Whatta Ya Think About Hsu Research Subwoofers?

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).

And it doesn’t have to be 4 subs. I have 4. Having 4 is awesome and a great option, but might not be the best solution for everyone. It’s certainly not an option in my 12’ X 12’ room where I have my Harbeth P3ESR’s set up. A single entry level 12" sub works great in that system.

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.

Nicely dismissive, Tim!  Lol

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.   

audioguy85:"Otherwise, keep the sub where it belongs, on a home theater set up. Maybe it’s just me, I don’t get it. Only an opinion, be nice..."

Hello audioguy85,
     Well, you're right about one thing, you really don't get it. 
     I think snapsc gets it and it's probably because he didn't let old and tired misconceptions and biases against using subs in one's music audio system stand in his way.  None of those things mattered to him or me.
     What matters to us is keeping an open mind about improving our systems and getting closer to the music.
     You state you don't get it and I believe you.  I've come to the conclusion that nobody, with myself and a surprisingly small group of others included, really gets or truly understands how amazingly well multiple subs in a distributed bass array actually perform until they  experience it. 
     I now believe it's simply that there are 2 groups of individuals: those who have experienced a 3-4 sub DBA system and those who have not.  The first group have all bought or created their own custom 3-4 sub DBA system and enjoy near sota bass performance on a daily basis for music, HT or both.  The second group, having never experienced a 3-4 sub DBA system, have no idea what they've been missing and remain blissfully ignorant. 
     So ultimately you're correct, you don't get it and you just don't get to enjoy near sota bass performance on your system and music on a daily basis.  Congratulations, but at least you still have blissful ignorance going for you.  

I was nice, right?
     Tim

Speakers that can produce deep bass often run in to the problem of real world rooms that have peaks and nulls. Multiple subs are a way around this... and once you experience the ambience created by deep bass, even at low volumes, you won’t want to give it up.

I think that if you need to use a sub then you bought the wrong speakers. Using subs defeats the whole idea of stereophonic 2 channel reproduction and is sacrilegious (lol). Buy speakers that produce prodigious amounts of bass if that is your thing. Otherwise, keep the sub where it belongs, on a home theater set up. Maybe it’s just me, I don’t get it. Only an opinion, be nice...

Hello bob540,

     Each of your ML 60XT speakers have rated bass output from their dual 8" woofers of 35 Hz +/- 3 dBs. Humans are capable of hearing bass frequencies down to 20 Hz. Virtually all commercially available recorded music (CDs, LPs and digital music files) have all of the left and right channel bass picked up by the recording mics, that are below about 100 Hz, summed to mono during the recording’s mixing process. This is done because humans generally cannot localize (determine exactly where bass sound tones are coming from) on bass frequencies below about 80 Hz.
     In practical terms, the above means there’s no such thing as true stereo deep bass because we can’t determine where bass frequency sounds below 80 Hz are coming from and, even if we could, virtually all of the recorded music we play on our systems is summed to mono below 100 Hz anyways. So, it makes no difference whether we setup our playback systems for true stereo deep bass or mono deep bass reproduction since we’re going to perceive deep bass as mono either way. It’s also important to know that we get progressively better at determining exactly where sounds are coming from as the sound frequency gets higher, from about 80 Hz all the way to our audible high frequency sound limit of about 20,000 Hz.
     But it gets more complicated than this and all hope is not lost due to our remarkable brains and the fact that that all deep bass fundamental tones have overtones or harmonics that are at frequencies that reach frequencies well above 100 Hz, are recorded in true stereo, are played back through our main L+R main speakers and that we are able to localize (determine exactly where these bass overtones/harmonics are coming from).
Fortunately, our brains are able to associate these bass overtones/harmonics that are at frequencies that reach well above 100 Hz, we are able to localize, that are played through the main stereo speakers, with the deep bass fundamental frequency tones that are below 80 Hz, that we are not able to localize, that are played through the subs and, therefore due to our brains sound processing power, we are effectively able to determine specifically where deep bass tones below 80 Hz are coming from.
     This cerebral association process is very relevant to audio because it allows us to perceive exactly where in the stereo sound stage illusion that deep fundamental bass frequency tones are coming from. For example, the upright bass can be properly perceived as being located at the front left of the sound stage and the deep bass drums can be properly perceived as being located at the center rear of the sound stage. I’m sorry for all the detail but I think this information is essential in understanding how to attain improvements in bass performance quality in our domestic sized rooms and systems.
     As I mentioned at the beginning of this post, your ML 60XT main speakers are rated to have bass extension down to 35 Hz, which means you’re currently not hearing or feeling any of the deep bass content on any of the music you play from 20 Hz to about 35 Hz.
     This is basically the entire bottom 2 octaves of the musical spectrum, that forms the solid foundation of most musical genres and that I’m not even sure you realize has been completely absent from every track you have ever played or will play on your current system.  But I believe your interest in adding a pair of subs is likely based on your sense that a large and critical portion of the audible frequency spectrum has been missing in action from your system and musical enjoyment. So we’re in absolute agreement that your system needs a pair of good quality subs like Trump needs a brain and a soul.
     My opinion that a pair of HSU uls-15 MK2 subs you linked to are a very good choice. They have high quality deep bass extension down to the audible limit of 20 Hz, have the 3 required controls (volume, crossover frequency and continuously variable phase.) and each has the proper line level rca ’Sub In’ input for connection to your P5’s line level rca ’Sub 1’ and ’Sub 2’ outputs, respectively.
     I also think your P5 is an ideal preamp to use when adding a pair of subs to one’s system since it has dual line level rca mono sub outputs with a built-in adjustable low pass cutoff frequency that controls the range of bass frequencies sent to both connected subs. The P5 also has line level rca L+R main speaker outputs with a built-in adjustable high pass cutoff frequency that controls the range of bass frequencies sent to your
A21 amp first and then on to your main speakers. These are both very useful controls that we can discuss how to best utilize and set on future posts.
     Just one more opinion, I think you might want to consider paying the extra $150 per sub for the rosewood finish. You’re going to be seeing these subs in your room on a daily basis for probably at least a few years. I think the fact that you didn’t pay the relatively small extra money to have them better match your ML main speakers may nag at you long after you’ll remember or care about saving a bit of money in the short term. Just something to think about since it’s your money and decision.
     The last thing I want to mention is you’ll need 2 single mono male-to-male line level cords to connect each sub to your P5 preamp. If you use the crawl method to optimally position each sub in your room in relation to your designated listening seat, and begin your search at the right front corner of your room and proceed counter-clockwise around the perimeter of your room as recommended, I strongly suspect you’ll discover that the bass sounds best at your listening seat with both subs positioned along your front short 14’ wall. It could be with one in each corner but my experience makes me think they’re most likely to sound best with both subs along the front wall with one about 1-2’ away from the right front corner and the other 1-2’ away from the left front corner.
     I still suggest you just faithfully follow the crawl method and position them precisely where they sound best to you. But this means it’s best to buy one 8-12’ mono rca cable for Sub#1 and the one for Sub#2 much longer, at least to start with. If I’m correct about sub positioning, you could probably just exchange the extra long cable for another 8-12 footer or just buy another. But if I’m wrong, you’ll probably need it because the optimum position may be along your left long wall with the windows and you’ll need to avoid positioning Sub#2 directly over an hvac vent.

Later,
Tim

@bob540, your room's volume is not that big, and it sounds like floor space is at a premium. While a pair of ULS-15s would provide all the  low end you could want, you might have better placement options with a pair of SVS 12" subs (something like the sb-2000 pro). Although they don't have the rosenut veneer of the ULS, which is really nice if aesthetics are important.

@bob540    That would clearly be the best choice out of the Hsu line for both aesthetic and musical reasons.  Your room does sound a bit tight, so you clearly would have issues with placing larger cabinets.  It's hard to predict where your subs will sound best.  Two is better than one for reasons noted above.  I lugged my subs to all the different placement options I had in my room. (You can see a pic of my room under Virtual Systems). In the end, they worked the best corner loaded.  Every room has its different set of resonant modes and nulls.  You just have to try it and see where things sound best from your listening position to your ears/taste.  The test CD Hsu provides is helpful as well music with deep bass content that you are well familiar.  Would be happy to look at pics of your room if you would like.

Thank you to all who have responded to my question — I’m a beginner at this and trying to learn (I sure don’t mind the study!), and I want to benefit from the experiences and informed opinions of the members here.

It looks like the consensus here is that a pair of subs (if not more) gives better results than a single sub.  Also, that I would be happy with the Hsu’s.  The model I am looking at is this one:

http://www.hsuresearch.com/products/uls-15mk2.html

I prefer the looks of the rosewood (would go with my Martin Logan’s) but for the price difference I could be satisfied with black.  The biggest challenge for me is space.  My listening room is 14x19 and a short ceiling (less than 8’), with my equipment along the shorter wall.  The foot traffic passes right in front of my set-up to the garage and a laundry room, so space is pretty tight.  My Martin Logan’s are ported and said to sound better away from the wall, but this would put them in the path of people walking through.  Adding two subs to the mix — I’d have to figure out how to do that and not have them blocking the path.  I have a large fireplace that takes up most of one wall, large windows taking another (and heating vents below them that I want to keep my equipment away from) and an overśized sectional that dominates the other wall.  So, gotta work within prescribed limits.  I could post a pic of what it looks like, if you could offer suggestions?  

Mr. Contuzzi
You are missing the point.  I am sure your subwoofer is bigger than mine.  But the OP is looking for an affordable sub.  Not yours--whatever it may be.  Why would you even post on this thread?  Oh, guess I already answered that.

contuzzi363 posts02-22-2020 7:09amA HSU is a fine sub until you try a better one.  There are many many subs out there that are far far better for music.  
I’ve owned a ULS15 and a pair of VTF subs and have found several sub woofers since then which completely blow them away.  The funny thing is, when I owned the ULS for instance, I thought it was an amazing sub too.

+1
Almost any optimally setup sub is better than no sub at all. Experiencing a low frequency systems presentation attributes from actual in home comparison can give one another horizon. I can't help but remember a friends astonishment when he heard his old school sub fed an equalized signal for the first time.  

For the money,
Hsu subs are very good. I own a pair of VTF mk2 subs for my office.

I only add the caveat that due to owning a pair Vandy subs, as well.
The integration and bass provided by a Vandy subs (coupled with the high pass filter) offers a much better 'seaming' of the sub and loudspeaker.
@OP,
If you can up your budget, a pair of 2wq subs and fixed crossover would be close to $1.5K.
Bob

     I read that contuzzi and corelli wisely use a pair of subs in their systems.  But I'm just curious if other posters on this thread have experienced the many very significant bass performance quality improvements realized when multiple properly positioned and configured subs are deployed in their rooms.  
     If anyone is still utilizing just a single sub in their room/system, I can assure you that adding a 2nd sub will provide an obvious and highly significant improvement in bass performance quality. 
     Utilizing 3 or more subs will provide near state of the art bass performance quality that I'm fairly certain will stun and amaze you, as first experiencing  the bass performance quality of a 4-sub DBA system in my room and system stunned and amazed me about 4 years ago.  I honestly don't believe it's possible for me to overstate how effective the DBA concept actually works in virtually any room and with any pair of main speakers.
     The only precautions worth mentioning are that you'll need separate controls on each sub for volume, crossover frequency and continuously variable phase if you create your own custom 3-4 sub DBA system using traditional self-amplified subs of your own choice and you'll need to set these controls individually on each sub.  If an Audio Kinesis complete 4-sub Swarm or Debra DBA system is used, however, all 3 of these controls exist on the supplied Dayton SA-1000 class AB 1K watt amp/control unit and only need to be set for all 4 passive  subs this amp powers in mono mode.  Each sub is 12"wx 14.5"dx 28"h, weighs 44lbs, contains a 10" aluminum long-throw woofer and is rated at 4 ohms.
      Another option for those who are handy and so inclined, is to buy a Dayton SA1000 sub amp/control unit for $300-400 from Parts Express and build 3-4 passive subs of your choice as to size, design and driver.
This option also has the benefit of only needing to set the volume, crossover frequency and phase once for all passive subs this amp/control unit powers in mono mode.  All sub wiring connections are made in series/parallel.  Depending on the choices made on the DIY subs, however, the total cost could exceed the $3K price of either of the AK complete 4-sub DBA kits.

Tim

Corelli: I had a ULS15 and then bought a mkII as a mate.  I tried both alone and both were similarly disappointing compared to what I’ve found since then.  In fact, the mkII is still sitting at my friends, who is saving up money to upgrade.

SVS are a good choice too.If you buy two they are discounted.Worth a look anyway!I'm very happy with mine.

If budget is an issue, SVS has some affordable sealed subs. I have one of their older SB-12 NSD subs in my computer room system. 

Of course there are "better" subs.  But the OP has a budget.  I would also take the above comments with a grain of salt.  The older series models do not perform at the same level as current models.  Also, I much prefer a sealed design for music at this price.  

I found HSU to be a step along the path to finding good subs.  I started out with a couple of Klipsch subs, which were complete garbage.  I then had a couple of HSU subs including the VTF-1, a VTF-3 MK3, and a VTF-3 HO.  The VTF-1 was surprisingly good for the price (200 bucks at the time?).  The VTF-3 MK3 was a solid performer.  The VTF-3 HO sucked.  It bottomed out really easily.  I bought it second hand, so maybe it was damaged, but when I contacted HSU and asked about it, they acted like that was "normal".  

I moved on to SVS, Rythmik, and Power Sound Audio and never looked back.  They all seemed to be better built and to have more output and tighter bass than the HSU subs I had.  Maybe a little more expensive, but more value for the dollar. 

That was a couple of generations of HSU subs ago, so maybe they've stepped up their game with their latest offerings. 

My impression of them was that they are the Emotiva of the subwoofer world.  Affordable and sound OK, but for not much more money you can have better build and sound quality.

A HSU is a fine sub until you try a better one.  There are many many subs out there that are far far better for music.  
I’ve owned a ULS15 and a pair of VTF subs and have found several sub woofers since then which completely blow them away.  The funny thing is, when I owned the ULS for instance, I thought it was an amazing sub too. 

Cue the offended HSU owners... 

I also have a pair of ULS-15's in my main system.  I think these sealed subs offer very high quality bottom octave coverage for music.  Some might think that with Tekton DI's you wouldn't need subs--but not me!  I am not about an excess of bass.  Rather, I demand tight, musical bass that plumbs the depths that my main speakers just don't do--especially pulled well out into the room.  I've said before that they complement the DI's beautifully--super high value, nicely finished, tremendous performance.  Buy a pair and be happy.

Hello rocray,

     Yes, 3-4 subs properly positioned and configured in a room qualifies as what's called a distributed bass array (DBA) system that's been scientifically proven to be one of the most effective sub-based bass solutions that can also be utilized in any room and with any pair of main speakers, even those very fast and detailed speakers considered very difficult to integrate subs with such as planar-magnetic and electrostatic type speakers.
     In my experience, a3-4 sub DBA system will perform and sound about twice as good as utilizing a pair of subs. Adding 1-2 subs to a pair of subs and positioning them in a distributed bass array configuration results in a further improvement in bass performance in terms of speed, smoothness, detail, power, impact and dynamics.  It will also extend this near state of the art bass performance  throughout the entire room, not just at a single listening position as is the case with using a pair of subs. 
     I utilize a 4-sub DBA complete kit system, an Audio Kinesis Debra system, with results I find very accurately described in this Absolute Sound review of the Audio Kinesis Swarm 4-sub DBA complete kit system (which is identical in price and performance to the AK Debra system but the relatively small subs are more rectangular than the Swarm's squarer shaped subs.):

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

     My advise is that multiple subs will provide significantly better bass response than a single sub is capable of providing, no matter its size, quality or price.  If your goal is to optimize the bass performance in your system, or prefer near state of the art bass performance throughout your entire room rather than just at your designated listening position, then I recommend using either an AK complete kit 4-sub DBA system or a custom 3-4 sub DBA  system utilizing your choice of subs.
     If you want to learn more about the effectiveness of the DBA concept, 3-4 sub distributed bass arrays and in-room bass response in general, you can google " distributed bass array concept" or "distributed bass array system".

Best wishes,
     Tim

Oops! The models I have,2- STF1’s,1-VTF2 Mk3. My room is 9x13x8.

I own and use 3 HSU subs in my listening room. I purchased all 3 on the used market about 3 years ago. The work flawlessly,and sound great. Other than when we go away on vacation,they stay powered on 24/7. Not so much as a hiccup.

Hello bob540,

     I've never owned a HSU sub but wouldn't hesitate to purchase them based on their very good reviews, reasonable pricing and generous return terms. 
     However, I would advise buying a pair rather than just a single sub.  Based on my experience, a pair of subs will perform and sound about twice as good as a single sub.  Bass is cumulative and having 2 will provide a more accurate, realistic and natural presentation of the bass impact and dynamics recorded on the source content with neither sub operating anywhere near its limit.  
     Having 2 subs running in mono mode, properly positioned in your room and in relation to your listening seat, will also provide the normal multiple subs in a room benefits of the bass being smoother, faster, more detailed and better integrated with the main speakers than a single sub is capable of.  The soundstage normally sounds wider, deeper  as well as more realistic, open and natural.
     Besides choosing a pair of HSU subs that match your physical size and budget requirements, you need to make sure the subs have separate controls on each for volume, cutoff frequency and continuously variable phase, I believe most if not all HSU sub models have these. If your budget is tight, I recommend that utilizing 2 smaller and less expensive subs will perform better than a single larger and more expensive sub in virtually any room and system by a wide margin.
      Useful skills to learn are how to optimally position and configure 2 subs in a room.  I suggest googling the 'crawl method' for positioning and setting the volume and cutoff frequency controls on each sub as low as possible with the bass still sounding good to you (powerful, dynamic, detailed and natural).  Remember, the goal is not to constantly hear and feel the contributions of the bass from the subs but for them only to  supplement the deep bass when the content calls for it.

Best wishes,
     Tim

I owned a pair of Hsu ULS-15s for many years.
Excellent presentation across the entire band and extremely reliable. I left them powered up 24/7 and never had to touch them. 
I owned a pair of SVS 12" SB12S prior the HSU, and the Hsu's offered a lot more output. Granted, its not a fair fight, but the 15s are not of the one note variety. Excellent in a 2.2 music system. 

I'm a sealed sub guy so can only speak to the ULS-15, but their ported units are well regarded among the HT users. Definitely worth looking into. 

HSU subs are the bomb! If I am in the market for a sub, I am buying HSU again. Especially for the money, I don’t think any sub can touch it. 

You will get amazing bass from four of them.

Smart money.

Oops, sorry, not listening to them right now, forgot they are only on the HT loop right now. 

Still, I stand by my comments. :) Hsu are seriously underrated.

Erik beat me to it. They make a great product and are not priced in the stratosphere. I had an original VTF-2 and it was great. Their Variable Tuning Frequency design gives you more flexibility to tune the sub to your room. 
They have as good a return policy as anyone, and Mr. Hsu has been at this a very long time. I would not hesitate to recommend someone give them a try. 

Love them. Have one I'm listening to right now. :)

GORGEOUS, big, powerful. Easy to set up.