I’m just listening the Sonic Gear Apocalypx A6, a mini bookshelf stereo speaker with one tube as buffer/pre-amp. I can’t see the tube inside, but I suspect the tube is 6N1P or similiar. I can’t get the tube information either from the box or the website. It’s not important anyway.

I experience problem with port noise from the bookshelf, especially in the vocal region like Ingram Washington (on some song, the low overlap the mid-low region, so you can’t hear the vocal clearly). This is quite annoying for me. Just like hearing an echo around. Perhaps, this is due to my placement (around 30 cm from glass wall).

Quite hard to explain this “port noise”, but simply to say, a port noise is when your port starts to produce sound. The port is the way for the air to flow. So, it should sounds nothing. If it produces any noticeable sound, then we can call it as noise. This noise may be mixed up with the sound from the driver itself and produce unwanted combination (less defined staging, reduce the vocal clarity/definition, etc).

So what should I do then? 😉

I took thing like on the photo above. I think you should be familiar with that thing. It’s a foam. When you buy a motherboard or VGA, you should see it inside the box. Cut the foam to the size around 20×10 centimeter. You can experiment with smaller size to.

Roll the foam and plug it to the bookshelf’s port like photo below.

Now you can have a cleaner vocal and less port distortion 😉

This is actually not the “right” way to fix the problem of the speaker (the right way is perhaps to give your speaker more distance to the wall, 1 meter or so or reduce the bass by using the equalizer). I mean, by doing this tuning, you simply will change the box construction from ported to sealed box. This will raise your bass response (the bass won’t be as low as before) – but the advantage is you will have less port noise and cleaner mid region.

So, only plug the foam when you are experiencing unwanted noise/echo when playing certain music (especially with basso/baritone male vocal, like Don Williams or Ingram Washington). When you want an extra bass, feel free to remove the foam.

You can also experiment with smaller foam and get the best combination for cleaner vocal and bass extension.