help choosing musical sub for minimonitors [Archive] - Audio & Video Forums


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04-18-2006, 12:20 AM
just picked up a pair of B&W CM1's

never had a stand mounted speaker before and woould like
a fast musical sealed sub to give me a little extra bass
also i would like to reduce the stress on the cm1's so that they
dont have to produce the lowest frequencies so they can concentrate
on the midrange up

my problem is i did not like the B&W sub offerings i heard
i have to drive quite far to hear a rel sub mated with the cm1's
and i won't have time to do that for a few weeks

i am not really a newbie but i have never had a sub hooked up
to my system nor have i ever had an av receiver

my system consists of an amp and a preamp

from what i read i think i need a sub with high pass and low
pass connections to provide the lowest frequencies and to relieve
my minimonitors from low bass and midbass duty?? am i right ??

how would i hook this type of sub up tp my preamp as i only
have one set of unbalanced connections
although i do have a tape monitor connection if that helps
but no subwoofer out or bass managemant capabilities or even
tone controls on my preamp
i only have one set of left and right outputs on my amp also

can this be done effectively?????

thanks for any help or suggestions

04-19-2006, 12:33 PM
I use and recommend Def Techs Pro sub 100. Excellent choice for music without breaking the bank.

04-19-2006, 01:41 PM
Well, hopefully someone will chime in about your preamp concern. I know many subs offer inline crossover via speaker cables, but hopefully there is a better way.

In regards to subwoofers, value minded I like the HSU VTF-3 MK2, $700 new.

I have the smaller one, VTF-2 MK2, but recommend the big brother if you can afford the difference. Bass is clean, fast, and flat. In my case my room is the weakest link. But HSU is very helpful in room placement and suggestions. I was able to email a picture of my room with dimensions and HSU made a few recommendations for placement. Also, "crawling for bass" in the How To section is helpful.

How big is your room?

04-19-2006, 09:23 PM
In your situation, you'll need a subwoofer that has a high pass crossover in order to filter out the low frequency content that gets sent to the speakers. You can connect the preamp directly to the subwoofer crossover, and connect the high pass outputs to your amp. Or you can use the tape monitor position like you would with an equalizer. Unfortunately, most active subwoofers out there assume that you use a system with some kind of subwoofer output and bass management, so the internal crossovers will only do a transparent pass-through for the line level inputs that keeps the low frequency content intact.

Fortunately though, the simple remedy to this is to connect the line level output from your preamp to an external bass management device like the Outlaw ICBM, or the Paradigm X-30. This will filter out the low frequency content that goes to your amp, while sending the low frequencies to the subwoofer. But, the necessity of an external bass management box will depend on whether the line level high pass filtering can be done by the subwoofer.

Regardless of whether a high pass filter is included, there are plenty of sealed subwoofer options now out there. You've already ruled out the B&Ws, which are sealed but from what I understand the response curve is more optimized for home theater sources. Other sealed options out there include mail order subs from Acoustic Visions, Rocket, ACI, and the Dayton DIY kits, while retail options include B&W, Paradigm (the Servo-15), Atlantic Technology, Sunfire, Velodyne (their Digital Drive models), and Martin Logan.

Adire Audio used to make a sealed sub with fully variable high pass filtering (the Rava SE), unfortunately that model was discontinued when the plate amp used in that sub went out of production. And more recently, Adire has taken a very long time to reintroduce the new version of the Rava, which was a very competitively priced sealed sub in its original incarnation (which I own). Not sure when or if it's going to come out, otherwise it would have been another option worth looking into.

You might want to give Acoustic Visions a call and let them know that you want something for a two-channel application. They sell their own prefinished subs, and subwoofer drivers and amps from outside vendors; and they can piece together a DIY kit for you or custom build something for you to your specs. You can specify an amp with a high pass filter, pick out a driver, and Acoustic Visions makes several different sized cabinets that be matched to the performance parameters that you want.