Bass Tube DIY

For a long time I have been very interested in building speakers… for home, for stage, for car and for outdoors… I have tried many different styles and types of enclosures… but I came home from work and looking around in my garage I decided to build a very quick bass tube out of free junk I have collected. I have always wanted to try this type of tube style (Bazooka tube) with the extra added horn/port… and I figured I would capture some photos along the way to show the build.

Next I gathered my supplies which had all been collected from recycling bins, asking for free stuff from other peoples projects, etc.

I went on line and found a very small and efficient sub woofer to use in the bass tube. So you will have to determine your woofer and how much you want to spend. Maybe you can obtain one from a used speaker, buy a used one from an on-line auction. But once you find out what make/model it is you need to obtain the specifications of that speaker... it is critical to determine a few things about the woofer in order to design the tube length and size the port just right.

Here is a list of items I got for free:

Plastic tube approximately 8 inches in diameter (used to roll carpet, or other fabric material from the manufacture).

A same size (length and Diameter) cardboard tube, these two items will become the body.

I got some scrap particle board large enough to cover both ends of the plastic tube.

Some blanket matting I had from a different project I worked on. This will become the interior tube baffle or damping material.

12 AWG speaker wire. This must be a foot longer than the tube as it will be run the length to ensure I have good connections to the speaker and the quick connector on the end plate.

A yard of speaker box fabric.

Here is a list of the tools I used:

1. Hot glue gun
2. Razor blade
3. jig saw
4. soldering iron
5. drill
6. drill bits

Here is the list of items I purchased to finish the project:

Building caulk, quick connector, glue stick, pyle subwoofer (Pyle Power PLPW6D Woofer - 300 W RMS - 1 Pack) and screws to mount the speaker and the quick connector.

Plastic tube is cut to the correct length which is based on the volume needed for a ported enclosure.. in my case it was 27 inches.

Using one of the on-line calculators I entered a few of my speaker parameters from the data sheet and you soon get all the dimensions for the tube cabinet.

I used a very small amount of hot glue to get the batting to stay in place along the inside of the plastic tube.

I just used some construction adhesive to join everything… since it is ported I am thinking the pressure will be minimal and not fatigue all of the parts connection points. I might run a few drywall screws in key locations just to be safe before I cover the tube. These key locations are the places where the cardboard contacts the particle board ends.

Seal all places that the cardboard tube touches the plastic tube. As for the plastic tube you must cut out a port hole to allow the air to pass from the main cylinder into the port half cylinder. I did exactly half of the cardboard tube as the side port, added 3/4 of an inch for the length to allow an over lap on the particle board end.

With some scrap speaker box carpet, a hot glue gun and the sub woofer begins to take it's final form. I mounted the speaker after soldering in the speaker wires to the lugs. I recommend soldering as the bass tube will vibrate any other type of connection right off....and there you have it..a finished bass tube. Approximate hours it took me to build is an estimate of about 4 hours all together.

The Boss amplifier was a deal at $55.00 on sale on-line… free delivery, and at more that 75% off I thought I would take a chance. I was skeptical about the rated 1500 watts Peak into a two Ohm load, but after hooking it up in the basement and running it for a while I was very pleased with the clean sound and more than enough power. The amp also met many requirements: must have active variable crossover, RCA OR Speaker level inputs, soft start turn on and stable at 2 Ohm… (Nothing like the amps I used to have back in my highschool days!) so for the 55 dollars I felt like I got a very good deal for a good subwoofer amplifier.

Future posts I will try and test using a frequency sweep from the 20Hz range up to the 75Hz range. Taking a sample at 5 Hz increments and plotting the speaker output for a comparison and a detailed analysis of the ported tube enclosure of “My Design”.

Thanks for checking out my post. have fun and be safe... power tools, hot glue guns, razors and drills are your friend when used in the correct and safe way!

WilliamD44