ghulamr, You don't mention your budget but there's a solution that'll give you state of the art bass for both 2-ch and ht. It's called the Audio Kinesis Swarm distributed bass array system. Here's a review of it from The Absolute Sound magazine: http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/ It's not cheap at $3,000 for the 4
(12" x 23" x 12")
subs and the 1,000 watt class AB amp that powers the 4 ohm subs. But I know it'll give you sota bass for music and ht because I've been using this bass system in my 23 x16 foot room for about 2 years now and it provides the best bass I've ever heard in my system. I believe it would work very well, even in a room as large as yours, since it was designed for any size rooms from residential sized rooms to commercial club sized rooms. Other big benefits of this system are that it provides great bass response throughout the entire room, not just at a predetermined sweet spot, and it requires no mics or room correction software or hardware, just some included equalization if you have some bass 'slap echo' present caused by bass sound waves bouncing between the floor and ceiling. I run my subs configured as ported but the system does come supplied with port plugs if you prefer to configure the subs as sealed. I compared ported vs sealed in my room and thought the ported configuration sounded better for both music and ht. If $3K exceeds your budget, it's possible to create your own custom distributed bass array system using any 4 subs of your choice. The only requirements are that you need to use at least 4 subs, although 3 may be sufficient in some rooms, and follow the specific sequential sub positioning procedure provided (which I can detail for you if you're interested.). As the TAS review mentions, however, why bother when the Swarm system works so well and is so reasonably priced. But it is true that the better the sub quality, the better the sound quality. Tim |
ghulamr,
Are you ruling out a Swarm type bass system?
If it's too expensive for you, I understand. Prior to the Swarm, I tried multiple brands and models of single and dual sub configurations and positions in my room ( Velodyne, REL, JL, Hsu, Klipsch, Polk, B&W, Theile and a few others) and none performed as well as the Swarm.
My main speakers and center ch are Magnepans, which are notoriously difficult to integrate subs with. The Swarm system was the only system I tried that blended seamlessly with the Magnepans for music and still delivered the bass impact I wanted for ht. It truly is a state of the art bass system.
I'm unaware of any single or dual sub setup using conventional subs, at any size or price, that can match the performance of the 4 moderately sized Swarm subs properly positioned. I do believe, though, that utilizing 4 of almost any top line conventional subs properly positioned in a distributed bass array system would likely outperform the Swarm subs. I've never personally tried this but I know it would cost about 4x or more than the $3K price of the Swarm and probably only deliver marginal bass response improvements.
The 4 sub distributed bass array system is the result of years of research on in-room bass response conducted mainly by 2 PHDs in acoustical engineering, Dr. Earl Geddes and Dr. Floyd OToole. Google their names if you'd like to learn more about their experiments, conclusions and White Papers.
My intention is to share my many years of experience and knowledge trying to achieve the same bass response it seems you're now searching for. I have no financial or other interests with Audio Kinesis/Swarm other than purchasing their bass system and knowing how well it works in my system.
My opinion is that the single 15 x18 x20 sub that you are looking and hoping for does not exist. Sorry, but it's as simple as that.
The $3K Swarm system is the least expensive solution I'm aware of that will provide you with the bass performance you described.
Tim |
batman1971,
The REL Storm III sub woofer consists of a single 10 inch (250mm) long throw bass driver,not 4 drivers, that faces downward in a large cabinet (
16.5"w x 24.5"h x 13"d; 60 pound). It is powered by an internal 150 watt amp, not a 1,000 watt amp.
Dsp and room correction can be used with the Swarm bass system but is not required or necessary.
Tim |
I don't really understand what is meant by pressurizing the room. Can anyone please explain this physical process and its benefits?
I do, however, understand many of the terms and concepts involved related to achieving very good bass response in a given room.
A 20Hz deep bass tone sound wave is 56.5 ft. long. Since few people listen to music in a room that has a dimension that is that large, it means the 56.5 ft. sound wave of 20 Hz is emitted into the room and, once it hits a room boundary (floor, wall, ceiling) or other solid object in the room, it will reflect or bounce off these surfaces (at predictable angles) and it then continues on its new trajectory until it encounters another solid surface and reflects again. This process continues until the long sound wave runs out of energy.
How one perceives this long 20Hz sound wave depends on exactly where your head/ears are positioned within the room and whether the direct sound wave from the sub arrives at your ears first or if a reflection of the direct sound wave arrives first. To further complicate matters, the most likely scenario is that your ears will be detecting the direct sound waves and reflected (indirect) sound waves within milliseconds of each other which alters the bass frequency and detail perceived.
Also, as longer bass sound waves continue to bounce off of room boundaries they inevitably collide with one another. These collisions cause what are called 'room modes', which result in exaggerated, attenuated or even negated perceived bass at specific locations in the room. The more bass modes in a room, the poorer the perceived bass and vice versa.
Through their research and experiments the acoustical engineers mentioned on one of my previous posts on this thread, doctors Geddes and O'Toole, discovered that bass room modes decrease in direct proportion to the number of subs in a given room.
The more subs in a given room, the fewer bass modes present.
Of course, they realized that there's a practical limit to the number of subs that individuals' significant others will find acceptable in a home environment.
Interestingly, however, they found that when 4 subs are deployed in a given room and located following a specific sequential procedure (which I can detail in another post), that the vast majority of the bass room modes are eliminated or considerably lessened in their affect. This is the basis for the AK Swarm bass system and the reason it consists of 4 subs.
Without any doubt, the Swarm bass system by a wide margin provides the best bass response in my room/system that I've ever used, much better than any of the numerous single and dual sub configurations I've ever used.
The improvements I notice are an effortless quality to the bass in which it will go as deep, dynamic and powerful as the source content calls for while also being very articulate and detailed in the bass that allows for clear recognition of the instruments being played and small variations of pitch and tempo. I believe both these qualities are unique to, and possible with, the Swarm due to its use of relatively smaller 10" sub woofer drivers and the fact there are 4 and not just 1 or 2 in the room.
I doubt it's a coincidence that none of my previous 1 and 2 sub bass configurations could match this high level of bass performance of the Swarm.
Tim
|
seasdiamond:
"
Wouldn’t it be easier to just get 2 subs and run room correction than go 4 subs?"
Yes, many users might be satisfied with 2 subs room corrected to provide good bass response at a single sweet spot in their room and it would be certainly easier.
I've helped several friends and family members with their smaller music and ht systems, usually just an a/v receiver, 3-5 spkrs and 1-2 subs.
They usually want good sound for 1-2 people from a sofa facing an hdtv. I've positioned the mic at the center of the sofa and this has resulted in decent bass response for anyone sitting on the sofa but poor bass response at other seating positions in the room.
Makes sense, right? Room correction is only capable of optimizing bass response from the single spot in the room you are giving it frequency response and volume data from (wherever you decide to position the mic).
I haven't been overly impressed with the results of the limited room correction systems I've utilized. I've found I can easily attain better bass response results by positioning the subs by ear and trial and error, though I am able to get the best results using 2 subs rather than just 1.
In my system, I was looking to get very good bass response for music and ht at all 7 seating positions spread around the perimeter of my 23 x 16 foot room. I positioned all 4 subs sequentially by ear and concealed all the wiring by running it in the crawl space below my living room. My best sounding sub configuration turned out to be 2 subs along the front 16' wall and 1-2 feet in from the front corners along with one sub along each 23' side wall, about 1-2 feet away from the rear corners.
I've never had a room frequency response analysis done for my room but bass response is exceptionally and consistently good throughout the entire room.
So, in my experience and to answer your question, 2 subs with room correction do not equal the bass performance quality of 4 subs either with or without room correction. 4 subs will provide an increase in a sense of effortless bass with increased detail and improved bass dynamics. These improvements will also be present throughout the entire room, not just at a predetermined sweet spot.
Each individual needs to decide whether or not these bass improvements are important to them.
Tim
|
ghulamr,
It seems like you've decided to go with a single sub in your system. You'll still be able to get good bass response with a single sub if you're willing to accept just having a single bass sweet spot at your listening seat.
I'd suggest looking at Monoprice's sub offerings and you could buy 2, or even 4, for about your $600 budget. These will not go as deep as the Earthquake or NHT but I think having 2 or more 12" subs will give better results than a single 15" sub.
Remember, all of these subs are run in mono and you'll get the dual benefits of cumulative bass output(you'll perceive the bass as more powerful but will not be able to pinpoint where it's coming from) and the reduction of room modes that begins when you have 2 or more subs in a given room (bass will sound smoother and more natural). Also, neither sub is being over-driven.
I know in any room, 2 subs will provide better bass performance than 1 sub, 3 better than 2 and 4 will provide exceptional bass response. I can advise you on proper positioning when using any quantity of subs from 1 to 4 and in between.
For the optimum positioning of 1 sub in your room, I'd recommend placing the sub at your listening position and play some music with good and repetitive bass. Then, starting at the front right corner of your room, slowly walk along the perimeter of your room counter-clockwise until the bass sounds best to you. When you find this exact spot, place your sub at this position.
Next, sit at your listening seat and replay the same music. If the bass sounds just as good to you, then you've successfully positioned your sub. If it doesn't sound just as good, you can either make small adjustments to the sub's position through trial and error until it does sound good to you or start the process all over again from the beginning.
Tim
|
millercarbon:
"
Like, we all talk about this stuff with regard to bass, when in reality its not only bass but all frequencies. With bass its in your face obvious. But its across the board."
Hello millercarbon,
From your last post, I can tell you have a good understanding of all this stuff.
I agree with your comment that all frequencies are important in a room for good sound reproduction. I've reached the conclusion that, since bass frequencies behave differently than midrange and treble frequencies in any room mainly due to the large differences in the length of their sound waves, it's best to treat them separately.
I've learned to get the bass response functioning properly first since it's the most difficult to get it sounding good in most rooms due to the very long lengths of low frequency sound waves. I think you agree with me that a precisely positioned 4 sub distributed bass array is the best method of achieving this. There are no mics, room correction software or hardware, parametric equalization and room treatments required. The complete Audio Kinesis Swarm or Debra bass systems work very well, come with everything needed and are relatively inexpensive but any 4 subs will work as well or better as long as they're positioned properly, although they'll cost more.
Once the bass is sounding good, the next step is to get the remaining midrange and treble frequencies sounding good which involve different room considerations due to the much shorter sound wave lengths involved. These frequencies also reflect off room boundaries but colliding midrange and treble sound waves are so numerous they're normally perceived as an 'airy' quality. The most important factor for good stereo imaging is that the direct, non-reflected sound waves from both the l + r speaker reaches the ears first before any reflected sound waves do. Room treatments, that absorb or redirect first reflections, are proven methods to ensure this happens at the selected listening position. The later reflected midrange and treble sound waves arrive at the listening position, the better.
But I'll refrain from further discussing the proper speaker and room configurations for good midrange and treble response at the listening position since most reading this are likely already knowledgeable about them.
Tim |
millercarbon,
Just callin' em like I see'em. I'm just enlightening guhlamr to some pertinent truths. It's his money, system and choice. Besides, I'm almost certain he'll be happier with multiple 12" subs than a single 15" sub.
Everybody also knows I'm the chump responsible for guhlamr's happiness. And let me tell you, millercarbon, it's a lot of gosh darn constant pressure!
I'm just hoping I don't blow a gasket,
Tim |
"
Can you help shed some light on how you best play 2 channel music with the Swarm system? I understand playing HT you can connect to the processor LFE - but how to best play 2 channel?
Currently I play my 2 channel using the Benchmark DAC as preamp powered by Simaudio W5 amp driving VR4 speakers."
Hi ghulamr,
The supplied class AB amp for the Swarm has a single unbalanced rca input for LFE and separate L+R rca inputs for connecting the outputs of a preamp or your Benchmark DAC.
I'm semi-familiar with Benchmark DACs and believe most models have both XLR and rca L+R outputs. I'm not certain whether your model has both but I'll assume it does until you tell me otherwise.
I know the Simaudio W5 amps usually have 2 sets of rca inputs, one istandard set and one set with inverted phase.
If the above is accurate, you're likely already using the Benchmark's rca outputs to connect to your amp so there would be 2 options:
Option#1: Use the Benchmark's XLR outputs and connect to the Swarm amp using either a pair of cables with XLR connections on one end and rca connectors on the other or use XLR to female rca jack adapters and connect to the Swarm amp using a pair of rca cables.
Option#2: Use the Benchmark's rca outputs and use 2 rca y-adapters (male rca plug to two rca jacks) with one connected to the right channel output and one to the left channel output. Then use pairs of rca cables to reconnect the amp and connect to the Swarm amp.
I'm glad you posted again and haven't ruled out the Swarm just yet. I can directly relate to your search since I was searching about 4 years ago for the same thing; very good bass response in my system that integrates seamlessly with my main speakers, capable of being fast and articulate enough for music while still being powerful and dynamic enough for both music and ht content.
I know the Swarm may be a bit more expensive than you were expecting to pay for really good bass response in your system/room because, again, I initially felt the exact same way. When I began my search I recall thinking I'd probably wind up buying 1 of the several newer self-powered subs then on the market, experiment with it for a few weeks and return it if it didn't work out well. If it did work well, I could always try a 2nd one and determine if that performed even better.
However, I then decided I needed to first become more knowledgeable about bass room acoustics and the best methods to achieve very good in-room bass response. After a few weeks of internet research. I learned about the distributed bass array concept, read the very positive TAS review of the commercially available complete kit example based on this concept (the AK Swarm system) and called AK.
At this point, I was still hesitant mainly because it sounded too good to be true and I considered the $3K price a bit steep. But, after numerous phone and email conversations with AK dealer,James Romeyn, in Utah, I gradually gained confidence and, when he offered a free 4 week in-home trial, I decided to buy the system.
It took about half a Saturday for a buddy and I to properly install it but I still consider the Swarm the best system upgrade I've ever made. I've used it for about 4 yrs now, and I still consistently have feelings and thoughts about how fortunate and grateful I am that I decided to give it a try. I don't think I can overstate how well the Swarm system performs in my room/system. I justified the price by equated it to about the same or less than the price of 2 very good conventional subs.
Please don't hesitate asking if you have any further questions.
Tim |
guhlamr,
I forgot to mention, I wasn’t aware your amp had both XLR and rca L+R inputs. This is a good thing since I think you should be able to keep the L+R outputs of your DAC connected to the L+R inputs on your amp via XLR cables.
Now I just need to take a closer look at your DAC and sources for their connections.
Tim |
" but I really hope I am going about this incorrectly and there is a better/cleaner way to connect both HT and dedicated listening for Swarm system since you can only connect LFE or the RCA line in but not both at the same time. LFE uses the pre-processor cross over and RCA line in uses the subwoofers.
Hi guhlamr,
To help you find a good solution, I need to know the model number of your Benchmark DAC, the music source you use and how do you connect this source’s output to your DAC (which exact input you use?).
Just to clarify, you stated: "LFE uses the pre-processor cross over and RCA line in uses the subwoofers."
This is correct for the inputs on the Swarm sub amp. The bass cross-over setting for the LFE output would be set on your AV7005 and the Swarm amp’s low-pass onboard cross-over is bypassed. For music, the bass cross-over frequency is set using the Swarm amp's front panel control.
You also stated: " you can only connect LFE or the RCA line in but not both at the same time."
This is incorrect for the inputs on the Swarm sub amp. You can connect both and the Swarm amp will automatically detect which input is active and amplify it. This is how my system is setup. I only play one at a time, either music or ht and it automatically sends the source I’m playing to the subs.
Thanks,
Tim |
Hi guhlamr,
I also have an Oppo BDP-105 in my system. Excellent and versatile machine that has exceptional audio performance.
I also use a 2TB external hard drive that contains ripped copies of all my cds and some other hi-res 24/bit/96Khz Flac files (great minds?).
Your description of hook-up details looks good to me with one exception:
"
the only manual change between HT and dedicated listening will be to remove the XLR inputs from Simaudio and connect the RCA input from Marantz every time I set it up for HT (have to borrow the 2 channel amp). I can use a switch box for that eventually. "
Why not just connect the front L+R mains outputs from the Marantz to the L+R inputs on the Simaudio amp permanently? You're only playing music or HT and never both at the same time, right? This would eliminate any need for unplugging/plugging of connections and switching would be automatic and seamless.
If there's no switch on the back of the Simaudio amp to select XLR or rca inputs, this indicates that both inputs are active and the unit will just amplify the signals that are inputted. I doubt it would attempt to amplify both XLR and rca signals if they are present at the same time. But it really doesn't matter since you only play 1 at a time (music or HT) there will only be either XLR or rca signals inputted to the amp at a time and not both.
I also wanted to suggest a change to your HT setup that I've made in my system that you may not have yet considered. This is just an optional change to your system mainly focused on simplification and streamlining.
I believe you could remove the Marantz AV7005 from your system without a performance penalty. You're currently using two high quality prepros in your system, the Oppo and the Marantz. Unless the Marantz has a capability that the Oppo lacks that I'm unaware of, there really is no need for this redundancy.
I think we both use a 5.1 surround for HT in our 5.1 HT systems (5.4 with the Swarm?). You could connect your 3-ch amp directly to the Oppo 105, it has a very high quality surroud sound processor that decodes up to 7.1 ( contained on a separate/isolated audio board using multiple high quality and expensive Saber 9018 dac chips), the cross over frequency can be set on the Oppo and its LFE output can be connected to the LFE input on the Swarm amp.
I eliminated a Parasound AV2500 prepro from my system and replaced it with the Oppo 105. I thought the surround performance improved without a downside but YMMV. You could experiment and decide for yourself.
For streaming, I'm just using Spotify on my laptop connected to a separate dac,3 watt class A headphone amp and good phones. But I think I should probably be receiving advice on this rather than giving it.
Overall, you're plan sounds very good to me with the exception of switching inputs on your amp.
Tim
|
Duke/Audio Kinesis,
Thank you for your unexpected but very informative and interesting contributions to this thread.
I think many have the somewhat mistaken belief that attaining good in-room bass response is simply a matter of using 1 or 2 subs of a particular, or 'right', brand and model in their systems.
My experience is that 1 or 2 good subs can achieve good bass response at one specific sweet spot in most rooms but this results in inconsistent bass response throughout the remainder of the room, heard at various specific spots in the room as bass peaks, nulls and even bass absence. For those unconcerned with good bass response being restricted to a specific sweet spot, I think 1 or 2 subs properly located can be a satisfying solution.
The distributed bass array concept of 4 subs properly positioned definitely has the advantage of producing very good bass response throughout the entire room for those that require it.
However, I've noticed other benefits to the bass quality that were unexpected that I'm theorizing are only possible due to there being 4 subs dispersed throughout the room and their cumulative affect.
My best description is the bass in my room became more agile or flexible in the sense it can faithfully reproduce whatever bass is dictated by the source material, whether it's music or HT. It can be finely detailed on music that allows for the easy identifying of the different bass instruments being played, following the separate bass lines and also the small changes in pitch, tone and volume of each instrument. The bass can also be powerful and delivered with sudden impact which helps convey the large dynamics of live music and the low frequency effects on HT.
My main point is that a distributed bass array system, whether the Swarm or a custom setup, has more benefits than just good bass response throughout the entire room, it also elevates the quality of that bass to state of the art. I've never been able to achieve this level of bass quality in my system with 1 or 2 subs.
Tim
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Duke Lejeun:
"
Thank you very much Tim. I find your posts quite educational, as I think you have more real-world experience than I do, and you have paid very close attention to your experiences. And you write very well! "
Hi Duke,
Thanks for the kind words. I've done quite a bit of research on low bass room acoustics, in-room behavior of the longer bass sound waves and sub woofers in general. But I don't consider myself an expert, just an enthusiast who has learned enough to be dangerous.
My main motivation was trying to supplement the less than stellar bass produced from my main speakers, a pair of Magnepan 2.7QR 6 x 2 ft. panels that bottom out at 37Hz. These speakers have excellent mid-range and treble response but I knew my system needed better low bass response. I also knew that integrating subs with electrostatic and planar speakers seamlessly was considered difficult by many.
I began my journey searching for good bass response by using a single large M&K passive sub with a 12" driver powered by a separate class AB 150 watt amp.and later added a 2nd 10" self-powered sub. I'd describe the bass quality of both of these initial tests as better suited for HT than music. It was relatively easy to position the sub and subs so that the bass sounded best at my listening position. After adding the 2nd sub, I perceived the bass as more detailed and smoother but it continued to seem disconnected and not well integrated with my main speakers on music.
Since buying and properly installing the AK Debra bass system, I now consider my journey searching for good bass response completed. I'm not going to describe again how well the distributed bass array concept, whether the AK Swarm, AK Debra or a custom setup, actually works but instead just state I now consider my system's bass response for both music and HT as state of the art.
I believe this concept will work equally well in any room, with any speakers and that any skeptic would be convinced once they auditioned a properly setup system.
My sole intention is just to share the word about an exceptional solution.
Tim |
Hi ghulamr, You already have a very good system with high quality speakers that can reproduce very deep bass well. Can you tell me exactly what qualities you'd like to improve on the bass of your system? I just read a very good review on your Von Shwiekert VR4 MKII speakers on Dagogo.com. In the review, he mentions bi-amping them using a pair of class D 200 watt Channel Island D-200 mono blocks on the bass modules with very good results. The D-200 monos are no longer made but there are many very good high powered class D amps that could be used instead. Class D amps are often used to drive subs because they're small, powerful,have low very low levels of distortion, have very high damping factors and are relatively less expensive. Would you prefer to try this out before sub woofers? Here's a link to the Dagogo review: www.dagogo.com/channel-island-audio-plc-1-d-200-class-d-monoblock-amplifiers-and-xdc-2-ac-enhancing-... If not, I think you have 2 options for setting up a distributed bass array system in your room: Opt#1- Custom DBA: Use your existing pair of VR4 bass modules as sub#1 and sub#2 of the 4 subs required. This option has 2 variations since you would need to buy either A. 2 passive subs of your choice as sub#3 and #4 and the Dayton SA-1000 class AB 1KW amp used by the Swarm ($419 at Parts Express) or a class D 4 ch amp to drive all 4. Or, B. 2 amplified subs of your choice as sub#3 and #4 and either keep your current setup of not bi-amping your VR4s or biamp them if you'd like. Opt#2- AK Swarm or Debra DBA: Keep your existing system as is and just buy and add the Swarm or Debra complete system with 4 subs and the class AB amp to drive them. No matter which option you choose, I can help you with the proper setup procedure and any additional subs or amps you'd need. Opt#2, since it would actually consist of 6 subs in your room- the 4 Swarm subs plus the 2 VR4 bass modules) would likely provide the best quality bass and most bass (but controllable with the overall system volume control on the Swarm amp). Please let me know your thoughts on this and removing the AV7005 from your system. Tim
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phusis:
"I find the bass-being-omnidirectional claim too categorial in not factoring in the importance of ambient information aided via a stereo signal, below 80Hz as well."
Hello phusis,
I partially agree with your statement but, based on my experience, I think you have the cause and effect reversed. I know this is a subtle difference but I believe it’s important so I’ll do my best to explain.
First, I believe bass below about 80Hz is omnidirectional (that is, humans cannot perceive exactly where the bass sound is coming from.) Whether you configure 2 subs in a stereo or mono configuration, there is no ambient information existing on bass from about 80Hz and lower.
However, musical signals at or above about 80Hz are directional (that is, humans can perceive exactly where these sounds are coming from.)
I think the critical factor in determining exactly where bass sounds are coming from are the harmonics of the bass notes. For example, a fundamental bass note at 40Hz will produce harmonics at 80, 120, 160, 200, etc. Hz. Once these harmonics exceed about 80Hz, humans can perceive exactly where the sound is coming from. At this point, I think our brains take over and associate the multiple harmonics with the 40Hz fundamental note and the location it’s coming from.
So, I believe there is important bass ambient information aided via a stereo signal but none below 80Hz. Fundamental bass notes below about 80Hz are omnidirectional but the bass note’s fundamentals above about 80Hz are directional and are clues to where the fundamental bass note is coming from.
I believe the above based on my configuration and setup of my own system. I think the bass is the hardest to get right in any room/system so I do that first.
I use 4 subs (each is 28"hx12"dx14"w and weighs 40 lbs) all run in mono and powered by a separate 1K watt class AB amp with the cutoff frequency set at 50Hz. My room is 23’x16’x8’. My hdtv, system rack and components are located and centered along the front 16’ wall. My listening chair is located and centered along the opposite rear 16’ wall.
I optimize the bass at my listening seat by playing music containing good and repetitive bass, placing sub#1 at my seat and walking around the perimeter of my room in a counter-clockwise direction beginning at the front right corner of my room. I walk slowly along the front 16’ wall until I find the exact spot that the bass sounds best to me. Once determined, I relocate sub#1 to that exact position.
I then place sub#2 at my seat and continue walking slowly from sub#1 until the bass sounds best to me. Once determined, I relocate sub#2 to that exact position. This process is sequentially followed until all 4 subs are optimally positioned.
Last, I sit in my listening seat, replay the music with good bass and verify that the bass sounds very good. It’s important to mention that while the bass sounds exceptionally good at this point, I could not determine where the bass was coming from even though there was a sub on each 23’ wall with my listening seat in the middle of the rear 16’ wall between them and 2 subs located along the front 16’ wall.
Next, I optimally position my main L+R Magnepan 2.7QR panels along the front 16’ wall, about 8’ apart and each about 4’ away from this wall into the room, in relation to my listening seat and playing full range but rated bass down to only 37Hz.
Replaying the same music now heard in full range, everything becomes coherent and well integrated. There is a wide and dep soundstage illusion.
My main point being, with the benefit of now hearing the bass harmonics above about 80Hz, I could now determine where the instruments producing the deep bass notes below about 80Hz were coming from within this soundstage illusion. I believe hearing the deep bass harmonics above 80 Hz enables this no matter how many subs are used in a system.
Sorry this was so long but I find this a difficult concept to explain without a lot of detail. I hope I was successful.
Tim
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Hello guhlamr,
Congratulations, the JL Audio fathom f112 sub is an excellent choice. It's heavy at 115 lbs, solid, has a powerful class D amp, comes with a mic and room correction and the 12" driver should be very good for music and ht. Plus at $1,200, you got a great deal. Good job.
For setup, I'd still suggest placing it at your listening seat, playing the demo mode on the JL and walking around your room perimeter to find the best spot to locate it. The bass will probably sound exaggerated in the corners when you do this walk around. Once this is done, you can run the auto room correction to fine tune the bass response at your listening position even further.
The last step is finding the right crossover frequency that works well for music and ht. My suggestion is to set this frequency as low as possible while still sounding good to you. Remember, the sub is there to provide good bass impact when the content calls for it, the goal is not to constantly hear it. This is what is meant by 'seamless integration' with your main speakers.
Enjoy,
Tim
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guhlamr and gillatgh,
While your room (22x22x8) is larger than gillatgh’s room (15x22x8) and you’re both using only a single high quality sub, you’ll both find that you can optimize bass response at a single position (your chosen listening position) in your rooms provided the sub is properly positioned within the room in relation to your listening position. I detailed the procedure for properly locating a single sub in my last post.
The compromise of using only 1 sub in a room is that bass response will be poor at numerous other locations in the room. This will be obvious by just walking around the room after optimizing the bass at your listening seat. You’ll notice that at various spots in the room the bass will sound exaggerated, attenuated and even nonexistent. These spots of poor bass are the result of ’Bass Modes’ existing at these spots in the room.
Bass modes occur because bass sound waves launched from a sub are very long (a 30Hz sound wave is 37.66 ft long, a 20Hz wave is 56.5 ft long) and these long waves continue to reflect or bounce off room boundaries (walls, ceiling and floor) until they run out of energy.
The points where these reflected bass sound waves meet or collide are called bass modes. When 2 sound waves reinforce each other, the bass will be perceived as exaggerated. When 2 sound waves meet at various angles, the bass is perceived as attenuated and when 2 sound waves meet or collide head on, the bass is perceived as totally absent since the 2 waves cancelled each other out resulting in what is termed a ’Standing Wave’.
As I’ve stated before, the only currently known method of attaining very good bass response throughout an entire room is to deploy what is called a ’Distributed Bass Array System’. The DBA system is a scientifically proven method (developed by 2 doctors of acoustical engineering, Earl Geddes and Floyd O’Toole) that consists of 4 subs strategically positioned in a room that is exceptionally effective in significantly reducing the number of bass modes in any given room.
An additional benefit of the JL f112 sub is that it’s fairly simple to add additional JL subs if you ever wanted to. The existing sub is termed the ’Master’ and an additional JL sub is called a ’Slave’. Only a single cable is required for connecting the slave to the master. Multiple slave subs can be connected connecting them with a single cable in a daisy chain method and the master recognizes all attached subs as a single bass system.
So, you both currently have very good bass response at your listening position and have the option to incrementally improve that bass response by adding properly positioned subs. If you decide to deploy a DBA, you’ll attain state of the art bass response throughout your entire room and likely be able to charge admission for music or ht.
Enjoy,
Tim
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guhlamr,
I doubt anyone would notice a difference between a hi-end and Monoprice xlr cable on a sub. I suggest saving your dough and making your wife happy, or at least less ticked-off.
Tim
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