Magnepan 1.7 and Subwoofer help/recommendations


I seem to have gotten myself into a bind with purchasing a subwoofer. Hear me out. I recently acquired myself a pair of Magnepan 1.7s, and they sound great. The problem is at about 90hz, the speakers completely fall apart. Obviously, it's practically incapable of producing frequencies below 30hz, which is fine with me, but my problem is that at about 50-80hz, it's a got a big honking hump of bass that overpowers a lot of the details in the mids and highs. It's like they know that they're about to give out, so they give one last big push. I would honestly rather have less bass in that area, which is what leads into my subwoofer problem.

I use my Benchmark DAC1 USB as a preamp, using the XLR outs going to my Bryston 4B with only XLR/TRS inputs. After having read some suggestions on subs that match well with Maggies, I made a list. Practically the #1 suggestion I saw was Vandersteen 2wq. I saw one online yesterday used for a good price, and I called Vandersteen, and they said that in order for me to set it up, I would need to purchase the M5 crossover, which would cost quite a bit of money ($600 minimum), which I would rather not spend. On top of that, there is only 1 Vandersteen dealer that I know of in Canada, and they haven't called me back as to whether or not they have the M5.

After looking online at a bunch of options, I've gathered that all of them pretty much only have RCA ins and outs. So, my question is: Where can I find a subwoofer that will a)match well the Magnepans
b)I can hook given the limitations of my system
c)Under $800 used
d)Goes all the way down to 20hz (Kind of just a bonus, not really necessary)

Presumably someone here would know more about this. If you do, please help me out and offer some advice. Thanks in advance for any responses.
ninjasquirt
I'll second Kjweisner's recommendation for the Vandersteen 2wq.

I have a pair of them to back up my Magnepan 3.7 speakers, and consider it a great addition. Even though my amp is more than powerful enough to drive the Maggies, rolling off the bass to the 2wq's relieves some of the load from the amp; it was immediately noticeable.
Ditto 3rd
The beauty of this is you can adjust the 2WQs high pass "in your case tighten up the Magnepan's bass" and adjust the Vandersteen 2WQ's controls for your rooms best in room response.
The assessment box that comes with all 2WQs allows one to experiment for best performance and later order the fixed affordable 140 dollar version.
The advantage here is you pre amp is going through a quality Hi pass compared to other types going through a 50 Cent integrated circuit or just adding blubber bass and clouding up the in room response.
JohnnyR
Vandersteen/Magnepan/dealer
And I'm in support of what Audioconnection says, above.

I started right away with the variable crossover. It adds to the expense, but I'm glad I did it as it allows you to play around with the settings to find the best result.

I started with the crossover at the input impedance of my amp. Sounded good. After settling in, I used one setting up, and then one setting down. The down (I think) really made a difference.

Once you get that where you want it, close up the boxes and work the dials on the back of the 2wq. If you want "bloomy" bass, you turn up the Q factor dial. Using a second dial, you can determine what frequency to roll off the bass. I'm still playing with that one, based on my tastes from day to day.
One common trait planars share with conventional box speakers in regards to bass is size...and size matters...anything smaller than 1.5,1.6 1.7 is bass compromised... That is the bass presented lacks depth and scale... This is their signature sound...and no amount of power will change that...however...surface area will. My Maggie dealer carries REL subs.
Unless you are looking for really deep bass, I would like to suggest that you try using Dirac Audio Processor or similar DSP software. I have Magnepan 1.7s driven by a Linn amplifier (100 w/ch @ 4 ohms). Without using Dirac, I have a 5dB peak at 75 hz and a 5 dB drop out at 150 hz and 250hz. Both of these distortions are well corrected by the Dirac Audio Processor. The processor allows you to tune the speakers to fit your taste (while still respecting the physical limitations of the speakers). I bump up the bass about 2dB and roll it off starting at about 55 Hz. This provides a very satisfying sound for classical and jazz recordings. Violas, cellos, and string bass all sound very full and natural. Dirac also mellows some of the glare in the upper treble of violins. Dirac provides a 14 day free trial. All you need to try it is a calibrated microphone.