what is this 14.4v input ?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=21662
Printed Date: May 11, 2024 at 4:49 PM
Topic: what is this 14.4v input ?
Posted By: bassam_zaman
Subject: what is this 14.4v input ?
Date Posted: November 19, 2003 at 5:23 PM
Hi everone, i want to buy this mtx 801d amplifier, and in the specs it says 500w x1 @ 2 ohm(12.5 v input) and 800 w x1 @2ohm(14.4V input)/ No i understand this means when the supply voltage is at 14.4 there is 800 watts. I have a 2002 chevy trailblazer, and on the battery gauge in the instrument panel, it is always at 14.0V-14.5V when te car is on, does this mean that the amp will run at 800 watts or what??? I nee to know as i have to purchase within the nest few days, thanks, Bassam.
Replies:
Posted By: nedgeworth
Date Posted: November 19, 2003 at 5:35 PM
Yeap your thinking there is pretty right. As the current increases the power output does. But yes roughly your amp will put out 800watts MAX.
What subs are you hoping to run off this amp?
Posted By: forbidden
Date Posted: November 19, 2003 at 6:37 PM
If this is a big amp with fusing to boot, over time I would expect the battery voltage to drop. As your vehicle is fairly new, so is it's battery, you really have not begun to put a constant drain on it. A high power stereo system is certainly a constant drain. Much like when you wear out a tire, your traction goes to sh*t, a battery loses it's capacity to maintain a constant charge level. This is a generalization, not gospel for the true battery / alternator person. A good rule of thumb is to look at the 12volt rating and match your subs properly to the amp at that rating. This does not mean that your amp always and only puts out 500w rms, music is dynamic and goes up and down independant of the volume control. If you have more power available above 12volts, great, awesome, the amp will provide even more power. Before I chose this amp, post up what subs you have so someone can see if it is a good match.
-------------
Top Secret, I can tell you but then my wife will kill me.
Posted By: bassam_zaman
Date Posted: November 20, 2003 at 6:43 PM
Hi everone , ok i see that what im thinking is right.. Hey forbidden, if your battery starts becoming sh*tty the way you said, you can always change it right? Also, im running one audiobahn aw1200q sub, dvc(4ohm)(so 2 ohm, or 8 ohm operation), 700 watts rms, 1440 watts peak(ppl say these numbers are underrated, also the mtx numbers are underated), 12inch 120 oz. magnet. Its in a band pass box. I was thnking the MTX , cuz i could get a good deal , or the audiobahn a8000t amp , specs : 400 watts RMS x 1 at 4 ohms 800 watts RMS x 1 at 2 ohms MOSFET power supply requires 4-gauge power and ground leads — wiring and hardware not included with amplifier two 30-amp fuses 50-120 Hz low-pass crossover, 18 dB/octave variable bass boost (0-18 dB at 50 Hz) variable (20-50 Hz) subsonic filter preamp outputs cooling fan cobalt blue illumination phase shift (0-180 degrees) The power input of the audiobahn is 800 watts rms at 2 ohm, which is already way more than i need and, also this i way underrated. Anyone have any better suggestions?? Thanks, Bassam.
Posted By: bassam_zaman
Date Posted: November 20, 2003 at 6:44 PM
aorry i mean the power input at 12.5 volts gives you 800 watts at 2ohm
Posted By: forbidden
Date Posted: November 20, 2003 at 8:16 PM
A look at the amp on the site shows power output of 500w rms at 12.5v at 2ohm mono. Yes this amp will work OK for you, I would shop for something a little bigger myself if I had your sub but this is a good amp for you. Yes if the battery voltage stays higher the amp will make a little more power but the dynamic or peak ratings are just that, they are what the amp may produce for a brief (instant) burst of power, not a sustained output level. If you want a sustained, really loud output I would look for a bigger amp, otherwise go for it, if it's in your price range it's a good buy.
-------------
Top Secret, I can tell you but then my wife will kill me.
Posted By: bassam_zaman
Date Posted: November 20, 2003 at 10:20 PM
ok thanks forbidden, you said you own a shop with audiobahn amps or somthing, are the A8000T's a good choice just incase? Or will it be too powerfull for my sub? thanks alot for you help, btw where in canada are u located?
Posted By: si90lude
Date Posted: November 21, 2003 at 2:21 PM
Hey, it is always better to overpower than underpower speakers, as long as you don't get carried away 
Posted By: forbidden
Date Posted: November 21, 2003 at 9:02 PM
The audiobarn amp is not stable to a 2ohm mono load according to the book, I am a dealer of Audiobahn but do not expect to continue with the line. si90lude is bang on with his reply, a little too much power is never a bad thing, have a look at a slightly bigger amp, stretch that budget some, buy it right the first time. In Canada I can found lounging in the real honest to god home of most peoples poster girl from years gone by, Pamela Anderson, Courtenay, B.C. (for the sake of arguement she is from Comox, a whole 2minute drive away. My main store is located in Courtenay B.C. on Vancouver Island, our second store is located in Naniamo, BC also on the rock. Current weather conditions are below freezing, clear with wind off of the ocean, snow is expected, hopefully tons of it.
-------------
Top Secret, I can tell you but then my wife will kill me.
Posted By: freakystyley990
Date Posted: November 22, 2003 at 2:13 AM
The MTX 801D will put out 400 watts at 4 ohms and 800 watts at 2 ohms CONTINUOUS. That power rating is at 12.5 volts. However, your power output will be more than that becase as your battery power increases, so does the amp's power rating since that rating is measured at a voltage equivalent to the engine being off. Your battery will put out somewhere between 13.3 and 14.4 volts with the engine running. The PEAK power rating is going to be much higher than that regardless but an amp's ability should never be measured by its peak output anyways. In my opinion, that happens to be a very good amp. I have always been a fan of MTX mono amplifiers.
Posted By: forbidden
Date Posted: November 22, 2003 at 12:27 PM
No offence to Mr. Freaky up there, but it seems that one of us is getting our "specs" messed up. The MTX 801D amp is a very good amp, it is measured output at 12.5volts (yeah) but the continuous power rating as taken from the MTX website is 250w x1 at 4ohm and 500w x 1 at 2ohm. It's Dynamic rating (another fancy word for peak) is 400w x1 at 4ohm and 800w x1 at 2ohm. Yes the battery may well put out a higher voltage depending on a number of conditions like this: battery is new, alternator is good, supply to battery is good, drain from vehicle electronics is not excessive. When you add a high power stereo to a vehicle that had it's electical system designed for the vehicle and not the vehicle + a high power stereo system, one thing that suffers is current and voltage. This is a couple of reasons as to why so many people add high output alternators, caps, second batteries etc. They want to be able to maximize the capabilities of their system. Now like most American built or designed amplifiers they usually put out a little more than the spec sheet says, this is a good thing. If you have info that contradicts the MTX website info then that is great, post it up so we can all see it, the next time we need to recommend a product like MTX to someone we have a little more ammo to give that person.
-------------
Top Secret, I can tell you but then my wife will kill me.
Posted By: bassam_zaman
Date Posted: November 23, 2003 at 7:44 PM
hey freakey and forbidden, thanks for your replies, um freaky forbidden is correct with the specs he gave. But forbidden, its says that the amp will run 800x1 at 2 ohm at 14.4, i dont think that means peak power, i.e say the amp gain is at half way with the car off, it gives you 200 watts or watever, if the car is on, it will give you 400 rite? Plz explain this further , because the specs say the amp will do 500 watts x1 at 2 ohm when input is 12.5V, when input is 14.4 V, the amp will do 800watts x1 at 2 ohm.
Posted By: bigjerman
Date Posted: November 23, 2003 at 10:26 PM
Wanted to know if u dont get 14.4 from your electrcial system, is there anyway to up that without a new battery or higher power altenator. And uping the volatge in the rca line do anything like using a line driver? ------------- 1998 Volvo S70 T5 - It's Swedish isn't that weird?
Posted By: forbidden
Date Posted: November 24, 2003 at 12:57 PM
In order for the amplifier to maintain a continous power output a number of things need to happen, things like a constant supply of power at 14.4v, not dipping down to 10 (your headlightts are on, air conditioning on etc), a good solid ground, no excessive heat buildup on the amplifier - an amp is designed to get warm, but at some point in time all that heat buildup is from driving the amp really hard. Some amplifiers have a thermal switch in them that when activated, roll back or govern the amount of power going out to the speakers, I am not sure if this amp is one of them. Now let's hope that your vehicle delivers more than 12 volts, the amp will definitely give you more power. I did not dive right on into the MTX website, but from what I did see some of you may be reading what the manufacturer wants you to read. The DYNAMIC power rating is 800 watts at 2 ohm at 14.4volts, The RMS power rating is 500 watts at 2 ohm at 12.5 volts. "Dynamic" can be viewed as peak, some manufacturers even claim an even higher "Thermal" power rating in watts. Dynamic and Peak are (basically for the sake of arguement) one of the same, it is what the amplifier can produce for a brief instant in time, not what the amplifier was designed and engineered to do on a continual basis. Keep your gain control turned down, this is what it was designed to do, if you turn it up sure you get more power, however the tradeoff you get is increased noise floor and mainly the prime way to destroy your speaker by clipping the amplifier, the sub won't distort on it's own, it only reproduces what it is given, if you clip your amp causing it to distort, Mr. Subwoofer is going to do his job until one day you need a new sub. As I stated before this is a great amplifier, I would still look for a bigger one, the worst thing in the world you can do to a sub is underpower it, especially if you are the type that plays your tunz loud and long. I would add a capacitor to the system right away, as well a good line driver from Audio Control or a high voltage Eclipse cd player (CD 8443). See what people have to say before you make your decisions. ------------- Top Secret, I can tell you but then my wife will kill me.
|