Mostly, though, amplifiers don't consume nearly that much power, even under peaks, and it's a lot of marketing wank. This is reflected in the shitty construction of poorly verified consumer "capacitors", which may often be Matryoshka designs. Smaller example:
You can get proper electrolytic or "super" type capacitors, in sizes and ratings suitable for supplying a very large amplifier (many kW) from a modest automotive electrical system (battery and alternator, both suitably sized -- at this rate, you may have two or more batteries wired in parallel, and your alternator will probably be upsized a few times from the usual). Beware of poor imitations, though; and, remember this: if you can't tell an objective difference (i.e., measuring the clipping point on loud music), you're better off saving the money.
Tim
What about getting rid of that dimming of all the lights in your car every time the bass drum fires off at 500watts to 1kw. I could have sworn that placing a 10F cap at the high power amp input smooths this out to a flatter load on your car's electrical system.
It's peaking during the bass drums.
The woofers are 4 ohm, but you already know that the amps have step-up DC-DC converters. Though they regulate and filter the power, they do not have any big caps in them. This means the DC12v side gets nice, counting for losses in the conversion, 100 amp spikes at every strike, or, low frequency bass drive. No 10f cap see the 100 amp sag every beat. 10f cap smooth out the sag to a constant 10amp load, slowly going up to 50 under demanding situations, slowly lowering down. No matter what you think the impedance of the battery and alternator, with the car electronics drawing today around 10 amps, with a 100 amp spike around 60 to 140 shots a minute, you see that dynamic load as the battery goes from 13.8v down to around 12v and back up.
It is healthier for your cars batter and alternator to see a smoother 10-25amp load instead of these continuous 100-200amp spikes 60-140 times a second. Even though the amp may still work fine under both situations.
And if you don't think people put that much power into cars, attached is a photo of a few more than 2kw subwoofer system, not including the rest of the speakers. Ok, so these guys need additional car batteries and additional alternators.
And these systems are small compared to 1 killer 20kw install I saw at CES. It was in a modern station-wagon type car, where all of the rear was nothing but sub-woofers facing vertically up. When running, it lifted the car up&down on it's suspension.
The last image is a 2kw car audio amp. As you can see, there is not a lot of room for huge caps.
Do people ever run those killer stereos when driving with the volume turned up?
The car stereo comment was just an example. My car stereo is just fine and I value my hearing; when I was a kid I had car amps that had their own 1F caps (not all "marketing wank", for this set up, the car would stall on big base hits without them, and I killed the alternator in a month, the battery was in the trunk and wired with 4ga wire) this was in the 1990s before super caps, when everyone was upgrading their tape decks to CD players because the DIN shape was universal. I know for a fact I damaged my hearing; the bass dB was measured over 100, tweeters could go to 130. I would blow 60 Amp fuses so I know you can pull some AMPs.
So you could replace the whole 1F electrolytic with for example 1F @3V caps (is $5.00USD a real price?) if you had 15 of them ($75 is still less then a good brand name electrolytic); five in series then three banks of five wired in parallel? I don't know what they cost but the size savings and the ability to run very short leads to the amp seems like it would be worth it. Seems crazy to put 1F of energy over those little leads. The electrolytics would weld/explode stray bits of copper wire, not much thinner then those leads, when the terminals were crossed by accident.
That is insane.
Anyway of course to beat that someone just has to get a pick up truck and turn the whole bed into a giant woofer + resonator assembly.
And to beat that just get a cargo container and turn it into a giant speaker aray and attach it to a tractor trailer.
And to beat that.....
That is insane.
Anyway of course to beat that someone just has to get a pick up truck and turn the whole bed into a giant woofer + resonator assembly.
And to beat that just get a cargo container and turn it into a giant speaker aray and attach it to a tractor trailer.
And to beat that.....
The car stereo comment was just an example. My car stereo is just fine and I value my hearing; when I was a kid I had car amps that had their own 1F caps (not all "marketing wank", for this set up, the car would stall on big base hits without them, and I killed the alternator in a month, the battery was in the trunk and wired with 4ga wire) this was in the 1990s before super caps, when everyone was upgrading their tape decks to CD players because the DIN shape was universal. I know for a fact I damaged my hearing; the bass dB was measured over 100, tweeters could go to 130. I would blow 60 Amp fuses so I know you can pull some AMPs.
So you could replace the whole 1F electrolytic with for example 1F @3V caps (is $5.00USD a real price?) if you had 15 of them ($75 is still less then a good brand name electrolytic); five in series then three banks of five wired in parallel? I don't know what they cost but the size savings and the ability to run very short leads to the amp seems like it would be worth it. Seems crazy to put 1F of energy over those little leads. The electrolytics would weld/explode stray bits of copper wire, not much thinner then those leads, when the terminals were crossed by accident.A 15V rating for a car electrical system is marginal. I'd go for 20V or more.
Still, I'd look at using thicker wire, upgrading the battery (perhaps another one in parallel with the amp?) and alternator before adding a capacitor.
What's the ESR of those super capacitors? It has to be less than that of the car battery and the wiring to make any difference.
A big, industrial PSU filter capacitor is probably your best bet, rather than those crappy audiophool ones with LEDs on it.
Low ESR will probably be better than more capacitance. Looking at what TDK, Kemet and Vishay have to offer. I'd go for a 25V 0.47F unit with 3mOhm.
http://www.farnell.com/datasheets/2045972.pdf?_ga=1.141165815.47418993.1417808164
http://www.farnell.com/datasheets/2259605.pdf?_ga=1.173632486.47418993.1417808164
http://www.farnell.com/datasheets/2280822.pdf?_ga=1.173682662.47418993.1417808164
Do people ever run those killer stereos when driving with the volume turned up?
What about getting rid of that dimming of all the lights in your car every time the bass drum fires off at 500watts to 1kw. I could have sworn that placing a 10F cap at the high power amp input smooths this out to a flatter load on your car's electrical system.How do you get that kind of power level?
Are you talking about RMS or peak?
Assuming 1kW peak, 500W RMS, you'd need any of the following:
1) A single 0.144Ohm subwoofer. I've never seen such a beast. The lowest commonly available impedance is 4R.
2) An array of 28, 4Ohm woofers. Seems crazy but doable, although most amplifiers aren't designed to drive such a load, so perhaps one amp per speaker.
3) A boost converter, to power the amplifier with 63.25V (more to account for losses in the amp) and drive a 4R load.
#3 is probably the most sensible, as amplifiers designed to run from these sorts of voltages are widely available and a DC-DC converter is easily doable. As it's not necessary to provide this kind of power continuously, the boost converter needn't be designed for 1kW RMS. It can easily be designed for 500W or less and it should have adequate decoupling provided on the secondary side. It should also continue to supply the same output voltage, in spite of any dips in the input voltage.
Lastly, normally car batteries have an internal resistance of under 10mOhm, which should give a voltage drop of 833mV with a 1kW load. When the engine is running, you have the alternator in parallel with that, so the total impedance should be much lower. If the voltage is dropping by significantly more than that, then you need a new battery, alternator or the wiring is poor.
What about getting rid of that dimming of all the lights in your car every time the bass drum fires off at 500watts to 1kw. I could have sworn that placing a 10F cap at the high power amp input smooths this out to a flatter load on your car's electrical system.How do you get that kind of power level?
Are you talking about RMS or peak?
Assuming 1kW peak, 500W RMS, you'd need any of the following:
1) A single 0.144Ohm subwoofer. I've never seen such a beast. The lowest commonly available impedance is 4R.
2) An array of 28, 4Ohm woofers. Seems crazy but doable, although most amplifiers aren't designed to drive such a load, so perhaps one amp per speaker.
3) A boost converter, to power the amplifier with 63.25V (more to account for losses in the amp) and drive a 4R load.
#3 is probably the most sensible, as amplifiers designed to run from these sorts of voltages are widely available and a DC-DC converter is easily doable. As it's not necessary to provide this kind of power continuously, the boost converter needn't be designed for 1kW RMS. It can easily be designed for 500W or less and it should have adequate decoupling provided on the secondary side. It should also continue to supply the same output voltage, in spite of any dips in the input voltage.
Lastly, normally car batteries have an internal resistance of under 10mOhm, which should give a voltage drop of 833mV with a 1kW load. When the engine is running, you have the alternator in parallel with that, so the total impedance should be much lower. If the voltage is dropping by significantly more than that, then you need a new battery, alternator or the wiring is poor.Sorry, but I have to correct you there. 4Ohm is actually the HIGHEST commonly available for mobile audio, as just about all mobile audio electronics are designed for speakers of 4 ohms or less. Home audio, on the other hand, is usually designed for 8ohm speakers. When you get into competition grade speakers you can find them as low as .5ohm (possibly even lower) per coil with as many as 4 coils per subwoofer. High current amps can often power .25ohm loads without a problem. Back when I used to compete in dB Drag and USAC events I had 1200 watts RMS pushing a .75ohm load. Automotive voltage is actually around 14.4v, not 12v.
The car stereo comment was just an example. My car stereo is just fine and I value my hearing; when I was a kid I had car amps that had their own 1F caps (not all "marketing wank", for this set up, the car would stall on big base hits without them, and I killed the alternator in a month, the battery was in the trunk and wired with 4ga wire) this was in the 1990s before super caps, when everyone was upgrading their tape decks to CD players because the DIN shape was universal. I know for a fact I damaged my hearing; the bass dB was measured over 100, tweeters could go to 130. I would blow 60 Amp fuses so I know you can pull some AMPs.
So you could replace the whole 1F electrolytic with for example 1F @3V caps (is $5.00USD a real price?) if you had 15 of them ($75 is still less then a good brand name electrolytic); five in series then three banks of five wired in parallel? I don't know what they cost but the size savings and the ability to run very short leads to the amp seems like it would be worth it. Seems crazy to put 1F of energy over those little leads. The electrolytics would weld/explode stray bits of copper wire, not much thinner then those leads, when the terminals were crossed by accident.A 15V rating for a car electrical system is marginal. I'd go for 20V or more.
Still, I'd look at using thicker wire, upgrading the battery (perhaps another one in parallel with the amp?) and alternator before adding a capacitor.
What's the ESR of those super capacitors? It has to be less than that of the car battery and the wiring to make any difference.
A big, industrial PSU filter capacitor is probably your best bet, rather than those crappy audiophool ones with LEDs on it.
Low ESR will probably be better than more capacitance. Looking at what TDK, Kemet and Vishay have to offer. I'd go for a 25V 0.47F unit with 3mOhm.
http://www.farnell.com/datasheets/2045972.pdf?_ga=1.141165815.47418993.1417808164
http://www.farnell.com/datasheets/2259605.pdf?_ga=1.173632486.47418993.1417808164
http://www.farnell.com/datasheets/2280822.pdf?_ga=1.173682662.47418993.1417808164
Two batteries rarely helps like a cap does. I tried that once, it was just big, heavy, and more expensive. Plus mounting it wasn't easy, took up lots of space and you have to make sure you have a place for it to leak onto. Replacing the wires with thicker ga can be a nightmare with the complexity of car wiring harnesses and trying to make things fit through holes that are already filled with wires. Upgrading the alternator is going to cost a few hundred assuming a bigger one could be just bolted on, most cant be and will require machining parts and possibly rerouting belts. Putting a cap in the trunk is just two wires and tie strap. Always try the cap first, do what easiest and cheapest before getting overly complex. No offense but have you ever worked on automotive electrical or installed a high current system in a car? It seems super simple just +12V and gnd, how hard can it be? But making everything look stock and having it fit all nice an neat with no panel gaps while balancing space and sound is a challenge. Also trying to keep down alternator noise and rattles/ rod noise can also be a huge head ache when you are trying for very accurate sound.
And anyways the car audio comment was just an example to compare size in an application. I have no plans to alter my stock car stereo, unless you are telling someone else to upgrade their wires?
What about getting rid of that dimming of all the lights in your car every time the bass drum fires off at 500watts to 1kw. I could have sworn that placing a 10F cap at the high power amp input smooths this out to a flatter load on your car's electrical system.How do you get that kind of power level?
Are you talking about RMS or peak?
Assuming 1kW peak, 500W RMS, you'd need any of the following:
1) A single 0.144Ohm subwoofer. I've never seen such a beast. The lowest commonly available impedance is 4R.
2) An array of 28, 4Ohm woofers. Seems crazy but doable, although most amplifiers aren't designed to drive such a load, so perhaps one amp per speaker.
3) A boost converter, to power the amplifier with 63.25V (more to account for losses in the amp) and drive a 4R load.
#3 is probably the most sensible, as amplifiers designed to run from these sorts of voltages are widely available and a DC-DC converter is easily doable. As it's not necessary to provide this kind of power continuously, the boost converter needn't be designed for 1kW RMS. It can easily be designed for 500W or less and it should have adequate decoupling provided on the secondary side. It should also continue to supply the same output voltage, in spite of any dips in the input voltage.
Lastly, normally car batteries have an internal resistance of under 10mOhm, which should give a voltage drop of 833mV with a 1kW load. When the engine is running, you have the alternator in parallel with that, so the total impedance should be much lower. If the voltage is dropping by significantly more than that, then you need a new battery, alternator or the wiring is poor.Sorry, but I have to correct you there. 4Ohm is actually the HIGHEST commonly available for mobile audio, as just about all mobile audio electronics are designed for speakers of 4 ohms or less. Home audio, on the other hand, is usually designed for 8ohm speakers. When you get into competition grade speakers you can find them as low as .5ohm (possibly even lower) per coil with as many as 4 coils per subwoofer. High current amps can often power .25ohm loads without a problem. Back when I used to compete in dB Drag and USAC events I had 1200 watts RMS pushing a .75ohm load. Automotive voltage is actually around 14.4v, not 12v.Yes, the unloaded voltage on a car's electrical system is 14.4V, when the engine is running. It will be much lower, with the engine off or with a large load.
Where do you get drivers with such a low impedance from? I've had a Google and can't find much below 4Ohm.
A quick search found https://www.parts-express.com/audiopulse-ax12q1-axis-12-quad-coil-subwoofer--293-620 had quad 1 ohm subs.
A quick search found https://www.parts-express.com/audiopulse-ax12q1-axis-12-quad-coil-subwoofer--293-620 had quad 1 ohm subs.It says it's rated for 2500W RMS but for how long?
There's no way you can put that much power into something that size continuously, with no cooling fan and not cook it.
Why can't they be honest about the specification?