Odd subwoofer question.

… The problem with the vast majority of commercial subwoofers is that they are built to a price and take short cuts to make implementing them easier and less expensive.

Even F1 cars are built to a price point.
And spaceships.

… No subwoofer should be crossed over below 80 Hz. If  a subwoofer can not run up to 80 Hz without a noticeable degradation in sound quality it is a poor design. The best drivers are perfectly capable of running cleaning up to 150 Hz. The problems usually arise with the enclosure, crossover and amplifier.

You forgot port noise. 😁

… on an LFE then there may be good reasons to go from <20 to 80 Hz. And distortion harmonics can quickly get into the localisation freqs at 3rd or 4th harmonic.

Most people have a high threshold for distortion at sub frequencies.
(I am not sure 80Hz is a commandment, 50-120 Hz is a typical “range”, and 60-100Hz likely where the bell curve is thickest..

I prefer passive subwoofers because IMHE large class AB and A amplifiers make more dynamic bass than the class D amplifiers used in practically all subwoofers. I find it interesting that many audiophiles are willing to go to great lengths isolating their electronics from vibration but are willing to accept an amplifier in a vibration pressure cooker…

If there is any place for the efficiency of Class-D… it is in a subwoofer.
I am not sure there is any factual evidence that the Class-A is better for dynamic range than Class-D in kW sized subwoofer applications?

in my case eight 12" drivers, lots of power, each pair gets 2000 watts and digital bass management (crossovers and room control)

That is a lot of bass, and likely over the OP’s budget.
If one can tell if the subwoofer is on, then it is almost too much bass.

(IMO) It should be a bit hard to tell if it is on, but obvious when it is shut off. That hits a nice level relative to the rest of the spectrum.

Assuming that it is mostly used for reinforcing the bass, and not replacing the whole spectrum.

@jjss49 , Absolutely true (the last paragraph)

I have been living with less than ideal subwoofers since....1978. The benefits have always been worth the problems but accuracy in the lower octaves frequently suffered. I have been using ESLs almost exclusively since then with a 6 year diversion into Apogee Divas. Getting the low bass out of these speakers improves their performance by an order of magnitude. I have been chasing a subwoofer system that matches their accuracy since 1978. At this point in time the only commercial subwoofers I would consider are the Magico Q series and they have two major limitations, size and price. I can do better in DIY terms in both size and price. The last set I constructed are about 80% of the way there. The next set should be state of the art. 

The problem with the vast majority of commercial subwoofers is that they are built to a price and take short cuts to make implementing them easier and less expensive. A good example of this is the use of simple low pass filters instead of  full two way crossovers. There are compromises that they have to use in enclosure construction. Put you hand on your subwoofer while playing. That vibration you feel is distortion. There should not be any, even at the loudest volumes. Most main speakers benefit by having the low bass taken away from them to one degree or another depending on how high up into the midrange their subwoofer goes. The higher the greater is the benefit in terms of lowering distortion and increasing power handling. No subwoofer should be crossed over below 80 Hz. If  a subwoofer can not run up to 80 Hz without a noticeable degradation in sound quality it is a poor design. The best drivers are perfectly capable of running cleaning up to 150 Hz. The problems usually arise with the enclosure, crossover and amplifier. I prefer passive subwoofers because IMHE large class AB and A amplifiers make more dynamic bass than the class D amplifiers used in practically all subwoofers. I find it interesting that many audiophiles are willing to go to great lengths isolating their electronics from vibration but are willing to accept an amplifier in a vibration pressure cooker. The problem with high powered class A and AB amps is that they get hot which is highly problematic inside a subwoofer enclosure. Passive subwoofers allow you to use any amp and a multitude of great crossovers to achieve the best results. You can take any subwoofer and turn it into a passive one by disconnecting the internal electronics which is a viable option for someone who does not have the capability to build his own.

while @mijostyn 's points are salient to any subwoofer discussion, in my view and experience they are not practical obstacles to having subs (at least rel subs in my personal experience, but i know there are other excellent subs out there) work in a totally satisfactory manner for very high end systems for very discriminating listeners

i would also add that sub bass infomation is also very much about helping the system develop a very palpable sense of space and natural propogation of transient information approximating a real life listening or performance venue

Sub bass is very difficult. It is not just a matter of what you hear. It is more about what you feel. To get the right idea go to a small Jazz club like the Blue Note in NYC. Try to sit dead center of the band. Reproducing this level of sound quality at home is possible but it requires lots of subwoofer, in my case eight 12" drivers, lots of power, each pair gets 2000 watts and digital bass management (crossovers and room control). You have to remove as much bass as you can from the main speakers which will clean them up and increase their headroom by a substantial margin. I cross over at 100 Hz. 

The subwoofers themselves are another world of problems. Keeping the enclosure from resonating is extremely difficult as bass is very powerful. Put your hand on your subwoofer while playing. Feel the vibration? That is resonance and that is distortion. Ideally you would not feel anything other than a cold surface. Building such a subwoofer is very expensive and not viable commercially with only the Magico brave enough to give it a spin with their Q series. Since most of us are not up for spending $40K on a single subwoofer the DIYer is left to his own devices to make it work.  

Has anyone else tried a Vandersteen 2W?

They are around the OPs budget used, however it is uncertain whether the OP’s woofers are in polarity there, or whether they are inverted… in a 3 way the woofer and tweeter are often OK and the MR is inverted…

The invert switches are on a lot of gear, which suggests that they can be needed often.

I will certainly consider it. Thanks.

I’d strongly encourage you to at least try a sub as the benefits go well beyond adding bass and also greatly enhance imaging, soundstage, and overall sense of space.  The SVS 1000 Pro is only about 13” square and 15” depth, will get you down to an honest 20Hz (-3dB), comes with integration software, and this one available on their Outlet is only $575 with free shipping.  And you get a 45-day trial period so if it doesn’t work out for you (or your wife) you can simply return it with free return shipping.  Just trying to help as I know what a sub can do and think it’s at least worth giving a shot especially when SVS makes it so painless.  They also have great customer support if you ever need help with integration, etc. (probably can’t do much about the wife though).  Ok, that’s all I got and hope you get a chance to at least give a sub a try.  

https://www.svsound.com/products/sb-1000-pro-subwoofer

Thanks guys. A couple of thoughts.

To be honest I was hoping something for well under $500. The used market might help.

Not interested in a pair of subwoofers. It is only by my wife's good graces that the speakers are in our living room which is fairly formal. So I might be able to sneak one behind the couch but two would be pushing it.

I could try a used Sonos but was concerned about the SQ. I'm not looking for palpable home theater type stuff. However, if it did not work out for the living room I could stick it in one of the other rooms with Sonos speakers.

@mijostyn said:

If you like tight precise bass you are better off without subwoofers unless you have a lot of money to spend.

I'm guessing this is probably the case and I'm now kind of disinclined to go down this path.

@jjss49 said:

there are some people who don’t get the integration correct, while others unfortunately struggle with a sort of ’reverse placebo effect’ where they mentally can’t get their mind to get out of the way in allowing themselves to hear and accept that well done, subwoofer-supported bass is ’correct’...

You probably just described me perfectly. As is, the 6Ts are pretty good with the right recordings. I'd probably go nuts trying to get things back to sounding the way they do without a sub.

So, thanks guys. All things considered I think I'll leave well enough alone.

rel subs are best used with their high level input, but they do have lfe/rca inputs as well

it would be safe to say any modern rel sub would be plenty fast for any application where the main amp is a sonos amp (provided the user follows instructions and properly integrates it/them)

there are some people who don’t get the integration correct, while others unfortunately struggle with a sort of ’reverse placebo effect’ where they mentally can’t get their mind to get out of the way in allowing themselves to hear and accept that well done, subwoofer-supported bass is ’correct’...

If you like tight precise bass you are better off without subwoofers unless you have a lot of money to spend. The only commercial subs I have heard that produce "tight, precise bass" are the Magico Q series subs. To do it totally right you need a digital preamp with bass management and room control. I prefer passive subs with out board amplifiers.

I have a Sonos system in my house and have one of their subs in my exercise room. It is not tight and precise but it does add bass to the system and it integrates with their other equipment nicely. It is also big fun to turn the whole house on, sounds like a big venue. 

Since you own SONOS amp, why not try their subwoofer. I am using three of them in different systems and the integration is seamless along with superb bass. Setup and tweaking is easy through SONOS app.

If you wanna go ‘wired’ conventional subwoofer route, my money is on REL for 2-ch  systems. 

Check out the line of REL subs.

All good suggestions, I went with JL Audio due to their DSP built in. Really helps match the sub to your room and other speakers. The size of the room is critical. I had to go with their ten inch as my room was just too a bit too small for the 12 inch. So careful on the size you get, you need a good size room for a 12 inch woofer to sound tight and precise. Too small a room and you'll get a mushy sound. 

+1 on the SB1000 Pro, but I’d absolutely get 2 at about $1150 for the pair if it’s in your budget.  Hey, with SVS’s generous and risk-free return policy you could try two and send back one or both if they don’t work out, but my bet is you’ll keep both.  FWIW, and best of luck. 

The svs SB-1000 Pro has an app to help you set up the subwoofer and a 45 day trial period. 

Inate,

In an effort to learn how to assemble a good system I visited

people whose opinions seemed well founded in order to hear 

and see what they did. 

The ones with what I felt were the best systems all used subs.

Prior to that I felt like you did about them. 

I decided to do a toe dip by adding the REL t5x $700. An 8" down-firing sub.

Small footprint. No advertising to look at.  Love the thing!

A hard core audiophile would buy 4 subs with a separate amp.

I am not that guy. 

When I turn on my system now and start to listen I know immediately if I

have neglected to turn on the sub. I should just leave it on 24/7.

Your system is superb. A sub will put smile on your face. REL has an

annual promo on right now. They raised the price $100 from 2021 and offer

you $50 off. Such a deal!  

There is a trial period though.

Thanks. That's good to know.

Using the sub output, then a sealed box will have a lower group delay than a ported box, so it should be ‘tighter’…