WildPlumDx Posted March 11, 2009 Share Posted March 11, 2009 ok i toally have no idea about car audio but i have a head unit pioneer one with one rca only and i have 2 sets a fusion 6.5 components one in front one in rear, just wondering if i would benefit from an amp much with the set up and was looking at those cheap v12 amps on trade me as i'd need a 4ch amp correct ? will i be able to run this off a headunit with one rca ? would it even be worth amping my speakers? Quote Link to comment Share on other sites More sharing options...
Yowzer Posted March 11, 2009 Share Posted March 11, 2009 An amp (that isn't complete dirt crap) will give better audio quality than running on the headunits internal amp. Especially at the lower frequencies. Yeap ya can run both front and rear off the single rca output, but you won't be able to adjust the balance between front and rear from the headunit. Not that thats a real problem as the amp has individual gain adjustments anyway. Quote Link to comment Share on other sites More sharing options...
WildPlumDx Posted March 11, 2009 Author Share Posted March 11, 2009 sweet, so might be better buying a second hand name amp ? what about this one http://www.trademe.co.nz/Trade-Me-Motor ... 939240.htm oh and can u get to much power from an amp and blow speakers ? like 1400watts seems heaps from those cheap ones Quote Link to comment Share on other sites More sharing options...
von Mako Posted March 11, 2009 Share Posted March 11, 2009 like 1400watts seems heaps from those cheap ones And it would be if they actually made that much. If you bench tested one, I doubt you'd even see half that power. I'd definatly go for the Xplod amp over that V12 crap. You'll need some RCA splitters to run the 4 channel amp, but they're pretty cheap. Other option is amp your front speakers with a 2-channel amp and run the rears off the headunit Quote Link to comment Share on other sites More sharing options...
LAN_KILLA Posted March 11, 2009 Share Posted March 11, 2009 Agreed with above... When looking at amps dont look at the Max/PMPO Wattage as this is a more or less bullshit figure they pulled out of thier ass to make thier stuff look good, but unfortunately all manufactures list it. Look at the RMS/Rated Wattage, Take that sony one for example Maximum (14.4V): 4 Ch x 100W at 4 ohm Rated / THD (14.4 V 20 Hz - 20 kHz): 4 Ch x 50W at 4 ohm (0.04% THD) The Rated figure is the one to be looking at here, try and get the rated figure as near as possible to the rated figure on the speakers As said you will need to get some splitters to run both channels, although some amps do have a RCA input and output off Ch1/2 which you can then loop the output into the input of Ch3/4... But which amp you get will dertmine what you do Quote Link to comment Share on other sites More sharing options...
Yowzer Posted March 11, 2009 Share Posted March 11, 2009 sweet, so might be better buying a second hand name amp ? what about this one http://www.trademe.co.nz/Trade-Me-Motor ... 939240.htmoh and can u get to much power from an amp and blow speakers ? like 1400watts seems heaps from those cheap ones The main destroyer of speakers is 'clipping' (when the amp can't supply enough power to complete the waveform, and ends up cutting the tops off), so it's actually better having an amp more powerful than the speakers. Also if ya have the crossovers set up right ya can generally pump more power into the speakers without a problem anyway. On an unrelated side note; I ran a 25W speaker on my 1000W RMS amp. It set on fire Quote Link to comment Share on other sites More sharing options...
WildPlumDx Posted March 12, 2009 Author Share Posted March 12, 2009 sweet also what about sub cables and junk so many to chosse from on trade me whats the best to go with ? might just buy the sony 500w should be enuff power aye ? also i dont think that amp has all those little dials for adjusting bass etc do u need that stuff ? Quote Link to comment Share on other sites More sharing options...
WildPlumDx Posted March 12, 2009 Author Share Posted March 12, 2009 also what are ohm's is that only sub related ? Quote Link to comment Share on other sites More sharing options...
84_S12 Posted March 12, 2009 Share Posted March 12, 2009 http://www.jaycar.co.nz/productView.asp?ID=AA0480&CATID=24&form=CAT&SUBCATID=619 Use these lnline from speaker level output (It's an attenuator so will drop it down to line level for amplifiers) and run RCAs from these to AMP Assuming you have 4 speaker outputs and a 4 channel amp, then you have RCA outputs free to run a sub from same headunit Quote Link to comment Share on other sites More sharing options...
Thousand Dollar Supercar Posted March 12, 2009 Share Posted March 12, 2009 also what are ohm's is that only sub related ? Ohms are the units that electrical resistance is measured in, like how you measure current in amps, distance in metres etc. Every speaker has a resistance (sometimes called impedance instead), and common values are 4 ohms or 8 ohms. As far as I know, all you have to watch out for is that you don't connect a 2 ohm speaker to an amp only designed to drive speakers of 4 ohms or higher, for example. Also, everyone seems to have assumed the single RCA output is the only output from your head unit. That would be a weird head unit, only capable of working in mono! The RCA might be the subwoofer output, and it might only send out low frequencies. In that case you don't want to use it to drive anything other than an amp which will power a subwoofer. Some of the other wires from the headunit will probably be for connecting to normal speakers, through an amp if you want though not required. Quote Link to comment Share on other sites More sharing options...
Ned Posted March 12, 2009 Share Posted March 12, 2009 you can put 8 Ohm speaker on 4 Ohm output, not other way around. Just keep that in mind and you'll be sweet. Can get around by doing 2 4 Ohm in series to create 8Ohm ( 4+4 = 8 ) or two 8 Ohms in parallel to get 4 Ohm ( 8/2 = 4 ) just did a quick google to get more info as proof etc, Click Me Quote Link to comment Share on other sites More sharing options...
forced Posted March 12, 2009 Share Posted March 12, 2009 The main destroyer of speakers is 'clipping' (when the amp can't supply enough power to complete the waveform, and ends up cutting the tops off), so it's actually better having an amp more powerful than the speakers.: 100% wrong.I've read it here before too....... forum BS. Probably started by some FW salesman of speakers to keep the sales going. Then continued by the usual sheep. The speakers should always be rated higher than the amp. Otherwise the voice coils burn up at party time when it gets left at full volume. BTW when you measure speakers with an ohm meter the 4, 2 or 8 ohm is impedence which varies with frequency. The resistance is always less than the impedence. 4 ohm speaker will measure maybe 3.5 or so ohms resistance. Steve. Quote Link to comment Share on other sites More sharing options...
Ned Posted March 12, 2009 Share Posted March 12, 2009 at the end of the day it doesnt matter a great deal about the power (dont shoot me yet guys) just get it roughly right (within sort 25%) and run them so the amp doesnt clip and the speakers dont tun out of travel and you'll be fine. There is no perfect setup. Just dont abuise what you have and all will be fine Quote Link to comment Share on other sites More sharing options...
Yowzer Posted March 12, 2009 Share Posted March 12, 2009 The main destroyer of speakers is 'clipping' (when the amp can't supply enough power to complete the waveform, and ends up cutting the tops off), so it's actually better having an amp more powerful than the speakers.: 100% wrong.I've read it here before too....... forum BS. Probably started and contiuned by some salesman of speakers to keep the sales going. The speakers should always be rated higher than the amp. Otherwise the voice coils burn up at party time when it gets left at full volume. BTW you don't measure speakers with an ohm meter because the 4, 2 or 8 ohm is impedence which varies with frequency. The resistance is always less than the impedence. Steve. You're an idiot. Quote Link to comment Share on other sites More sharing options...
forced Posted March 12, 2009 Share Posted March 12, 2009 The main destroyer of speakers is 'clipping' (when the amp can't supply enough power to complete the waveform, and ends up cutting the tops off), so it's actually better having an amp more powerful than the speakers.: 100% wrong.I've read it here before too....... forum BS. Probably started and contiuned by some salesman of speakers to keep the sales going. The speakers should always be rated higher than the amp. Otherwise the voice coils burn up at party time when it gets left at full volume. BTW you don't measure speakers with an ohm meter because the 4, 2 or 8 ohm is impedence which varies with frequency. The resistance is always less than the impedence. Steve. You're an idiot. You're the idiot. I've spent over 25 years electronics repair business.Needless to say I've repaired several hundred amps and I've seen plenty of toasted speakers. What do you do? Salesman? Going back to when people had "real" amps at home, some of my mates upgraded them with "wharfdale " speakers. I don't know the specs but were considered to be bullitproof. So .... according to your theory running say 120 watt speakers with a 50 watt amp would blow the speakers? Wrong. What would happen is that the coils & cones are a bit heavier so need a bit more power to get them going. That in turn means that you'll have the volume on the amp cranked up a bit higher to get the same sound output.You'll never blow them though. Of course if you leave any amp running at full power for too long it will get hot and start to distort....... the amp might blow up, but then if it's a good amp it willl have protection circuits in it. If the speakers are rated lower than the amp and you do the same thing..... the speaker coils burn, go low resistance then take out the amp as well.....unless it's got protection circuits. Steve Quote Link to comment Share on other sites More sharing options...
Yowzer Posted March 12, 2009 Share Posted March 12, 2009 Hey Steve, when was the last time you ever posted anything actually helpful in a tech thread? Almost every one of your posts is shooting down other peoples ideas or suggestions, and making out that you are some fucking super guru of absolutely everything despite never contributing anything remotely useful, or even on topic for that matter. Running a speaker over its power rating heats the coil up nowhere near as much as putting a constant DC voltage into it, which is exactly what clipping is. Running a higher rated speaker on a lower rated amp means the amp cannot supply enough power to take full advantage of the speakers potenntial, so ya turn the volume up and woops, DC volts into the coil. Bang. Chuck a higher rated amp on and ya can run the speaker happily at full potential with no worry about clipping destroying it. Also, if you're such an idiot that you're gonna run a speaker way over it's capacity, then you deserve to destroy it. No idea how you could stand listening to it though as if the speaker is running over its physical power capacity it will be maxing out the cone throw and distorting like a motherfucker. Especially if you're not running any sort of crossover. I know this shit inside and out. A home amp system works a bit different from a car system. The input signal on a home amp is constant, and the output volume is controlled on the amp itself. On a car, the volume is controlled from the headunit so the input signal is variable. When the volume is turned up too high / gain set incorrectly the amp tries to recreate the waveform yet doesn't have enough output power to complete it, hence the clipping. Quote Link to comment Share on other sites More sharing options...
kyteler Posted March 12, 2009 Share Posted March 12, 2009 Going back to when people had "real" amps at home, some of my mates upgraded them with "wharfdale " speakers. I don't know the specs but were considered to be bullitproof. Steve Sorry Steve, but if you and your mates were big "wharfdale" fans, then that's likely where the problem lies. Quote Link to comment Share on other sites More sharing options...
DB8-TypeR Posted March 12, 2009 Share Posted March 12, 2009 It is always good to have the amp with more power than the speakers rating. Its called headroom. So long as you dont clip the speakers they will be perfectly fine and probably sound better with the extra power (cleaner sound etc) I have 40wrms speakers and have been giving them 104wrms daily for the past 2.5years and they are still as good as the day I got them Quote Link to comment Share on other sites More sharing options...
WildPlumDx Posted March 12, 2009 Author Share Posted March 12, 2009 wharfdale is junk on other news i'm fully lost and 84_S12 what the heck are those things from jaycar ? explain dumb it down for me i have no idea sorry i'm so difficult, will that sony 500w be sweet to run my 4 fusion components ? Quote Link to comment Share on other sites More sharing options...
84_S12 Posted March 12, 2009 Share Posted March 12, 2009 It's like kinking a hose to water your pot plants - it limits the hose pressure so you don't blast them out of their pots So: Wire these into the speaker outputs on your heady's plug-in harness as if they were speakers Run RCA cables from the outputs of these gadgets to your amp Adjust the output level to match the required input level of your amp Connect speakers (Choice option) Connect a single channel amplifier to your now unused RCA outputs Connect subwoofer Doof Doof +Profit Steve you must have been an epic failure as an electronics technician Quote Link to comment Share on other sites More sharing options...
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