Will my speakers blow if I bridge them?

I have 2 12" visonik subwoofers that are 1000 watts rms or 500 each. The amp that came with them is 400 watt rms but I think it's supplying less than 100 watts to each sub.

I want to know the difference between bridging subs and bridging an amp. Is it the same thing?

Secondly, if k bridge my set up for mono, will I blow my amp and/or speakers? Let's just say my amp has a 10 amp fuse I think.


2 Answers

  • KaeZoo
    Lv 7
    9 years ago
    Favorite Answer

    Bridging an amp means combining two channels into a single channel with more power. There's no such thing as bridging a sub, but people often use this term as a synonym for wiring subs in parallel.

    By definition, you can't bridge a mono amplifier; only a 2-channel or 4-channel amp.

    With a 2-channel amp, you have to be careful of the impedance. If your amp is 2-ohm stable in 2-channel mode, then it's only 4-ohm stable in bridged mode. If you have two 4-ohm, single voice coil subs and you wire them in parallel to the bridged amp, then you'll have a 2-ohm load and could damage the amplifier.

    If your amp really only has a 10-amp fuse, it's not a 400 watt amp, or anywhere close to it. It's probably closer to 100 total watts RMS, and it may not be bridgeable at all. Check the owner's manual.

  • 9 years ago

    KaeZoo ^ hit the nail on the head. Technically, you don't bridge the sub. Bridging is a method of wiring your subwoofer to a 2 or 4-channel amp by using the + of channel one and the - of channel two, taking the power from both channels to provide as much power as possible to the sub. However, you do have to be careful when bridging. Impedance drop can be dangerous for an amp, but you can usually get away with it the first time around because (most) amps have 4-way protection circuits. If it shuts down once and is hot to the touch, the first thing you check is the impedance load your amplifier is "seeing". One of those protections is thermal, impedance drop will cause the amp to heat up and if it gets too hot, it will shut itself down to prevent damage.

    Also, Visonik's amplifiers are very, very overrated. You said the "400w RMS" amp has a 10A fuse on it. Here's a little trick to see how many watts an amp will actually push without even hooking it up. Take the total number of fuses when added together and multiply it by your operating voltage (in your case, it would be 10A x about 12.4V). That will give you 124, then you have to find out the efficiency of the amplifier itself and since I don't know which model of amp you have, we'll just say 84% efficient. Take 124 - 84% and you get 40w RMS. The formula is A (total amperes) x V (voltage) - E (efficiency) = W (RMS watts)

    Hope this helps!

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