3 subs better than 2?

Without benefit of a room analyzer, one will "NEVER" know the true extent of the benefit of adding an additional sub to a two sub subwoofer system. The same for parametric settings. I've found through personal experience that with multiple based subwoofer systems there's a push-pull relationship going on between the output of multiple emitters. As the output of one is increased, the measured output of the other will be decreased due to the complex interaction of sound waves in a room's acoustics; cancellation.

Placement and parametric settings are paramount and without room treatments to attenuate sound wave reflections, one is pretty much guessing as to what the best their system is capable of. Without benefit of a room analyzer, one will not be able to see this push-pull relationship taking place and if one is depending on their brain and hearing to dial a system in, will "NEVER" achieve the best out of "ANY" system, irrespective of it being a two, three or four subwoofer system.

The point of my above, before adding a third or fourth sub to your system, my recommendation is to expense time and money to acquire room analyzing capability and spend the time to empirically get to know the subwoofer system you currently have control over. And then when satisfied you're getting the best out of the system you do have control over, add additional subs as then you'll know why you need the additional subs and have an idea of what to expect the additional sub to add to the subwoofer party.

I don't find it surprising at all that multiple dissimilar subs sound good. I don't see how having non matching subs is any different than having surrounds that aren't the same as the fronts or centers.

Generally speaking, 3 subs will sound better than 2. It's more likely the third sub will even out the room response than it will cancel out the other subs.

Understanding the penalty of living with a fully plated life, anything that will aid you in seeing your room's acoustics is a good thing but in my opinion, one needs a full spectrum analyzer as opposed to a 1/3 or 1/12 octave analyzer.

Yeah, I thought REW was confusing and complicated at first, too. It really is very easy once you get the hang of it though.

More reference points. That's useful if you have a parametric EQ that allows you to set the EQ center frequencies. It's not really useful if you have a 31 band 1/3 octave EQ.

A real picture of the room's acoustics as opposed to the, in my opinion, useless information a 1/3 octave report gives.

Real time analyzing depends on full spectrum information and if one is depending on chopped up information then that's what they're depending on, anemic, chopped up information gaps which create visual distortions based on intentionally cutting out valuable and much needed necessary information. Think quality of sound based on lossy, low resolution playback while standing on a rush hour subway platform and if someone feels that's their cup of tea, have at it.

Using this type of information will assure one of not accurately seeing the information stream which makes up their room's acoustics and if doing this will guarantee their inability to see the nuances of the changes taking place and is guaranteed to hamper their efforts to successfully integrate their subwoofer system into their room's acoustics. If using 1/3 or even 1/12 octave, one is not going see minute changes taking place as the insensitivity of the analyzing program will hide and prevent changes from being seen and will give one a false sense of security base on the distorted reality lower end analyzing programs provide.

Any information presented in a smoothed format (less than full spectrum) is nothing more then an effort to clean up the soul bearing slop the graph is based on. We use graphs to show us the reality. We don't use graphs to hide reality. 1/3 octave hides reality as does anything that's less than full spectrum.

If using chopped up, inaccurate information makes one feel all warm and fuzzy inside, then they should go for it because accuracy is not what their quest is about as they're good with the slam-bang approach and then reaching out asking why their system lacks quality bass reproduction.

My personal experience has shown that one can't use information which has any smoothing applied as doing so hides ringing (reverberation) in a room's acoustics and fails to communicate the bloated nature of the room's acoustics. Much of which, via judicious use of parametric settings, "CAN" be corrected for without need for "UGLY", wife angering, uber expensive, room treatments. In my opinion, based on personal experience, using 1/3 octave is a total waste of time because it won't expose ringing, cut off highs and low SPL readings (think square wave), will gap (gloss over) nulls (valleys), modes (peaks) and hide shoulders.

In short, you ain't gonna see what-cha wanna see if trying to see with the foggy glasses that is a 1/3 octave analyzer. Hopefully my above will help elucidate why full spectrum is paramount as opposed to trying to go it on no cost, 1/3 octave, freeware.

...............

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Edited by BeeMan458 - 3/15/13 at 8:40am

OP, please note that the two uses of the term "parametric" in the above quotes have very different meanings. Bill's use of it is correct; BeeMan's use of it is just confusing. I explained it here:

Craig

In my opinion, your above is as good as it gets but you will need a recording mic (if you have a laptop, consider a USB recording microphone) and don't listen to anybody who says get a Radio Shack digital sound meter. Get a "decent" sound meter as there are differences in quality and the recording modules are not all the same as there are four sound meter standards, not one, with the Radio Shack model (which I have owned and used for years) representing the bottom of the standards list. FWIW, I have several sound level meters, each being a higher standard then the last.

Please, understand the need to take the needed time to learn about the use of the measuring gear, REW so as to get the miniDSP up and running along with the available integration with REW so as to gain full benefit. Understand there's the need to include necessary time to integrate the subwoofer system into the room's acoustics.

Just saying,for one with a fully plated schedule, this can create it's own set of scheduling problems. Based on what was said about having a full plate, this is something to consider before lighting the candle. I'm not trying to discourage, I'm only commenting, based on your comment, so as to make sure you're understanding this will require time and effort above simply plugging things in and hitting the enter button. Overall, after suffering the indignities and frustrations of the learning curve, once up and running, for what you discover about your system and your room's acoustics, with the setup you've considered, you'll be dancing in the streets with joy-joy, happy-happy.

One point should be included, see your above choice as an intellectual journey, not an intellectual end. See this as a long term journey to sonic places you've never been before. See this as an awakening that will give you joy, happiness and the type of pleasure only personal satisfaction can give.

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Edited by BeeMan458 - 3/15/13 at 9:59am

...


Sorry, that was a mis-step on my part as one needs a program module to go with the miniDSP and I took the UMIK-1 to be the module as opposed to the recording microphone.

The USB microphone I'm familiar with is one from Parts-Express, the Dayton Audio UMM-6 USB Measurement Microphone The one from miniDSP Inc. and Parts-Express seem to be the same unit but they have slightly different specifications, including their overall weight is different. Could be the weight of the black paint sprayed onto the Dayton unit but at a weight difference of 148g vs 120g for the UMIK-1, a full ounce, I doubt it's the paint. .

Have you considered a plug-in module?

Believe it or not, based on the pictures provided on their website, I can't tell which unit I should purchase as to me, the connections in the provided images do not look correct (lacking familiarity) and I don't want to get the wrong unit. Currently we're using a DSPeaker, 8033S II, Anti-Mode, REW, Audyssey, MultEQ XT based EQ solution. When I tried to correspond with miniDSP, Inc., customer service was not interested in helping me with my consumer based, ignorance caused confusion. In my opinion, I was receiving if-then, robotic style responses so I gave up on the miniDSP as a sonic solution.

Based on my above, it doesn't mean I think less of the miniDSP as a sonic solution just that my consumer based ignorance is keeping me from making an informed consumer based decision and in the spirit of full disclosure, I post my above.

As an aside, in the spirit of the thread's title which you authored, based on personal experience, I've come to the conclusion that in particular, our room would benefit by the addition of a third sub but in doing so the question morphs into, "When does the esoteric meet the reality of any issue?"

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Edited by BeeMan458 - 3/15/13 at 9:57am

Well, we don't know what his reference is for "sounds good". We don't have any "context" to compare what he thinks "sounds good" vs. what he thinks "sounds bad." For all we know, his room may sound like a disco with lots of BOOM and Sizzle, and he may think that sounds "good." (OP, please don't take offense. I am merely using your post as an example of the imprecise nature of subjective descriptions such as "sounds good.")

For that matter, we don't know *your* definition of what "sounds good." AFAIK, you've never posted what your system(s) are comprised of, or how you have them set up. More importantly, you've never posted any measurements of your system(s) that I'm aware of. How are we to know what "good" sound means to you? The only thing I do know about your listening preferences is that you've stated that don't prefer to listen at "loud" levels. Once again, that's a subjective statement and we have no context of what "loud" means to you. You may be satisfied with 30 Hz extension, (similar to the LF extension in most movie theaters), and less than Reference Level output. If so, that's fine for you. However, this would cloud your judgement about how to set up multi-subwoofer systems for ultimate performance. We can make a lot of things work at modest levels. It's only when ask our systems to produce prodigious levels that real performance comes into play.

Non-identical subs can't possibly work as synergistically as identical subs at levels were an inferior sub would hold back the performance of a superior sub. It's simply not possible.

Because non-identical subs will always have different performance characteristics, it will always be more difficult to integrate them into a "system".

For example... If you use a ported sub with a -3 dB point of 35 Hz, a roll-off of 24 dB per octave, a maximum output of 90 dB at 25 Hz and 10% THD at 25 Hz... in the same system with a sealed sub with a -3 dB point of 20 Hz, a roll-off of 12 dB per octave and a maximum output of 100 dB at 20 Hz, and 1% THD at 20 Hz, then the lesser, ported sub will clearly hold back the better sealed sub. You might be able to make the "system" work, and the sound might be "better" than the cheap, ported sub alone, but it will be nowhere near as good as the better, sealed sub would perform all by itself. The "system" might sound better up to about 93 dB, (or 3 dB above the limits of the lesser sub.) Beyond that, the "system" will be limited to the output/extension/distortion limits of the far inferior ported sub. You'll never be able to achieve the full output/extension of the better sub! Why bother getting a much more expensive sub and then hold it back with a cheaper, far inferior sub? In the same breath, why take the risk of destroying the lesser sub while trying to experience the output capabilities of the more potent sub?

OTOH...

If you use identical subs, they'll both have the same -3 dB point, the same roll-off below tune/resonance, the same maximum output, the same transient response, the same distortion/compression limits. Neither sub will hold the other back; in fact they will both add to the "system" limits, which will be *higher* than the individual limits of the individual subs. Neither sub will distort/compress before the other sub. (Of course, all this assumes that the user gain-matches and properly integrates the two identical subs.)

Bottom line... in a system where the subs are used at close to their performance limits, there is no way two non-identical subs can work as well as two identical subs, (at least not within any reasonable price/performance delta.). Even if the two non-identical subs are very close, one sub will always be inferior to the other sub in some aspect of performance, and it will hold the other sub back, and the overall system back, due to it's inferiority in that aspect.

You can claim all you want that you've made dissimilar subs work in various systems, but until you can post measurements that show the systems perform better with non-identical subs than with identical subs, and that the system limits are higher with non-identical subs, your claim is nothing more than your subjective opinion. That might work in the "Under $300" thread, but in the rest of the forum, we'll call BS.
(No one ever claimed it was necessary to match the subs to your speakers, so I don't see how this comparison relates to using different subs together. The principles involved in this are completely different.)

Rather than comparing surrounds that don't match your front speakers, the better comparison would be mixing a different left surround with a different right surround. For example, let's say you used a dipole right surround and a monopole left surround. The timbre-match, dispersion, sensitivity and bass extension of the left surround would be completely different than the right surround. This might "work" in the sense that you would have "sound" from each surround speaker, but it would hardly be considered an optimal solution. Of course, the more similar the left surround is to the right surround, the "better" it will work, but nothing will beat matching the surrounds with identical speakers. Similarly, using non-identical subwoofers can "work", but due to different LF extensions, roll-offs and outputs, it is hardly an optimal solution. The ideal solution will always be matched, identical subwoofers being sent a matched, identical signal.

Finally, something we can agree on... 3 identical subs will sound better than 2.

Now, whether 3 non-identical subs will sound better than two identical subs is a somewhat open question. IMO, for the most part, I don't think so, but some of it depends on the subs in question and it also depends on the ability of the integrator, the placement options and the room acoustics.

OTOH, whether 3 identical subs can sound better than 3 non-identical subs is not an open question. If the 3 identical subs are properly optimized, there is absolutely no doubt that their maximum potential is far higher than 3 non-identical subs.

To the OP:
If you are dead set on using three different subs together in one system, I suggest you try the technique of Geddes as related by Markus Mehlau: http://mehlau.net/audio/multisub_geddes/ If I were going to try to integrate 3 completely different subs into one system, that's the method I would use. Even at that, you'll need to be aware of the capabilities of the weakest sub in the group as it will be the limiting factor.

Craig
Edited by craig john - 3/15/13 at 3:54pm

True, but in most cases two dissimilar subs will sound better than one, and three dissimilar subs will sound better than two, assuming they aren't grossly mismatched. Three matched subs would usually be better, though.

Two dissimilar subs will sound better than the one lesser sub all by itself, no doubt.

Whether it will sound better than the better sub all by itself will depend on the subs in question, how they're set up and the room acoustics. If the lesser sub limits the better sub, then the overall system won't realize the full performance capabilities of the better sub. The FR will be improved, but the overall limits of the *system* will be limited to the capabilities of the lesser sub. So it depends on the goals of the user. If better FR is a higher priority than more output/deeper extension, then two mismatched subs could be better than using the single, better sub by itself. However, I think it's rare that people "upgrade" to a better sub with the intention of limiting it to the output capabilities and LF extension of their lesser sub. Yet, lots of people come on here all the time asking if they can still use their old sub with their new and upgraded mega-sub. Sure, they can do it, but they need to be aware of the tradeoffs involved.

Craig

I don't know if they ship to the EU, but a much more similar sub to your Epik would be the PSA XS30. It's a dual-opposed design with 15" drivers and a 725 watt amp. http://www.powersoundaudio.com/products/xs30 The company "principle" is Tom Vodhanel, who was the "V" in SVS. He's started his own company and there is a thread dedicated to their subs: http://www.avsforum.com/t/1372020/power-sound-audio-discussion-thread He's also a forum member and you could PM him for more info.

Another sub with a similar design is the Seaton Submersive HP. It uses the dual opposed design with 15" drivers and a 2,400 watt amp. It's a significantly stronger performer than the Epik and it is quite a bit more expensive, but it could be given consideration also. (Actually, the HP version is not currently available in the EU. Only a 1,000 watt amp is available in the EU at this time. Still, it's worth considering.) http://www.seaton-sound-forum.com/?forum=86963
The Submersive thread is here: http://www.avsforum.com/t/759877/seaton-sound-submersive1

Craig

If "looks" are paramount to quality of sound, one pays a bundle for this privilege as one can only play their system so loud and then it's no longer about sound quality and morphs into a contest (bragging rights) of how loud can one make their subwoofer system go. The louder one's system goes, the fewer people are able to co-enjoy the system which creates a narrowing field of participation.

The point, one may have enough headroom to get 120dB or more out of their system but is that what one wants and is that what visitors and loved ones want to experience and is that what the mixing engineer spec'd the sound track for?

If the answer is yes, that's what they want, cool but when evaluating subwoofer choices, one needs to take my above into serious consideration; that above a certain point, they've crossed the line of rational and have entered the world of irrational esoteric behavior and how loud can one's system go? And in truth, there's nothing wrong going there, it's just that some have trouble admitting to themselves and others, that's their purpose as others still are driven out of the listening space due to unacceptably loud listening volumes.

The point of the above? Will the spouse sit next to the assembler of this uber cool subwoofer system and enjoy movies together or, in the end, is the spouse and family being driven out of the listening room and the assembler of the subwoofer system ends up watching movies by themselves?

FWIW, having to personally deal with the WAF, this is an issue I've put a great amount of time exploring and so far, based on in depth research on sound levels and what is really listened to in movie theaters, roughly 0.01% of movie based content is >90dB and THX reference is 85dB - 105dB for speakers and 115dB capability for the subwoofer system because of hearing based disparities between high and low frequencies but sound engineers rarely mix for an expected peak above 90dB.

In our living room, the loudest, calibrated main volume control (MVC) set to +/- 0, was a SPL recorded at a paltry 100dB. Maybe it should have been louder and the problem is the AVR and the need for a separate amplifier which is being budgeted for as I post the above for perspective purposes.

In response to the question regarding three subs being better than two, it's not about playing it loud but about the smoothing of peaks and valleys created by interacting sound waves; reinforcement and cancellation so more listening positions are exposed to ideal listening conditions. It's not just about the main listening position (MLP) but the listening experience is about everybody who sits, watches and "ENJOYS" the home theater listening experience; clear, consist, easily understood dialogue "AND" full impact of the Low Frequency Effects (LFE) channel with emphasis on "effects."

The overall point, I went to the movie house (I'm sure we all did or do) as a form of communal entertainment and enjoyed the company of others. I didn't put together a quality home entertainment system so I could drive everybody away. Just saying and I don't see much conversation of this kind hence why I'm bringing these points up as once the WAF enters the equation, one needs to seriously take into consideration the above or they'll quickly become a viewing audience of one.

An aside, nobody has sympathy for the individual who's being deprived of loud because everybody is to busy having sympathy for the person holding their temples because it's too loud and the last thing any husband wants is their wife writing a "Dear Ann Landers" letter stating their husband plays the volume too loud as not too many people are sympathetically into "loud." And just so there's no chance of my intentions and my above comments being misinterpreted, if someone wants to blow a million dollars on their subwoofer system alone, I support and encourage their ability/desire to do so as I too like it loud. But in our case, the WAF is a powerful force indeed. Just saying.

I hope the above shared personal insight helps with your buying decision and continued good relations with your wife.

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Edited by BeeMan458 - 3/17/13 at 12:29pm

Your comments on WAF are based on YOUR wife. Some other wives, mine included, are much more enthusiastic about the HT. My wife helped me design mine. She picked colors and carpet, and she made the curtains hung over the acoustic treatments in the front of the room:



She also helped me design and make the acoustic panels:



She also loves to listen to the system at "full throat." We recently watched Prometheus at -3. My wife enjoyed it every bit as much as I did. In fact, she noticed that I didn't have the Crowson tactile actuators on. After the opening scene, she said, "I don't feel the shakers. Are they on?" Sure enough, I had turned them off to do some measurements and forgot to turn them back on. She actually suggested that I start the movie over so we could experience that scene with the shakers on.

We also recently watched Total Recall. I started out with it at -6 and my wife asked me to turn it UP. We settled on -3.

Bottom line, WAF is specific to the W involved.

More importantly, the ability to listen to the system at full Reference Level is dependent on the capabilities and headroom of the system. If the system is struggling, compressing and distorting at RL, then it won't be an enjoyable experience to listen at RL. However, if the system has plenty of headroom and is just loafing along at RL, it won't even sound that loud. Here is what another forum member said about my system after spending an afternoon at my place recently:

So, I'm not driving anyone out of my room or hurting anyone's ears when I turn the volume up in my system. Virtually everyone who has experienced my system says the same kinds of things that BrolicBeast said.

Oh, and your comment about the quantity of content made for full RL is way off base. Many, many current movies are using the full bandwidth available on the BluRay format. You just need a system capable of reproducing it without strain in order to be able to enjoy it at the levels it was recorded.

Craig

Repeating myself:





I continually edit for fullness and accuracy of comment and between your above and my edit, this edit had been added.


The above comments of this post has been edited many time for fullness and accuracy of comment and expected will be amended several more times.

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Edited by BeeMan458 - 3/17/13 at 12:30pm

Now I'm not a sound mixer (working on it :DD) but this quote "roughly 0.01% of movie based content is >90dB" is hard to believe considering at reference, dialogue is at about 85dB...Is my logic flawed here? Craig?

-Kevin

This is the study I'm citing in my comments regarding 0.01% of the time.

"However, this is put into context when looking at the exceedance levels. No film exceeded 90 dB(A) for more than 5% of the time, which varied between 6 and 8 minutes. With the exception of The Siege, no film exceeded 90 dB(A) for more than 1% of the time, which was approximately 1 to 1.5 minutes. Furthermore, for all films except The Siege, sound levels exceeded 90 to 95 dB(A) for only 0.01% of the time i.e. less than 10 seconds. The Siege exceeded 90 dB(A) for about 90 seconds. All the films had a number of scenes with explosions and gunfire, however for a large proportion of the time the noise levels (L Aeq ) were below 75 dB(A). This is illustrated in [Figure - 1]."

I did a meta study, reading many studies (some empirical and some informational) not just one or two with the purpose to corroborate a personal bias as the intent of the personal study was to widen my understanding on the matter as opposed to serving a bias to satisfy my wife. I'm looking at empirical readings of movie theaters, MPAA standards in force and what happens when the rubber meets the road in a movie theater, not esoteric based comments on an esoteric based forum. What I find, folks don't like having their Jones challenged and when that happens, out comes the defense forces. The studies are in, this "IS" a cooked bird.

My comments are accurate and posted in passing so one who's a noob to the matter gets countering information so when they buy, they're doing so, fully informed, with both sides of the conversation. Again, if one wants to blow their life's savings on anything that makes them happy, they're welcome to but when one is limited by WAF, one needs "rational" based information to base their buying decision on as to buying two or three subs and what are the realities of diminishing returns, when compared to real world information.

From all I've read, there's sound stage mixing standards and there's playback standards and research is showing the two are not equally meeting in the middle.

Here's a monologue discussion on the matter.


"In the opinions of industry audio professionals that Millimeter spoke with, such thinking is seriously flawed. They suggest that clients hell-bent on cranking up the volume are harming the art of sound mixing, endangering the ears of industry professionals, and fooling themselves since few audiences will ever hear the sound tracks as loud as the filmmakers intended.

"What is happening is that many of these film sound tracks are coming to theaters so hot that theater officials have to turn down the volume," explains John Ross, a veteran film mixer and president of Digital Sound & Picture, Los Angeles. "So mixing film sound real hot ends up self-defeating because you end up with an unbalanced mix in the theater with dialogue sometimes inaudible."

Because of the issues surrounding film volume, many sound pros are currently taking part in an informal, but growing, debate over how to safely retain creative control over the mix."

This point should be noted:

"A lot of these mixes go above 100dB, even up to 108 or 110," says Ted Hall, a senior mixer at POP Sound, Santa Monica. "We don't have a lot of that in our studio, because we tend to work on mid-range budget films and indie films, but many major features out there are doing this. That is definitely a big concern for people working in our industry because listening to those levels 10 to 12 hours a day will definitely hurt your ears."

"Take Precautions As Letessier says, "When your hearing is gone, it's gone." That is why some experienced mixers suggest the selective use of professional earplugs and taking frequent breaks. Ironically, the march of digital technology has altered parts of the basic methodology of sound mixing to the point where traditional opportunities to take such breaks no longer exist."

"We've lost all those short breaks we used to get with the changeover from one film reel to another," points out Christopher Boyes, a sound designer and mixer at Skywalker Sound in San Rafael, California. "It's all digital now. You used to get five to 10 minutes of quiet while the reels were switched. Now, you instantly pop to any section of a film with the press of a button."

Some may not like the above but the consumer is the final arbiter of everything and if the consumer is wanting the volume turned down, then it means the mixing engineers are not getting the message and I find the article to be an overall scathing indictment of the mixing industry at large. One is not being honest if they're intentionally leaving out the facts.

I'll stop responding to those who disagree who are now dragging thing's off topic with their argument as opposed to posting to the OP. At this point, I'll only respond to the OP.

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Edited by BeeMan458 - 3/18/13 at 3:53am

I use to like what Pioneer added at the end of there manuals back in the day and not sure if they still do but its something many years back I took to heart, it simply listed the decibel levels of various things and stated

" We want you listening for a lifetime"

Do you not see the contradictions in your "evidence"?

Craig

Damn, between honeybear not letting you get any new subs, daily rew tests and all these fights you have on here,
I think you are harshing your own gig. Have a nice hamburguesa, wheeze some juice, and mellow out bud-dy.
We're all just talking here.

My wife likes big bass. She hates the boxes big bass comes in. She also doesn't like it loud but when she feels the bass, like most, she lights up. Now the question morphs into; how to get big bass, in a little box, that lights the room, but doesn't blow out the windows or my wife's ear drums and get me put out on the streets?

For the price, two of these boxes by Rythmik, seems to be the best I can find that satisfies the above question.

From the above, the price rises dramatically as now one gets into Funk Audio gear; looks and performance.

The next question becomes, is a single Funk Audio, 18.0C going give the same overall, room smoothing performance of two Rythmik E15's or is one eventually driven into buying two or three to smooth the bass response to the room's acoustics?

In a sense, the above question is rhetorical as more subs, up to four, is better than one.

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Edited by BeeMan458 - 3/18/13 at 6:03am