Go for sub or larger speakers?

To sub, or not to sub? I'm with the "depends on the room" contingent. In some rooms you just cant get "fullrange" speakers to work (without correction).

One more thing you might want to consider: if your main speakers are ported, you may want to plug the ports. In my experience, if your mains go relatively low it can sometimes help integration with the sub. On smaller speakers I usually leave them open. Lots of variables to play with, all rooms and set-ups differ.

Edorr,

I've definitely thought about the x-over issue. I borrowed a (used) Marchand from a local dealer for comparison and it worked well, but it was noisy, which was more intrusive than the NHT. Of course, who knows whether that was just due to the condition of that one used example.

The main reason I haven't pursued it is that I can't decide whether to go for a high end HT pre/pro solution or a higher "pedigree" stand alone x-over. I'm kind of embarassed to admit that my power up regime -1)preamp, 2)SMS-1, 3) NHT, 4) DAC, 5) power amp has me thinking that a pre-pro (Theta?) replacing #s 1 thru 4 might be nice. Not sure I'm ready to punt and go that way, but I'm not sure that I'm not ready, either.

But, your point is definitely taken.

Marty

I see that the thread has run in the direction of sub integration. I found that this was actually difficult for all the caveats which appear as aside or minor conditions to be aware of.
You must count the following; room difficulties, with no absolute answer. This is reasonable because no two rooms are alike, so it's reiteritive or back and forth experimentation big time. This can be a source of uncertainty and frustration.
The appropriate frequency to roll off the sub activity, Stanwal suggests 25 cycles. This means only the sub will be playing the lowest 5Hz at the signal strength before being diminished at a non specified rate. To me this hardly seems worth it as virtually no music exists at such depth. To Stanwal's credit he says it is unoticible except for bringing fullness to the sound. So you have to guess at integrating your sub/s at the imagined low frequency where your regular woofers fail to suffice. Let's say anything below 60-80 or so cycles, however integration at this level can sound bad and was hard to do in my own experience.
The use of external crossovers which of course means more signal manipulation and depending on where you put it potentially with the mid and high freq also.
The scheme of ext xover to the sub equalizer and of course the sub's requirement for an equalizer.
The sub speed matching and integrating with you speakers response.
I am sure you will find more if you read carefully.
This is a long winded way of saying I agree leave it up to the Speaker engineers and buy a speaker with sufficient low end to do justice to the music. The music you actually play not the sound effects many subs are meant for and you specifically don't want it for.
Good luck

Marty,

You could pick up a used Theta Casablance III with 1 Xtreme card for about $4,000, and use it in a 2.1 application. I own a CBIII with XTreme card so I can give you some advice here. From what I gather you want to consolidate boxes, and need four things; Preamp, DAC, EQ and Xover. The CBIII will not give you EQ, so you still need yout SMS-1. The Xtreme card is a good (10 year old) DAC in a MCH application, but a modern 2 channel DAC beats it hands down (I have a PS Audio Perfect Wave which is a better DAC). Xover flexibility is second to none in the CBIII - no issues here. However, your LS25 is a far better preamp than the CBIII (I use a Theta Six Shooter for preamp, which is far better than the analog bypass in the CBIII). In summary, depending on what DAC you are currently using, you will very likely take a big sound quality hit with a CBIII, still have a two box solution, all for the questionable benefit of having a good Xover in a box 40lbs box (with I bunch of features you don't need).

A far more promising alternative is to look into the TACT 2.2 digital preamps with build in EQ and Xover. This has all the four functions you need in one box. I suspect the (optional) buld in DAC is the weakest link - but not to worry, it has digital out so you can hook it up to an External DAC. The only wildcard here is you are going from volume control with your LS25 tube preamp, to doing it in the digital domain. This would be anathema for purists, but since you are considering a CBIII and are not loosing any sleep over using a cheap Xover in an otherwise high grade system, obviously you are not a purist (I say this as a positive).