Go and develop a relationship with an audio component dealer. I doubt mine would ever sell me something that wouldn’t work for my room and system.
Experience with stacked subwoofers?
I have seen a handful of responses to posts mentioning stacked line array subwoofers, like the stackable Rel 510s. Does anyone have a stacked subwoofer array in their system and can speak to their experience? The marketing hype that Rel puts out about this has me intrigued. Their explanation as to why it’s awesome makes sense, but also I want to go beyond the marketing and hear about real experiences before I drop a bunch of dough on something like that.
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Whenever you “stack” speakers of any sort you alter dispersion in the direction they are stacked. Ever seen/heard of a sound “column”? This is exactly the principle, stacking shortens vertical dispersion. This is used effectively on tour sound system to shorten vertical output ( determining how far the sound is “thrown”, but maintaining a wide horizontal. Stack the speakers side by side, same thing, shortens width and maintains vertical. So in controlling bass in a space, stacking is a very common method that has been used by experts for many years. helpful in a very reverberant/reflective space. It is not something REL developed. Any competent speaker engineer would be aware of this principle. This is the argument for and against these long tall or wide arrays of similar drivers, such as using multiple tweeters next to each other in one cabinet- it creates dispersion lobes that have to be managed; its not hard to hear those lobes moving back and forth across the array. Advanced DSP can alter this inherent principle but its not easy or simple or something you can do on your own at home. I've been part of designs in studios that use linear sub arrays to narrow the width of dispersion from the subs. Brad |
At AXPONA back in April, Rel demonstrated a line array of 510s with a pair of Wilson Sabrinas (I think... I was paying attention to the Rels). Rel not only demo'd the effect of the full line array on/off, but also demonstrated the effect of running just one 510 per side, two 510s per side, and the full stack of three per side, sequentially. I was very impressed - the full line array added significantly to the size of the soundstage and improved the imaging in ways that I would never have anticipated. The effect was, of course, most significant with the full array but was present with just two of the three Rels engaged on each side. Of all the experiences I had at AXPONA this year, the Rel demo was the one that stayed with me... I've been thinking about it ever since the show. Consequently, I've begun to accumulate Rel Carbon Specials to add into my system. I have 4 of the 6 on-hand (in boxes, not yet set up), so can't provide impressions yet but am certainly looking forward to integrating the six-pack. |
Have been using stacked subs in my HT room for almost a year now. Still sorting the room out, and don't have long enough cables to put them in the proper place. To sort out L/C/R speakers, the subs had to move, so they go stacked in the corner of the room. Yes, ran DSP after. Both subs have footers under them, to isolate from each other. They sound just fine, get all the bass I could ever want and then some. Once stacked, both needed the gain to be turned down. Think it's a little cleaner, but these are movie subs, not musical. |
@bobelton What is your low frequency goal? 1. The addition of the subtle extra low frequency from instruments and effects found on so many modern recordings? 2. Reinforcement of your current speakers woofers? Speaker positions are often in an area of the rooms null. A null can deplete the bass output of most any speaker even those equipped with powered subwoofers.
Since -6dB Sub-Bass Systems (woofers) roll off so dramatically they simply do not excite a rooms standing wave bass modes which allows them to be positioned most anywhere in a given room. The trade off is the rated extra low frequency rolled off output is barely audible regardless of how many woofers are used. Despite this limitation and for what ever there experience, there are many satisfied users. If your goal is number 1 you’ll need to be shopping for actual -3dB subwoofers. Here a subwoofer array (distributed bass array) is typically corner placement of four cabinets were their output loads the room equally mostly eliminating the room standing waves. The extra low frequency presentation is quite stunning in my in home experience. Using one to three -3dB subwoofers requires more precise positioning. All the best in your search. |
If you have decent speakers you only need one subwoofer maybe two. It’s a gimmick from a marketing standpoint. Not sure how meaningful the changes and I’m not hearing much on what it does up above and there seems to be limited enthusiasm. Why not Stack tweeters and mid range drivers. I stack my dishes and silverware and that really works good. |
Thanks for all these responses. I have two Rel t7s in stereo in my current set up, which were one of the greatest improvements made. In my own personal experience, I have found subwoofer replacement and even toe-in to make a significant impact on the quality of the base that I hear from the listening position. Not just the amount of bass, but the ability to hear distinct differences in the notes from one to the next. Having experienced a dramatic difference with that, I’m imagining that adding a height dimension would also be significant. So I’m intrigued with the idea of stacking three subwoofers, each tuned to accomplish something slightly different. |
Well, tomorrow is my day to try dialing in my REL S/510 four-pack. I’ve watched John Hunter’s Youtube about doing that setup for a six-pack. When my dealer delivers my last pair they will send their expert on setup to help get me sorted, so I’ll see how close I get to what they think is good, at least up to the point of working on fine tuning. I even have the Sneakers Track 4 audio they recommend , ready to go on Qobuz. |
@simonmoon: The GR Research/Rythmik Audio Open Baffle/Dipole Servo-Feedback Woofer is definitely the best sub I’ve ever heard. The one in your picture is not actually a stack, it is the 2-woofer version of the sub, also available in a 3-woofer version (the dipole cancellation inherent in open baffle subs makes a single 12" woofer per side insufficient in maximum SPL potential). Most audiophiles will never hear it, as it is sold as a DIY kit. However, GR Research has a couple of cabinet makers who will build a pair for you (for a price, of course). Advice for potential buyers of the sub: The Rythmik Audio A370 plate amp that comes with the kit is solid state, so is of course optimized for a 4 ohm load. The woofer used in the sub was optimized for open baffle use by Danny Richie, and is available in both 8 ohm and 16 ohm versions. Danny routinely sends the 16 ohm version with the kit, so that 3 woofers may be used with the A370 plate amp (the combined impedance of 3-16 ohm woofers is around 4 ohms). However, if you intend to go with the 2 woofer version, get the 8 ohm woofers rather than the 16 ohm. The 4 ohm combined impedance of 2-8 ohm woofers maximizes the power output of the A370 plate amp.
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Having experimented with different subs and arrangements in-room I can say with some authority that the results you get may surprise you. And it can go either way. My experience supports the fact that if a single sub is good, then two is way better, and not stacked on top of each other in one corner. While that gives you more output, it won't help control room modes and give you even bass response thru the room. Separate the two subs and treat them like they are stereo because bass is not monophonic. It does not mean they have to mirror image in terms of positioning but try running them on either side of the screen or tv out from corner along the front wall assymetrically and run some measurements. Keep playing with positioning until you are happy with the results and then do some DSP on the remaining peaks and you should be in pretty good shape. That second sub will even out the response and give you 3 db more sub output, helping perhaps cut down on low freq distortion a bit. Well worthwhile expense to add the second sub. |
Stacking subs is not a gimmick or a marketing ploy. But its effectiveness does relate to your goal sad others have said. One sub is nearly Omni in a room and expose standing waves everywhere. Moving it often just moves the stadium g wave/ null location. If it’s for home cinema, most of the sub output is sound effects so almost everything relates to the screen. If it’s for music, distributed arrays can work better using multiple sources turned down at lower levels especially in ATMOS/ immersive. I think Duke has spoken about this extensively. |
Standing wave problem is overrated and most rooms don’t have this problem. Lower bass waves are very long and permeate throughout the room quite well. Also if you have decent main speakers for two stereo listening you shouldn't really need to have a subwoofer. Fully endorse subwoofer or two for home theater, you want tanks to rumble your entire house when they move across the screen |
I'm with Brsd on this topic as it's settled science going back to work done back in the early half of the last century at Bell Labs. Very common in PA application, not as common in 2 channel home applications.
BTW Brad, I picked up some used SAM'S powered by a Benchmark stack. Very pleased with the results. I'll stop by the next time I'm in town.
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An awful lot of old people still voice “you shouldn’t need subs” and I think this was accurate in the days of Led Zeppelin, early Genesis, English rock and roll. What I see these bands doing with subs on the recording side has certainly ended that idea. Pop music (Ariana and Sabrina carpenter ) - Americana ( Sarah Jaroscz) even country (post Malone/Jelly Roll/ chris Stapleton, Kane Brown ) -are working the subs hard. Brad |
I suppose nobody "needs" subs, but damn, they can make an huge improvement when you abandon need and go all out for want, and take the time and effort to dial them in properly. I spend the afternoon setting up the first four REL S/510 of my six-pack line array....and damn does that sound good...and I still have some fine tweaking to work on.:) And I am an "old people." |
After the ten minutes spent locating my rooms two strongest standing waves I position the two twelve year old subwoofers within. The twenty minute Auto EQ runs while a Sweep Tone CD is played through the main speakers as each subs fourteen parameters are adjusted to both the speakers and the room simultaneously. Followed by a minor five minute manual tweak to personal taste all from the listening position, close the laptop and done. I'm not only old, I'm a lazy idiot. I still have that silly Columbia 'Sneakers' LP - that 'Cosmo' (Kramer) track, jeez. Best of luck with that. |
I added a six pack of REL Carbon Specials to my Rockport Cygnus (which have great bass already for size and price) about 6 months ago. The added bass support was fun with modern soundtracks, but the creation of the "space" of the venue was something I have never been able to access before. My wife thought here he goes again on a wild goose chase, but was immediately saying that she loves them. It is the most significant upgrade beyond different main speakers that I have achieved. Once you hear what they can do, I don't think anyone will want to go without them. It's so not about more bass, the first two subs did that. It's about how much more engaging the experience becomes. If you notice several top of the line exotic brands have 4 box speakers with two of the boxes containing...you guessed it, three woofers. This set up is similar to my six pack next to my Rockports. Everyone who can try a 6 pack of subs should try it. I can't imagine going back to just mains. |
I have been dialing in my second pair of REL S/510 as a four-pack array, while I wait for delivery of the third pair. Even going from a stereo pair to a four-pack has been an amazing revelation. My wife was skeptical, but she is enjoying the change immensely and starting to ask me to play stuff she loves to see how much better it sounds. She's now asking when the last pair will arrive and get integrated. I should get my third pair of S/510 soon to complete the six-pack. This is becoming a revolutionary change to my system. MIND. BLOWN. |
@wokeuptobose & @dwette YES, Yes, yes. This is what I heard at the AXPONA demo. While the six-pack clearly delivers more bass (yeah, they're subwoofers, so that's obvious) the impact of the RELs was shockingly apparent with regard to: (1) size of the soundstage (2) precision of imaging. I went into the demo thinking this was just RELs attempt to sell more subs (a "marketing gimmick" as @emergingsoul put it) or more charitably an attempt to even out bass performance (as multiple members have implied with their comments). I left the room shocked and awed. My first thought was... how can I ever again assess the sound quality of ANY pair of speakers without an accompanying REL six-pack? I'm sure many will write me off as a kook. That's fine with me. I heard what I heard. |
Which manufacturers other than Rel make subwoofers specifically designed to be stacked? I’m assuming here that there are different design decisions that a manufacturer would need to make for their subs to be optimized for stacking. In particular, are there any stackable subs below the Rel 510 price point? |
These guys are marketing a change in the sound dynamics in a room. Exploiting human nature. Just because you hear a change doesn't mean things are getting better. So now what are we gonna start doing stacked mid range and tweeters?? All this Because main speakers are now this made with smaller diameter bass drivers. |
Love this discussion as this is something I'm planning myself at the moment.
Has anyone considered running their line array via DIRAC? I personally really like the feature and want to continue using it but unsure how to make it work without sacrificing benefits of the line array. In particular the fact that I don't think you can set independent crossovers per sub via DIRAC (and the line array method seems to be to run the xover higher for the higher subs in the stack). Was thinking about hacking it with a combination of the dirac xover and onboard sub xover function. |
@guysellingstuff Why not contact REL and ask what they think (I’m guessing no to DIRAC). They have very responsive customer service. But to answer your question, no, something like DIRAC has no place in my two-channel system. I'm not even sure how that could even work for a REL line array. While I do have a digital streaming source, my primary playback source is all analog (turntable with two tonearms). |
Oops. In my comment about the post above by @simonmoon regarding the GR Research/Rythmik Audio OB/Dipole Sub, I neglected to say that AudiogoN member jaytor includes pics of his stacks of the 2-woofer model of the sub in his virtual system. Four 12" servo-feedback ob/dipole woofers per side = awesome!
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You sound like you have no practical experience with the use of multiple subs and are merely parroting outdated information. Adding a distributed bass array consisting of four subs (not stacked, but distributed throughout my listening space) to my two channel setup resulted in the single biggest improvement to it's overall sound quality. |
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Hi there, this discussion caught my attention in my weekly update. I have dabbled in this space and have a few points to consider. Its necessary to consider the desired outcome, if it includes accuracy attention can be given to many things, for example minimising 'noise' in digital chain typically improves bass, and will reduce pressure loading in the room. Power conditioning and cables are very important which is expensive when setting up distributed subs. Subs fuses matter too. 1 well implemented sub might be better than 6 done poorly. Line arrays and distrubted bass drivers are common in large venues and there's plenty of science in that field to consider. They rely on managing/coordinating specific placements, delay, and active crossovers. Complex compared to most home 2 channel systems, and also they're not focussed on a single listening position. Integration with main speakers is critical. I use active crossover including to roll off mains. Placement of subs in the room is important, next to the mains might not be ideal, I've found against the wall behind the main speakers better, and a specific distance from the corner. RELs approach seems adopt the simplest set up I assume to not put people off (from buying more subs). You can do arrays with any subs. However, it's probably easier to use identical subs than different subs which might have different phase and group delay (I have subs with 4ms delay from input to output, and others 12ms, this makes it awkward to coordinate phase and delay with the 12ms on top of the 4ms - same pair each channel). The benefit of having a stack of three subs might not be that there are three, it might be the placement (height) of them in relation to ceiling height and pressure zones that matters. I use a rack (from hardware store) to place my subs specific distances from the floor). I hope this is helpful. |
@dbastin Haha. Yes I guess you could count them that way. I certainly don’t lack any base in music or movies and the room is loaded effortlessly. I integrate them using an active crossover using 12 biquads per channel made from using Room EQ Wizard and Multi Sub Optimizer. They are all time aligned, adjusted to eliminate room modes, etc. I’ve got better base than the megabuck systems I heard at AXPONA. It is musical, accurate, no bloat or notes that sound out of key, it’s natural but will shake the room on big music transients or explosions in movies. I wish the younger generation was into this. It’s such a cool hobby, people are blown away hearing it but aren’t interested in anything technical or how it works. We all prioritize how we want to spend our time and money. |
@hifidream Do you know of a published manufacturer frequency response ( ex. -xdB@xxHz ) measurement for Kinergetics SW-800's? I get led to an SW-800 User Manual residing at Hifiengine but I'm unable to log in. |
Yes, I have the first four pretty nicely dialed in. Foundational bass sounds great, and the mid bass attack and response are much improved. The soundstage has improved considerably, and is more three-dimensional. I can especially hear that when playing large scale orchestra music. I'm still waiting on the third pair from my dealer. They are their last demo pair, but an amp was damaged and they have ordered a replacement from REL. As soon as I get them I will add them to the stack and work on dialing them in and fine tuning the final array. I had been thinking about doing this for a long time but didn't want to spend the money at retail cost, so I'm glad I was able to get two pair of the dealer's demo array. |
My room is a bit of a challenge with it's smallish (11' x 17') size. I have the speakers a bit closer to the side walls than they should be, but that's to get them 8' apart for a bigger, broader soundstage. The subs are just to the inside of the speakers. REL recommends them to the outside, but say inside also works if there are space constraints. Despite the challenges it all sounds great....better than I would have thought otherwise. My wife and I plan to move the whole thing to our living room, which is 13.5' x 22', and 1/2' taller (8.5' vs 8'). That should give it all more room to breath and allow positioning the subs to the outside of the speakers. We have some logistic things to work out first though (e.g. turntable isolation).
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