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Subwoofer Options With No Spare Preout

I only have one preout on my preamp, and I’d like to add a pair of subs to my system. I’m curious peoples thoughts on the best method. I have a few options in mind that I’d like feedback on but if I’m missing an option let me know.  First option I’m considering is a pair or Rel’s which would be pretty straightforward to setup. I’ve also thought about getting a separate crossover with both high and low pass filters. I know in theory this is likely the best solution. I won’t be working with a large budget so something like a Sublime Acoustic K231 is probably the best I could manage. The likes of JL audio, Bryston, and Marchand are bit out of budget.  This would allow me to use any subs I’d like, possibly even some DIY passives. The last option I’m considering is simply splitting the one preout and running one channel to each sub. I know it’s not ideal but I do have considerable excess gain in my setup even though my pre only has 9db. I never get past 10 o’clock but generally at high volume I’m around 9 o’clock. 
 

My system right now consists of Audio Mirror Reflection monoblocks, a Canary C630 pre, Totem Arros, and a Bluesound Node.  The room is 9ft by 11ft with 8 foot ceilings. I’m still uncertain if my next purchase will be subs or a new digital front end. Both will happen before to long because I need more bass and I know the Node is holding back my system considerably.  Anyways any thoughts or opinions are much appreciated. 

brylandgoodman

Showing 4 responses by erik_squires

erik_squires
15,803 posts
 

That website is a rambling mix of useful information and total BS I’m afraid.

 

Subs have significant output into the mids

BS. Not if properly configured. Most use a 4th order low pass filter and usually don’t go any higher than ~ 120 to 150 Hz.

and are localizable.

If you mean you can hear where they are there are only two reasons I know of only two reasons for this:

  1. External vibration/rattling
  2. Too high a crossover point.

In my system not only can you not localize the sub but you can’t even really tell it’s working until it is off.

Therefore they must be coherent with the mains.

No, eliminating localization and making sure your stereo output presents one coherent presentation are not exactly the same thing.

The easiest way to achieve this is to have them in the same area as the mains.

A - Not true and B - I wish it was that easy.

erik_squires
15,803 posts
 

Oh, the Duelund JDM-Cu are a steal at around $30 each from Parts Connexion.

erik_squires
15,803 posts
 

Hi OP:

The cap provides a first order high pass filter. You want to use a cap which provides the same impedance as your amp’s input impedance. So if the amp is 47k your cap should also be 47k at the crossover point, which I recommend no lower than 80 Hz. With those low efficiency speakers this will greatly reduce distortion and make your amp play much louder.

I believe this just happens to be 0.047 uF for you. I recommend Jupiter copper foils.

This simplifies subwoofer integration, and will double the apparent size of your amps. Also, most people report greatly improved soundstage and reduced distortion this way.

PS - There is a myth audiophiles have that they should buy a subwoofer only for 1 octave.  Every single time I've convinced those audiophiles to try the alternative they never go back, not just for the bass but for the overall improvement in detail, soundstage, and dynamic range.

erik_squires
15,803 posts
 

Y adapter from preamp.  Single cap in series with amps.

 

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