Single vs. Dual Subs
Perfectly flat, no. With a bit of room correction on the mains, the REL B1 ran 100Hz down to 31Hz, +/-2dB in the listening seat, and the sub's location was invisible (low pass 23 and low vol). Still, the B1 went into the home theater and now have three sealed SVS subs (3000 and 2000s) in a DBA type array, which is better than the single sub. |
"Seems" and "is" are two very different things, for sure when it comes to subs. Duke makes his Swarm with plugs enabling you to convert one or more ported subs to sealed. After studying the matter and talking with Duke mine were made with two ported, two sealed. I also have a 5th sub that is ported iso-baric. The truth of the matter is there is no "integration" process with a DBA. You plop them down, you set the levels, they are "integrated" whatever that even means. To me it means the bass is seamless with the rest of the sound stage. This happens automatically. You could use five completely different subs or five all the same, no difference. So save your money. |
Okay, so if going with dual subs, can you mix and match sub brands? Seems like sticking with the same driver size may make a difference. I have a Paradigm x10 but was thinking of pairing that with Sonus Faber sub to pair with my SF speakers, but I might be better to go with a second x10. Integration with the same brand seems obviously a lot easier. |
I am currently running two subwoofers. It’s not talked about much but the biggest improvements come in mid range clarity And the highs have a little more pop also not to mention increased soundstage and detail. I also found out that the best sound that I got was from stacking my subwoofers so don’t be afraid to experiment !!! |
Properly integrating a sub is really hard work, and rarely done by 90% of those who buy a subwoofer. Technically, correct! I would even go as high as 100%. But 90 will do. Which is why I always and only recommend a DBA with 4 subs. Try and do it with just one and you are doomed to failure. When even the guy who uses one knows it is really hard work, and even then works only rarely, everyone should listen. And then go out and get more subs. To do it right. |
Properly integrating a sub is really hard work, and rarely done by 90% of those who buy a subwoofer. As a result most audiophiles have never heard a single subwoofer properly set up and think that stereo subs matter for the sake of Left/Right imaging or sensation. They do not if you set them up correctly. They matter for frequency smoothing, and then only in cases when you have absolute control of their placement, and then, only somewhat. Better room acoustics and EQ can make a single sub sound glorious and enhance the experience from dual subs as well. Most audiophiles also try to stick to subs below 40Hz, when in fact cutting off their mains at 80Hz or so tends to greatly reduce doppler distortion (assuming small 2-ways) and increase the amp dynamic range. Sadly people tend to want to just throw money at a problem that needs expertise. Hire an expert, or get a system with built in room calibration and sub management. You’ll be really glad you did. |
mc, Why state the obvious, then attempt to justify it? Why have two Low Bass Stereo SUB Woofers, when as you state it's difficult to record Very Low Bass Frequencies in Stereo? Wouldn't summing Left & Right Low Bass Frequencies Electronically, (which can be done efficiently, with a Summing Electronic Cross Over) then playing them back from a Central Low Bass Sub Woofer, as I suggested, provide a better option? As I indicated, I still have Stereo Bass from my 12 Inch Sub Woofers for Localization of those Mid Bass Frequencies; via their placement on far left & far right, which provides such localization for those frequencies. Providing Very High Power to a Single Centralized Low Bass Sub Woofer definitely puts the SLAM into those frequencies, which can be felt, but not heard by most people. Try it, I guarantee that you will like it! eagleeye7 |
What if the HOW is automatic? What if it turns out the HOW cannot be anything BUT? The wavelength at 80Hz is 4.3m or about 15 feet. At 20Hz it is over 17m or about 55ft. https://www.translatorscafe.com/unit-converter/en-US/calculator/sound-frequency-wavelength/ HOW are you going to ever manage to record that in "stereo" with any sort of ability to localize the sound without using microphones placed at least that far apart?? And in a room many multiples of those dimensions? HOW are you going to do that? Even if you do, HOW are you going to manage to play it back in stereo, in a room with dimensions smaller than the wavelengths involved? HOW? |
All IMO:
My perspective is from fidelity and integration standpoints. If you want to be punched in the stomach [which does not happen when recording a kick drum] I'm outta my depth. see ieLogical SubterraneanHomesickBlues for more info and a primer on integrating small subs. |
“Two or more subwoofers also help in reducing low-frequency distortion and offer improved dynamics over a single subwoofer. This is a simple function of having more radiating area, plus more power on tap.” I suspect that we all understand that bigger drivers and more powerful amps are usually good for bass. ‘Twas ever thus. But many of us have $, space and spouse constraints. I’m considering getting sub(s). My question is more like, “for the same money, are 2 10” subs likely better than 1 better (and more powerful) sub?” E.g., 2 REL t/9i vs 1 REL S/510 cost about the same. For that matter, is there a consensus (here? Lol) that REL is likely better for 2-ch than JL Audio or SVS? |
divertiti, I have a similar situation to you, relative to Sub Woofer Placement. I solved it, which IMHO, has optimized the results, as follows. Here's my solution: 1) Set of 12 inch, self powered 500 Watt Subs at Far Left & Right of room, set @ 70 HZ Crossover. 2) Single 15 Inch Sub Directly in Center. This Sub Woofer is Fed its signal from a dbx 234S Electronic Crossover set @ 40 HZ Crossover Frequency, & set to SUM Left & Right Channel Inputs, which signal is in turn fed to a Classe 25 in Mono Mode, putting out an honest 1,000 Watts. dbx 234S gets its signal directly from the second output of my pre-amp. 3) Combined with PS Audio BHK Signature 300 Mono Blocks, feeding a pair of Anthony Gallo Acoustic 3.0's, three way speakers. This combination of Speakers puts out Exceptional Non Boomey Bass with Massive Slam, as the 15 Inch Sub Woofer is driving directly into one, when they are sitting in the sweet spot. I find the "Single Very Low Bass Sub", summing both Left & Right Bass signals to be optimum for Deep Bass, while not interfering with the music that one plays. |
Hi divertiti, As someone who has had a variety of two channel monitors over a long period, differing rooms and challenges, I've discovered that a pair of subs properly matched to the personality of your mains is terrific. My sealed subs are positioned below my monitors, with a radiating pattern that integrates nicely with the mains in a fairly nearfield, small room, well away from front and side walls. My pro dac steeply rolls off 80hz down to their tube amp for the mains and the subs from 80 down to the high 20's with purity and resolve. This arrangement makes for a very coherent and near full range presentation. The disappearing tricks of great monitors, staging, et al work their magic, with appropriate slam. I considered a swarm but decided against it in a small studio. Bonne chance, divertiti! More Peace, Pin |
mijostyn, I appreciate your suggestions and yes I'm pathetically stuck on analog but our low frequency system is master and slave digitally processor controlled. At shows I'm regularly impressed by total bandwidth room correction demonstrations and then I walk into an analog demo and am often quickly reminded. divertiti, after many 18" single subwoofers when some dedicated subwoofer manufactures began designing ten and twelve inch top line models I liked the idea of at least two smaller units. After experimenting with four subs I found my room loaded nicely with just two 12"s running summed L/R located asymmetrically in the rooms largest bass modes. Good luck with it. |
Caveat: not interested in the SWARM method or multiple subs at the moment, strictly comparing single to dual subs Second who said the first sub can’t have 6 active drivers and 12 passive radiators, BUT all in the same SINGLE 50 cubic foot box. :-)I’ve got dual opposing drivers in the same enclosure (internal vibration cancellation), both dual voice coil 10". It’s been on springs since the day it was dragged into my system, abused for being so heavy and awkward. I cannot get another class D amp module to match the one I have, so I’m thinking of making two more dual opposing driver subs (they will be on springs also) and using four drivers in two enclosures. Taking my 2 x 400 watt AB power amp to drive just the subs, and go valve for the stand mounts. May toy with using the dual driver sub I currently have somewhere in the mix as well?? As I’m strictly digital at the moment, a DSP isn’t a bad idea, I’ve only used one in the car, with excellent results. The DSP was used on a single sub. So I have experience with single subs, however, I do believe it's an upgrade to use more. |
The Vienna Acoustics Mozart Grand SE claim 30Hz bottom end. It's a ported design. The subs are unported and thus the bottom end characteristics are radically different. It's a good move to use the miniDSP. Turn the sub's XO frequency all the way up and set Phase to 0. You should use something other an integrated so you are not driving the main speakers full range. With a 70Hz corner in the miniDSP, I surmise there is a LOT of incoherent bottom and mid-bass in the room. 70Hz is easily localizable. Having used full range monitors in recording studios and subs at home, it my experience that maximum musical impact occurs with coherent low end. Good luck. |
I'm running a pair of Tekton 4-10 bass towers & am very pleased. Prior to this, I was using a single REL sub. The bass towers improved not only bass (as expected) but also soundstage width, depth, instrument separation, & top end clarity. A very nice improvement top to bottom. I have these in a dedicated room that is around 15' square. |
@m-db, The much better solution is using digital bass management which includes room control and digital crossovers which are far better than analog crossovers. From less to more expensive you have MiniDSP, DEQX, Anthem and Trinnov. Check them out. If you are a person who is stuck on analog only just forget about it, my mistake. |
Miller +1on subwoofer isolation. My subs have been supported on foam padded dollies with extra soft rubber wheels for many years now. After a move and before a permanent system setup we had our single 18" sub sitting on some folded moving blankets. We noticed how much less the low frequency excited the structure while still providing deep bass. When we purchased our current 12" subs ten years ago I connected the 12s and the 18" with RS-232 cable and the home theaters 15" Super Nova with L/R interconnects. Effectively creating what's now called a swarm which did indeed eliminate all the rooms bass modes. We noticed little if any sonic advantage between Cardas Golden Reference XLR to Canare XLR. On the other hand when I applied the four subwoofers with fourteen parameters of the subwoofers Room Optimization the improvement was stunning while adding the flexibility of remote controlled preset equalization. I'm very interested in the "much better solutions available" you mentioned? |
Indeed, the multiple sub solution outlined by Toole and on which the Distributed Bass Array approach is based is a game-changer. Multiple subs distributed asymmetrically around the room effectively minimizes the problem of bass modes. Then when the subs and everything else are isolated on Townshend Podiums and Pods this virtually eliminates another major source of room mode excitation. The combination of the two is stunning. It takes a huge amount of bass traps and other room treatments to match what isolation and DBA can achieve. Then if on top of all that you go to Townshend F1 cables, these eliminate yet another source of harmonic resonance. The old-school approach of EQ and room treatment really is old school. There are much better solutions available. People are catching on. Good to see. |
As of this moment. Musical Fidelity M6si integrated amp. Vienna Acoustics Mozart Grand SE Audioquest Black Lab sub cables Room 9"6" high x 12' wide x 16' long Speakers 4' from front (12') wall Rel T5 (2) located behind main speakers 24" from front corners SVS SB-2000 rear left corner Sunfire True Architectural Signature Sub behind couch. Midway along right wall. The MinDSP has just a basic setup of all crossover points at 70hz. I have downloaded Room EQ Wizard, purchased a MiniDSP Umik-1 microphone and will be doing an analysis when I am feeling motivated. This allows me to create a parametric EQ file to import and do a final tweak. REW will also provide me with a roadmap for adding room treatment as required. |
Save yourself a lot of time and effort and go directly to a Swarm. I just set mine up two days ago and it was an epiphany. All my bass issues were resolved immediately. Smooth, balanced, realistic low end. Now it's time to tweak things. Very simple. I used a MiniDSP 2x4 connected to the pre outs on my integrated, set the parameters in the software, then connected the outputs to 4 subs (two REL, one SVS and an older Sunfire). Only downside is more wires running everywhere and five more power cables. |
Using a Dual Rel T7i subs make my soundstage become wider and deeper, comparing to one subs only. Also, the bass goes deeper and smoother. I am not a scientist, so I don't know how to explain it, I can only report what I observe. Also, placing the dual subs right next to the speakers closer to the side wall makes the soundstage wider, comparing to closer toward the center . |
Recently blew a sub in the living room where I run a two sub system for video. Decided to move the matching sub from my listening room there and replace the listening room sub with something newer. New Martin Logan 800 X (10" sub) to augment the 8" woofers in my classic Acoustats is working beautifully. Everything adjusts from a phone app at your listening position and it has Anthem Room Correction built in as well. Sub is tucked away behind the couch wood arm at the far right. It's gets lots of reinforcement coming out of that couch "baffled" corner. https://www.martindareff.com/Other/HDR-Treated-Images/i-3ZfL6Gq/A |
Don't forget that ours ears are not the only way we experience the music we're listening to. There are pressure sensing structures called Pacinian corpuscules distributed over the entire surface of our skin that contribute to our perception of lower frequencies. I'm not sure whether these sensors are wired to our brains in a manner that allows source localization, but it would make sense if they were. It's a fact that having appropriately distributed multiple subs (more than 2) improves the bass. I wonder if anyone has looked into whether it makes a perceptual difference if you try to keep the channels separated from left to right when you place them. |
Just for the record, I do this regularly with a single sub, traps and careful use of an EQ.I guess the advantage to doing it this way is that there is less trial and error involved. If we ignore the EQ for a minute then room treatment only attenuates reflections but it happens over a wide range of frequencies. The only limit is how much space you're willing to give up to absorbers e.g. to treat a problem at 80Hz you're looking for 1m depth of treatment... 1.5m at 60Hz etc. With EQ I think the only compromise is that you are getting a flatter response at the listening position but probably making other places in the room worse. Theoretically with multiple subs you should be able to cover multiple frequencies but it could easily turn into a game of 'whack a mole' where you treat one node only to reinforce another one. I guess some of you EQ each sub individually to get around this. Personally low frequency room response is somewhere I'm willing to compromise... treat the worst modes and live with the rest. Each room has imperfections which are part of its character if you're willing to think of it that way. |
My system is a great example. There are 5 subs asymmetrically placed around the room with each one a slightly different distance from a corner than the others. With music playing, even with plenty of bass, you can walk right up to any of them and think it is disconnected. In fact I wasted a lot of time in the beginning doing exactly that! Just for the record, I do this regularly with a single sub, traps and careful use of an EQ. |
Everyone needs to go to another live concert and ask this question (assuming the sound system is a good one) Why does this sound better to me. Why does this feel better to me. Jazz in a smaller venue is perfect. The idea is to recreate that sound and that feel in your room. Having a room longer than 30 feet is a big help but not mandatory. A lot of systems have the capability of doing this. What is usually missing is the bass. It requires a lot more than people realize, a lot more speaker and a lot more power. I just get there using 7000 watts and four 12" subwoofers. It requires a 2 way crossover with steep slopes and the ability to delay speakers to get them aligned correctly. Just adding bass is not the point, it is getting to realistic bass. No speaker that I have ever heard had realistic bass down to 20 Hz, not a Wilson, Magico, Magniplanar, or Apogee. It takes a specialized driver in a very heavy stiff enclosure and a lot of power. You could use one really big one but IMHO it is easier to live with multiple smaller ones than one huge one. In my case it is absolutely necessary. IMHO if you are going to add subwoofers wait until you can do it right. It can be very frustrating if you don't and waste a lot of your time. @erik_squires , forget about simulations. Measure actual setups and see what they do in reality. A simulation can not possible cover all the variables involve like what frequency the walls resonate at. Are the subs well matched or are they 90 degrees out of phase with the main speakers. Why do some people think their subwoofers sound better 180 degrees out of phase? One sub may do fine in an 8 X 10 foot room or as fine as you can get in a room that small which is not very. Do not make up your mind on someone's idea of what a simulation should be like. |
xcool - Our ears aren't good at locating low frequencies so subwoofers don't contribute to the stereo image. In fact you will probably find that the best locations are not near your speakers or symmetrical. Excellent answer. My system is a great example. There are 5 subs asymmetrically placed around the room with each one a slightly different distance from a corner than the others. With music playing, even with plenty of bass, you can walk right up to any of them and think it is disconnected. In fact I wasted a lot of time in the beginning doing exactly that! HOWEVER in spite of this when listening to music it is incredible how the bass always has some sort of definite location or character. What makes it so incredible is this happens even with bass notes that seem to have no sharp transient or leading edge. Like a big drum whack, it makes sense your ears are cued to a location by the initial whack on the skin of the drum. Or pluck string bass, same thing, the initial string plucking off the fingertip. But all kinds of bass does this too. It SEEMS to be localized BUT it is NOT and the proof is I can run the amps mono and STILL hear the exact same localized bass! None of this makes any sense other than our hearing does not localize very low frequency bass but does localize higher bass AND THEN combines the one with the other to form a clear image of where the whole thing is coming from. In other words, a great example of psycho-acoustics. |
I use a pair of Velodyne HGS-15s in the corners of a 14’ X 19’ room with acoustic room correction by an SMS-1 to supplement KEF Reference 1s below 80 Hz @ 24 dB/octave. The result is excellent. I’ve tried a couple of high-pass filters, but they seem to take a bit of air out of the sound, perhaps a peculiarity of the sticking them between an Ayre preamp and amp with the zero feedback. |
xcool - Our ears aren't good at locating low frequencies so subwoofers don't contribute to the stereo image. In fact you will probably find that the best locations are not near your speakers or symmetrical. What you're looking for is for each sub to excite different room modes so that they balance one another out to some degree. If you're not familiar it might be worth looking up 'room modes' and 'standing waves'. There are also some neat tricks for finding good locations although the whole process is a lot easier with a measurement mic and some software. You need to also make sure that the speakers are 'time aligned' which you can do by measuring and with some simple maths. |
Hi, I have a similar question relating to 2 vs 1 subs. I currently have a single REL sub sitting right next to my right speaker. If I were to add a second sub. Does it need to be placed symmetrically to the first sub? i.e. right next to my left speaker. The reason I ask is I simply don't have the room to accommodate a 2nd sub on the same side of the wall where my speakers are. So is it ok to place the 2nd sub somewhere else, like on the opposite wall diagonally from the first sub. Will that ruin my stereo imaging? Thanks very much. |
carlsbad, I have been using ESLs for over 40 years and am very familiar with the CLS. When you get the second subwoofer get a two way crossover. Rolling the bass off in the CLS's will result in a very large improvement in distortion and headroom. You will easily get another 10 dB out of the system. Cross up between 100 and 120 Hz. I would use a Mini DSP to do this. That way you can use steep slopes and you can time align the subs to the CLS's which is very important. You will soon realize that the crossover is the single most important piece of equipment you have. Also, do not put the subs behind the CLS's put them outside the CLS's preferably in corners right up against the walls. They are an easy 6-9 dB more efficient in this location, the sub does not have to work as hard and this lowers distortion. |
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I would say that with dual subs you can have stereo bass if you mount them in the same plane as the main speakers if you use a single sub you need one with a blend circuit and again mount it in the same plane as the speakers both types work well for music but finding a good single sub with a proper musical sound is more difficult. Same plane is no more than two feet forward or back from the main speaker baffles. |
