sqguy

I don't understand, there is a wire inside the amp? Did it blow the HU too?

Lock up the cables so they can't get out?

I've always had the experience of swapping car amps to change the sound. However I think it is more due to how the amp is colored, or internal EQ'ing, not the output transistors themselves like Clark says. Also different amps go into distortion in different ways; on the high side my little alpine will cut out with bass hits but stays clean otherwise....my new kicker will fade to static no matter what and it does not work for me in this setup. Maybe new amps sound the same but old ones were often different (comparing w/out an EQ change if you even had one). Then you have other things like noise floors, overhead, etc. I will agree you need to find a pretty crappy amp to hear amplifier produced flaws that affect the music in a normal car even if the amp has a slightly different response or 'sound' such as more/less bass response. I made metal tapes for years off of records. They were great in a car, most people never heard a metal tape made on a three head deck.

They just work in A at low volumes, like most class AB do. I doubt you (or me) could tell the difference from a pre buy SS to another far as quality. They might have used other higher quality parts inside not sure, or even colored it a little different, the right tech would know. Class A is marketing in cars, you just can't do much power at all in pure class A. They say some day all car amps will be class D/T/etc.

If you can put ply or mdf over the holes and deadening.

The wire resistance is a factor of distance, so the small wire (that should be much larger than your fuses) going into the amp should not matter unless it gets hot. Just size it up close to the amp. As far as new amps I don't like the type with vertical transistors as some break off but its not that big a deal. I would not mount any of them where they might vibrate, and they are harder to fix if a smaller circuit goes away. Indeed some companies are much nicer to work with as far as support. I've had help from Maxxonics and Lightning Audio they were very nice people compared to some others. Most have the amps made in China and people here know nothing about them or just will not help you, or there is nobody but marketing people here. Some of these companies (cheap amps but now mid level ones too) just toss return amps you see them on ebay all the time, because there is nobody here to do anything with them = zero support. 'Landfill amps' I guess.

I would find out before buying, I have a F100.4 tiny little thing and it only has 12v ICs in it...in other words it has worthless HU amps in it and no power supply. I did not even think anyone made those anymore that is worse than a pyramid. They are $39...but the larger amps I am sure are different.

I always put dielectric compound (grease) on the contacts, has really helped me and can cool it some if you are maxing current in it. It fights corrosion and keeps dust out. I use it on lots of plugs/connectors in cars as well as spark plug wires the stuff is golden. I have a scoshe 100a right now with a clear cover on it and no problems, but it stays very dry behind the battery anyway.

I've seen it in cans you put on with a roller too but have no idea how it looks. You might use less if you seal the wood with something first, like paint or resin/whatever. I have done that and used stone guard in a spray can but it is smoother than bedliner. I know a guy that used bedliner cans on a trailblazer, he only did the bottom 4" or so and used about 30 cans IIRC of the good 3M stuff. You can spray the stone guard with a cheezy air gun that a qt can screws onto. It will texture like bedliner though maybe not as thick but should work fine on mdf. You can paint it or maybe tint it, it is very dull if bare and made to paint. Can thin it to texture you want, and that gun lays it on in a hurry don't run it. Need a compressor for that.

If you go low-buck, there are other issues to consider. You will get more sound (per watt) out of an efficient driver using lower wattage, you can get more sound with 2, 3, 4 drivers also. Ported will be more efficient....so it can also depend your install/what kind of room you have. Class D takes a little less power too so you can have less electrical. Maybe you could figure what size amp you can run, then size the best sub(s)/enclosure to it to get the most? That is how I would look at it but I don't know how low your budget is. I've run pyramids that pounded on 150rms and been very happy with them, but I just listen to music. You could hear them a mile down the road actually, but the install/car was perfect too. Was 4 10s IB. You can get a 150rms brand name amp for say $30-40 used if you shop hard, cheap subs like that are <$20ea but that particular one is not made now so not sure. But in most of my cars I could not make that setup work as well as that car design. With a single sub you will need much more power and obviously a better sub, or if you want huge volume. For my .02 I would get a good HU and front stage first and use the cheapest subs I could find if I were starting from scratch with no budget...but I guess if all you want is big subs then you spend what you can on subs alone. You should know that big power subs need big power to work right, so try not to plan on good subs and a large enough amp later on. I just sold a few 1Kw class d amps for about 100 each, unless you want new then these guys can tell you what to get. Also can you make a good box?

Also depends on the ohm load you are running amp into, and that changes with heat. To test IIRC you run amp into resistance load you will use, run test signal and scope to see clipping, then measure voltage. Then you measure ohm load when done while resistance is still hot to calculate power produced by amp into that exact load. You can use a speaker also if you have one you can beat that hard. If you have a device to show you clipping you could do it in car. I'm not sure how the clipping indicators work on amps that have them. If you know what power an amp puts out you can get close looking at voltage, but there are variables to the install that make it hard to do; the amp will never be exactly as it was on a test bench as far as actual load on it and input voltage. When you see the clipping you know for sure....it is like guessing how fast a car goes via HP, gearing, and aerodynamics...or running it on a track with a GPS.

M5 knows; I have the same issue and my plans are to maximize midbass from my comps first and see where I am at. This includes deadening and sealing of the doors and maybe a baffle/enclosure of some kind for them. Starting to warm up here so I can get on that. I want to do 8s but in this car placing mid/tweeters elsewhere would be a large challenge and near impossible to keep stealth so trying this first. I like to run rears to help midbass, in this car they are very low and just behind the seat and even same distance to me as fronts...ideal as they are not very directional. But most do not like rear 'fill' I guess.

I agree, set up sub sealed and go big on the midbass. Run 8" if you can even 6x9 can do well IMO if you have to. You need reasonable power on the mid if your sub power is big. Then you should still be able to set the sub LP somewhat low to keep directionality minimized. You may need an enclosure/baffle/etc on the mids to get the most out of it.

Usually you get a voltage drop through an isolator, that is why you don't use on amps if you don't have to. You can also run like a boat switch to cut power to second battery if you want to not kill the car if it is not running. My kicker will shut off and my car will still start. I would recommend you fuse every wire you add at the positive post of any battery you add wire to or install.

A tech told me if you don't see a picture of a good trace on the screen and they specifically say it works properly, then it does not and fixing one and getting parts is not easy....non-working ones are not even worth shipping in his opinion unless you are skilled enough to repair them yourself.

Can also try playing it at lower volume it stays on at, and see if it gets hot after 20-30min (too much current).....or does it do it at any volume? They can shut down before they get the sink warm if the protection circuit senses voltage out of range, it takes a little bit of time to warm the sink and with a short/etc it can cook the chips before the sink gets hot. There are other things that can happen that might not heat it up anyway.

Lol, I guess there might be someone out there that has never read ratings for amps....and does not know how a transformer works, or that amps have one, etc. Some amps will run about the same output 12 to 14, but is not common....they all want more output and by doing that you would limit 14v output to the same level as 12v more or less.

I sold a 900wrms kenwood class D a while back for ~100, it was nice and they are on there all the time. I only had a 400wrms sub handy to test and had no problem maxing that out but did not want to trash sub. Sounded nice. There are other good amps in that range if you have that budget, and many amps that are not built as well. Just a suggestion as they seem to be overlooked. Around 1kw rms with a brand name for ~100 is not a bad deal I didn't think, it sat here and ended up I had no use for it. IMO a larger amp will work better long as you don't over drive your sub or clip it....if you do that then get a smaller amp and save yourself the destruction. I have a kicker in my car, it runs my 4 12s great but changing setup soon.

Here are the ratings for an Alpine MRV-1002. This amp has a regulated power supply, I have tested the rail voltage and it does vary the driver duty cycle in the PS accordingly to keep it stable. Note the 50% change in ratings. In real life that is not 50% louder of course, but still a significant difference. Why else do you think all amps are rated at 14.4v now, and most cars can't even do that. Yes it is marketing, most people will never see 14.4v ratings get to their speakers. Power Output at 12V (20Hz ~ 20kHz): 2 x 100W @ 4 ohm (0.08% THD) 2 x 200W @ 2 ohm (0.3% THD) 1 x 400W @ 4 ohm bridged (0.3% THD) Power Output at 14.4V (20Hz ~ 20kHz): 2 x 150W @ 4 ohm (0.08% THD) 2 x 300W @ 2 ohm (0.3% THD) 1 x 600W @ 4 ohm bridged (0.3% THD) http://ampguts.realmofexcursion.com/Alpine_MRV-1002/

What part don't you agree with?

Come on guys, a better/fresher/bigger/second battery holds more power. So when the amp draws the weak alternator down to the 12v of the battery....a weak battery will drop lower maybe 10v if you overrun it that bad (and make your headlights dim badly). Remember that the battery still has to run the rest of the car. Strong battery setup will stay at 12 or closer to 12. Big alternator will run it at ~14 so that is why everyone says go alternator because you get more music wattage at 14 than 12v. You test at your amp to find out what you got. If your wiring is not large enough you will have lower voltage at amp than at battery, larger difference the smaller/longer your wire is (at max draw). That is why you run large wire to trunk; small wire will lower voltage x amount per foot...meaning short run is ok if it large enough to not get hot but long run needs to be larger yet to keep voltage up when you add up all the distance. Note that if you have a monster alternator that can supply the amps at 14v all the time, you don't have as big a need for multiple batteries for when it overdraws the alternator down to the 12v battery because it wont. OMHO I don't worry about changing the stock wire to a stock alternator because you did not change the output of that alternator...and factory should have right size wire on it. This may not always be true and it may help a little bit, but often I don't see a difference. I would not recommend taking out any stock wiring I try to add to it if possible, and that is just more 'free' wire but that is me. I would check the alt wire and any connections if you leave it, make sure they are in good condition. You can test voltage at alt and battery to find out loss under max load. So it really depends on if you want 14v or 12v, how much you want to spend, etc. You must have the big wire to your amps to get what power you have, and a good battery is good because you still need a buffer for any alternator or it is harder on the alternator. They can't react really fast but the battery power is always there to cover for it. Of course if you run it with the car off the battery(s) are your only source and more is better. More capacity and more of them. I don't like a real deep charge battery because they are not made for a large fast draw. It depends on your draw and number of batteries if you want to use them, or use a starter deep charge that can do more draw at once. Unless you play if for a long time on battery alone I would not worry about them, if you did that a deep charge can hold more total power. That should all be right, hope that helps you understand how it works better so you can set it up best for your use. You can find calculators for wire loss and stuff on the net.

Not sure about power but I have fixed two of them and both had a power issue not outputs blown. One the ground must have been bad and it grounded to the case and blew a ground inside, or someone hosed the wiring up I don't know. The other blew a small component that powers up some stuff, not sure why but it is pretty beat up amp even had dirt in it. Could have been an issue with 12v power to it or it just died on its own or from heat. I didn't test them to full power, but they seemed to sound quite clear and went pretty loud for 10A I ran into it compared to other amps at 10a draw....so likely it is efficient. Nicer one I sold used for 100 just like that and saw others sell, so they can't be that bad and you know you can get that out of it. Think that one was 900rms @ 2 ohm. They are screwed together pretty good for vibration resistance. I don't have any particular love for kenwood, they seem ok I guess but have not run one in my car for many years and don't need that big of an amp right now. I mean, they seem like a good amp but I have not run one.

I don't think any of them should burn, except possibly in a very cramped install....still should be hot but not burn you. They pack so much stuff in there they all run hot, in particular the high power ones they now tell you to wire to battery alone. But sounds like yours is hotter than it should be. If you run it on bench in open air no way it should be that hot. The outputs it depends, some do not really turn it off all the way not sure on yours. Often it is a power supply that makes heat too, many you can just pop the bottom cover and look at the board to see the 12v go to PS, and also see the speaker leads go to the output (usually is a sink for each). If you can tell where the heat is originating from that is. Of course don't break a seal for warranty if it is new.

I never checked my older alpine, but I know if I play it for a while it will warm up the CD nicely. I've never used the internal amp. On the other hand heat is not good, I'd cool it if possible or make more air flow/etc.

I have an alpine that seems to work well. I'd say the greatest advantage is being able to handle it while on the road; this for a dash mount type of EQ. I find most CDs/songs are mixed differently and require adjustments to make me happy. Can't do that with a HU or trunk EQ. I can change the crossover and sub gain, and with this one parametric on the bass plus a few higher band ones I don't use that much. On the other hand an EQ to balance out your system in detail will be much too complex to have under a dash/etc., but I don't need that just enough to balance the music sources. I also like to control the bass to mid crossover points, but the parametric helps more.