SVS PB10-ISD and Denon 3805

PhillyDan1969

I am looking for advice on the best set-up for this reciever/subwoofer combo. Currently I have all the speakers set to small with the subwoofer on and all LFE going strictly to the subwoofer. I believe I set the crossover at 100hz but is it better to go to 80hz.

What phase should I set it at (honestly I am not sure I completely understand this function) and what volume level on the subwoofer do you typically set?

Any help would be greatly appreciated.

Airplay355

what speakers are you using as mains?

set the phase to 0. the phase changes the direction of the driver. with the phase at 180 the driver will move in instead of pushing out.

gregure

While it would be helpful to know what speakers you are using, I will assume you are using speakers that can perform at least down to 80 Hz. I have the Rti 10's for mains, and I still set them to small, and crossover at 80. I tried running them large, but noticed a real lack of bass, due to the SVS's superior bass, and running double bass (full range to mains plus L/R bass to sub) was too boomy. Unless you are using tiny sattelites, 80 Hz is a good place to start (the THX standard by the way).

The phase switch is relatively simple as well. Simply put, the phase changes the wavelengths of the bass in order to minimize spikes and dips due to interaction with other sound waves from your other speakers, and/or the sub's own soundwaves bouncing back from your floor/walls/cieling. This is known as room interaction.

Pick yourself up an AVIA DVD for calibrating sound and picture. It works really well. You'll also want to pick up an SPL meter from radio shack as it will detect any spikes or dips in bass response better than your ears can. That will help you to set the phase the best. If you just want to do it by ear, stand in the middle of the room, or in the main listening position, have someone slowly turn the phase switch to the position in which you hear the best bass performance.

Lastly, the gain (volume) knob on the sub. Again, simply set it to the level that you are comfortable with. I have mine up about 1/2 way and am more than satisfied with the room-shaking output. It is usually recommended to set the sub level (or LFE level-some receivers offer both) down a couple dB's and then compensate with the volume knob on the sub itself. This seems to keep the sub from being overdriven by the receiver.

Just knowing your receiver and sub, it sounds like you have a great system. The 3805 can adequately drive even higher end speakers like Definitive Technology towers. And the sub simply rocks my world. A little boomy at times, but the overall impact is superb, and for the money, no one can come close in extension or sheer power. Good buys!

Hope this all helps. Happy listening.

PhillyDan1969

Originally posted by Airplay355
what speakers are you using as mains?

set the phase to 0. the phase changes the direction of the driver. with the phase at 180 the driver will move in instead of pushing out.

are RTi10s, center is CSi5, and surrounds are RTi6s. I am currently in the market for some FXi3s or FXi5s.

Thanks for the information about phase, I guess I kind of understand that better than I thought since I left it at 0.

PhillyDan1969

Gregure, our systems are very similiar when it comes to speakers. Thanks for the response. I have the Avia DVD and the Digital Video Essentials I just need to go pick up the SPL meter from Rat Shack.

cnjvh

The 3805 has an auto setup feature that will set your phase for you. It does this by setting the distance between all speakers and the listening position individually. The denon will then delay the sound for speakers that are closer to you so all sound waves reach your ears at the same time.

This accomplishes the same thing as tweaking the phase knob on the sub.

Set the sub's phase to 0 and run the 3805's auto set up. If you want, you can then "fine tune" it by using your SPL meter and having someone move the phase knob. I tried that and found that the Denons auto setup had done a fine job.

Also. don't be suprised if the Denon says your sub is farther away than it is. It hears it as such sice the signal is delayed on its way through the sub electronics.

VR3

180 degree phase has *always* been better for me. Never has been an instance that it wasnt flatter/stronger in the lower range than 0.

cnjvh

Originally posted by Vr3MxStyler2k3
180 degree phase has *always* been better for me. Never has been an instance that it wasnt flatter/stronger in the lower range than 0.

Do you find this creates a valley through the crossover? When I go out of phase I get a horrendous valley from around 75-85.

gregure

I have also found that 180 is where I get the best bass performance. I have no "valleys" at the crossover as mentioned above.

VR3

My 'room' has valleys and mountains - not the phase. The 180 degree phase softens those mountains and valleys more than 0 or 90 degree phase does though.

cnjvh

Certainly rooms have peaks and valleys but can they not also be caused by phase cancellation? The only reason I say this is that since the crossover isnt a brick wall (some frequencies below the crossover still go to the mains and some frequencies above the crossover still go to the subs) that those frequencies around the xover present in both the mains and the sub would be nuked by the sub being 180 out from the mains. This seems to be backed up by my measurement sweeps.

Can someone comment on the theory of this? Is it possible that 180 out seems tighter and flatter because the frequencies being elimiated by the phase cancellation are the notoriously boomy ones (70 - 100ish)?

Or do you think you guys just had specific room interactions that were covering the 180 phase cancellation?

Sheesh, sound is sure weird...:D

stringman57

Originally posted by cnjvh
The 3805 has an auto setup feature that will set your phase for you. It does this by setting the distance between all speakers and the listening position individually. The denon will then delay the sound for speakers that are closer to you so all sound waves reach your ears at the same time.

This accomplishes the same thing as tweaking the phase knob on the sub.

Set the sub's phase to 0 and run the 3805's auto set up. If you want, you can then "fine tune" it by using your SPL meter and having someone move the phase knob. I tried that and found that the Denons auto setup had done a fine job.

Also. don't be suprised if the Denon says your sub is farther away than it is. It hears it as such sice the signal is delayed on its way through the sub electronics.

cnjvh, do you happen to know if the auto set up on my Yamaha does the same thing as the 3805 as far as setting up phase settings. I know it measures speaker distances.

cnjvh

I'm not familiar with your model, but if you're certain that it sets speaker distances, then yes it is setting phase. It is timing all of the speakers so all frequencies reach the sweet spot at the same time which eliminates the phase cancellation that occurs when frequencies of identical wavelength reach your ears at different times. The crossover between the sub and mains is the main culprit since this is where most of these duplicate frequencies are found, but all speakers need to be set correctly.

Also, as others have noted in this thread, the room response can make worse or even out phase cancellation due to reflections and such so it can help to "fine tune" your sub's phase with an SPL meter after running the auto setup.

There are many here who understand this better than I so you will find good help here.

Hope this helps :-)