Jump to content

Sign in to follow this  

Recommended Posts

I meant at very worst not really all the time. Thats why i say would a cap like this fosgate help me as far as an audible difference.

Plus dropping to that may not be ideal but its safe anyways.

  • Like (+1 Rep) 1

1st Setup(SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 Audioque SDC2.5 15 subs8.7 cubes at 37hz build DONEAudioque 1200d (Audioque 1200d Sold, similar performance to my ap1500)Diamond Audio Hex 6.5 Mids n TweetsCerwin Vega Exl 400 4 channel Bridged(also have MTX 4004 not being used)1 Run of power Knu Fleks 4 Gauge2 Cheap stock Battery setup2nd Setup (SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 15 Kicker cvx (maybe two SA 15 in future)7 cubes net tuned at 34hzAlphasonik Old school 1600rms (ap 1500d sold GREAT Budget amp)JBL 6.5 Power Series Components, Infinity Kappa 6.5 3 ways, and 2 Kicker KS Tweets (LOUD)Cerwin vega exl4001 run knu Fleks OFC 0 gaugeBig 3 done1 Odyssey 1500, 1 optima yellow top d31

Share this post


Link to post
Share on other sites

Is this a qualtiy cap?

Yeah also want to know this.

I sold one a few months back without ever even trying it on any system ive done since i always went with the caps suck theory without trying it myself.

My girls truck drops as low as 12.3v-13.3 at full tilt on 1000rms and this is with stock alternator and 1 stock battery and i wonder if this would of done something good to this system since her voltage is pretty good.

dropping to 12.3 isn't good. its ideal to not drop below 14v.

What if the amp is rated at 12 volts?


I don't put images in my signature to let people know I mean business.

Share this post


Link to post
Share on other sites

Not sure what your trying to ask but the amp along with the rise in ohms and drop in voltage is not going to ever do fully rated since amps are mostly rated at 14.4v which you never usually can fully achieve(in most daily systems).

Im saying the amp is safe as far as electrically and will not ruin it just because it drops to 12.3 sometimes, it just wont do fully rated but thats a given anyways with box rise and stuff, plus to my ear there is no difference in power from12.3v to the higher 13's and stuff.

Pm me instead so we wont ruin this great thread.

Edited by teamace24

1st Setup(SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 Audioque SDC2.5 15 subs8.7 cubes at 37hz build DONEAudioque 1200d (Audioque 1200d Sold, similar performance to my ap1500)Diamond Audio Hex 6.5 Mids n TweetsCerwin Vega Exl 400 4 channel Bridged(also have MTX 4004 not being used)1 Run of power Knu Fleks 4 Gauge2 Cheap stock Battery setup2nd Setup (SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 15 Kicker cvx (maybe two SA 15 in future)7 cubes net tuned at 34hzAlphasonik Old school 1600rms (ap 1500d sold GREAT Budget amp)JBL 6.5 Power Series Components, Infinity Kappa 6.5 3 ways, and 2 Kicker KS Tweets (LOUD)Cerwin vega exl4001 run knu Fleks OFC 0 gaugeBig 3 done1 Odyssey 1500, 1 optima yellow top d31

Share this post


Link to post
Share on other sites

Is this a qualtiy cap?

Yeah also want to know this.

I sold one a few months back without ever even trying it on any system ive done since i always went with the caps suck theory without trying it myself.

My girls truck drops as low as 12.3v-13.3 at full tilt on 1000rms and this is with stock alternator and 1 stock battery and i wonder if this would of done something good to this system since her voltage is pretty good.

dropping to 12.3 isn't good. its ideal to not drop below 14v.

What if the amp is rated at 12 volts?

find an amp that cant handle 14volts


t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

Share this post


Link to post
Share on other sites

Is this a qualtiy cap?

Yeah also want to know this.

I sold one a few months back without ever even trying it on any system ive done since i always went with the caps suck theory without trying it myself.

My girls truck drops as low as 12.3v-13.3 at full tilt on 1000rms and this is with stock alternator and 1 stock battery and i wonder if this would of done something good to this system since her voltage is pretty good.

dropping to 12.3 isn't good. its ideal to not drop below 14v.

What if the amp is rated at 12 volts?

find an amp that cant handle 14volts

?

Does it drop to 12.x for extended periods or just for a second or two?

Share this post


Link to post
Share on other sites

I check the voltage at the amp like once a week or two. It never really drops below 13 and thats where its at usually.

Low 12's is only rarely so thats why i was asking what a farad cap can do to the system. The only real time voltage concerns me in any system is when it hits the 11's and lower not the 12.5 and higher thats still safe for the amps.

Edited by teamace24

1st Setup(SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 Audioque SDC2.5 15 subs8.7 cubes at 37hz build DONEAudioque 1200d (Audioque 1200d Sold, similar performance to my ap1500)Diamond Audio Hex 6.5 Mids n TweetsCerwin Vega Exl 400 4 channel Bridged(also have MTX 4004 not being used)1 Run of power Knu Fleks 4 Gauge2 Cheap stock Battery setup2nd Setup (SOLD):2007 GMC YukonPioneer Avic F90bt

Audiocontrol Epicenter2 15 Kicker cvx (maybe two SA 15 in future)7 cubes net tuned at 34hzAlphasonik Old school 1600rms (ap 1500d sold GREAT Budget amp)JBL 6.5 Power Series Components, Infinity Kappa 6.5 3 ways, and 2 Kicker KS Tweets (LOUD)Cerwin vega exl4001 run knu Fleks OFC 0 gaugeBig 3 done1 Odyssey 1500, 1 optima yellow top d31

Share this post


Link to post
Share on other sites

Honestly, the more the merrier. Maybe that 10 farad rockford cap I posted earlier? If it drops to that for a split second then comes back up, that's where I think you will find a cap useful, assuming that you can hold your voltage outside of those dips

Share this post


Link to post
Share on other sites

Amplifiers already have capacitors in them to account for sudden spikes in current draw.

Amps have caps in them, but not for that. The power supply side has basically 2 sets of caps, typically smaller value but low ESR electrolytics on the primary side of the power supply (nearest the B+ terminal of the amp usually), and then large general purpose electrolytics on the secondary side of the power supply (the high voltage side that feeds the output section). The caps on the primary side are to keep noise from the amplifier switching on and off (the power supply doesn't draw current in a continuous manner from the car, it's actually drawing pluses of current at around 50 thousand times a second) from getting into the cars electrical system from the amplifier, and also to ensure the power supply has enough energy stored up to "take a drink" once every 1/50,000ths of a second. The larger caps on the secondary side are to filter out the high voltage pulses of energy that are coming from the power supply at 50kHz and turn them into DC.

  • Like (+1 Rep) 1

Share this post


Link to post
Share on other sites

J=CV^2 (J= joules, C=capacitance, V=voltage)

for a 1 farad capacitor on a system charging at 14.2 (voltage = random number somewhere around normal car voltage I pulled out my ass for the sake of this post)

J = 1 x (14.2x14.2)

J = 201.64

ok lets round that to 200

ok so 1 joule = 1 watt for 1 second.

now lets play with those numbers.

we all know amplifiers aren't perfect, power is lost to heat, etc. a pretty common number to see is 70% efficiency at 1 ohm on a class D amp.

lets say you're the typical sort of SMD person. you want bass. you want it in your face, you like the long drawn out demo music, low notes, etc.. you stive for a big, powerful system.

so lets start the number game at 5000 watts, at 70% efficiency, that amp needs 7142 watts of input.

and remember from before, 1 farad = roughly 200 joules = 200 watts at 1 second.

7142 / 200 = 35.71 . round it up to keep from getting bogged down. 36

so that's 36 joules if the amp is operated for 1 second.

lets keep playing with the numbers cause 36 farads is a ridiculous number for 1 second of play.

say you put a nice single 275 amp alt under the hood, that charges at the 14.2 as we started this whole thing out at.

wattage = voltage x amperage

275 x 14.2 = 3905 watts from the alternator

bare minimum to run the car itself is say.. 60 amps or (60x14.2=852) call it 900 watts for overhead.

so we got.. call it 3000 watts left for the system

7142 - 3000 = 4142 watts still needed for the system

4142 watts @ 1 second = 4142 joules / 200 = 20.71 call it 21 farads needed.. per second

still haven't taken batteries into the equation here but we'll leave them out of this for now.

ok so 21 farads per second, for 30 seconds of a bass race 630 farads.

So who's buying me a 630 farad capacitor bank?

Corrected version:

J=(CV^2)/2 (J= joules, C=capacitance, V=voltage)

for a 1 farad capacitor on a system charging at 14.2 (voltage = random number somewhere around normal car voltage I pulled out my ass for the sake of this post)

J = 1 x (14.2x14.2) / 2

J = 100.82

ok lets round that to 100

ok so 1 joule = 1 watt for 1 second.

now lets play with those numbers.

we all know amplifiers aren't perfect, power is lost to heat, etc. a pretty common number to see is 70% efficiency at 1 ohm on a class D amp.

lets say you're the typical sort of SMD person. you want bass. you want it in your face, you like the long drawn out demo music, low notes, etc.. you stive for a big, powerful system.

so lets start the number game at 5000 watts, at 70% efficiency, that amp needs 7142 watts of input.

and remember from before, 1 farad = roughly 100 joules = 100 watts at 1 second.

7142 / 100 = 71.42 . round it up to keep from getting bogged down. 72

so that's 72 Farads if the system was able to use the entire amount of energy stored in the capacitor, but it is not because the lowest voltage the system will hit during the amplifier's operation isn't zero volts. Let us say the system voltage drops to 10V during a burp. So then the math for the useable energy stored in the capacitor actually looks like this:

Usable joules = ((farads x charging voltage ^2) / 2) - ((farads x minimum voltage ^2) / 2). So now we know the 1 farad cap in this example actually contains (((1 x 14.2^2) / 2) - ((1 x 10^2) /2)) joules. or 50 Joules that are usable. The other 50 are stuck in the capacitor and can't get out unless the system voltage dropped to zero. So actually we can only get 1/2 the energy out and thus we need 144 Farads

lets keep playing with the numbers cause 144 farads is a ridiculous number for 1 second of play.

say you put a nice single 275 amp alt under the hood, that charges at the 14.2 as we started this whole thing out at.

wattage = voltage x amperage

275 x 14.2 = 3905 watts from the alternator

bare minimum to run the car itself is say.. 60 amps or (60x14.2=852) call it 900 watts for overhead.

so we got.. call it 3000 watts left for the system

7142 - 3000 = 4142 watts still needed for the system

4142 watts @ 1 second = 4142 joules / 50 = 82.84 call it 83 farads needed.. per second

still haven't taken batteries into the equation here but we'll leave them out of this for now.

ok so 83 farads per second, for 30 seconds of a bass race 2485 farads.

So who's buying me a 2500 farad capacitor bank?

  • Like (+1 Rep) 1

Share this post


Link to post
Share on other sites

Amplifiers already have capacitors in them to account for sudden spikes in current draw.

Amps have caps in them, but not for that. The power supply side has basically 2 sets of caps, typically smaller value but low ESR electrolytics on the primary side of the power supply (nearest the B+ terminal of the amp usually), and then large general purpose electrolytics on the secondary side of the power supply (the high voltage side that feeds the output section). The caps on the primary side are to keep noise from the amplifier switching on and off (the power supply doesn't draw current in a continuous manner from the car, it's actually drawing pluses of current at around 50 thousand times a second) from getting into the cars electrical system from the amplifier, and also to ensure the power supply has enough energy stored up to "take a drink" once every 1/50,000ths of a second. The larger caps on the secondary side are to filter out the high voltage pulses of energy that are coming from the power supply at 50kHz and turn them into DC.

I stand corrected.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...