chrishill 0 Posted November 9, 2003 I've just installed a 4channel amp and a 12" sub, i'm running that along side some 6x9's (off the amp) and some dash speakers. The dash speakers had been fine up until i put the amp in, now when its up fairly loud they pop and crackle in a horrible way! Adjusting the ballance all the way to the front seems to sort them out, and they seem much much better with the engine off. Also, the display on the headunit dips in time to the music (funky!) which obviously cant be good. I've had a smaller sub/amp setup in the car before and had no simular problems so does anyone have a clue?? Do you think i need a bigger battery? Quote Share this post Link to post Share on other sites
dr_mat 0 Posted November 9, 2003 I think you need a smaller amp... Or a bigger alternator... ;) Quote Share this post Link to post Share on other sites
G60JAY 0 Posted November 9, 2003 It sounds like the cables supplying your amp are a too small. Quote Share this post Link to post Share on other sites
chrishill 0 Posted November 9, 2003 well the amp itself is rated at 600w max over the 4 channels, thinking about it you might be right about the wires, i cant remember what power rated wiring kit i got but i know it was fairly low as my old amp was only 150w.... but would that effect the headunit-driven dash speakers as they're the ones playing up? Quote Share this post Link to post Share on other sites
stevemac 0 Posted November 9, 2003 well the amp itself is rated at 600w max over the 4 channels, thinking about it you might be right about the wires, i cant remember what power rated wiring kit i got but i know it was fairly low as my old amp was only 150w.... but would that effect the headunit-driven dash speakers as they're the ones playing up? 600w amp wiring kits are not readily available - go to Maplins, tell them the output of your amp and they will make a kit up for you. You will need to use at least an 8 gauge (with 40 amp fuse) permanent live power feed direct from your battery. Any smaller than 8 gauge on a 600w amp is a fire hazzard - your car may set on fire as the cable will get very very hot. I would change this immediately !! Take the switchable live feed for the amps from the electric aerial connection on the back of your head unit. Thin cable is okay for this switchable live as all it does is send a pulse of power when the head unit is turned on & another pulse when it is turned off. Most ICE suppliers do not stock wiring kits rated above 400w. Your dash speakers may have reached the end of their lifespan - maybe time to change/uprate them Battery should be okay - I'm currently running a 480w 4-channel amp, a 200w 2-channel amp (bridged) and a 4x50w head unit, all powering a total of 12 speakers. I have no problems at all !! Quote Share this post Link to post Share on other sites
chrishill 0 Posted November 9, 2003 Your dash speakers may have reached the end of their lifespan - maybe time to change/uprate them I'm running some good little pioneer's up front which i bought about 2 months ago, so they should be ok, rated 75w RMS running off the headunit which is 4x50w. Found out the wires i have are rated up to 300w, probably 4 gauge? I can get 8 gauge for about £3 a metre, and i already have the other bits from my other amp like the switchable live, so I'll give that a go first :) 12 speakers steve? sounds like you've got an impressive setup there! 8) Quote Share this post Link to post Share on other sites
copierbw 0 Posted November 9, 2003 Would my assumption be right in saying you have 2 channels bridged to power the subwoofer. The second pair on the amplifier are connected to the 6'X9' individually. Where did you connect the dash speaker to? If on the amplifier did you also connected them to the 6'X9' channel did you || (par) or = (ser) them. What is the RMS rating on the speakers on the dash, ohm rating? I have a idea the dash speakers are being clipped (not being able to handle the power given to them). That sound is normally heard when they are being played out of their power capability range and the sine wave turn into a block wave and the speaker starts to bottom, heat their coils and eventually after long hours of play burns the coil or goes open circuit.. Quote Share this post Link to post Share on other sites
Joe M 0 Posted November 9, 2003 The display on the headunit dims with the music, wouldnt this mean a powercap would be beneficial? :? Quote Share this post Link to post Share on other sites
copierbw 0 Posted November 9, 2003 That might be a solution if he has the amp is bridged down to a very low ohm rating like 2 or lower (with loads of amp's and subs in the boot) and the surge from the amp is too much and faster than what the amp can deliver from it's own internal stiffening capacitors. But on the other hand you will always have a slightly dimming head unit even if you overfeed the head unit with a higher voltage or 20 stiffening capacitors. It is hard to tell how much his head unit are dimming and I guess the perfect answer would only be possible if we guys knew exactly what his setup looked like from the head unit rating down to the amp... :D Quote Share this post Link to post Share on other sites
stevemac 0 Posted November 9, 2003 Found out the wires i have are rated up to 300w, probably 4 gauge?Sounds more like 10 gauge - 4 gauge is more likely to be used in a power station. i already have the other bits from my other amp like the switchable liveCheck where the switchable live is taken from - could be part of your headunit dimming problem. Move it to the electric aerial connection on the back of the headunit. 12 speakers steve? sounds like you've got an impressive setup there! 8)Yeah - I've got 3 dash tweeters, VIBE component 160w front door speakers (tweeter + mid bass in each door), VIBE 6x9 300w rear speakers in a custom built MDF shelf, factory rear speakers connected to head unit & 12" sub. :rambo: chrishill - just a thought, is the sound signal supplied to your amps via RCA leads or speaker outputs ?? Quote Share this post Link to post Share on other sites
copierbw 0 Posted November 9, 2003 This is what I love the most about this forum...Everyone tries to help... :lol: Cheers stevemac Quote Share this post Link to post Share on other sites
stevemac 0 Posted November 9, 2003 This is what I love the most about this forum...Everyone tries to help... :lol: Cheers stevemac Cheers m8 I was quite fortunate when I fitted my stuff - one of my mates is a professional sound engineer. He just made a few cups of tea for me while I fitted my stereo.. :lol: :lol: Quote Share this post Link to post Share on other sites
andycowuk 0 Posted November 10, 2003 rated 75w RMS running off the headunit which is 4x50w. This is the answer to why the front speaks sound poor the 4x50w quoted for your head unit is probably pmpo (at best!!!). Quote Share this post Link to post Share on other sites
stevemac 0 Posted November 10, 2003 rated 75w RMS running off the headunit which is 4x50w. This is the answer to why the front speaks sound poor the 4x50w quoted for your head unit is probably pmpo (at best!!!). For example - rather than using the RMS voltage of the amplifier output which might be 12.6 volts driving the 8 ohm speaker, PMPO uses the peak voltage (17.9 volts) and works out power this way: (17.9)(17.9)/8 = 40 watts. And then both channels are added together: 80 watts. Sounds high-power in the advertising, but in actual practice is misleading Most amplifiers will begin to distort the sound output signal long before the rated maximum power output is achieved, this distortion is the main cause of speaker damage. chrishill - if you aren't using RCA leads then get some. Turn up the gain controlls on your amps, maybe to 75% of maximum - this will mean that for a given volume, your dash tweeters will not have so much distortion from the head unit to cope with. Quote Share this post Link to post Share on other sites
chrishill 0 Posted November 10, 2003 Would my assumption be right in saying you have 2 channels bridged to power the subwoofer. The second pair on the amplifier are connected to the 6'X9' individually. Thats right mate, and my dash speakers are running off the original wires directly from the headunit. 4 gauge is more likely to be used in a power station. :oops: probably not then! hehe Check where the switchable live is taken from The headunit has a specific connection for amp swichable power, so its off that. if you aren't using RCA leads then get some yeah i'm running RCA's, turning the gain up on the amp sounds like a good plan, I never realised that running high RMS rated speakers off a low rated source could cause problems, i assumed (obviously wrongly!) that so long as the RMS was higher on the speakers i'd be fine. Cheers for all the help and advice, as copierbw said, this is one of the great things about this fourm! very much apreciated everyone! Quote Share this post Link to post Share on other sites
stevemac 0 Posted November 10, 2003 No problem m8 - just added a technical paragraph into my earlier post - may help explain the differences in output measurement for you. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted November 10, 2003 For example - rather than using the RMS voltage of the amplifier output which might be 12.6 volts driving the 8 ohm speaker, PMPO uses the peak voltage (17.9 volts) and works out power this way: (17.9)(17.9)/8 = 40 watts. And then both channels are added together: 80 watts. Sounds high-power in the advertising, but in actual practice is misleading And not only this, but the quoted figure is often measured at some ludicrous level of distortion (10%+) by which point you'd hate the sound so much you'd already have turned it down. Proper hifi is measured at 0.1% distortion (or lower). My Cyrus amp has a rated 60W/channel RMS but at 0.003% distortion... Very clear and clean!! :) Quote Share this post Link to post Share on other sites
dr_mat 0 Posted November 10, 2003 Oh, and they often use a 1kHz sine wave, which is nice and EASY to reproduce, whereas proper hifi is rated with white (or pink) noise - a wideband noise to really test the system bandwidth under load. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted November 10, 2003 Oh, and they often use a 1kHz sine wave, which is nice and EASY to reproduce, whereas proper hifi is rated with white (or pink) noise - a wideband noise to really test the system bandwidth under load. By the way, for all the information I can spout here, I just have the factory-fit tape unit with the factory-fit speakers in my C, and 99% of the time I even leave the fascia at home when I go for a drive... The engine is the best noise you can make in a VR6.. ;) Quote Share this post Link to post Share on other sites
chrishill 0 Posted November 13, 2003 well, problem solved! I ended up taking it to a specialist, mostly becuase i needed it sorting quickly and i dont have the time at the moment, he sorted it in about 20mins, loose wire behind the headunit! sounds blummin' lovely now! ....off to annoy the neighbours :twisted: Quote Share this post Link to post Share on other sites
dubster82 0 Posted November 13, 2003 rated 75w RMS running off the headunit which is 4x50w. they arent actually getting 50x tho, 50w isnt an rms rating, and the ratings of units make em sound really weedy. so they quote max, or higher with dumb equations. Quote Share this post Link to post Share on other sites
chrishill 0 Posted November 14, 2003 yeah, i know they'll be getting way way below the RMS they're capable of, eventually i'll amp them! Quote Share this post Link to post Share on other sites
