Beginner advice (1 Viewer)

Hi, this is my first post and I'm a newbie to HT stuff.

For a little introduction, I'm 18 years old and just recently became interested in "nice" speakers... Since I'm not so rich, I purchased a set of Klipsch ProMedia 5.1 speakers (for $358)...

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What I want to do is build a subwoofer to extend the low-end, if possible. I connect this 5.1 set of speakers to my computer with 3 stereo minijacks and the 3rd one is Center/LFE...

Is it possible to split the LFE to both inputs, and what connections would I have to get?

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The subwoofer I am planning to build is a "sonosub" with a 12" adire shiva driver and a 250 watt parts express amp. Any suggestions on cubic feet for this? Adire sells a kit with a grill, connectors, and port/etc

My budget is around $300 maybe a little more

Yes, you will be able to split the LFE signal out to both the ProMedia and your new Sonosub.

Firstly, use a stereo miniplug (3.5mm) to twin RCA lead out of the computer's soundcard. This splits the Centre off the LFE. Then connect a female-female joiner to the Centre RCA (You may not know which one - just choose one as we can swap it over later if necessary.)
Then connect a RCA to 3.5mm stereo socket lead from the centre RCA to your current Promedia stuff. Connect the other RCA from the first lead to your new sub amp. You may need a couple of gender changing plugs - I don't know what is available in the US, but all the above is available in New Zealand, so you should be OK.

If you don't mind manufacturing your own cable, this can be done as well.

As for volume of enclosure, decide if you wanna go ported or sealed, and what sort of bass sound are you going for? (Low and flat, high impact etc. etc.)

Hope this helps.

Here's some enclosure suggestions from Adire's site:

http://www.adireaudio.com/tech_papers/shiva_apps.htm

Thanks for the input!

I'm looking for rumble in movies but clean bass for music, if this helps you decide what is best for me.

I believe the promedia sub farts at loud volumes, hehe, so maybe I can relieve it with a new sub helping.

Punchy bass sounds good to me, but I also want good rumbles in movies

Also, I don't want a sonosub the size of a water heater

Jonathan,

Can I still use the sub in the ProMedia? The picture of the back of the sub is here: http://www.3dsoundsurge.com/reviews/...51sub_rear.jpg

I'm guessing the new sub amp has RCA out as well. So, then I would need 1/8" stereo male -> male/female RCA from source, male RCA going to new sub amp. Then another 2 male RCA -> 1/8" stereo male, one RCA from new sub amp and the other continuing the Center to the other sub/amp.

I just need to find the wires now, if this is correct

Yep that's right.

If the new sub has no outputs, you can use a y-splitter to split your LFE RCA into two.

You may (likely) find that the Shiva (or whatever) outperforms the other sub so much as to not bother with it.

cool!

I just had a brilliant idea...

I can get 1/8 mini-> male RCA splitter, 2 of them... then just link the Center with an RCA "coupler"... should be the simplest solution, right?

Is there any static noise caused by this in subwoofer application? :b

I still am really new to this and don't understand how the volume affects punchiness and loudness, etc... Would you still recommend building a sonosub (I thought that was the easiest to make)?

I have ProMedia 4.1's. The sub that it comes with doesn't deserve to run with a sub like the Shiva. Don't even bother running both of them. Don't get me wrong. For a sub that's part of a PC speaker set it's great, but below about 30 hz the output drops like a rock and the output above 30 hz isn't very articulate.

I'm afraid that opening the sub will void warranty, and these things are likely to blow out (if you do a little research).

I think I could just leave it disconnected or lower the volume of it. By the way, the ProMedia 5.1 sub/amp is supposed to be better than the 4.1 set.

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I'm guessing PE is parts express Is the package with the remote and extra controls worth it?

Thanks for the help

I found something cool at PE.

http://www.partsexpress.com/pe/pshow...=300-739&DID=7

It's basically a kit with the box already made. 10" titanic

Looks like a reasonable price but I don't know how it compares to a 12" shiva?

Should I get gold plated stereo1/8" to RCA splitters?

THANKS for any answers...

I recommend going with the Shiva in a 18"x32" sonotube, 4"x12" port tuned to 21.7 Hz. This will give you nice flat low response without a huge footprint.
Shiva - $125
S-tube- $20
Amp - $120
Port - $14
and depending on your finish, glue, paint, etc, it's possible to come in pretty close to $300. Not bad for an excellent performer!

ok thanks

so does parts express sell that port in the kit?

and i can get the sonotube free

I was referring to the Precision Port Kit here.

ok thanks again!

I saw they sold a kit with a grill, internal wiring, and a post for the terminals... should I get that with the 4" port?

hmm I can't find that kit anymore :frowning:

I'll just get the 4" flared port you linked, I dont need a grill.

I do need to find a guide that I like though

Hey Joel,
If you're want to save a little money, check out the Blueprint 1201. It has similar output capabilities and is only $70.

www.audioliquidators.com

I'm not familiar with the PartsExpress plate amp, but doesn't it have a built in stereo crossover with a preamp high-pass out ? I ask because most subwoofer plate amps offer this. If it does, you can plug in your new shiva sub directly into your centre/LFE, and then plug your Klipsch's centre/LFE into your plate amps high-pass output. This way your plate amp will crossover the signal first (at 80Hz for example) and send everything above that to the Promedias. I would keep the Promedia sub in the setup, as I don't think you really want to crossover your Shiva at 120Hz (which is what the Klipsch set does). Here is an example of the signal path using 80Hz as a sample x-over point for your Shiva:

1) LFE/Centre output to PE-Plate amp
2) PE plate amp's crossover sends everything below 80Hz to it's amp section then to your Shiva with 250W
3) PE plate amp's crossover sends everything above 80Hz to it's line level output
4) Your klipschs receive the signal from your high-pass plate amp output, which is the same LFE/Centre signal without any info below 80Hz
5) The Promedia's built in crossover will then send everything above 120Hz to the satellite speaker, and everything below (ie: between 80 and 120Hz) to it's (Promedia) sub... This should be an easy load for it to handle.

Or am I expecting too much from the plate amp?

Nice info there, Rob. I was wondering what that line level output was... I'm not very familiar with high-pass crossover stuff... but picking up on it. I think I would keep the ProMedia sub either way, but turn down the sub volume if needed.

So, for this wiring... I am trying to figure out what connectors and adaptors I will need, and I don't want to spend $50 on cables for my computer setup

I checked the PE 250 amp details and it mentions High pass filter for satellite speakers!