Will the HSU STF1 do the job?

[gcc]

I have a pair of bookshelf speakers on stands (KEF Q15) powered by a Sansui... 20 wpc amp (not enough watts?) The speakers are 2-way, bass reflex with a Frequency range of 50Hz - 20kHz, the sensitivity is 91dB with amplifier requirements of 10-100W. The impedance is 6 ohms. My living room is 12x13 (smallish by most standards) I listen (mostly, but not always) to classical music that occasionally requires deep bass (for those who are familiar with classical music, "think" 3rd movement passage of Vaughn Williams' "Sinfonia antartica"... or Mahler's sym 8) Okay... that's the facts that (I'm guessing) might be helpful to know. I don't know "jack" about subs or high-fi, in general...

A review by Sound & Vision (see HSU products page for STF1) stated (regarding the STF1): "meaningful volume all the way down to 25 Hz" But, HSU's specs indicate that the bass extends +/- 2 dB to 32 Hz. What's the deal with that? And should I be considering ANY sub, considering I'm only working with a 20 wpc amp? The HSU has its own amp, so it shouldn't be a draining what little power I have, no? Anyway, the small STF1 fits into my budget pretty well, but if there are other factors that I need to consider, please tell me what they are.

Thanks!

[tedjack]

If you can do an extra $50.00, look at the STF-2. I own one and you will love it!

[gcc]

If you can do an extra $50.00, look at the STF-2. I own one and you will love it!

What I like about the STF-1 is that it's the smallest of the subs (translation: least ugly :) and the silver model is a clearance item being sold for $239.00. So if I get the silver color, that would be a $110 difference. That's significant to me.

The pics look like the sub has spikes on the bottom.... 1) is it okay to use them without spikes and 2) can the sub be used turned on its side? Also, I hope to get some input as to wheather the STF-1 can be used with a low-powered integrate amp (20 watts per channel)

Thanks for your input!

[LeonardR]

Your speakers are down three decibels at 50 Hz (if you believe the specs are true and relevant for your room and placement).

See http://www.listenhear.co.uk/general_acoustics.htm

You are not getting the low end of the symphonic instrument range not having a sub. You will NOT DIE without it. A small percentage of music is written for the lowest notes an instrument will play. However, if you can afford a sub, you will appreciate it on a LOT of classical music.

A sub would make your bookshelf speakers sound clearer and probably be more accurate by removing the strain and distortion from trying to deliver the very difficult bottom frequencies. The crossover frequency of your bookshelf speaker is 3,300 Hertz -- If you look at the high end of the ranges on the link above, the large speaker of the two in the KEF Q15 (driven by your 20 wpc amp) is playing virtually all of the important sounds.

Your room is not huge -- if your system plays as loud as you want, and you like the quality of the sound, you might not want to spend big to make improvements. The biggest strain on both your amp and speakers are the frequencies below 120 Hertz. A powered sub does not tax your speakers and amp -- rather it frees them provided you can redirect the low frequencies to the amp in the sub.

I presume your amp does not have a subwoofer-out connection and bass management (i.e., the amp redirects the low frequencies to the sub). Some amps have a low-level center channel output which you can input to the sub. Probably better in your situation, you can connect the amp speaker wires to the high-level inputs of a sub and use the crosover in the sub to pass the higher frquencies on to your bookshelf speakers. If you can place the sub between the bookshelf speakers, you should not be able to locate the sound comming from the sub up to about 120 Hertz (a good starting crossover setting for your amp and speakers).

As to the question of whether the STF-1 is enough ... that is for your judgement of your objectives and budget. It helps if you listen to the music and not the equipment to keep from getting obsessed. It also helps if you can listen to several systems that include subs. Keep in mind that most of the posters on sub forums are interested in the movie soundtracks where virtually ALL of the sound are artifically created by sound engineers. However, lots of people invest more than the cost of a pricey car on a two-channel audio system for classical listening, but you get diminishing returns as you throw more money at the "problem".

Good luck!

[gcc]

<snip>

A sub would make your bookshelf speakers sound clearer and probably be more accurate by removing the strain and distortion from trying to deliver the very difficult bottom frequencies. The crossover frequency of your bookshelf speaker is 3,300 Hertz -- If you look at the high end of the ranges on the link above, the large speaker of the two in the KEF Q15 (driven by your 20 wpc amp) is playing virtually all of the important sounds.

Your room is not huge <snip>

I was surprised when I saw that the crossover was 3,300 Hz. That seemed really high considering that, according to the chart from the url you supplied, classical music *generally* falls between 40 hz (double bass) and 3.5 Hz(the highest notes of the violin).

Since, both my speakers have the same specs and cabinet size, what do you mean by saying "the larger speaker of the two"?

Thanks for your crossover-setting reco (120 Hz). I'm not sure how to do the setting, but I assume a manual will come with whatever sub I choose and explain it. At this stage of my ignorance I'm thinking that most subs offer crossover frequencies that can be "dialed-in."

Indeed I am not one who gets obsessed with equipment. Nor am I interested in a sub for movie enhancement. An inexpensive sub ($130-$275) that leaves a small foot-print and is designed for "musicality" is the ticket.... a little something that will take-over where my KEF's leave off (bass-wise) A 10 inch woofer-size would probably be ideal in my small living room. Actually, if it's taken into consideration that it extends into my 11x11 kitchen, it's larger than I initially stated. A half-high counter/wall (think bar) separates the two rooms. Naturally the separator doesn't go all the way across or there would be no entry into the kitchen from the living room, or vice-versa. Anyway, I appreciate the time and effort you put in to help me. Many thanks!

[LeonardR]

I meant that your KEF Q15 is a two-way system, i.e., there are two drivers in each box. The larger driver (woofer) handles the frequencies up to the crossover frequency and the smaller driver (tweeter) takes over above that.

A powered subwoofer's electronics usually has a crossover filter that passes the frequencies above the crossover setting to the main speakers and captures the frequencies below the sub's crossover to the sub's amplifier.

Hsu Research (like most manufacturers) has their owner's maunal on their web site. The link to the manual for the STF-1 is on the product description page on the right side -- http://www.hsuresearch.com/products/stf.pdf -- the Method B connection section shows how to use the sub with an amp that does not handle the crosover up-stream from the main stereo amp.

There was a thread on the AVS forum last year on the best sub under $300 and the STF-1 very well regarded and was mentioned as being more "musical" than the others.

The published specifications by Hsu Research show mesurement taken in a large open area (parking lot). That is where the objective measurements of the STF-1 were +/- 2 dB at 32 Hz. The accoustic energy radiates through half of a sphere. Measuring this way is objective and repeatable by others. Reviewers listen in rooms where the accoustic energy is focused by the walls. Putting the sub in a corner would add 9 dB of gain in the bass frequencies over the parking lot measurements (an 8th of a sphere vs a hemisphere for the energy to try to fill). Room gain and less sound volume than the -2dB of the spec is why a reviewer can say they heard "meaningful" bass at 25 Hz. The corner may not be the best location in your room, however. Rooms are different in geometry and absorbtion of accoustic energy, so frequency response in one person's room will not be repeatable in a different room.

I suggest you call Hsu Research and let them ask you questions that would verify that you are making the correct choice for YOU.

[gcc]

I meant that your KEF Q15 is a two-way system, i.e., there are two drivers in each box. The larger driver (woofer) handles the frequencies up to the crossover frequency and the smaller driver (tweeter) takes over above that.

Now I understand. Thanks

Hsu Research (like most manufacturers) has their owner's maunal on their web site. The link to the manual for the STF-1 is on the product description page on the right side -- http://www.hsuresearch.com/products/stf.pdf -- the Method B connection section shows how to use the sub with an amp that does not handle the crosover up-stream from the main stereo amp.

I see. Easy enough.

The published specifications by Hsu Research show mesurement taken in a large open area (parking lot). That is where the objective measurements of the STF-1 were +/- 2 dB at 32 Hz. <snip> Room gain and less sound volume than the -2dB of the spec is why a reviewer can say they heard "meaningful" bass at 25 Hz. I suggest you call Hsu Research and let them ask you questions that would verify that you are making the correct choice for YOU.

Okay.... I understand that now....
moving on, and this may be poor Etiquette to be posting on a HSU forum (I'm trying to be objective for my own sake!) Is the HSU STF1 sub really the best bang for buck considering the specs?

HSU STF-1 (which has great consumer reviews)
Amp power 150 Watts
Bass extension +/- 2 dB 32 Hz
Woofer size 8 Inches
price - $299


Compare that to Sony's SA-W3000's 12" model, which also has great consumer reviews. Right away I noticed that the Sony has a larger speaker and goes down lower:

(Sony SA-W3000): 12" 180-Watt Subwoofer
Frequency Reponse: 20 Hz - 200 Hz
price - $116.49 (at etronics)

Comments are welcome.

[LeonardR]

Trying to get the best value for the money is not poor etiquette ... especially on the Hsu Research site. Hsu made his reputation by creating a better sub at a fraction of what his traditional competitors were offering.

There have been many occurrences of manufacturers that could not or would not do the R&D to achieve superior design and execution that can "stand on the shoulders" of the good designers to deliver a better product than they previously had at an attractive price to consumers. We consumers like that. The government also appreciates it since they replaced the "cost of living" index with the "consumer price index". The rising cost of food shelter and energy over the decades has been buried in the falling cost of technology products.

I have not heard either of these subs. I think it unlikely that you will find a reviewer who has made a direct comparison. The reviewers I pay attention to are the ones who use instruments to measure distortion as well as frequency response. Cabnet resonances and port noise will be important.

Your original post indicated you wanted the sub to be small. GOOD, SMALL, CHEAP ... you only get to pick one for sure and then a fraction of the another objectives. Giving up small and good ... yes, you should be able to get cheaper. Your post sounded like you wanted a new-under-warranty sub. If you can handle larger, there are more options, including a used tube sub.

http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=8198552921665089196 -- I believe the Sony does not have speaker-level inputs. Line level input only means you probably could not use it with your Sansui amp. Even if the Sansui has a center out you could plug in, you could not keep the bass frequencies away from you bookshelf speakers. The Sony SA-W3000 does not have a crossover built in - it expects some other device to be providing all of these features.

If you were a teenager looking for a thud-Thud-THUDing bass line to mind-numbing music, it would take a lot less to satisfy you. To get music out of a tourture test like Sinfonia Antartica on a tight budget will make your research more difficult.

Good luck

[gcc]

Trying to get the best value for the money is not poor etiquette ... especially on the Hsu Research site. Hsu made his reputation by creating a better sub at a fraction of what his traditional competitors were offering.

Thanks for understanding..., and to those who take the same stance as you do.

http://www.sonystyle.com/webapp/wcs/...52921665089196

I notice that Sony Style, which looks to be an online outlet for Sony, sells the SA-W3000 for $250. They're not giving out any deals; their authorized dealers are underselling them. Etronics, for instance, sells the same product
for $116.71

http://tinyurl.com/68xv3z

I believe the Sony does not have speaker-level inputs. Line level input only means you probably could not use it with your Sansui amp.

According to sonystyle, the SA-W3000 does have speaker & line level inputs (click on the "features" tab of the url you supplied).

Related Question: Does the term "speaker level inputs" mean that you can plug the sub into the back of the amp via an RCA chord? And, does "line level" mean you simply connect as you would a speaker (via speaker wire)? Sorry, I'm so ignorant about this, but I'm learning... albeit out of necessity ;) (Thanks to you and others... I certainly admire and appreciate the patience required of those who have educated me - Three cheers for public education :D

Even if the Sansui has a center out you could plug in, you could not keep the bass frequencies away from you bookshelf speakers. The Sony SA-W3000 does not have a crossover built in - it expects some other device to be providing all of these features.


I have high and low filter switches on my Sansui... would that keep away unwanted frequencies? hmmmm, more ignorance on my part?

If you were a teenager looking for a thud-Thud-THUDing bass line to mind-numbing music, it would take a lot less to satisfy you. To get music
out of a tourture test like Sinfonia Antartica on a tight budget will make your research more difficult.

I hear you loud and clear... 'thud-Thuding' isn't my thing. It's difficult for me to know whether a subwoofer is "good," in the sense that I would think of it being that, by simply reading consumer comments on any given subwoofer. Many of them are into home-theater or ones who enjoy relatively uncomplicated music. That's great, I'm not wanting to seem elitist here, merely pointing out that I'm not looking for a sub for HT thrills or for music that is primarily played on electric instruments.

Many Thanks