Designer:
HILO

Project Category:
Subwoofers

Project Level:
Advanced

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
Very compact (0.64cu ft.), flat frequency response and clean sound subwoofer design was successfully completed with 4th order band pass enclosure. The characteristic of band pass frequency response and DVC (Dual Voice Coil) Driver enables just add and parallel connection with current poor-bass stereo such as PC speaker systems. Dayton Audio LS10-44 10” unit fits for my compact enclosure design.

Design Goals:
I had an idea to built 2.1 channel desktop speaker system and sub woofer system for my car. I hate to hear the harmonics of subwoofer’s distorted sounds. So I decided to build band pass enclosure for this purpose. In car use requires some loudness to win the road noises. Deep bass and over 100dB maximum SPL with small enclosure is a final target of my project.

Driver Selection:
Choosing a unit which has a following features…
– Not so much expensive
– Durable
– Small basket space
– Over 10mm Excursion
– Can produce over 100dB SPL.
I simulated various units with “Basta!” software. Finally I decided to use Dayton Audio LS10-44 for this project.

Enclosure Design:
This encloser is my 3rd band pass box project. I used design software, which named “Basta!” by Tolvan Data. I put the parameters and submit the specs to cover the frequency range from 38Hz to 100+ Hz with allowing some ripples (within 3dB). Cut and try with small box volume design was reached to reasonable size for my placement space.
To built with small footprint, I tilt the unit inside of enclose.

Enclosure Assembly:
The most important thing of 4th band pass enclosure building is a perfect sealing and strong construction of front (vent) side. I used only 12mm thickness plywood, but I laminated FRP (Fiberglass Reinforced Plastic) inside of enclosure. As a result of this, total weight of this speaker system is only 9.4kg. (Includes LS10-44 weight 4.9kg) Dimensions are 11.8” x 11” x 12.5”. Flared Port is 56mm inside diameter with 260mm length PVC pipe.

Crossover Design:
Band pass enclosure has Hi-Cut features by itself. But there are port resonant peak will produced in mid-high frequency range. So I used with active channel divider for my 2.1 channel speaker system.

Tips & Tricks:
PVC pipe ends are flared to reduce the wind noise. The way to this modify end. Bake PVC pipe end and rotating it put on the bottleneck. This is easiest way to do this modification.

Conclusion:
The output sound is clear and pure fundamental of bass without harmonics. Even if the amplifier was clipped. Maybe most of users are hard to identify the presence of subwoofers. This characteristic will fits for 2.1chanell speaker system. Simply parallel connection to existing audio system will be an easiest way to challenge use of this subwoofer.

About the Designer:
I have been interested in DIY Car and Home Audio over 20 years. My hobby project activities are stated in my homepage. You can search and visit my homepage which named “CyberPit HILO”. (Sorry, most of my pages are in Japanese)

Project Parts List: