help with settup subwoofer on vintage yamaha c-4 preamp for 2-channel stereo

[matthill75]

Happy Holidays Ya'll!

Got a few questions. I bought a subwoofer (cerwin vega xls15s) for my HT system (Emotiva umc-1 pre to emotiva xpa-5 power amp) for 5.1.

My 2-channel stereo system consists of a refurbished Yamaha C-4 preamp and Emotiva xpa-2 power amp. They trade the main speakers back and forth (Cerwin vega XLS-215) but are otherwise separate.

I was curious about hooker up the subwoofer to my 2-channel stereo system and have questions about setting it up.

The Yamaha has two pre-outs. Easy enough, right? One pair of RCA's too the power amp and one set to the powered subwoofer.

My question involves how to set up the crossover frequencies and volume control on the subwoofer itself.

The Yamaha has a main feature being "tone bypass" where you can get straight signal path from the source to speakers. Its a clean path and it bypasses all the bass/treble controls, turnover frequency controls, and low/hi filters. This is typically turned on.

If I add a subwoofer, do I need to turn the "tone bypass" off so I can tweak the turnover (crossover) frequency of the mains and turn the filters on/off?

In addition, If I turn off the "tone bypass" wont anything I do to change turnover frequencies of the main speakers also affect the signal going to my subwoofer?

I presume that an older preamplifier with two pre-outs was for running monoblocks and not for a powered subwoofer.

[markw]

Happy Holidays Ya'll!

Got a few questions. I bought a subwoofer (cerwin vega xls15s) for my HT system (Emotiva umc-1 pre to emotiva xpa-5 power amp) for 5.1.

My 2-channel stereo system consists of a refurbished Yamaha C-4 preamp and Emotiva xpa-2 power amp. They trade the main speakers back and forth (Cerwin vega XLS-215) but are otherwise separate.

I was curious about hooker up the subwoofer to my 2-channel stereo system and have questions about setting it up.

The Yamaha has two pre-outs. Easy enough, right? One pair of RCA's too the power amp and one set to the powered subwoofer.

My question involves how to set up the crossover frequencies and volume control on the subwoofer itself.

The Yamaha has a main feature being "tone bypass" where you can get straight signal path from the source to speakers. Its a clean path and it bypasses all the bass/treble controls, turnover frequency controls, and low/hi filters. This is typically turned on.

If I add a subwoofer, do I need to turn the "tone bypass" off so I can tweak the turnover (crossover) frequency of the mains and turn the filters on/off?

In addition, If I turn off the "tone bypass" wont anything I do to change turnover frequencies of the main speakers also affect the signal going to my subwoofer?

I presume that an older preamplifier with two pre-outs was for running monoblocks and not for a powered subwoofer.

First off, assuming you'll be connecting the subwoofer between the pre-amp and the power amp, it will be in the circuit at all times regardless of how you have the controls on the preamp set. The subwoofer comes after the preamp. Anything you do on the preamp will be felt in the subwoofer.

Please note the bolded section above. It's not quite true. You might want to think of it thus: "The Yamaha has a main feature being "tone bypass" where you can get straight signal path from the source to the output of the preamp".

Given my druthers, i'd have as few tone controls in te circuit when setting up the subwoofer.

Depending on what the subwoofer can do and what your speakers can do, you can run the subwoofer in parallel with your power amp and set it's low-pass filter to simply take over where your mains start to drop off. It may take some time to find te perfect crossover frequency and level but it can be done. HAve patience. Also, play wit room placement. Subs can be fairly picky here so experimentation is recommended.

Some, not all, subs allow you to connect the sub "in series" with the pre/main and will filter out the lows that your main amp handles.

Persoanlly, i like to run my mains full range use the former scenario.