Dynamolyd i høytalerene!

[danjohan]

Morn

 

Jeg driver å hjelper en kompis med å montere anlegg i bilen hans. Han har en Volvo 740. 92. mod trur jeg. Probemet er at det er dynamostøy i høytalerene når vi starter bilen. Sjukt iritabelt! Også fucker det bilen etter en stund. Vi veit 99% at vi har kobla riktig. Signal kabelene på den ene siden og strøm på den andre. Alle kablene ligger skilt godt fra hverandre bak også. Vi har prøvd i timesvis å finne problemet, men uten hell.

 

Vi har til slutt kommet fram til at det kanskje er selve dynamoen i volvo 740 som er dårlig jordet orginalt. Men vi har ikke prøvd å jorde den bedre enda. Er ikke helt sikkre på om det er det heller!

 

 

Hva kan det være? Noen som har vært borti det før? Jeg gjentar, alt er kobla riktig. Jordinga til forsterkern er kjempe bra. Rett i karosseriet, pusset og skrudd.

 

 

Eller er det bare Volvo 740 som er sånn??

 

 

Den forrige 740'en han hadde brant opp pga. dynamostøy >_<

 

 

Vil helst finne ut av det denne gangen

 

 

Takk

[kpolberg]

Har du gjort om på kablingen til spilleren foran da? Problemet det er snakk om her er vel potensial forskjellene til jord.

Diverse linker som kan hjelpe deg.

 

carputer

 

enda en tråd fra carputer.

 

groundloops

 

Har egentlig en link til, fant den bare ikke igjen akkurat nå. Men tror dette bør gi deg en pekepinn om hva som trengs å gjøre. Men uansett, det er aldri feil å bytte ut jord kabelen til karosseriet med noe tykkere. Det kan i hvertfall ikke gjøre det værre

[Morel]

Har dere jordet spilleren på skikkelig vis?

Dette glemmer mange og da oppstår det støy.

 

Mvh

Pål

[danjohan]

Har dere jordet spilleren på skikkelig vis?

Dette glemmer mange og da oppstår det støy.

 

Mvh

Pål

5623056[/snapback]

 

 

Ja, den er jordet med en feit jordingskabel, lik som forsterkern

 

 

Men var å snakka med en som jobber på Hifi Klubben, han sa vi måtte kjøpe et slaks strøm filter ellerno som vi monterte på "+" .. Skal kjøpe det og se om det hjelper..

[epifant]

Et strømfilter er ingenting annet enn et plaster, og vil aldri bli det. Lar man være å kutte seg, vil man heller ikke ha behov for plaster. Dersom ting er gjort riktig skal det ikke være behov for et strømfilter, så enkelt er det

 

PS: hvordan får man biler til å brenne av dynamostøy?

Endret 18. februar 2006 av epifant

[nahojdat]

Strømfilter :!:

Samme jobben blir gjort med å sette en tynn jordingskabel ytterst på phonoutgangene til spilleren.

[Morel]

Det er bare amatører som benytter seg av "strømfilter" helst kalt kondensator.

Hvis jordingene er dårlige eller feil plassert så oppstår det dynamostøy.

Husk at det spiller en stor rolle HVOR på karosseriet du fester jordingen fra spilleren!

Jeg har hatt mange biler og deriblandt Volvo, men har ALDRI vårt plaget med dynamostøy eller annen støy!

Flaks, kanskje?

Jeg sier "logisk tankegang" med et snev av kunnskap.

 

God helg, folkens!

 

Mvh

Pål

[knut-eirik]

Morn

 

Jeg driver å hjelper en kompis med å montere anlegg i bilen hans. Han har en Volvo 740. 92. mod trur jeg. Probemet er at det er dynamostøy i høytalerene når vi starter bilen. Sjukt iritabelt! Også fucker det bilen etter en stund. Vi veit 99% at vi har kobla riktig. Signal kabelene på den ene siden og strøm på den andre. Alle kablene ligger skilt godt fra hverandre bak også. Vi har prøvd i timesvis å finne problemet, men uten hell.

 

Vi har til slutt kommet fram til at det kanskje er selve dynamoen i volvo 740 som er dårlig jordet orginalt. Men vi har ikke prøvd å jorde den bedre enda. Er ikke helt sikkre på om det er det heller!

 

 

Hva kan det være? Noen som har vært borti det før? Jeg gjentar, alt er kobla riktig. Jordinga til forsterkern er kjempe bra. Rett i karosseriet, pusset og skrudd.

 

 

Eller er det bare Volvo 740 som er sånn??

 

 

Den forrige 740'en han hadde brant opp pga. dynamostøy >_<

 

 

Vil helst finne ut av det denne gangen

 

 

Takk

5618487[/snapback]

Det er riktig å legge strømm og signal på hver sin side av bilen, men har dere brukt den lille kabelen som er på signal kablene (som regel i midten) til rtemote for forsterkeren? Det skal ikke gjøres den biten bør jordes og så bør forsterker og spiller jordes på samme plass.

For å bli kvitt problemet så ta 2 ledninger (jord fra spilleren og remote) og legg sammen med strømkabelen, vipps så er problemet borte.

[Zeph]

Husk at det spiller en stor rolle HVOR på karosseriet du fester jordingen fra spilleren!

5624527[/snapback]

Har lokasjon betydning eller er du good-to-go så lenge du finn eit punkt på karosseriet og fjerner litt maling?

 

Er det dårligare jordforhold i ramma rundt spelaren enn andre stader?

[nahojdat]

Rundt rammen til spilleren er nok langt fra optimalt, selv bruker jeg alltid et punkt framme i motor-rommet, hvor du plasserer jordingen har en god del å si..

[kpolberg]

Linkene som jeg nevnte ovenfor tar opp alt dette, og hvorfor jordingspunktet er så viktig. Men, igjen det virker ikke som det er så mange som er hypp på å trykke på en link så jeg paster det bare rett inn.

 

This thread is being started as one to view if your are experiencing noise in your sound system. It is a fact that the automobile electrical system is one of the nastiest environments known to electronic equipment. There are three kinds of noise you can experience, thermal noise, induced noise, and noise caused by a ground loop. Thermal noise exists because mankind lives at about 300 degrees above absolute 0. It cannot be eliminated due to it's nature, but it can be minimized by carefully setting up your system to eliminate excessive heat. Good ventilation for your amplifiers and operating them within the limits recommended by the mfg. will minimize this kind of noise. It is the other two kinds that this thread will address.

 

Ground loops are insidious. Typically ground loops are created by a pieces of equipment having muliple connections being introduced into the system and being grounded at points of unequal resistance . Alternator whine is induced into the system because of this. Here are some suggestions for eliminating ground loops.

 

1) The "Big 3" Upgrade ( check out the sticky at the top of this section for detailed information ). This is essential because it allows you to insure that your system is getting maximum output from your alternator, but more importantly, it incorporates the chassis of your vehicle as the primary grounding terminal. The key here, as related to ground loops, is the battery's negative ground to the chassis, and the chassis ground to the engine block (the grounding point of your alternator). This should be completed using a gauge wire of equal or larger size than your primary power wire in order to eliminate a variation in resistance. Once you have completed this task you have now turned your vehicles chassis into a common grounding point for your systems components.

 

2) The Head Unit ground. The wiring harness attached to your factory HU should not be used to ground your new head unit. That harness is usually grounded to the dash along with all of the other electrical devices (turn signals, wipers, etc.) You need to run a separate ground wire (at least 16 gauge) from the black ground wire from the back of your head unit to a point on the vehicle's chassis. This ground point needs to be scraped and sanded to the bare metal. It is best advised to carefully drill a bolt hole through the chassis, scrape and sand both sides, and connect the ground wire using a ring terminal, bolt and nut, and lock washers on both sides to insure a good tight contact with the bare chassis metal.

 

3) Amplifier ground. Grounding a single amplifier should be a simple proceedure. Use a ground wire of equal or greater gauge than your amps power wire and ground it in the same fashion as mentioned above. When using multiple amplifiers you can use a common grounding point. This can be accomplished by the use of a ground distribution block where you connect the grounds of each amplifier to the block, then one wire of equal or greater gauge than your primary system power wire to a single grounding point. The key here is to make sure that the resistance of the grounding point is equal for all amplifiers. Some systems are more prone to noise than others. When you use a distribution block the ground currents of one amplifier may affect ground reference voltage of another causing the more power amplifier to dominate the ground. To eliminate this possibilty ground all amplifiers with their own connection to the chassis at points with 1/2 to 1 inch of each other otherwise the return currents that flow through the chassis may produce a noise voltage between the two points.

 

4) Capacitor ground. I will not address the whys and why nots of adding a cap to your system, that is another issue. The idea here is to treat the capacitor ground the same as you would an additional amplifier. Ground wire of equal or greater gauge than the power wire supplying the cap grounded to the distribution block or common grounding point as your amp or amps are grounded.

 

5) Additional component grounds. When you add processors, EQ's, DVD's, etc you need to keep in mind that by introducing them into your system you add the possibility of creating additional ground loops. They must be grounded with the same principles in mind as you would use in grounding the amplifier or head unit. It is okay for low-current components to share a common grouding point.

 

An important thing to keep in mind is that not all metal in a vehicle is electrically connected to the chassis. The frame or subframe is probably isolated from the chassis with rubber grommets and the connecting bolts may not be touching bare metal. The goal here is to ground everything back to the chassis using ground points of equal (or to within .25 ohms) resistance. If you are unsure of the resistance of a grounding point you can pre-test your grounds using a multi meter. Ideally you are looking for net values of less than 0.3 ohms. Use the battery negative as a reference and start by using a wire (any size will do) that is long enough to reach from the battery to the spot you want to test. Set your multi meter to ohms and measure the resistance of the piece of wire from end to end. Connect one end of the wire to the negative terminal of the battery and the other end to one of the probes on your meter. Use the other post of the meter to test potential grounding spots and write down the ohm readings of each spot. Subtract from that reading the resistance of the wire you previously measured and use the spot with the lowest resistance. You can check several spots and only ground in locations that are within .25ohms of each other if you have to use multiple grounding locations.

 

Finally we will address the issue of Induced Noise. Induced noise has a variety of causes. Induced noise is very sneaky. Sometimes it gets into your system through the power wire, other times it may sneak into the system via adjacent wires or other electrical components through electromagnetic interference (EMI). Here are a few ideas to help eliminate the sources of induced noise.

 

1) Power wire. It is commonly accepted that you run your primary power wire down one side of the vehicle opposite your RCA and speaker wires. You also want to run your remote turn on wire on the same side as your primary wire. The high current in the power wire creates a magnetic field that can induce noise into other wires in close proximity. Some consider this one of the false myths in car audio but in my opinion it doesn't hurt anything to play it safe and isolate the power wire.

 

2) RCA cables. It is not necessary to run out and spend big bucks on RCA's. Just make sure they are well insulated and have connectors that will make good snug contact when they are plugged in. Simple UTP cables (Unshielded Twisted Pair) are usually the best for car audio. It is OK for them to cross the power wire, just don't run them side by side. Install them in a way so they don't become pinched or cut. You may need to trim off excess cable and re-install the connectors to get them to fit. Excess cable laying around will induce loop noise. If you are using a 4 channel amplifier with 2 sets of RCA's you want to twist the two cables around each other from the HU to the amp. Ideally you would want to use a set of 4 channel (UTP) cables for 4 channel amplifiers to prevent loop noise from working its way in between the two sets of cables. If using an EQ or active crossover, do the same twist the cables from the HU to the component, then again from the component to the amplifier. One other thing to look out for is that some of your quality cables have large covers on the terminals that may need to be removed. If the connector cover comes into contact with the chassis of the amp, EQ, active crossover, etc. it will create a ground loop and introduce noise.

 

3) Speaker wires. Once again, it is not necessary to go overboard here either. A good quality 16/18 gauge for your speakers or crossovers and 12/14 gauge for sub woofers is all you need. Run them down the same side as your RCA's away from the power wire and install them in a manner that they don't become pinched when you put your vehicle back together.

 

4) Crossovers. These are one of the sneaky sources of induced noise. The inductors inside passive crossovers will pick up RFI. Keep them away from computers, blower motors, ignition wires, and each other. They will cross talk. You have to experiment with mounting locations to find the optimum location. Different crossovers have different size inductors so they can pick up different amounts of noise.. some can be mounted inches apart, some need half a foot or more. A simple way to test the crossovers is to connect a small speaker to the speaker output terminal on the amplifier and see if the noise is still there. If there is then the crossovers are OK and your problem exists somewhere back up the line.

 

5) Level Matching. Level matching helps eliminate hiss. The manufacturers have provided level controls to allow the sensitivity of the unit to be adjusted to suit the requirements of the installation. Picking the proper operating level for a device gives you the best compromise between noise and headrom. In the case of a head unit and a power amplifier, you want the output of the head unit to be high enough to still give reasonable headroom, while being as far above the noise floor as possible. From the amplifier's standpoint, the level control (or gain) should be set so that the amplifier is just short of clipping. Check out the post under amplifiers for proper gain setting to get more information on how to properly match the gain of your amplifier to the output of your head unit. You must also operate your amplifiers within acceptable resistances so they can produce their power effectively without clipping or overdriving the components they are powering.

 

6) Ignition Wire - There are times when noise can be introduced into the HU through it's power supply. A simple check would be to connect the HU power wire directly to the + battery terminal and bypass the ignition. If the noise is eliminated then you can put a switch on the wire and use it or go to www.davidnavone.com and purchase a power wire choke or filter to install on the power wire.

 

Finding the Source. If you have done all of the above and still have noise you need to find the source. You can accomplish this by making a set a muting plugs. The web site listed above has a tutorial at the bottom of the page for making and using muting plugs. Take an old pair of RCA terminals and clip them off close to the end. Then take the + and - wires coming out of the plug and connect them together. Start at the amplifier and plug them into the RCA imputs. If the noise goes away then you have eliminated the amplifier, speakers, speaker wires, and crossovers as the source. If it is still there you need to check the amps ground, position of the crossovers, the intergrity of the speaker wires (crimped, or the wire may be exposed somewhere and touching metal) and the connection to the speaker. You can also connect a test speaker directly to each channel of the amplifier. If the noise is still present at the speaker located at the amplifier then you will know that the amp is the noise source. If the noise disappears then work your way back to the next component (EQ, active crossover, etc) then finally to the HU, checking the grounds along the way. If you isolate the HU as the source re-check the HU ground. You may find that the noise is being introduced through the power source. If that is the case try switching to a different source or connect the HU directly to the battery. You may even want to connect it to a battery not connected to your vehicle. You may also want to relocate the HU back to the amplifier using a set of jumper wires connected to the battery for your power and ground. Connect the remote wire and a short set of RCA's and test the HU at the amplifier. If the noise is still there then you will know that the problem is internal in the HU and it will need to be repaired or replace. If the noise goes away then the cabling or HU ground is defective. Finding and isolating system noise can be a cumbersome and time consuming affair. Hopefully this information will assist you in eliminating system noise.

 

Well there you have it, my contribution to helping you have a clean and (relatively) noise free install. The information contained in this post is a compilation from various articles from noted experts in the automotive audio field, interviews with audio experts, imput from competition level installers, and personal install experience. It is not intended to be the definative source for all noise issues. If the above suggestions do not eliminate your noise problems then I would recommend you take your vehicle to a professional install shop for more detailed troubleshooting and corrective action. You can also PM me if you have any specific questions. I welcome any additional ideas to this post... Happy Booming to all!!

[KimNK]

Sikker på at det ikkje er litt kabelrot baki bilen?

Hos meg låg strømkabelen surra rundt signalkabelen baki slik at det blei støy, siste eg tenkte på. =P

[Morel]

Husk at det spiller en stor rolle HVOR på karosseriet du fester jordingen fra spilleren!

5624527[/snapback]

Har lokasjon betydning eller er du good-to-go så lenge du finn eit punkt på karosseriet og fjerner litt maling?

 

Er det dårligare jordforhold i ramma rundt spelaren enn andre stader?

5624671[/snapback]

Det finnes som regel en plass å skru fast kabelskoen inni dashen.

 

Metallramma som spilleren sitter i skal ALDRI brukes til jording!

 

Mvh

Pål

[danjohan]

Et strømfilter er ingenting annet enn et plaster, og vil aldri bli det. Lar man være å kutte seg, vil man heller ikke ha behov for plaster. Dersom ting er gjort riktig skal det ikke være behov for et strømfilter, så enkelt er det 

 

PS: hvordan får man biler til å brenne av dynamostøy? 

5624103[/snapback]

 

 

Hvordan man får en bil til å brenne av dynamostøy? Hehe.. Hakke peiling.. Det eneste jeg veit er at først så døde alt det elektriske i volvon, og så fixet vi det.. Så etter en stund igjen skjedde det samme, men da begyte det å brenne i det elektriske under cd spilleren.. Hvordan det går veit jeg ikke Det skjedde i hvertfall >_<

[kpolberg]

Hvordan man får en bil til å brenne av dynamostøy? Hehe.. Hakke peiling.. Det eneste jeg veit er at først så døde alt det elektriske i volvon, og så fixet vi det.. Så etter en stund igjen skjedde det samme, men da begyte det å brenne i det elektriske under cd spilleren.. Hvordan det går veit jeg ikke Det skjedde i hvertfall >_<

5630559[/snapback]

 

Du hadde ALDRI fått rørt noe elektrisk på min bil i hvertfall. Det lille du forteller her, sier noe for min del om hasardiøs omgang med elektriske i en bil. Ikke aner jeg hva du har gjort, men noe seriøst feil må du ha gjort under installasjonen.

[danjohan]

Hvordan man får en bil til å brenne av dynamostøy? Hehe.. Hakke peiling.. Det eneste jeg veit er at først så døde alt det elektriske i volvon, og så fixet vi det.. Så etter en stund igjen skjedde det samme, men da begyte det å brenne i det elektriske under cd spilleren.. Hvordan det går veit jeg ikke Det skjedde i hvertfall >_<

5630559[/snapback]

 

Du hadde ALDRI fått rørt noe elektrisk på min bil i hvertfall. Det lille du forteller her, sier noe for min del om hasardiøs omgang med elektriske i en bil. Ikke aner jeg hva du har gjort, men noe seriøst feil må du ha gjort under installasjonen.

5630897[/snapback]

 

 

Hehe.. Dem sa på verkstedet at det ikke var våres skyld, men at det var dynamostøyet som var grunnen!

 

En annens kompis 740 begynte jo å brenne bare fordi han kjørte på et esso skilt i 15 kmt.. Knuste venstre blinklys bare.. Grunnen til at den brant var fordi den ene ledningen hadde liggi i klemme bak.. Sa snuten i hvertfall