Whatta Ya Think About Hsu Research Subwoofers?


I’m in the market to add one or possibly two subwoofers to my stereo set-up.  I would like to spend $1,000 or less per unit, and that puts some of the higher-rated units out of reach.  I came across an ad for Hsu, which I had not heard of before.  I didn’t want a Chinese product and it turns out that Hsu Research is based in California and founded by Dr. Hsu, who has a Ph.D from MIT.  Audio reviewer Steve Gutenberg gave one Hsu product a positive review.  I was wondering if any of you have experience with Hsu and could share your impressions/recommendations with me.

My existing set—up is:  Parasound P5 pre-amp with Parasound A21 amp;  Martin Logan 60XT tower loudspeakers.  Thanks!
bob540
Hello Bob,

     The subwoofer crawl method is just a simple but very effective method to determine the optimum position in the room for each of your subs without using any expensive equipment, just you and your ears required. Here's a  a link to a video explaining how to do it:

https://www.youtube.com/watch?v=AV3oLLMgS-M

     If you'd like to learn more about utilizing dual subs in a room, along with the typically most successful room positions, I suggest you use Google because there's a lot of info on this subject.


Tim
Tim, I saw that you mentioned the “crawl method” for determining best position for subs. Does that involve moving the subs a little at a time and listening to the sound each time?  i.e., being on my knees crawling about with them til I find the sweet spots?

Good advice regarding the RCA cables.  Oddly, I have the subs coming but don’t have the cables ordered yet.  
Hello Bob,

     Okay, it seems like you have a good plan for routing the required  single rca cable from your P5 preamp's Sub Output 2, past both the doors to the line level input on the 2nd of your SVS subs.  The 1st SVS sub, positioned to the left of your equipment rack, will also require a single rca cable run from your preamp's Sub Output 1 to the SVS sub's line level input. 
     As I stated earlier, I have no doubt that you'll be able to attain good quality bass performance at a single listening position in your room utilizing 2 good quality subs like the two SVS subs you bought.
     But it's very important you understand that just plopping down each sub where it's convenient, you have the space or where you prefer them being located, is a highly unlikely path to success. Ideally, the best process is to use the crawl method to determine the exact position in your room for SVS sub#1 at which the bass sounds the best at your designated listening seat.  Then with sub#1 optimally positioned and playing, the crawl method is used again to determine the exact position in your room for SVS sub#2 at which the bass sounds the best at your designated listening seat.  The final step is to optimally set the volume, crossover frequency and phase control settings on each sub.
     By determining that you only have one possible position for SVS sub#1 in your room which is to the left of your equipment rack along your front wall, however, this ideal locating process has already been compromised.  It's possible you still might be able to attain good bass performance at your listening seat but I think this would definitely require you to use the crawl method to optimally position SVS sub#2 in your room.  The exact optimum position in your room to locate sub#2, however, will probably not be on the ledge that is part of your fireplace. 
     I suggest you buy the longest rca cable you can because the optimum exact location for sub#2 could be anywhere along the perimeter walls of your room; further down your fireplace wall, along your rear wall or even your wall opposite the fireplace.  Using the crawl method, it will be fairly obvious when you find the optimum room position, the bass will suddenly improve in its quality and become more solid, smooth, fast, detailed, realistic and natural.  
      In the meantime, it would be useful to reread your preamp manual's sections on about how to connect a pair of subs beginning on page 10 of the attached P5 maunual below:

https://parasound.com/pdfs/P5Manual.pdf  

Tim   
Sure.  I plan to put the subwoofer to the right on a ledge that is part of the fireplace, just to the right of the second door.  I will run the cable for that beneath the first door, where the carpet ends and vinyl flooring begins.  I will tape it down so that it isn’t a tripping hazard. I will run the cable around the corner and then tape it to the inner part of the threshold for the garage door, then up to the short ledge where the sub will sit.  I have to avoid stepping on the cable going through the doors, but that shouldn’t be a problem as the floor surface is uneven at both of those spots anyway.  I could look at covering the cable with some sort of protective strip, like you see at concerts where cables must be run through traffic areas.
Hello Bob,

     I actually wrote and posted my last thread post before I even read  your post about your decision to buy a pair of SVS SB-2000 subs.  I believe you wrote your post before me but somehow it was delayed in being posted because I didn't see just read your post on Saturday night.  I don't want to take back or change anything I stated but, given your room, I am a bit surprised you decided to buy wired subs and not choose the more convenient option of wireless subs. 
     
     However, it sounds like you have some ideas and plans about how to run and conceal the wires you'll need to run from your preamp to a currently unknown exact location for the second SVS SB-2000 sub that needs to be located along one of the 3 remaining walls in your room ( a wall other than the front short wall where your tv, equipment rack and main speakers are currently located, as well as the wall the first SVS SB-2000 sub will be located.). 
     Can you state your plans about how you plan to connect both SVS subs, using line-level rca cables from your preamp or using high-level speaker wire connections to your amp? 
    And about how you plan to run the wires past the the 2 doors in the right front corner of your room?

Thanks, 
  Tim
Hi Tim.  The real advantage of the ML subs over what I chose would be the Bluetooth capability.   Same with Syzygy, but even more so, as the Bluetooth transmitter can communicate with up to 8 subwoofers.  That is capability!  But I made my choice on the basis of capabilities and price, and I look forward to listening to them in my system.
Hello Bob,

     You should know that I've never personally heard many of the subs discussed thus far on your thread, including any from HSU, ML, Syzygy and SVS.  I have, however, personally owned and listened to many brands and models of subs from JL, B&W, M&K, Vandersteen, Klipsch, Polk, Audio Kinesis and REL.  For years I experimented with these subs in various quantities and room positions in an attempt to attain the highest quality bass in my system and room, initially with single subs, then dual subs and ultimately my search ended very successfully just over 5 years ago when I tried the Audio Kinesis Debra 4-sub DBA system in my room.       
     I was pleasantly amazed at the immediate and huge improvement in the impact and quality of the bass in my room produced by this 4-sub DBA concept system as well as how seamlessly it integrated with my Magnepan 2.7QR main speakers that only had a rated deep bass extension of 35 Hz.  I've been using this system ever since with outstanding results on both stereo music and on my home theater 5.1 surround sound system.
     I've read statements from various acoustic experts that 3-sub DBA systems are capable of bass performance nearly as good as 4-sub DBAs if each of the 3 subs are properly positioned and configured.  I don't doubt this is true but I've never personally bothered to verify this in my room. But I've read numerous Audiogon posts from members stating that 3 sub DBAs have worked extremely well for them in their rooms. 
     My general advice, based on my experiences, is that 2 subs perform about twice as well as 1 sub and 4 subs perform about twice as well as 2 subs.  Based on what I've read, I really just assume that 3 subs will perform very well but perhaps not quite as reliably as well as 4 subs.
     However, I'm certain that a pair of subs, properly positioned and configured, are more than capable of providing very good bass performance at a single designated listening seat in virtually any room.  The benefits of adding subs beyond 2 in the room will typically be perceived as the bass having increased power, impact, dynamics and a sense of ease quality along with it being faster, smoother, more detailed and this high quality bass will be perceived throughout the entire room, not just at the designated listening seat.
      By now it's obvious that I tend to sacrifice brevity for the sake of detail on my posts, Sorry.  Finally, you asked:
" If I am considering Bluetooth subs, how about this one from Martin Logan.  12” drivers with Bluetooth capability, and they look similar to other models costing more (which doesn’t mean they sound as good . . Don’t know):

https://www.amazon.com/MartinLogan-Dynamo-12-inch-Wireless-Subwoofer/dp/B002O3W2SO/ref=pd_di_sccai_1... "

     Since discovering and installing the A K 4-sub DBA system, I'm no longer reading about, researching and listening to the numerous subs available.  I still haven't listen to the Martin Logan 1000W sub but I did research it a bit and read a few very positive reviews.  This sub has a rated bass extension down to 22 Hz, has the necessary separate controls for volume, cutoff frequency and continuously variable phase, has the correct L+R rca inputs to connect to your preamp, has an updated wireless system, costs less than the Syzygy subs and looks cooler.
     What's not like?  I think a pair of these to start seem like an excellent choice for your room, system and circumstances.

Tim
I made my purchase — a pair of SVS SB 2000’s.  They are the discontinued model that was replaced by the 2000 Pro, and I could still get them for $649 each with free shipping.  The only difference between what I got and the Pro is that the latter has 50 watts more amp power and the ability to control the Pro with your phone or tablet.  I don’t need to control the subs remotely — I can get up to adjust them if needed.  They have 12” drivers that can be positioned to fire down or out.  They don’t have Bluetooth but I will secure the one cable out of the way so it is not a tripping hazard.  The Martin Logan’s I referred to in last entry have Bluetooth but the comments I saw on-line indicated that the SVS sound better.  I still don’t have the ideal listening space, but I might just pull my Martin Logan towers away from the wall to see how much better they can sound.  A little experiment.  Thanks again to everyone who responded and provided good suggestions.
scm:  Nothing special about 540.  It was just a number I tagged onto the end of my name to differentiate me from all the other Bob’s on a discussion forum.  Glad you are liking your Hsu’s — they look like nice subwoofers.

If I am considering Bluetooth subs, how about this one from Martin Logan.  12” drivers with Bluetooth capability, and they look similar to other models costing more (which doesn’t mean they sound as good . . Don’t know):

https://www.amazon.com/MartinLogan-Dynamo-12-inch-Wireless-Subwoofer/dp/B002O3W2SO/ref=pd_di_sccai_1...
Hello Bob,

     This is a direct quote from you on your post from 2/24/20: " There is space to the left, as I can move the tower that holds my CDs and the record albums. I wish I had Bluetooth capability for the subwoofers, as I could place one further to the right out of the line of foot traffic, and then I have space for one on the left. I could cover the cable with a small throw rug I suppose.
     Bob, the Syzygy subs are exactly what you wished for; Bluetooth capable subs that are wireless and let you use an IOS or Android smart phone as a remote. You can place one to the left of your rack and the other anywhere in your room without running any wires. No throw rug to cover the cables is needed since there are no wires or cables connecting the subs except a power cord for each to the nearest a/c outlet..
     They’re made in the U.S.and there are 2 versions which have either 10 or 12" drivers:
The Syzygy SLF850 utilize 10" drivers, have a rated bass extension down to 24 Hz and are priced at $799 +$60 shipping=$860 each on Amazon.
The Syxygy SLF870 utilize 12" drivers, have a rated deep bass extension down to 20 Hz and are priced at $999 +$50 shipping=$1,050 each on Amazon.
Here’s a link to both on Amazon:
https://www.amazon.com/Syzygy-Acoustics-SLF-870-Subwoofer/dp/B01KBTWAL6?th=1

I     f you’re serious about your wish for Bluetooth capable subs and attaining very good bass performance in your system, I suggest you begin with a pair of 12" SLF870 subs, which will provide very good bass at your designated listening seat down to 20 Hz.
     Then in the future when you’re ready, you could add a third 10" SLF850 sub, which will provide even higher quality bass quality not only at your designated listening seat down to 20 Hz but throughout your entire room. Even though only 2 of the 3 subs are reproducing deep bass down to 20 Hz and 1 sub just to 24 Hz, the overall bass will sound like it extends to 20 Hz in the room.
     This results because adding the third sub creates the necessary minimal number of subs in any given room to qualify as a distributed bass array (DBA) system. The 3-4 sub DBA system concept has been scientifically proven to modify the bass sound wave behavior in any given room in a specific manner that creates a bass sound wave environment that our brains process and perceive as the overall bass being fast, smooth, extended, powerful, dynamic, detailed, natural and seamlessly integrated with the main speakers.
     I realize this all likely sounds a bit confusing to you. In general, the 2 sub solution works well at a single designated listening position while the 3-4 sub DBA concept solution works significantly better, as in about twice as well, throughout the entire room and like a charm. An Audio Kinesis Debra 4-sub DBA system has been providing near state of the art bass performance, for both music and HT in my room and system, for over 5 years now and I see no reason it wouldn’t do the same for music in your room and system with a custom 3-sub DBA system provided the subs are properly positioned and configured (configured meaning the volume, crossover frequency and phase controls are all properly set on each sub, which I can assist you with).
     However, I think you need to decide whether you want to utilize and run line level cables to traditional self-amplified subs like the HSU or utilize the newer technology Bluetooth wireless subs like the Syzygy.
     There’s also a third option available, which is to buy a Dayton SA1000 1K watt class AB sub amp/control unit for $300-400 from Parts Express (which the AK Swarm and Debra 4-sub DBA kit systems utilize) and use 2-4 less expensive good quality new or used passive subs connected via speaker wires. You’d also be able to progress with this amp from using 2 passive subs in your room to using 3 or even 4 subs. The main downside is running and concealing the speaker wires to them.
    All 3 solutions will produce equally very good results with a pair of subs and will produce near state of the art bass results with 3-4 subs. I’m willing to assist you with any option you choose.
     It seems like the wireless Syzygy subs may be a bit more expensive, mainly due to the shipping charges, but they’re also a lot more convenient, especially in your room. Are you willing and able to run speaker wire or line level rca cables to other areas of your room to save some dough? Or, do you prefer convenience? Let me know.

Tim
bob540  I bought 2 HSU ULS 15`s a couple weeks ago, still breaking in and they sound very VERY nice.
Curious...is '540' a BBC reference ? :)
Tim, I am usually the sort of person who can window shop, see nice things and pass them by without stressing over not buying them.  But occasionally I get on a bent when I see something and think, “Someone else has this and is enjoying it, while I am stuck with . . . this.”  There is a audiophile-type stereo and home theater store not far from me, and I have thought, “Why don’t you just go and hear this equipment for yourself instead of reading about it or asking for others’ opinions?”  But then I fear that I will go there and hear or see things that are so excellent, but beyond my budget to afford, and then I return home and am thereafter dissatisfied with what I have.  I don’t feel that way when I see a fancy sports card or a palatial home, but I could see myself longing for an exquisite sound system. I could see myself obtaining some new music and enjoying it on my system, but then thinking, “I wonder what I am not hearing that would be revealed by that expensive gear I sampled the other day?” It can be a feeling of pleasure-denied.  
Hello Bob,

     Forgot to mention, driving yourself crazy with this audio stuff is a choice and one I don't recommend.  I consider this audio and music hobby a journey and try to enjoy it along the way.

Keep it fun,
    Tim
Thank you guys again for your suggestions — I am going to look again at Syzygy and at GR Research/Rythmik.  Funny how I didn’t agonize before buying the Martin Logan’s, but now I wonder if I should have bought KEF LS50’s and paired them with subwoofers — would have saved space and all I read is raves about the LS50’s sound.  You could seriously drive yourself crazy with this stuff, huh? 🤪

Bob, before pulling the trigger, look into the GR Research/Rythmik F12G Sub. Optimized for music, it employs the GR Research 12" low-mass paper-cone woofer and Rythmik Servo-Feedback system. VERY high quality music reproduction.

If you can build an enclosure, the sub is also available as DIY kit. If you can’t, GR Research has a couple of woodworkers who will make it for you, in any style you want.

Hello Bob,

     Absolutely nothing wrong with taking your time and getting the right subs for you.  Kind of like measuring twice and cutting once.
     I'm a bit surprised you weren't more interested in the Syzygy wireless subs that are about the same price for a pair and they seem ideal for your situation.  I'm just wondering why you seem to not want to give these a try?  Here's the review again:
https://www.tonepublications.com/review/syzygy-slf-850-subwoofer/


Tim
I know what passive loudspeakers are, but I wasn’t sure if the Parasound could power both the ML towers and subwoofers.  From reading responses, I now know the answer is No, I would need a separate amp to power passive subs. I’m thinking I will go with new powered Hsu subwoofers, the ULS 15’s, which I can get in gloss piano black for $779 + $80 shipping each.  So $1718 for two (plus tax that will likely be added).  This is comparable to the SVS SP2000 Pro subs in gloss piano black that cost $1699.00 for the pair with shipping free.  The SVS have 12” drivers while the Hsu have 15” drivers, which sounds like more bang for the buck with Hsu.  The Hsu subs that wspohn recommended are somewhat more expensive and are ported designs, which are said to be better for home theater (not my interest) but less desirable for music (bingo!). Just thinking out loud here and I am always open to other opinions.  I thank bdp24 for his ideas as well.  I try not to agonize over every decision, but also try to avoid buyer’s regret.
@noble100, So Bob thinks he can run his speakers and a pair of passive subs off the same amp at the same time?! You’re right, I wasn’t aware he was already using the Parasound on his loudspeakers. I was assuming he knew what a passive sub is ;-) .
bdp24:" A Parasound amp will be fine with them, and as I said the subs came with a passive x/o, so no extra electronics are required. The two woofers can be replaced, or even just re-coned, which I was thinking of doing. I don't know what the price to have that done would be."

Hello bdp24,

     It seems like you're not aware that Bob is using his stereo Parasound A21 amp to power his ML 60XT main speakers.  He can't use this same amp to drive a pair of passive subs, he'd need another separate amp to power a pair of passive subs.  Or, he could use a pair of traditional self-amplified subs.

Tim  
Yep Bob, the 10" woofer is down-firing, the cylindrical enclosure sitting on tall spikes which raise it off the floor. A Parasound amp will be fine with them, and as I said the subs came with a passive x/o, so no extra electronics are required. The two woofers can be replaced, or even just re-coned, which I was thinking of doing. I don't know what the price to have that done would be. 
IMHO the best subs they make are the  VTF-15H MK2.

You really need two, located properly in the room, but they mate better than any other model I was able to audition.
I see they are cylinders.  So all the music is from down-firing speaker rather than from the sides?  Or does sound emanate from the sides and bottom.  I suppose I would need to get a separate amplifier to power them . . . or could my Parasound amp power them?   
bdp24,
I’m not familiar with those subs.  I looked them up and they appear to be from early 1990’s?  I have thus far only looked at powered subs — what are the difference issues involved in using powered vs. passive subwoofers?  

Also, one old forum I visited had a commenter (might have been Dr. Hsu himself!) who said the cost of replacing the subwoofers in old units might be close to the cost of new subwoofers. I would need more info. before deciding if I am interested in your HRSW 10’s.
@bob540, I have a pair of the original passive (no plate amp, but a passive x/o proving low-pass filtering is included) HSU sub, the HRSW10 (Rosewood veneer). They’ve been in storage for years, and I just pulled them out of their cartons. The foam surround on the 10" woofer in each sub has disintegrated (damn California air pollution ;-), but all else is fine. HSU has replacement woofers, so if you want the HRSW10’s cheap, let me know and I’ll list them.
HSU  does charge shipping so do not forget to factor that in when comparing The SVS Gloss Finish Adder
HSU Makes a well regarded Sub[I had a STF-1.great bang for the buck!]

Wolf_garcia!  Of course you’re correct.  How could I be so blind to the perils of “mixing” in this woke age?   I’m blessed that you spoke up while there is still time to avert catastrophe!  I am in your debt Sir!  😝
I'm not sure brand mixing is a good idea as you have to know that when you're out of the room the things are going to argue with each other...nobody wants that. 
Hello Bob,

    Sorry I took so long in responding, Thurs-Friday were spent dealing with a water leakage in my main floor half bathroom. Everything's now not leaking and under control but I had to get my homeowner's insurer involved to repair the damage.
   Unfortunately for you, I think slaw has a good point: " If you get a sub/s, you have no good choices for optimal set-up." I like fireplaces and large windows in a home, but they can sure make things difficult for optimally positioning everything for good audio/video systems.
    But I still think 2 subs will perform and sound much better than one, we just need to figure out how best to incorporate and optimally position them in your room. What do we do when the going gets rough? No, we don't give up and quit. We keep searching for solutions, out of the box if necessary.
     Awhile back on this thread, bigwave1 suggested Syzygy subs that are reasonably priced, can operate wirelessly and have received several good reviews. Here's one of the review examples I found and read:

https://www.tonepublications.com/review/syzygy-slf-850-subwoofer/

     If you have a smart Apple or Android cell phone, this could be a very good solution for you, no cables to run plus you can use your phone as a remote and for taking advantage of their room correction capacity at your listening seat after optimally positioning both in your room utilizing the crawl method.  
     If you agree that a pair of the $800 Syzygy SFL-850 subs are a good solution for your room, I suggest you still start at the right front corner of your room, just to the left of the door to your laundry room and garage, and proceed in a counter-clockwise direction when using the crawl method to optimally position sub#1. From my experience, I expect this optimum position to be along your short front wall where your equipment rack is located, but I can't be certain, so your goal is just to position sub#1 where the bass sounds best to you (powerful, dynamic, detailed and natural) with the volume initially set at about 50% volume, the crossover frequency set at 40 Hz and the phase set at "0" (in-phase).
     For sub#2 positioning, just repeat the same procedure continuing around the room from where you positioned sub#1. I have no expectation where sub#2 will sound best in your room, so I'd just recommend taking your time, listen closely and trust your ears.
     I should let you know that I've never heard any Syzygy subs but from what I've read, I think they seem like a good option for you to try. If you're interested, I suggest you contact Syzygy and see if they offer a free in-home trial period for a pair to audition them. I really like these types of offers since they take almost all the risk out of buying them. Please let me know your thoughts.

Tim      
@slaw,
You are absolutely correct — my space, side to side, is the limiting factor.  But this room is what I have to work with.  I mentioned above that my living room is larger and it would be easier to arrange my equipment there.  But, that room is more visible to anyone coming to my door and I don’t want just anyone to see what I have, for security reasons (plus, while I am currently single, we all know how women react to having a bunch of electronics and speakers in the main visiting space — not well).  My current listening room is more private and gives me the option of a fire in the fireplace while I enjoy music, and I like that a lot.  

The wooden table is one I built when I was 17, almost 50 years ago. That was back when hardwoods were not as expensive as they are now.  It is solid oak, mostly 1.25 inches thick, and I think cost me less than $100 back in 1972.  With all the nicks and blemishes that accumulated over the years, I still love and enjoy it.  You might notice that I added a couple more levels above the table itself, making boxes and a plank that bridges the two boxes in the center.  Yes, it looks cluttered, but it allows me to have all the equipment I might use (and some I seldom do) together and easy to use (except when plugging and unplugging equipment, which can be a hassle).  It all fits under the TV and I don’t think the height creates the problem with placing the subwoofers so much as lacking space on each side does (though I can see that if I had a narrower table, there would be more side space . . that is true. But I don’t plan on replacing my old oak table).  

I have room on the one side (away from the doors) where I can place one subwoofer.  I mostly need to figure out where to put the subwoofer on the right (and, ideally, I would bring the towers out from the wall 2-3 feet — but not sure how I could do that without blocking access to the doors).  It’s a dilemma.
It may be a complete system rearrange is in order. Set up along your long wall.
@bob540,

The main issue has been overlooked. You’re room. I took a look at your system page. I’d try experimenting with room treatments. The big (tallish) center cabinet is nice but not optimal. Too much stuff crammed into that entire space. Then there is the big screen in the center wall. If you get a sub/s, you have no good choices for optimal set-up.
I have been checking out some of the other recommended subs, and SVS and Hsu seem to offer the most bang for the buck (being a bang-for-buck guy myself).  The 12” SVS do have a discount for buying two, but the wood grain ones just do not appeal to me, and the gloss piano black cabinets costs $100 more each.  I can get the Hsu with 15” drivers for a good price — I just need to decide if it’s worth paying $300 more for the pair with rosewood finish to match my towers.  Thanks to everyone that responded to my question.
Post removed 
Hello big_greg,

I definitely agree with you that it’s sometimes hard to pick up on rhetoric in posts since it just happened to me. I’m usually fairly good at picking up on satire, sarcasm and jokes but admit I may need some work on my rhetoric detection skills.
I think we resolved this little misunderstanding between us reasonably and amicably and really don’t think either one of us consider this a big deal or worth further attention. Thank you.
I noticed you wisely avoided answering my questions about our shared hobby of skinning cats. I was fairly sure you’d understand I was just having a bit of fun and have never skinned a live cat, at least as far as you know.
But thanks for elaborating on the very good 2-sub system your fellow music club member has.as well as your own systems. I really don’t consider myself someone who believes that what I use and like is what others should use and like. But I do realize I do get very enthusiastic about things that work very well in my system, such as the 4-sub DBA system, and I probably run the risk of being perceived that way on some of my posts.
I feel like I’m walking a really fine line with the 3-4 sub DBA system concept because it not only works so well for me even without any room treatments, EQ or DSP, it's also claimed to work well in virtually any room and with any pair of main speakers. This seems like the perfect exception to this axiom, a situation in which something that I use and like really is what others will likely use and like. It’s especially difficult not to get enthusiastic about a bass solution that apparently will work for everyone, regardless of their room and main speakers. Heck, not spreading the word seems to be the bigger crime with the 3-4 sub DBA concept.
As you and I know through personal experience, however, excellent bass performance can also be attained in a system and room by using as few as 1 or 2 subs. I think my best solution, when giving advice on this subject on future thread posts, is just to be honest and relate what I stated above on this post.
Thanks for spurring me to more fully explore and evolve my thinking on the subject of sub usage and effectiveness.

Tim
I currently own a pair of uls 15 mk2 paired to goldenear 5 channel system...the subs have fantastic sound quality. Tight and Digs deep for a sealed sub. For music, It can reach the lower midbass to give that kick drum some power too if wanted. You can tune the sub to your taste with the built in eq.  I'm a constant tweeker, but that's the one part of the system I dont feel the need to upgrade.
Hi Tim. The layout of my room is a bit different than you are thinking.  The other short wall is the one with the windows — my sectional is beneath those windows and then around the corner and takes up the wall that is to the left of my stereo (when facing the stereo.  The other long wall, to the right of the stereo (where you see the two doors) is taken up by the fireplace.  So, the only walls I could mount the TV on are where it is or on the long wall where the sectional is — but that latter placement would have my seating backed up to the fireplace.  I put my TV on the only wall that made sense to me, and then I put my stereo equipment where the TV is (and can play TV sound through the stereo equipment.  

While trying to decide how many subs I will get, I will also look into some of the other sub brands others mentioned here . . JL Audio, Rythmik, Rel, Audio Kenisis?   Never hurts to explore options.  
Tim,

I'm a fairly good writer, but understand that sometimes things like sarcasm, jokes, and also rhetoric aren't always easy to pick up on in a medium like this forum.  

The system I mentioned with two subwoofers belongs to a member of our local music club.  I don't recall all of the equipment in his system, or the exact models of his subs, but he had Harbeth Super HL5 Plus speakers (which I purchased for my system after hearing his) and one JL Audio and one Rel sub. 

I'm not sure I have the vocabulary to describe it, but the bass in his system was immediate, articulate, and powerful when bass notes were present, but not overwhelming.  He had a lot of room treatment (bass traps, diffusers, absorption panels, maybe more) and if I recall, his subs were placed in opposite corners of the room.  He mentioned that he had endlessly tweaked his system to achieve the bass performance we heard. 

There were about six or seven of us there and we all took turns sitting in different seats during our listening.  There was of course a "sweet spot" for the best imaging from the speakers, but the bass had no noticeable peaks or nulls in any of the spots where I sat.  It was a relatively small room (maybe 16 X 20 feet?), but it opened into another room on one side.  To my ears, it was one of the best, maybe even the best system that I've heard.  The clarity of the speakers, the soundstage, the imaging, the integration between the subs and the speakers were all sublime.  That's not to say it might not have even been better with another sub or two, but it was a really involving and dynamic listening experience with no apparent flaws that jumped out at me.

My room is bigger and has a few nooks and crannies and opens into my kitchen/dining room.  I have four subs - two Rythmik F25 subs and two SVS SB13 Ultra subs in my system.  It sounds great, and I don't notice any peaks or null spots and when I listen from my kitchen, there's no "boominess" or "one note bass", but it's not as dynamic as his system was.  My guess is that has more to do with the quality/power of his subs and the sound treatment in his listening space.  I've been adding room treatments and continue to experiment with placement of both the speakers and subs, sub settings, and other variables. 

I enjoy my system, but that system set a benchmark for me of what's possible.  That includes comparisons to a $100K system in a dealer showroom, and a number of other systems, both in treated showrooms at dealers and other friends who have high-end systems.  I appreciate and enjoy my system and have put it together on a relatively modest budget.  Employing four subs definitely took it to another level, using equipment I already had, but had only used for home theater in the past.


bob540:
" I just posted a grainy photo in my profile showing the space I am working with.  Sorry it is so dark and fuzzy.  The doors to the right are to my garage and laundry room, so cannot block those.  The table that holds my electronics is centered under the TV — Martin Logan towers are to each side of that, but hard to make out.  There is space to the left, as I can move the tower that holds my CDs and the record albums.  I wish I had Bluetooth capability for the subwoofers, as I could place one further to the right out of the line of foot traffic, and then I have space for one on the left.  I could cover the cable with a small throw rug I suppose."

Hello Bob,

     Sorry, I got sidetracked having a bit of fun.
     I looked at the picture of your room and system.  It's clear enough that I understand your issues with space and traffic patterns.  I can't see the rest of the room, but I believe you mentioned earlier that there's a large sectional couch along the opposite 14' short wall in your 14'x19'x8' room.  Please correct me if I'm incorrect.
     The first solution that comes to my mind is to switch ends for your tv/equipment and your couch.  The back of your couch would be positioned about 3' away from the door to your laundry room/garage door to allow for traffic.  Your tv and equipment would be positioned along the 14' short wall where your couch was.  This format would allow for your main speakers to be moved out a bit from the wall with the pair of subs along this wall behind them.
     I understand there may be obstacles with this solution so I'll wait for your response before offering another possible solution.

Tim
big_greg:" Tim, they were rhetorical questions. As I mentioned, I use 4 subs in my main system. My point was that there are a few people that make pronouncements that may be "true" for them, but they may not be truisms for everyone - "you have to have four subs", "subs are for home theater", etc. What's "best" for one system, one's listening tastes, and their room may not be for someone else."

Hello big_greg,

     Okay, but I just reread your prior post and you sure did a poor job of making it clear your questions were rhetorical and what your point was. Odd, because you were able to clearly make your point in one sentence,  "  My point was that there are a few people that make pronouncements that may be "true" for them, but they may not be truisms for everyone", in your last post quoted above but failed to clearly do so in your entire prior post.
     Good, that clears up the issue of your point from your prior post that wasn't initially clear to me and I agree with your recently understood point.  Thank you.  
     But I'm hoping you could clear up another section of your prior post that I didn't fully understand or had questions about.  You stated:
" The best subwoofer integration I’ve heard to date was done with two subs. Compared to that system, I feel like my 4 subwoofer system is more of a band-aid than a best of class solution. Not that mine sounds bad, it’s very good, but there’s always more than one way to skin a cat."

     I have 2 questions/comments:

1.  Can you elaborate on the this best subwoofer integration you've heard to date that only consisted of 2 subs?  It's not that I don't believe you, it's more a matter of curiosity.

2,  I generally agree with you that there's always more than one way to skin a cat.  Apparently just like you. I'm also very interested and familiar with the various methods available for this hobby.  For example, I typically utilize very different methods depending on whether the cat is dead or alive.  Is this what you were referring to? Can you elaborate? 

Thanks,
  Tim
Tim, they were rhetorical questions.  As I mentioned, I use 4 subs in my main system.  My point was that there are a few people that make pronouncements that may be "true" for them, but they may not be truisms for everyone - "you have to have four subs", "subs are for home theater", etc.  What's "best" for one system, one's listening tastes, and their room may not be for someone else.
big_greg: " If "prodigious amounts of bass is your thing", what difference does it make how you get it, whether it’s speakers or complementing speakers with a subwoofer (or multiple subs)? Even if you just want a "realistic" amount of bass, again, why does it matter how you achieve that? A purpose driven device (the subwoofer) just might be better than one that’s trying to be a jack of all trades (the speaker)."

Hello big_greg,

     The main reason I utilize a 4-sub DBA system in my room is not to have prodigious amounts of bass but to attain the highest quality bass that is sufficiently smooth, fast and detailed to blend in seamlessly with my smooth, fast and detailed Magnepan 3.7i main speakers.
     My pair of 3.7i are 6’x2’x2" dipole 3-way panel speakers produce very high quality smooth, fast and detailed almost full range frequency performance all by themselves in my 23’x16’x8’ room. However, they only have a rated bass extension down to 35 Hz which most people, including myself, would accurately describe as deep bass limited.
     I believe the bass the 3.7is do produce is sufficiently smooth, fast, detailed and, of course, seamlessly integrated with the midrange and treble planar-magnetic drivers that many would not discern a need for external dynamic subs that are notoriously difficult to integrate with planar-magnetic and electrostatic main speakers.
     But I added the Audio Kinesis Debra 4-sub distributed bass array (DBA) system, which is almost identical to the AK Swarm DBA system reviewed on the link attached below, to extend the bass range of the 3.7is down to the audible limit of 20 Hz and improve the deep bass impact, dynamics and realism of music in my room. The AK Debra 4-sub DBA system very successfully achieved this for me while also integrating seamlessly with my main speakers.

https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     You asked: " Even if you just want a "realistic" amount of bass, again, why does it matter how you achieve that? A purpose driven device (the subwoofer) just might be better than one that’s trying to be a jack of all trades (the speaker)."

     You answered your own question. Typical tower or panel speakers are trying to be jack of all trades. Subs and sub systems, however, are purpose built devices that have the dual benefits of being capable of reproducing bass down to its audible limit of 20 Hz and, more importantly, being capable of being independently positioned in the room to avoid the pitfalls of bass peaks, dips and nulls at the designated listening position in your room.
     Tower and panel speakers are typically positioned in a room and in relation to the designated listening seat to achieve the optimum midrange and treble performance along with maxinizing the imaging and the 3D sound stage illusion effect made possible by 2 channel stereo recordings and the playback through 2 precisely placed stereo speakers.
     This main speakers positioning is very important and enjoyable when done properly but the biggest loser in this normal process is bass performance at the listening seat. The precise positioning of the bass drivers (woofers) in the room and in relation to the listening seat is also very important for good bass performance. But they’ve been totally ignored during the normal process of optimizing the position of the main speakers for midrange, treble and imaging performance at the listening seat.
     Proper positioning of the woofers in the room and in relation to the listening seat has been totally neglected and their positions are usually relegated to positions directly below, and physically attached to in the same cabinet, the midrange and treble drivers. It is highly unlikely that the optimum position of the bass drivers in a room and in relation to the listening seat will be directly below the optimum position of the midrange and treble drivers in a room and in relation to the listening seat.
     What could possibly be the solution to this dilemma since the drivers are all permanently attached to each other in the same cabinet or panel and lack the capacity to be independently positioned for optimum performance?
You guessed it, the most basic solution is adding a single good quality sub that can be independently positioned in the room to supplement the bass already arriving at the listening seat from the main speakers and thereby optimize bass performance at the listening seat.
     Progressive improvements in bass performance quality at the listening seat will be achieved by adding good quality, properly positioned subs to the room. The very obvious and progressive bass quality improvements resulting from adding more properly positioned subs to a room are increases in bass smoothness, speed, detail, impact, dynamics, sense of ease, sound stage openness, size and naturalness along with a seamless quality to the integration to the main speakers.
     There are more details I’d like to describe about why it matters where bass performance quantity and quality improvements come from along with the benefits of multiple subs but I’ll stop here for the sake of brevity.

Tim
I use two of the SVS SB-12 NSD subwoofers mentioned above in my main system. They are a discontinued model and can still be had for $400 each. Never a glitch.

https://www.amazon.com/SVS-SB12-NSD-400-watt-Controlled-Subwoofer/dp/B009F8Y7SO
You can give Syzygy a look, wireless, great support, almost bullet proof, auto e.q. and won’t break the bank. Good recent reviews.  
You can give Syzygy a look, wireless, great support, almost bullet proof, auto e.q. and won’t break the bank. Good recent reviews.  
OP, I’ve got the smaller Motion 40s and a HSU ULS 15 MK2 in a room not too different from yours.  It’s a great subwoofer for the price.  Volume knob is less than half way. Crossover I have tried at 60 and it is great.  I bought my sub in black.
I use a pair of HSU's with my Maggie's.  I recently added two more subs, generic 8" in the back corners of my room. So .7" fed by a Parasound A-21.

The HSU subs I run with both ports sealed and crossed over about 90. The back subs have cleaned the bass up spectacularly. Best I have ever had.