QuestionQUESTION: Hey Brian, i have got a question about an amp. It is a new phoenix gold 1600 watt amp that has a frequency response that ranges from 10-400 hz. It has speaker level inputs. So, does the amp only send power to the rear speakers that produce frequencies that range from 10-400 hz? Also, how would you install the amp to run a single sub and the speakers through the speaker level inputs. Sorry for all the questions, but I don't know a whole lot about this kind of stuff. Thanks in advance.
ANSWER: Bryce,
Sounds like it's a mono amp. Many mono amplifiers are only meant to work with subwoofers. That's the reason for the limited frequency range: it's just a bass amplifier. You won't be able to use it for your rear speakers and subwoofer together, unless you only want your rear speakers to play bass. Even then, it probably wouldn't be a good idea.
It sounds like you're confused about the function of the speaker level inputs. Speaker-level inputs (also called high-level inputs) are used when you're connecting the amplifier to a factory radio. They're an alternative to using RCA cables to get the sound into the amp. Factory radios don't usually have RCA pre-outs, so the high-level inputs let you connect the amp to the factory speaker wires. They're a way to get sound into the amp, not a way to get power out of the amp.
If you want to use a single amplifier for your rear speakers and your sub, the best option is a multi-channel amplifier. If you had a 4-channel amp, you could use two channels for the rear speakers, and "bridge" the other two channels into a single channel for the subwoofer. This only works if you have a single 4-ohm subwoofer, however.
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QUESTION: So, how would you wire a 4-channel amp to wire the sub and the speakers at the same time?
AnswerIt works best if your CD player has separate RCA outputs for the rear speakers and the subwoofer.
Connect the "rear" RCA cables to the channel 1 and 2 inputs at the amp. Connect the "sub" RCA cables to the channel 3 and 4 inputs.
Connect the left rear speaker to the channel 1 speaker output, and the right rear speaker to the channel 2 output.
Connect the subwoofer to the channel 3 and 4 speaker outputs in a "bridged" configuration. Typically it means connecting the sub's positive terminal to the channel 3 positive output, and the negative terminal to the channel 4 negative output.
This type of setup is commonly called "3-channel", and any multi-channel amplifier should have a diagram for it in the owner's manual.
If you did this with a 4-channel, 75 watt-per-channel amplifier, you'd end up with each rear speaker getting 75 watts and the subwoofer getting between 200 and 300 watts.
Again, this only works well with a single, 4-ohm subwoofer.
