Inexpensive Quality Subwoofers
Apr 8, 2007 at 4:03 PM Thread Starter Post #1 of 19

classicalguy

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I have two subwoofers: a very old 10" parts express job, and a recent 8" Athena sub. The parts express does not sound musical. It grunts and groans, but no real tight sound. On the other hand, the Athena sounds quite good with cello or string bass - very tight and natural. However, it clips and distorts terribly when playing the low notes of an organ. Is there such a thing as an inexpensive sub that sounds good and tight with music while producing organ notes without clipping? Alternatively, I could live without the low organ if it didn't make very audible and unpleasant clipping noise - I would rather that it not produce the notes than clip like that.
 
Apr 8, 2007 at 5:42 PM Post #5 of 19

Thelonious Monk

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Quote:

Originally Posted by firefox360 /img/forum/go_quote.gif
Well the SVS subwoofers are usually regarded as one of the great bargains in terms of the non-DIY subwoofers out there. There are probably a couple of Head-Fiers that have one of their cylindrical ones that could give you a better impression.

http://www.svsound.com/



Quote:

Originally Posted by micesol@yahoo.co /img/forum/go_quote.gif
Hsu


yes. i prefer hsu, their stf-1 is just as good as svs's cheapest box sub and $200 cheaper (@ $249). they're truly a no-frills company, and produce some of the few box subwoofers that can move air down to below 20hz without being gigantic. if i don't go hsu with my nearfield setup it will have to be something $600 more (like the earthquake supernova mk iv, haven't heard it yet) to actually get much better performance...

av123 makes a few great cheap subs too, $200 for the x-sub, $500 for the cheapest rocket sub (haven't heard the latter)

i loooove subwoofers. i can't have a speaker setup without one, i need earth-shattering bass, and they improve the midrange by putting less strain on your mains. still need to convince my dad to let me ruin the closet and try ib, though...
wink.gif
 
Apr 8, 2007 at 10:03 PM Post #8 of 19

Thelonious Monk

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Quote:

Originally Posted by classicalguy /img/forum/go_quote.gif
What does the Hsu STF-1 do when fed a low signal (like low organ notes). Does it clip and distort like my Athena 8" sub?


depends on what kind of organ we're talking about. some organs go down to 8hz... that's only felt though, and the standard for pedals on an organ is the last octave: 16hz to 32hz. the stf-1 is just too small to reach this lowest octave powerfully, it's at -3db at 30hz. that's still amazing for an 8 incher. if you really want to reach down there you'd have to go further up the hsu line; at $600 you get down to 18hz.

if you know any DIY audio people, you could probably get a great sealed, down-firing 12" to augment your bass perfectly. if not, however, hsu is the way to go. if you want that last octave you're just going to have to spend more money, simple as that. buying two subwoofers, 1 for each channel, might work... talk to hsu about that though, i don't remember if you can daisy-chain two stf-1s.

edit: also, check out the avsforum subwoofer forum. they're all about bass extension and impact there, there may very well be something in your price range that can deliver powerful organ tones without clipping or just copping out.
 
Apr 10, 2007 at 12:55 AM Post #9 of 19

classicalguy

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I appreciate the advice, Monk. What happens to the Hsu 8" when it's fed low notes (say 20hz)? Does it (a) not play them, or (b) clip and distort badly like my 8" Athena? I would prefer (a). I've never had a speaker that made the kind of clipping noise that the Athena makes when I feed it low organ tones. It's painful. However, it really sounds great with ordinary string bass (I'm guessing 50-60hz?).

Also, if I decided to spend more for a bigger Hsu sub, would it sound as good/tight/clean/fast as the 8" with higher notes (say 80-100hz)? Or do the bigger subs, by going down so low, give up musicality on the higher regions?
 
Apr 10, 2007 at 1:41 AM Post #11 of 19

Thelonious Monk

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Quote:

Originally Posted by classicalguy /img/forum/go_quote.gif
I appreciate the advice, Monk. What happens to the Hsu 8" when it's fed low notes (say 20hz)? Does it (a) not play them, or (b) clip and distort badly like my 8" Athena? I would prefer (a). I've never had a speaker that made the kind of clipping noise that the Athena makes when I feed it low organ tones. It's painful. However, it really sounds great with ordinary string bass (I'm guessing 50-60hz?).

Also, if I decided to spend more for a bigger Hsu sub, would it sound as good/tight/clean/fast as the 8" with higher notes (say 80-100hz)? Or do the bigger subs, by going down so low, give up musicality on the higher regions?



when you feed the hsu REALLY deep notes, it will just play them very quietly until it's inaudible in the low 20s. dr hsu has a very good design philosophy, instead of just minimizing harmonic distortion he believes in balancing harmonic, dynamic and inter-modulation distortion. this leads to a great sound on pretty much every frequency his subs reproduce.

as a rule of thumb, the bigger the subwoofer, the worse it does on midbass. i don't think that a 10" or 12" subwoofer will struggle on notes in the 100hz range. however the hsu subs have a crossover that only goes as high as 90hz. right now i'm in an email correspondence with dr. hsu about crossing the stf-1 over to about 110hz, whether it's possible or not. subwoofers in general don't like to operate in the midbass. if you move higher up in the stf range, you'll get the same midbass performance as the stf-1 with deeper bass, just as musical but a bit less zippy.

the thing is, dr. hsu knows this. he makes a woofer made specifically for midbass, so his subwoofers will perform better in the low range. this unit is called the MBM-12. it is made for his higher up subwoofers, the vtf range, and costs $499 factory direct. it has a smaller, lighter driver, and is made to cover the 50hz-150hz range. excellent idea. probably out of your price range though. i'd say that you're fine with a bigger subwoofer in the up to 90hz range. 100hz probably isn't a stretch, but you'd need a different crossover to do that i think. i just sent dr. hsu an email on this, and he'll probably respond before tuesday (he's like ken from alo with his responses, the difference in time between sending my last email and the reply must have been under an hour!) then we'll see. as long as your speakers can get down to that 90hz point, you're in business for sure.

currently i don't own an hsu subwoofer, but i'm putting together a <$1000 2ch nearfield setup. i'm thinking about buying some of his speakers too, he makes a nice horn bookshelf for $125 each, and a htib for $300 ($40 per speaker, single-drivers, watch out insignia!) which are both intriguing. he even recommended a good onkyo receiver to me to make it easier to integrate a sub into the system. it's safe to say, that as my speaker setup gets more expensive, the hsu name will stay with me. such great service and such great prices. i just hope that the stf-1 can reach into 100+hz without straining, that will make this budget system oh-so-much easier. :)

edit: errr... sorry about the tl;dr post. didn't realize i got 4 paragraphs in...
blink.gif


edit2: also, found a good bit of reading on dr. hsu's design philosophy, and the insides of the stf-1.

Quote:

Originally Posted by http://www.audioholics.com/reviews/speakers/subwoofers/hsu-research-stf-1
Hsu Subwoofer Design Philosophy - Dr. Poh Hsu, Hsu Research

The following is a sample list of criteria to keep in mind when designing a subwoofer:

* Cost
* Bass extension
* Maximum output
* Harmonic distortion
* Inter-modulation distortion
* Dynamic distortion
* Size
* Floor space occupied by the subwoofer
* Appearance
* Features
* Ease of use
* WAF
* Music or home theater sub

When designing subwoofers, especially low cost, great value subwoofers, compromising is inevitable. For a given budget, you cannot have your cake and eat it too e.g., you cannot expect a $300 subwoofer to go down to 16 Hz and play at 130 dB with reasonably low distortion. If you want the budget subwoofer to go lower, you have to trade off max SPL.

When we designed the STF-1, we aimed for a sub that is first and foremost, a musical sub with even frequency and power response to as low as is practical for an 8-inch woofer while keeping cost under tight control.

We put in a steep 24 dB/octave low pass filter with a good crossover frequency range - 30 to 90 Hz - so it could blend in with most speakers while getting out of the way quickly so you retain the main speakers' character over its operating range, and at the same time making the subwoofer as non-localizable as possible. A gentle slope would mean the subwoofer reproduced a lot of midrange making the subwoofer more localizable and altering the midrange of the whole system.

While some companies focus on lowering harmonic distortion, we focus on keeping a good balance of harmonic, inter-modulation, and dynamic distortion. We use vented systems to keep cone excursions relatively low to reduce inter-modulation distortion and increase low bass headroom (lower dynamic distortion in the low bass range).

We believe in using designs that avoid using high excursion drivers for three reasons: First, ultra high excursion drivers are not cost effective. They are costly to manufacture. Second is reliability. It's hard to make ultra high excursion drivers that are reliable. Third, ultra high excursion also means ultra high inter-modulation distortion.

We tried to keep the enclosure as narrow as possible so it would not take up too much lateral space, thereby allowing it to fit into tighter spaces.

Design and Construction

The STF-1 is a moderate size powered subwoofer that comes in two basic vinyl finishes, matte black and matte silver, making no pretensions to appear woodish. The review sample was the silver version. My impression was that the finish was unremarkable but competently applied. The unit is rectangular with a tall, narrow aspect ratio, with the intent of making the unit better able fit into available spaces in a room such as alongside a couch or against a wall. Cabinet construction is 3/4" MDF with radiused corners with seams only obvious for the top and bottom panel. The bottom of the unit has metal threaded inserts at the corners to accept plastic cones to support the unit on carpet.

The sub is a downward firing, rear-ported design with an 8 inch cone driver and video shielding. The driver is custom manufactured using a polymer treated paper cone with a butyl rubber surround and a polycotton spider. When I asked Dr. Hsu about these design decisions, he said this construction was selected to provide a long a reliable service life while maintaining cost; and that he has not found significant advantage in using drivers made of exotic materials. The amplifier is a high current BASH (Bridged Amplifier Switching Hybrid) a proprietary amplifier design licensed from a company called Indigo, http://www.bashaudio.com/technologies.htm , that attempts to find a compromise between class A/B amplifier fidelity and class D amplifier efficiency. The STF-1 is rated at 150 watts RMS and has 600 watts of dynamic power.

The amplifier, along with all the controls and connections, are mounted on the back face of the unit. The sub has a three-way power switch with off/auto/on settings, a two-way phase switch with 0 deg/180 deg settings, and a crossover bypass switch. There are continuously variable knobs provided for volume settings and crossover frequency that can be varied from 30 to 90 Hz using a 24 dB/octave Linkwitz-Riley low pass filter. Connection to the sub can be made at line level through a single RCA type line-in or at speaker level with binding posts that include speaker in/out connections. The back panel also accepts a detachable power cable and access to the main fuse.

Inside the STF-1, the cabinet is damped with fiberglass-based material. After removing the woofer, I attempted to remove the plate amplifier, which is mounted with ten wood screws to the cabinet, only to find that it was still securely affixed to the unit. The amplifier section is mounted to the back plate on metal fins secured with additional screws.



 
Apr 10, 2007 at 4:05 PM Post #13 of 19

classicalguy

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Great info Monk.

My speakers are crossed over at 80hz, which is about right. They are very inexpensive small floor standers (really bookshelves in a bigger box), but I am very impressed with the sound. They are Celestion F20DAs, and cost under $200 delivered. They are very attractive - dark apple wood veneer cabinets, and the tweeter is really quite amazing for the price. The F15 bookshelves are even available at Target now under the KEF label. Here is a review of the F15s, which is very accurate based on my impressions of the speakers' performance.

http://www.stereotimes.com/speak033005.shtml

I note that one user compared with the new Paradigm Atom and liked the Celestion better.

http://www.audioasylum.com/audio/spe...es/246530.html

That's saying a lot, because the Atoms have gotten rave reviews. I have not heard the new atom, but the Celestions seem amazing to me for the price (both in terms of looks, build quality and sound). I was playing them quite loud last night, and they did very well. The F20s are a little on the short side, but they put out quite a big image. I was listening to the Brahms Requiem (Telarc) last night, and it was quite beautiful. The speakers disappeared, and the voices were enveloping and articulate. Although it's a metal dome tweeter, I detected no harshness at all. The only problem is that my old Parts Express sub just doesn't keep up - it's slow and dull sounding.

I am using a Panasonic SA-XR 55 receiver, with digital inputs, and I am very impressed with it. So clean, quiet, clear and natural sounding. It needs about 20 minutes of warm up to sound its best. The amps sound much better than my more-expensive Marantz HT receiver. The lowest crossover point on the Pany receiver is 80hz, which is about perfect for the F20s. I highly recommend this receiver to anyone in the market for an HT receiver with those features. Inexpensive and very good sounding with digital inputs. I'm using it as a stereo amp, but it's got full HT capabilities. I do wish they offered lower crossover points (and came out with a high-powered model), but for typical sub-bookshelf setup it would be hard to beat. I have not yet tried bi-amping the speakers, but the receiver offers a bi-amping capability where two separate equivalent amps would be used for the bass and tweeters. The speakers are bi-wirable. Nice gold plated 5 way binding posts.

I have not heard the HSU bookshelves, but I have read criticisms about the horns being honkey. I'm sure they play very loud, which is important to some, but for me what matters to me is naturalness. So I quickly crossed them off of my list.

I have a similar system upstairs: NHT Superzero speakers, Panasonic SA-XR55 receiver, but with an Athena 8" sub. The sub sounds really good with most music (clean and tight sounding, and blends perfectly), but as I said in my opening post it clips and distorts terribly with low organ sounds. The bad clipping worries me because of the potential for damage. I think it's a problem with the amp in the Athena speakers being underpowered. The super zeros are quite good (a famous speaker in its day), but was picky with positioning and can sound a bit harsh if the environment is not perfect. Also, they require a 100hz crossover as there is no bass at all coming out of them. I've been toying with the idea of getting something better for the upstairs system (possibly Ascend bookshelves). But through a lot of trial and error in placement and some foam padding underneath, 've got it sounding quite respectable.

If you are in the market for a receiver, I recommend that you look into the Panasonic - at least if you're using mainly digital sources. I have not tried analog, but I know it's digitizing the analog signal so there is bound to be some loss there.

I'm very intrigued with the idea of the Hsu 8", but this system is in a very large room, so I'm even considering spending a bit more for a 10". I just want to be sure it will be as musical, because (while I like the sound and feel of low notes) the most important thing to me is going to be accurate performance in the 50-80hz range.
 
Apr 10, 2007 at 5:16 PM Post #14 of 19

Max F

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I have the parts express 10 inch sub which is very good at getting the low freq for a cheap price (down to 25hz). I, too, thought its was very slow, bloaty sounding until I learned how to properly EQ the sub. It sounds great now. I used the Behringer Feedback Destroyer (BFD) to lower some bass boom peaks in my room and now the bass is fast with a nice solid impact. For more info please go here: http://www.hometheatershack.com/forums/bfdguide/

BTW, I also have the Pany xr-55 and I love it!
 
Apr 10, 2007 at 9:27 PM Post #15 of 19

warpdriver

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I think for subs, you really should be looking at something from SVS or Hsu. In terms of subs, there is really no substitute for good engineering, and solid build and design, and the SVS/Hsu subs have that. There is no cheaping out to get a good sounding sub that also puts out good output. Even though you can get a lot of bang for the buck from some DIY design, I think there is something to be said about sweating the details that are evident in the bigger names like SVS that have been PROVEN to sound and measure well (with so many reviews and people measuring them)
 

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