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2011 LTZ bass is gone after speakers replaced

6429 Views 31 Replies 8 Participants Last post by  Jawkn333
Note: Long post.

Well, I had been on the fence for a long time and finally decided to replace the 4 speakers before they decided to fail. They seem to be a common issue with enough and so I thought that prevention would be better than a cure. Well, this "physician" can't heal himself! :eek:

I chose Rockford Fosgate speakers for all 4 corners. I decided to go one step above basic and got their Punch series. For the front door 6½" speakers it was a choice of 6½" or 6¾", with the larger ones being 3-way and the smaller being 2-way, so I took the 3-ways for the same price. For the rear 6" x 9" I got the 2-way speakers.

I have the electrical drawings and carefully tested one of the 6x9 speakers on the left side by using jumper wires. Since they are 2-wire speakers with a built-in crossover and the stock Bose setup uses 4 wires, I was not able to get them to make enough sound. I even tried bridging them and they just didn't do it. I sent them back and got a pair of 2-way 6½" with separate tweeter and external crossover.

The speakers I now have are still all RF: P1675 in the front doors, P165-SE in the rear deck. (I returned the set of P1692 speakers.)

I just finished installing them today after getting the driver's door done Friday night. After getting it installed I was not all that thrilled with its sound output at all. I finished installing the left rear and it, too, was way too light on its bass. I figured I'd just finish all 4 and see if the Bose amp was somehow limiting what it outputs, kinda like the "weakest link" syndrome where the last original speaker was keeping them from making some noise. Nope, that didn't do it.

So here's my dilemma: I have absolutely no bass unless I turn it all the way up and drop the midtone and treble below center.

With all three settings in the center, I have to turn the volume up scary high just to hear a little bass, but then my ears are bleeding from all the SPL of the high notes. I've tried it on a USB file of several of Roy Orbison's songs as well as the SiriusXM tuner coming in on my Aux Input jack.

When I still had at least one stock speaker installed, I could run the fade/balance to that speaker and get deep, warm bass from it alone, but none of the others produced anything at all like it. And still don't!

The only good side in all of this is that I can now hear Roy's words much more clearly than the muddled sound from the stock speakers.

Can someone (or someones) help a fella out?
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Some pics.

Rear deck using 6x9 adapter that actually came with the front speakers. (Yes, they're clamped in since it was a lot easier than the prospect of drilling holes from underneath.)

Front speakers while I was doing the custom wiring.

68593


68596
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Are the speakers sealed to the interior panel well ? On my old '09 LS I cut off the OEM mounting rings off those one piece OEM speakers and made the replacement cheap coaxial Kenwood's I used to be able to mount to those rings so they sealed to the door panel and package shelf. It took some fabrication.
Front of speaker has to be sealed to inner panels so door or trunk acts like a air tight speaker box. I did the same with the rears. Loss of that ''air'' will kill the bass. That's why the cheap factory one have any bass at all.
My LS base radio had enough bass to vibrate the inside rearview when bass was cranked up with speakers sealed to the interior panels.
Think of how small bookshelf speakers are sealed, it's only for bass response. In vehicles the trunk and inner door are the ''speaker box''.
I'm assuming since you have wiring diagrams polarity is correct also.
Also the replacements will be more efficient so mids and highs will need to be backed off some.
They're not sealed to prevent air from being to pass around them. There is a path for them to "breathe".

When I can, I'll see what I can do to seal them, even if only for a test, and then see how they perform after that. It may be a week or two with everything that's going on in my life...

Have u ever thought about looking at these?


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Have u ever thought about looking at these?


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No, but that'll end directly. Thanks for the idea!
Well, I went looking and found it. Not only is it $500 but it fits everything 2013 and up so long as it's not a Malibu, so for me it's a lose-lose-lose:
  1. I paid less for the speakers than this device,
  2. Mine is older than 2013,
  3. Mine's a Malibu and it fits Cadillac, Chevy, and GMC trucks.
Well, I went looking and found it. Not only is it $500 but it fits everything 2013 and up so long as it's not a Malibu, so for me it's a lose-lose-lose:
  1. I paid less for the speakers than this device,
  2. Mine is older than 2013,
  3. Mine's a Malibu and it fits Cadillac, Chevy, and GMC trucks.
the bu is so difficult to customize


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Just a thought. Have you tried fading it all to the front or rear and adjusting the balance to just one side to see if the bass improves? If so, the speakers are out of phase with each other where one speaker cone is being driven out on one channel while the other channel is being pulled in. After testing that way, fade it the other direction and test again. It could be incorrect L to R only up front or only on the rear or it could be incorrect front to rear. Just experiment in an attempt to find a potential cause while sitting in the drivers seat. It may be an inexpensive fix if it turns out to be the issue. The polarity of the speaker inputs need to be changed. For example, swapping positive lead for negative lead. Ideally, all speaker cones need to be going the same direction while playing. Hope that you're able to get it corrected.
Note: Long post.

Well, I had been on the fence for a long time and finally decided to replace the 4 speakers before they decided to fail. They seem to be a common issue with enough and so I thought that prevention would be better than a cure. Well, this "physician" can't heal himself! :eek:

<snip>

So here's my dilemma: I have absolutely no bass unless I turn it all the way up and drop the midtone and treble below center.

With all three settings in the center, I have to turn the volume up scary high just to hear a little bass, but then my ears are bleeding from all the SPL of the high notes. I've tried it on a USB file of several of Roy Orbison's songs as well as the SiriusXM tuner coming in on my Aux Input jack.

When I still had at least one stock speaker installed, I could run the fade/balance to that speaker and get deep, warm bass from it alone, but none of the others produced anything at all like it. And still don't!

The only good side in all of this is that I can now hear Roy's words much more clearly than the muddled sound from the stock speakers.

Can someone (or someones) help a fella out?
DD, seeing that Bose designed these systems in the LTZ (I have one), I suspect that you're not getting the signal (for lack of a better description) that will supply your bass. I would think that unless you're swapping out the old speakers for OEMs, this is likely to happen. From my experience, Bose tends to make their systems a bit more complex & difficult to modify than the average factory-supplied systems, and I don't think their systems are designed to readily accept other manufacturer's components. I could be wrong!

Many years ago, I tried replacing the rear strut tower worn out Bose speakers on a friend's 300ZX many years with another speaker brand - it did not go well at all, and she was not happy! To me, the new speakers and their rating (watts, ohms, etc) appeared that they should have played well together, but I couldn't figure out what the problem was.

I haven't upgraded a car system in eons, but if I did, I'd probably contact Crutchfield. If they helped me, I'd buy the equipment, and they always had the answers.

Another idea would be to prowl around the net for some car stereo forums.... in those forums, see if you can find some message threads where someone was upgrading their Bu's system. Maybe you can see what minefields they encountered, or someone might be able to steer you towards a solution.

I know this doesn't help much, but it's food for thought.
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I'm probably grasping at straws here, but do you know the impedance of the OEM Bose speakers that came out? It's been years ago but I remember I was replacing some Bose speakers once and I recall the impedance that was marked on them was not what I would expect to see in a car audio application. Keep in mind i'm going off an old memory, but I want to say they were 8ohm speakers, like you would find on a home stereo system. If this is the case and the Bose amp is designed for higher impedance speakers this would mean the amp is having to push more power to get the same results out of the lower impedance 4ohm speakers and could explain the difference in your audio quality.

Of course this is just a guess on what your problem may be.
@Plague
Great memory! The stock ones are marked 8 ohms, the new ones are 4 ohms.

If I were to add a 4-ohm resistor in series with each speaker, that would bring it to the stock 8-ohm. The new speakers are capable of handling 55 watts RMS front and 60 watts RMS rear. What kind of wattage on the resistor would I need - a minimum of 60 watts, or would something smaller suffice?
DD - found this link regarding upgrading Bose speakers in GM vehicles.


Now, I don't think there's a specific answer in this forum for your particular application, and some of the comments (regarding a simple speaker swapout) are a bit puzzling to me, but, some more food for thought.

This second forum has some particularly interesting comments regarding impedence and bass reduction:


The truth is out there.... :rolleyes::alien:
@jes2
Thanks for those references! I just read them and it sounds like, as I feared, it'll need to have the Bose amp removed in favor of a new amp.

I guess the hunt is on...
Well, a little research on Crutchfield and they offer only one amp that replaces the stock Bose amp and still retains the factory chimes, etc.

Kenwood Excelon P-XR600-6DSP

Any thoughts?

Edit: I just chatted with Calvin at Crutchfield. I don't need that one with the Maestro AR because they don't offer a T-harness that will interface with my car.

He suggested a couple of amps.

The first was a 4-channel with 45 watts per channel. Kicker KEY180.4

The second was a 5-channel with 50 per channel plus 350 for the addition of a sub if I ever want to. (Need? Not likely...) Rockford Fosgate R2-750X5
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@jes2
Thanks for those references! I just read them and it sounds like, as I feared, it'll need to have the Bose amp removed in favor of a new amp.

I guess the hunt is on...
No prob! You've helped me on problems for my '10, and it was time to return the favor!

What I don't understand after reading comments about Bose from those websites is the surprising amount of dislike for the Bose system. Lot of bashers out there.

Long ago, I'd dropped some significant coin into custom sound systems in a Supra and in a Mustang.... Factory sound systems have come a long way since then, but with rare exceptions, most current premium factory sound systems in various vehicles suck. Not impressed, particularly for the added coin.

But, my LTZ's Bose system has been an exception. It was one of the reasons that I eventually bought the car. Not bad at all for a factory system.

I'll stay tuned - see if we can find some additional info to get you going!
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@Plague
Great memory! The stock ones are marked 8 ohms, then new ones are 4 ohms.

If I were to add a 4-ohm resistor in series with each speaker, that would bring it to the stock 8-ohm. The new speakers are capable of handling 55 watts RMS front and 60 watts RMS rear. What kind of wattage on the resistor would I need - a minimum of 60 watts, or would something smaller suffice?
I'm probably more surprised that I remembered that detail than anything. I used to build some car stereos on an amateur level over 20 years ago with some friends. Those same friends tried to open a car audio shop and wanted me to work there with them, but the small business loan fell through. Anyway I have no idea about using resistors, but the idea sounds possible, but I genuinely don;t want to say one way or the either because if it doesn't work I don't want to be held responsible for destroying your new speakers or the factory amp.

That said and after reading the other posts I think you may be better off with advice from Jes2 than from me. He seems to know a bit more about what's going on than I probably do.
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Just a thought. Have you tried fading it all to the front or rear and adjusting the balance to just one side to see if the bass improves? If so, the speakers are out of phase with each other where one speaker cone is being driven out on one channel while the other channel is being pulled in. After testing that way, fade it the other direction and test again. It could be incorrect L to R only up front or only on the rear or it could be incorrect front to rear. Just experiment in an attempt to find a potential cause while sitting in the drivers seat. It may be an inexpensive fix if it turns out to be the issue. The polarity of the speaker inputs need to be changed. For example, swapping positive lead for negative lead. Ideally, all speaker cones need to be going the same direction while playing. Hope that you're able to get it corrected.
Yes, I did try that, too. I checked the polarity and everything is polarized correctly. I wish it had been that simple, but it wasn't.

My chat with Calvin helped fill in some blanks, as did reading every post in those 2 threads that @jes2 posted. With @Plague getting my mind going in the right direction about the different impedances, and then some more reading about that Rockford Fosgate amp, I went ahead and ordered the RF amp, a 4-gauge kit, and 2 spare 100A fuses from Crutchfield. If it doesn't do what it says, I have 60 days to return it, so I feel comfortable enough about ordering it in that regard.

Whether it works or doesn't, I'll most definitely come back and share the results.
My '11 Tahoe with Bose has 4 ohm speakers in the rear doors. I changed them out due to a rattling one and have had no issues. It uses a ported sub inside the front console and a center dash speaker for voice frequency's in surround mode.
2
Well guys, here it is a day off and I'm ready to install my 5-channel amp to replace the Bose amp in the trunk. I've confirmed all of the wiring to the speakers, etc, based on a set of drawings that I've had for years.

The replacement amp has outputs for 4 channels plus a sub. I don't have a sub. However, the Bose system uses the rear 6x9 speakers as "subs" and the speakers mounted inside the cage as speakers. The Bose wiring has 6 separate wiring paths, not 4 or 5. I knew this before but didn't think about it until now. (Yay, last-minute preparation! :eek:)

Should I take the output from the sub channel and wire the new rear speakers (already installed a month ago) as the "subs" kinda like the Bose did, or come up with some other solution?

Edit: Added images.

68839


68840
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