Subwoofer with 2 channel stereo setup

My system is rapidly growing. I can't help it :)
The whole system now is integrated amp(DK Design MK1), turntable (Oracle Delphi MK 1), phone MC pre pre-amp and two speakers (ML Aerios i).
Now to finilize it I am thinking about getting a powered sub. The decent sub is another $2,000 investment.
I wonder if for-music-only-listening stereo (not for movie watching) it is A MUST upgrade? Does an introduction of subwoofer to a system will make a big difference?
Depends on the system and the sub. I never heard of anyone having a really easy time trying to integrate a subwoofer with the existing system. Just always seems to be very challenging.

The best advice, I think, is to demo it, if you can, in your room with your system.
I agree with S7horton. That is, it will depend on the system, speaker / room interface and the type of music that you listen to. I would not consider it necessary unless you listened to a lot of bass heavy music at higher than average levels and / or your system / speakers were either lean sounding and / or not capable of extended bass at higher outputs. I wouldn't go this route unless you were completely satisfied with the idea that you were already obtaining optimum performance from what you've got. Adding more to a system simply makes it more complex and harder to set-up. I'm a firm believer in the "KISS" theory for the average enthusiast that isnt' technically inclined. For those that don't know what KISS means, it is an abbreviation for "Keep It Simple, Stupid" : ) Sean
For sure it makes a difference in certain systems! Integrating a subwoofer into a system isn't easy but it ain't all that hard either. I for one couldn't live without it. I like it so much, I've seriously considered buying a second one to run in stereo. Only question I have is..what brought you to the conclusion you have to spend $2000 to get a decent musical sub? The KISS theory works well too! :-)
Gmood1: What if your "mains" were solid to well into the low 20's or even lower? Could you live without a sub then? That's why i said that it would be system dependent : ) Sean
Sean that's why I said certain systems.The last time I checked the Aeon I only gets down to around 40 hz. I agree with you ...when I had floorstanders that could do this no sub was needed. Of course the bass was not as tight as it is now with sealed enclosures doing the low frequency duties.

I couldn't help myself ...I went ahead and picked up another matching sealed 12 inch sub for my system today. Can't wait to get it tuned in with the other one.
Now we are cooking with oil ! :-)
I have main speakers that go into the 20 Hz region, but setting the crossover at 80 Hz, thereby freeing the mains of LF duty, makes the system sound even more transparent and open, and seems to expand the sound stage while maintaining precise imaging.

For my purposes I selected an REL sub. The reasons for this are the unique high level (music) and low level (LFE) connections and set-up. The REL subs a traditional rca interconnect for the LFE channel. However it also uses a second proprietary connection from the main speaker (L&R) outputs to the sub. There is a separate level control for each connection that provides for fine tune matching of levels for music or movies.

I am very pleased with this arrangement and believe it to be the best solution for integrating a sub into a primarily music system.
Mwheelerk this may work in some systems. But you have to wonder, how much signal degradation is going on running your mains signal through two sets of crossovers.

One pair of crossovers does enough damage. Two pair cannot be good for the integrity of the music. This is why I use the RCA inputs allowing my speakers to run full range with a natural smooth roll off above 50 hz.The sub then picks up around 55 or 60 hz and goes flat to 30 hz. The other way and maybe the best way,is to run a digital crossover before the signal goes to either your mains or the sub bypassing the passive crossovers in both.
I have a sub with my Totem Forests. I bought it before I started using the DK Designs VS1 MkII. Now that I have the VS1, I generally keep the sub off or the level way down. The only time I use it is when I have the volume low with music that I know has a lot of good base or when I want some louder base and want to make the house shake a bit more (this doesn't add to the music quality - just to aesthetic of base). I have a largish room that has a lot of glass and wood which tends to be a bit bright. I had been using a less powerful amp, and previously the base was not very tight, especially a louder levels, hence the powered sub made sense. I do not have this issue now. With my current amp, I would not have purchased a sub! BTW, I'm using an Arcam Cd23, Dk interconnects, and a Totem Thunder sub. It's a musical sub, and I generally like it's quality, this point, I wish I had put the extra $2k+ into speakers.

I think the question that you need to ask yourself you like the music your system puts out in the room that it is in? If yes, then a sub is an expensive addition for (possibly)little gain. If no, a sub might or might not fix your problem.

I've just purchased Martin Logan Grotto sub($960) in local Magnolia HIFI.
So my system now consists of Oracle Delphi MK-1 turntable with Denon moving coil cartridge. The signal then goes to Music Reference tube phono pre-preamp. And then to DK Design MK 1 amp wich has phone stage built in. Martin Logan 'Aerius i' with brand new panels (membranes) with new Grotto sub generate the sound.
I have to admit that the sound is beautiful. But I still wish for better one. The affect of "LIVE MUSICIANS STANDING AND PLAYING IN MY ROOM" wasn't achieved. As I understand I'm now approaching the point where the "real" jorney for a "perfect" sound begins. It is probably a time to stop buying and start listening music instead a stereo equipment.
Donbellphd: I can see how this approach would help a speaker where the woofer covered much more than just the last few octaves i.e. was more of a mid-woofer than a woofer. Woofers really shouldn't go up much above 200 Hz or so, otherwise, they tend to run into problems like those that the addition of the REL solved for you.

Sputniks: With what you have, speaker placement ( mains ) will be the make-it or break-it factor. Once you get that as good as it gets, getting the sub to blend in would be the next step. Don't introduce more variables into the equation until you are certain that the bare essentials are covered as well as possible. Sean

I first noticed the improvement in transaparency, openness, and soundstage when I had been using KEF Reference 102/2s with a Velodyne HGS-10,; it seemed intuitive to limit the frequency range, given the small size of the 102/2s. When I substituted the much larger KEF Reference 104/2s, I decided to send the full frequency range to them. But when a Velodyne HGS-15 from a local source was delivered by an installer very familiar with high-end audio, he suggested I use Proceed's 80 Hz crossover even with the 104/2s. I was surprised to find the the same effect as with the smaller speakers.

The HGS-15 sits on an Auralex SubDude, and blends seamlessly with the KEFs. For movies and HDTV, surrounds are a pair of 102/2s with a KEF 200 C center speaker. The other pair of 102/2s and the HGS-10 have been moved to a secondary system, and provide good sound for the living room.

I suggest to audition and give it a try on your system.
Most of all trust your ears.

Just like you I was a skeptic unitl 2 days ago I brought home a Martin Logan Depth to demo with my Ascent of 2 years.

I opt for the Depth due to its size and ample performance of seamless matching my system. It is AWSOME....easy to set-up. Authorize dealer let me take their demo unit while mine is on order. My room is a 14x15x9. I listen to jazz, classical rock,and vocals. Hope this helps...
You want a Velodyne DD series sub.