[gychang]

I have a PC satelite speakers, using 3" fullrange DIY speaker featured here with t-amplifier clone.  https://www.youtube.com/watch?v=m4DjSm-p5rY

I mostly use it for youtube and small group-jazz, guitar listening, not into rock, or orchesteral music.  Occasionally I miss little bit of bass with serious jazz quartet etc.  I have some tools and extra t-amp (Lepai). 

1.  Is there a small diy sub perhaps from PE I can make and drive it with a separate Lepai?.  What kind of "cross-over" will I need?, it will mean I have to turn on 2 amps each time?
2.  will a used small "craighlist" powered sub do?
3.  I see ebay with 2.1 amps, is this a cheapest solution?

thanks

[JLM]

Video shows table top setup, but you mention PC use.  What is the primary application?  Many report that in desktop (near-field) use, subs have a difficult time integrating with the speakers due to high crossover frequency needed to accommodate the smaller desktop speakers, relative difference in distances of speakers versus sub, and sub location under or to the side of the desk.  Have you tried to bump up the bass output from the computer tone/equalizer controls?

Don't know how low your speakers go, but a low crossover frequency is desirable.  80 Hz might be ideal, 120 Hz is about the upper limit before you begin to localize the sub (hear where the sound of it is coming from).

BTW, HSU makes a "mid bass module" that works well with small speakers.  It's not marketed as a subwoofer (only rated down to 50 Hz), but uses a light weight cone to better integrate at slightly higher frequencies.

[gychang]

Video shows table top setup, but you mention PC use.  Have you tried to bump up the bass output from the computer tone/equalizer controls?

Don't know how low your speakers go, but a low crossover frequency is desirable.  80 Hz might be ideal, 120 Hz is about the upper limit before you begin to localize the sub (hear where the sound of it is coming from).

BTW, HSU makes a "mid bass module" that works well with small speakers.  It's not marketed as a subwoofer (only rated down to 50 Hz), but uses a light weight cone to better integrate at slightly higher frequencies.

The speakers are at PC same level as the monitor, mainly for background music and youtube etc.

I am hoping to be able to setup the subwoofer on my shelf same level as the satellites.  Not using the equalizer and want to avoid using it...

[Phil A]

The sub would likely perform better on the floor near the corner

[Phil A]

I have an old RCA 50W sub I use in the office when I listen to the sound via the speakers.  I have an old A/V receiver and use that for the crossover.  One could also use the line in and line out speaker level jacks of the sub

[Phil A]

I'm not using the below speakers in my office any longer.  The pic is from my old house but illustrates where I have the sub.  The sub is behind the filing cabinet on the right and on the floor firing towards the desk.

[neekomax]

Video shows table top setup, but you mention PC use.  What is the primary application?  Many report that in desktop (near-field) use, subs have a difficult time integrating with the speakers due to high crossover frequency needed to accommodate the smaller desktop speakers, relative difference in distances of speakers versus sub, and sub location under or to the side of the desk.  Have you tried to bump up the bass output from the computer tone/equalizer controls?

Don't know how low your speakers go, but a low crossover frequency is desirable.  80 Hz might be ideal, 120 Hz is about the upper limit before you begin to localize the sub (hear where the sound of it is coming from).

BTW, HSU makes a "mid bass module" that works well with small speakers.  It's not marketed as a subwoofer (only rated down to 50 Hz), but uses a light weight cone to better integrate at slightly higher frequencies.

In my system, which is very different from the one being discussed, I personally feel that above 70 hz I can start to localize the sub, which is not located right next to the speakers, because I use it mainly to smooth out room modes.

Best computer speaker set I've ever heard is the Klipsch Pro Media 2.1. If you're set on using your DIY speakers, seems to me that craigslist and eBay are full of cheap and cheerful subs.

The Hsu mid bass module is an interesting product.

[srb]

If you have a Tripath TA2024 the speaker grounds are isolated so you shouldn't make a speaker level connection to a subwoofer whose speaker level inputs have a common ground.

If you don't have a pre out on the amplifier you may be able to add an isolated speaker level to line level adapter to use the line level input(s) on a subwoofer.

Your solution #3, might be the best, replacing the amplifier either with one that has a subwoofer line level output or a 2.1 amp (if you can find or DIY a passive subwoofer).

Of course adding two independent powered subwoofers with speaker level inputs would also solve that potential problem.

Steve

[Doublej]

An almost subwoofer? How about one of these?

http://www.hsuresearch.com/products/mbm-12mk2.html

[charmerci]

These are 13"x13"x15" deep

http://www.parts-express.com/dayton-audio-sub-800-8-80-watt-powered-subwoofer--300-627

[megabigeye]

If you have a Tripath TA2024 the speaker grounds are isolated so you shouldn't make a speaker level connection to a subwoofer whose speaker level inputs have a common ground.

If you don't have a pre out on the amplifier you may be able to add an isolated speaker level to line level adapter to use the line level input(s) on a subwoofer.

Your solution #3, might be the best, replacing the amplifier either with one that has a subwoofer line level output or a 2.1 amp (if you can find or DIY a passive subwoofer).

Of course adding two independent powered subwoofers with speaker level inputs would also solve that potential problem.

Steve

I'll second this.  You should definitely be careful when hooking a class-T amp to the speaker level inputs on a sub.

I don't know that it's really what you meant when you said 2.1 amp, but I'll also mention that class-T amps are far superior to the Klipsch ProMedia 2.1.  I've owned three Ts and they're all head and shoulders above the ProMedias, which I used for several years.

...On the other hand, I do have a nice set of Limited Edition Star Wars Klipsch ProMedia 2.1s I'd be willing to sell for cheap if you want them.

Oh yeah, almost forgot: I'd also probably stay away from cheap "craigslist" subs unless it's something you're familiar with.  Crappy subs sound crappy.  Of course, if you find a good used sub for cheap, why not?

[dragoonxp20]

If you're into a little DIY and soldering, you could make an active line-level crossover.

http://www.linkwitzlab.com/filters.htm#2

Something simple like that wouldn't cost all that much.
12V DC power supply
3 op amps
Some low power caps and resistors
Wire
Perfboard
RCA jacks

You can modify it to be variable frequency.
Alternatively you can just keep the high side and use the built-in crossover on the sub.


As for what sub, for a low cost setup, go with either a Dayton sub from partsexpress or some other mass-produced sub. You probably won't be able to DIY a sub for the cost of some of them.

Quick estimate of a cheap DIY sub:
$40 for MDF
$20 for paint/primer/clearcoat
$30 for subwoofer
$40 for amplifier

Already looking at over $130 + labor vs a finished sub for either about the same price or less.

[neekomax]

FYI: For one more day, you can get one these dual 6.5" Pinnacle subs pretty cheap, $160. They are small as all get out, but push air more like a 10"er. They're really good. Source: I have one, just ordered two more.

http://electronics.woot.com/offers/pinnacle-dual-6-5-300w-powered-subwoofer-14?ref=cnt_wp_1_30

[hdspeakerman]

http://www.parts-express.com/dayton-audio-dc160-8-6-1-2-classic-woofer--295-305
You could probably use something like this Dayton Classic 6.5" woofer with a plate amp. 
The people on the forum would help you with the size box.  it has good bass and would work with a PC set up.

[hdspeakerman]

http://www.parts-express.com/dayton-audio-sub-650-6-1-2-60-watt-powered-subwoofer--300-625?utm_source=Retail&utm_medium=Email_Newsletter&utm_content=300-625&utm_campaign=email031915B