what are your opinions? The RMS for the sub is 350 and since the amp never really puts out its 100% of its stated wattage i'm using the US Acoustics 2150 that has 450 watts. hopefully, there won't be clipping? What's the point of adjusting gain (what is gain really)? I read about people that use low power to power their sub and then turn up the gain too high, going beyond what the amp is capable of, thus destroying the sub? could someone verify all this? thanks!
Impedance 4 ohms
Cone Material Aluminum
Surround Material Butyl rubber
Sealed Box Volume (cu ft) 1
Ported Box Volume (cu ft) 1.75
Port diameter (inches) 4
Port length (inches) 12.33
Free-Air Yes
Dual Voice Coil No
Sensitivity 96dB
Frequency Response 18 - 0.2k Hz
RMS Power Range (Watts) 75-350
Peak Power Handling (Watts) 1400
specs for amp:
RMS Power Output (Watts x Channels) 150 x 2
THD at Rated RMS Power 0.01%
Signal to Noise Ratio 105 dB
Input Voltage 12.9v
Power at 2 Ohms (Watts x Channels) 225 x 2
Bridged Power (Watts x Channels) 450 x 1
Minimum Impedance Bridged 4
Minimum Impedance Unbridged 2
Amplifier Class AB
Tri-Way Capable Yes
Low-Pass Crossover Frequency 40-460Hz
Low-Pass Slope (dB/octave) 24dB
Bass Boost 0-18dB
Bass Boost Frequency 40Hz
Fuse Rating 30 x 2
Speaker Level Inputs Yes
Preamp Outputs No
as for clipping....
You can think of the speaker signal as a single sine wave (which it is, if you're playing a solid test tone). Just picture this clean sine wave in your head, this is what it looks like on it's way from the headunit to the amp. The amp jacks up this sine wave and makes it MUCH larger, while still keeping it clean, then it sends it to the sub. The level it increases the amplitude of the wave is dependant on the gain knob on the amp. As you turn up the gain the amplifier amplifies the signal more and more, up to a point. This point is where the amp starts to clip. Basically an amp has barriers, just think of that graph of the sine wave and these barriers are just flat walls above and below the wave. So you're turning up the gain, the wave gets larger and larger until it hits these barriers. As you pass the barrier it just cuts off everything that goes past it and flattens off the wave. An insanely clipped signal would look like a square wave, just to give you an idea.
The spot it starts clipping is dependant on the amp, but it generally starts just above it's rated power, so as you try and make the amp work harder it just cuts off the wave and makes it distorted. Obviously this is very hard on the woofer, slight clipping isn't too bad, but as it gets worse it can be very detrimental to the life of the sub as well as the amp. This is why it's important to get an amp that puts out more power than you need, so you can keep the gain set so you're still under the limits of the amp and it's loud enough for you. If you get an amp that's too small you will have to turn the gain up and up and drive the amp into clipping just trying to get the amount of power out of it that you want. The ugly distorted wave that comes out takes it's toll on the sub and cuts it's life short.
Clipping can be hard to hear when you're playing music, but it's very easy to spot if you're playing test tones. You just play a solid tone through your system and slowly turn up the gain until you can hear the pitch change, then you turn it back down slightly and you're set. If you use an amp that is more powerful than the sub can take you can't do this though as you risk blowing the sub, you just have to watch and listen to your sub carefully to learn it's limits.
That helps a lot. Thanks. In the previous response you asked for the impedance. How is that related in answering the question I had earlier? I know it’s measured in ohms, but I don't know if more resistance is better or not? I'm not familiar with that concept.
all my classes this sem just ended so I'm in a good mood and I have nothing to do, so here it goes, lol
Resistance is exactly what it's name implies, it is the electical component's resistance to current. With anything in electricity, a voltage is applied across an object, whether it's a resistor, capacitor, inductor, speaker, whatever. Depending on what the resistance is, a current flows through as a result. The relationship is very simple: V=IR, or the voltage applied is equal to the current that flows through multiplied by the resistance of the object. A higher resistance means less current flows and a lower resistance means more current flows. The 2 extremes can give you an idea of how this works. Say you have a car battery just sitting there, there is a voltage difference between the + and - terminals but no current flows between them because the only thing connecting them is air floating around the room. I=V/R, if the resistance is infinite like in this example, then the current is 0. Say you take a wire and connect the 2 terminals together, now your resistance is VERY small so a hell of a lot of current flows through the wire, and it will probably melt the wire fairly quickly as the heat builds up and bad things happen.
Speakers are no different, minus a couple complications they are essentially a resistor in a circut where the amplifier is the battery. The amp puts out a certain voltage relative to it's power (refer to the other book of a post above this one, lol), this equation is also extremely simple: P=IV or P=V^2/R (so an amp that puts out 100 watts at 4ohm, will put out 20V at its terminals. This voltage is applied across the terminals of the speaker and, depending on the resistance of the speaker, a certain amount of current flows as a result. So if you have an amp that puts out 20V from its terminals and you attach a 4ohm speaker to it, 5amps of current will flow out of the amp...it's all pretty simple. Obviously if you hook up a speaker with a higher impedence (impedence is just a form of resistance), less current will flow giving you less power, and if you hook a speaker with a lower impedence more current will flow and you get more power. Unfortunately, amps can only handle a certain amount of current before things start to melt and fry inside the amp. The amount they can take depends completely on the amp. All amps will have a minimum impedence that they are rated at, this depends on how much current they can handle. Hooking a speaker with an impedence lower than this value will cause too much current to be pulled from the amp and things will go downhill from there. If you hook an impedence larger than this number nothing is bad, you just can't pull the most amount of power possible from the amp. It's normally best to match up your speaker impedence with the lowest impedence possible on the amp so you can extract the most power from the amp while still keeping it happy.
Your sub is 4ohm, and that amp you posted puts out the most amount of power at 4ohm and can't handle a load any lower than this, so they are a perfect match for each other. This (and power) is really the only thing you need to look for when picking an amp for your sub or vice versa.
thanks a bunch! i'm planning ahead for the amp install but I wondered what do you use to drill a hole in (the type of drill, material)? should i drill into the board that covers the spare tire well (or is that not sturdy enough)? any specific type of screw is good?
Linear Mode
