New to forum/need help with powered subwoofer

[kanenabel2731]

Hi all!! This is my first time on a audio forum. I have been a avid user on a couple of remote control vehicle forums. I have been reading up doing as much research as I can so I at least don't ask ridiculous questions. As of right now I have a beginner home theater system. Within the next year or two I would like to have a high quality system with loudspeakers made by me. I am really interested in the "build your own speaker systems" hobby. I am fairly mechanically inclined so the idea of wood working plus electronics really has gotten me dreaming up what I can do.

That's all for the background for now.
I would like to make my current system better for now and see how I like the hobby. The components I have now
Sony reciever model# str-dh500
Powered subwoofer sony sa-w17 (question about this one)
Jvc satellite speakers front #sp-ds90 also center
Sony rear satellite #ss-ts20
Sony playstaion3
Philips 52" LCD

The question I have for now is about the Sony powered subwoofer. This sw came off a Sony dream machine system that bit the dust a few years ago. I would like to bypass the sw crossover and just use the receivers crossover. On the back of the sw is only the power cord and the RCA input. On the front is the power button and a selector to choose movie or music. If its too difficult to pull the amp and bypass the crossover then I would at least like to know what freq the movie/music selector crosses over at so I can choose the highest. I do know how to work on circuit boards just never messed with amps or crossovers.
Any help questions or comments very much appreciated.
I know the speakers I have aren't the best but with my future plans I will end up building a speaker kit from pe for the fronts then when money is available I'll build another set from scratch to put up front and move the pe kit to the rear. Thanks for reading and I'm looking forward to be apart of another great forum.

 

[markw]

You can'tgo directly fro te sub output on te receiver to the speaker. You still need a power amplifier between them.

You would have to bypass the crossover but still use the amp in ths subwoofer. Either that, or yank the crossover/amp and put in a new power amp.

Unless you're really, really good are reverse engineerig this stuff, i'd not bother.

 

[Grador]

Welcome to the forum!

To see how difficult [or possible] it is to bypass the internal crossover you're probably just going to have to open the thing up and take a look. Maybe post some pictures of the insides here. I'd guess it's impossible, that the crossover is integrated in with the amplifier.

As for the music/movie selector, I cannot say for sure but my assumption is that it's changing an equalizer and not the crossover. You can attempt to verify this using some free software. Pick any piece of software that has a tone generator in it [REW is a nice suite that has a tone generator and a lot of other measurement tools] and run some sine waves through. Keep upping the frequency until the response starts to taper off, change the setting and repeat.

 

[ParadigmDawg]

Unfortunately, that is not a sub, it's a mid-bass module. I am afraid you will be wasting your time with this project.

 

[BMXTRIX]

I'm just guessing, but I would think that with a cheap system that the included sub/speaker may not have much of a crossover in it, but will allow the designed A/V receiver (Sony Dream System) to handle those duties digitally.

To check, if your current A/V receiver has an internal crossover frequency setting, you can play with that setting and see how it affects the audio you are listening to.

Realistically, you shouldn't expect much with a low end sub, especially one pulled from some other system.

As the above posters stated, this isn't something to put one penny into, and it just makes more sense to work on your own speakers as soon as money allows. Live with what you have.

As a guess, I would expect movie mode to add a boost of bass to the output, while music mode will not add any boost to the bass so it sounds smoother. If there is an internal crossover, it would likely not be affected by that button. The button is a replacement for a 'volume' control.

If there ARE internal crossovers, then they probably are set for the range that speaker can handle, which likely isn't much.

 

[kanenabel2731]

Thank you all for your replies. Your right that I don't want to waste a penny on this system. I do however want to use this system as a way to learn more about this hobby. I would rather make mistakes on a cheap system rather than a expensive one. I do have a few other speakers laying around the house that I can mess with.
I have a pair of Bose shelf speakers. They look like new but I'm not sure about their sound quality. They are very old. At least 20 years. They seem like they are missing a lot in the mid range area.

With your suggestions I'm going to pass on messing with the mid bass module. I have the reciever crossover set at 80hz and it sounds pretty good to me. In a few weeks I'll have the parts express speaker kit and post up pics and probably have a few questions.

 

[Adam]

Welcome to the forum!

I disagree that your Sony SA-W17 is a "mid-bass module." Sure, it's not going to be an awesome dweller of low frequencies, but it is what most folks would call a subwoofer.

The low-pass filter on the SA-W17 is set at 200 Hz per the owners manual. So, in effect, you would indeed be using the crossover setting on your receiver instead of on the sub (I'm assuming that you'd be using a setting no higher than 200 Hz). You can achieve the end results without any need to take it apart. That said, you can always take it apart to learn a bit.