Port noise on VTF-3 with max. extension

[akhaksho]

I've had a VTF-3 for a couple of months now and I really like it. One thing I've noticed is that there can be a lot of port noise when I have the sub set to max extension mode. Is this normal? If I play the Saint Saens Organ Symphony from the test CD, I get a fluttering or chuffing sound several times. It makes the same noise regardless of how far the port is from the wall. I've never heard it with anything else other than a test tone and am just wondering if the sub has some kind of problem.

[Michael Bain]

Maximum extension mode on the VTF-3 is intended more for deep bass music listening (which is generally not done at ultra high output levels), with a slightly more extended response over maximum output mode. Maximum output mode on VTF-3 is usually the preferred mode, especially if you want to play loud bass (in part because of the extra port area and higher tune). It provides more output (about 3db more from 25 to 40Hz approximately), while maximum extension mode provides slightly lower frequency response.

[cschang]

Also make sure the proper port is plugged.

If you look at the ports, inside one of them you can see a cardboard looking tube attached. This is the one that should be used with the port plug.

[Sasha_G]

That demo disk is a killer test of any subwoofer, because it is almost all very deep bass (mostly infra-sonic) with very little music at higher frequencies. It is a rare track where the bass is meant to dominate the music, and it is almost entirely below the range of hearing. So, any faults in a subwoofer such as port noise or suspension noise can be heard, since there is no music to drown it out. Throw that track at most subwoofers, you will not hear anything at all at best, and at worse you will hear the suspension and ports struggling.

There is a little port noise when playing the VTF-3 very loud in max extension mode. Fortunately, its effects can be reduced. If you read the manual, it will explain that there is some port noise in that mode but it can be reduced by placing some eggcrate or acoustical foam a few inches behind the subwoofer.

[airs]

I also am noticing this port noise on my VTF-3 MKII. I looked in both ports and didn't see the cardboard that craigsub mentioned... :(

[Pete_Hsu]

Dear airs,

Are you running the subwoofer in amplifier maximum extension mode with one port inserted?

If you have not done so already, feel free to send your system information to Dr. Hsu via the service tab on this website, and he will give you some setup recommendations.

When the turbocharger is ready, then port noise will largely be a non-issue.

Sincerely,