Sub Woofer and Mains (1 Viewer)

[Doug MacGregor]

I read somewhere here in the last couple of days (can't find it now), where one of your members suggested setting my Mains to Small regardless of their size to get the most out of my Sub, due to the fact that "most Mains are not full-range"
Here is my setup...
I am new to HT so bear with me.

JVC RX6010VBK Receiver
JVC XVS500BK DVD player
Mission M70AS 8" Ported Sub
DIY Mains with Philips drivers (1" cone tweeter, 2" cone Mid, and 10" woofer)
Quest Centre Speaker (Q50c)
Audio Research rears.

I have everything set to "Small" except for the Mains so I assume they are using the standard crossover frequency (whatever that is).
The Sub has a crossover adjustment knob that allows me to adjust from 75-150Hz and I have it set just shy of the half-way mark (probably about 100Hz).
Everything sounds good to these 50 year-old ears, especially the Balrog scene of LOTR.
The living room is large (24X14) with a vaulted ceiling.
Is there an advantage to setting my Mains to small with a crossover of 80Hz?
I thought that the 10" woofers in the Mains could handle pretty low frequencies or, maybe that's not the point.
Can anyone enlighten me on this point?
Thanks in advance.

Doug

 

[Scott Cunninghm]

Great question, I am waiting on the answer as well as I just ordered my first subwoofer.

Right now all my speakers are set for large. I will try them on small once the sub arrives.

Hell, I don't even know what the crossover adjustment or other options are supposed to accomplish on the sub. This will be an interesting thread to watch.

 

[Brian Fellmeth]

The Sub has a crossover adjustment knob that allows me to adjust from 75-150Hz and I have it set just shy of the half-way mark (probably about 100Hz).

No. turn it as high as it will go or better yet defeat it entirely with a switch or an alternative jack (if the sub has these options). The sub crossover is there in case you had to feed it a full range signal. Your HT receiver has already prepared the signal for the sub, and the sub amp should do no further filtering.

 

[Doug MacGregor]

OK.
Thanks Brian.
I guess where I was uncertain was in the nature of how the receiver was handling the signals sent to the Mains.
Reading between the lines of the manual after reading your reply tells me that setting speakers, any of the speakers, to "large" means "send everything to me" and setting them to "small" triggers the internal receiver crossover, which is changeable from 80 > 100 > 120.
I guess I was also confused between "driver specific" crossovers - as in the case of the internal crossover in the Mains - and "system specific" crossovers as handled by the receiver.
This HT stuff is a lot to take in - not like the old days with straight stereo - but with help like this, it's starting to become clearer.
I will also set the Sub crossover to 150Hz.
Appreciate the response Brian.
This is a terrific forum.
Cheers.

 

[Jack*Mains]

Here is my question:

I will be purchasing a receiver soon, and I just dont see why they make it impossible to have the mains receive a full range signal, plus send the low signal from the mains *and every other channel) to the sub. It just seems to me that it would produce a 'fuller' sound.

Unless I missed something, and it IS possible to do what I described, then I should be looking for a receiver that has specificly that feature.

 

[Ryan Schnacke]

Jack,

Some receivers will allow you to do this. I think Yamaha, may be one of them. But the question is WHY would you want to do that? You'd be getting a double portion of the main channel bass. Or rather, you'd be getting a double portion of the main channel bass that your mains can reproduce. If we ignore the possible complications of cancellations between the mains and the sub we still have to deal with the issue of proper calibration.

Let's say you watch a movie with the majority of bass in the main tracks. You get the double portion and you're very satisfied with the performance. Then you watch a movie with the majority of bass in the LFE track. Suddenly your bass is 6dB weaker than what you're used to since you're not getting the double portion of bass in this track. Everybody else is raving about how this movie "cracks the drywall" but you're left with a ho-hum performance. You could turn up the subwoofer level but then the first movie's bass would be overcooked.

Play the signals as they were meant to be played. Then if you want a "fuller" sound just run the subwoofer level a little hot. This way every movie is equally a little hot in the bass performance.