Adding a sub?

kwarren122

Im adding a little sub to my system and my adcom preamp doesn't have a sub-out line, so Im wondering which is the best way to do it.
I can use the speaker cable deal or split the rca's on the output of the preamp, is one way better than the other?
Thanx in advance

rooftop59

What speakers, what model amp, what subwoofer, and do you want to use te subs high pass filter (if it has one) to block some low frequencies from going to the speakers, or run the speakers full range?

Rich502

Does your adcom preamp have dual preamp outputs? Some have normal and bypass outputs. That could be an option to use the bypass set for the sub.

kwarren122

Yes it does and thats what I used, but ended up getting rid of the sub because I changed my amp to a GFA555 and it really woke up my SDA 1's

PSOVLSK

This could possibly be a record for amount of time between posts, but I'll glad you followed up on this thread. From my limited experience with SDA's I'd say a sub in unnecessary. Glad you're getting great sound now. Enjoy!

nooshinjohn

Look at REL Subs. They use a high level signal to run the sub, drawing signal from the left and right positive leads from your amp, and become nearly invisible...

http://forum.polkaudio.com/discussion/178971/new-rel-s-5-in-the-house#latest

F1nut

There are a number of sub companies such as Velodyne that recommend using high level inputs for the best musical integration. In fact, I can remember Polk recommending that method 15 years ago.

BlueBirdMusic

I received this in Paul's daily email a few days ago:

The best way to connect a sub

We touched briefly on subwoofers and speaker setup in yesterday’s post. What I didn’t cover is how best to connect a subwoofer if you choose to go the extra mile and complete your system.

Years ago, there were mostly passive subs, but over time this changed. Modern subwoofers are internally amplified. So it might seem intuitive to connect them as you would any power amplifier, with an interconnect to the preamp or DAC. This works, but would not be my first choice.

The problem with cables and subwoofers is two-fold: double-long interconnects and a missed opportunity and synergy.

Preamplifiers aren’t especially appreciative of the cables that connect them to amplifiers. Shorter is better if you can manage. Worse is when you double up the cables: one to the loudspeaker amplifier, the other to the subwoofer amp. A much cleaner, better sounding way of doing this is with the use of a Y connector at the amp. In this scenario, you have one cable between the preamp and amplifier (with a Y connector at the amp’s input). A short interconnect from the Y connector to the subwoofer completes the circuit. This relaxes the load on the preamp relative to running two parallel interconnect feeds.

My favorite method is to tap the output of the loudspeaker power amplifier instead. Some subwoofers have a high-level input that can accept the main power amp’s speaker outputs. (Check to make sure this feature is available before purchasing a subwoofer) In this configuration, the amp’s power is not being used by the subwoofer, just its signal. Internal to the subwoofer are high-value resistors that neck-down the amp’s big output to something usable to the sub’s internal amplifier.

The advantage of using the second method is maintaining the sound quality of the power amplifier. As we know, each power amplifier has its own sonic signature. If you use the amp’s output to feed the sub amp, you maintain sonic consistency and improve system synergy.

Remember, the goal of a subwoofer is to extend the low-frequency response of the main loudspeakers. We don’t want to hear the subwoofer. We only want to make believe our main speakers have low-frequency extension (which most do not).

If you’d like to learn more on this subject, WATCH THIS VIDEO I prepared for you.
http://www.psaudio.com/askpaul/are-special-cables-required-for-subwoofers/