bronco91shee Posted April 20, 2004 Report Share Posted April 20, 2004 igot a 280watt rockford amp tht used to run 3 pairs of tweets. i had it runnin on high pass right from my deck, no rca's. i had bass blockers in and they worked good, until i blew them up. now i have a good set of pionners and one other cheap set on the same amp. everything still set up the same. now after like 30mins, the amp over heats and shuts off. my bro thinks its cuz im runnin my deck amp(40 watt) into my other amp, then to my tweets. so i ran my amp on low pass, and it doesnt over heat, but it gets so much engine wine, i cant hear the music. i have rearan teh wires a few times, it dont help. could it be that i am just tryin to push to much w/ these new tweets? maby did i wire them wrong, i think its in series? any help would be great, cuz i know more htan all my freinds bout this stuff, and i cant figure it out. and have no one else to ask. the stero shops dont really know either. any help or thoughts would eb great. come on u eletronic bro's. peace out, and thanks for ur help in advance Quote Link to comment Share on other sites More sharing options...
boonman Posted April 20, 2004 Report Share Posted April 20, 2004 igot a 280watt rockford amp tht used to run 3 pairs of tweets. i had it runnin on high pass right from my deck, no rca's. i had bass blockers in and they worked good, until i blew them up. now i have a good set of pionners and one other cheap set on the same amp. everything still set up the same. now after like 30mins, the amp over heats and shuts off. my bro thinks its cuz im runnin my deck amp(40 watt) into my other amp, then to my tweets. so i ran my amp on low pass, and it doesnt over heat, but it gets so much engine wine, i cant hear the music. i have rearan teh wires a few times, it dont help. could it be that i am just tryin to push to much w/ these new tweets? maby did i wire them wrong, i think its in series? any help would be great, cuz i know more htan all my freinds bout this stuff, and i cant figure it out. and have no one else to ask. the stero shops dont really know either. any help or thoughts would eb great. come on u eletronic bro's. peace out, and thanks for ur help in advance Alright. You say you were feeding it "high pass" w/ no RCA input. I assume this to mean high level input. High pass would be a crossover term, meaning that anything OVER the listed frequency passes, and anything lower than the listed frequency does not. now, that is what the bass blockers are. They are a high pass crossover. On a high level input, (speaker level input it is also called) power input, (or output from the deck, or the "source") does not matter. The amp will only take the signal, because you aren't actually powering a speaker. I can't figure out in gods name why anyone would want this type of signal. It is horrendous. Now, you also say you were running 3 pairs of tweeters. Tweeters require a clean signal. You can't feed them distortion, they can't handle it. Distort a signal to a tweeter, and it will blow. Feed any speaker enough distortion, and it will blow.... Now, this can be looked at two ways. You can still have the 3 pairs of tweeters in there, and added a set of pioneer something or other, and added another pair of "cheap" speakers as well. This gives a total of five speakers. If this is the case, that is a TREMENDOUS load if you are wired parallel. I assume you are parallel, because that is how 80% of people will wire something. Each "extra" speaker in line on a parallel connection, cuts the resistance load in half. SO, if all the speakers are 4 ohm, (as is all car speakers are 4 ohm, except a JL audio W-6 and some others I'm sure that are 6 ohm and other wierd numbers, but anyways) you will have a load seen by the amp as 1/4 ohm. That is hellacious, on any amp. And will overheat it very quickly. Now, the other way to look at the scenario. You got rid of the 3 pairs of tweets, and now have the pioneeer, and the cheapo pair. This would be a 2 ohm load if wired in parallel. Don't worry, I'll give you the rundown on parallel vs. series in a minute.... BUT, if you are now pushing frequencies below, let's say 150 hz, which would have been previously blocked out by the bass blockers, you will be heating up the amp more.... That rockford amp should have a built in crossover. Now, you say wen you ran that amp on "low pass", you got engine whine. I assume this to mean low level input, Or RCA input. This can be one of two things. Either a bad pair of RCA cables with improper shielding or some problem with the cable itself. Get a good set of cables. They are worth it. Trust me. Or, it could be a ground problem. if you're amp isn't grounded properly, you will get hellacious alternator noise. One ting often overlooked, is the ground strap from the battery tto the chassis. On a factory vehicle, this is very small. Say you're running 4 guage or larger power to your amp(s), you need to upgrade this wire. They are usually 8 guage or smaller. Alright. Parallel vs. Series connection: For simplistic matters, we will only talk about one channel here, so we only have to deal with a +, and -. Or, positive, and negative. Parallel- A parallel connection hapens when you come off the amplifier terminals, and go to the speaker terminals. So, you have positive to positive, and negative to negative. Now, for the next speaker, you come off the positive of the first speaker, and go to the positive of the second speaker. And the same for the negative side. And so on and so forth. So that all the positives are connected together, and all of the negatives are connected together. This drops the load in half for every speaker that is connected. Remember, you start with 4 ohms out of the amp.... first speaker is 4 ohm. Next one goes to 2 ohm load. Next one goes to 1 ohm load. Series- Here's where things can get tricky. You come off the amp positive terminal. Take that to the first speaker positive terminal. Now, run a jumper from the speaker positive terminal to the negative terminal on that same speaker. Now, off of that negative terminal, run a wire to the positive terminal of the next speaker. Take a jumper from that positive terminal, to the negative terminal of that speaker. Then, you can either go from that negative terminal, to another positive terminal of the next speaker, or if there are no more speakers to be installed, you take a wire back to the negative terminal of the amp. Get the jist here? Now, remember that in a series connection of speakers, your load doubles. So, your 4 ohm initial load becomes an 8 ohm load. And so on and so forth. Power wise, in a parallel connection, each time you put another set of speakers in there, and drop the witnessed load seen by the amp, you usually about double your power, or close to it. HOWEVER, not many amplifiers are stable below 4 ohm, or 2 ohm. Especially the cheaper ones. A rockford amplifier, depending on the series of that amp should be stable to 1 ohm. Some are stable to 1/2 ohm. In a series connection, when you double the load for every speaker connected, your power out gets about cut in half. Theoretically. A series connection will let everything run cooler. Especially your amp. You see, when running parallel, it will heat things up considerably. SOmetimes, this must be taken into account. Also remember, that as son as you bridge a bridgeable amp, they usually drop automatically to a 2 ohm load. So instead of starting out at 4 ohm, you are now starting at 2. So, if you bridge an amp to drive a subwoofer, and you wire 2 4 ohm subs in parallel, you are at a 1 ohm load. See???? The tricky part comes in stereo competitions where wattage classes are concerned. You may have an amp that is rated at 25Wx2 when run in 4 ohm stereo. BUT, bridge it down to 1/4 ohm mono, and you may be pushing 1,000WRMS??? Sick numbers. And those amps are pricey. 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blazenlo Posted April 20, 2004 Report Share Posted April 20, 2004 Also, I'm not sure if this was said buy boonman in his 10 page reply but make sure your ground wire going to your amp is as short as it possably can be.( preferably 2-3 feet. Hope you get it all figured out. Quote Link to comment Share on other sites More sharing options...
boonman Posted April 20, 2004 Report Share Posted April 20, 2004 Did i forget to leave that out???? Sorry.... lol EXCELLENT point though. Long ground lead can cause you Quote Link to comment Share on other sites More sharing options...
sredish Posted April 20, 2004 Report Share Posted April 20, 2004 I would imagine it would be the load going to the amp. Mixing and matching spkrs is cool as long as the speakers have the same resistance and you end up with the proper load for the amp. Quote Link to comment Share on other sites More sharing options...
BrokeStonedBiker Posted April 20, 2004 Report Share Posted April 20, 2004 why would you run an amp to tweeters? also i dont know if this was mentionent in the 20 pg reply but. make sure your speeker cables are not runnig the same grounds as your power cable.. that will make it sound like a lear jet is taking off when you hit the gas. or maybe its the RCA's that do it, or both. maybe boonman will know. good luck. some one said your mixing and matching going to the same amp? not a good idea. and cut down on the watts going to the amp, just because they say there 200 watt amps doesnt mean thats what they do. thats there peek power, right before the fuckin thing melts and starts your truck on fire they call out that thats the PP. i dont know to much about electroics mu self but thats what i do know. good luck Quote Link to comment Share on other sites More sharing options...
BrokeStonedBiker Posted April 20, 2004 Report Share Posted April 20, 2004 oh yeah how many channel amp is that? Quote Link to comment Share on other sites More sharing options...
bronco91shee Posted April 20, 2004 Author Report Share Posted April 20, 2004 yeh, i have tried different rca's smae problems. i have run the rcas toataly apart from everything else in the dam truc. it only does it on my front amp. my rear 2 amps for my subs play just fine. it is a 2 channle amp w/ the built in crossover. i ran the amp, cuz i plan on runnin my regular front speakers off my deck, and dint wanna over power my deck w/ those speakers and my tweets. right now i have only the one good pair of tweets and the other cheap pair. nothin else, not even the regualr front speakers yet. and i do understand series and parallel, cuz im an auto tech student in college. btu thanks so much for all the reply. it makes sense. i think what i did wrong was i ran the wires in parrallel at the amp, then where the tweets are mounted i ran them in series. that would put a huge load on it right? that explains why my amp is turned down all the way on gain, b/c if i turn it up at all, it distorts quickly. ill try changin the wires when i get home this weeknd. yeh, i figured between the high pass and the bass blockers, there would be like nothin but highs goin to the tweets, was i wrong there? that makes sense, cuz i think it was after i ran them in parral that i blew out my last pair. i should have never messed with it. thanks so much, and ill let u know what happens. if anything i have said here gives u more thoughts, please fill me in. peace out Quote Link to comment Share on other sites More sharing options...
PUSH THE THROTTLE Posted April 20, 2004 Report Share Posted April 20, 2004 BrokeStonedBiker I've had a Rockford Fosgate amp before and the rating on the amp was the rms, they even come with a sheet that shows what the peak wattage is example: mine was a 600 watt amp peak was 820. But I do agree "most" companies only show peak wattage numbers my first amp was a pyramid 300 it definately wasn't putting that out. Also I don't know if all Fosgates are labeled by rms I would assume some of there cheaper models are probably labeled with peak. Quote Link to comment Share on other sites More sharing options...
blazenlo Posted April 20, 2004 Report Share Posted April 20, 2004 Every amp will have peak watts and rms. You allways go by the rms watts. Quote Link to comment Share on other sites More sharing options...
banshee04le Posted April 21, 2004 Report Share Posted April 21, 2004 Driver impedances do vary (although most are 4ohm) so we are really just guessing as to the load being seen by the amp with the current information you have supplied us. If you don't have an ohmmeter, get one and measure the load at the amp (bypass your bassblockers for an accurate reading). Check all of your speaker wires to ground with the ohmeter and make sure they are not grounded (don't check them while they are connected to the amp or you will measure to ground). On the noise issue, insure the chassis bonding by upgrading the groundstrap as boonman said. Make sure the head unit is grounded really good and then make sure you are using a shielded rca. Cheap ones are not shielded worth a piss. A good rca cable will have direction arrows on it. The arrows should point from source to amp. Fail to note this and install it backwards and you will be dumping all of the noise to the amp instead of back to the properly grounded source as it should be. Oh, and friends don't let friends drive distortion. Turn your gains all the way down, turn your head unit all the way up (if it is a good one, otherwise back it down a couple notches) and then slowly raise the gains as much as you can...but don't drive distortion, I hate that . Quote Link to comment Share on other sites More sharing options...
bronco91shee Posted April 21, 2004 Author Report Share Posted April 21, 2004 thanks for al the help yo. ill try that stuff this weekend. yeh, i got a blue point(350) meter. so i think im good. peace out Quote Link to comment Share on other sites More sharing options...
boonman Posted April 21, 2004 Report Share Posted April 21, 2004 make sure your speeker cables are not runnig the same grounds as your power cable NEVER chassis ground a speaker. You could also be getting noise from the head unit and it is just feeding a noisy signal tto the amp. You aren't getting it throught the high level input possibly and the RCA connection feeds it through. Low voltage RCA outputs can be finnicky. All the kmore reason to go with a better head unit with a higher voltage output. Cleaner signal. And shielded RCA's are the ONLY way to go. Like I mentioned before, they are worth more than their weight in gold... If they don't cost you at least $40, they aren't worth a shit...... And yes. I have often wondered why I haven't printed up some distortion tickets to hand out around here. Every time I roll up to the stop light, and some crackhead in his beat up Honda Civic is bumping his 12" beat missers and crackling the shit out of his mids and tweets I want to and they want to Sorry buddy. It just ain't workin. Back to the drawing board. Power doesn't kill a speaker. Distortion does...... Quote Link to comment Share on other sites More sharing options...
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