Connecting Sub to standard amp.......?

[Uzey]

My dad has just purchased a cheap Yamaha 5.1 speaker set from Richers to rig up to his old 'Dolby Pro-Logic' Kenwood amp (a bedroom set-up). The problem is that the amp has no 'subwoofer' output and the speakers really need the sub to provide the bass.
Is there anyplace I can purchase a 'cross-over' which allows me to connect both front/left and front/right channels 'into' it, splits the lower frequencies to a 'subwoofer' output, and then has left and right outputs so the stereo signal can carry on to the front speakers?
The sub has 'left (mono)' and 'right' phono sockets.

Thanks on advance.

Scott.

 

[The Hemulen]

does the sub have any form of variable or fixed low pass filtering on the back panel?

 

[Ian J]

Does the sub not have high level connectors to enable it to be connected to the amp's speaker connectors.

 

[Uzey]

Nah! It's just a cheapo sub with an auto switch (to switch it into standby if no activity is present), a volume control and two phono connectors (Left and Right with the Left one labelled 'mono').

 

[Ian J]

I think that you are out of luck. If the amp has no low level output and the sub has no high level connector the twain will never meet.

Looking on the bright side, AV amps have improved a lot since the old Pro Logic days so perhaps it's time to upgrade

 

[The Hemulen]

Got to agree with Ian here. If the sub had some sort of low pass filter then it would be pretty easy to knock up a resistive network to sum the speaker outputs and attenuate to a suitable level for the line input.
Actually it wouldn't be that hard to do the low pass filtering as well but it's probably not worth it in this situation. Much better to keep an eye out for a bargain 5.1 amp on here or in Richer Sounds.

 

[Uzey]

Aw shucks!
Thanks anyway!

(now, where did I put that Richer Sounds catalogue?)