How to integrate phase of a subwoofer with mains?

A product that I use and frequently recommend is the Velodyne SMS-1 sub controller. Attach a monitor and you will see the effect of any change to any parameter (including phase) on the frequency response at your listening position. I find it tremendously helpful in setting up/integrating subs. It also allows PEq to smooth the subs response - which may well provide dramatic improvement in your system's bottom end. That has been my experience, anyway.

Cost is $450 from Audioadvisor.com.

Good Luck

Marty

If you are interested in the Velodyne SMS-1, you might want to take a look at this link.

http://www.hometheatershack.com/forums/bfd-electronic-equalization-devices/6346-behringer-fbq2496-velodyne-sms-1-distortion.html

It is a couple of years old and maybe that problem has been fixed in the recent versions; but if you are looking to buy used, you might want to double check.

Thank you BRF and Kal, your answers make sense to me. And best of all I won't need to buy any additional testing equipment :)

Sidssp,

Am I reading these right?

The SMS-1 input can be overloaded into distortion. To prevent this, adjust the output level of the source appropriately. Done. No issue (at the preferred -6db input level, distortion for both the Behringer and the SMS is inaudibly low - per those graphs). Granted, the Behringer measures a bit better, but - given these very low THD levels at these very low frequencies - I really believe that you're looking at hairs on the arms of the angels on the head of the pin.

The LF roll off shown for the SMS-1 is down app 2db @20hz. I filter at 25hz anyway for my music only system. This might be an issue for HT use, but not IMO for music.

Unless those results are viewed in light of HT use, they will be awfully misleading. Unless I'm missing something -and it wouldn't be the first time for that!

Marty

A bit off-topic and this may not contribute to the thread.

I find that most musical material differ in bass frequency output. Some albums will have more bass and sound boomy even without the subwoofer integrated into the system(room acoustics affect this to a certain extent) while some albums will need the volume/crossover on the sub to be turned up considerably high above the half-way point on the volume knob of the sub in order to feel the bass. As such, I am unsure whether setting-up the sub accurately using test tones as suggested by most folks(which is supposed to be the correct method anyway) will apply to all conditions and all albums, both CD and LP format.

I don't know about others but the settings on my subwoofer are always changed periodically dictated by the particular CD or record that is played. Any insight on the proper method to professionally set up the subwoofer would be appreciated. For those who have professionally set up the sub using test tones, do the settings stay put for all listening material?

p/s: I have a Radio Shack meter and test tone CD.