Subwoofer Hookup Question

[N1ESE]

Newbie question #545923

Let's say I have your typical 2-channel tube SET amplifier and a pair of small nearfield monitors that are lacking in the bass department. How would I go about adding a subwoofer to a configuration like this? I presume I would need to split off the subwoofer signal somehow before the SET or can I XO this after?

Thanks

- JT

[Cal Weldon]

Hi JT,

Buy a plate amp to go with the woofer. It has speaker level inputs that include an XO for the speaker level outs for your satellites. About the same price as buying the components for a 24 dB passive XO.

[GM]

Easiest thing to do is to either use 'stereo' 'subs' digitally XO'd at <120 Hz and wired in parallel with the mains or a single dual voice coil (DVC) sub driver with each VC digitally XO'd at <120 Hz and wired in parallel with the mains.

The problem though is that SETs typically don't have enough power to do this except at low average SPL, so making a separate 'sub' system driven by a separate SS or at least a higher power PP tube amp is the best way to go, though the latter typically needs a large box and high efficiency (HE) drivers. Of course for this you need to split off the signals ahead of the amp.

Note that ideally you want the 'sub' system to be up to 6 dB more efficient (though 3-4 dB is the most often measured of those posted) than the mains for baffle step loss compensation (BSC) if not corner loaded. That, or a system that can handle up to 4x the power (Pe spec) and linear excursion (Xmax spec) of a similar efficiency to the mains at low distortion (< half the driver's rated PE).

GM

[N1ESE]

Thanks for the input guys. I appreciate it.

- JT