Capacitors

[DRD-00F]

Ive got 3000 watts rms, but im only using about 1100 or so... i also have a Delkor battery so power isn't an issue... but the flow of that power may be...

I have seen less powerful systems with 1 farad capacitors... and i was always pretty certain that i wouldn't need a capacitor, which is still the side im on...

my question is, how will i know if i need a capacitor?

[Fhrx]

The two main issues faced by high power audio systems these days are power delivery (including earthing) and power storage (including batteries and capacitors).

1. Power delivery.

In a DC system you need to make sure your cables are of adequate size and that all the earths have been upgraded accordingly. Electrons will not leave the negative terminal if they cannot flow back to the positive. Therefore the cables should be the first angle of attack.

2. Power storage.

The main fundamental difference between high quality batteries and capacitors is that batteries generate charge from a chemical reaction whereas capacitors simply store charge. Both can discharge quite fast (although the cap is fastest), both can smooth out voltage, both can supply plenty of power to your amplifier when its needed however the battery is generally the cheaper option and indeed the one we recommend first. The battery will also hold more reserve charge too allowing you to run your system for longer when the car is not running.

The short conclusion; get a quality deep cycle battery and make sure the cables are adequate. That should provide your system with enough power taking into consideration the scenario you have listed above.

Edited April 16, 2007 by Fhrx

[Primordial]

What model is your amp Steve?

Some of those Earthquake amps have 0 gauge terminals on them. Maybe the 4 gauge will be too small as well!

[DRD-00F]

PHD5000WD/1

though technically its a J class amp i believe...

i dont have a problem as of yet, but theres a good chance i will in the future if i ever get a chance to utilise all that power... everything in the boot at the moment is temporary til i design a boot that im happy with... which so far hasn't gone so well i may have to make some sacrifices and be less original then i want to be...

people highly underestimate wire sizes... its got 8 gauge out of the amp into the subs... trust me, that is plenty... ive run some powerful temporary systems on really bitch wire for some time... it was that or nothing... each time it has held up fine...

[Primordial]

PHD5000WD/1

though technically its a J class amp i believe...

i dont have a problem as of yet, but theres a good chance i will in the future if i ever get a chance to utilise all that power... everything in the boot at the moment is temporary til i design a boot that im happy with... which so far hasn't gone so well i may have to make some sacrifices and be less original then i want to be...

people highly underestimate wire sizes... its got 8 gauge out of the amp into the subs... trust me, that is plenty... ive run some powerful temporary systems on really bitch wire for some time... it was that or nothing... each time it has held up fine...

I'd do some research before using 8 gauge on a system that you've spent thousands of dollars on... The smaller the wire, the higher the resistance on the system. If you're pushing the limits of the amp, the thinner wire will put even more strain on the system. Hell yeah it'll work, but you will find that the amp will overheat much quicker, and you will be losing a percentage of your possible wattage output! The difference between the wire thickness is this:

4ft Length 8 gauge @ 2000WRMS / 2 OHM 1 Channel - 242WRMS (12%) LOSS due to wire resistance

4ft Length 2 gauge @ 2000WRMS / 2 OHM 1 Channel - 66WRMS (3%) LOSS due to wire resistance

So you can see, the difference is 11%. For maybe an extra $60 in power wire, having an extra 11% power and 11% more of a buffer when it comes to overloading/overheating the amp sounds like a good deal... Especially when you've spent probably close to $1500 on the amp alone!

Have a play with this to do some calculations for your own system:

http://www.rockfordfosgate.com/rftech/wire_calculator.asp

[DRD-00F]

thats good and all, but as for now, I'm not utilising anything near what that amp can do... i keep saying everything in the boot is temporary

i plan on having 4 or 2 gauge out of the amp to a power distribution block () then either 4 or 8 to the subs... these things are stable down to .5Ω's kinda handy when you have 2 dual voice coil subs off a mono block

at the moment, the weak point in this system is the 500watt subs... even with heat and size resistance, they still cant handle whats coming to them...

oh, another weak point is the boot... it flexes a lot... and my head... that hurts sometimes...

i have to choose 2 new subs now as well... i was originally going to go with 2 15' subs, but these boots arn't that big and it would be VERY impractical to have what i want...

-Subzero-15

- 2500W peak

- 1250W RMS

- Recommended sealed enclosure range: 3 to 3.5 feet cubed

Features

- Over 4" long throw excursion

- 3" High Temp flat wire dual (2x4ohms)

- Dual Nomax / Romax spider construction

- 8 gauge speaker connections

--Mounting Depth 7.5"

get two of those together in a dual slot port box and you need a lot of room im thinking about going down to the 12 inches... its only 1000W though...

would LOVE the HoLee-S though... its f**ken nuts!

# SPECS

# Sensitivity 85.0 dB

# Qts .338

# Fo 25.475 Hz

# 15,000 Watts Peak

# 7000 Watts RMS each coil

# Over 4" long throw excursion

# Dual (2x1ohms) 4" x 8" High Temp military grade flat wire voice coil.

# (4)Quad Nomax / Romax spider construction

# 8 gauge speaker connections

# 112lbs.

# Recommended Enclosure

# 6-10 Cu Ft 1" MDF Minimum

# Port Surface 107.25 sq in

# Port Length 18.5" Depending on the tuning frequency

not in this car

got any other subs you wanna suggest? go nuts