Hi Folks

I had couple of newbie sub questions. I am assembling our first HT setup. I have
paired Denon 2807 receiver with Polk RM6900 surround speakers - for a 10 x 12
room.

My question are:

1. does the driver of the sub have to face the soundstage or can it face a piece
of furniture / couch / wall ? From what I have heard, most of the sub sound gets
transmitted through the floor to the listener (not sure where I heard that) - so
maybe it is ok if the driver not open to the listening area ?

2. the polk speaker manual advises to connect all the surround (front and rear)
speakers to the receiver through the sub (instead of directly as one would
normally do). Are there any specific advantages of doing it like this vs. the normal
way where surrounds are connected directly to the speaker ?

3. should i set the crossover freq on the sub or the receiver ?

Appreciate any advice.

-Kuntal

I had couple of newbie sub questions. I am assembling our first HT setup. I have
paired Denon 2807 receiver with Polk RM6900 surround speakers - for a 10 x 12
room.

My question are:

1. does the driver of the sub have to face the soundstage or can it face a piece
of furniture / couch / wall ? From what I have heard, most of the sub sound gets
transmitted through the floor to the listener (not sure where I heard that) - so
maybe it is ok if the driver not open to the listening area ?

If the sub is set to produce sound below 80Hz, the driver position is really not critical. At around this point is where the sound becomes non directional. The physical location of the sub is more critical since sound waves interact with your room. Read the Polk manual carefully and follow their suggestion.


2. the polk speaker manual advises to connect all the surround (front and rear)
speakers to the receiver through the sub (instead of directly as one would
normally do). Are there any specific advantages of doing it like this vs. the normal
way where surrounds are connected directly to the speaker ?

Are you sure that they want you to connect all speakers to the sub? Most sub can only take a pair of speakers. Read the manual again to make sure.


3. should i set the crossover freq on the sub or the receiver ?

If the sub is connected to the receiver using the subwoofer/LFE out jack, then use the receiver crossover. If the sub is connected using the speaker wire from L/R speakers on your receiver, set the front speakers to large and adjust the crossover on the sub itself.

thanks for the reply. on #2, u r right - it says to do that only for the front pair.

tho the ques remains - any specific adv to do it that way ?

If you have a Denon 2807, it has enough adjustability you can use the "sub out" jack to hook up the sub. Connect the "sub out" jack to the yellow "LFE" input of the sub. Then connect all the speakers directly to the receiver to their respective speaker outputs. Next, adjust the following settings on the receiver: Speakers = all small, subwoofer = yes, crossover frequency = 120 Hz.

thanks for the reply. on #2, u r right - it says to do that only for the front pair.

tho the ques remains - any specific adv to do it that way ?
No. The speaker connections on a sub are only there for those who do not have the option of connecting via the LFE jack.

Second noob question (sorry for hijacking the thread), should the ports on a sub be a minimum distance away from the wall? Or can the back of the sub be placed right next to the wall. For example, the HSU VFT2 Mk3. Also, are those ports audible? If you are listening to music at a low volume and the sub is close by, will you hear air flowing back and forth?

There will be a lot of air coming out of those ports when you play the right source material. You definitely want to give it room to breath.

It would be good to have at least 3" space for the ports, and 1.5" for the woofer. As to whether you can hear port noise with the sub close to you, it depends on how loud and at what frequency, and how much higher frequencies is going on at the same time. If you worry about port noise, I would suggest getting the VTF-3 MK3 or even better, the MK3 with turbo. With the latter, I hear no port noise up close at full power even without too much higher frequencies playing at the same time.

It would be good to have at least 3" space for the ports, and 1.5" for the woofer. As to whether you can hear port noise with the sub close to you, it depends on how loud and at what frequency, and how much higher frequencies is going on at the same time. If you worry about port noise, I would suggest getting the VTF-3 MK3 or even better, the MK3 with turbo. With the latter, I hear no port noise up close at full power even without too much higher frequencies playing at the same time.

Dr. Hsu,

Thank you for taking the time to visit this forum.

Should there be any concern about the HO or VTF3.3 driver firing into a wall with it's side mount configuration? If I placed one in my current configuration, the driver would fire into an exterior wall, does that make sense?

Thanks

If you have a Denon 2807, it has enough adjustability you can use the "sub out" jack to hook up the sub. Connect the "sub out" jack to the yellow "LFE" input of the sub. Then connect all the speakers directly to the receiver to their respective speaker outputs. Next, adjust the following settings on the receiver: Speakers = all small, subwoofer = yes, crossover frequency = 120 Hz.

Thanks for the info Eric. Coming from "Polk Audio Tech Support", I guess it settles this once and for all :)