Honest Experience on Effects of Subwoofer Please

["mijostyn: Since I build my own subwoofers in a rather extravagant shop I have the capability to do things others can not."]

Rather extravagant?! I'm guilty of tool envy and you have some great choices. It's your space-iousness! Dust collection, lighting, running water, and what looks to be warm and cosy in the winter? Dude, you got it going on!

You take care of the dust from those exotic woods. Enjoy.

@kingharold , now imagine 8 of those in one room.

Since I build my own subwoofers in a rather extravagant shop I have the capability to do things others can not. Still, there are some excellent subwoofer kits available and many SOTA drivers available. These are not that difficult to build and can save you piles of money.

This really is not that complicated. A sub enclosure has to be extremely stiff, heavy and non resonant. With DSP and room control porting has become a thing of the past. You limit your low end extension that way. The only other spec that matters is the volume of the enclosure but even if you are off a little, a powerful amp and DSP have you covered. With an outboard crossover you can use passive subs and separate amps. I personally do not like amps in speakers. You can easily do a 4 woofer system for the price of two commercial powered subs if not less. Making a subwoofer look good is the hard part. I tell people to cover them with equipment carpet if they do not have finish facilities. 

With a symmetrical sub array and accurate phase and time alignment you shoot yourself in the foot not taking the crossover up to at least 100 Hz. I ran 125 Hz with my old speakers. With the subs digitally matched you would never know they were there until you turned the volume up too high. A good test is, you should be able to switch the woofers in an out and not hear any difference on a Peter, Paul and Mary album played at moderate volume 80-85 dB.  Anything with a bass drum will immediately announce the subwoofers.  Paradoxically if you use just a low pass  filter at 40 Hz there won't be any difference either but the end results are night and day. 

I'm listening to Shostakovich's 10th at this moment at only 73 dB and the bass drum is rolling off me like an ocean wave even at this low volume.  

AKG_C wrote, "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."

I have not found that to be the case with my Bill Fitzmaurice designed HT Tuba folded corner horn subs.  With a sensitivity of 104 or 105 db/w/m depending on the 15 inch driver used a modest amplifier can produce all the clean, tight  bass the music requires.  The only downside is the size of eighteen cubic ft. each. 

@mijostyn --

Well put. 

@lonemountain --

Ad 1). Don't see how that applies here. If subs are successfully implemented I'd only want them to reflect the variation in source material. It's about what becomes your "axis mundi" for setting the reference gain, and the rest really falls into place from here in my experience. 

Ad 2). Sure, below the Schroeder frequency the resonating nature of sound waves becomes an important factor with regard to placement and how to avoid the most severe nulls and peaks. It can be a balancing act using both digital bass management and a more pure acoustical approach of placement and sub numbers. In my dual sub setup with a higher cross-over between the subs and mains, symmetry of placement is paramount, and corner loading, while not always ideal acoustically, lends itself naturally both with regard to proximity and symmetry to the mains, while also taking advantage of boundary gain. I could successfully add two more subs for an even smoother acoustical response, but that's for future plans to come.

Ad 3).

I'm guessing this is the potential rub many are confronted with here; leaving the mains running full-range and then trying to blend in subs (slightly overlapping or not) is really dealing with two separate systems - with all that entails. 

I can understand some of the reasoning behind why many wouldn't want to employ a high-pass filter digitally over their passively configured main speakers, hereby adding another filter layer - albeit a sonically more transparent one compared to passive filters, to my ears - to an existing passive one, which is where I would suggest a more radical approach; without a HP running the mains full-range can integrate quite well with subs (I've used such a configuration years back), but my current approach high-passing the mains is done fully actively with a digital XO sans any passive cross-over, and as such is really dealt with as a 3-way system with the subs in close proximity to the mains. Every cross-over section, especially where horns are used, involves dealing with delay elaborately and eventually fine-tuned by ear, so the high-passing part of the mid-woofers is no different an aspect than high-passing the compression driver above them - or the subs for that matter just below the knee (i.e.: tune) to protect the drivers due to unloading. This is the radical nature I'm referring to above, because it's done considering the system incl. the (sub-)bass section as a whole.   

Implemented as such remember the mid-woofers will be relieved of LF which, certainly when HP'ed above 70-80Hz, equates into a cleaner presentation and bigger headroom - up to 10dB's, even. That's significant and audible for the better when carefully implemented. 

Ad 4). Why not take the next step and make it multiple larger subs?

Ad 5). I rarely encounter high-pass filters between subs and mains higher than ~125Hz. In my own setup the high-pass is set just below 85Hz, which is dictated by the upper end response of my tapped horns. I try to avoid extensive EQ'ing, but I guess I could stretch that HP a bit more towards 100Hz with some minor corrections.  

Ad 6). It's delay settings galore on my Xilica DSP. 

Ad 7). Using the ears is always the last measure here. 

Ad 8). You still hear the half and quarter waves of a 20Hz tone in moderately sized listening room, albeit with lesser clarity vs. the full wavelength due to room interaction. 20-25Hz in not in vain by any measure in my moderately sized listening space.  

I think the issue with subs is its far more complex than it appears:

1) SOURCE MATERIAL has varying bass levels. The deep bass in source material is all over the place, and its not your fault.  It's not consistent at all and we find a large variance in quality.  Many records, especially old english records have no bass (Genesis, Selling England by the Pound, Kate Bush, etc).  Many streaming services strip bass out to prevent clipping within their processors.  If you adjusted your sub to sound good on one thing, the next thing will likely be very different.  This makes one think its the sub not working correctly when its no such thing.   

Conversely, if you set up your sub to sound good on Eminem, very little has that much bass in it.  Technically, this is where recording quality has improved dramatically over the years but old recordings or some broadcast mediums roll the bass off tremendously.  

So the music you play may determine if you say "my subs don't do anything".. 

2) SUB LOCATION in the room is also greatly varied compared to someone else.  Since most of us are horrible about setting up subs in room, or we love to use just one-in the dead center between two speakers (the single WORST place) - we get vastly varying results of a given model of sub in the room.  Quite often this center position is the null point in the room and the owner never tries a different place because he or she has been told or mistakenly believes "they belong there".    

3) Use of HIGH PASS FILTERS in line with mains is very audible, introduces a major phase shift due to the larger physical distance between mains and sub, and almost never sounds good.   Using mains full range and subs low passed and then blending to taste is my preferred way, getting the subs as close as possible to the mains, maybe even on the same stand (if you are using sound anchors).  I've heard and set up many systems where this technique makes the subs almost 100% undetectable.  Not always, but certainly better than HP inline with an expensive speaker I bought for "resolution". 

4)   The idea of one big sub is not the best way.  The best plan is the opposite, multiple small subs set up on multiple different walls at different distances from corners.  This is far more likely to yield a smooth response in the room.  That's why I like Duke Swarm idea, it works. We use multiple subs in pro studios all the time, it always works better to excite more room modes rather than fewer room modes.  Then, one mode doesn't dominate.

5) Use subs somewhere from 125 Hz to 95hz on down works better than trying to get subs to work up higher.  It might work in Live sound, but not for home.   

6) Make sure you have inverted phase on the sub to see if its better.

7) do not depend on measurement with a low cost or built in system.  Those little mics that comes with receivers or lower end preamps are absolutely terrible- they have no bass, they are not accurate below 200Hz 99% of the time. 

8) People expect there to be bass in small room.  Bass wavelengths are long, and if the frequency's wave is longer than your room dimension guess what, you won't be able to hear it.  (32Hz = 38 feet long wave.  Anything room dimension shorter than this means you cannot propagate (reproduce) 32Hz in there.  20Hz wave = 54 feet.  10 feet means 60Hz is about the best you can do.

Brad

As a last comment, I previously mentioned 8 subs. What I plan on doing is 8 drivers in 4 enclosures.  I'm doing this because in comparison to live performance I feel my bass which is wonderful for a home system, needs just a little more authority. Doubling the drivers only gives you another 3 dB but I think the array will pressurize the room better for lack of better terminology. It may not work. The problem might be with the dynamic range of the source material. It will definitely lower distortion in the bass so it should be worthwhile in the end.   

@mijostyn

So you aren`t running the mains full range then right ? Are you using a high/low pass filter on one of the subs ? By stereo array are you running L&R to each sub ?High level ?

I have 3 musical subs...

2 - HSU ULS-15 MKII`s and a Revel Ultima 15 all sealed. 

@b_limo , that is an interesting way to do it. What are you doing to delay the sub so the arrival time and phase are the same as the main speaker's Your version is surely visceral when you are seated but everywhere else not so hot. The realistic way to do it is multiple subs out front and a lot of power. 

@scm , I also cross over at 100 Hz. You need subs that sound good that high and they have to be in a stereo array. The rational for it is to take the load off the main amp and speakers to lower distortion and increase head room. In my case IMHO it is critical. I use full range ESLs. One diaphragm handles everything. Taking out the bass literally cleans up everything and they play louder than anyone could stand for 30 seconds. 

@phusis 1+. Live concerts are in much larger venues than a residential room. Bass is much less of a problem in larger venues. Then you have to deal with echoes which can be profound. We really do not have echoes in our homes or rather very little. The distances are too short which makes the delay shorter. We have difficulty with reflections which can be perceived as part of the music then as a distortion of the original signal. 

There are very few systems that could not benefit from subwoofers. My goal is to save people, who want to get into them, time and maybe some aggravation. I have always used a two way crossover, always, right from the beginning. I had a single sub for 6 months when I discovered that one was not going to do it. This lasted for 22 years and as I said before it was a love/hate relationship and at times very frustrating. 22 years later TacT entered the market and I jumped right one, their 1st preamp and I upgraded to another one down the line. The results floored me. Then I realized that I needed 4 subwoofers, next is 8. The TacTs time has come to an end as there is now better tech out there. I thought I was going to get a Trinnov unit but I am waiting to see what the next high end DEQX unit is going to like. It is supposed to be released next quarter. The company has not yet released an owners manual so I can get a handle on it's capability. But, from the outside it looks great.

The point of all this is that if you start out with two subs and a digital crossover like the MiniDSP you will saving yourself a lot of time, frustration and expense. Don't do it cheap. Do it right. On the other hand if you have to learn the hard way like I did fire away. You will learn a lot in the end.

Subwoofers have made my system come alive like never before. I recently purchased the latest iteration of KEF R3 speakers as a space saving exercise, having eschewed floor standing speakers for the first time in decades. I placed the stand mount-sized R3s atop my Martin Logan 12" powered subs creating what amounts to a 4-way system with bass extension to 22Hz with the crossover point set to 30Hz so as not to muck up the lovely mid-bass produced by the KEFs right out of the box, with the subs processed with the subwoofers' built-in ARC Genesis room correction by Anthem. The 600W RMS Martin Logan Dynamo 1100X 12" subwoofer is an excellent value. In fact, I am toldf that ML subs are the manufacturer's best selling product category. Retail list is 1299.00 USD but they are offered at a reduced price periodically.

@b_limo 

When you say 100Hz is that where you have your sub crossover set to ?

Nope QLN Sonoras. With dual REL Tzeros sounds fantastic. Dialing it all in was cake. Read a few articles and watch a few videos it take a little fiddle farting but is well worth it.

What do you do if you have speakers ( Goldenear Triton 1) with built in powered subs?

@music_is_life --

SUbs are easy to set up. 

That's just rallying for your position. To some it may be, out of luck or other, but it's certainly not a default outcome. In any case: however high the bar is set may be the achievement one sees fit. 

SUbs are easy to set up. 

@wolf_garcia --

A lot of silliness get passed around with topics like this one, and all bloviating aside, subs aren't that difficult to set up, more than one helps tame standing waves but one sounds much better than none, and don't be afraid to try 'em. I have a few older RELs (no high pass nonsense needed) bought used and they're great. 

...

.. I have decades of experience in studios and live concerts as a musician and live sound mixer, and am baffled by how baffled some are with this stuff, and the noted complexity some need to yammer about doesn't help anybody.

On the second paragraph: you may have given yourself the answer without realizing it; not everybody has "decades of experience in studios and live concerts as a musician and live sound mixer," which otherwise would've likely given them a head start implementing subs in the home setup. 

Re: first paragraph: it's not really about "complexity," but rather what you choose to go with and how you intend to do it. Being very experienced yourself with sound mixing both in studios and at a live concert milieu while having a bunch of REL's (whether they're used or new is besides the point, btw) to play around with, isn't a bad outset by any means. REL's would seem easier to implement in an existing setup compared to other sub brands, and combined with your experience in the field you're dealt a good hand here. I'd say that's not necessarily representative of most who're about to go the sub(s) route?

I wouldn't discourage anyone from throwing themselves into sub(s) usage, but I would like to tell them of a way to implement subs that deviates from small, inefficient cubes augmenting main speakers run fall range. High-passing the main speakers isn't "nonsense" but can have obvious advantages, and going with big, higher eff. subs in more numbers than one lends further, potential advantages to boot. Where it might get more complex is going active, but who says everything comes with the snap of your fingers?

Going even further with DSP's and perhaps bass management (as outlined by poster @mijostyn above) can add to integrational bliss, and so while very good results can be had without bending backwards per the more typical or popular way to integrate subs, it is to some a mere starting point going way back in their subs voyage. 

It's like hitting someone on the head for going other ways, god forbid with the intention to raise the bar perhaps even further. It's not bloviating or arrogance, but simply sharing experience others might appreciate exploring for themselves. Make of it what you will. 

["ryder: The only thing I don’t like about the REL is the price, particularly the current price increase of the S-series without any changes to the models."]

A friend dropped by with his new $9K Studio III REL to compare. He returned it that afternoon and later purchased two processing subs with a few hundred left over. The real wood finish on that REL was stunning, no chrome bits though. 

REL headquartered in Berkeley CA. My State will get an almost 10% cut, sweet! Enjoy.

"Subs are easy for me to set up (sorry mijostyn) as they’re a relatively simple thing. You turn ’em on and listen...mine have phase switches that need to be heeded and some may find that daunting but really...you simply listen. "

I agree with wolfgarcia. Turn em on and listen. Hopefully any sub you purchase today will have an app to allow you to change all sorts of parameter from your listening position, from volume to phase to cutoff frequencies, etc. In the old days you had to get up and change at the sub.  A remote app is a game changer with respect to setting up a sub.  

One of the best features of the Rythmik Audio line of subs is the phase control included in their plate amps. It is not a phase "switch" (either zero degrees or 180 degrees), but a continuously-variable phase/delay control knob, adjustable from zero degrees/zero delay to 180 degrees/16ms delay, and anywhere in between.

First find a reasonably good sub location with relatively low mode problems (both nulls or peaks), then use the Rythmik phase control to maximize the phase relationship between sub(s) and loudspeakers. Everyone talks about the long wavelengths of bass tones making phase relationships below, say, 100Hz, mute is ignoring the fact that if the outputs of sub and loudspeaker don’t create a combined flat response at the cross-over frequency (if they are not in phase), there will be a hole in the frequency response created. Loudspeaker designers have to do the exact same thing in the blending of tweeters with midrange/woofer drivers.

I have a small room, with a line array of Rel s-510’s.  The overall improvement is off the charts:  soundstage, mids, hi’s are all much improved, not to mention of course, the low end.  I started with one, then a second, then two more, and finally, a third pair.  The improvement at each step was immediately noticeable, and not incremental.  Individual instruments have more weight and solidity and the music has a live concert-like low end foundation.  My two cents!

Subs are easy for me to set up (sorry mijostyn) as they're a relatively simple thing. You turn 'em on and listen...mine have phase switches that need to be heeded and some may find that daunting but really...you simply listen. Adjust the levels, again...simple. I have decades of experience in studios and live concerts as a musician and live sound mixer, and am baffled by how baffled some are with this stuff, and the noted complexity some need to yammer about doesn't help anybody.

I appreciate all the useful advice and opinions. I’ll just keep this short and avoid being long-winded.

I have been reading a lot. I understand all subs SVS, REL, Rythmik, Arendal etc. have their own pros and cons and fans, and it’s all good. It is highly likely I’ll end up with a REL S series. Although other subwoofers may offer better performance for the money, the real deal breaker with these subs for me, is aesthetics. I find the looks of most subs to be undesirable. The REL looks classier and more elegant with a clean shape, curved edges and gloss finish.

I also understand two subs work better than one but due to the current space and budget, I can only do one.

M-db, current placement of the sub may not be optimal but that’s the location where the sub produces the best result with the most even and non-boomy bass. Corner placement close to wall boundaries produced the worst result.

The only thing I don’t like about the REL is the price, particularly the current price increase of the S-series without any changes to the models.

ryder, whatever jon_5912 is referring to as "upper bass" there have been a few subwoofers available for almost two decades that have the ability to adjust and remotely control parameters in the 100Hz or higher region. The open skinny string G2 on my Double Bass is tuned to 98Hz which is similar to the middle frequencies of a typical drum kit. 

It sounds like for the past 18 or so years you've been using a sub equipped with basic crossover, phase, and volume set-it and forget-it? To enjoy recordings up through the 60's as well as modern recordings were many producers are steeped in compression I find requires an interactive subwoofer system. Audio fun! 

+1 mijostyn & b_limo... I'm quite confident you would experience that appreciable difference using remote controlled processing subwoofer/s that offered listening position remote control of their parameters and customizable presets.

You mention proper setup. If that's your subwoofer shown just inside your left speaker in your system photos (which could very well be controlled by a processing sub). I'm equally confident that may not be the optimum subwoofer location. Your sub placed on your listening position and playing a low frequency test tone then a stroll around your room should reveal your rooms loudest modes (sub locations). Map them out. All the best.

I cross my mains over at 100hz.  I have an SVS Ultra 13, 155 pound behemothof a sub 12” behind my listening seat.  I can feel kick drums in my chest and even throat.  Music has become visceral.  My stereo can pound you into submission.  It makes grown men giggle.  Its good

Wolf,

Thank you for the rare glimpse of common sense on an audio forum. People make so much of this stuff harder than it really is. IMO, it’s so they can feel really smart for solving the (usually non-existent) problem.

@wolf_garcia, I hate to be a PITA (not really) but, if you think subs are easy to set up then you have not heard them done correctly. 

@phusis , When enough audiophiles hear subwoofers set up correctly, digital cross overs and all, the acceptance will grow like a snowball rolling down hill. All my audiophile buddies on hearing my system got subwoofers and digital crossovers with room correction. None of them are dyed in the wool analog guys but still.

It turns out that with the proper equipment subs are easy to set up. The computer does it for you. It measures your system one speaker at a time and adjusts delays and volumes appropriately. The only thing you have to do is select a crossover point and slope. The system I use now lets me change crossovers and slopes on the fly while I am listening which is very helpful. 

A lot of silliness get passed around with topics like this one, and all bloviating aside, subs aren't that difficult to set up, more than one helps tame standing waves but one sounds much better than none, and don't be afraid to try 'em. I have a few older RELs (no high pass nonsense needed) bought used and they're great. 

@mijostyn --

+1

Many a sub(s) implementation appear strikingly meager, malnourished and of secondary consideration in its overall implementation. I'm guessing it's that mentality again; why have a couple or further multitude of (sub-)bass behemoths lying around in the listening space when you can have all but one the size of a small cathouse?

Because it isn't only about extension, but rather, as you so rightly point out, it's also and not least about the added sensation of power and effortlessness of presentation to instill that live feel of music, including the contribution from the main speakers here when properly high-passed.

And yet, what is it about "hi-fi" that very generally turns its back on the inherent power delivery and (truer) size of music and instead relegates it to something brute, unsophisticated and undesirable? You'd certainly think that the way this vital aspect of music reproduction is sorely dismissed either (and mostly) in silence and vehement reluctance, or even downright ridicule.

Anyone can feel free to implement subs the way they see fit, that really goes without saying, but augmenting the mains run full-range with smaller subs is really only the tip of the iceberg. Perhaps it points to the need for a more radical and re-defined approach in speaker implementation that should more readily see the acceptance of DSP and active configuration, in addition to letting size of speakers and subs have its say. The latter part has been stubbornly missed out for decades, so one wonders whether it will ever find any real traction with audiophiles at large.

It seems the way it works is that if you can't go the whole nine yards with regard to physics then make it appear that not doing so is actually to the benefit of sound reproduction; indeed, it becomes a rationale in itself. 

I chased bass nirvana only to realize that what I was really missing was great midrange performance. I ended up selling my Definitive Technology ST-L speakers (towers with powered subs) and a single Martin Logan 1100x Sub.

I listen to a wide range of music: Mostly jazz, female vocalists, some live rock and blues, some country, even some electronic dance music.

I now have Harbeth 30.2 XDs with 2 REL T/9x and I'm really happy. I use the speaker level connections from my tube amp but I also use the Low level sub-cable connection from my A/V processor for TV/Movies so I get the benefit of stereo bass for my analog system and low level effects for my 5.1 surround sound system.   

A1: In my stereo pair set up the effect is subtle and depends on the recording. They add power and depth, a richness that is something you can feel. I have them located very close to the main speakers, phase is 0, crossover 38Hz (estimated, 5 clicks) and gain is 10 clicks (less then 1/3). Of course your own room and speakers will dictate these settings. I probably adjusted these 100 times before I got to the point where I didn't feel the need to fiddle with them anymore because they "disappeared". 

A2: They fill in the bottom end. The kick, dynamics etc. come from the Harbeth's amazing mid-range. They cut off at 50Hz but that does not take into consideration the room which in my case is large. 

*Most of the music is above 40Hz

*You need a stereo pair, otherwise you are summing 2 discrete channels of low frequency signal into one speaker - seems really obvious when you think about it but I was doing it wrong for a few years before a good hi-fi shop owner showed me the way forward

*I may not have bought the RELs if I was willing to buy a more powerful amp (mine is 40w pc) and large, full range speakers but in comparison, what I ended up with was a bargain and I no longer feel like I'm missing something.     

My experience has been that subs are good for Mid-Fi and Home Theatre (not so much for HQ 2-channel).

Inevidently, once I got the a sub to integrate sound pressure level wise, with my speakers (current rotation is Quad 63, ML ESL and ET LFT VIII), in my dedicated listening room, it screws up the Detail, Timing, Sound Stage or Image. Over many years I tried Electronic Cross-Overs (the closest to good), DSP and passive circuits... the experiment is now (as of last month) permanently suspended.

To each his own...YMMV.... 

I admit I did not read everyone else's answer, so apologize if I am repeating something.

First, what are your main speakers?  Some main speakers need a sub more than others.

A really good sub will be better at the lowest octave than pretty much any speaker.  This is not subtle, it is very, very obvious.

It's a matter of personal taste whether the sub is integrated well enough with your other speakers for your liking.

Benefits to the midbass are real IF main speakers are being CROSSED OVER at a higher frequency, that is to say if BASS frequencies are being diverted from the main speakers - they will be moving with smaller excursion so that should give a cleaner midrange, greater power handling.

If main speakers are still playing the whole range then benefits to mids would not be as obvious. Maybe could still occur somewhat if your need to turn the volume knob up changes with the introduction of a Sub.

"There is no replacement for displacement" (zero fidelity?)   If you need loud music in a large room, played with authority and accuracy, you need large woofers.   A more modern possibilty would be the use of small woofers combined with a ton of power and digital processing as some of the modern subwoofers just coming out recently.

There is a YouTube channel called Nemo Propaganda Reviews.  This dude knows more about subwoofers than anyone on earth!

From personal experience, deeper bass rarely loads seamlessly in the same plain as the mid/highs, and will likely interfere with them due to the greater vibration that they create

Some 10 years ago I bought SVS subs as they were inexpensive compared to audio dedicated subs. I finally sold them last year as I could not get them to blend  as their plate amp choices volume control was too sensitive, meaning even barrel cracking it, the bass would overpower the room. So, it seems high quality subs are essential, and SVS may well make them now, but not then.

hth 

The way I look at it (YMMV) is if you can swing a quality set of speakers that plays into the 20hz region you are way ahead of the game. A speaker that has good material and integrates well will run you near $20k new (YMMV). At this point you have two boxes with excellent bass down to say 24-30hz. From here you can use a sub to cover the rest. I would never want to play a sub to 35 or 50hz. 

You will get lots of opinions and mine is free and you get what you pay for. 

I suppose REL subs implement the high pass crossover or filter.

No. REL's design philosophy is not use a high pass crossover with their subwoofers.

@ryder, Subwoofers will always make an improvement more or less depending on what type of speakers you are using but there are rules that have to be followed to match the subwoofer correctly with the rest of the system. Trying to do it on the cheap can certainly be worse than doing it at all. My own experience with subwoofers goes back to 1978 when I bought my first pair. It was a love hate relationship. 

To make it brief, never start with just one subwoofer. Two is the minimum, the larger the better. You need a full two way digital crossover with delay capability. There are inexpensive ones out there now. The low pass filters that come with most subwoofers are a cheap and dirty way of messing up your system. You want to cross over as high as you can, 80 to 100 Hz anyway. I have heard systems operating at 125 Hz sound wonderful. Doing this lowers the distortion of everything else produce by your main system's woofers. Subs should always be placed right against a wall (1/4" off) or in a corner. They are more efficient this way and you cancel out a few early reflections. This is why delay capability is so important. You have to be able to match the subwoofer's phase and time with the main speakers or you just get mud in the crossover region. 

Done correctly subwoofers not only add low bass but a sense of power and effortlessness. The midrange becomes cleaner, more detailed and a system's headroom can improve up to 10 dB. That is twice as loud. There are very few systems that could not benefit from subwoofers. You can not get the feeling of a live performance without them.

I’ve found it depends on the room and the system. I’ve had set ups that no matter what I did I couldn’t get the sub dialed in and integrated correctly; the whole experience was frustrating. It either added no bass or you could totally hear the sub and it stood out. Sometimes these were in systems that needed a sub as the mains were LF restricted monitors or small towers.

On the other hand, I’ve had a couple of systems where adding a sub was magical and totally transformed the system. Like night and day different and better. My current system was taken to the next level by adding a sub and I wouldn’t go back in this particular room/system. YMMV.

I run my sub at 50Hz with a steep crossover so it does not muddy the mid bass .  Subs can not adequately fill in the gap between the common 80Hz low pass and where a speaker with weak bass rolls off.  That's the main reasonI went backto floorstanders with plenty of bass.    They don't need a sub necessarily but the sub does not call attention to itself, it only pounds out the lowest notes.

I, too, added an SVS Micro 3000. I've got a pair of KEF LS 50s. Though it took me some time to get it dialed in -- had it set too high in both volume and frequency rolloff initially -- once I got it right, it was, well, just right. I don't even think about it most days now. Which, I'm thinkin', is how it's supposed to work.

This mag editorial still remains one of the best reads on integrating subwoofer(s) into a quality build 2.1 audio system. Many of the strengths, warts, trials and tribulations also apply equally to the other major brands, and not limited to just VANDERSTEEN . This article repost has food for thought that applies to all subs faking it as marketed primarily for HT.

NOTE: the VANDY model quoted herein also has an upgraded new model in its current product offerings

++++++++++++
August 3, 2008

http://ultrafi.com/why-everybody-needs- ... 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 added an SVS Micro 3000 to my set of Harbeth 30.2XD’s a few months ago. Love it. Roll-off on the Harbeth’s is 54hz or so, so I have the sub kick in at that frequency.   It helps with soundstage and adds a little meat on the bottom.  Worthwhile certainly for bookshelf speakers.  

Subs should add that punch bass but not out front of your soundstage.   They should be  part of your soundstage.  In one system I have a 1 12 in passive sub that just kicks butt and it blends so nicely , without it the system wouldnt be anything near what it is today.  In another with larger speakers no sub but have been thinking about playing with the systems.  I have 2 10" Sunfires I can throw in and play with.  Haven't had the time but I bet I would dig it.

Net net I believe you should notice a huge difference, better performance for your speakers, deeper bass and fuller sound.  if you do not what Sub do you have and what is the rest of your system?  

A properly integrated sub, set up at 80 Hz or so, can be glorious.  As you have discovered however, it's hard to do well for everyone. It also matters what speakers you start with. 

Subs should do a few things:

1. Improve dynamic range when the main speakers are high passed
2. Give you extension to the lowest octaves
3. Reduce distortion of the main speakers, espeically when those are 2-way speakers

Properly integrated a subwoofer should not make itself known, but the stereo should sound like it's capable of enormous, effortless sound. However, having said this, it is vitally important to measure where you are stating from, becuase the -3 dB points of speakers don't mean s**t when you get them in a room.

Some excellent articles/videos here:

Absolutely night and day.  You either have a crap sub or don’t have it set up properly.  Filling out bass is only one aspect a good sub provides — it also improves imaging, expands the soundstage, and enhances an overall sense of space.  The effect is such that when the sub(s) is turned off the entire soundscape collapses significantly.  If you’re not experiencing this then you haven’t experienced what a good sub setup can do. 

The high pass filter is important to reduce the load on the mains (which are not handling the low frequencies well) and to better blend the subs with the mains.  Use a calibrated microphone and computer software, eg REW, to setup the sub positions, crossovers, levels, and phase. Be careful how the high pass filter is implemented.  If your mains are revealing you may need better than op amp circuits. A single stage passive works for me.

Adding a distributed bass array consisting of three Rel subs and one SVS sub, corrected 90% of the issues I had with the low end in my system. The low end became "real", instead of uneven and limp. Previously I tried adding one sub, but it did very little to fix what was wrong. Do some research on distributed bass arrays (swarms) and consider this as an option.

1.  Appreciable and welcome but certainly not day and night. It makes the music both bigger in size and more relaxed. It helps give support to the mids and highs, especially when it comes to orchestral recordings. The lows add presence and punch. For reasons I can't quite explain, the lows lend the sound more three-dimensionality.

2.  All my sub does is give me the deep, deep frequencies. And not even the very bottom ones, I think 25hz is about where it peters out. .

Use a sound meter or sound meter app on a cell phone to measure and find out exactly what is going on with a sub. It’s the only way to really know.  It doesn’t matter what other people think or experience.  Each case is different. 

…”At times I felt I could hear an improvement and at other times I thought the sub wasn’t doing anything”….the trick is to not notice the sub, at least until you turn it off and then realize it’s making a huge difference. If you can tell you have a sub on, then it’s not set up correctly, as you say, overly done. It can also be  a mix-match with your main speakers or too large for your room size. So getting some experienced person to help is well worth it. Getting one with DSP is also very helpful. Hope my experience helps. 

Thanks for the post. I have found my endgame speakers which happen to be standmounts. All the gear can be considered as endgame without any planned upgrades in the foreseeable future, except the subwoofer which is considered to be outclassed by the rest of the components. Hence the planned sub upgrade.

I suppose REL subs implement the high pass crossover or filter.