
now -- here's the kicker. generally speaking, an amp is stupid. whether it's an outboard amp or a head unit amplifier. the power it attempts to output is determined by the resistance it sees (ie pump analogy). if you put too much resistance in place, it is generally ok, but it outputs very little power and sounds quiet. however, if the resistance is too low, it will attempt to output WAY too much (current) power and will burn itself up in trying. hopefully, it will either blow a fuse or power down from heat before dying. but it's not guaranteed.
now regarding distortion... you mentioned clipping above, but based on the reference, i'm not sure you understand what clipping distortion is...
there are 2 primary types of distortion out there.
mechanical and clipping.
-mechanical is what happens when you reach the limitations of the speaker. the sound will distort, the speaker will make funny noises, it could be popping or a nasty smacking sound, or other such signs... this will always happen from too much power to the speaker. this is the most commonly noticed and recognized distortion. when you're here, chances are you're damaging your speakers, or are starting to work on it...
-clipping distortion isn't as easily detected. to understand clipping distortion, you've got to understand how amps work. when i stated above, "well, amplifiers have a limit on the output they can generate before they reach a ceiling of clean power. once you cross that ceiling, as you turn up the volume, you just add more noise, not more loudness.", i was talking about clipping distortion.
to help you better visualize it, your amp has an ability to provide X amount of power. that limit is the amp's ceiling. when you begin to clip, the requested power from the amp exceeds the ceiling, so the amp just gives you the ceiling (all it can). but the ceiling isn't the original signal, it's a 'clipped' signal. thus, it doesn't sound right. it will sound all warbled and blurry. that is clipping distortion... and often, that distortion is nothing like the mechanical distortion you hear.
-mechanical and clipping distortion can come individually or simultaneously, they are not exclusive.
ok, now that i've defined distortion -- we can look at the scenario of your boat. the rears distort sooner than the fronts. is it clipping or mechanical distortion? that will help tell you what's going on.
there are a number of possible things going on here:
one possible (and very likely scenario) is that the power handling of the front and rear speakers are different. so, you're mechanically distorting the rears first because they are designed to handle less power.
another possible scenario is that they could be different resistances (impedances), which means they are actually receiving different amounts of power (front to back). you could be within the amplifier's rated range, but are mechanically distorting the rears first. (this could happen if you have 8 ohm fronts and 4 ohm rears)
yet another possible scenario is you could be clipping the amplifier on the backs and causing distortion because the rears are wired differently than the fronts or are a load outside (below) the amplifier's rated load.
why an Alpine from Honda? is this some sort of Honda radio from a car??
also, you mention they 'clip' are you talking clipping distortion or are they cutting out?
if you're really interested in learning more -- this page: http://www.bcae1.com/installationprimer.htm
is a great place to start. it's a primer for basic installation, and it covers a lot of general misinformation, myths, and commonly misunderstood things.
hopefully some of this helps. as you can (hopefully) see, there are a lot of factors that need to be accounted for when setting something up.
new technology or old technology and high power or low power, the rules were pretty much the same.
it also may be because you were just replacing OEM equipment w/ upgrades, and generally if you don't change much but individual pieces of equipment w/ upgraded equivalents - the math stays the same and your risk is minimal.
the misconception that you can just 'tie on more speakers' to a system is easily one of the most common and misunderstood concepts in any form of audio. so, don't feel like you've missed something obvious.
this one just about everyone messes up when they're starting to learn.take a moment, and read up on this page in detail. http://www.bcae1.com/srsparll.htm
you can skip some of the math section if you'd like...
to answer the question though, speakers properly hooked up in series or parallel will have no phase issues. improperly hooked up series or parallel, they will BOTH have phase issues.
then, skip to this page and read it:
http://www.bcae1.com/spkrmlti.htm
pay special attention to the 'lame water pump analogy' at the bottom and the 'Calculating Series and Parallel Resistance' section.
ok -- done w/ that?
so, when wired in series, resistors (speakers) are added together. R1+R2+R3+R4+....
when in parallel, resistors are added as the reciprocal of the sum of reciprocals. 1/Rt = 1/R1 + 1/R2 + 1/R3 + 1/R4 + ....
in your case, if you have 3 speakers at 4 ohms each, you add them as such. 1/4 + 1/4 + 1/4 = 3/4. Rt = 4/3 = 1.33 ohms
those same speakers in series are 4 + 4 + 4 = 12 ohms
very very different loads.
now, if you have an 8 ohm speaker and a 4 ohm speaker, the math goes as such:
parallel: 1/8 + 1/4 = 1/8 + 2/8 = 3/8 Rt = 8/3 = 2.67 ohms
series: 8 + 4 = 12 ohms
now -- here's the kicker. generally speaking, an amp is stupid. whether it's an outboard amp or a head unit amplifier. the power it attempts to output is determined by the resistance it sees (ie pump analogy). if you put too much resistance in place, it is generally ok, but it outputs very little power and sounds quiet. however, if the resistance is too low, it will attempt to output WAY too much (current) power and will burn itself up in trying. hopefully, it will either blow a fuse or power down from heat before dying. but it's not guaranteed.
now regarding distortion... you mentioned clipping above, but based on the reference, i'm not sure you understand what clipping distortion is...
there are 2 primary types of distortion out there.
mechanical and clipping.
-mechanical is what happens when you reach the limitations of the speaker. the sound will distort, the speaker will make funny noises, it could be popping or a nasty smacking sound, or other such signs... this will always happen from too much power to the speaker. this is the most commonly noticed and recognized distortion. when you're here, chances are you're damaging your speakers, or are starting to work on it...
-clipping distortion isn't as easily detected. to understand clipping distortion, you've got to understand how amps work. when i stated above, "well, amplifiers have a limit on the output they can generate before they reach a ceiling of clean power. once you cross that ceiling, as you turn up the volume, you just add more noise, not more loudness.", i was talking about clipping distortion.
to help you better visualize it, your amp has an ability to provide X amount of power. that limit is the amp's ceiling. when you begin to clip, the requested power from the amp exceeds the ceiling, so the amp just gives you the ceiling (all it can). but the ceiling isn't the original signal, it's a 'clipped' signal. thus, it doesn't sound right. it will sound all warbled and blurry. that is clipping distortion... and often, that distortion is nothing like the mechanical distortion you hear.
-mechanical and clipping distortion can come individually or simultaneously, they are not exclusive.
ok, now that i've defined distortion -- we can look at the scenario of your boat. the rears distort sooner than the fronts. is it clipping or mechanical distortion? that will help tell you what's going on.
there are a number of possible things going on here:
one possible (and very likely scenario) is that the power handling of the front and rear speakers are different. so, you're mechanically distorting the rears first because they are designed to handle less power.
another possible scenario is that they could be different resistances (impedances), which means they are actually receiving different amounts of power (front to back). you could be within the amplifier's rated range, but are mechanically distorting the rears first. (this could happen if you have 8 ohm fronts and 4 ohm rears)
yet another possible scenario is you could be clipping the amplifier on the backs and causing distortion because the rears are wired differently than the fronts or are a load outside (below) the amplifier's rated load.
An Alpine stereo supplied from Honda with seperate front and rear speaker leads.
also, you mention they 'clip' are you talking clipping distortion or are they cutting out?
if you're really interested in learning more -- this page: http://www.bcae1.com/installationprimer.htm
is a great place to start. it's a primer for basic installation, and it covers a lot of general misinformation, myths, and commonly misunderstood things.
hopefully some of this helps. as you can (hopefully) see, there are a lot of factors that need to be accounted for when setting something up.
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06-27-2005, 01:15 PM
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My head is spinning!!!!!!! Lots to read tonight!
I will get back to you after my crash course.
PS . I always understood clipping as cutting off the peaks of sound waves due to inadequate power to reproduce them but I probalby would not be able to differentiate the audible difference between that and mechanical speaker breakdown.
Thanks again for the crash course.
I will get back to you after my crash course.
PS . I always understood clipping as cutting off the peaks of sound waves due to inadequate power to reproduce them but I probalby would not be able to differentiate the audible difference between that and mechanical speaker breakdown.
Thanks again for the crash course.
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