Subwoofer Question s

Being VERY mechanically challenged I need help.

Is there a subwoofer available that can be hooked up to a preamp which will automatically cut off base to my speakers without bypassing the excellent crossover in my speakers?

Or some other way I can accomplish this?
When you add a subwoofer it effectively adds a low pass filter in addition to you speakers crossover. The quality of the sub will depend on how much it will affect your sound when connected. JL audio E112 has a built in digital crossover designed to connect between the preamp and amp.
Schubert - Only yesterday, I picked up my second Vandersteen 2wq subwoofer. I love what they do for my system (digital source, PS Audio PWD MKII DAC/pre, Spectron Musician III amp, Magnepan 3.7 speakers.)

Although the subs come with small crossovers so that you can dial in the right sound, the real fun comes in with Vandersteen's battery-biased crossover. These go between the preamp and the amp (XLR and RCA versions available), and serve to "part out" the signal. The amp and main speakers handle the mid- to high stuff, and the lows go out to the two Vandy subs, powered at 300W each.

The difference it made in my system was astounding. One was good; two is better.
Thanks Rhanson739, you think am i correct in guessing they are the only such items on the market?

As I recall I saw a 2q in a Minneapolis dealers setup, aren't they on the humongous side?
Most, but not all, subwoofers offer a high-pass filter when you connect the sub via the speaker-level connections. You run the speaker wires from the amp to the sub, then from the sub to the main speakers. This is often a preset frequency filter and roll-off.

I have a pair of Vandi 2Wq subs, and swear by them. I did upgrade to the battery-biased outboard crossovers, though. They are not small. See the Vandersteen web site for more info and dimensions.
OK, this topic is related to a question I asked some time ago. Another answer to this situation is the Classe CP 800 preamp. It outputs for two channel setups like yours. It has an internal crossover. I own one. I use it on my Snell Type A V 5's which consist of two tower (38 htz to 20,000 htz) and two 18" bass units. Normally the system came with outboard active crossovers which are RCA only. I wanted better so I bought a Marchand crossover for splitting the signal. The bass was to die for but the upper frequencies lacked something. I thought that removing the Marchand unit might do the trick as I'd have a shorter signal path and fewer cables. The midrange and treble are now incredible with the Classe but the bass is now lazy. I used to be able to shake the walls if I wanted to. No can do now. I need to try a few more things. Does anyone know about the differences between LFE processing and an active crossover? Maybe the answer to audio bliss lies in unraveling this mystery. Joe
Schubert - Well, large is relative, I suppose. They were larger than I had expected, but since they tend to be placed in a corner, it's not a problem in our space.

I believe the Vandersteen setup is unique, but can't swear to it. But as Bondmanp says, I swear by them. The moment I placed them into my system, the overall sound improved tremendously.
There are several companies that build high pass filters into their subwoofers: Velodyne, Martin Logan, SVS are examples. Using the line level connections from your preamp to the sub and then from the sub's high-pass line level outputs to your amp(s) will remove the bass load from the amp(s) and speakers. This is biamping and does not impact the crossovers in your speakers. It is the connection approach I recommend.
Jnovak, I believe Classe CP 800 is doing bass management in the digital domain, whereas, your Marchand was analog. From the CP 800 docs:
Analog inputs may be routed through the ADC and processed for EQ, tone control and bass management (high pass filtering). Alternatively, sources may be identified as Analog Bypass, in which case they remain analog and full range throughout.
I would suspect the digital processing would be beneficial and wouldn't use the analog crossover.

Explain how you have things connected and maybe we can help.
Hello, I apologize for taking so long to respond back to you Bob Reynolds. My Dad is in and out of the hospital and my time is limited to family these days.
I had an hour yesterday so I played with the settings on the CP800 AGAIN. To back it up a bit, here is my setup:
Snell Type A V5- This consists of two towers(4 mid woofer and two midrange and one tweeter)and 2 18 inch subwoofers. My CD player is a Cary 306. I'm using a Classe
CA2200 amp and a Parasound 2100 on the bottom end. Previously, I used a Pass Labs preamp that I ran to a Marchand crossover. I use several brands of high end cable. With the Pass and the Marchand, the bass was to die for! If I wanted to crank it a little, I could shake the walls downstairs. The dogs would scramble and the wife would complain. The towers were missing something though. No live music sound. The soundstage was weak. The drivers seemed asleep. I thought I'd experiment with some home theater preamps like Anthem Statement D1 and the Parasound C2 (?).
Now the CP800. I was surprised how much preamp you can get for a few hundred dollars used. I didn't care for the Anthem. It isn;t designed for music. Too noisy. The Parasound was a surprise. Very nice and quiet. Not high end though. The Classe though---Oh Boy!! The towers on my Snells woke up! Super soundstage. The speakers disappeared. Fabulous. The 18 inch woofers died!! No life. Wimpy. The same has been true for all of the three preamps I mentioned.
Present setup- The CP800 is output; MAINS to the towers amp.. SUB and AUXILLARY ONE to the amp for the subs. NO Analogue bypass. The woofers do move but not like they should. I don't understand all the EQ functions. Classe says to have a qualified dealer set it up with proper equipment. I don't have a dealer. I bought it here on Audiogon. Any help is appreciated. Thank you. Joe