As true connoisseurs of quality sound, many people are trying to improve their audio media. The most effective improvement is the high power woofers. These speakers are called subwoofers. If you do not have the opportunity to purchase a subwoofer, but you have all the materials and tools in order to assemble it yourself, the instructions below will help you.
It is necessary
- - hacksaw for working with wood
- - files (triangular, flat, round)
- - chisel
- - electric drill
- - screwdriver or screwdriver
- - jigsaw
- - stationery (pen, pencil and ruler)
- - compasses with a wide step
- - sealant, PVA glue, wood glue.
- - plywood with a thickness of 1 to 2 cm, wooden blocks of 20x20, 30x30, 40x40.
- - self-tapping screws from 1 to 5 cm
Instructions
Step 1
Find the right tools for the job. Install the JBLSpeakerShop program on your computer.
Step 2
Before starting work, be sure to calculate the basic parameters of the speaker. The fact is that there are no exactly the same speakers, even if they are absolutely the same model and rolled off the same assembly line on the same day. The difference between them will be small, but we must take it into account. According to these parameters, in the future you will choose the type of box for the subwoofer. Write down the characteristics obtained on a piece of paper and keep this piece of paper until the end of the work.
Step 3
So, you need to calculate the following characteristics:
Pnom - this parameter means the nominal power of the speaker, it is given in the head brand (75GDN-1 75W).
Fs is the natural resonance frequency of the speaker in open space.
Fc - This parameter means the resonant frequency in an enclosed space.
Qts is the total Q factor at the resonant frequency.
Qes is the electrical Q factor at the resonant frequency.
Qms is the mechanical quality factor at the resonant frequency.
Vas is the abbreviation for equivalent speaker volume.
D is the effective diameter of the diffuser.
Xmax is the maximum displacement of the diffuser.
To measure these parameters, use a calculator, voltmeter, LF generator, sealed box with a volume of about 20 liters.
Connect an amplifier to the line output of the sound card. Connect a speaker from the output of the amplifier through a resistor. The power of the resistor should not be more than 2 W.
Measure all parameters and write them down.
Step 4
When you get the speaker parameters, then move on to choosing a subwoofer box. If your speaker has an Fs higher than 100 Hz, then choose a free radiator (Free air).
If Qts <0, 8 … 1, it is optimal 0, 7
product Fs / Qts = 50
The third version of the box is a vented box. Choose it if Qts <0, 6, optimally 0, 39
product Fs / Qts = 85
The fourth option is a Passive Radiator. It is very, very difficult to do it.
The fifth option is the Band pass. Choose it if Fs / Qts = 105. This option is effective, but also the most difficult to execute.
Step 5
Unzip the JBL Speaker Shop software to the root folder of the disc. Run setup.exe from the DISK1 folder. Run the program: Start => Programs => JBL SpeakerShop => SpeakerShop Enclosure Module.
It is not difficult to work in the program, so we will not describe this work in detail.
Step 6
Using the prepared tools, make the box itself, focusing on the parameters of the speaker. Remember that the more powerful the sound, the thicker the sides of the box should be. Be very careful with the size of the speaker hole, use a pair of compasses to mark it. File and sandpaper all edges. Work carefully so as not to injure yourself or plant splinters.
Step 7
Do not forget to glue the inside of the box with sound-absorbing material.
