Hsu Research Subwoofers

[Gerry S]

I know this topic will "raise eyebrows" because this is a "Classic New England Loudspeakers" forum. Some may feel Dr Hsu doesn't really "belong" here. But I disagree.

I first met Dr Hsu at the Boston Audio Society when he was earning his Doctorates @ MIT. It was in BOSTON where he developed his first prototype subwoofers (HUGE 6' tall enclosures) in his dorm. Capable of producing pure 16 hz fundamentals @ relatively high undistorted SPL, I was impressed. I myself am not a "ultra-deep bass fan". When I heard them demonstrated, it made me "queasy" because 16 hz fundamentals upset my equilibrium for some reason.

But I knew other BAS members who loved organ music. So, I encouraged him to demonstrate his "prototypes" at a BAS meeting. Members were so impressed they requested Dr Hsu build them "in quantity" for sale to BAS members. He personally hand-made the first half-dozen or so (can't rember the exact quantities) in his MIT dorm and the rest "is history".

Dr Hsu has just hooked up his "mid-level" VTF Mark 4 along with a Pioneer VSX-821-K multi-channel reciever into my system. Both items sat there boxed for several months because I was too lazy to hook it up. They are used with my BA HD9's (my "submission" in the BAS "shoot-out" posted by Steve F elsewhere... "AR 4x competive with today's best".

I don't know whether the Hsu configuration is "sealed" or "ported", or what the "specs" are (and don't care). I DO know the following: it contains a 12" driver driven with it's built in BASH amp. The Pioneer reciever has a built-in electronic x-o set to 80 hz (the built-in x-o in the Hsu sub is "bypassed"). Playing just music CD's in stereo only, I'm truly AWED by what it can do. Truly viceral with just about everything I've played on it so far!

Only within the last two days have I played back DVD's in 5.1 using the Pioneer reciever (actually 4.1 because I'm not using a center channel; just the HD9's providing the "phantom center" when sitting in the "sweet spot"). The "surrounds" are modest BA HD7 "bookshelfs" I voiced but laying around unused; put these on stands @ ear level. Again, bass was ASTOUNDING on action blockbusters containing "LFE" material. Whether in "plain stereo" or 5.1(4.1 in my case), total system SPL cababilities far exceed what I can listening to comfortably (or getting a complaint from my neighbors or condo association) !!!

I know there are some here who feel subwoofers in general is best for "home theater" applications; "problematic" for stereo playback applications. I have definitely found the Hsu subs NOT to be "problematic" for "stereo only" applications; quite the opposite. What's eating me away NOW is the the fact that I've know about Dr Hsu and his products since conception. Several decades later am I JUST discovering just what I've been missing all those years.

So Dr Hsu's products may not be "vintage classics" of the AR3 era. But they definately are "New England" in origin. What do OTHERS feel about Hsu Subs (or subwoofers in general) in "stereo only" applications ?

[ligs]

I always liked deep bass that is why I had AR3a, 11 and 9. But after I bought a pair of the the original Hsu Research HRSW10s I sold the larger AR speakers. Used as a pair, the 10-inch HRSW 10s are capable of 109 db down to 20 Hz in room. Producing deep bass without muddling midbass(where male voice can sound thickened) with one driver is almost impossible. Therefore adding a dedicated sub to a good fullrange speaker is the way to go for me. Actually I have three different subwoofers to go along with my three stereo speaker systems. In bedroom, a pair of 6.1-inch Infinity CMMD(Ceramic Metal Matrix Diaphragm) speakers with a pair NHT 1259 subs.

In family room, a pair of Infinity 5-inch MTM CMMD speakers with a pair 12-inch Hsu TN 1220s. In TV room, another pair of 6.1-inch Infinity CMMD speakers with a pair 10-inch Hsu HRSW10s.

BTW, I acquired a pair of AR3's this year. I have to admit the impact and solidity of bass drum from these AR are still awesome!

[Gerry S]

I always liked deep bass that is why I had AR3a, 11 and 9. But after I bought a pair of the the original Hsu Research HRSW10s I sold the larger AR speakers. Used as a pair, the 10-inch HRSW 10s are capable of 109 db down to 20 Hz in room. Producing deep bass without muddling midbass(where male voice can sound thickened) with one driver is almost impossible. Therefore adding a dedicated sub to a good fullrange speaker is the way to go for me. Actually I have three different subwoofers to go along with my three stereo speaker systems. In bedroom, a pair of 6.1-inch Infinity CMMD(Ceramic Metal Matrix Diaphragm) speakers with a pair NHT 1259 subs.

In family room, a pair of Infinity 5-inch MTM CMMD speakers with a pair 12-inch Hsu TN 1220s. In TV room, another pair of 6.1-inch Infinity CMMD speakers with a pair 10-inch Hsu HRSW10s.

BTW, I acquired a pair of AR3's this year. I have to admit the impact and solidity of bass drum from these AR are still awesome!

I too like bass (who doesn't) but also don't like vocals "muddied". I also used to have a dedicated system for each room but have since down-sized to one system in one room only. The challenge in getting ONE system to perform competantly for muti-media applictions seems to have been achieved with the Hsu Sub. All the bass i could want, no muddiness, 5.1 capabable, and no need to constantly tweak the system when switching from multi-channel DVD to stereo only playback of CD's.

I'm sure I can make my system sound "better" because the system was wired hastily so I could be "entertained" while recuperating from bunion surgery. Thus the haphazard speaker locations currently employed (with no center channel) as I watch/listen sitting on my bed (which had to be temporarily re-located to the living room). If my current set -up had to "permanent", i could certainly live with it.

[Gerry S]

What I've learned about the Hsu Sub as currently configured (I asked him directly). It is currently used with both ports opened (tuned to 25 hz). When plugging one port, the system is tuned to 18 hz with "EQ 1" (haven't tried it yet). With BOTH ports plugged (a "sealed" system) substantial loss of bass occurs; not meant to be used this way. Yet, there are some customers who INSIST on sealing both ports because they are absolutely convinced the bass is "tighter" according to "sealed box" advocates. So he sends them an extra plug.

As for me, I'm ECSTATIC about the performance as currently configured (both ports open). Some day, I may try plugging one port to obtain18 Hz. But not anytime soon; don’t think I have much/any material going down that low (even w/DVD LFE material)! And, I’m abandoning the idea of using multiple AR3a’s as "subwoofers" when driven with a huge amplifier fed by an external X-O. A "sealed system" with multiple AR3a’s may theoretically sound better/tighter than a vented one, but listening to the Hsu Sub makes "theory" irrelevant. I like the Hsu Sub a LOT (theory not withstanding).

[ligs]

Here is a link about subwoofer testing.

http://www.hometheat...tests-archived/

Many subwoofers are capable of 20 Hz or below. Interpretation of data is a bit complicated. Generally woofer displacement (excursion x cone area) is a big factor.

I guess I subscribe to AR's motto: Truth in Listening. To listen to really low bass you probably have to go to movie sound tracks, especially action movies:)

[Pete B]

Gerry, I strongly suggest that you try the 18 Hz tuning!

There are HT sound tracks that have very low frequency sound

effects. There was an AES paper on it at least a decade perhaps

2 ago that found 10 and 12 Hz content on something as simple as

Jurassic Park. The bass junkies over on some of the HT boards

look for movies with the strongest and deepest LF content. War of

the Worlds, Black Hawk Down, etc. are just a few of the top ones.

our floor moves at least 1/8" perhaps 1/4" on WOTW with my recent

subwoofer build. You have to turn it up a bit, as I'm sure you know,

to really show what it can do.

My main rig that doesn't need subwoofers has a pair of 12" drivers

on each side tuned to 20 Hz and our boys say that they will crack

plaster, lol! An audiophile friend said it was the tightest, cleanest

bass he ever heard.

[Gerry S]

Gerry, I strongly suggest that you try the 18 Hz tuning!

There are HT sound tracks that have very low frequency sound

effects. There was an AES paper on it at least a decade perhaps

2 ago that found 10 and 12 Hz content on something as simple as

Jurassic Park. The bass junkies over on some of the HT boards

look for movies with the strongest and deepest LF content. War of

the Worlds, Black Hawk Down, etc. are just a few of the top ones.

our floor moves at least 1/8" perhaps 1/4" on WOTW with my recent

subwoofer build. You have to turn it up a bit, as I'm sure you know,

to really show what it can do.

My main rig that doesn't need subwoofers has a pair of 12" drivers

on each side tuned to 20 Hz and our boys say that they will crack

plaster, lol! An audiophile friend said it was the tightest, cleanest

bass he ever heard.

Thanks Pete, I do have all the DVD's you mentioned boxed somewhere. Frankly, I'm AFRAID to play them with the Hsu Sub @ 18 hz. So far, 25hz tuning is "scary enough" for the few days I've been listening to them. My unit is concrete slabs for all boundaries except one. I'm also seated against a boundary wall. So I'm getting almost maximum room gain with little bass loss due to "boundary flexing".

So far, most of listening is with DVD's; think very few music cd's I own/like would "tax" the system. I've also begun viewing streaming Netflix movies; very surprised how much bass there is (sometimes too much).

I'm going to try 18 hz in a week or so (when Poh Ser is here to help me). But for now, my biggest fear is one of my 3 bordering neighbors will come knocking on my door with a complaint....seriously! Poh Ser told me the unit I'm using is one of the "lower end" models in his line. I shudder to think what his bigger systems can do.

As it stands now, I think my system is just coasting; not working hard at all. When I have a more permanent location (sitting away from a boudary), the Hsu Sub can probably then "strut it's stuff" (especially playing the material you mentioned at it's max.. tuned to 18 hz).

[Gerry S]

Here is a link about subwoofer testing.

http://www.hometheat...tests-archived/

Many subwoofers are capable of 20 Hz or below. Interpretation of data is a bit complicated. Generally woofer displacement (excursion x cone area) is a big factor.

I guess I subscribe to AR's motto: Truth in Listening. To listen to really low bass you probably have to go to movie sound tracks, especially action movies:)

Thanks for the link. I admit the data is a little bit overwhelming at first (been a while when I had to view such detailed info). What I've gathered is that all subwoofers will become non-linear at some point when driven to their limits. Fortunately for me, I consider a 3db down point of 30 -35 hz (AR 10, 11) adequate for most of music sources. And my "preferred" SPL limits has been lowered over the years.

I know the "subwoofer wars" among the various manufacturers is quite strong. What I don't understand is how Hsu products can even compete given the relatively very inexpensive selling price of his products. This is my very first "genuine" subwoofer EVER... nothing to compare it too. But I have to question what the other companys offer in "performance" for a significantly higher price.

As to movie theaters, I live 4 miles away fom my "reference theater" complex in Framingham. Thirteen are "high end" John Allen "HPS 4000" equipped, with two more that are "THX Certified" (not John Allen's design). As good as these theaters are, overall , I prefer my own "home theater" experience.

[Gerry S]

Update: think DVD's are gonna be obsolete. Just watched "The Hit List" using "streaming Netflix" with sound being decoded by Pioneer reciever in Pro Logic II mode. Bass thru the Hsu Sub is downright SCARY. And it's still "only" tuned to 25 hz (both ports open). I just can't fathom any significant improvements with 18 hz tuning on vast majority of stuff I've played so far. And to think this is one of his "smaller" products. The more I'm watching/listening, the more I'm anticipating a complaint from neighbors. So far, no complaints. This "deep bass" stuff is getting addictive... can't tear myself away.