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BrianG · 01:12 PM

PartsExpress is where I shop at for fairly inexpensive DIY parts. You might find cheaper stuff elsewhere so shop around. For plate amps, this is what they have.

Looks like the 240w version is about the max you'll get for a relatively low price of $100. It gets expensive for more power than that, and they don't have speaker in/out terminals. And usually, if the amp has speaker in/out terminals, it includes a crossover to limit the low frequencies to your main speakers. The 240w version is the output rating at 4 ohms. If using an 8 ohm sub, it's 170w. So impedance does play a role here, which is why it's important to know what you plan to run on the amp.

In case your sub is dual voice coil:
- If each coil is 2 ohms, hook them in series for 4 ohms total
- If each coil is 4 ohms, hook them in series for 8 ohms total. Hooking them in parallel gets you 2 ohms and that's too low for most amps and the amp would be unstable.
- If each coil is 8 ohms, hook them in parallel for 4 ohms total.

Hookup of a plate amp is as simple as cutting out an opening in your sub box, hooking up the sub's wires, screwing the plate into the hole, and hooking to 120v and to your system. If your receiver has sub RCA outputs, use those. If not, route your main speaker wire to the sub speaker inputs and then to your speakers.

And about the phasing issue: Yes, it can make a difference, but he's not running high end stuff to make a difference. Usually, simply using the phase reverse switch on the sub amp to adjust to 0* or 180* is adequate. Ideally, you'd want all your speakers to be mounted on the same vertical plane for proper phasing, but then your sub response might not be the best in that location. Higher-end sub amps have adjustable phase control for this, but those are more expensive and I'm sure cost is an issue here.

	(#45)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	02.27.2008, 01:10 PM PartsExpress is where I shop at for fairly inexpensive DIY parts. You might find cheaper stuff elsewhere so shop around. For plate amps, this is what they have. Looks like the 240w version is about the max you'll get for a relatively low price of $100. It gets expensive for more power than that, and they don't have speaker in/out terminals. And usually, if the amp has speaker in/out terminals, it includes a crossover to limit the low frequencies to your main speakers. The 240w version is the output rating at 4 ohms. If using an 8 ohm sub, it's 170w. So impedance does play a role here, which is why it's important to know what you plan to run on the amp. In case your sub is dual voice coil: - If each coil is 2 ohms, hook them in series for 4 ohms total - If each coil is 4 ohms, hook them in series for 8 ohms total. Hooking them in parallel gets you 2 ohms and that's too low for most amps and the amp would be unstable. - If each coil is 8 ohms, hook them in parallel for 4 ohms total. Hookup of a plate amp is as simple as cutting out an opening in your sub box, hooking up the sub's wires, screwing the plate into the hole, and hooking to 120v and to your system. If your receiver has sub RCA outputs, use those. If not, route your main speaker wire to the sub speaker inputs and then to your speakers. And about the phasing issue: Yes, it can make a difference, but he's not running high end stuff to make a difference. Usually, simply using the phase reverse switch on the sub amp to adjust to 0* or 180* is adequate. Ideally, you'd want all your speakers to be mounted on the same vertical plane for proper phasing, but then your sub response might not be the best in that location. Higher-end sub amps have adjustable phase control for this, but those are more expensive and I'm sure cost is an issue here. Last edited by BrianG; 02.27.2008 at 01:12 PM.