WHAT'S GOOD? I HAVE A PROBLEM WITH THE ALTERNATOR NOISE COMING OUT OF MY SUBS. I AM RUNNING A PIONEER DEH-P5000UB HEAD UNIT, KICKER ZX700.5 AMP, AND TWO KICKER CVR12 DUAL 2 OHM SUBS. WHEN I CONNECTED EVERYTHING AT FIRST IT SOUNDED GREAT. BUT WHEN I WAS TRYING TO TUNE IT TO GET THE SOUND JUST RIGHT I STARTED TO GET THE WHINING NOISE. IT PROGRESSIVELY GOT WORSE OVER THE COURSE OF A FEW MINUTES. I AM JUST WONDERING WHAT COULD HAVE CAUSED IT TO START ALL OF A SUDDEN LIKE THAT?
Replies (14)
aone7706 on 03/25/2009 06:19:11
Oh, by the way I am running the stock alternator. I read on the Crutchfield site that the battery could also introduce noise into an audio system, and my battery has been in the car for the two years that I've had it (and who knows how long before that). I had the same head unit with a PZI 250.2 (Crunch), and 2 Audiobahn AW1200s with no problems like this except the time I tried to put an amp on my 6x9s.
swez on 03/25/2009 14:25:03
Most noise issues are caused by 3 common oversights:
1. Poor grounding of the entire system
2. RCA lines are too close to the power/ground lines that feed amps
3. Amp gain settings are incorrect
Proper grounding means all amps, EQ's and aftermarket HU have bare metal ground connections in the vehicle. The floorpan is a very good choice as it's one continous piece of sheet metal from the firewall to trunk.
RCA signal lines need at least 18 inches of separation from the main power cable. The power cable often emits noise and that will transfer to RCA lines if they are not separated. Back where the amp wiring comes together, don't bundle RCA's with power/ground cables. If they must cross, set them at 90 degree angles.
If the gain settings are too sensitive on the amp, it can pick up noise and amplify noise along with the audio signals. In this case, a Line Driver is used to kick up the RCA signals at the HU. This works very well in a package with EQ/LD added to the HU in the dash.
Swez
PS A good battery will last about 4-6 years. When the dying process shows up, the vehicle may start but just barely. Now, the ALT is working hard to charge it up and feed your amplifiers too. A simple load test at a good autoparts store will tell if your charging system is up to snuff or not. These tests can be done in the parking lot for free.
aone7706 on 03/25/2009 18:22:45
Thanks Swez. I got off work this morning and tried to see if I could find where it was coming from. I boiled it down to 1 of 2 things. Either the noise is getting introduced directly to the head unit or I just had my gains set too high. I pulled the RCA cables out and ran them down the middle of the seats and the noise was still there. Then I played with all of my settings and I got the noise down to a level where someone riding with me may not even notice it. Now I just have to figure how to stop my subs from picking up every sound in the music. Different elements in the music (finger snaps, really hard treble notes, and words but none of them produce sound) and the little bit of engine noise cause my subs to pulse at loud volumes and something tells me that over time that can cause some damage. THANKS AGAIN!!!!!!!!
aone7706 on 03/29/2009 00:34:04
I got everything lined out. the whole problem with noise was my rca jacks plugged in wrong. I had them going to the sub input. When I went back and actually read the manual I was supposed to plug them into the amp 1 input since I was only using that one pair. Then I put my 6x9s and tweeters on the amp. The tweeters didn't last 5 minutes. I guess 70 watts was too much for a pair of polk db1000s. I'm just mad because I got those off Ebay for $25. Now I can't find a new pair for under $70. All in the learning process right.
aone7706 on 03/29/2009 00:38:14
Man!!!!!!!! Those were some good clean sounding tweeters too.
swez on 03/29/2009 08:18:08
Solved one problem and created another? Bummer man...
Did this Polk tweeter kit come with passive inline filters? (If yes, were they installed?)
FYI: These tweets are rated at 60 watts RMS, above 4,000 Hz. If the passive crossover/filters were not used, they'd be toast in a few minutes at full range! (25 watts would fry them at full range)
http://www.crutchfield.com/S-klwqfefPnw8/p_107DB1000/Polk-db1000.html
Yes, Polk makes some great stuff. Have a pair of the original 7a's from 1978 and they still sound great from Classical to Rock, Jazz and most anything else. (Thou shall not play Rap on these babies) LOL They cannot handle those "juiced" bass attacks.
Swez
aone7706 on 03/29/2009 12:53:34
Okay. You caught me red-handed. I meant to put the crossovers back on but I forgot. When they were wired up on the HU the crossovers dulled the sound quite a bit. I guess because of the high pass filter on the HU. So I took the crossovers off and they sounded great. During all the excitement I just forgot to put them back.I guess I'll just have to shell out a few $$$$$ and get some more. I think they can handle 70 watts from a zx700.5.
swez on 03/29/2009 19:14:57
Just checking, but yes... the passive filters are there to limit the low frequency content to the tweeters. If we try to drive such a tiny speaker with full range music, they will die fast.
There are other options besides shelling out big cash on Polks too. You can even use other brands that handle more power and can be crossed over a tad lower too. Here's a list of well respected tweeters that can be used in your system. Many will be 6-8 ohm, but if the efficiency is high enough, (90+ dB SPL, 1w/1m) it won't be noticed:
http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=454&CFID=2810688&CFTOKEN=18317310
Goldwood is thier "value line" replacement speaker. Dayton is their "house brand" line. They will need filter caps of the proper value to keep them from frying out.
Finally, soft dome fabric tweeters sound the most natural. Metal dome tweets are brighter and give more "sizzle" too. To protect them from excess power, you can add an inline fuse too. If the power is too strong, the fuse will blow and save your tweeters.
Comments?
Swez
aone7706 on 03/29/2009 23:22:41
Thanks a lot. I'll check into it, but I think I want to go back with Polk. I'll just have to save a little cash and take my time. I have everything pretty much lined out. The two MTX 6x9s hooked up on the amp are doing great. They just don't have the crispness that the tweeters gave to the big picture. Although I was thinking of going with two more 3 way 6x9s, but I doubt it. Thanks a million
swez on 03/30/2009 15:49:52
Just a thought... 3-way Coaxials are generally not as clean, accurate and balanced as their 2-way kin. If you have them now in the rear, use em. But in the front stage, consider a quality pair of 2-ways.
Why? The crossover systems are "very inferior" to stand-alone Component systems and so are the Midrange elements. (Squawky mids)
A quality 2-way Coaxial speaker will deliver good Midbass, good extended Mids and good highs. They tend to use better speaker elements and the simplified crossovers blend better as well.
The more demanding your listening habits, the next step up are Component type systems. These are well balanced/matched speakers and high quality crossovers too. Amping them is the way to go for best performance.
High quality Coaxials speakers are also a good choice when they employ outboard crossovers. The crossovers are superior to the simple cap & coil filter networks used in cheaper models. Either of these options have the benefit of quality crossovers.
Think it over before you spend your hard earned $$$ OK?
Swez
aone7706 on 03/31/2009 03:17:36
Sound advice if you ask me. The components do seem as if they would sound better. Really they are separate speakers with external crossovers, huh. I think I'll save those for my next project. My wife likes the sound in my car. But she pretends that her factory radio is good enough with the aftermarket speakers she got installed. But her radio is toast as far as I'm concerned. No fader, it just makes a crackling noise when you try to adjust it. The volume knob doesn't work. Thanks for the great idea. A decent head unit a set of components, and an amp is all she needs. I'll let you know how it goes (when I get the money to get started).
swez on 03/31/2009 04:30:52
Exactly!
Take your time,do some research and wait for the best deals as prices are falling as demand is low and inventories are being liquidated to reduce overhead. (A great time to buy for much of 2009)
One product I have been very impressed with for some time, Infinity Reference and Kappa Series Comps. They come in 2-way Comps or Coaxials and there's even a 2-ohm version for amped systems.
IMHO, the Ref Series is the best value of the two. After specifying them to others and installing a few myself, they are hard to beat for the money.
Swez
aone7706 on 04/5/2009 02:53:22
I caught a used pair of Polk db1000s and what a difference they make. I ended up paying $25 for these too. I put the crossovers on this time. The system sounds great now.
I really must thank you for all your help once again. I think I'm through with my car for a while. Once I get a few dollars put away I'll get started on my wife's car. Let you know how it goes.
Thanks again
A-1
swez on 04/5/2009 10:55:06
Great score on a new pair of Polk tweets... enjoy the tunes and come back often.
You are most welcome!
Swez
Replies (14)
aone7706 on 03/25/2009 06:19:11
Oh, by the way I am running the stock alternator. I read on the Crutchfield site that the battery could also introduce noise into an audio system, and my battery has been in the car for the two years that I've had it (and who knows how long before that). I had the same head unit with a PZI 250.2 (Crunch), and 2 Audiobahn AW1200s with no problems like this except the time I tried to put an amp on my 6x9s.
swez on 03/25/2009 14:25:03
Most noise issues are caused by 3 common oversights:
1. Poor grounding of the entire system
2. RCA lines are too close to the power/ground lines that feed amps
3. Amp gain settings are incorrect
Proper grounding means all amps, EQ's and aftermarket HU have bare metal ground connections in the vehicle. The floorpan is a very good choice as it's one continous piece of sheet metal from the firewall to trunk.
RCA signal lines need at least 18 inches of separation from the main power cable. The power cable often emits noise and that will transfer to RCA lines if they are not separated. Back where the amp wiring comes together, don't bundle RCA's with power/ground cables. If they must cross, set them at 90 degree angles.
If the gain settings are too sensitive on the amp, it can pick up noise and amplify noise along with the audio signals. In this case, a Line Driver is used to kick up the RCA signals at the HU. This works very well in a package with EQ/LD added to the HU in the dash.
Swez
PS A good battery will last about 4-6 years. When the dying process shows up, the vehicle may start but just barely. Now, the ALT is working hard to charge it up and feed your amplifiers too. A simple load test at a good autoparts store will tell if your charging system is up to snuff or not. These tests can be done in the parking lot for free.
aone7706 on 03/25/2009 18:22:45
Thanks Swez. I got off work this morning and tried to see if I could find where it was coming from. I boiled it down to 1 of 2 things. Either the noise is getting introduced directly to the head unit or I just had my gains set too high. I pulled the RCA cables out and ran them down the middle of the seats and the noise was still there. Then I played with all of my settings and I got the noise down to a level where someone riding with me may not even notice it. Now I just have to figure how to stop my subs from picking up every sound in the music. Different elements in the music (finger snaps, really hard treble notes, and words but none of them produce sound) and the little bit of engine noise cause my subs to pulse at loud volumes and something tells me that over time that can cause some damage. THANKS AGAIN!!!!!!!!
aone7706 on 03/29/2009 00:34:04
I got everything lined out. the whole problem with noise was my rca jacks plugged in wrong. I had them going to the sub input. When I went back and actually read the manual I was supposed to plug them into the amp 1 input since I was only using that one pair. Then I put my 6x9s and tweeters on the amp. The tweeters didn't last 5 minutes. I guess 70 watts was too much for a pair of polk db1000s. I'm just mad because I got those off Ebay for $25. Now I can't find a new pair for under $70. All in the learning process right.
aone7706 on 03/29/2009 00:38:14
Man!!!!!!!! Those were some good clean sounding tweeters too.
swez on 03/29/2009 08:18:08
Solved one problem and created another? Bummer man...
Did this Polk tweeter kit come with passive inline filters? (If yes, were they installed?)
FYI: These tweets are rated at 60 watts RMS, above 4,000 Hz. If the passive crossover/filters were not used, they'd be toast in a few minutes at full range! (25 watts would fry them at full range)
http://www.crutchfield.com/S-klwqfefPnw8/p_107DB1000/Polk-db1000.html
Yes, Polk makes some great stuff. Have a pair of the original 7a's from 1978 and they still sound great from Classical to Rock, Jazz and most anything else. (Thou shall not play Rap on these babies) LOL They cannot handle those "juiced" bass attacks.
Swez
aone7706 on 03/29/2009 12:53:34
Okay. You caught me red-handed. I meant to put the crossovers back on but I forgot. When they were wired up on the HU the crossovers dulled the sound quite a bit. I guess because of the high pass filter on the HU. So I took the crossovers off and they sounded great. During all the excitement I just forgot to put them back.I guess I'll just have to shell out a few $$$$$ and get some more. I think they can handle 70 watts from a zx700.5.
swez on 03/29/2009 19:14:57
Just checking, but yes... the passive filters are there to limit the low frequency content to the tweeters. If we try to drive such a tiny speaker with full range music, they will die fast.
There are other options besides shelling out big cash on Polks too. You can even use other brands that handle more power and can be crossed over a tad lower too. Here's a list of well respected tweeters that can be used in your system. Many will be 6-8 ohm, but if the efficiency is high enough, (90+ dB SPL, 1w/1m) it won't be noticed:
http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=454&CFID=2810688&CFTOKEN=18317310
Goldwood is thier "value line" replacement speaker. Dayton is their "house brand" line. They will need filter caps of the proper value to keep them from frying out.
Finally, soft dome fabric tweeters sound the most natural. Metal dome tweets are brighter and give more "sizzle" too. To protect them from excess power, you can add an inline fuse too. If the power is too strong, the fuse will blow and save your tweeters.
Comments?
Swez
aone7706 on 03/29/2009 23:22:41
Thanks a lot. I'll check into it, but I think I want to go back with Polk. I'll just have to save a little cash and take my time. I have everything pretty much lined out. The two MTX 6x9s hooked up on the amp are doing great. They just don't have the crispness that the tweeters gave to the big picture. Although I was thinking of going with two more 3 way 6x9s, but I doubt it. Thanks a million
swez on 03/30/2009 15:49:52
Just a thought... 3-way Coaxials are generally not as clean, accurate and balanced as their 2-way kin. If you have them now in the rear, use em. But in the front stage, consider a quality pair of 2-ways.
Why? The crossover systems are "very inferior" to stand-alone Component systems and so are the Midrange elements. (Squawky mids)
A quality 2-way Coaxial speaker will deliver good Midbass, good extended Mids and good highs. They tend to use better speaker elements and the simplified crossovers blend better as well.
The more demanding your listening habits, the next step up are Component type systems. These are well balanced/matched speakers and high quality crossovers too. Amping them is the way to go for best performance.
High quality Coaxials speakers are also a good choice when they employ outboard crossovers. The crossovers are superior to the simple cap & coil filter networks used in cheaper models. Either of these options have the benefit of quality crossovers.
Think it over before you spend your hard earned $$$ OK?
Swez
aone7706 on 03/31/2009 03:17:36
Sound advice if you ask me. The components do seem as if they would sound better. Really they are separate speakers with external crossovers, huh. I think I'll save those for my next project. My wife likes the sound in my car. But she pretends that her factory radio is good enough with the aftermarket speakers she got installed. But her radio is toast as far as I'm concerned. No fader, it just makes a crackling noise when you try to adjust it. The volume knob doesn't work. Thanks for the great idea. A decent head unit a set of components, and an amp is all she needs. I'll let you know how it goes (when I get the money to get started).
swez on 03/31/2009 04:30:52
Exactly!
Take your time,do some research and wait for the best deals as prices are falling as demand is low and inventories are being liquidated to reduce overhead. (A great time to buy for much of 2009)
One product I have been very impressed with for some time, Infinity Reference and Kappa Series Comps. They come in 2-way Comps or Coaxials and there's even a 2-ohm version for amped systems.
IMHO, the Ref Series is the best value of the two. After specifying them to others and installing a few myself, they are hard to beat for the money.
Swez
aone7706 on 04/5/2009 02:53:22
I caught a used pair of Polk db1000s and what a difference they make. I ended up paying $25 for these too. I put the crossovers on this time. The system sounds great now.
I really must thank you for all your help once again. I think I'm through with my car for a while. Once I get a few dollars put away I'll get started on my wife's car. Let you know how it goes.
Thanks again
A-1
swez on 04/5/2009 10:55:06
Great score on a new pair of Polk tweets... enjoy the tunes and come back often.
You are most welcome!
Swez
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