RMS capabilities

[Slick]

I know alot of us on here have installed sub systems in our Yarii. My question is, does anyone know how much power we can pull from our car before something starts to go? Say, could it stand 2 1100 rms subs? on a 3,500 watt amp? Who has pushed there vehicle to the max? Any help will be appreciated

[The Architect]

I had a zx1500.1 rated for 1799rms @2ohms and I pushed it rather hard....constantly.

come winter time my yellowtop had problems starting...then it wouldnt start. the yellowtop had effectively died.

Im now down to 1200rms for the sub amp and 120rms for the front components amp.

I maintain my yellowtop with a ctek charger if it ever falls below 12.8v for a cold dmm read and I turn off my radio etc a few minutes before i get home to give the alt. a chance and I've had no problems yet.

My current voltage readings are 13.8-14.23

[IllusionX]

Another local member had an Orion 4x100wRMS amp for his speakers, and then a 200wRMS Orion amp for the sub...

the battery alone with the OEM alternator was not enough for it. Not to mention the 4x100w is huge.. took 3/4 of the hatch space. He ran gauge 0 wire for the 2 amps...

i don't know how you guys push thousands watts RMS :(

[talnlnky]

Although you can install tons of amps in a car... realistically, due to the size & voltage of our alternators.... and the stock battery.... you are pretty much limited to about 1000-1300 watts. Anything higher than that and your car won't be able to sustain it for very long.... course... most music doesn't supply constant bass.. and that's where most of the power is eaten up.

to answer IllusionsX's question..... his buddy was running a Class A/B amp which is about 50% efficient... so... his 400 watt speaker amp really was pulling more like 800watts. The 200watt amp may have been Class A/B (50% efficiency) or maybe even a Class D (70-80% efficient).

Now days most people run subs off Class D amps because it saves a lot of power, and means you can get more rms before your electrical system becomes the bottleneck.

Upgrade the Big 3, and that'll help most people squeeze out a few hundred more watts

[sqcomp]

Architect has exemplified what is happening with the charging system rather effectively.

The physics are sound. The alternator can only push SO much out. After it keeps maxing, the amplifiers look for more potential...from the battery.

Now, if you're not leaning on a big Ampere drawing system constantly, supplying power for the short duration shouldn't be a problem. This is given the proper safeguards of course...The big three (which I've proven can be done properly and neatly for under $13), an aftermarket battery, and if you so choose to put another load on the alternator, a cap.

The stock Yaris alternator is what, 80 Amperes? It will provide your entire vehicle 80 Amps...no more. After your amplifiers go beyond what the stock setup can produce, the battery takes it from there. This is why Architect charges his battery (wisely I might add). After my little tour here in Iraq, I'll have four amplifiers in my trunk, one that will be loaded to 1 Ohm and in a perfect world, able to put out at least 1500 Watts. Will I EVER take it to that extreme? Hell no. I'm a little girl when it comes to sound quality...I whine when the car doesn't sound realistic (i.e.-too bass heavy).

The truth is, that we DON'T push thousands of Watts consistently. We do, however, have the potential to push that Wattage given the right ingredients. If you pushed that much Wattage consistently, your stock alternator would die a horrible death rather quickly. I remember such an experience myself. It happened to me using three amplifiers, two of the "older" Kicker ZR360's and one Kicker ZR600. Each 360 was pushing a D series solo 15". I was stranded approximately 50 miles from my home one day after hiking...guess what happened. Those amplifiers ATE my alternator ALIVE over the course of several months.

Take this for what it is, be work your system smarter NOT harder!

[sqcomp]

Hey Taln...nice MPG! That is what I'm getting after my big 3. Where's you get that pretty counter anyway?

[Slick]

Well, I plan to run 2 of these at 4 ohm http://www.onlinecarstereo.com/CarAu...roductID=15441
However, I am questioning the power capabilities of my current amp http://www.sonicelectronix.com/item_...ar+MXA282.html

Its true output at 4 ohms is roughly 750 ish, all things taken into consideration.

The amp is 1000 rms at 4 ohms each channel. However, if I'm not mistaken, you cannot wire a single DVC 4 ohm sub to 4 ohm, either 2 or 8. Correct me if i'm wrong. The problem i'm having is that the amp is rated at 1600 rms at 2 ohm. The subs are only rated 900. Even if the amp is capable of only producing even 1000 rms at 2 ohm per channel, wont that severely injure my subs?

Now, I know you can wire 2 4 ohm DVC subs to 4 ohm together in parallel but in order for the amp to see 4 ohm I would have to bridge the + of the left output on the amp with the - or the right output. And again, please correct me if I'm wrong. I only half-ass know what I'm talking about :) If i wire the subs up like that then that means it will be trying to push the full 4000 watts. Obviously not going to be that much but you can sort of see where I'm going with this.

I have been trying to figure this out for about a week now, asking ppl different stuff tying to get a fix on what to do.

Can anyone please give me a REALITY CHECK and explain this stuff to a freakin noob, I will be forever grateful. Thank you in advance.

[IllusionX]

Originally Posted by talnlnky

Although you can install tons of amps in a car... realistically, due to the size & voltage of our alternators.... and the stock battery.... you are pretty much limited to about 1000-1300 watts. Anything higher than that and your car won't be able to sustain it for very long.... course... most music doesn't supply constant bass.. and that's where most of the power is eaten up.

to answer IllusionsX's question..... his buddy was running a Class A/B amp which is about 50% efficient... so... his 400 watt speaker amp really was pulling more like 800watts. The 200watt amp may have been Class A/B (50% efficiency) or maybe even a Class D (70-80% efficient).

Now days most people run subs off Class D amps because it saves a lot of power, and means you can get more rms before your electrical system becomes the bottleneck.

Upgrade the Big 3, and that'll help most people squeeze out a few hundred more watts

you are right about the AB class amps... but.. why would anyone sacrifice sound quality for more power? :) I would not go for a class D at any time soon lol

[talnlnky]

Originally Posted by IllusionX

you are right about the AB class amps... but.. why would anyone sacrifice sound quality for more power? :) I would not go for a class D at any time soon lol

because they are only used for 250hz and down.... where its really hard to tell the difference between D & A/B.... the lower you go... the harder it is to hear. I personally never run sub amps crossed any higher than 60hz (when I had a decent component setup).

I doubt you could honestly tell the difference consistently between A/B & D in a blindfolded test.

I personally am all about efficient setups... I currently only own 2 A/B amps... but would do a D for my sub stage anyday.... if I planned on having a substage long term (my dream setup won't even use subs.... won't need them, my midbasses play a bigger range and better than a sub could).

[sqcomp]

The only reason I'm using four amplifiers is because I'm going to be running a three way set plus two 15"s on tha one big D class. Gotta have all my component speaker pairs on a four channel of their own...it's called headroom!

400 potential watts to the tweeters is going to be fun to control. I'm thinking that the Bit One is good at attenuation though! :)

[talnlnky]

Originally Posted by sqcomp

The only reason I'm using four amplifiers is because I'm going to be running a three way set plus two 15"s on tha one big D class. Gotta have all my component speaker pairs on a four channel of their own...it's called headroom!

400 potential watts to the tweeters is going to be fun to control. I'm thinking that the Bit One is good at attenuation though! :)

yeah... and due to impedence issues those tweets will never see more than 20 watts no matter how high you turn up the volume.... I love headroom... tho I'm going to say you're going over the top since its on a tweet. Love to hear it when its done.

[sqcomp]

I'm still trying to nail down which source I'm going to use. I'd love to be able to comfortable use at least an old 7909...but with them dissapearing and maintenance costs going up...I'll force myself to use a new source.

As for the tweeter impedance (rising over 4 Ohms as the frequency increases), it's going to be interesting to see how those Exile Xi 4 channels, the bit one, and the source itself (with it's Voltage output)...and the car acoustices with all it's variables are going to affect the performance.

I WISH I could use a smaller amplifier on those tweeters too...Exile just doesn't make an amplifier at that level that puts out less power. Although, that's what a gain adjustment and volume pot is for...I suppose I could simply use two channels off the four but...

[IllusionX]

Originally Posted by talnlnky

because they are only used for 250hz and down.... where its really hard to tell the difference between D & A/B.... the lower you go... the harder it is to hear. I personally never run sub amps crossed any higher than 60hz (when I had a decent component setup).

I doubt you could honestly tell the difference consistently between A/B & D in a blindfolded test.

I personally am all about efficient setups... I currently only own 2 A/B amps... but would do a D for my sub stage anyday.... if I planned on having a substage long term (my dream setup won't even use subs.... won't need them, my midbasses play a bigger range and better than a sub could).

you are right for the low frequency...but do you SERIOUSLY need 2500wRMS for subs ???

i personally only have a 4 channel AB class 50wRMS for my fronts and two 8" subs on the rear deck.

[talnlnky]

Originally Posted by IllusionX

you are right for the low frequency...but do you SERIOUSLY need 2500wRMS for subs ???

i personally only have a 4 channel AB class 50wRMS for my fronts and two 8" subs on the rear deck.

I don't... but every D-bag 16-22yr old male on the streets seems to. I'm a huge proponent for high efficiency setups. I did the SPL comp setups when I was 18-22... I bought custom made alts, $160 bats, and 00awg cable.... Been there done that... its fun, and somewhat challenging, but for a daily ride its not much fun.

I have a very similar setup to yours currently... I run the dual 8's in the 1.2cuft ported @ 28hz box you see in my sig powered by an A/B amp bridged to get around 150rms. Then I run the front stock speakers (no rears) off the stock deck.

My planned system, when I get time, and access to a shop...
custom built 3 way components using an 8" midbass 4.5" mid and 1" tweet. The 8's would get 150rms each, the midrange and tweet would get 80rms per side. No subs.... so a grand total of 450watts of A/B power.

Honestly... most people will think there is a 10" sub and a few hundred watts hooked up.... I did this install in my mazda a few years back it it was amazing. Sounds like there is a sub hidden in the dash instead of in the back.

[RedRide]

Fist off speakers do not actually "pull" power/watts.
They simply utilize what ever the amp is capable to deliver.
It you attempt to drive an amp beyond its capabilities, it will simply begin "clipping" the wave form or go into some form of oscilation. This happens all the time (even with the stock sys) when you turn the volume up louder than the amp is able to reproduce cleanely. This usually does no harm to the amp.

The obvious solution is to match speakers and amp to prevent this. IMO there is no substitue for amp wattage and efficient speakers.

For every increase in 3 decibles, about double the wattage is needed to reproduce it cleanly.

Rember the deal where you take a penny and double it every day? By the end of the month you will be a very rich man.
The same priciple hold true with amp wattage. So, to stat with very efficient speakers to begin with, you are ahead of the game.

To add to this, very high and low frequencys need even more wattage.

Bottom line, I would seriously consider installing a seperate amp for the sub with the proper "crossover"

[talnlnky]

Originally Posted by RedRide

For every increase in 3 decibles, about double the wattage is needed to reproduce it cleanly.

Rember the deal where you take a penny and double it every day? By the end of the month you will be a very rich man.
The same priciple hold true with amp wattage. So, to stat with very efficient speakers to begin with, you are ahead of the game.

To add to this, very high and low frequencys need even more wattage.

Bottom line, I would seriously consider installing a seperate amp for the sub with the proper "crossover"

Good post, but the doubling of power = +3dB is very misleading.... 99.9% of speakers produced waste an ever growing percent of power as you give them more power.

Its called power compression, and happens due to two reasons...heat & movement, but basically, if you take a 100rms speaker and put 50rms into it, it's most likely already feeling the effects to a good extent, and if you put 100rms its really feeling it... and if you put 200rms into it it will barely be louder than 100rms.... course its not rms dependent but actually movement dependent, so putting the speaker in a ported box, vs a sealed box makes a huge difference.


so... your point of diminishing returns is even greater than what you posted, but finding a high efficiency speaker on the other hand won't put you that much further ahead of the game if it doesn't have a flat BL curve (keeps cone movement linear). I've got PDF's at home, but no net there... so I can't really post them

[sqcomp]

...Hence the idea to work smarter, not harder.

Hey RR, do you want to continue to tell how and what DOES kill speakers?

Also efficiency is only one of the variables that play into a good system. Even then it depends on the type of speaker, the environment it's in, and the signal it's recieving.

Simply basing the choice of a speaker by the sensitivity will not yield good results. Taln starts to illude to this as well. I can buy a Goldwood speaker that has a "99 dB" sensitivity but...it may not fit into my formula due to many other variables. Most won't figure this out until it's too late. If speakers were judged on sensitivity alone, we'd all be using HLCD's in our rides (of which I am a fan).

The signal amplifier itself is what will determine the life of your speakers. The amplifier's goal is to reproduce signal. Preferrable a high fidelity signal. This is all based on how and how well the amplifier itself is made. We should really stay away from starting a whole other topic here...it will suffice to say that sensitivity of a speaker is by far NOT the only or the most important factor in good sound from said speaker.

We could SO get into a big talk of AC, magnetism, transducer contruction (and purpose), crossovers, plus a heck of a lot more here...

[RedRide]

Well, of course the efficientcy of a given speaker depends on a few factors. This is a given.

For examople:
All things being equal, a "tuned port" speaker sys will be more efficient than a sealed "acustic suspension" sys.

Agreed, efficency should not be the only criteria in chosing a speaker. After all, they have to sound, good etc also.
I only brought this up in the contex of making the most of a low wattage amp.

What will kill a speaker? Feeding it more watts than it can handel .
Also, driving it beyond its accustic (volume) capabilities can some times dislodge the "voice" coil.