# what is the deal with 14.4volts?



## jockhater2 (May 9, 2011)

What vehicles even run @ 14.4volts? because it sure is making it hard for me to pick an amp when they all show their RMS ratings @ 14.4volts instead of 12.5

My moms 528i bmw doesnt run @ 14.4
My jetta vw doesnt
My 320i bmw doesnt
My brothers 2002 bmw doesnt
my brothers volvo 240gl doesnt
I think maybe my moms suburban does. But I never checked it.

But I read my manual for my amp clamp and its from bosch. And it says if your cars electrical system goes over 14.2 volts. you have a problem.

Is it just european vehicles that arent 14.4 compliant?


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Check at the battery... usually you'll get 14'ish volts with the car running at the battery.. It's next to impossible to charge a DC battery without being over voltage, there just isn't any potential to charge... 

Problem IS, by the time you get to your amps, you've usually dropped to ~12v 

Bout the only way to combat this is to up your cable size, trying to reduce voltage drop over distance via cable resistance..

There was a company, who is still in business (Jakobs) that used to make the "Accuvolt" which was basically a stepping transformer that kept your voltage at 14-15v constant like an AC line conditioner...


----------



## sqshoestring (Jun 19, 2007)

My car runs over 14.4 all the time....in the winter. Cold makes it go higher, and it will go higher right after you start the car to charge more. But no 13.8 or so is more a normal voltage in normal temps. It was an agreement with amp manufacturers that wanted the highest possible voltage to rate amps at, so they would rate the highest CEA. Old school amps rate 12 or 12.5, MTX was still doing it not long ago. Its near a 1/3 difference in power like 35 to 50 or 350 to 500.


----------



## jockhater2 (May 9, 2011)

I'm talking about 0 loads. No lights, heat, music or anything.

For instance. All of the cars I mentioned excluding the suburban because I have never looked. All of their alternators are good for 14v. so my question is. Is that practical. What cars on the road have 14.4 charging systems?


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

sqshoestring said:


> My car runs over 14.4 all the time....in the winter. Cold makes it go higher, and it will go higher right after you start the car to charge more. But no 13.8 or so is more a normal voltage in normal temps. It was an agreement with amp manufacturers that wanted the highest possible voltage to rate amps at, so they would rate the highest CEA. Old school amps rate 12 or 12.5, MTX was still doing it not long ago. Its near a 1/3 difference in power like 35 to 50 or 350 to 500.


It also puts out more amperage in the winter and when you first start it cold... 

which is why good alts are "hot" rated, because the rating changes with temp.. :laugh:

Jus to add to this..


----------



## ChrisB (Jul 3, 2008)

My car idles at 14.5 when it is below 70 degrees outside and measures 14.4x at the amplifiers. It is so bad that it causes the over voltage protection to kick in on my Stetsom 1k5H. Care to guess what amplifier is about to be removed from the vehicle?


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Man, wish my car would do a solid 14v at the amps.. then again, I haven't tested since the new alt.. so, don't listen to part of that..:laugh:

(generally, you don't get 14v in the trunk, jus sayin :laugh: )


----------



## sqshoestring (Jun 19, 2007)

ChrisB said:


> My car idles at 14.5 when it is below 70 degrees outside and measures 14.4x at the amplifiers. It is so bad that it causes the over voltage protection to kick in on my Stetsom 1k5H. Care to guess what amplifier is about to be removed from the vehicle?


One of the lucky few, or maybe not that can be hard on the battery and other electronics as well. In reality it does not gain you much dB anyway, unless you are into SPL 1v is not a big deal.


----------



## jockhater2 (May 9, 2011)

well since my car stays @ a solid 13.5-13.8volts I want to make sure I get an amplifier that makes 750 watts RMS @3 ohms per 12W7.

I could use some help. I am trying to find either 1 or 2 amplifiers to power my 2 JL 12W7s

I've narrowed it down to these amplifiers. They are all CEA 2006 compliant.
Any particular one a better choice for what I need

MB Quart Q1.1500D ( I found it for $280) (x2)

Bazooka MGA11000h ( $220 @ crutchfield with free shipping) (x2)

Or maybe a Alpine M2000? Would that be enough power. 750 watts per sub @ 3 ohms per subwoofer? and 13.5volts? (about the same as if I were to get 2 bazookas)

Clarion XH7110 ($265) (x2)

JBL GTO14001 (x2) 
or maybe JBL GTO24001(x1) it has more than enough power it shows. after the 13.5volts

I like the bazooka MGA1100h obviously because the price, and I know I will get the power I need at all times. by having 1 per subwoofer. But what are your thoughts?

I also like the *alpine *because I found it used. the 2010 model on ebay for about 300-400

FYI guys. I am not an audiophile. I have never noticed muddy, or boomy bass. It all sounds good to me.


----------



## jockhater2 (May 9, 2011)

someone also mentioned the MB quart DSC 2000D. would that be enough to handle both subs @ 500 RMS -750 each?


----------



## AccessDenied (Mar 8, 2011)

jockhater2 said:


> What vehicles even run @ 14.4volts? because it sure is making it hard for me to pick an amp when they all show their RMS ratings @ 14.4volts instead of 12.5
> 
> My moms 528i bmw doesnt run @ 14.4
> My jetta vw doesnt
> ...


what's the reason for you of running amps with 14.4volts?

if the point is to have a constant voltage in order to have a constant amps wattage output (that will give you same volumes on different frequencies (multiamp system) throughout a period of listening, tonal balance, stage and so on....) regardless of switching on car's equipment like xenon lights, conditioner, high accelerating and so on... the only way to do that is VOLTAGE STABILIZER like Sinfoni Powerblock or Carpower V-PRO/3000 or HELIX XXL powerstation or any other... but it's not come cheap!

I think it's reasonable to think about constant 14 volts only if you have a top hi-fi, hi-end car audio components otherwise it's a waste of money...

For example, Im thinking about it now, cuz I got pioneer dex-p90rs and deq-90 and Sinfoni Prestigio amps.


----------



## ChrisB (Jul 3, 2008)

sqshoestring said:


> One of the lucky few, or maybe not that can be hard on the battery and other electronics as well. In reality it does not gain you much dB anyway, unless you are into SPL 1v is not a big deal.


I think it is more of a curse and possibly why I had so many problems with certain brands of old school gear. I am not too happy about a certain manufacturer listing their over voltage protection at 16v when it is really set from 14.6 to 14.8 volts. Both their sales rep and their authorized repair center verified the lower voltage protect.


----------



## sqshoestring (Jun 19, 2007)

I know the old MRV alpines had a regulation in them that cut the power supply at above 14v or something, so it didn't puke all the opamps and such. I don't do SPL but am a little amazed people obsess over voltage. Convert it to dB and it does not add up unless you are on a meter. So buy a larger amp or larger sub, the stuff is cheap, I just don't get it. I can turn my car off and hardly tell the difference 14v to 12v, and its right on my HU. Yeah I can tell if its cranked and pulling the battery under 12 at rest, but only because I have one battery and 700rms of course it will. At normal volumes its really hard to tell. Pretty sure I don't even own a fully regulated amp that would not change output.(and compensate for power fluctuations)

It is what ever the voltage regulator is set to run, I see some cars the ECU does it now.


----------



## asota (Feb 7, 2011)

I'm not even sure what amps have fully regulated power supplies but if they do voltage imput means nothing till they reach high or low limits and they protect themselves. They will always feed the rails a constant voltage.


----------



## UNBROKEN (Sep 25, 2009)

My truck with a 220 amp alternator and a pair of 1050CCA AGM style batteries shows 15.1 volts at idle as well as driving at the gauge on the amps distribution block under the rear seat. Showed the same 15.1 with a stock 160 amp alternator also.


----------



## Bayboy (Dec 29, 2010)

Put a high output alt in my S10 and it makes no difference to the amps that I can "hear". Got rid of the lights dimming at idle, better operation of electric windows, and keeping the battery charged, but that's it. Other than that I could care less. Tuning is more of a concern now rather than how much power I can squeeze out of my amps.


----------



## jockhater2 (May 9, 2011)

i don't care about having 14.4 volts. i was just asking. who honestly has a vehicle that runs that high?


----------



## Bayboy (Dec 29, 2010)

That was the point of you asking... not that anyone cared. Just to see what others viewed or do run. Several run it, but obviously to little or no advantage. Personally I think CEA ratings are crap. Bring it down to real world (12v @ a certain THD) and more fakes will be exposed. All you have to do is not certify to be able to sport whatever ratings you want at a whatever voltage. Though there has been some great performers that didn't certify. Where's the truth? I think that was your point somewhat, correct?


----------



## HondAudio (Oct 19, 2006)

As it has been mentioned - several times - unless you have a voltage regulator, the voltage reading at your amplifier [or battery for that matter] is going to vary from car to car; as long as it's within the SAFE OPERATING RANGE for the amplifier, your amps will have no problem running and putting out close to their rated voltage.

The 20% increase from 12 volts to 14.4 volts isn't going to give you 20% more "DEE-BEEZ", so stop worrying about it, and concern yourself with whether or not your amplifier can handle the impedance the sub(s) will present to it.


----------



## jockhater2 (May 9, 2011)

that was my question. you nailed it. WHERE IS THE TRUTH. every company has to embellish their amplifiers. it sucks.

so out of these amplifiers for my 2 jl 12w7s. which should i get?

MB quart dsc 2000.1
bazooka MGA 11000H
or apline MRP 2000.1

it seems that MB quart is the cleanest sounding one.


----------



## NIU_Huskies (Feb 24, 2011)

I agree that the 14.4v standard is optimistic. I doubt that many people are getting that voltage to their amp. I get about 14.1v to my amp. My previous car was around 13.8v.

The companies get to claim their output at 14.4v but most reputable brands will list the wattage the amp produces at 12.5v as well.


----------



## Mike_Dee (Mar 26, 2011)

I've owned a crap load of cars, and none of them have ever ran at 14.4V Best was 13.2V. Less at the B+

All marketing hype.


----------



## Bayboy (Dec 29, 2010)

jockhater2 said:


> that was my question. you nailed it. WHERE IS THE TRUTH. every company has to embellish their amplifiers. it sucks.
> 
> so out of these amplifiers for my 2 jl 12w7s. which should i get?
> 
> ...




That being the case it would make good sense to stick with amps that publish ratings at "real world" voltages or use amps that rate over what you require @ 14.4 volts. Honestly I would go for the one that sounds the cleanest to you if you have auditioned them all. MB Quart in your case.


----------



## performula (May 7, 2011)

Just buy an amp that runs RMS off 12.5?!?


----------



## tnbubba (Mar 1, 2008)

just a way to sell amps with unregulated power supplies
which amp would u buy 100W @14.4V
or [email protected] V
its the same amps!

I;m old skool I remember raising hell when they introduced amps rated at 13.8V

I can tell you by physiscs you will NEVER get your alternator output voltage at the amp unless you have superconductive wire( o resistance)

oh u guys running 15 V + alt to get 14.4 at the bat! kiss you computers sensors and other OEM **** goodbye long term! they were not designed to take that long term over voltage. most specs are 17V and the HO alts will spike way above that! Not good to do to daily driver.. comp car ok maybe!

you can figure realistic with a solid 14.v alt you will get 13.8 at amp 
a 100 amps in 15 ft thru 1ga will still drop 3-4%

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies


----------



## UNBROKEN (Sep 25, 2009)

Fluke DMM on my batteries with the truck running shows 15.1 volts. Digital gauge on distro block after a 15' run of 0/1 shows 15.1. If you need pics I can show you...but it's happening. 
My stone stock 06 Dodge is the same 15.1 at the batteries...combined total of over 300,000 miles on both trucks....I think if something was gonna fry it would have by now. 
FWIW...the original motor in my truck was showing 14.6ish at the distro block....I guess the higher voltage is a cummins alternator thing. 
At any rate...nothing has ever fried.


----------



## humandrummachine (May 17, 2010)

I would go with 2 amps, such as two JL 1000.1's or something similar. I would surely try going with 2 amps running final impedence of 2 ohms to each sub instead of one amp running 2000 watts at 1 ohm. Seems like a challenge for the amp and might end up under-powering the subs.


----------



## jockhater2 (May 9, 2011)

how much torque does your truck make? LOL 900hp is SICK. I am guessing 1500ftlbs of torque

I was thinking of 2 amps too. Just to insure longevity and less stress on the amps. thank you.


----------



## tnbubba (Mar 1, 2008)

diesels right.. different beast..
I build equipment for lots of oem auto suppliers.. I know what voltage air bag sensors r tested too.. and it's not much over 15V, and lots of other electronics like dash lights, O2 sensors, map sensors n such.. 
CarDON's biggest failure in rebuilt electronics.. voltage spikes! and most are caused by ****ty replacement, HO, or incorrect alternators being installed.
most stuff that goes on the diesels are rated at 24v btw!


----------



## jockhater2 (May 9, 2011)

see. that is what I was getting at. My bosch manual says for german cars that if the voltage is above 14.2. YOU HAVE A PROBLEM. Like you said. The computer and other components will go bad. 

I have tried any of the amplifiers.
I might go with the bazooka because of its price. And If I am going to get 1 amp per subwoofer. I know the bazooka can handle it.


----------



## humandrummachine (May 17, 2010)

jockhater2 said:


> how much torque does your truck make? LOL 900hp is SICK. I am guessing 1500ftlbs of torque
> 
> I was thinking of 2 amps too. Just to insure longevity and less stress on the amps. thank you.


yes, i think having 2 amps will produce better sq too, because the signal going to the subs will be cleaner if the amps are running at 2 ohms or higher. something like that


----------



## jockhater2 (May 9, 2011)

wow. 24volts for diesels. I am in love with diesel

you get AWESOME low end, and midrange power.
great gas milage
awesome torque.
and the engines are bullet proof practically.
and now so are their wiring. thats beast.


----------



## jockhater2 (May 9, 2011)

they will be @ 3 ohms due to the W7s single 3 ohm voice coil.

I am not picky about sound quality. My power acoustik cheap amps sound great to me. So I know I will be happy with a better brand of anything.


----------



## humandrummachine (May 17, 2010)

your going to need an amp that does 2000 at 1.5 ohms, or two amps that do 1000 each at 3 ohms. No doubt going to be pricey for the real deal there


----------



## jockhater2 (May 9, 2011)

the 12w7 is 500-750RMS. 1000 is pushing it for decibels. I want reliable daily driver


----------



## ChrisB (Jul 3, 2008)

You could probably get by with a 2000 watt 1 ohm stable amplifier. In theory, 1.5 ohms would put you right between the 1 and 2 ohm power rating. In real life, your power will be all over the place due to the reactive nature of a subwoofer's impedance while reproducing music.


----------



## Bayboy (Dec 29, 2010)

jockhater2 said:


> the 12w7 is 500-750RMS. 1000 is pushing it for decibels. I want reliable daily driver




If you want something for a daily driver, handles 1.5 ohms easily, and can push two of the 12W7....


Answer.... One of the most economical beasts of all time: JBL BP1200.1


----------



## subwoofery (Nov 9, 2008)

Did upgrade my alternator coz I have a second battery in the trunck. 
Got a nice and steady voltage now, around 14.3V : http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/102093-cable-size-s.html 

Kelvin


----------



## scotty89 (Apr 7, 2011)

jockhater2 said:


> i don't care about having 14.4 volts. i was just asking. who honestly has a vehicle that runs that high?


Its just a rating that most decent amp companies will use.

Pretty much all car audio is rated to work within a range of about 11.5volts to 14.4volts. Most honest brands will provide a rating at both 12v and 14.4v to show the range within which the amp would be expected to perform.

It's just that the amps will get the best power ratings from 14.4v.
Higher voltage requires less current for the same power, so if you hold the voltage constant at its highest possible, and increase the current to its highest possible you will get the maximum power figure.

This doesn't mean you have to run it at 14.4v 100% of the time. If your cars electrical system is healthy you're probably running over 14v's at idle with the car running anyway.

The amp's are rated at 14.4v because its the upper limit of the acceptable range. It's like rating a car's horsepower when you only run the car half way up to its rev limit - the figure won't best represent its optimum or maximum output. The car might have 200hp, but it can also put out anything below that as well.

When you're listening to music the power is transient - you wont be running at 100% of maximum power at every instant that the stereo is on. The ratings are just for comparisons sake.


----------



## asota (Feb 7, 2011)

A amp with fully regulated power supply witch most better amps are now days if it makes 100rms at 14.4 volts makes 100rms at 12 volts it makes 100rms at 15volts and so on between the limits of high and low protection. Even the old PPI Art amps that rated there power at 12 volts did not make anymore power at 14.4 volts because they had fully regulated power supplies.


----------



## HondAudio (Oct 19, 2006)

HondAudio said:


> As it has been mentioned - several times - unless you have a voltage regulator, the voltage reading at your amplifier [or battery for that matter] is going to vary from car to car; as long as it's within the SAFE OPERATING RANGE for the amplifier, your amps will have no problem running and putting out close to their rated *wattage*.
> 
> The 20% increase from 12 volts to 14.4 volts isn't going to give you 20% more "DEE-BEEZ", so stop worrying about it, and concern yourself with whether or not your amplifier can handle the impedance the sub(s) will present to it.


Whoops - I corrected my own post.

Buy whatever amp puts the appropriate amount of power into the impedance your subwoofer system presents to it. If you have a single subwoofer rated at 4 ohms nominal impedance, and it's rated for a maximum of 200 watts RMS, then find an amp that will put 200 watts RMS into a 4-ohm mono load. You can't get much simpler than that.

In as far as how "clean" an amp sounds - even someone with the best hearing in the world would be hard-pressed to hear a difference between amps when listening to a subwoofer channel only.


----------



## HondAudio (Oct 19, 2006)

humandrummachine said:


> yes, i think having 2 amps will produce better sq too, because *the signal going to the subs will be cleaner if the amps are running at 2 ohms or higher*. something like that


No. This makes no sense at all.


----------



## humandrummachine (May 17, 2010)

not the signal from the hu, something like the power being clean


----------



## nineball (Jan 17, 2008)

jockhater2 said:


> that was my question. you nailed it. WHERE IS THE TRUTH. every company has to embellish their amplifiers. it sucks.
> 
> so out of these amplifiers for my 2 jl 12w7s. which should i get?
> 
> ...





jockhater2 said:


> I have tried any of the amplifiers.
> I might go with the bazooka because of its price. And If I am going to get 1 amp per subwoofer. I know the bazooka can handle it.



assuming your second entry above was a type-o how do you know that the mb amp sounds "the cleanest" without having auditioned any of them? if you are this concerned over amp ratings alone why just go on someone else's opinion for amp selection?


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

tnbubba said:


> just a way to sell amps with unregulated power supplies
> which amp would u buy 100W @14.4V
> or [email protected] V
> its the same amps!
> ...



*Something has been nagging at me ever since I read this post and replied in it and YOU finally touched upon what it was.... 

Regulated VS unregulated power supplies....

Very few amps these days run unregulated power supplies... 

This means that the power supplies in the majority of amps don't really care if you are running 12v or 15v... the regulation negates a lot of this... 

*


> *In an unregulated power supply, the engineers simply use the transformer ratio along with the primary voltage to determine the rail voltage but battery voltage fluctuations (and copper and core losses) cause the secondary rail voltage to fluctuate. In a stiffly regulated power supply, there is a circuit which continually monitors the rail voltage and varies the duty cycle to keep the rail voltage very close or exactly at the target voltage. At no point in time, under normal operating conditions, will the rail voltage fall below the target voltage. *


Regulated vs Unregulated Power Supplies


----------



## rc10mike (Mar 27, 2008)

Im usually running 14.5-14.9v to the amps when cold...14.0-14.4 when hot...

Never goes below 14v.


----------



## jockhater2 (May 9, 2011)

i never said one amp was cleaner sounding. i haven't tried any of them.
It's either the...
Hifonics Brutus BRZ 1700.1d
or the MB Quart Q1500.d


----------



## St. Dark (Mar 19, 2008)

Aaron'z 2.5RS/WRX said:


> Very few amps these days run unregulated power supplies...
> 
> This means that the power supplies in the majority of amps don't really care if you are running 12v or 15v... the regulation negates a lot of this...


There are plenty of unregulated amps, still. Like Ford - Chevy, AR15 - AK47, Ga - Ga Tech, whatever, lots of adherents on either side of the regulated - unregulated debate. In reality, if the amp is well designed and well built, as others have posted you won't notice a difference just because of that aspect of the power supply for anything other than a fraction of a dB in SPL competition.

Plus, if your (supply) input voltage is sagging, it's because current is dropping off. Less voltage in for the same wattage output means you gotta put more current in...except that there is only so much to go around and you're nearing the limits or else your voltage wouldn't be sagging. So, in a car, output wattage at different voltages on a regulated amp can still drop versus on a bench hooked up to a power supply where one can intentionally raise and lower the voltage with a dial but still have full current output. Don't let that be the deciding factor in your amp decision, is all.


----------



## sqshoestring (Jun 19, 2007)

The #1 thing to worry about with a sub amp is does it produce rated power. The second thing is how long will it do that and what warranty does it have. The cheaper amp you get the greater chance it will fail at one of those things, but not necessarily as new amps are quite good even cheaper ones (excluding the very cheapest). Look up tests/reviews/threads on your final choices and make your best call, unless you can find a direct comparison or test.

It is easier on the amp to run the higher load 4 ohms, but while it may have a miniscule more THD at 2 ohms no reasonable and common amp is going to have enough you can detect it in sub use if even any use. Its just not very hard to meet common specs published, its harder to make it last in this very competitive market where they cheapen it as much as possible for the lowest price. Differences in sound from an amp are very likely to be built in SS filters to conserve power, EQ built into the amp (RF was famous for this), how it clips which is outside of ratings (if it meets ratings) so that really can't count against the amp even though a factor if you push to the limit. I could clip my kicker sub amp because the subs were good for 150% of rated, even then the distortion was not that bad and it would not go louder with more input. I was impressed they had done it that way. I am confident it did rated or more judging by what it clamped at. It was a refurb so it had a problem, but I ran it for three years on an IB baffle with four 12s 1" from it with no problems. Middle of the road amp, just saying pretty good deal for the price as are many other amps today from good companies.


----------



## jockhater2 (May 9, 2011)

thanks for all of your help you guys.

I think the Hifonics BRZ is my best choice. It has great reviews for its price, it puts out rated power, and the 1700d is WAY more power than I need. So I won't be stressing the amp in any way and it will sound much better than my Power acoustik amps.


----------



## humandrummachine (May 17, 2010)

jockhater2 said:


> thanks for all of your help you guys.
> 
> I think the Hifonics BRZ is my best choice. It has great reviews for its price, it puts out rated power, and the 1700d is WAY more power than I need. So I won't be stressing the amp in any way and it will sound much better than my Power acoustik amps.


looks like a good choice


----------

