REL Vs SVS for 2 channel music listening

I have Zu Omen Defs connected to a NuForce STA200 (class a/b) amp. REL has suggested a T9/i

SVS has a cheaper SB-2000 which seems to be closer for half the price

I've read numerous places that REL is way overpriced and SVS is great for music. I am aware of Zu's subs...would like to keep the price under a grand if possible. 

JL Audio E110 or E112 (not fathoms) are my recommendation.  Especially if you can use the crossover.
Thanks. Many have suggested Rytmick subs...however...their website it too wordy and all over the place
The SVS appears to be the better value. I use a 10 year old REL B3 with great results, but if I  were shopping right now, nothing in the REL line compares in price/specs.

That's a great price, I would consider 2
Post removed 
REL or Vandersteen. Had a Rythmik and SVS. Did not like build quality of Rythmik and SVS customer service was very bad, driver failed on SVS. I have heard great things about JL Audio, and I would try them myself someday.
My thinking now is to keep things simple. I try to find speakers with bass, where a sub is not needed. Or a well designed speaker with active amps inside, like Vandersteen does. The SWARM sub system by AudioKinesis is the only one I would try with a large room.
I would not use $$ as your main driving parameter in introducing a subwoofer into a 2-channel audio system. You will run into that inescapable and unavoidable basic tenet in the crazy hobby: you get what you pay for - full stop.

I am  reposting a prior post that is one of the best articles out about why funding a good subwoofer is hard to find.

All subs are not created equal, and there is no "silver bullet" magic solution. Similarly, room characteristics and placement are contributing factors.

The following article has been posted before and is rehashed again below - one of the better reads in the subwoofer selection process .... one of the best articles I've seen discussing this....

August 3, 2008 ... subwoofer/

"…And Why a Really Good Subwoofer is so Hard to Find

Audiophiles and music lovers are missing out on one of the most dramatic improvements they can make to their audio system: Powered Subwoofers.

Most audiophiles won’t even use the word “subwoofer” in public, let alone plug one in to their precious systems. There is a kind of snobbery that exists in the world of high-end audio aimed primarily at receivers, car audio, home theater and especially subwoofers. As a matter of fact, subwoofers are responsible for many people disliking both car audio and home theater, since it is the subwoofer in both of those situations that tends to call attention to the system and cause many of the problems.

The truth of the matter is that subwoofers have fully earned their bad reputation. They usually suck. Most of them sound boomy, muddy and out of control with an obnoxious bass overhang that lingers so long as to blur most of the musical information up until the next bass note is struck.

We have all had our fair share of bad subwoofer experiences, whether it’s from a nearby car thumping so loud that it appears to be bouncing up off the road, or a home theater with such overblown bass that it causes you to feel nauseous half-way through the movie. You would think that high-end audio manufacturers would be above all of that, but you would be wrong. In many cases, their subwoofers are almost as bad as the mass-market models because they too, are trying to capitalize on the home theater trend that is sweeping the land.

You see, it’s very difficult and expensive to build a good subwoofer. One reason is that a sub has to move a tremendous amount of air, which places big demands on the driver (or drivers). Moving lots of air requires a lot of power and that means an amp with a huge power supply, which can cost huge money.

Finally, in trying to move all of this air, the driver (or drivers) which operate in an enclosure, create tremendous pressure inside of the box itself. The cabinet walls must be able to handle this pressure without flexing or resonating. Building such a box involves heavy damping and bracing which gets very expensive. When you consider these requirements, you quickly realize that it is virtually impossible to build a really good subwoofer (I mean good enough for a high-end music system) for under $1000. Yet most of the subwoofers out there sell for between $500 and $900. Manufacturers do this because their marketing research has shown them that that is what people want to spend on a sub, never mind the fact that what people want to spend and what it takes to get the job done right may be two different things. The result is that even most high-end manufacturers are putting out poorly constructed subwoofers that just don’t sound very good.

I don’t want to give you the impression that anyone who really wants to can build a good subwoofer so long as they are willing to throw enough money at the problem, because that really isn’t true either. There are some pretty expensive and well-constructed subwoofers out there that you would never want to plug into your music system because they would most certainly make the sound worse.

Why? Because of their crossovers.

A crossover is inserted into your signal path in order to remove the lowest frequencies (the deep bass) from your main speakers so that they no longer have to do all of the dirty work. The deep bass will instead be dealt with by the subwoofer.

The #1 benefit of adding a high quality subwoofer to your system is not how it further extends the bass response, but how it can dramatically improve the sound of your existing power amp and main speakers from the midrange on up. That, my friends, is by far the most compelling reason to add a sub to your high-end music system. Once your main speakers are freed from the burden of making deep bass, they will sound cleaner, faster and clearer, especially in the midrange and midbass.

They will also image way better because there will be far less air pressure and therefore resonance and vibration affecting their cabinet walls.

And since the power required to make the deep bass is provided by the subwoofer’s built-in amplifier, your main power amp will be free from that burden and begin to sound like a much more powerful amplifier.

The one big problem with all of this is that you need a crossover to roll off the deep bass in your system and achieve all of these benefits. And the crossover that comes with almost every subwoofer on the market will cause more damage to your signal than can be overcome by these benefits. That is the main reason that audiophiles refuse to consider adding subwoofers, even very expensive ones with well built cabinets.

Enter the Vandersteen 2Wq 300 watt powered subwoofer. This is the only subwoofer that is specifically designed to be inserted into the highest of high-end music systems without doing any harm to the precious signal.

So how does Vandersteen do it?

Simply. In fact his crossover scheme is so ingeniously simple that it’s a wonder nobody else thought of doing it the same way. I’ll spare you an in-depth description and just say that the only thing you end up inserting into your system is a couple of high quality capacitors. That’s it, nothing more!

No additional wires or gadgets enter your signal path. Hell, you don’t even have to disconnect the wire between your amp and speakers to add this subwoofer. The model 2Wq sub uses the same basic crossover scheme as the $15,000 flagship Model 5As. As a matter of fact, you can even run the specially designed Model 5A crossovers (M5-HP) with the 2Wq if you want the most transparent sound imaginable.

So what about the other reason to add a subwoofer to your system: for more powerful and extended bass? I don’t care how big your main speakers are, they’re no match for a good subwoofer in the bass.

A really good subwoofer can run rings around the best floorstanding speakers when it comes to bass extension, power and control because it is designed to be good at that and nothing but that, whereas main speakers have to be good at higher frequencies as well. Ideally, you want two subwoofers so that you have true stereo separation down deep into the bass. Stereo subs can also help to lessen room interaction problems by providing two discrete sources of bass information. Remember, if you can’t afford to buy two subwoofers at once, you can always add the second one later. Adding a pair of 300 watt powered subwoofers is exactly like adding a pair of 300 watt monoblock amplifiers to your system and upgrading to a pair of better main speakers at the same time. The beauty is that you don’t have to replace your main power amp or speakers to do it.

But there is a problem here as well.

Everything comes at a price, and the price you pay with most subwoofers is that when you add them and their built-in amplifiers to your system, they don’t tend to blend or integrate well with the sound of your power amp and speakers. This is especially true if you own a tube amp, because the character of your amp is nothing like the character of the big solid-state amp that is built into most subwoofers.

The result is that your system sounds split in half. You can hear where one part of the system leaves off (namely your amp and speakers) and where the other part takes over (the sub and its amp). This is a HUGE problem for audiophiles who aren’t willing to destroy their system’s coherence for additional power and bass extension.

Fortunately, Vandersteen has the perfect solution for this problem that is, again, so simple, I wonder why nobody else thought of it first. His solution is to build a very powerful 300 watt amplifier that strictly provides the huge current needed to drive the subwoofer. You can think of this amplifier as only half of an amplifier; or just the power portion of an amplifier. The release of this power is controlled by the signal that is provided by your power amp. Vandersteen’s amplifier needs a voltage to modulate its current output, and what better place to get that voltage than from your main power amp? This way, your power amplifier is directly responsible for the sonic character of the deep bass coming from the subwoofer because it provides the necessary voltage signal. This voltage signal contains the unique and characteristic sound of your main power amplifier and insures that that character is maintained in the sound of the subwoofer itself. The beauty of it is that your amplifier is only providing a voltage reference and no actual current, so it is not taxed with the burden of “driving” the subwoofer in any way. As a matter of fact, your amplifier doesn’t even know that the sub is connected to it. The 2Wq’s potential is almost unlimited given that it will ratchet up its performance as you improve your power amp. Remember that you always want your subwoofer to sound just like your power amp. No better, no worse. NO DIFFERENT!

After having spent time with the amazing Vandersteen Model 5A loudspeakers with their 400-watt powered, metal cone subwoofers, we were reminded of the sound we had with the awesome Audio Research Reference 600 mono power amps. With the Ref 600s there was a sense of effortlessness, openness and unrestricted dynamic freedom that we have only otherwise heard with live unamplified music.

Listening to those monstrously powerful amps made us realize that all other systems sound compressed by comparison. Only when we heard the new Vandersteen Model 5As with their hugely powerful built-in subwoofers, did we again have a strikingly similar sonic experience. The reason is that the Model 5As provide a total of 800 high-quality watts, to which you have to remember to add the power of the amp we were using, the ARC VT-100, at 200 watts.

This means we were listening to about 1000 total watts of amplifier power – not far from the 1200 total watts provided by the Ref 600s. With the Vandersteen subwoofer crossover and amplifier, you are able to get those hundreds of subwoofer watts to blend seamlessly and even take on the character of the ARC VT-100. It’s amazing! What’s even better is that the price of the system with the Model 5As and the VT-100 is under half the cost of the Ref 600s alone! Since this discovery, we have achieved the same kind of unbelievable dynamics and seamless blending with ProAc loudspeakers and twin Vandersteen 2Wq 300 watt powered subs.

So, if you want the sound of Ref 600s but cannot afford them, buy a pair of Model 5As or your favorite pair of ProAcs plus a couple of 2Wq subwoofers and mate them with a VT100 and you’ll get surprisingly close.

You can cut the cost even further by running a pair of Vandersteen 2Wq 300-watt subwoofers with your existing speakers.

Or mate a pair of 2Wqs with your favorite ProAc. In any case, it is the magic of SUBWOOFERS that allows this to happen.

It is for all of the above reasons that there is only one subwoofer in existence capable of integrating seamlessly into a high-end music system, allowing you to reap all of the benefits of having a subwoofer, with none of the drawbacks.

And the Vandersteen 2Wq is the one. And just in case you think I am a biased source, our correspondent Blaine Peck (who, for all you know is also a biased source) recently wrote the following, with no discussion between us about the topic prior to his sending us his comments.

Whether reproducing the plucked string of an acoustic bass or the sound of an analog synthesizer, the Vandersteen 2Wq subwoofer is a seamless extension of any system. Nothing else need be added! With its internal 300-watt power amplifier, it is the perfect compliment to any sound system. Designed to take on the characteristics of your main stereo amplifier, the amp in the 2Wq will not sound foreign in your system. Also, through an extension of the Vandersteen design philosophy, a unique gradually sloping crossover system is implemented so you simply do not know where your main speakers stop and the 2Wq begins.

Now that your main speaker/amplifier combination need not concern themselves with those power demanding low frequencies, they are freed up to work in a more comfortable range. Yes, now what is coming from your main speakers will sound better than ever.

The 2Wq is not just another subwoofer. It consists of three 8″ floor-facing drivers, each with a massive motor. So why not a more typical single 12″ or 15″ design? Well frankly, the mass of a larger driver will not allow it to respond as quickly as the Vandersteen 8″ drivers to today’s demanding recordings. The 2Wq’s 8″ drivers are designed to handle the content but be “fleet of foot” at the same time. Concerned about where to put them? You need not worry. With the control of both its respective level and the “q” (how loose or tight the low end is) you have the flexibility to place them in a location that fits your living environment and not sacrifice performance. The simple beauty of this product will soon become an addition to your room.

So whether on orchestral music, hard rock or something in between, the Vandersteen 2Wq will exceed your expectations...."
I don't think the subwoofer is the issue, but rather the interaction with the room. Just look at some REW waterfall plots. Subwoofers produce low frequencies and hence room modes. To cure this you need a larger room (because in a large room room modes occur at lower and hence less obnoxious frequencies), use multiple subs (two are often enough) to even out the response over a larger area, and use dsp room equalization such as the DSPeaker Antimode 8033.
At your budget I would get two SVS SB1000 subs plus an Antimode 8033. If your room is large I would save up for two SB2000 subs.
For some reading material, see here:
I agree with about 98.5% of what akg_ca just posted. The short version might be, pick a very good stereo speaker system that integrates a sub and amp into the design first. If you do not do this you must find an additional subwoofer/low bass system that is engineered very well, like Vandersteen, and pay top dollar to get that tight musical well integrated bass. Cheap subs will really make your musical experience worse....IMO.
I’m not advocating a separate sub rather than integral sub in the primary speaker design. Want only to comment about recent experience w/SVS. Have a pair of SVS SB1000s running with Silverline Prelude Pluses. The integration is seamless. A couple of tracks with intricate and agile bass work are on Andy Summers’ "The Last Dance of Mr. X".  Tony Levin's bass on Afro Blue & Footprints, for example, is very musical and fast. The image is very stable. The bass sound is absolutely not directional. It’s impossible to tell whether notes come from the sub or floor standers. They are suspended in space between the speakers. The SB1000 provides line level AND speaker level input. Not all their models offer speaker level input. Continuous Volume, Phase and Crossover adjustment make the subs very flexible.  The right channel sub did die a few (months?) after getting it. SVS provided a replacement very quickly. They might not have had good customer service in the past. My experience with them, however, has been excellent. They have responded to technical questions and dealt with the replacement issue. Their products have a 5 year warranty.  They provide a 45 day in home audition and pay freight both ways if you decide not to keep it.  If I had discretionary cash in abundance would love a pair of RELs - if only for the nice finish those have.  SVS is any color as long as it's black - matt black oak or piano gloss black (they might offer white too now). The "budget" finish look is my only complaint. Very happy with music produced by the Preludes supported by these subs.  Good luck with your decision.

Good to see Hsu Research mentioned. SVS is terrific. 

One not mentioned is Outlaw Audio. If you haven't already, you may want to check their subs out, especially if price point is a driving force.

I've had mixed results with subs. When done well, you will not know they exist until you remove them from the mix. Note that is subs with an s. 

Not sure if you want take the passive sub way. : )  Mentioning it as an option, since it hasn't come up.
Thanks Ghosthouse. I just want to be clear....I'm not unhappy with the bass, low end I have. In fact, I think it's great. I'm not purchasing because I feel something is "missing" more so at times I love really deep strong bass (I can turn sub off If I choose). Deep classical organ to EDM. My musical taste is varied. Coming from a subwoofer a few years back in my 2 channel system, it's really something I like and it "adds" to my listening experience. I was running 2.1 until we moved into a townhome about 10 years ago. We moved back into a house we purchased 4 years ago and I can now happily add a sub back into the mix. So yes, I love how balanced my system is now. In fact, it's the best I have heard except for a couple of other's systems I was able to listen. So while I appreciate the room advice etc( I have my room dialed in nice), I'm just wanting to induulge myself in to the world of heavy bass at times :)
Hi @aberyclark 
Okay, that's great.  You've done subs before so you know what's up with them.  They're a funny audio creature: "They are working best when you don't know they are working!"  Wasn't familiar with your Zu Omen Defs (apart from having heard of the Zu brand).   Just read a very favorable review of 'em on home theater  They appear to be very accommodating of a range of amplifiers and music types.  NOT trying to sell you on SVS at all, but did want to mention the relatively small size of the SB1000s was a positive for me.  

Yes ghosthouse SVS is probably where I am going. The RELs seem quite nice, however, They have a rep for being overpriced. REL did just kick off a Christmas sale. I will look thru my email
I've owned several SVS subs and think they are great for home theater. I wouldn't choose them for 2-channel. I prefer JL Audio. To my ears the JL Audio subs produce musical bass. 
I just put a JL E112 in with my new Vivid 1.5 speakers. I have them turned way down so you don't "hear" them, you just know that they are there. Very satisfied. I considered REL as well. Felt that the SVS was more of a home theater sub.
I also use the Zu Audio Omen Defs, I bought a SVS subwoofer a couple years ago a PB1000, on sale and a super low price. I had difficulty getting it to blend with the Zu speakers. I email SVS and receive a quick reply from the president of the company. Gary Yacoubian. He gave me his phone number and I gave him a call. I told him of my problem and he suggested I talk to the main engineer, so he patched me through to him.  After he listen to me describe my problem he gave me a few suggestions, after I implemented his suggestions I got the SVS dialed in for my two channel music. I thought that is real customer service.
I'm with @contuzzi @ricred1 @crwindy on the JL Audio. More musical.

But likely out of the OP's stated budget unless he/she can score a great deal used.

+1 regarding @crwindy 's post. Less is more. 

Since you seem to be leaning SVS, I second @yogiboy  's recommendation to go with the discontinued SB12 for $400. I'd double up. If you are going with one sub, then the Outlet PB-12Plus in Piano Gloss (with no damage) for $999 is another option.
A last thought on SVS (or any sub)...

Generally, ported’s okay for home theatre but sealed is better for music.
("generally" because there are probably exceptions)

I agree. I've had both. The ported sub was a bit "loose" or sloppy for music. Felt slow as well. Great for action movies where you want to feel the low rumble of a submarine, etc. The sealed unit sounded like more of an extension of the speaker woofer. 
I just bought a Fg rhythmik sub sealed for music , design for tubes amps.$950 it’s very very good, Sbayne Agon member replaced his rel for rhythmik..,easy to use, people there were very knowledgeable....
I believe jayctoy meant to say he bought a Rythmik F12G. The G designates the GR Research 12" paper cone driver, the aluminum-coned Rythmik version being named just F12. The aluminum-coned woofer is said to play louder than the paper-coned version before "breaking up", due to the greater stiffness of aluminum. Danny Richie of GR Research designed the paper-cone woofer because he feels paper has a more natural, organic timbre than aluminum, and that the paper's lower mass produces greater low-level resolution. When have you heard a sub talked about in those terms?! The Rythmik and GR Research subs are unusually good at music reproduction.
Post removed 

12-09-2017 12:14pm

"Do you guys have any suggestions for a good sub just for movies? Don't want to add stereo subs or a single sub for music..."


VANDERSTEEN makes two different subwoofer models: one with external crossover kit for 2-channel music  (V2Q) , and an AV/ HT unit with a LFE single cable input. (V2W)

For the V2W :  highly Recommended ..I have it along with a CASTLE CLASSIC ( a rebranded ATC sub)

In a direct A-B shootout at my home, it was a unanimous choice for the VANDY by all 4 listeners.

 If you know ATC, you know good they can be: they make them up to the $9K pricepoint for home use and multiples of that for commercial.

I wonder how many of you that are dissing or recommending other than REL have heard a REL Sub-Bass system properly set up in a good two-channel system with full-range loudspeakers?

RELs are not designed to work as fixes for speakers with poor bass response or with crossovers that alter the cutoff frequencies of the main speakers. They are designed to load the room and augment the bass response of the mains, therefore providing a lower and fuller low bass extension with more slam, as well as enhancing the soundstage size and sense of air around performers. Additionally, they can be used in out-of-phase mode to help alleviate room bass node issues.

AFAIK, they are the only sub system (other than the Sumiko knock-offs) that use a high-level signal from the amplifier’s outputs such that they see the same signal (and thus the upstream gear’s sound character) as the main speakers.

Although a few of the best "digital" subs outperform RELs in HT slam(movie explosions and such), nothing integrates better into a good two channel system than a REL unless it digitizes the signal and uses DSP to measure the room and alter the signal digitally. Even then, only the TOTL $$$ digitalizing subs better the RELs for seamless integration and positive sound enhancement of a two channel system.

REL has been around a very long time and there is a reason for that despite the higher price vs many newcomers...

Actually, many of the plate amps on Rythmik subs contain binding posts that take the output from a power amp (high-level signal), using the amp as it's source. The ones that don't are those that contain XLR inputs---the XLR2 and XLR3 model amps. Buyers are given the choice of plate amp models. All the Rythmik amps also contain RCA input jacks, for those preferring to use the low-level signal from a pre-amp as the source. 
Dave thanks for advice. RELs are still being considered. REL recommended the S3 or the T/9i for my set up
@aberyclark  back to the beginning, most music doesn't have both heavy and tuneful bass at the same time. Yes, there is plenty of music with heavy bass, example- blue man group, but is often electronic generated bass.  So the question becomes are you looking for chest thumping bass for this type of music ( for which ported will work fine) or loud and powerful bass guitar, bass drum and organ music ( as examples)in other words( tuneful bass). If it's tuneful bass, then high passing to the mains, digital bass management, willingness to relocate the sub to the best sounding location  and spending at least $1k or more are probably needed.  To test this out, buy the cheap Svs and then a sealed rel, rythmik, psa, to name a few and see if you notice a difference and then send the "loser" back. 
@dlcockrum  and @aberyclark 

Any thoughts on the Longbow wireless delivery system vs using the Speakon wired connector?
Hi David,

No experience with Longbow but it also gets its signal from the hi-level Speak-on cable from the amplifier's outputs and then transmits the signal wirelessly to compatible REL (their highest end) subs, so the benefit of the REL design should be retained. 

I can appreciate eliminating the constraint of the input cable for more flexible sub placement (although the sub's power cord could still be a possible constraint) but IMO it is a major oversight not to include a wireless remote function to adjust the sub from the listening position. Also, it is unclear if it can be used with multiple subs, but I can't see why not if both have a wireless receiver module.

I have a REL S5 and couldn’t be happier with it. When I purchased my REL a few months back I asked similar questions as you and considered the SVS as well. In the end I learned that one of a sub’s most important responsibilities in sound reproduction is to create a sense of space. The REL’s drivers are very fast and integrate seamlessly with my PSB T3’s and help to create an enormous and well integrated sound-stage. I love what it does with 2 channel music as well as movies. REL's philosophy and approach is a little different than other speaker manufacturers. I'd suggest going on Youtube and searching under REL subwoofer. Find a video where John Hunter, CEO and Chief Designer at REL talks about the REL philosophy. There are several very good ones.

Good luck with your purchase.
Rel makes fine subwoofers, no doubt. They also look good, but are relatively expensive.
For a while their unique selling point was that they connected at speaker level, and without a high pass filter for the main speakers. Hence their typical low pass crossover point had to be and was relatively low, with as little impact on the main speakers as possible.. These days, many other subs can do the same.
To be honest the sound quality of a sub is largely determined by the room. 'Speed' for example is an acoustic property and not as some seem to think a driver issue. Just look at REW waterfall graphs. Room modes are a nasty problem, only really solved by the combination of multiple subs and room eq.
Is there any advantage of a 12 inch woofer vs 10 inch? The Rel t/9i has a 10 inch woofer 300 watt amp. The SvS has a 12 inch woofer with 500 watt amp. 
The Sumiko's actually look like nice subs. Yes, they seem to be a REL copycat (Sumiko use to distribute REL).
In very broad terms the larger the driver,  the deeper it will go and the louder it will play without distorting. Conversely in very broad terms, the smaller the driver the more dextrous it will tend to be but will not go as deep. If you take a look at the entire REL line-up,  I believe they have 9 subwoofers total. 

Part of the REL philosophy is to find the subwoofer match for your speaker system and listening area. I'd suggest heading over to a shop that carries both SVS and REL and listen to them in a 2 channel system. 
Well i ordered the svs sb2000.  An audiophile friend I trust told me the SVS blends really nice with 2 channel and i should buy another if all goes well.  So we’ll see. Ill report back once up and running
Don't forget to treat yourself to an Antimode 8033 room eq as well.
Does the Antimode just control the EQ/DSP portion or does it adjust volume of sub as well? I'm thinking of picking one up at only $300 or so. From what I gather, I should set sub up as normal for best sound, THEN run the Antimode for auto eq, etc adjustments.
@aberyclark   Great on making the choice. I'd add a second sub when you are able to do so. 
I’ve been using a couple of RELs I bought used (About 200 bucks each) that were, and are, fabulous sounding (Had to make a grill for the forward firing Q150e which was easy since it had the frame, but the other is down firing). Maybe the Q series was made better or something, but the Q108 II and Q150e are available here and there used and utterly worth it. I tighten the screws once in a while, and made Canare cables for ’em with angled Neutrik plugs, and join the leads inside AQ spades at the amp to drive both subs from speaker posts. I'm a multiple sub (at least 2) advocate, but one will work fine.
Assuming this is about an Antimode 8033. It will only equalize automatically. You insert it in the signal chain, plug in the supplied microphone and then start the measurement. It will generate a series of loud successive sweeps from very low to somewhere around 200 Hz and after a few minutes you are all set (you can increase the listening area with multiple measurements of you want to). This is done with just the subwoofer - you leave the amplifier and the main speakers off. After that you turn on the amplifier and you can start adjusting the subwoofer level and crossover frequency. These you do manually and either by ear, or by measuring in REW, just like you would do without an Antimode.
There are two current models of the Antimode 8033, the Antimode Cinema and the AntimodeS-II. For most people the cheaper Cinema model is perfectly fine (forget its inappropriate name), also for use with multiple (mono) subs. Do read the manual first before you buy, to see if you really need the more expensive model (I didn’t). In my case I had to connect it at speaker level at the amplifier side and at line level at the sub side, using an attenuating cable from amplifer to Antimode.
The whole process will not take more than say half an hour, is absolutely dead easy, and only requires that you read the manual carefully.
I got the SVS hooked in and I really love it. I'm still going to do some fine tuning position wise. I have it 95% there but ran out of time yesterday. BTW, the SVS RCA cables seem to be well built and really nice (i purchased seperate)
I believe I have them dialed in about the best a single sub can do for my space. I am going to purchase a second in january/ I have it to where sound seems to lean to 53% left and 47% right (placed behind left speaker.). I set up with mono sources. Really, I could live with it. I would say a general listener would not notice.

I'm amazed how the sub really adds a presence to listening. For my taste, the bass should sound cozy and warm. The sub adds that along with some punch. You can really feel Neil Pearts bass drum and the moog bass pedal on Moving Pictures by RUSH. The heartbeat on Dark Side of the moon has a little tiny bit of stomp to it (which i like). For now I have it dialed in. I may do some more changing later on...but I really like the results thus far 
I added an REL S5 about a year ago to my Tidal Contriva Diacera SE speakers and that really improved the room bass but then I recently added an REL 212 SE ....and kept the S5 for the lt side of the room and now the whole presentation is magical.i will,at some point,replace the S5 with another 212SE but for now, all is of the REL VPs came over to help with the room positioning which save me a great deal of trial and error.
I have an older REL R 305 and its a nice sub.  I auditioned new speakers recently and paired it with an SVS and it was no slouch 
I have an S5 as well, and chose it over the 212 SE.
1. Recently I've been wondering how much I am missing with the S5 vs the 212 SE.
2. I'm thinking one of the upgrades this year is dual subs, similar to yours. 

Thank you in advance for any response... 
Calloway how do you you have your RELs connected through Neutrik? Which REL is connected to what speakers and where do you have them placed?