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Discussion Starter #1
I've been reading through forums for about 2 hours. I am seeing a lot of issues with the driver door speaker and chimes. Please correct me if I am wrong, but I am assuming that the chimes only sound through this speaker. Could this possible be the reason that this speaker wears out faster than the others?

I have only had this car a little while, but since I got it, the driver side door speaker has worked intermittently, but when it worked, it worked well. I got in the car today, and the the first time the chimes sounded, they were so loud they scared me, after this no sound at all came from the radio. The lights came on, and all of the functions showed up on the display, but no sound. After a couple of starts, the radio started working again. Now the driver side door speaker is working, but it is rattling, like it is blown. I haven't been able to find a descent wiring diagram for this unit, so I am wondering if wherever the power is coming from for the chimes, could be malfunctioning enough to overload the speaker? Weird, I know. It is a stock non Bose system, although it has fuses for an amp (no amp between the back speakers) and onstar. Any info would be appreciated. Thanks.
 

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Well, I have done a bit more research, and have found others who have had the same issue, but there is never a resolution. I guess its exploratory surgery.
 

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Well, I have done a bit more research, and have found others who have had the same issue, but there is never a resolution. I guess its exploratory surgery.
I'm thinking you have a broken wire in the driver's door jamb. That door gets opened/closed the most, so its wires tend to fail first due to flexing and chafing.

You can pull back the rubber boot on each end and inspect for a broken wire. According to the schematic I have, look for the tan and gray wires. Check them for chafed spots where they've been rubbing on the metal.

The head units typically use bridged outputs. That means that, if one of the two wires to the speaker is shorting out due to chafing, you would get a much lower volume on that speaker (-6dB). Furthermore, if the head unit's output stage detects a short, it might go into a shutdown mode to protect the drivers.

IOW, the symptoms you describe seem to gibe with a chafed wire shorting to ground and/or a broken wire making intermittent contact (or both).

Doug

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Thank you for the reply Doug. I have a whole new set of speakers for this car I haven't put in yet. The first thing I will do is the driver door speaker and inspect the wiring as you suggested. The only thing that I am concerned about is that time when the chimes went nuts. I'm not talking about just turned up all the way loud, I'm talking about scary loud. But perhaps exposed wires could be responsible for that also.
 

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The only thing that I am concerned about is that time when the chimes went nuts. I'm not talking about just turned up all the way loud, I'm talking about scary loud. But perhaps exposed wires could be responsible for that also.
IIRC, there is a volume adjustment for the chimes. I'm thinking maybe they had been adjusted all the way up, then when the wiring, by chance, happened to work correctly (with no opens and no shorts), you got the full blast on the speaker.

Installing the speaker is the perfect time to inspect the wiring. With the door torn apart, you can release the wiring harness to give it some more slack for inspecting it in the jamb.

If you use pigtail adapters on the new speakers, be sure to bundle them up with some zip ties so they can't get caught in the window lift mechanism.

Doug

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Discussion Starter #7
There is a volume adjustment, but its only "normal' and "loud". I can't imagine the loudness I heard being of design, I'm still hoping for a simple wiring explanation. I am gong to be using some Metra adapers for the new speakers, so thanks for the zip tie tip.
 

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Finally got around to taking the door panels off. Couldn't find any bad wires, but the new speakers and the chimes are working great. Quite and increase in music quality. The stock speakers were not in very good shape.

 

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Something more. We bought a keyless entry because this car came without one. We got it on Amazon for $35. It claims to be "ACDelco 20935331 GM Original Equipment", although it is a five button, (we weren't sure what options we had, so we got one with all of them). We do not have the remote start, however, the rest of the buttons work. When you push the door lock on the keyless, it just locks the doors, but if you push it twice, it honks the horn. I double clicked it tonight, and when I got back in the chimes and radio were not producing any sound. After the next stop and restart, they were both back. Perhaps an issue with the remote or with the security system. I haven't researched this type much.
 

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The head units typically use bridged outputs.

Doug

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I've been trying to get a grasp on the term "bridged output". From what I understand it means putting 2 channels together, to give it double the output. But if I have a stock stereo with both balance and fade settings, doesn't that mean I am using 4 channels, and if they are bridged, wouldnt it have to be and 8 channel head unit? Confused.
 

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The stock speakers were not in very good shape.
That's the understatement of the year! Looks like the entire speaker surround is "gone" on that speaker! I'm amazed it produced any sound at all! :)

Sent from my HP SlateBook 10 x2 PC using Tapatalk
 

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I've been trying to get a grasp on the term "bridged output". From what I understand it means putting 2 channels together, to give it double the output. But if I have a stock stereo with both balance and fade settings, doesn't that mean I am using 4 channels, and if they are bridged, wouldnt it have to be and 8 channel head unit? Confused.
In the old days, when I was a teenager installing my first stereo in the mid 70's, standard amplifier outputs were comprised of one driver (one power transistor pair) whose output swung between ground and 12V (ie, battery voltage, nominally somewhere between 13.6 and 14.4V, but usually referred to as 12V). This 0-12V signal was coupled to the speaker thru a capacitor which blocked the DC component of the signal resulting in a signal that swung between –6 and +6V. (The cap also contributed to the roll-off at low frequencies.) The other side of the speaker was at ground. So the peak-to-peak signal was 12V. The average (ie, continuous or rms) power is Vpp^2/8R (for sinusoidal signals, the standard test signal used in measurements).

A bridged amp drives both sides of the speaker with signals 180° out of phase with each other. That's why car stereo installation instructions for the past 35 years have said to not ground any of the speaker wires coming out of the unit - they're all hot, whether labeled + or – :) (Minus ain't the same as ground, in a bridged system.)

Mathematically, this doubles the voltage seen by the speaker, even tho both wires are still only swinging between 0 and 12V. (It also eliminates the pesky blocking cap.)

By doubling the voltage, the power calculation becomes Vpp^2/2R - that's 4 times the power than before ! (Since power is proportional to V^2, doubling the voltage means (2V)^2=4V - ie, 4 times the power.)

So, in the old days, we usually had two drivers in the unit. These would swing 0-12V into 8 ohms for a whopping power of about 2.25W per channel (and only 2 channels).

Today, we have lower resistance speakers with 4 ohms common, and 2 ohms frequently available. A bridged unit will produce about 9W into 8 ohms, and 18 W into 4 ohms. (Over 20W if you consider most cars have nearer 14V rather than 12.) So that's 20W per channel, and 4 channels - a whole lot more bumping going on :)

So yeah, in a way, we have 8 channels. That is, in the old days, we had 2 channels each with one driver stage (ie, one transistor pair). Today, we have 4 bridged channels each with 2 driver stages - 8 transistor pairs instead of 2.

So that's how most head units are set up. Some newer ones use class D amplifiers (instead of the class AB amps described above). These use switching transistors instead of linear operation. These can get about 2 to 2.5x the output power of class AB, altho I still haven't figured out how they match themselves to the speakers which is necessary in switching applications.

The only other way to get more power is to have more voltage available. Most external amplifiers today have built in power supplies (ie, power converters) which take 12V in and produce –24V. That amounts to 36V total instead of 12V. In the same bridged amp application, with 3x the voltage, you end up with 9x the output power. So that 18W/channel class AB amp is now producing 160W/channel.

With that kind of power, folks like me are content to not crank it up all the way. (And most amps that claim much more power than that (into 4 ohms) are using a different power formula measured in bullshit watts.)
...
A few years ago, I was at Best Buy getting some parts for an install, and I overheard one of the installers say he could bridge two amps together to get more power. But he was talking out his @$$. The amps he was talking about already had bridged outputs. Trying to bridge two bridged amps would produce no more power - instead, more likely, it would probably result in something getting fried.
...
Hope this is useful.

Doug

.
 

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Discussion Starter #13
In the old days, when I was a teenager installing my first stereo in the mid 70's, standard amplifier outputs were comprised of one driver (one power transistor pair) whose output swung between ground and 12V (ie, battery voltage, nominally somewhere between 13.6 and 14.4V, but usually referred to as 12V). This 0-12V signal was coupled to the speaker thru a capacitor which blocked the DC component of the signal resulting in a signal that swung between –6 and +6V. (The cap also contributed to the roll-off at low frequencies.) The other side of the speaker was at ground. So the peak-to-peak signal was 12V. The average (ie, continuous or rms) power is Vpp^2/8R (for sinusoidal signals, the standard test signal used in measurements).

A bridged amp drives both sides of the speaker with signals 180° out of phase with each other. That's why car stereo installation instructions for the past 35 years have said to not ground any of the speaker wires coming out of the unit - they're all hot, whether labeled + or – :) (Minus ain't the same as ground, in a bridged system.)

Mathematically, this doubles the voltage seen by the speaker, even tho both wires are still only swinging between 0 and 12V. (It also eliminates the pesky blocking cap.)

By doubling the voltage, the power calculation becomes Vpp^2/2R - that's 4 times the power than before ! (Since power is proportional to V^2, doubling the voltage means (2V)^2=4V - ie, 4 times the power.)

So, in the old days, we usually had two drivers in the unit. These would swing 0-12V into 8 ohms for a whopping power of about 2.25W per channel (and only 2 channels).

Today, we have lower resistance speakers with 4 ohms common, and 2 ohms frequently available. A bridged unit will produce about 9W into 8 ohms, and 18 W into 4 ohms. (Over 20W if you consider most cars have nearer 14V rather than 12.) So that's 20W per channel, and 4 channels - a whole lot more bumping going on :)

So yeah, in a way, we have 8 channels. That is, in the old days, we had 2 channels each with one driver stage (ie, one transistor pair). Today, we have 4 bridged channels each with 2 driver stages - 8 transistor pairs instead of 2.

So that's how most head units are set up. Some newer ones use class D amplifiers (instead of the class AB amps described above). These use switching transistors instead of linear operation. These can get about 2 to 2.5x the output power of class AB, altho I still haven't figured out how they match themselves to the speakers which is necessary in switching applications.

The only other way to get more power is to have more voltage available. Most external amplifiers today have built in power supplies (ie, power converters) which take 12V in and produce –24V. That amounts to 36V total instead of 12V. In the same bridged amp application, with 3x the voltage, you end up with 9x the output power. So that 18W/channel class AB amp is now producing 160W/channel.

With that kind of power, folks like me are content to not crank it up all the way. (And most amps that claim much more power than that (into 4 ohms) are using a different power formula measured in bullshit watts.)
...
A few years ago, I was at Best Buy getting some parts for an install, and I overheard one of the installers say he could bridge two amps together to get more power. But he was talking out his @$$. The amps he was talking about already had bridged outputs. Trying to bridge two bridged amps would produce no more power - instead, more likely, it would probably result in something getting fried.
...
Hope this is useful.

Doug

.
Thats going to take my 55 year old mind some time to process it, but I will. I think possibly a new head unit is going to be the easiest way to go. Some of the ones I have seen look like they would put out enough power to run my speakers. Thanks again.
 

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Discussion Starter #14
That's the understatement of the year! Looks like the entire speaker surround is "gone" on that speaker! I'm amazed it produced any sound at all! :)

Sent from my HP SlateBook 10 x2 PC using Tapatalk

They were doing a little rattling, but still making music, I couldn't believe it either. Both door sides were like that.
 

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Well I don't want to say that there is something that can be DONE but sadly you can take 2 AMPS and put them together and in the end can in Theory get Double the output.... However as stated before if not done right or done with Matched AMPS could burn down your system lol.....

2 1000w amps not strapped (1 ohm each) = 2000w
2 1000w amps strapped (2 ohm) = 2000w

Takes less stress on the amp for same power output. Not every amp can be Strapped and some people don't want to do it as they don't think there is a Benefit. The power and stress put on the car battery and charging system sees the benefit. Also in this mode there is a Master Slave going on and you only have to tune one Amp as the Slave amp tune is now only same as the Master....

THere are a lot of people that don't like to do it. But if you can buy an amp that can be Strapped why not use it for what it was made to do...

James
 
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