Best way to add and cross-over dual subs in a 2-channel system?

[2FlyingYorkies]

This post could go in any one of several sub-forums, but I'm going to put it here as being multi-subject, and therefore "general". (mods, feel free to move)

I'm looking to add a pair of subs to my dedicated 2-channel system listed in my signature. I can see a couple of ways of doing this, and am curious how the rest of you have done it. A few options that came to mind:

1) Add the subs using the 2nd output on my preamp, use the sub's internal low-pass and let the Sopras continue to run full range;
2) Add some sort of active crossover between the pre- and power-amps (suggestions for which crossover?);
3) Migrate to a completely new front end (combined dac/pre?) with built in bass management and potentially room correction (suggestions?)

The goal is to fill in the last octave below where the Sopras start to run out of oomph (16-35hz, though I'd consider stretching it up to 60hz with the right subs and equipment). Big open-concept irregularly shaped multi-use living space that sounds surprisingly good as-is despite being an on-paper disaster for good audio. Budget depends on the complexity of the solution, but let's call it up to $10k plus the subs themselves.

I see pros and cons to all three paths, hence seeking the collective wisdom of the group...

Oh, and if anyone has a favorite sub (or stereo pair) that would visually and acoustically match my gloss carrara white Sopras, even better.

 

[Darrel]

I've found the sub out from my preamp to be the easiest when I had my two SVS 2000 Pros hooked up to my system. SVS have a app that uses bluetooth to connect and control phase, crossover and volume if you choose not to use the controls on the back of the subs. If you only have one sub out from your preamp a splitter can be used to feed each sub. Dual sub outs often allow for a stereo low frequency sent to each sub. That is what I used from my Gryphon Diablo 300.

PS, the two SVS 2000 pros are boxed up and sitting in my garage waiting for me to decide what to do with. If your interested in the SVS line drop me a message. Good luck

 

[Mr Peabody]

Most people let the mains roll off naturally and cross the sub at the point where it best blends with the mains.

REL allows connection to the speaker terminals. That was their preferred method. As mentioned already many use the second preamp out which is fine.

If you did want to look at a preamp Anthem makes a stereo preamp with bass management and DSP.

 

[crwilli]

I would go with option 1. Let your mains roll off naturally then use the flexibility of your two subs placement to smooth out the lowest end from there.

If your mains have a ‘suck out’ because of their room placement, your sub placement may be able to ameliorate that. Experimentation is key.

I have tried an external crossover before. The MEN220 from McIntosh and the JL Audio crossover. Both had their pluses but also added artifacts. I found your option 1 to be the best.

Good luck.

 

[W9TR]

When you add subs you become a speaker designer, even if you didn’t want to be one.

Sub placement with respect to room boundaries and the mains will have more of an impact on the final result than how you choose to integrate the subs.

For my HT, I use dedicated bass management and time alignment to account for the 1 mSec delay in the subs due to their internal DSP processing.

For 2 channel all that goes away and I just run my mains full range.

I would try the pre-out route as that is usually the easiest.

 

[nicoff]

Most preamps have two speaker outputs (one balance output and one RCA output).
Option 1 (no external equipment)
Run one of those outputs to your main speakers. Run the other to the first sub.
Many subs allow you to run one of them as a master and the other as a slave. So you would connect the output from your preamp to the master sub. Then run a cable from the master sub to the slave sub.
You can then use the internal filters in the master sub to control the crossover.
Important: the location of the subs is actually more important than the crossover frequency. You can google and learn about different ways to find the best location for the subs. It will depend on your room.

Option 2 (with external crossover)
You could use a MiniDSP device. More information here: https://www.minidsp.com/applications/digital-crossovers/194-subwoofer-integration-with-minidsp

Option 3.
Adding Room correction (DSP) is a completely different subject. DSP can be added to the two options above. There many threads on this subject in ASR.

Note: If you stream your music, there are several streamers (like WiiM Pro and others) that allow you to add DSP to any system without the need for special equipment or software.