Set up basics

[YK Thom]

In the process of setting up the system in a new place with a larger room than the former. My new AV unit is wider than the old one so the front mains will need to be farther apart. Have heard many recommend the equilateral triange route. I think I may be able to almost accomplish this. The speakers ideally (if the right is to remain on a stand) will need to be 11 feet apart. The centre point on the chesterfield will be about 10 feet back. There is room for play as we have several feet free behind the couch and back wall intended as a clear walkway to access the balconey. My rears for the first time will be behind the listening area rather than beside.

Before I start cutting cable, will RB61IIs perform with this much separation? At the old place they were only eight feet apart.

[moray james]

no problem, an equilateral triangle is my starting point for loudspeaker set up. sounds like this will be a very nice set up for you.

[Quiet_Hollow]

Before I start cutting cable, will RB61IIs perform with this much separation?

How good is your sub?

 

Meaning, the further separation of the RB61II reduces their combined low frequency output, requiring more output from the sub to fill the hole in the upper bass region of the pass band. Not all subwoofers perform well in that regard.Hence the 'ol "sealed vs. ported" debate.

 

The RB61II won't be the limiting factor in your new arrangment.....for now.

Edited September 27, 2015 by Quiet_Hollow

[YK Thom]

The sub is a fairly modest KW100 (down firing and rear ported). Up until now it has served me well. The room is not huge and I don't go for thundering wall/floor shaking bass-I'm in a high rise condo after all. I like to noodle around and get it to the point that my stand mounts sound like floor standers.

The RB61IIs spec out from 45HZ to 24 KHZ.

Edited September 27, 2015 by YK Thom

[Quiet_Hollow]

Thunderous bass isn't my point either. It's all about integration, not sheer output..right?  ....and I'm also not implying that the current sub is not up to the task...just that some experimentation is going to be involved...possibly even a new part.

 

Careful with the RB spec, that's not reality. In practice, bookshelves sign off a lot higher than their literature suggests...espcially on stands.

 

With the speakers spread out, you're going to have to raise your low-pass filter (the crossover) respectively.....that requires output from the sub in a sonic region where not all subwoofer designs are particualrly happy.

 

Just saying, the new layout is not a problem for the RB's, but rather it's gonna depend on tweaking the filters and the sub to get it sounding just right....possibly even a different sub in order to round it all out. 

 

Sounds weird talking about the sub when moving the mains around, but that's acoustics.

[YK Thom]

I hope I can make it work as I'm pretty tapped out from the move. I understand what you are saying. A new sub right now would involve a lawyer and couch surfing...

[derrickdj1]

Try the sub near one of the mains or as close to 1/2 between the mains.  If that does not work, the rear of the room.  As Tom said, experiment.

[YK Thom]

I'll try that. I have a bit of wiggle room with location and WAF. I will also seriously look into Quiet's idea. Where would you suggest I should try setting my sub crossover at?

[derrickdj1]

Try 80 Hz, you may be able to go a tab lower.  Also try 100 Hz and see what sounds best.  If the sub is near the mains, you can get away with a higher XO like 100 Hz.

[Quiet_Hollow]

Due to a combination of the subwoofer interacting with a typically sized room and the way a low pass filter shelves (EQs) the native frequency response of the subwoofer, crossover (as defined acoustically) occurs at a frequency higher than the low-pass filter (aka. the knob on the subwoofer) and at or little bit lower than the main channel high pass filter (the set point in the AVR)

 

So in practice, when you set the knob on the subwoofer to a specific frequency, things are actually taking place a little higher up than you'd be inclined to think. Hence, the majority of people (that employ direct radiating designs) that typically report "good sound" while setting to somewhere's between 40-60 Hz at their subwoofer.

 

Likewise, when you set the value in the receiver, the main speakers will either very likely cutoff right at that point chosen or be in the process of rolling off a little before that. Hence, most people end up leaving that set to around 80-90 Hz.

 

All combined, yielding an acoustic crossover somewhere's between 80-100 Hz.

 

This is readily observable using RTA, if you've got access to it.

 

But in this case, with such small speakers spread that wide and on stands, they'll require pushing that (acoustic crossover) upwards near the 100-120 Hz mark. Setting 80Hz and something like 110-120Hz respectively. That's a much more sensitive range to make adjustments in, comparatively speaking. Lot's of music power in that octave and plenty of room interaction still taking place between all three elements. All in addition to the traits inherent to a vented/ported sub. The system will be very touchy. You'll be able to very clearly hear bass line drop outs, if not feel them, dependent upon whether you've got it setup right or not.

 

I totally agree with Derrick's advice, somewhere along the front wall is going to be your safest bet with the KW100. That or secondly the back wall, because sitting right on top of a vented/ported sub is not a practical option.

 

Keep the filter set points spread apart. Avoid stacking'em right on top of one another. Afford plenty of time to tweak because without RTA, could easily take a month or two to sort things out.

Edited September 28, 2015 by Quiet_Hollow