Adding a second sub?

[whovous]

I finally have a dedicated room for my 7.1 HT and I am amazed at how much better it sounds. I have three VM20s across the front, R50s on the sides and R15s for the rears, all driven by a Yamaha V661 receiver. I also have a MicroPro 3000 subwoofer. Now that I finally have a system that sounds good, I am looking for ways to make it sound better.

The V661 is a 7.1 receiver. Is there any easy way to add a second sub to this system? Will doing so cost me my YPAO functionality? The 3000s have their own set-up mike and routine, so I suppose I could just leave the sub turned off while setting up YPAO, or is that going to give me a different set of problems when YPAO tries to squeeze more bass out of the VM20s because it does not detect a sub?

Thanks!

[Phasewolf]

When I added a second sub it took a wile too setup the phasing and what not. I used a spl meter too setup the subs but the software in the avr is really limited too what it will let you do with 2. I would put them both on the same wall too start so they are equal distance from where your sitting and get there power level and phasing correct. That way when you set the distance in the avr it will be the correct delay and one will not be off from the other.

[Phasewolf]

I would love too setup 4 15" subs but I think my wife and the people who live close by would burn my alive so I will stick too two subs for now sense I work afternoon shift and no one likes it when I crank things up a 3am

[whovous]

OK, but what do I need for the basic setup? My AVR has only one sub pre-amp output. Is there a simple splitter I should use?

[deronb1]

I used a "Y" splitter for my two subs out of the "sub out" output. It worked fine. One note, put both subs either on 0 degrees or 180. Keep them the same.

[dkg999]

As mentioned above use a Y splitter on you sub-out. Outlaw Audio makes a very nice one. The way I dial in my two subs is to dial-in the system using one sub, either manually or via the auto-setup on the AVR. The start be setting the second sub exactly the same as far as the settings on the sub itself. Work from there with the settings on the sub itself until it sounds good. The second subs location in the room may really impact how much gain you want and the cut-off level. If needed you can tweak the AVR setup, however I've found that's rarely necessary.

[whovous]

Thanks everyone for the advice. Dialing in with one and then adding the second makes a lot of sense to me. If I do this I really want to keep the YPAO capability. In the past I have not been so impressed with it, but in this new room with all of the speakers in pretty much the 'right' locations, I am blown away by the quality of the surround sound. I am also considering adding an amp for the front channels, but I suppose that is a matter for another post on another day.

[Tour2ma]

Dialing in twin subs can be very difficult. It is not an auto-calibration exercise. AVR test tones simply do not cover enough of the <120 Hz spectrum to be utilized. Deep bass sweeps are available on the internet; download, burn, spin... SPL meter read, add correction factors as necessary, plot and cuss... move a sub and repeat as necessary...

The dial in one and add the second approach sounds simple enough, but the odds are that #2 is going to work against #1 (and the room) at one or more frequencies. You may find yourself moving #2 around the room for hours before you finally realize that it is never going to work with #1 because #1 is in a bad spot... not bad for solo duty, but bad for accepting a second sub.

The only way to insure twin subs work together rather than against each other is to literally stack them. If you are happy with the way your sub blends within your room, but just want more, I suggest you start with the stack as a reference for any other arrangements you try. As soon as you add sub #2 to the stack, know that your deep bass/ LFE reproduction is now 3 dB greater and thus no longer in the same "balance" with your 7 ch's. May or may not be an issue as many folk enjoy their subs a bit "hot". If you were already running #1 hot, then you will likely want to dial it back some when #2 joins the party.

[whovous]

OK, let me think about doing it the hard way. What do I need in the way of an SPL meter? Radio Shack seems to have stopped selling them.

[Sherardp]

OK, let me think about doing it the hard way. What do I need in the way of an SPL meter? Radio Shack seems to have stopped selling them.

http://www.amazon.com/Velleman-Analo...949089&sr=8-13

[whovous]

Ordered. I can never resist a cheap new toy.

[Tour2ma]

Excellent...

Sherardp,
That Velleman looks a great deal like the old Rat Shack analog. Do you know if it is?

...

When I Googled looking for an answer to my question up popped this calibration thread at blu-ray.com...
http://forum.blu-ray.com/receivers/3...spl-meter.html

Just skimmed it, but it looks to be a pretty authoritative summary... even addresses twin subs...