MTX amp

[68w/sbc406]

i am looking into putting a amp into my truck and i have one MTX 4402 and here are some specs i found on line
2 Channel Amplifier
Power 12.5V
Rated Power (stereo): 50 W RMS x 2 @ 4 ohms, 2 X 100 WRMS @ 2 Ohms
Briged Power 1 X 200 RMS 4 Ohm Mono
Power 14.4V
Rated Power (stereo): 85 W RMS x 2 @ 4 ohms, 2 X 140 WRMS@ 2 Ohms
Briged Power 1 X 280 RMS 4 Ohm Mono
Frequency Response: 10 Hz-30 KHz
Crossover hi/low 85Hz defeatable
Full range RCA output
Dimensions: 9.3"L x 9.75"W x 2.1"H
yet i can get a MTX 4244 amp for cheap (specs)
4 Channel Amplifier
Power 12.5V
Rated Power (stereo): 45 W RMS x 4 @ 4 ohms, 4 X 60 WRMS @ 2 Ohms
Briged Power 2 X 120 RMS 4 Ohm Mono
Power 14.4V
Rated Power (stereo): 55 W RMS x 4 @ 4 ohms, 4 X 100 WRMS @ 2 Ohms
Briged Power 2 X 200 RMS 4 Ohm Mono
Frequency Response: 10 Hz-30 KHz
Crossover hi/low 85Hz defeatable Rear
Hi pass 85 hz fixed front
Full range RCA output
Dimensions: 11.5"L x 9.75"W x 2.1"H
i dont know alot about amps and i need help understanding. the first amp is in my gfs car and the sub will cut out for a few minutes if it is a heavy bass. i dont want a under powered amp.
thanks for any info

[slammmin72]

if u dont want an under powered amp...then dont get get a MTX amp....there are only a few quality amps that i like:
1. JL audio
2. Alpine

just my 2 cents worth

[68w/sbc406]

well thats not what i wanted to hear which one can put out the most power out of the 2 to run a sub?

[slammmin72]

what kinda sub(s) are u gonna run?

cause i have/had a sub setup in my 84 suburan 3/4 ton with a big block and 4:11gears.....theres no beating that.lol. (no longer has the speakers in it because i now drive my 72 gmc)
i had 2 Polk Audios GNX104 subs in it (fry's special...25 bucks a piece) my friend and i bought them as a joke along with a cheap 50 buck amp. it was rated at 300 watts single output, but 500watts (divided by 2 subs=250 watts per sub) bridged, and the speakers RMS was about 250-260 (somewhere in there) the point is..we were always running them at their RMS(peak performance. i had them both mounted in seperate "house speaker" boxes (essentially ported boxes) and they were un-godly loud....they were so loud that u could feel ur hair vibrate along with the rest of ur body. it got to the point where u could only listen to it for a while until it began to hurt. they used to ask us to turn it down when we went through drive-thu's because not only could they hear it in there, but they could feel it in there aswell....in my opinion that was the best 50 bucks ive ever spent

i just need to know if u are putting in a sub for the the nice quality bass to enhance ur system, or if ur adding it just to slump super deep bass.

[68w/sbc406]

well it would be for a JL audio 12" sub

[slammmin72]

i forgot something....is the amp in ur g/fs car mounted to the box?...cause after an extended amount of time, the vibration from the sub(s) actually tears apart the tiny soder joints inside the amp, causeing the amp to stop working when the bass gets super deep because teh lower the bass..the more vibration and resonating it causes.

also, did u already build a box for ur truck...cause i just recently built one for under the seat, and it was kinda tricky....lots of diferent angles, and i had to raise my seat about an inch. i only have one sub in it cause the box could only be so big, and i didnt have the inside volume to support 2 subs. (just a heads up)

[slammmin72]

i recomend a 10".....crisper bass.
because the cab of the truck is rather small....u wouldnt have a problem with a w0

a 12" might be a little to over powering, plus ull have to get a bigger amp to power it (cause u cant run all 4 channels to one speaker) i recomend a mono type amp if u are only gonna run 1 sub.

How many watts is the 12"?

[68w/sbc406]

not sure again its in my gfs car. she was thinking about getting rid of it and i was going to steal her stereo. and the amp is mounted to the back of the seat, not the box

[Gary]

Here's a rule of thumb for car amplifiers, 10 watts of power = 1 amp of current draw (class D amps for subs can go more like 13 watts per 1 amp). Your GF's problem is most likely not the amp, it's the current draw, when current supplied gets too weak, the amp shuts down and then comes back on when the current stabilizes again. Your average factory alt only puts out around 80 amps of juice, give or take, and the car itself needs amps to run, I've read a typical car needs around 25-45 amps to run normally. If your alternator is putting out 80 amps under normal driving, when idling it probably ain't putting out more than 50 or 60 and if your car itself is using 25 or more, that leaves mighty few amps to give to car amplifiers. Does the headlights dim if you let the car idle and crank the stereo up? If so that's "not good" lights shouldn't dim too much even at idle.

Your amp would run a single 10 or maybe a pair of 10's with ease, in a nice sealed box you'd be in good shape. Mate the amp with the proper subs, there are 10 inch subs on the market (high excursion subs with like 10 pound magnets) that can suck up near 1000 watts of juice, then you have some nice sounding and quite pleasing 10 inch subs on the market that'll take like 100 watts of power, match the parts to the other parts to make a good match. Heck there are even 12 inch subs that WOULD mate with that amp fine, even in pairs, but you've (apparently) got an old Chevy truck, you ain't got room for a BIG OLD speaker box so a smaller sub is good because it needs smaller box! I'd rather put a nice medium wattage (200-300) watt 10 inch sub on that amp than 2 low watt (100-150) 10 inch subs, you could get by with a sealed box of around a half cubic foot of air in it.

My last system I had a 1500W sub amp w 80 amp fuse, and 675W 4 channel amp with 2x35 amp fuses (real out put was probably more like 900-1000 watts for the first amp and 640 watts for the second). This system used a huge amount of current. In my Geo Tracker I had a hand wound alternator (capable of around 160-200 amps of current delivery) and a "batcap 800" basically a battery mated with a capacitor that could deliver lots of current fast, then recharge that current quickly which helps equalize the draw of the system rather than having large spikes when bass hits. It worked fine in my Tracker, the lights barely dimmed when idling and the stereo cranked up. Before I installed it in my Tracker I had it in a Chevy full size van temporarily with factory alternator and no batcap at that time, and the motor would stall if I turned it up loud and it was idling, if the motor was revving I could make it start to die by cranking it up, the lights wouldn't just dim, they'd damn near go out completely.

Someone saying MTX sucks? Keep in mind, stereo equipment brand loyalty is ALMOST as bad as chevy/ford/dodge brand loyalty, it borders on cultism the way some folks "like" and "don't like" certain brands. MTX has been around forever and they wouldn't be here if they "sucked" they put out good stuff, they put out some cheap stuff, even today's cheap stuff will work good if you use it properly (don't throw 2 big 12 inch subs on that amp, but a single 10 or pair of light 10's will run FINE on it). I'm a big fan of hifonics amps, kenwood speakers, JVC decks, and audiobahn subs, and I've run into someone that swears every one of them sucks at one point or another. I've got a pair of 10 inch MTX subs sitting in an MTX Thunderforms box sitting in my living room right now, waiting on my amp and last pair of 6x8's to get here to be installed into my lightning. And oddly enough, the amp is a hifonics and the deck is JVC, however the speakers are MB Quart (another brand I happen to love). Personally I think JL Audio and Alpine, while EXCELLENT equipment, is just a wee bit overpriced, I'll keep half my money and buy hifonics/jvc/audiobahn/kenwood and put the half I saved to other projects and I guarantee you I'll still be happy with the stereo system. It's like watching guys on this board talk about their trucks, you have dudes with $5000 invested in just their airbag setups, and dudes running factory springs, and both are happy with their trucks

I'll probably put a similar system in my 72 except the full range speakers will be Audiobahn components (I have 2 pairs of them laying around out of my Tracker's old system) a single 10 or 12 audiobahn sub under the passenger's seat, and probably the same JVC deck I put in the Ford. Hopefully I'll be able to drown out the sound of the headers and flowmasters when I want to (not that you'd want to that often).

[68w/sbc406]

wow, thats long . her head lights do dim, so i probably need to run something heavier to her amp from the battery and put a capacitor and it would stop shutting off. thanks for the help