Dual Subwoofer Setup

[DAXQ]

I have a small home theater and have acquired two Box sub-woofers from an older LG home theater system. I would like to attach these sub-woofers via an AMP, but am unsure of the best way to connect everything or the size amp to get.
The Passive SubWoofers are 3ohms with Input power 200watts/max 400watts and are identical.
The receiver is a Yamaha RX-V385 with a single SUB PRE OUT

My plan was to add a Subwoofer Amplifier and connect the speakers in series or parallel (was thinking series) but am unsure of the size amp I would need to put in between the Yamaha and the subs. Any suggestions or input would be greatly appreciated.

 

[lovinthehd]

A pro style 2ch amp like those from Behringer, Crown, QSC etc would work well enough although that may be spending too much money on those subs....are these ported or sealed subs? You can use a splitter on the single pre-out easily enough, altho many of the pro amps can do that for you.

 

[DAXQ]

Yes the budget is low (why i'm using these older house set subs instead of getting some powered subs). I doubt they are anything fancy They are:

LG SB95SB-W part of a 5.1 surround home theater system - Particle board box with one side facing speaker and front facing tube/blower. Impedance says 3 ophms, with MAX power of 400W(Program). Dunno if they are sealed or ported (or honestly what that is). Was figuring that since they are 3ohms each and 200watts - that if I wired them in series - it would make them 6ohms and 400watts - so im guessing I need an amp that is capable of taking in the Pre Out and sending that to the speakers?

 

[lovinthehd]

Those subs don't have much in the way of spec in the manual. I'm guessing they're 6 or 8 inch drivers based on cab dimensions and are ported (and I asked as they may need a protective high pass filter so you don't blow them up). They're likely of quite low quality and limited extension (the lower frequency response). Personally I would not buy an amp for them at all but would aim at real sub(s). What amp were you thinking about, tho?

 

[DAXQ]

Had no brand in mind - just looking for low cost and a way to make it work. There are cheap FoSI Audio mini sub amps on amazon or even considering some of the auto sub amp's like boss or planet audio to run up to a 1000watt amp if needed and wire them however they would work best. Just trying to keep the solution cheap and simple. I replaced a LG home theater system with the Yamaha - as the home theater did not have enough HDMI's and was failing in other ways - but in return after purchasing the Yamaha - I also had no way to run the sub's after I realized the Yamaha only had a PreOut for the sub - & not a wire connection (did not due my homework). So while trying to figure out to hook this old LG sub to the Yamaha, I stumbled across a second identical one and now i'm just trying to cobble it together to work - maybe next year Ill look to start replacing the speakers for this set up and getting into something more respectable for the Yamaha.

 

[lovinthehd]

Even two of the Fosi amps would be less expensive than the pro amps I referred to and for those subs perhaps even just one would likely work well enough. Boss and Planet Audio have home amps? Only saw car amps from a brief look and you'll likely have issues powering such. I wouldn't throw too much power at them either. In either case I'd want any amp you get as having other uses as you improved your system...

 

[DAXQ]

You are correct - not home amps, can get a 12V 10amp switching power supply easy enough to power a planet audio tr1500.1 though. Figured it should be more than enough to power these subs and looked like they give a few more tweaking knobs to try and hone it in.

 

[DAXQ]

So I was actually thinking PreOut from Yamaha - Y Split the RCA for Red & White input on the TR1500.1 AMP. Then wire the speakers out from the tr1500.1 to the speakers just not sure if it would be better to go parallel, or serial on the SUB's and mount them either side of the projector screen. Also unsure if 1500 is too much - could look for an 800 or 400.

Or using the Fosi, maybe getting two - one for each sub independently back to the Yamaha RCA Y split out of the PreOut.

 

[DAXQ]

Currently have a small Kinter MA170 18W mini Amp I had on hand for testing - it is actually driving both subs. When I have one sub in each channel, it gets warm/hot. If I put both subs in one channel and wire in series - it does not get as hot, but also seems a little less subby.

More Subby - gets hot

Less subby - stays cooler.
Over all the whole things (to me) sounds kinda tinny and the vocals tend to get washed out no matter what I play. Aside from trying the 200 watt amp to drive the subs, is there something else I am doing wrong with this set up or are the speakers just mismatched for the Yamaha? I believe in reading the Yamaha specs - for the 4 ohm speakers in place - it should be sending 160watts dynamically, but not totally sure.

 

[mazersteven]

For what you're going to spend on amps and the capabilities or performance of those subwoofers in my opinion throw those things out and get a pair of these

Home

Dayton Audio SUB-1200 12" 120 Watt Powered SubwooferDayton Audio SUB-1200 12" 120 Watt Powered SubwooferAdd thrilling low-frequency effects to your home cinema experienceThe Dayton Audio SUB-1200 12" powered subwoofer system is the perfect addition to any home theater system. This powered sub...

www.parts-express.com

 

[DAXQ]

Those look great, but out of stock and 150$/ea that would be down the road for me.

 

[NINaudio]

That little amp gets warm when you run it in dual channel because your running it with subs whose impedance is below what that amp is rated for and it stays cool with both in series because you're only using one channel and it's see a larger impedance. Lower impedance loads will generally draw more power from an amp, while higher impedance loads draw less power.

 

[mazersteven]

Those look great, but out of stock and 150$/ea that would be down the road for me.

Back in stock on 11/20

 

[DAXQ]

Thanks for the info guys, really appreciate it.

Yes I figured that is why I wanted to try running them in series to get 6 ohms rather than 3 & 3 - and I think running it in series is good for the ohms, but 18 watts isn't enough to make em sub - so think i'm gonna get the 220w fosi amp and keep them in series to see what it does.

Even 11/20 will still be too rich for my bank book - will definitely keep them in mind when I can afford it.

 

[mazersteven]

I still like the Dayton subs but based on your comment here's another option you might be interested in these.

Monoprice 12in 150-Watt Powered Subwoofer, Black - Monoprice.com

When you want your bass down low, you need a subwoofer as part of your home audio/theater system. Monoprice™ has the basses covered with this 12 inch, 150 watt (RMS) Powered Subwoofer

www.monoprice.com

 

[DAXQ]

I would hold out for your first recommendation - i've just shot my yearly on the receiver - now just trying to make what I got work as thriftily as possible.