Nope, JL took what would have been PPI's design. If they didn't do that then I doubht the JL amps would have done well.

Xtant was bought out by Mitek I believe....and I don't think they're much into innovation....

 

so i believe what MECP says is that if your system draws 110 percent of your alternator output it is time to upgrade it outherwise you are going to fry it[/b]

 

Based on your equation above I will have the following
2520W/14.4V = 175amps
The alternator I plan on getting is 200amps hot 240amps cold (so they rate it!)
Well then what the hell is the point of having such a huge cap? And is there a Farad to watt ratio as I mentioned in my first post?
I'm running 2 MTX 9500 12's in a Powered4Sound Double Shot box.
They will be receiving 1000watts per sub.
With the two smaller amps I will be running a set of components with each amp so I can keep my time correction.....At least that is the comcept.

I'm still torn on exactly which components to get....
I'm looking to get some that are stupid loud and sound good doing it....Leaning toward Diamond HEX S600's.
But those Dynaudio and Focal Utopias look so appealing!!!!!

 

So where is the best place to find a high output alternator and the battery to run all this in our xB? I was just wondering cause im gonna be running a little less then him but I am gonna need to upgrade also....Thanks, Tyler

 

Stiffening Caps
What are they? What do they do, really?

This definition will be in its simplest form. You will see audio capacitors referred to as Stiffening Capacitors. A capacitor is a devise that stores electrical energy. Well, you say that’s what a battery does. Well yes it does, but the difference is the ability and speed that this electrical energy is able to be discharged.

Batteries are designed to store electrical energy for long periods of time. A battery also discharges slowly. A capacitor charges and discharges very rapidly. The reason behind this is due to the internal resistance of both devices. A battery has a high resistance that allows for long-term energy storage and a slow discharge. The capacitor has virtually no internal resistance, which allows for rapid charges and discharges.

An amplifier requires current as music signal passes through it. This creates transient signals in the amplifier. The problem occurs when many of these signal come in rapid succession in a short period of time. The time we are talking about are very small fractions of a second (milliseconds). If your electrical system is unable to react to this it causes a sagging effect in the audio output.

As the current goes up, so must the voltage. Since you can’t increase the voltage as the current requirement increases we get a decrease in voltage and this decrease in voltage causes a sagging power supply. Amplifiers work best at 14.5 volts and can easily overcome a factory installed alternator current output capacity. When the engine is turned off, the system requirements are supplied by the battery increasing the problem of supplying the transient requirements. You could add 10 or 20 more batteries and it wouldn’t help. Remember, as we explained above batteries can’t supply energy quickly enough to supply the transient needs of the amplifier. Please note that these transients may be 100 amps. They occur so fast that your fuse will not be effected, remember this takes place in milliseconds.

By adding a large stiffening capacitor to your amplifier input power line you should be able to meet these transient requirements. Remember as we explained above, a capacitor can store energy very fast and discharge energy very fast. This should solve the transient current requirement to the amplifier.

The voltage of the capacitor can only be the same as the alternator output or if the engine is off, to the level of the battery. So, as you can see a capacitor doesn’t maintain battery levels. If you are still having energy shortages to operate your system you may need to look into a high output alternator.

 

Thanks for adding ScionDad, i know my short answer that any power used has to be supplied back by the alternator was a bit short. But you are dead on about the extra batteries. Power IN = Power OUT in any system.

Good explanation of the capacitor as well. That was what I was try to get across with the filter description, but I may have tried to go a little deep with that one Caps have very low reactance (resistance due to capacititance in this case) to high frequency and very high reactance to low frequency.

So I must ask Scion Dad.... is there a fellow engineering geek in the house ? :p Sounds like you know your stuff.. so I had to ask!

 

https://www.scionlife.com/forums/viewtopic.php?t=48616

 

I've been called a geek (among other things) over the years But mainly I've been working in audio and RF for several decades. Mostly 10K or higher erp equipment in broadcast. You know what your talking about, so I really don't want your resident position by any means. Just bored and figured I'd entertain myself going back in time playing with car audio....man things have changed Actually you have refreshed my memory on several thing since I started reading about some mods here. Thanks

 

I got one up on that man.
Below is an e-mail conversation with Dennis Moore at Mechman.com
It's long but answeres all of my questions when it comes to the alternator issues.
I researched a lot so start from the bottom and read up!
The prices are in bold!!!!!


----------Original Message------------------------------------
From: Dennis Moore [mailto:dennis@mechman.com]
Sent: Tuesday, May 18, 2004 9:47 PM
To: Haylock, Austin M. E4 (BAF)
Subject: RE: 04 Scion xB Car Audio Alternator Issue


I believe your stock alternator is about 100 amps.

Dennis Moore

----------------------------------------------------------------

At 08:05 AM 5/17/2004, you wrote:
Awesome....
I really appreciate you getting back to me.
I will look back into it when I get back to the states.
One last thing and I promise I will quit bugging you.
Do you know what my stock alternator is rated at?
Is it less than your 20-250-43G-1G (150amps)?
Please let me know at your earliest convenience!!!!
Thanks again,
Austin

-----Original Message----------------------------------------------------
From: Dennis Moore [mailto:dennis@mechman.com]
Sent: Monday, May 17, 2004 7:38 PM
To: Haylock, Austin M. E4 (BAF)
Subject: RE: 04 Scion xB Car Audio Alternator Issue


Austin:
It actually was not an experiment. We set the alternator up for a
customer who had sent us the alternator and took a lot of pictures. We then
set all of the information up in a CAD (Computer Aided Drafting) program and
designed the new bracket from there. The shop installed the alternator with out any problems. So we do have a kit for your vehicle. We have three models that will fit your vehicle. First is the 20-250-43G-1G ($392.00) rated @ 150Amps "HOT" (185Amps "COLD") next is the 20-275-43G-1G ($454.00) rated @ 175Amps "HOT" (210Amps "COLD") and last is the 20-300-43G-1G ($534.00) rated @ 200Amps "HOT" (240Amps "COLD"). All three require an adapter bracket kit ($50.00) and an adapter plug ($35.00) for the install. Should you have anymore questions, just call our tech support @ 760-956-7596 or email us. To place an order call 888mechman (632-4626) or email us.

Regards

Dennis Moore
-----------------------------------------------------------------

At 10:08 PM 5/16/2004, you wrote:
Dennis,
That's great. But what type of alternator did you install?
I mean will the alternator that you were experimenting with give me the
amount of power I need to run my system? Is it for sale? Let me know what kind of amperage the alternator puts out and if you recommend it to me? I still have a ton of questions.
Thank you for keeping me posted.
Respectfully,
Austin Haylock

-----Original Message--------------------------------------------
From: Dennis Moore [mailto:dennis@mechman.com]
Sent: Monday, May 17, 2004 9:38 AM
To: Haylock, Austin M. E4 (BAF)
Subject: RE: 04 Scion xB Car Audio Alternator Issue


Austin:
We were able to come up with a mount for the alternator which works
very well.

Regards

Dennis Moore
---------------------------------------------------------------------

At 12:52 AM 5/15/2004, you wrote:
Hello,
Just following up on the Scion alternator issue!
Please let me know if you have come to some kind of a conclusion.
Respectfully,
Austin Haylock

-----Original Message-----------------------------------------------
From: Dennis Moore [mailto:dennis@mechman.com]
Sent: Tuesday, May 04, 2004 8:03 PM
To: Haylock, Austin M. E4 (BAF)
Subject: Re: 04 Scion xB Car Audio Alternator Issue


Austin:
We are currently working on that vehicle and should have an answer
in the next few days.

Regards

Dennis Moore

----------------------------------------------------------

At 10:45 PM 5/2/2004, you wrote:
Sir,
I am into the car audio scene but my current alternator
will not keep up with the demand of draw that my amplifiers put on it.
Can you give me guidance to where I can get a aftermarket alternator that
will be able to keep up with about 300amps of draw that my amplifiers alone will
produce (300amps is the max draw from my amplifiers). For your
information my vehicle is a 04 Scion xB
Please let me know if you can help me out or give me guidance to
where I could obtain this type of alternator.
Thank you so much for your help in advance.
Respectfully,
Austin Haylock

Austin M. Haylock
SrA, USAF
BAF Contracting
DSN: 231-4474

 

Well, papa, I won't add to the theory of caps and alternators because that's been covered pretty thoroughly, and I think even you and I have discussed it once or twice. Instead, I'll just add my touch of real world experience.

All of what you are asking depends upon your usage. If you're gonna have your system bumping without the car on, then the alternator isn't going to do a thing. If you're running with the car engine on, then that's another issue but employment of an upgraded alternator is not always required. Doesn't mean it won't help, just means that, depending upon your goals, it might not be required.

Car 1 - Suzuki Aerio SX
2 RE MT 18's
4 RE XXX 10's
2 Tru SH-1 amps
4 Atomic 1500.1 amps
5 Yellow Tops
25 Farad cap
stock 60 amp alternator
Consistently metered 163.1, no lights dimming, no alt.. problems.

Car 2 (Current) - Scion xA
Complete Alpine/iPod system
1 DD9917 Quad Coil custom built sub
4 Visonik V4000XD modded 5600x1@1 ohm
4 Yellow Tops, adding 4 more
25 Farad cap
Stock alternator
No problems, period

There are alot of opinions on caps, alternators, you name it, but personally I have yet to employ an upgraded alternator and suffered because of it. Doesn't mean you can't or shoudn't, but I am drawing a monsterous amount more power than your system will and I don't have a problem. Note the usage of Yellow Top batteries! And Dom Irragi and I even bounced around the idea of an upgraded alt for this years dbDrag system, but didn't see where it would help with my goals.

And keep in mind, more than likely, you aren't going to push the 1000W RMS to each sub in that enclosure. Due to it's efficiency and tuning for those subs, it's gonna get real loud without alot of power. If you do end up pushing it, you're gonna have some fun for sure.

Kind Regards,
Matt

 

Yeah, I think I enjoy the car audio side of stuff mainly due to it always pushing the technology., that and it is a cool, fun way to put design skills to the test. I have worked more in the automation and application development areas, but have also worked on projects in avionics and patch antenna designs, so I have had some fun in the microwave realm Anyway, good to talk with you!

 

ok im not calling u a liar, but i am finding it hard to belive that a stock alt. can power ALL that stuff and not have any dimming...i mean seriously...my buddy has like 1\4 what u said and his system dims the hell out of his car....im sure u can understand my side of this right?

 

so, after reading all this im still a bit confused all i want is for my damn lights not to dim! what can i do...

 

lol.....um get better lights?

 

Like I said, doesn't mean you don't need one, but it can be done without one. There are alot more variables included here that play into the end results you receive, like the big 3 upgrade, your wiring, etc.

And, remember as I quoted earlier, if your car isn't running, the alternator doesn't do crap. Obviously for SPL most of the heavy usage with my system is with the car off. With 4 Yellow Tops and a 25 farad cap to balance some points out, I have all the reserve time I need. The alternator simply recharges those batteries, nothing more. In fact, alot of competition vehicles use a breaker system that isolates the alternator from the battery anyway. And if you look further into it, each of my amps has the capacity of 400A current draw each. So, if the alternator was everything in every situation (again, not that it's not a valuable addition), then you can do the math yourself to see what size alternator would be required.

When the car is running, I still don't have any issues whatsoever with dimming, but obviously it's not cranking near as hard as if I wasn't in it. And you're right, I see alot of cars with smaller systems that have serious dimming problems. But then again, most of the time they skimp on the big 3 upgrade, proper wiring, and really thinking out designing and implementing their systems, stuff like that.

Kind Regards,
Matt

 

arnt some dB comps done with the engine off anyways? a powerwheel can pull 173 dB with one amp and sub. and that thing doesnt even have an engine!!

 

Yes, depending upon class, some events in different organization have different rules for ccar on/off, etc.

 

Again..... you can add as many batteries and caps that you want to, it will not prevent the alternator for becoming overloaded. If your system plus your vehicle systems need 100 amps to run, then when the car is running the alternator will have to supply 100amps regardless of the number of batteries. If your system and vehicle require more current than the alternator can supply without burning up, then you need a bigger alternator. This is independent of the batteries and caps.

 

but if a car needs 100 amps and your alt cant put out 100 amps doesnt it just take power from the battery

 

In order to charge the system, the alternator must overcome the back emf of the battery (hence the 14.5 V) and supply all of the current used by the system. If you draw 110 amps, and your alternator is rated for less, then you are bound to burn up the alternator as well as have charging issues. Like I metnioned, Power in Equals power out.