Auto up/down
04-18-2002, 07:19 PM
#1
Three Wheelin'
Thread Starter
Auto up/down
I just threw some Polks in the front doors temporarily until I get some components and an amp. Anyhow, I just noticed that the auto up/down on the driver's side does not work. All lights, windows, mirrors and locks work fine so I'm fairly sure I hooked everything back up properly. Anyone have any ideas what I should look for when I tear the panel off again?
When I took the panel off I did not disconnect the battery, but the ignition was off if that matters at all.
Thanks in advance,
Iggy
ps. Southbound, you were right. It does sound a whole lot better,
But I WANT MORE!
When I took the panel off I did not disconnect the battery, but the ignition was off if that matters at all.
Thanks in advance,
Iggy
ps. Southbound, you were right. It does sound a whole lot better,
But I WANT MORE!
04-19-2002, 01:19 AM
#2
Pro
Join Date: Feb 2002
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
check them again...
Iggy,
Sorry to hear about your problem. I didn't disconnect my battery either, just had the key out, and I didn't have any problems. I did notice, that the passenger window wouldn't roll up or down even from the driver side switches with the passenger door panel off. I was trying to roll it down to check for clearances, etc. while I was in the install process. So somehow all of the window wiring loops together through BOTH doors. All I can say, is check all of the connectors again on BOTH doors. Remove them and reinsert them. One might not be fully inserted or somehow crooked. Did they all release easily? IF not, perhaps a pin got bent or broken during the process???
You might check the fuses first. I wouldn't think that there would be a separate fuse for just the "auto" part of the electric windows. But who knows? Sorry to hear about that...
So what are your future plans. I'd probably bypass the EQ and add an amp before I'd change out the Polk DX6s for components. See what you get once you do that and give us a report. Then you could put the DX6s in the rear and upgrade to components up front if it's still not enough...
Sorry to hear about your problem. I didn't disconnect my battery either, just had the key out, and I didn't have any problems. I did notice, that the passenger window wouldn't roll up or down even from the driver side switches with the passenger door panel off. I was trying to roll it down to check for clearances, etc. while I was in the install process. So somehow all of the window wiring loops together through BOTH doors. All I can say, is check all of the connectors again on BOTH doors. Remove them and reinsert them. One might not be fully inserted or somehow crooked. Did they all release easily? IF not, perhaps a pin got bent or broken during the process???
You might check the fuses first. I wouldn't think that there would be a separate fuse for just the "auto" part of the electric windows. But who knows? Sorry to hear about that...
So what are your future plans. I'd probably bypass the EQ and add an amp before I'd change out the Polk DX6s for components. See what you get once you do that and give us a report. Then you could put the DX6s in the rear and upgrade to components up front if it's still not enough...
04-19-2002, 01:33 AM
#3
Three Wheelin'
The fix for the auto Up/Down is simple: Press and hold down the button and dont release it until the window is all the way down. then release the button. Next, press and hold the button in the up position and dont let go until the window gets to the top. This resets the limiter on the switch. Trust me, this works because i had the same problem on my car after taking the panels off and i thought i screwed something up in the process until someone else on these boards told me the 'fix'.
04-19-2002, 01:44 AM
#4
Pro
Join Date: Feb 2002
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
When in doubt...
Yeah, when in doubt, read the manual...
I just went out and got my manual to check what fuses might be involved... READ PAGE 102 OF YOUR MANUAL! Just like 2002AcuraTL says, It talks about the power windows needing to be reset after disconnecting the battery or replacing a fuse. They may also need to be reset after pulling the connector loose. ALTHOUGH I DIDN'T HAVE TO RESET MINE AFTER TAKING MY PANEL OFF???
If this reset procedure doesn't work, check for the fuse. The ones for the power windows are all under the passenger side kick panel. Hope this is all that is wrong...
I just went out and got my manual to check what fuses might be involved... READ PAGE 102 OF YOUR MANUAL! Just like 2002AcuraTL says, It talks about the power windows needing to be reset after disconnecting the battery or replacing a fuse. They may also need to be reset after pulling the connector loose. ALTHOUGH I DIDN'T HAVE TO RESET MINE AFTER TAKING MY PANEL OFF???
If this reset procedure doesn't work, check for the fuse. The ones for the power windows are all under the passenger side kick panel. Hope this is all that is wrong...
04-19-2002, 01:52 AM
#5
Pro
Join Date: Feb 2002
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
Keep us posted...
Hey Iggy,
keep us posted as to what you find out. If what 2002AcuraTL says is correct in that it is resetting the switch limits, it could explain why some have the problem and others don't. It would probably depend upon what position you had the window set to when you disconnected the connector. Mine was ALL the way UP when I removed and replaced my connectors, and it didn't need reset. Perhaps your window was down when you pulled off the connectors???? That could explain the difference between our situations.
Southbound... P.S. Thanks 2002AcuraTL
keep us posted as to what you find out. If what 2002AcuraTL says is correct in that it is resetting the switch limits, it could explain why some have the problem and others don't. It would probably depend upon what position you had the window set to when you disconnected the connector. Mine was ALL the way UP when I removed and replaced my connectors, and it didn't need reset. Perhaps your window was down when you pulled off the connectors???? That could explain the difference between our situations.
Southbound... P.S. Thanks 2002AcuraTL
04-19-2002, 09:04 AM
#6
Three Wheelin'
Thread Starter
Originally posted by 2002acuraTL
The fix for the auto Up/Down is simple: Press and hold down the button and dont release it until the window is all the way down. then release the button. Next, press and hold the button in the up position and dont let go until the window gets to the top. This resets the limiter on the switch. Trust me, this works because i had the same problem on my car after taking the panels off and i thought i screwed something up in the process until someone else on these boards told me the 'fix'.
The fix for the auto Up/Down is simple: Press and hold down the button and dont release it until the window is all the way down. then release the button. Next, press and hold the button in the up position and dont let go until the window gets to the top. This resets the limiter on the switch. Trust me, this works because i had the same problem on my car after taking the panels off and i thought i screwed something up in the process until someone else on these boards told me the 'fix'.
2002,
Thanks man, It worked like a charm!
You know, it's kinda funny. I've been hanging around on this forum for a while now and always kinda chuckled to myself when someone would post a question that was obviously in the manual. Now, I'm the guy who did the same thing without even thinking about it
. oh well, I guess that's why were all here. Thanks again all yous guys!!!BTW Southbound,
I too had the window fully closed during the install. Go figure
Iggy
04-19-2002, 10:09 AM
#7
Three Wheelin'
Thread Starter
Southbound,
I think what I'll be doing is this:
JL XR650CS components in front
POlk DX6 rear
Earthquake TNT600
...Maximum output power: 600Watts
... Output Power: 65Watts RMSx4 into 4 Ohms
... Bridged Output Power (2Ch): 200Watts RMSx2 into 4 Ohms
... Distortion: 0.015% THD
... Frequency Response: 10Hz-35kHz +/- 1.5 dB
... Signal To Noise: 104 dB
... High Level Input: 3V-7V
... Low Level Input: 200mV-4V
... Size(WxHxD): 8 1/2" x 2" x 12"
bypass factory EQ
4 guage off battery to allow for future sub amp
16 guage to all doors
The only things I'm still undecided on are where to put the tweeters, and if I should take line level signal off the HU(in which case I would lose fading control) or 4ch LOC off speaker outs(in which case I retain fading control but lose a little signal quality going into amp)
Anyhow,
That's it in general. Any thoughts you guys/gals?
See ya,
Iggy
I think what I'll be doing is this:
JL XR650CS components in front
POlk DX6 rear
Earthquake TNT600
...Maximum output power: 600Watts
... Output Power: 65Watts RMSx4 into 4 Ohms
... Bridged Output Power (2Ch): 200Watts RMSx2 into 4 Ohms
... Distortion: 0.015% THD
... Frequency Response: 10Hz-35kHz +/- 1.5 dB
... Signal To Noise: 104 dB
... High Level Input: 3V-7V
... Low Level Input: 200mV-4V
... Size(WxHxD): 8 1/2" x 2" x 12"
bypass factory EQ
4 guage off battery to allow for future sub amp
16 guage to all doors
The only things I'm still undecided on are where to put the tweeters, and if I should take line level signal off the HU(in which case I would lose fading control) or 4ch LOC off speaker outs(in which case I retain fading control but lose a little signal quality going into amp)
Anyhow,
That's it in general. Any thoughts you guys/gals?
See ya,
Iggy
Trending Topics
04-19-2002, 08:25 PM
#10
Three Wheelin'
Thread Starter
Originally posted by 2002acuraTL
no module needed. 2002+ acura TL comes with the auto up feature for drivers side window.
no module needed. 2002+ acura TL comes with the auto up feature for drivers side window.
Like 2002 said,
It's a 2002 thing. we have auto up/down stock.
Cheers,
Iggy
04-20-2002, 03:42 AM
#11
Pro
Join Date: Feb 2002
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
Good plan...
Hey Iggy,
Thanks for the report on the auto up/down gag.
I don't know why it didn't affect me? At least it's an easy fix.
Sounds like you have a GOOD plan. I'm envious of the ambition. It should sound really nice when you are done.
I'd probably mount the tweeters on the sail panels up at the window. I'd mount them there with tape or something first without drilling any holes and listen to them for a few days. If you like the location, THEN mount them permanently. You could probably always buy replacement sail panels in the event that you wanted to move things later. Or just leave the tweeters there disconected for aesthetic purposes only. Some have mounted the tweeters in the door panel. But, Id hate to cut a hole in that... but just have a long wire on the tweeter at first so that you can temporarily move it around and see where it really sounds the best before drilling holes. It seems to me that if it is DOWN in the door, it wouldn't really provide much more benefit than a coaxial speaker... Also, be prepared to do some more mod work to your front door frame. You will need a custom larger spacer with those speakers, and possibly need to cut out the door frame a bit more?
Sounds like you do know what you are doing though. Like you say, in theory it would be best to use the line outputs of the head unit. They would typically be a class A biased preamp stage fed from a down regulated power supply with far less distortion than the pushpull speaker output stage. HOWEVER, It will be a higher impedance output signal and therefore more prone to pick up alternator noise, ignition noise, crosstalk, etc. ESPECIALLY if you have a long run back to the trunk. If you use the line level outputs BE SURE to use shielded cable for that. Also, as you stated, you will lose the fader option... If you use the speaker outputs, DO NOT use shielded cable for the run to the new amp. USE A TWISTED PAIR! Low impedance Speaker output stages cannot handle the reactive phase shift caused by the capacitance of a shielded cable and can become unstable. If they are actually driving a speaker load through this shielded cable, they can see a much lower impedance than they were designed to handle and self destruct. HOWEVER, you will be feeding a high impedance input of another power amp or LOC, so this problem is not as critical. STILL I would use a twisted pair of wires feeding anything from the speaker level output of an amp. The output stage of a speaker level amp is VERY LOW IMPEDANCE... typically .1 ohm or there abouts. (That is the only way it could drive a 2 or 4 ohm load without dropping all of the power supply voltage across the output devices.) THEREFORE, the speaker level output is not nearly as suseptable to picking up crosstalk, etc. Again, since it is feeding a high impedance input of another amp or LOC, it wouldn't be working very hard and wouldn't be driven up into its built in limiting or clipping range. Therefore, its inherent distortion would be less than what you hear now when it is driving a speaker. My guess is that the crappiest part of the stock system is in the automatic EQ circuit. I've read the BOSE website about the system and it's supposedly doing a lot of favors that we don't want! There is also some signal processing and limiting going on in the amplifier section which does protect the speakers from fully clipped signals. You do not want to have to push the gain of the head unit amp up into this range before it is sufficient to drive the new amp or you will be hearing compression and limiting distortion before you need it.
The high level input signal level requirements of your new amp are stated as 3-7 volts. I assume this is rms. That being the case, here is what you could expect as a voltage level output of the stock head unit. We know that the power supply for the stock head unit output stage is only 12 volts, (even though it's actually around 13.8 volts with the engine/alternator running.) That means that the most the output stage could swing would be 12 volts peak to peak. They would bias the output stage to +6 volts and let it swing up to +12 volts and down to ground before clipping. They would use a large capacitor to couple the signal out to the speaker to keep the 6 volts DC off of the speaker. This leaves you with a 6 volt "peak" voltage signal. I'm sure you know, but just for the sake of others who may not know. RMS stands for "root mean square" It means the square root of the sum of the squares of all voltage levels in the signal through its entire 360 degree cycle. I could show you the math, but for a sinewave it turns out to be the sine of 45 degrees or the inverse of the square root of 2, OR SIMPLY .707 TIMES THE PEAK VALUE OF THE SIGNAL. This means that before a "single ended" amp, fed from a 12 volt power supply, would clip the signal peaks off, the rms voltage level would be .707 times 6 volts or only 4.242 volts RMS! To get the true RMS power into 4 ohms for ANY amplifier in this configuration fed from 12volts, simply square the rms voltage and divide it by the resistance. 4.242 times 4.242(volts) divided by 4 (ohms) gives you a whopping 4.498 WATTS RMS! And RMS power rated into the actual load that you are using is the only rating that means anything. RMS is the mathmatical power that is required for continuous output over more than one cycle. So unless you are only listening to ONE cycle of music, The peak power rating doesn't mean jack! EVERYTHING else is just hype and ways to fake or exaggerate ratings...
To get more than that amount of true continuous rms power... you need to either have a larger power supply voltage or drive lower impedance loads, (such as the 1 and 2 ohm speaker loads that some BOSE amps drive, although I'm sure they sound like crap trying to remain stable while driving that low of an impedance. OR THERE IS ONE COMMON TECHNIQUE that can be used in the design to quadruple the output power of a single ended amp. IT IS VERY COMMON PRACTICE TO DESIGN TWO PUSHPULL OUTPUT STAGES PER CHANNEL, INVERT ONE OF THEM AND DRIVE THEM 180 DEGREES OUT OF PHASE. THEN, FLOAT THE SPEAKERS FROM GROUND AND DRIVE THEM ACROSS THE RESPECTIVE OUTPUTS OF THESE TWO PUSHPULL OUTPUT STAGES... THIS IS A "BRIDGED" OUTPUT... What it allows the speaker to see is TWICE the voltage swing. I'M SURE THIS IS WHAT THE STOCK HEAD UNIT IS DOING. Other higher powered after market amps need to "chop" the DC and create a switching power supply with step up toroidal transmformers in order to work with a higher power supply voltage. Then they, too, use the bridged output technique for further power gain.
Stay with me here, I know I'm crazy, but I'm on a roll... SO NOW WE HAVE A BRIDGED OUTPUT THAT CAN SWING THE EQUIVALENT OF 24 VOLTS PEAK TO PEAK, OR 12 VOLTS PEAK, OR 8.484 VOLTS RMS... So with this type of amplifier configuration, the output signal from a 12 volt power supply could actually produce 8.484 volts rms before clipping. The actual voltage level into a low impedance speaker would be somewhat less, as this assumes 100% effeciency. There would be some voltage drop across the transistor output devices that would make this number a bit lower when actually measured at the speaker. However, when feeding a high impedance load like another amplifier input or a LOC, (typically around 1K-10K ohms) there should be little or no drop across the output devices due to the lack of current demand. So in your case our head units would probably put out a clean signal up to 8 volts rms. (It would be up to over 9 volts in the real world with our alternator supply voltage of 13.8 volts). Above that voltage level, I would expect to see the output limiting circuit start to kick in and compress the signal as well as round off the corners of square waves and fast rise times. The slew rate would diminish rapidly at this point as well. SO, if you fed the high level inputs of the new amp from our speaker level outputs You should be OK. There has to be some voltage gain in the new amp as well as power gain. The new amp wants to see 3-7 volts,(rms?). That typcically means that above 7 volts, the output stage of it will be into clipping. Our head unit should be able to provide 8-9volts rms before it goes into clipping and this is what you want to see. You want to see the final amp clip before any preceeding amp clips. You could feed the low level inputs as well from the stock speaker amp, but you'd find yourself driving the new amp into clipping at a fraction of the volume control on the head unit. These sound like standard input values based upon a standard 12 volt bridged stock head unit, so you should be OK either way you go. BUT, While we're at it, its worth mentioning that in this "bridged" configuration with a 12 volt supply, the stock head unit is now capable of producing a power output of (.707 times 12 volts peak, equals 8.484 volts rms times 8.484 volts divided by 4 ohms, equals 17.99 WATTS RMS! Again that assumes 100% effeciency. It would be a bit more with the 13.8 volt alternator power supply, but with the effeciency loss, this is probably a fairly acurate number. (OUT OF BANDWIDTH, PART TWO TO CONTINUE...)
Thanks for the report on the auto up/down gag.
I don't know why it didn't affect me? At least it's an easy fix.
Sounds like you have a GOOD plan. I'm envious of the ambition. It should sound really nice when you are done.
I'd probably mount the tweeters on the sail panels up at the window. I'd mount them there with tape or something first without drilling any holes and listen to them for a few days. If you like the location, THEN mount them permanently. You could probably always buy replacement sail panels in the event that you wanted to move things later. Or just leave the tweeters there disconected for aesthetic purposes only. Some have mounted the tweeters in the door panel. But, Id hate to cut a hole in that... but just have a long wire on the tweeter at first so that you can temporarily move it around and see where it really sounds the best before drilling holes. It seems to me that if it is DOWN in the door, it wouldn't really provide much more benefit than a coaxial speaker... Also, be prepared to do some more mod work to your front door frame. You will need a custom larger spacer with those speakers, and possibly need to cut out the door frame a bit more?
Sounds like you do know what you are doing though. Like you say, in theory it would be best to use the line outputs of the head unit. They would typically be a class A biased preamp stage fed from a down regulated power supply with far less distortion than the pushpull speaker output stage. HOWEVER, It will be a higher impedance output signal and therefore more prone to pick up alternator noise, ignition noise, crosstalk, etc. ESPECIALLY if you have a long run back to the trunk. If you use the line level outputs BE SURE to use shielded cable for that. Also, as you stated, you will lose the fader option... If you use the speaker outputs, DO NOT use shielded cable for the run to the new amp. USE A TWISTED PAIR! Low impedance Speaker output stages cannot handle the reactive phase shift caused by the capacitance of a shielded cable and can become unstable. If they are actually driving a speaker load through this shielded cable, they can see a much lower impedance than they were designed to handle and self destruct. HOWEVER, you will be feeding a high impedance input of another power amp or LOC, so this problem is not as critical. STILL I would use a twisted pair of wires feeding anything from the speaker level output of an amp. The output stage of a speaker level amp is VERY LOW IMPEDANCE... typically .1 ohm or there abouts. (That is the only way it could drive a 2 or 4 ohm load without dropping all of the power supply voltage across the output devices.) THEREFORE, the speaker level output is not nearly as suseptable to picking up crosstalk, etc. Again, since it is feeding a high impedance input of another amp or LOC, it wouldn't be working very hard and wouldn't be driven up into its built in limiting or clipping range. Therefore, its inherent distortion would be less than what you hear now when it is driving a speaker. My guess is that the crappiest part of the stock system is in the automatic EQ circuit. I've read the BOSE website about the system and it's supposedly doing a lot of favors that we don't want! There is also some signal processing and limiting going on in the amplifier section which does protect the speakers from fully clipped signals. You do not want to have to push the gain of the head unit amp up into this range before it is sufficient to drive the new amp or you will be hearing compression and limiting distortion before you need it.
The high level input signal level requirements of your new amp are stated as 3-7 volts. I assume this is rms. That being the case, here is what you could expect as a voltage level output of the stock head unit. We know that the power supply for the stock head unit output stage is only 12 volts, (even though it's actually around 13.8 volts with the engine/alternator running.) That means that the most the output stage could swing would be 12 volts peak to peak. They would bias the output stage to +6 volts and let it swing up to +12 volts and down to ground before clipping. They would use a large capacitor to couple the signal out to the speaker to keep the 6 volts DC off of the speaker. This leaves you with a 6 volt "peak" voltage signal. I'm sure you know, but just for the sake of others who may not know. RMS stands for "root mean square" It means the square root of the sum of the squares of all voltage levels in the signal through its entire 360 degree cycle. I could show you the math, but for a sinewave it turns out to be the sine of 45 degrees or the inverse of the square root of 2, OR SIMPLY .707 TIMES THE PEAK VALUE OF THE SIGNAL. This means that before a "single ended" amp, fed from a 12 volt power supply, would clip the signal peaks off, the rms voltage level would be .707 times 6 volts or only 4.242 volts RMS! To get the true RMS power into 4 ohms for ANY amplifier in this configuration fed from 12volts, simply square the rms voltage and divide it by the resistance. 4.242 times 4.242(volts) divided by 4 (ohms) gives you a whopping 4.498 WATTS RMS! And RMS power rated into the actual load that you are using is the only rating that means anything. RMS is the mathmatical power that is required for continuous output over more than one cycle. So unless you are only listening to ONE cycle of music, The peak power rating doesn't mean jack! EVERYTHING else is just hype and ways to fake or exaggerate ratings...
To get more than that amount of true continuous rms power... you need to either have a larger power supply voltage or drive lower impedance loads, (such as the 1 and 2 ohm speaker loads that some BOSE amps drive, although I'm sure they sound like crap trying to remain stable while driving that low of an impedance. OR THERE IS ONE COMMON TECHNIQUE that can be used in the design to quadruple the output power of a single ended amp. IT IS VERY COMMON PRACTICE TO DESIGN TWO PUSHPULL OUTPUT STAGES PER CHANNEL, INVERT ONE OF THEM AND DRIVE THEM 180 DEGREES OUT OF PHASE. THEN, FLOAT THE SPEAKERS FROM GROUND AND DRIVE THEM ACROSS THE RESPECTIVE OUTPUTS OF THESE TWO PUSHPULL OUTPUT STAGES... THIS IS A "BRIDGED" OUTPUT... What it allows the speaker to see is TWICE the voltage swing. I'M SURE THIS IS WHAT THE STOCK HEAD UNIT IS DOING. Other higher powered after market amps need to "chop" the DC and create a switching power supply with step up toroidal transmformers in order to work with a higher power supply voltage. Then they, too, use the bridged output technique for further power gain.
Stay with me here, I know I'm crazy, but I'm on a roll... SO NOW WE HAVE A BRIDGED OUTPUT THAT CAN SWING THE EQUIVALENT OF 24 VOLTS PEAK TO PEAK, OR 12 VOLTS PEAK, OR 8.484 VOLTS RMS... So with this type of amplifier configuration, the output signal from a 12 volt power supply could actually produce 8.484 volts rms before clipping. The actual voltage level into a low impedance speaker would be somewhat less, as this assumes 100% effeciency. There would be some voltage drop across the transistor output devices that would make this number a bit lower when actually measured at the speaker. However, when feeding a high impedance load like another amplifier input or a LOC, (typically around 1K-10K ohms) there should be little or no drop across the output devices due to the lack of current demand. So in your case our head units would probably put out a clean signal up to 8 volts rms. (It would be up to over 9 volts in the real world with our alternator supply voltage of 13.8 volts). Above that voltage level, I would expect to see the output limiting circuit start to kick in and compress the signal as well as round off the corners of square waves and fast rise times. The slew rate would diminish rapidly at this point as well. SO, if you fed the high level inputs of the new amp from our speaker level outputs You should be OK. There has to be some voltage gain in the new amp as well as power gain. The new amp wants to see 3-7 volts,(rms?). That typcically means that above 7 volts, the output stage of it will be into clipping. Our head unit should be able to provide 8-9volts rms before it goes into clipping and this is what you want to see. You want to see the final amp clip before any preceeding amp clips. You could feed the low level inputs as well from the stock speaker amp, but you'd find yourself driving the new amp into clipping at a fraction of the volume control on the head unit. These sound like standard input values based upon a standard 12 volt bridged stock head unit, so you should be OK either way you go. BUT, While we're at it, its worth mentioning that in this "bridged" configuration with a 12 volt supply, the stock head unit is now capable of producing a power output of (.707 times 12 volts peak, equals 8.484 volts rms times 8.484 volts divided by 4 ohms, equals 17.99 WATTS RMS! Again that assumes 100% effeciency. It would be a bit more with the 13.8 volt alternator power supply, but with the effeciency loss, this is probably a fairly acurate number. (OUT OF BANDWIDTH, PART TWO TO CONTINUE...)
04-20-2002, 03:47 AM
#12
Pro
Join Date: Feb 2002
Posts: 698
Likes: 0
Received 0 Likes
on
0 Posts
Good Plan, part two continued...
Sorry for my rambles. I swear that I'm always just going to write a paragraph and I end up writing a friggin' journal... Somebody stop me!
SO THE STOCK HEAD UNIT PUTS OUT SOMEWHERE AROUND 18 WATTS RMS INTO 4 OHMS... While this sounds like crap, and it is... REMEMBER, DOUBLING THE OUTPUT POWER WILL ONLY PRODUCE 3DB MORE SPL. So to go from a 20 watt amp to an 80 watt amp (expressed in the same way, i.e., rms into 4ohms) you will only gain 6db more sound pressure level. However, that 6db could be just enough to make the difference, and it would allow the output stage to stay out of limiting and distortion down at the levels where our current head unit now clips and distorts. Plus the general distortion, slew rate and damping factor figures of the new amp would most likely be far superior to the stock amp.
Whew! I hope some of this rap made sense and helped to clarify some issues. If you didn't stay with me, I'm not offended. I guess I am nuts! Probably nobody cares? I'm just here to help where I can. I'm not trying to be a know-it-all... Honest.
So Iggy, there you have the pros and cons of using the line level or speaker level outputs. I'm sure that either method will greatly improve the stock stystem. If you are striving for perfection, though, then I'd somehow try both methods and see which sounds the best. Who knows how crappy the speaker output stage of the stock head unit truly sounds? (and in effect you don't need it to drive the new amp, except for fader controls, and the above mentioned noise immunity/ground loop issues.) You might not be able to tell the difference with it in circuit or bypassed... Maybe others on the board can tell you which way is the typical way to go and which way has worked best for them.
GOOD LUCK! Southbound
SO THE STOCK HEAD UNIT PUTS OUT SOMEWHERE AROUND 18 WATTS RMS INTO 4 OHMS... While this sounds like crap, and it is... REMEMBER, DOUBLING THE OUTPUT POWER WILL ONLY PRODUCE 3DB MORE SPL. So to go from a 20 watt amp to an 80 watt amp (expressed in the same way, i.e., rms into 4ohms) you will only gain 6db more sound pressure level. However, that 6db could be just enough to make the difference, and it would allow the output stage to stay out of limiting and distortion down at the levels where our current head unit now clips and distorts. Plus the general distortion, slew rate and damping factor figures of the new amp would most likely be far superior to the stock amp.
Whew! I hope some of this rap made sense and helped to clarify some issues. If you didn't stay with me, I'm not offended. I guess I am nuts! Probably nobody cares? I'm just here to help where I can. I'm not trying to be a know-it-all... Honest.
So Iggy, there you have the pros and cons of using the line level or speaker level outputs. I'm sure that either method will greatly improve the stock stystem. If you are striving for perfection, though, then I'd somehow try both methods and see which sounds the best. Who knows how crappy the speaker output stage of the stock head unit truly sounds? (and in effect you don't need it to drive the new amp, except for fader controls, and the above mentioned noise immunity/ground loop issues.) You might not be able to tell the difference with it in circuit or bypassed... Maybe others on the board can tell you which way is the typical way to go and which way has worked best for them.
GOOD LUCK! Southbound
Thread
Thread Starter
Forum
Replies
Last Post
detailersdomain
Wash & Wax
3
10-09-2015 10:13 PM