Powered Sub wooker hook up question.. HELP!

First of all, welcome to the forum. You will learn a lot of good stuff here. I learn something everything. As of right now it seems that we both have the same set up. I have the same reciever, and the same front speakers and sub. What you need to do is buy a Y-adapter. You can get one at any electronics shop. Then you use a sub-cable coming out of the .1 channel in your reciever, hook it up to the single side of the Y-adapter, then connect both the other two sides of it into the L/R channels of the sub. Haven't bi-wired yet, or even thought about it. I also cannot answer your question about the bi-amping.

The crossover sets the highest frequency that the sub will play. The rest is then sent to the fronts.


RMS= root mean square. The RMS is the pure power average. If you have a sine wave representing the power, RMS would be a square wave imposed over that (sort of). When you are buying stereo equipment RMS is the important number. It is .707*peak power which gives you the average power output. I know that is kind of confusing. If you do an internet search on RMS values, it could help. It is an electrical engineering term.

Hope that helps
BG

eclypse,
First, welcome... Glad you are liking your 70's. Very popular model 'round here, that CC and others just put into the reach of many...

Let me see if I can address a couple questions not answered yet and amplify some others...

You're nearly wired the Club Polk way. Tends to be favored here as once the sub's volume is calibrated, it puts the sub managment completely into the hands of the AVR. So you get both convenience and repeatability. Either John's or BG's suggestion puts you all the way there. Which you choose is up to you.

BG's way with the Y-connector yields an added 3 dB output, but in your condo situation you probably can't use that anyway, unless you throw a party for the neighbors. This way does require you to set your sub's filter to maximum to avoid the dreaded double filtering. John's way bypasses the filtering as he mentioned.

If an AVR has a fixed sub cross-over, 80 Hz is as good as any, and ought to be right for the 70's.

John also rightly points out that the sub would add no amplification to the speaker line levels were you to rewire that way, the "Polk way" as it's referred to often in the Club.

BTW, the Polk way does not preclude bi-wiring or amping. To do this just run the high's wire directly to the mains, while routing the lows via the sub...

Crossovers...
Most speakers utilize two or more different drivers. To avoid gaps in reproducing sound, the ones selected overlap in the frequency range they individually reproduce. But this leads to undue emphasis in the region where the overlap occurs as the two drivers output are additive. The crossover is added to the circuits to eliminate this emphasis by rolling off the highs sent to the low freq driver and the lows to the high freq driver. Designed properly for the specific drivers used, the resulting sound level pressure (SPL) through this transition area is flat.

Your sub's filter point means that it plays frequencies at that setting and below, with the frequencies above that point routed to the speaker line out connections.

As for the centers and rears, what they play will be determined by the AVR's settings. If they are set to "small" then the AVR will route information above the fixed 80 Hz set point to them. If set to "large" they would get full signal. Most would suggest setting them to small.

Oh and RMS... some here, e.g., Russ, will tell you that Watts RMS is a misnomer. And strictly speaking he is correct. An amp's output voltage differential is best characterized in RMS terms by the calc BG mentions. Some use this value in a calculation of the amp's power and call it Watts RMS. once this was a very common spec, but more often now you'll read about continuous power rating, which is a better measure of amp performance.

I swear I tried to reply earlier... glitch, I guess

Originally posted by eclypse
Which is lower fequencies for the sub? Is it 120 or the 40? Thats about the only thing that confuses me still.. Lower is the lower number and higher is the higher one? So when the sub is pumping out those that low range its runing 40-20?40 is lower than 120 hertz (Hz). A hertz is a wave measurement in cycles per second. The fewer there are the lower the frequency is...

So if i set the crossover at 80 then that means anything below that 80 like 79-20 the sub plays?Sort of... 80 is the point where the sub starts and the lows to the mains begin to roll off. The x-over point is not a wall, it's the beginning of a slope. Again the intent is seamless blending.

Oh the sub has a bypass switch so i can turn off the subs internal filter if i need to called "subwoofer direct/internal X-over".. So if i stick with the sub woofer cable i should use that switched to "Direct"since the reciever will be forced with using its internal 80hz filter... Yes

oh wait it might only use that filter when i enable THX mode on the reciever... hmmm.. Is there anyway to verify what the recievers filter is set at besides calling Kenwood? Sorry, I don't know your AVR. Someone elde may, but calling the manf is never a bad idea.

I'd like to try wiring the speakers straight to the sub using speaker wire and bypassing the recievers filters but if i do i'd have to turn off the sub woofer on the reciever... The prob i see with that is i dont see how any low bass from the center and rear channels being played from the sub only the fronts. In order to fix that wouldn't i need another sub for the rear channel and hook them up straight to the rears like the fronts?

No... There's ususally less bass info in surrounds, but that's not the key. The key is that true, low bass is non-directional, i.e., it is difficult to locate the source. Your AVR's 80 Hz poiunt is comfortably in this zone (some say as high as 110 Hz is OK). So routing the bass info from all speakers to the sub is acceptable.

No your question about the rears if you wire the Polk way...

With sub set to "No", the LFE should be routed to your mains, and will be intercepted by your sub. THe LFE gathers effects from all channels so it will support that helo flying at you from behind...

Sub in the corner is a good place to start, but it won't always end up being the best place to stay.

I'm not the one to answer this.

Denon has a good following here. Onkypo as well. HK is gathering a following...