sqguy

That should work good. Try to keep the 4ga to sub amp short as you can.

I used to say that, but now the line seems to be pretty blurry. People are using low Q drivers in HT IB all the time. I never have so I can't say, but can say it is harder to run a sub IB that has a higher Fs. In the old days that was a light weight coned driver with a higher Q. Just guessing but the door enclosure might add some support to a 10, and without <50Hz it might not be so bad. One could also do some aperiodic behind it but in the end I would like to try it if my car fit them so I could tell you. My 12s seem to work fine, they have Qts .48. I must max at about 100wrms each and they don't move much. Factory says half power for IB that is 150wrms each.

I was told RF bought the company but has yet to make the amps. They have some good components in them compared to other cheap Asian amps, but they are slapped together about average I saw one broken from vibration. I can get one cheap thought it might work for a spare. Have an alpine 500wrms I plan on using that I think will be enough but you never know. Just daily driver SQ with a little thunder now and then...and likely will run IB subs yet that don't take much, the 4 12s or maybe pair of 15s. My 420wrms I have now is not quite enough for these 12s but thinking of changing them out to something lighter or 15s as it is loud enough. Of course more power and SQ go together even if it is dialed down. I can get 3 of the 1kw class d, they can be strapped for 2kw at 2 ohm. But have no use for that much sub, what I have is really too much.....yeah that is just about right though.

Are these amps much good, for the price? Does anyone know if the 1Kw class D puts out actual and how about strapped? The guts don't look that bad inside, and I don't think they sold these at walmart.

I don't remember, I posted on one of the threads about 8s in doors. But there is a shallow 10" sub I was looking at that has a flat response much like the Peerless except lower. Mind you can't go very high with it like an 8, but it looked great on paper for a midbass. It's this one, a TB neo. Check out the chart up to say 200Hz+. http://www.partsexpress.com/pe/showdetl.cf...tnumber=264-862 Q is pretty low, price not bad, power handling not huge but how much do you need on midbass with the efficiency of a 10...88db. Well I have no idea how it would work but sure looks like a fun one to try for doors if you have the room. Really with a 10 a somewhat sealed door should have a box type effect long as you are not trying for 30Hz. Yeah they smooth those factory charts too but sure is much flatter than most others and it digs; looks like ~40Hz -3db.

Nobody has run these gems on subs??? Actually they have all Fairchild transistors in them, pretty good stuff. Not so good with vibration without some mods however.

It depends on distance. Smaller wire near capacity will have X resistance per foot, more foot of it = lower voltage. It is likely you don't want to use more than maybe 3' of 4ga and the rest should be larger or your 1500w amp will see less voltage at max power, and less output in watts. A little drop does little, but multiply by 15' distance trunk to battery and it adds up. That is why a fuse can be tiny wire, but it is so short a run (1/4"?) that it has a tiny voltage drop. If you don't care about running it at max power I'm thinking 4ga would work, but that usually not the case with sub amps they get run hard.

I've seen batteries short, it is not pretty. Torching a 16ga wire is one thing, discharging a 1,000+ cca battery or more with a large wire is another. That acid can make a real mess, and/or what melts or burns. You short a wire in your factory loom and you could be in for a lot of work to fix. I fixed a smashed car once and it quit running after a week, turned out a wire had fried in the loom near the damage. It shorted and took out the ECU. I had to pull all the wiring from the firewall to the front bumper and repair it plus buy a $200+ ECU. It was all wrapped up and looked fine but a wire in the bundle was bad and melted ones next to it, took a lot of hours to fix and good thing I had other vehicles to drive.

You need to fuse really soon when you come off any positive battery post to an amp or another battery; they say within 18" but sooner the better. You need to fuse again smaller if you downsize the wire after that. I was just thinking the front to rear cable is already fused at both ends so you could use that right to the sub amp since it will really need a lot of power. Maybe try a 100A on the rear battery and 200 on the front end? I'm not sure 4ga is going to be good for that sub amp. The high amp you could hook up anywhere with a maybe 60A fused 4ga or something. Just my .02 that seems simpler. Think I would try a 1/0 fused off the rear batt right into a 1/0 tee, split it to front and to sub amp. Just hook the high amp right to the battery with its own smaller fused wire. It would be just like running 1/0 right to the sub amp and adding in a second battery with a fuse on it closer to the amp.

The right way is to fuse any line that comes from a power source for the amount of power it can handle, so really you should fuse the smaller 4ga at less than the larger main line and that would fuse the amps too that are on the 4ga. But like I said lots of people don't, and chance of that short run of 4ga shorting or an amp shorting that way are low so its up to you. You are just fusing the wire so it does not catch on fire; smaller wire = smaller fuse. Then again, it takes a lot to smoke a 4ga wire possibly more than your main fuses but you need what, 300A for 2KW? Can you get a little more 1/0? If I were doing it I think I would put the main fuse on the rear battery, then I would hook everything to the fuse. Put the line to the front on it; run 1/0 right to the sub amp off it (if only 3' why not it would look cool too and you don't have to fuse it again), and then put a smaller fuse block with 4ga run to your high amp (or put that right on the battery if fused). Too bad they don't make a fused post mount, you could do it all right on the battery but I could not find one. The sub amp (& high amp if hooked there) hooked outside of both main fuses could see amperage from both however, but the rear battery on its own would have less power than the front plus alternator. But that way your sub amp would only see mostly one fuse in the supply not three. Make your main fuses equal roughly max draw of all amps depending on if the high amp is on the battery or on the front/rear line.

I've never heard of not grounding to the battery if it is right close by (say <3'), however you should ground everything to the car so all is grounded together and those should be a short distance from each component. The second battery has to be grounded to charge plus get current from the first battery, but I've seen the amp(s) grounded to it as well with no problems. They likely want a full ground for each amp so you don't try to pass more current through one connection, as grounds to the car may not be the best anyway. Unless I had a noise problem I'd rather ground to a nice clean negative battery post than a painted car body...twice, as it goes into the car then back out to the battery ground cable. But, that is just me and I've never had an issue with it. If you do, you need a very healthy ground on that second battery. I have soldered the lug to the car before. I would do option #2 unless your 4ga would be longer than a few foot on sub amps then #1.

I put a bunch of MP3 on my PC years ago, at a high setting and they still did not sound good so I gave up. I just use CDs or waves. Storage is getting so cheap though it would be nice to use something cheap and with larger capacity than a CD....since they kept DVD out of the market. Maybe a big flash drive/etc would work. I don't need 2K songs on it, but hundreds would be nice. I will not buy an ipod mostly because it is proprietary and because they are expensive for something that could be lost/stolen/damaged so easily. Also I would only use it in the car 99% of the time so what would I do with it? Carry it around? I can burn CD and care less if something happens to them in the car and have 100% quality.

If your amps have no fuses they should have one before amp, sized for that amp, but you know...some people don't bother to do that. If the amp were to puke and short, it would have to smoke your main 100A or whatever battery fuses. That could cause a lot of smoke in the amp before those fuses blew, if the amp by chance failed in that way. I don't know how big your amps are, but if you have a fuse every time + power comes off a battery then you have the minimum to be safe as far as your cables shorting and firing up the car or something...unless the smaller 4ga can't carry what your main fuses will pass. Right, you should have the same capacity (cable size) on negative side of batteries as positive. I would try to mount the second battery so the positive cable to amps is as short a distance as possible/reasonable and 4ga part is fairly short. If in trunk likely they will not be long anyway. It will carry the current of both batteries plus the alternator to your amps, but that shorter length has less resistance compared to the front of vehicle run. You get X resistance per foot for a wire size....so longer distances are much more important that they be large or they add up and reduce voltage.

They often cut out at 10v, but if a power problem you should see it on a meter when it happens. Also check your ground, check every connection. Right, it is easier to just swap something if you can't test. You can ohm the sub also if you have a meter. Is the amp on the box? If so it might have vibrated something loose, you can bump the amp a little and see what it does. If that affects it a repair may be easy since it likely has not smoked yet.

Try diyaudio.com in the car audio section.

IMHO or $.02, if you want some volume out of small amps on subs, you need efficient subs. They are usually low power, often cheap. You can't get today's HD high power subs moving with a little amp. Higher SPL of a sub the better, but you have to keep an eye on Fs and such so you don't have a tuning issue if you want some SQ. Often 10s work well on smaller amps but not required of course, just my experience from the old days. I used to run 60-100wrms/ch on 10s often and would be hitting xmax, in IB or large ported config. Sealed will often have less db also....ported gets you more and you need it all. For IB use twice the drivers, that helps. If you don't need to rattle the windows of the house next to you with bass it will work if set up well, can sound really nice. Run amp at 2ohms if it will to get the most out of it if you need, just cool it if it gets warm.

Bandpass is usually mids; you take out the bass (that goes to woofers) and treble (that goes to tweeters) at frequencies you need for driver/install/etc., and what is left goes to the mid. Or it could be a bandpass sub box that is tuned (ported) to produce only a band of frequency such as 30 to 90Hz. It could also be mid-woofers that would only be the higher woofer frequency (8"-6.5" woofer in a car door), or a dome mid that would be only the higher mid frequency as a dome does not go as low as a typical larger cone mid would. Either way, you will have a high and a low pass not just one or the other.

In a F-250? They are just in there with the rubber gasket right? Is so you might get a glass place to shoot urethane into it. that might help.Trucks like to shake the entire rear panel though.

They should just split these amps in half. Put a sealed power supply under the hood and run 100V+/- rail voltage back to the amp.

If you run two actives it doubles the slope right? Like a HU at 12 and the amp at 12=24?...if you can get them set to the same frequency. But will make them harder to integrate with steeper slope.

We did it with LP amps back in the day, but then you did not have high power HUs either and you could not turn it up that far because of distortion even with a good HU. But LP liked lots of input and some people are not so worried about quality, and you did not have to worry about line noise that way. I think pioneer HU with the worst line level ever were the ones I did that on. Way better to get a line driver like a LP PA2 back then. It depends on how the HU reacts to that high ohm load, and how clean it is. I would use a knockdown or the products they now have for that. I've had knockdowns that would let a lot of power through if you turned them up, but hey why not try it and see. Just don't blow the inputs of the amps.

I didn't think swapping an alternator could void a warranty. I'd get the numbers off it and see if another car has the same one with more beef.

Last night I was playing with a 10 I have, mass produced AB clone about $90 and 400wrms. In a ported box I see it really moving and its on about 300wrms as its bridged at 8ohm on a 150x2. Amp was not maxed and running on a big 12v (so even less wattage at 12-12.5v) battery in the house....but there is no subsonic control on that amp. 3" port at 35Hz just huffing away, why is that fun...but should do better on another amp with subsonic. Not my thing, but I can't even imagine 7kw on two 10s.

Lol hmmmm...they sure crack a smile when their hair starts moving...

I have a pa vx2200d here, it looks like a giant audiobahn inside. Then again the AB sure put out when I test them (on speakers/subs in house) considering what they are, but I've never run one in a car and I will not be using this vx. Those Icon look like really nice subs, I like.