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View Full Version : Silverado Speakers? - Guitar Focus



freighttrain
03-10-2004, 09:55 AM
I'm looking to upgrade the front factory 6.5" door mount speakers in my 2002 Silverado (Crew Cab). I'm not a bass freak, but I love rock/blues guitar (SRV, Jonny Lang, KW Shepard, etc.) and the factory speakers just ain't gettin it. I don't have an amp (might add in the future) so I'll be running these off my GM/Delco head unit.
I currently seem to have (unplanned) distortion on the higher (guitar) frequencies at volume. I have some hearing loss at the high frequency ranges (from too many 'center stage' rock concerts - my wife and kids laugh at me cause I can't hear my cellphone beeping from across the room).
I don't know squat about tweeter design or composition, or woofer composition or surround. These seem to be the differentiating factors when I look at online comparisons.
Initial research in my price range (around $200) includes Alpine, Infinity, Pioneer, Polk, Kenwood, Sony, JBL, but that's just what was on a few websites I visited (that said they'd fit my truck).
I am newbie to the site, so if there are other posts that answer these basic questions, just point me to them. Otherwise, any sage advice would be much appreciated.
FT

helotaxi
03-10-2004, 08:19 PM
Hate to say it but the amp section in your Delco head unit is the source of your distortion. As you turn it up the tiny amp section reaches its limits and begins to clip giving the distortion that you want to get rid of. You have two simple options on how to get rid of the distortion, and neither invlove replacing your speakers. Option 1 is to replace the head unit with and aftermarket one that has a decent amp section in it. That will get you more volume before clipping and distortion. The other and IMHO better option is to get a small amp to take the signal from your stock HU and amplify it to your stock speakers. Benefits are maintaining stock appearance (theft deterrance) and better amplification. Even HU's with good amp sections are not able to keep up with a dedicated amp, even an inexpensive one. You won't need much power, maybe 25 watts per channel RMS. If you decide to upgrade your speakers later, you already have an amp to take proper advantage of the added sound quality of the new speakers.

B_Master_Flash
03-10-2004, 10:12 PM
Hate to say it but the amp section in your Delco head unit is the source of your distortion. As you turn it up the tiny amp section reaches its limits and begins to clip giving the distortion that you want to get rid of. You have two simple options on how to get rid of the distortion, and neither invlove replacing your speakers. Option 1 is to replace the head unit with and aftermarket one that has a decent amp section in it. That will get you more volume before clipping and distortion. The other and IMHO better option is to get a small amp to take the signal from your stock HU and amplify it to your stock speakers. Benefits are maintaining stock appearance (theft deterrance) and better amplification. Even HU's with good amp sections are not able to keep up with a dedicated amp, even an inexpensive one. You won't need much power, maybe 25 watts per channel RMS. If you decide to upgrade your speakers later, you already have an amp to take proper advantage of the added sound quality of the new speakers.

agreed. bad power = bad sound. of course it's slightly more complicated than that, but you get the idea. I would have to say I would push more towards an aftermarket HU though, wrining amps to factory HUs, especially speaker amps, usualy involves a lot of interference, b/c you have to either use high level input to the speakers, or a high-->low adapter (both are bad). An aftermarket HU will have an adequate amp for your speakers, and it will have preamp outputs which give a much cleaner signal if you decide to go with an external amp. You may have to replace your speakers also, b/c of the added power. Prolly not immediately, but if your stock speakers are like most, the are made to handle only what the stock HU puts out, usualy not more than 10watts/channel. An aftermarket HU will most likely be about 25 watts/channel, and an external amp will be at least 40watts/channel. That ammount of power will eventually destory the coil or the suspension. Just follow my advice, and you will be way over budget in no time :thumbsup

helotaxi
03-10-2004, 10:44 PM
agreed. bad power = bad sound. of course it's slightly more complicated than that, but you get the idea. I would have to say I would push more towards an aftermarket HU though, wrining amps to factory HUs, especially speaker amps, usualy involves a lot of interference, b/c you have to either use high level input to the speakers, or a high-->low adapter (both are bad).
With a good high-low adapter you won't be able to tell the difference between the factory HU and an aftermarket one. Many a USAC and IASCA World Champ has used the factory HU in their SQ system.

An aftermarket HU will have an adequate amp for your speakers, and it will have preamp outputs which give a much cleaner signal if you decide to go with an external amp. You may have to replace your speakers also, b/c of the added power. Prolly not immediately, but if your stock speakers are like most, the are made to handle only what the stock HU puts out, usualy not more than 10watts/channel. An aftermarket HU will most likely be about 25 watts/channel
They are distorting hugely at that power level just like his factory one is. You can always turn down the gain of an amp to limit it's power to keep from blowing speakers and use the high pass filter that most all amps have now to limit the bass going to the factory speakers and increase their power handling as well.

B_Master_Flash
03-10-2004, 10:48 PM
call me crazy, but if turing down the gain and cutting the bass isnt a problem, why get an aftermarket anything? I thought he wanted music. And when you say "they're distorting hugely at that power level just like the factory one is" are you comparing the 25 watt rms of an aftermarket HU to the (probably around) 10 watt rms of the factory unit? Cuz thats what it sounded like. And if that is the logic, you're saying getting a more powerfull amp is pointless if it distorts at its max output? Have you ever installed an aftermarket HU? Or a high-->low adapter? Sounds like your info is coming from an encyclopedia.

helotaxi
03-11-2004, 12:56 AM
call me crazy, but if turing down the gain and cutting the bass isnt a problem, why get an aftermarket anything?
OK, you're crazy. The factory speakers are not going to be able to handle much power if there is low bass involved. Adding more power without addressing the limitations of the factory speakers will make them distort, and then he is back to square one. I can just about guarantee that the factory speakers with a small amp with the gain turned down to limit its power to keep it from cooking the speakers will sound better than aftermarket speakers being powered by a factory HU or the factory speakers running off an aftermarket HU. Most HUs have a terrible amp section, that is the fact of the matter. I have seen rated 27 RMS from a HU (the one I currently have in my car in fact) and that is with 10% distortion. Unacceptable IMO.

And when you say "they're distorting hugely at that power level just like the factory one is" are you comparing the 25 watt rms of an aftermarket HU to the (probably around) 10 watt rms of the factory unit? Cuz thats what it sounded like. And if that is the logic, you're saying getting a more powerfull amp is pointless if it distorts at its max output?
Look at the distortion at the rated power. Most real amps have less than 0.5% THD at their rated output. Most HU's have 10%. That is a HUGE difference. Sure the after market HU will get a little louder than stock but it will still distort like crazy doing it.

Have you ever installed an aftermarket HU? Or a high-->low adapter? Sounds like your info is coming from an encyclopedia.
I have installed more HU's than I can remember. A line-level convertor or two as well. I have also read a bunch and spent a lot of time hanging around shops and install bays talking to guys who do this stuff for a living and picking their brain. I have a lot of knowlege from numerous sources including real world experience and I will not steer a guy in the wrong direction.

B_Master_Flash
03-11-2004, 01:49 AM
Most HUs have a terrible amp section, that is the fact of the matter.

Yes I agreed w/ you there. I even emphasised it more, just adding an amp to a factory HU means you will have to amplify the signal AFTER its been through the HU's amplifier. Making garbage 10x louder is still gargabe. Also you will be amplifying any interference that the unshielded speaker wire is subjected too. Its a trade-off, the higher you set the gain on the external amp, the more you will amplify interference. The lower you set the amp, the more you have to turn the volume up on the HU, making a distorted signal from the HU's amp. Whether or not comptetitors use high-->low converters, interference is a SERIOUS problem w/ them, especially w/ speaker amps. Solution = Aftermarket HU.


Sure the after market HU will get a little louder than stock but it will still distort like crazy doing it.

Every aftermarket HU I've installed to replace an OEM HU got much louder and didn't distort nearly as easily.


I have installed more HU's than I can remember. A line-level convertor or two as well. I have also read a bunch and spent a lot of time hanging around shops and install bays talking to guys who do this stuff for a living and picking their brain. I have a lot of knowlege from numerous sources including real world experience and I will not steer a guy in the wrong direction.

Never said your intentions weren't benevolent, I just disagree. I think the HU should be replaced before any speaker amps are installed.

freighttrain
03-11-2004, 11:57 AM
OK guys, appreciate the input AND the difference of opinion. It's helping me consider my options, as well as what I might be in for. You both agree on the starting point of the problem....


........ the amp section in your Delco head unit is the source of your distortion. As you turn it up the tiny amp section reaches its limits and begins to clip giving the distortion that you want to get rid of..

It seems like both of you agree on the two options.........


You have two simple options on how to get rid of the distortion, and neither invlove replacing your speakers. Option 1 is to replace the head unit with and aftermarket one that has a decent amp section in it. That will get you more volume before clipping and distortion. The other and IMHO better option is to get a small amp to take the signal from your stock HU and amplify it to your stock speakers. Benefits are maintaining stock appearance (theft deterrance) and better amplification.

The difference of opinion seems to be on which 'path' I should take.
Right now, I'm leaning toward the external amp solution, largely because......
1) I've already got a 4-channel Kenwood amp that's sitting around (bought it for my son's car, but he was a bad boy and we sold the car... but not before I pulled the amp out).
2) The 'stock appearance' benefit HELOTAXI mentions is important to me. It also won't mess with my factory features (delayed turn-off, etc.), and it's one less item I have to buy to get 'somewhere' better than where I am now.
3) I'm already committed mentally to the speaker replacement (probably CDT, either CL-61a's or HD-62EF's, after subsequent research).

What still concerns me is the discussion on interference from the high-low adapter and other wiring. Given that everything is probably a 'matter of degrees' and somewhat subjective........ if I take the external amp / new speaker approach, will the high-low adaptor and other interference be a recognizable problem or not? If so, what's the best way to get around it, or at least reduce the problem?
Also, what problems am I likely to run into trying to wire this into my Delco HU?

A million thanks to both of you!!!!

B_Master_Flash
03-11-2004, 04:27 PM
Ok sounds like you will be going w/ the external amp stock HU path, so I would just have to say that you need to get a decent set of RCAs (just make sure when you get the amp kit, the RCAs are shielded, ie dont look like speaker wire), and intall the high-->low adapter as close to the HU as possible so that you leave as little speaker wire open for interference as possible (RCAs are shielded, speaker wire is not). Once it is installed, turn the gain on the amp all the way up w/ the truck running. turn the volume on the HU all the way down (but still have it on). Play w/ the throttle and see what kind of interference you can hear over the speakers, you'll prolly hear alternator whine. Turn the gain on the amp down until you can't hear the interference anymore, but still keep it as high as possible. Then turn the volume up on the HU and see how it sounds. Thats the best way I have found to tweak an amp that is wired through a high-->low adapter. Also make sure you keep the RCAs 18" away from the power/ground wires when running them, it's best to run them on opposite sides of the car. Remember that if you're hearing interference over your speakers, the most simple solution is to turn the gain on the amp down and the volume on the HU up.

freighttrain
03-12-2004, 12:39 AM
Yeah, it's a stepwise, not exclusionary, approach based on the gear I've already got and the info you guys posted. Like I said, I was already mentally committed to the speakers, so I feel like I can take this step and see how it sounds. If I'm still not happy I'll change out the HU and end up with what should be a pretty sweet setup. If the first step works out, so much the better.
I'll let you guys know how t turns out ('prolly' be a couple of weeks before I get it done).

Thanks again for your help.

Earle

B_Master_Flash
03-12-2004, 01:32 PM
Yeah, it's a stepwise, not exclusionary, approach based on the gear I've already got and the info you guys posted. Like I said, I was already mentally committed to the speakers, so I feel like I can take this step and see how it sounds. If I'm still not happy I'll change out the HU and end up with what should be a pretty sweet setup. If the first step works out, so much the better.
I'll let you guys know how t turns out ('prolly' be a couple of weeks before I get it done).

Thanks again for your help.

Earle

A new deck will only cure any interference problems. If you have speaker distortion then new speakers would be the way to go. Remember to use the HPF on the amp (high pass filter) to limit the ammount of deep bass to the speakers. I would recommend setting it to about 100hz, maybe a little lower. Turning the bass down on your HU will be simmilar but not as effective.

helotaxi
03-14-2004, 10:32 PM
Ok sounds like you will be going w/ the external amp stock HU path, so I would just have to say that you need to get a decent set of RCAs (just make sure when you get the amp kit, the RCAs are shielded, ie dont look like speaker wire), and intall the high-->low adapter as close to the HU as possible so that you leave as little speaker wire open for interference as possible (RCAs are shielded, speaker wire is not).
Shielded or not, speaker level signals are not succeptible to interference. I'm not saying that they are impervious to noise but they are less likely to pick it up than a low-level signal. Tap into the speaker wires wherever it's convenient.
Once it is installed, turn the gain on the amp all the way up w/ the truck running. turn the volume on the HU all the way down (but still have it on). Play w/ the throttle and see what kind of interference you can hear over the speakers, you'll prolly hear alternator whine. Turn the gain on the amp down until you can't hear the interference anymore, but still keep it as high as possible.
Get a good high-low converter and it will have adjustable input and output levels. Set the HU volume to about 3/4's. Measure the output with a multimeter and set the input on the converter accordingly. Set the output to the max that the input of the amp is rated for. Now set the gain on the amp to just slightly more than the absolute minimum. A low gain setting on the amp is going to be less likely to give audible noise.

Also make sure you keep the RCAs 18" away from the power/ground wires when running them, it's best to run them on opposite sides of the car.
Not required. Almost all noise induced in an audio system is caused by ground loop issues, not noise induced in the RCAs.
Remember that if you're hearing interference over your speakers, the most simple solution is to turn the gain on the amp down and the volume on the HU up.
That is usually the best solution for hiss and background noise, yes but if alternator whine is the problem then moving component grounds generally is the only real way to get results.

The outputs on the stock headunit will clip at a lower power than the outputs on a aftermarket unit but at about the same spot in their respective volume ranges. It will not be any more of a problem than it is with any other HU and amp combo. If you are not into really cranking the volume then you won't notice any difference. As long as you know where the HU starts to distort audibly and set the converter and amp to make their max power at or below that level, it will not be an issue at all. You won't need as much volume range either because with more power on tap (much more actually) you can get much louder with less of the available volume. What was full volume and distorted before will be a quarter volume and clear with the upgrade.

B_Master_Flash
03-15-2004, 12:16 AM
Not required. Almost all noise induced in an audio system is caused by ground loop issues, not noise induced in the RCAs.


Ok, I'm declaring shananagins. Keep the RCA's away from the power wire, any installer worth his weight in salt can tell you that. You can literally hold the RCA wire while listening to your system, and put it next to the power wire and hear the inteference.

helotaxi
03-15-2004, 07:43 PM
OK, call whatever you want. I have zip-tied the RCAs to the power wire and had no problems on more than one occasion. There are many myths that have been around car audio since its infancy and they have been propagated for years. Just because that's the way it's always been done. If you are picking up noise from your DC power cable on an AC signal cable, you have something else going on ie a noisy power feed.

tobz
03-15-2004, 08:54 PM
If your amp has speaker level inputs, you might want to look into them. They have worked wonderfully in all of the installs that I have done that use them.