Adding a sub - what will I loose?

10 Grand for a sub,lol......more power 2 ya

What you will lose is realism, especially for the timbres of acoustic instruments...

IME, you will lose nothing - if you get it right - and you will likely gain a ton.

I've used a lot of combinations successfully, but the common denominator has been a sub controller. I think that getting seamless integration of your sub(s) is exponentially more difficult if you try to do it by ear. I also think that digital room EQ (at least for the subwoofer signal) is tremendously beneficial.

Until recently, I used a stand-alone Velodyne SMS-1 sub controller. Last week, I replaced my outboard x-over (NHT X-2), preamp (ARC LS 25), dac (Benchmark DAC-1), and sub-controller (Velo SMS-1) with an Audyssey XT32 enabled pre-pro (Onkyo 5508).

While I have not completely tendered my "official audiophile merit badge and ID card" (I still have the ARC gear and a bunch of Joule, Cary, PL, etc), I will say this system sounds awfully good to me.

Marty

The quality of the high pass filter to your main speakers is of primary importance. I do mine with a super high quality resistor/capacitor network (latest nude Vishay and Mundorf Silver/Gold). The high pass filters built into most subs suck big time.

I have agree you should only gain when set up properly. The KEY word is setup properly. When I first got my Dyn C1's I thought my Rel B3 was slow sounding compared to the C1's without the sub. Turns out I had it set up all wrong. Crossed over way to high and the volume was too high. I could always hear where the sub was. Once I had that set properly it still sounded slow to me. That was because I had the timing wrong (physical position). The low bass sound wave lagged the original signal. Had to move it about forward 4". Then I was a happy camper until I started reading these posts regarding subs and many stated the cable made a huge difference. So on a whim I ordered a Nordost baseline sub cable made to Rel spec. Holy Moly what a difference I heard. The attack and decay didn't exist in the stock Rel cable.

That being said it was all for the lowest bass that my speakers couldn't reproduce. I will add as a bonus that the mids actually sound better too (especially acoustic guitars - sorry Learsfool but I strongly disagree now that mine is set up right and I would agree if not set up properly). Nothing earth shattering like the low bass but just a hair better. On occasion I will disconnect the sub and it amazes me how few recordings have a real low bass.

Tghooper I don't have an external crossover so I can't comment on crossing them over that high. I have mixed feelings about doing that. My speakers are rated 45 - 22khz and my crossover is set at 41hz on the sub. Besides my sub cable is 5 1/2m and my tube integrated only has pre out but no amp in. Either way I wouldn't want 11m of cable between my pre out and amp in.

So in the end if your are considering a sub I say the 'nike' slogan - JUST DO IT !!! Just remember if it doesn't sound right you don't have it set up properly.

Good Luck