Tight bass sub recommendations


What are the recommendations for a high quality subwoofer set- up. I have Maggie’s 1.7I speakers which I love but I think could use a little sub energy. Most of what I have tested seems a little boomy. I know there are 2 schools of thought 1 sub or 2 subs. I’m just looking for a deep Tight bass. Thoughts???
schmitty1
Post removed 
I like Rythmik's servo designs.  They have a wide range of models for different budgets and needs.  Two (or more) subs are usually better than one, but you can definitely improve your listening experience with a single sub.
Vandy subs go well with Maggies.
B

My short answer is, two smaller subs instead of one bigger sub.

The following is my long answer.

Off and on over the course of a decade or so I tried building a sub that was "fast" enough to mate well with Maggies and Quads, on the theory that there might be a market for such. I built sealed boxes, low-tuned vented boxes, transmission lines (many different geometries), equalized dipoles, aperiodics, isobarics, and pretty much anything that seemed promising except for a full-sized horn. Some were better than others, but none passed the test.

The one day a really smart guy, Dr. Earl Geddes, taught me that the problem is room interaction, and regardless of how "tight" and "fast" a sub is, the room will impose large peaks and dips that will dominate its response. It is the peaks that are especially detrimental, in that they decay slower than the rest of the spectrum. His suggestion was to use four small subs asymmetrically distributed, such that each produces a different room-interaction peak-and-dip pattern, and the sum of the four dissimilar peak-and-dip patterns would be much smoother (and therefore much "faster") than any one alone.

This made sense to me. I was aware of an AES paper that showed a dipole has significantly smoother in-room bass than a monopole, and a dipole is two monopoles back-to-back with the polarity of one reversed, plus a path-length-induced time delay between them.

The general principle I learned from Earl is, the more intelligently-distributed bass sources within a room, the smoother the in-room bass. Two subs are potentially twice as smooth as one, and four subs are potentially twice as smooth as two. A dipolehas roughly twice as smooth in-room as a monopole in the bass region, so four intelligently-distributed monopole subs are theoretically comparable to two dipoles.

If you do a casual survey of relevant posts by Maggie and Quad owners, I think this is what you will find: Those who have tried a single sub usually go back to using no sub, and those who have tried two subs usually keep them in the system. I think this is because two subs exhibit less in-room smoothness discrepancy relative to a pair of dipole mains than does a single sub. So don’t fall into the trap of thinking "I’ll try one sub and if it’s an improvement then I’ll add another." One sub probably won’t be a worthwhile net improvement.

So to get back to your question, I believe two intelligently-positioned subs would be smoother (and therefore potentially "tighter") in-room than just one. Some EQ or other adjustability might be called for, because the amount of boundary reinforcement varies significantly from one room to another. If the two subs have continuously-variable phase controls, that might be sufficient adjustability: Set their phases 90 degrees apart to begin with, and adjust their relative phases from there (along with your adjustments of level and frequency).

I don’t mean to dismiss the qualitative differences between different subwoofer models, but I think the room-interaction advantage of two small subs intelligently distributed would probably outweigh the benefits that the single larger (more expensive) sub has to offer.

Duke

distributed multi-sub advocate

REL subs are the company you should be looking at. Their S Series subs are the best cost effective way to marry a speaker to a sub and not get anything but better everything from mids to low end out of it. This is using their special connections that take the amplifier outputs for the sound. This matches what is coming out of the speaker better. And REL is a super fast system, and can keep up with the speed of the speakers. Even Martin Logans will sound like the REL is part of the speaker system. I have to mention that 2 RELs are really the only way to fly, having one for each channel for true stereo separation and room filling balance. Be warned.... once you hear a properly setup REL dual sub setup..... you can't unhear it. It's worth every cent to get the S Series or better. REL.net..... Cheers
+1 for Rythmik.

The owner (who has a Ph.D in Electrical Engineering) also has written a good deal on how he achieves great performance:
http://www.rythmikaudio.com/technology.html

+1 for  the  VANDERSTEEN

Reposted article  provides a good summation of the conflicting strengths and warts in setting up a sub for music properly

http://ultrafi.com/why-everybody-needs-a-good-subwoofer/
August 3, 2008 by ultrafi in Tips, Tricks & Info | Comments Off on Why Everybody Needs a Good 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 subwooferto 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, Vandersteenhas 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 Vandersteen2Wq 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...."
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Another vote, Vandersteen.
With my Maggies I found if you keep the crossover point low and volume low you can get a half decent sound and rid of a lot of hangover even with a lower end sub.
I have been trying dozens of different high quality subs in my small room to try to find the best match with speakers like the smaller Maggies and Reference 3A monitors I have been using. My favorite by far for QUALITY bass has been the little Totem Kin subwoofer. It is -3db at 29 hz, and has the smallest footprint by far of all the subs I have tried (the enclosure is only 1/2 a cubic foot!) It uses a very rigid 8" carbon fiber driver in a sealed enclosure. For pure definition and completely uncolored bass that is fast and tight, this is the one. It bettered my previous favorite REL T-7i, in the way it actually improves the lower midrange of the music, as well as the detail in the bass. The other subs I tried got quite muddy in that area when I set the crossover much above 50 or 60 hz. If I set any of the other subs crossovers at 90hz or higher, they all did very negative things to the music. I can set the crossover on the Totem Kin sub anywhere between 120 and 200hz, and it does nothing but compliment the lower midrange and bass, making grand piano recordings and powerful brass horns sound more full bodied with no mud whatsoever, even in my small, often bass problematic room. I like the fact that turning the sub "on" does not make me first realize that the  bass is 10hz deeper or more powerful than without it, but that my midrange actually sounds better!  
People get too caught up on brands in these kind of threads. 

I mentioned Rythmik, but I also have Power Sound Audio and SVS and have owned HSU and others.  There are a number of other brands I'd be happy to own.

What's more important is getting the right sub for your space and intended use.  Nobody has asked what your room volume is, what your placement options are, whether you also would like to use it for home theater, etc.  Those things should drive your purchase decisions more than what brand you buy.

All of the brands I've mentioned have people that are easy to get a hold of and are very knowledgeable.  Of course they will recommend their products, but once you get an idea of what size/type/output you need, then you can comparison shop.  These are all internet direct, but you can do the same with your local dealer. 

Get advice about what you need, not what brand someone thinks is "best".  It's almost always the one they bought, which may not be the "best" for your situation.
@big greg, 
It isn;t the brand, but how the sub works with the speaker. Vandy's use an external crossover to cut off the speaker at low frequencies and letting the sub do its' job, so there is little overlap which would degrade sound quality.
It also relieves the amp from having to reproduce the lower frequencies, which are the most demanding.
B
Here's a very long explanation of why I like my 2 REL subs as they work very well. Wait...I meant a very SHORT explanation or, actually, none at all...they just sound inexplicably great, or at least I refuse to explic.
I went through this same scenario a couple years ago trying to find a sub to match up to the 1.7's.  Tried and returned a half dozen recommended subs (most mentioned here).  They all muddied the tone as the resonance of the sub would just last longer than the very fast and accurate Maggie's.  I happened to talk with an old timer at a local stereo shop and he mentioned that I should try a sealed, 8 or 10 inch sub.  He suggested a Martin Logan 700w as it was made to match up with their electro stats which are also very fast.  Hooked if up and "bang" I knew immediately that it was the right choice.  Great accuracy and speed with no laughing resonant tone.  The best thing about it is that I had tried subs in the 2 grand range with no luck.  The 700w?  $599.
The best yet, and that's saying something considering how high he's raised the bar-

Off and on over the course of a decade or so I tried building a sub that was "fast" enough to mate well with Maggies and Quads, on the theory that there might be a market for such. I built sealed boxes, low-tuned vented boxes, transmission lines (many different geometries), equalized dipoles, aperiodics, isobarics, and pretty much anything that seemed promising except for a full-sized horn. Some were better than others, but none passed the test.

The one day a really smart guy, Dr. Earl Geddes, taught me that the problem is room interaction, and regardless of how "tight" and "fast" a sub is, the room will impose large peaks and dips that will dominate its response. It is the peaks that are especially detrimental, in that they decay slower than the rest of the spectrum. His suggestion was to use four small subs asymmetrically distributed, such that each produces a different room-interaction peak-and-dip pattern, and the sum of the four dissimilar peak-and-dip patterns would be much smoother (and therefore much "faster") than any one alone.

This made sense to me. I was aware of an AES paper that showed a dipole has significantly smoother in-room bass than a monopole, and a dipole is two monopoles back-to-back with the polarity of one reversed, plus a path-length-induced time delay between them.

The general principle I learned from Earl is, the more intelligently-distributed bass sources within a room, the smoother the in-room bass. Two subs are potentially twice as smooth as one, and four subs are potentially twice as smooth as two. A dipolehas roughly twice as smooth in-room as a monopole in the bass region, so four intelligently-distributed monopole subs are theoretically comparable to two dipoles.

If you do a casual survey of relevant posts by Maggie and Quad owners, I think this is what you will find: Those who have tried a single sub usually go back to using no sub, and those who have tried two subs usually keep them in the system. I think this is because two subs exhibit less in-room smoothness discrepancy relative to a pair of dipole mains than does a single sub. So don’t fall into the trap of thinking "I’ll try one sub and if it’s an improvement then I’ll add another." One sub probably won’t be a worthwhile net improvement.

So to get back to your question, I believe two intelligently-positioned subs would be smoother (and therefore potentially "tighter") in-room than just one. Some EQ or other adjustability might be called for, because the amount of boundary reinforcement varies significantly from one room to another. If the two subs have continuously-variable phase controls, that might be sufficient adjustability: Set their phases 90 degrees apart to begin with, and adjust their relative phases from there (along with your adjustments of level and frequency).

I don’t mean to dismiss the qualitative differences between different subwoofer models, but I think the room-interaction advantage of two small subs intelligently distributed would probably outweigh the benefits that the single larger (more expensive) sub has to offer.

Duke

distributed multi-sub advocate


I tried a lot of these same things over the years, only instead of persevering l eventually just kind of threw up my hands in exasperation. Before that though I did build a transmission line, tried different subs, in all kinds of locations, and rooms, and it was a..... Total waste of time.

Well not quite. I did learn one thing. I learned you CANNOT achieve great bass with just one, or even two subs. Can. Not.

Sorry, Vandersteeners. Tough luck RELics. Its not you. Its physics.

But the one thing I did not do, the one thing I never saw or even heard of anyone doing until recently, was try a whole bunch (four) of small (10" is plenty) subs located around the room. Asymmetrically! And even sometimes out of phase!

This idea is so out of the box original and totally different than the reigning paradigm it deserves a Monty Python "and now for something completely different" introduction.

Although actually it feels more like something out of the Twilight Zone: At the signpost up ahead, people pretending nothing just happened.

When it did.

Puzzling strange. But, oh well. Thanks, Duke. I get it. UPS is on track to deliver four drivers, four cabinets, and two amps Monday. Got a few weeks of work ahead of me but then I should finally be able to get me some genuine audiophile quality bass in my room.

We now return you to your regularly scheduled comments.
@gdnrbob I wasn't referring to you specifically, just making a generalization.  I'm also a photographer, and the same thing happens when someone decides to take up that hobby.

Q "What camera should I buy?"

A "Nikon/Canon/Sony/etc. (whatever I own) is the best!"

Your response was more on point, mentioning a specific feature that might be of benefit to the OP's system. 
@big greg, 
No problem.
@millercarbon,
I have no doubt 'The Swarm' works well, but it just makes sense that multiple subs will nullify/even out room nodes. Any of the subs listed would do that, when 4 or more were hooked up. 
The problem is who has that much space? Not all of us have a dedicated listening room.
B
2 REL S3s compliment my Martin Logan Montis.

Montis is run by a Krell KSA-200s. OMG
I have 2 more REL S3s put away for the 4 subwoofers effect. It can wait. My family is being kind as it is. Got them at a steal of a price. One day!!

Thank you millercarbon for your kind words.

Gdnrbob made an insightful observation: "...it just makes sense that multiple subs will nullify/even out room nodes. Any of the subs listed would do that, when 4 or more were hooked up."

Yup. That’s why I don’t claim that my four small subs are the one and only way to do it. For example Millercarbon is building his own four-sub system, using a better woofer than the one I use.

And the subs don’t have to be identical either. So you can start with what you have and add on.

Duke

That's the beauty of the Swarm approach. Because room reinforcement characteristics are so dominant, which sub matters much less than their number, location, and phase. And my understanding is, pretty much in that order. In other words four of just about anything beats one of just about anything. Especially if the four are optimally located, powered and phased. Might be a bit of an exaggeration or over generalization but this crowd being such a hard sell its warranted.

My set will use the same four 10" drivers, but in two different enclosures- two sealed and two ported. Plugging a port converts a cab into a sealed enclosure, making for three optional configurations. Together with placement and phase that is a huge amount of tuning flexibility and control!

The vast majority still do not appreciate what a game-changer this is. Which is good- I have a Talon Roc sub to sell! Depending on what that goes for this may turn out to be one of the most cost-effective upgrades ever!




color me fanboy but 2 built in subs and 11 bands of analog and variable Q and I have killer audiophile bass right at my listening position....and ha, IF I want to add two more I can....

and the transfer function function of my main amp shapes the whole shebang....

let me see..great  bass everywhere but no stereo image in that far left corner......yep, guess I should retreat to bose 901.....
the real power of a fantastically executed sub is threefold...

take the strain off the 80-100 hz and up drivers

power correct the amp driving the variable EQ and Q ( duh ) sub

optimize the high pass amp because it now nolonger deals with nasty back emf, etc....

your results may vary....

@millercarbon, one thing to be aware of is that there may be more to the difference between a given company’s sealed and ported subs than the sealed or ported enclosure itself. Rythmik Audio offers subs with either a 15" or 18" woofer in both a sealed and ported enclosure, and using the provided foam plugs to block the ports in the ported model does NOT, according to Rythmik design engineer/owner Brian Ding, make them identical (for reasons explained by Ding in the technical pages of the company’s website). Interestingly, his subs using 8" or 12" woofers are offered as sealed designs only, not ported.

Highly technical details on all aspects of sub design are provided on the Rythmik Audio website. Well worth reading, even if you elect to get a sub or four from a different company. Speaking of four subs (a real good idea), as Duke said a swarm can be created from any group of subs, four identical ones perhaps easiest to optimize in a room (for reasons, again, explained by Ding). Another subject covered by Ding is that of mixing sealed and ported subs in a room. Though he recommends not doing it (again explaining why), for anyone insisting on doing so he provides the information necessary to do it correctly. The plate amps on the Rythmik subs include controls to aid in that endeavor, including continuously-variable phase and 3-position damping.

Very interesting reading regarding subs and the various approaches to consider.
I’m just looking for a deep Tight bass. Thoughts???
'Tight bass' is a thing that does not seem to exist in nature. Its an artifact of over-damped speakers in a hifi setup.
I highly recommend Monitor Audio Silver SW12 subwoofer.  For the simple reason the room correction microphone and 32 bit digital processor, which solves all of the room node problems and is the best implementation of a sub-woofer amplifier crossover I have ever experienced.  I use JM Labs Mini Utopia's, which are notoriously hard to match with a sub due to there speed and transparency.   This is a match made in heaven.   Other features include HYPEX 500 watt Class D amp and massive magnet structure on a Aluminum/Magnesium ceramic coated woofer.   Check this sub out before you buy anything else.

@millercarbon, one thing to be aware of is that there may be more to the difference between a given company’s sealed and ported subs than the sealed or ported enclosure itself. Rythmik Audio offers subs with either a 15" or 18" woofer in both a sealed and ported enclosure, and using the provided foam plugs to block the ports in the ported model does NOT, according to Rythmik design engineer/owner Brian Ding, make them identical (for reasons explained by Ding in the technical pages of the company’s website). Interestingly, his subs using 8" or 12" woofers are offered as sealed designs only, not ported.

Highly technical details on all aspects of sub design are provided on the Rythmik Audio website. Well worth reading, even if you elect to get a sub or four from a different company. Speaking of four subs (a real good idea), as Duke said a swarm can be created from any group of subs, four identical ones perhaps easiest to optimize in a room (for reasons, again, explained by Ding). Another subject covered by Ding is that of mixing sealed and ported subs in a room. Though he recommends not doing it (again explaining why), for anyone insisting on doing so he provides the information necessary to do it correctly. The plate amps on the Rythmik subs include controls to aid in that endeavor, including continuously-variable phase and 3-position damping.

Right. I'm dealing with 4 identical drivers. Two will go in sealed cabs, two in ported. The two ported are larger, because porting calls for more volume.

The point of plugging a port is not to make the ported speaker identical to the sealed one, but merely to alter its output curve. Porting results in a curve that extends flat response a little lower than sealed, but at the cost of output that drops very steeply once it does begin to drop. Sealed begins to roll off quite a bit higher in frequency but at a much lower rate. 

Plugging a port won't make the ported speaker identical to the sealed one. It will however make it identical to a sealed enclosure of the same volume. That's the key. There's theory, and then there's practice. Or as a great philosopher once said, "Everybody has a plan until they get punched in the 

In practice what happens is plugging a port will cause that speakers output to begin to fall off at a higher frequency. So you got a little too much mid-bass, you plug one port. Still too much plug another.

Also keep in mind this is just one of several ways of getting beautiful flat low bass when using the multiple distributed or Swarm subwoofer system. 1. The location of each of the four subs. 2. Ported or Sealed or plugged port. 3. Phase (one or more can be wired out of phase). 4. Phase Quadrature (Continuously variable, per pair). 5. EQ.

The ground work has been laid. Now comes the work of getting it done.


Tight bass can be created by a bass player damping every note, and utilizing over-damped drums. Listen to this sort of thing outside with no acoustic boundaries and there ya go!

I've accompanied both electric and acoustic basses (with and without a pickup going to an amp), and reproducing an acoustic is a more demanding task that reproducing an electric. Most speakers and subs---and most importantly, rooms!, to one degree or another, add a little "plumpness" to the sound of an acoustic. An upright bass, played purely acoustically, sounds more like a cello than an electric bass, just playing lower notes. I got to intimately know the sound of a cello from my sister practicing hers at home.

Some of my favorite electric bassists play sometimes using the heel of their right hand (if right-handed) to mute the string, in effect making the electric bass sound more like an acoustic. Listen to Joey Spampinato of NRBQ to hear what I'm talking about. Keith Richards loves his playing, enlisting him for the band he put together for his Chuck Berry documentary, and offering him the bassist slot in The Stones when Bill Wyman left. Joey turned down the offer, electing to remain with NRBQ, a much better band.

REL is a sonic match.
If the sub can't correct for the room then you will have plumpyier bass and it will not sound as if its coming from the main speakers.  Which should be the altimate goal.   
As for Rel good subs but not necessarily a sonic match to every speaker and room.  
+1 for Rythmik

Owned various REL, Velodyne, ML, Revel, SVS, Infinity, B&W, Wharfdale, Sunfire, plus others I don't care to remember...  an MBL too....   Only Wilson impress more but doesn't like that price tag.  I like JL too but matching it seamlessly is very hard.
I use a Klipsch sw308 sub with a pair of Kef ls50s. Great combo. I can highly recommend this sub for very articulate, tight extended bass. It uses two 8" passive radiators in conjunction with its 8" bass driver to do the deed very well indeed but in a more compact package than most.
Does the op have a budget or any room/layout constraints?
martin logan dynamo is a really fast, tight sub which should pair well with the maggies--very good value used.
Hey Shcmitty1 I have my 1.7i's for 4 years and have worked on various ways to improve bass with most of the suggestions posted here. The problem is the Maggie's produce such a clean it's hard to integrated a sub without smearing the existing sounds. My last addition is a 1000 want parasound 21+ and a slight increase in volume. They are so power hungry and sing when feed. I would like to hear from more Maggie owner being this was the question you posed. Thanks
Tight bass can be created by a bass player damping every note, and utilizing over-damped drums. Listen to this sort of thing outside with no acoustic boundaries and there ya go!
I've been playing bass since 6th grade. True- it gets a lot more percussive played that way. But impact is one thing- tight bass is another. If the bass is right, its got impact **and** definition. If its tight bass, its got punch but the impact is insufficient and no definition- you keep trying to turn it up to get it to satisfy. Now I might be harder to satisfy because I've played bass so long; in my band right now I play keyboards and keys are more capable of making unnatural bass notes, but even there, the sound is usually a combination of what the player hears in tandem with whatever speaker he uses to play the keys with. But if I'm playing in a club, even when playing such bass, its anything but 'tight'. The speakers are interacting with the room...
I have extensively demo'ed the JL Audio D108 sealed sub and it is extremely tight and musical.  The 8" driver is fast and agile with no bloat or boom.  Covers the upper sub-bass quite well, better than larger diameter subwoofers.  Depending on room size (1) would be fine, (2) better.  
You sacrifice some of the deepest frequency theatrics but gain some upper bass punch and integration- sounds exactly like your goals.  
Wait- so you're saying bigger room more subs? How big until you need 2? Three? Four???
Another vote for JL Audio. Owner of two E110’s here. I honestly can’t see how anyone couldn’t like these subs.
I would recommend that you take a listen to the newest iteration of the MartinLogan Dynamo subs.  I am using a pair of the Dynamo 1100X's with my Magneplanar 3.7i's and they integrate very well.  They have the advantage of Anthem Room Correction built in.  As well, all of the settings can be changed from the listening position with an app that will run on an iOS or Android device.  In my system the Dynamos replaced a pair of REL T-9's.

LarryRS
I'm happy with using just one B&W ASW825,  which has an ultra-rigid. Rohacell® sandwich cone at 12 inches.  At one point,  I had 2 of them,  but ended up deciding to use the second one for my little recording studio and just one for my stereo.  It's a non-ported design and sounds nice and tight,  much quicker than it's bigger brother,  the ASW855,  which uses a 15" driver.
bwgroupsupport.com/downloads/specsheets/bw/ASW825%20InfoSheet.pdf
I have Magnapan 3.7s.  I use two REL G2.  Great match.  The REL was the first sub I had heard that has the speed to work with panels.  
Just my $0.02
Find some good ENTEC subwoofers, preferably refurbished. 
If you are looking to keep your 1.7i for a while then I would concur with those who suggest making the investment in a pair of RELs.

It will not only deliver clean tight bass, it will also enhance your overall lower mid range by revealing more depth and texture within  your sound stage. 

I was looking to invest in a new pair of speakers a few years ago. I changed my view on how I was looking to achieve my goal of obtaining better sound. It was then that I realized that I could better than accomplish my goals if I invested in a pair of Subs. 

I looked at JL as well but found that the Rels were more Musical - especially using the  Neutrik SpeakOn connectors at the High Level input to the sub bass system. Although REL makes these cables, Three are a couple of other companies that make upgraded versions. 

I still have my Speakers and REL's and have no plans on upgrades..

If you go on the website there is a speaker - sub pairing section. They recommend the T-9I for your 1.7I.

Good Luck

Speaking of my favorite... REL S Series subs. There is a limited edition one with the driver from the G Series installed inside the REL S5 cabinet and more. It just received a WOW from Tone Audio. Tone Audio uses a pair of the REL S Series 212SEs as their sub of choice for their system since reviewing them. The REL 212SE is like having 2 REL S5s stacked on top of each other.
Anyway...... This review of the REL Carbon Limited gives you more insight into why some of us audiophiles find no other choice for a subwoofer (pair needed) than REL. It's the "REL EFFECT"
Here is the link...... http://www.tonepublications.com/review/the-rel-carbon-limited-subwoofer/