Best Subwoofer Connection for Music

I have struggled to integrate subwoofers into my two channel systems in a way that enhances the system’s musicality. The best system so far is an old, cheap, dual coil subwoofer, but it has limited capability. I have two subs I want to add, one each, to each of my current systems. (Profile still under construction, which I’ll detail below.) I’ve heard PS Audio’s recommendation of the use of high level connections for music (versus low level connection for Home Theater LFE [Low Frequency Effects]), and I caught a comment on one audio YouTube post to be sure your subwoofer had both hi-level IN and Hi-Level OUT. This, to me, means that the subwoofer connection for music being recommended is Amp [Left & Right] —> Subwoofer Input [Left + Right] —> Subwoofer Output [Left & Right, again] —> Main Speakers [Left & Right]. Is this right? Just like the old dual coil subwoofer, but this time, the Subwoofer plate amp is adding Left + Right.

One Sub has both low level and high level inputs [an 90’s RCA 10” 100 Watt unit marketed by RadioShack. The other Sub, 15” 250 Watt from Dayton Audio, has three different options for audio I/O, to include two sets of low level I/O: (1) RCA and Speak-On connectors for low level input, and (2) RCA and XLRs for low level output. Meanwhile, it also has (3) high level spring clip speaker connectors for both input and output.

(1) I would like to integrate the smaller sub into my tube setup which consists of a Rogue Audio RP-9 + Rogue Audio ST-100 Dark 100 wpc feeding a full-range vintage acoustic suspension Warfedale W70E 3-Way which features a wonderful 15” driver, that I sometimes wish had a bit more ‘punch. (2) I would like to integrate the larger sub into my solid state system which features a McIntosh C100 preamp [I’m still learing how to parse McIntosh model numbers] which allows one to connect to three separate amps [Main (unswitched) + Speaker 1 & Speaker 2 (switched)] currently feeding dual McIntosh MC252 power amps bridged to mono, powering 90’s era full range B&W 801M Series 2 speakers with front ports and upgraded crossovers. The B&W speakers could benefit, I feel, from the ‘wrap around’ room-filling bass sound a 15” driver can provide.

The Dayton plate amp is the most recent addition, and if I need to upgrade the plate amp in the old RCA sub, I’m open to that, maybe by Christmas. [I had forgotten it had only ‘one-way’ connections.]

I’m mostly concerned with what connections would allow me most effectively integrate each sub into my two ‘music only’ systems. Thanks for any help you can offer.


@erik_squires Agreed. It is not the best way to connect a subwoofer and I’m sorry I brought it up. 

Where are your subwoofer cabinets positioned within your room and how were those locations determined?

There really is only one correct way to add a subwoofer: insert a high pass/low pass electronic crossover between your preamp output and the inputs to the main speaker amp(s) and the subwoofer amp(s). Anything else is just an attempt to get a subwoofer operational without the benefits of true bi-amping.

@m-db I haven’t gotten that far yet on this go-round. In the past, I’ve placed the sub in the listening position and gone around the room to find the spot the bass was strongest. The Dayton-Amped 15” sub for the McIntosh system is headed for the #1 ‘sweet spot’ in the right front corner; the 10” RCA sub with the Rogue system will go to sweet spot #2 in the left front corner initially. The Sound Doctor (see ditusa’s link on first post) suggests that placing a second sub in the back of the room may be desirable. I’m just trying to get one per system up and running (correctly) before experimenting with a second sub. And I would likely try that in the upstairs listening space first. Good question, though. 

@panzrwagn The experts agree with you, see ditusa’s link in first response post above. I have a capable active crossover that I’m itching to use, a vintage Pioneer D23, so I have what I need to implement your (and the expert’s) recommendation. I’m going to try it without the crossover, and then with it. I’ll let you know how it works out. 

All: To anyone stumbling on this thread, Panzrwagn’s pronouncement is, indeed, the best way to connect a sub: using low-level connections, optimally downstream of the best active crossover attainable; although there are many options short of that that are all an improvement. As I’ve noted several times above, ditusa, in his first response to my post links to a rather complete treatise on the topic by the Sound Doctor (his name is given in the link) who has worked in field for over 15 years [probably 20 years now] and spent enough time with JL Audio to develop the finest crossover for the purpose in the industry (according to him). I found his writing style quite approachable. He recognizes that integrating a sun is NOT an easy task, but he explains WHY it isn’t easy and what can be done about it. If you’re interested in the topic of this thread, I recommend highly reading it entirely.