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
It may be a complete system rearrange is in order. Set up along your long wall.
@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.
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      
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. 
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!  😝
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!]

@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.
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.
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?   
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.
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. 
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  
@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 ;-) .
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.
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

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.

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? 🤪
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
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.  
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 ? :)
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
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...
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.
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
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,

     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
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,

     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   
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,

     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