Adding a sub - what will I loose?


It seems that adding another piece of equipment to the audio chain would degrade the sound quality to the main speakers (air, immediacy, the mid range, etc). Or am I way off here??

Currently have a preamp with no sub-out and low output tube amp. Plan to use line level to the sub and then out to the amp. That way speakers would not play full range (above 80hz).

tghooper
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
10 grands for a sub does hurt but better than for pair of cables. I like two subs, I like even more full-range big speakers. So to answer your question - the answer is unknown. It depends.