Need advise on subwoofer for my KEF Q series with onkyo tx-nr809b receiver

- Where are you located (city, country)?
- What is your budget?
- How big is your HT space?

Assuming you're in the United States, and based on a very quick Google of prices for the KEF and Polk subs, I'd say don't bother with either one. Here are just a few alternatives:
- SVS PB-12NSD, SB-12NSD or PB-1000
- Outlaw LFM-1 EX or LFM-1 Plus
- PowerSoundAudio (PSA) XS-15

Are any of the KEF Q series subwoofers available to you? I'd recommend one of those over the Polk.

I would check to see if SVS or HSU ship to Canada - my recollection is they do. (Just slower shipping if you want to keep the price down.) IMO both of them offer better value on subs than KEF. (And I'm a KEF fan!)

+1 I'm sure many of the ID brands will ship to Canada but it may be cost prohibitive.

I would check into the shipping costs for SVS, HSU, or Outlaw. As sdg4vfx mentioned, they are a much better value. It's not that KEF subs are bad they're just a bit expensive for what you get. That being said, I would go with the Q400 if the options above don't work out for you.

I'm in Canada, too. SVS subs are available in Canada through SVS' Canadian distributor, SonicBoomAudio.com. Last I checked (a day or two ago), prices up here on the three subs I listed were the same as in the U.S., although tax(es) and shipping are extra.
Edited by eljaycanuck - 1/5/13 at 7:12pm

This is the way to go. Can't go wrong with SVS.

That's great. SVS would definitely be the way to go then.

I have the Q900's and C600 also and I run the SVS PC12 plus with them and it sounds great.

The frequency response on the soundstage is listed as 38Hz-150Hz. That is pretty poor for a HT usage. You should look for something that has solid response down to around 20hz. The Cambridge X500 is not that great given it's already 6hz down at 23hz.

Read this review of the SVS PB12-NSD. There is a reason everyone is telling you to go SVS. Their subs are considered top of the class in terms of performance/price over on the AVS subwoofer forum. They generally outperform traditional brick and mortar store speaker subs for the money unless you are getting the B&M store brands for about %50 off MSRP.

Now if there is some reason that the SVS subs wouldn't work for you, explain so we can help you find an alternative.

You can contact SonicBoomAudio (SBA) - SVS' Canadian distributor - by phone or e-mail. You will pay taxes and shipping. No customs duties because, as I already mentioned, SonicBoomAudio is located in Canada.
There's an advantage in the sense that you can demo it and, depending on the shop, possibly return it if you don't like it. The disadvantage is that you don't get the same value (performance for money) as buying Internet-direct (ID).

With ID companies in the U.S., you can occasionally demo for the cost of return shipping only, or - in the case of SVS' recent Black Friday sale, during which they paid the cost of return shipping - you can demo for no cost at all.

Up here in Canada, demo-ing will most likely cost you shipping both ways. But the option is there.

If you do your research (forums, reviews, etc.) and talk to the comany reps (Mason at SBA is a good guy to deal with), odds are you won't need to return anything.

-- Edit --
Another Canadian option is Funk Audio. Not sure if they have anything in your price range, though.
Edited by eljaycanuck - 1/6/13 at 2:50pm

KEF Kube-2
- 10" driver
- 200W amp
- 35Hz @ -3dB
- $549 + tax(?)

SVS PB-1000
- 10" driver
- 300W RMS amp
- 20Hz @ -3dB
- $499 + tax + shipping*

(*I got a shipping estimate of $48 from SBA for the PB-1000 from Richmond Hill, ON to Vancouver, BC.)

SVS SB-1000
- 12" driver
- 300W amp
- 24Hz @ -3dB
- $499 + tax + shipping

I'd take either SVS over the KEF without a second thought.

But why buy a subwoofer rated 35Hz - 150Hz when your main speakers go lower than that? The Kef Kube 2 is also very small and won't have a lot of output for a 10" sub.

The SVS PB-1000 is a much better sub for the money at $499 + shipping and taxes. But it would be worth investing in even a higher model. The Kef Q900s and Q600c deserve a good subwoofer to go with them.

You beat me to it

I'll let you have the next one...

+1 Or is it +4 or +5 by now ; )

I recently got a SVS SB12-NSD and am very happy with it, esp. for music. (Replaced an ML Dynamo I bought used but new cost twice as much as the SVS.) The newer, less expensive 1000 series are also getting good reviews.

The specs say the Q400 goes lower than the Kube2 (better for HT), also it is the sub designed to go with your Q series speakers. So based on that I would recommend the Q400.

Because your LCR front speakers are all full range (i.e. have lower extension) I would experiment with a lower crossover than the HT standard 80 so that the sub takes over less freq. range. Some reviews I've read on the KEF subs, as well as the B&W subs, mention that quickness and detail are a bit sub par with more complex/full sounds so a lower crossover might help compensate for that (i.e. simpler or fewer sounds will be easier for the sub to resolve quickly/accurately).

For stereo music the Q90's are fine on their own so I'd program no sub for 2-channel listening.

The Q400 is a 10" sealed sub with a 200w amplifier, and it would be best suited for small room.

How big is your room, including any areas that open to it?

The apparent difference is that the Kube2 is a 10" + passive radiator (a kind of vented box) design, while the q400 appears to be very similar except that it is a sealed box.

The Kube2 can be expected to be flat to a slightly lower frequency, have a bit more efficiency, but have a sharper bass rolloff, all other things being equal. The spec sheets don't speak one way or the other to how identical they actually are.

The added efficiency of the Kube2 means that maybe it can get a little louder (but far less than twice as loud) than its sealed box brother.

If you are using this subwoofer with an AVR with sophisticated system tuning facilities (e.g. Audyssey Multieq) many of the more audible differences between these devices will be largely or entirely erased.

I think choosing either one is a safe choice. Pick the one whose looks you like better, the one that conceptually makes you feel better or the one that is cheaper.

If you want max bass loudness, pick the Kube. Probably.