Subwoofers and Merlins

A sub works well with the VSM-MX. I'm using a Vel DD-15 with LPF set at 30Hz & 12db/octave slope. Avoid any recent DD models with 2.2 software; 2.2 precludes crossover settings below 40Hz.

When using the BBAM you need preamp line-level inputs to the sub, as the BBAM rolls off all bass content below 28Hz. For seamless midrange to bass response it's best to keep the BBAM in the circuit and use a low & unobtrusive crossover point.

I've improved the Vel with a rectifier upgrade and silver internal wiring. If I were buying new today I would try the JS Audio Fathom.

Thanks gentleman for the responses. Dgarretson, could you explain a bit more to me about the set-up of integrating the BBAM with the subwoofer and how to determine setting the LPF a 30hz with a 12db/octave slope?

Are you setting it there because of room acoustics and proper integration? Is there other reasons?

As you can see, I am new to this subject of a subwoofer but most intrigued, so any help would be appreciated!

Tmiddle, beauty of a system by the way. I bet it sounds fantastic. How is it intergrating a sub with your room placement? What struggles did you come up against and how did you work with those?

Thanks

Maria, in my benign room at least, without the sub in the configuration the VSM-MX with BBAM is flat +/- 3db down into the mid 30's, after which response tapers quickly to the point that below 25Hz there is no useful LF. Setting sub xover at 30Hz and 12db/octave slope adds fill up into the mid-30's and foundation & impact from 17Hz-30Hz. Even with this low xover and a fairly steep slope, the sub's digital EQ can tilt up bass response to fill voids in the 35Hz-45Hz range owing to room effects. But in general bringing the sub back in at higher frequencies than 40Hz just muddies the sound. With this speaker you want to bring the sub in low and get it out of the way with a steep slope above the crossover point.

Nice thing about some modern subs is the integrated frequency analyzer that visualizes response with and without the sub. But IMO, while satisfying an unmodified Vel DD is not the last word in tight bass control.

Very well put. Thanks.

JL Audio fathom. What do like about that sub? One of the things that impressed me about the Vel DD was it's supposed ease of set up. Do you not think it is an ideal setup with the Merlins because of the crossover limitations at 40Hz? Can you explain crossover to me more precisely?

How does the JL Fathom compare to you in this realm?