Adding a Sub in a power amp direct DAC configuration.

[AudioExplorations]

I guess subs are usually added to a system through use of the secondary outputs on a preamp where they would benefit from their own dedicated output stage driving the input stage of the subwoofer amplification.

What are the options sans-preamp? My weiss medea DAC has two sets of outputs (XLR and RCA), would I be able to hook up the sub in this manner? The output stage is extremely robust with a near 0 ohm impedance. Issues I foresee are the fact that still a single output stage would be driving both the speaker and sub amp input stages, and the fact that the RCA outputs are 6dB quieter than the XLR (I may be able to compensate this with an adjustable active sub).

Also, my wavelength cosecant DAC has a single set of RCA outputs and a somewhat higher output impedance (600 ohm), would I be able to use some sort of adapter to connect both amps or would this likely overly stress the cosecant output stage?

Would I be best of to introduce a preamp into the system if I wanted to add the subwoofer?

Appreciate any feedback I can get.

[Julf]

As long as the output impedance of your DAC outputs is significantly lower than the input impedance of your amp and sub, it should work nicely.

[wgscott]

Why not use speaker-level input (if you can)?

[AudioExplorations]

You mean a passive sub hooked up to the single power amp?

[wgscott]

No

I mean an active sub hooked up from the speaker terminals on your amp (or speakers), and to the speaker-level input on the sub (assuming your sub has one -- many do, like Rel, Velodyne, etc).

[AudioExplorations]

Just looked it up, was not aware of level input. I guess that's definitely an option however I have read mixed reviews during my brief research, apparently line level out to the sub is still the cleanest way to go.

[wgscott]

I've seen some fairly compelling arguments to the contrary, for example from Jim Smith (Get Better Sound and posts here).

[wgscott]

I've seen some fairly compelling arguments to the contrary, for example from Jim Smith (Get Better Sound and posts here).

cf: http://www.computeraudiophile.com/content/Classical-music-2-channel-and-sub-woofers

[AudioExplorations]

Good stuff, thanks for the link.

Am hoping your right cause it would mean problem=solved

[TechHiFi]

I also do not have a pre-amp. I hooked up my PSB subs using the RCA outs from my W4S DAC with the XLRs to the main amp. Works great! W4S prefered this method. I would ask Weiss. I have not tried using the speaker cable hook-ups.

[AudioExplorations]

From what I have read the speaker cable hookups are the preferred method because the system's sound signature is carried over to the sub and hence results in better integration in the system.

Good to hear that line out direct from your W4S dac is also an option, I am sure I will be fine running it this way with either of my DAC's.

I will likely go for a REL sub and run speaker level.

[crisnee]

An advantage to using the line out/in option with powered subs is that you can run your sub(s) with an EQ unit while not affecting your basic amp/speaker setup.

To get the best sound in my room I needed to add a parametric eq because I could not sufficiently tame a room mode, not to mention that I could adjust the bass curve to a t. The EQ made a very big difference in the SQ of my system.

-Chris

[AudioExplorations]

The disadvantage here is that you add an additional element in the chain.

I plan to flatten out the response the way I do currently with my full range speakers; room measurement with REW, creation of filters within REW, application of filters using Fabfilter ProQ as a VST within Pure Music. To my ears 100% transparent and no hardware required.

[Sumflow]

On the McIntosh are U shaped Jumpers that go from the pre amp output, into the power amp input. Just replace the U jumpers, with Y jumpers, and put the active sub woofer's two RCA's on the third legs.