Making a car subwoofer


Created on 01.22.2012 15:26.

Updated on 04.02.2020 21:16.

Author: Marat Musin.

Like many music lovers, I had a desire to install a subwoofer in the car. The previously made subwoofer suited everyone, but not with its dimensions – it took up almost a quarter of Oda’s already small trunk. So I decided to build a Stealth building. In addition, there was experience in working with fiberglass.


The main material was purchased – T-13 fiberglass and epoxy glue.

This is how the left trunk niche looks like, in which it is planned to glue the subwoofer case.

In order to prevent the fiberglass from sticking either to the carpet or to the plastic panels of the trunk, and at the same time easily detach from the surface of the trunk, we use a separating layer of two types of adhesive tape – painting and packaging.


The body is glued with narrow strips of fiberglass impregnated with epoxy glue. Impregnation is best done on a sheet of glass. Dilute the adhesive in proportions 10: 1 (10 parts resin to 1 part hardener). As containers for diluting the glue, cups made of sour cream, yogurt, various lids from household chemicals, and so on were used.

Day 2. To save time and material, as well as because of the inconvenience of work, a part of the body behind the suspension post is made of pieces of fiberboard, tied together with a wire (temporarily).

After 2 days of work for 4-5 hours, the following result was obtained, for which 3 packs of epoxy glue, 280 g each were used. and about 2-3 sq.m. fiberglass T-13.

Day 3 and 4. I pasted the upper part of the case, removed some of the wire, glued the joints of the pieces of fiberboard. The right side adjacent to the seat was also made of fiberboard, since the surface is flat. When I finished working in complete darkness, I had to use a table lamp.

Day 5. I glued the left side, along the way increasing the thickness of the lower part of the case. I emptied two more packs of glue.

Day 6. He took the glued-out case out of the niche. The separation passed with ease, nothing extra was broken off. Also on this day, I glued that part of the body, which is formed by pieces of fiberboard. Used up another pack of glue.

Day 7. Conducted approximate measurements of the volume. Measurements were carried out with water, pouring to the brim, more precisely to the edge of the upper part of the case. It turned out 20 liters. At the same time, the water did not even close the protruding half-cylinder. Therefore, we can expect the final volume of 30 liters or more. I see the Hertz DS250 dynamic head as a candidate for the role of a subwoofer. According to the recommendations of the Avtozvuk magazine, he needs a closed box of 23-28 liters.

Day 8. Trimmed the jagged edges of the fiberglass shell. Cut out the front panel of the subwoofer from fiberboard. The lower part of the front panel was secured with pieces of wire. The front part is planned to be curved above the middle of the speaker hole.

In order to prevent the lower part of the front panel from bending, he put another piece of fiberboard to the middle of the hole and made supports from pieces of chipboard / wood.

This is what the curved front panel of the subwoofer cabinet looks like. The upper part was also secured with wire.

We collect the necessary strength and thickness of the front panel with fiberglass.

Day 9. To mount the speaker, I made a support ring of 3 layers of chipboard, which is fixed on the front panel with glue and self-tapping screws.

To strengthen and to eliminate gaps between the ring and the front panel, glued in several layers of fiberglass.

Day 10. I measured the volume of the case – it turned out to be about 27 liters. I ordered a Hertz DS-250 speaker, I’m waiting for it to arrive. For fitting I put Seas H1209 (this speaker is waiting for its fate – to be in a home subwoofer).

My ordered subwoofer Hertz DS250 arrived. The project continues.

The final stage in the manufacture of the subwoofer was pasting with a Carpet. The entire building took about 1 rm. carpet and 3 tubes of Moment glue.

A hole was cut in the end of the subwoofer’s case, adjacent to the seat, in which an acoustic screw terminal was installed for quick connection / disconnection if necessary.

With a stealth subwoofer, the boot volume is significantly freed up.