Subwoofer for "seamless" integration with Zu Druid

I've had a pair of Zu Druid Mk-iv's for about 3 months now. I'm really digging them, but miss the lower octaves. I don't know much about subwoofer design or manufacturers. Anything that would give me solid response down to 30hz (or even lower without sacrificing speed) but still be fast and tight.

What is the best design for integrating into speakers such as the Zu's (sealed, ported, with passive driver, etc.) and what brands/models should I be looking at? I'd like to spend no more than $1,000.

The REL's are reviewed well, and the Zu Method and Mini Method seem an obvious choice, but aren't manufactured anymore and are scarce on audiogon.

Would you care to list the rest of your system, amp, source, cables?
Sure -

I've got a Wavelength Brick DAC feeding a Musical Fidelity A308 integrated, DH Labs Silver Sonic BL-1 interconnects and DH Labs T-14 speaker cable -> Zu Druid Mk.iv (non-2008).

I'm coming from Vandersteen 2Ce's so I know this system will produce the bass I'm looking for if the speakers are capable. I listen to a lot of pop/rock and electronic music where a lot of it is obviously missing without the sub 40hz. :)
Take a look at the TBI subs for sale here on the Gone.
The seller has a pair but it looks like he will split them up and just sell one.
I had these awhile back and were the finest subs that I have heard, very fast with a nice organic sound.
Good Luck, Tish
PS The reason I sold them was because I purchased full range speakers that go down to 27hz. (Sonist Concerto 4's)
How about the zu undertone.
You need a REL Britania series B2,or B3 you can find these used at very nice is the only way to get seemless integration with your Druids. Check it out.

I am very familiar with the Druids, having listened to them at a friends house. He bought them new, and they took many hundreds of hours to fully break in, with bass being the most noticeable during the process. His bass is so good, some have even asked, "Where's the subwoofer?"

Have you experimented with the gap between the bottom of the speaker and the floor. This definitely affects the bass response.

Also, the impedance curves of the Druid and Vandersteen are quite different. A speaker cable can work great with one speaker and not so well with another. Myself and a few other friends have experienced this with various speakers and cables.

Have you done anything with your power, dedicated lines, upgraded outlet, power conditioner?

One thing to keep in mind is that the sound of Zu speakers is extremely coherent, and that will be compromised when you add a subwoofer.

BTW, the MF A308, great amp, I have one as well.
My experience may not be very relevant since my Druids are somewhat modified. Anyway, I have had great success using two JL Fathom f110 with my Druids. Features such as inbuilt auto dsp, phase, and roll-off options provided by these subs makes it fairly easy to achieve good integration. I use two because I am a bass-freak but one should be adequate and can be acquired used at your budget.
A good sub will NOT compromise the coherency of main speakers if used properly, especially if you blend it in where the main speaker starts losing its ability to make bass, and you keep the sub at a reasonable level. Low frequencies are more than simply bass notes...they are part of the ambience of real music in the real world. Once you have a good sub dialed in everything gets feel better about the world, food tastes better, and you personally become more likeable and slightly better looking.
I have a pair of Zu Essence speakers with the upgraded nanotech drivers. I supplement my bass with a Zu Mini Method subwoofer. The combination is fantastic. The Mini Method is an amazing little subwoofer. It integrates seamlessly with my Essence speakers, no compromise at all. Closed port subwoofers are incredibly fast, only sound boomy if the setup is entirely awry, and are a cinch to integrate with a copasetic set of speakers. I know that Zu Subwoofers rarely come up on the used market, but, if i were you, I would be patient and keep my eyes peeled for one to come up for sale. Someone sold a Zu Method, here on Audiogon, a couple of weeks ago and Zu Promos just sold a Mini Method on Ebay three days ago. So, even if they are somewhat rare, they still show up for sale at times.

Good luck,

I own the DruidV and a pair of Zu Undertone subwoofers. It is an excellent combination. The integration of the subwoofers is subtle but very noticeable when they are turned off. It gets the sound down into the lower end. Talk with the folks at Zu.
You should definitely call Zu. They may have a few remaining Methods, etc available.
I know nothing about your speakers, but subs with Maggies are notoriously difficult to blend. The Gallo TR 3s I got are marvelous with my 1.7s...might be worth a look for you.
Over your budget, but Zu's Undertone is excellent with my Druid V speakers. It blends in perfectly.

Talk to Sean, he might have some b-stocks for a good price.
I have a pair of MJ Acoustics Ref 100 which work well with my Zu Druids. I find them to be quit musical and to blend in well, as do the REL Strata. It seems most high powered subs do not integrate well, so lower powered musical subs worked best, for me and my Zu Druid Speakers. I am looking forward to hearing the Zu Undertones though.