How to Build a Home Cinema Subwoofer Cabinet
Get some free software to figure out the box size., Type a speaker's details into the software., See if the software recommends a vented design or not., Figure out how big a box you will be happy with., Use the software to show you how the speaker...
Step-by-Step Guide
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Step 1: Get some free software to figure out the box size.
These funny numbers are T & S parameters named after some Aussie engineers.
Sensitivity of a speaker is a measure of efficiency.
Try and find one that is rated at more than 90 dB/watt at one metre and can take about 100 watts RMS of power.
Parts express, Jaycar, and eBay are all good for various sub parts.
Car subwoofer speakers WILL WORK FINE, as long as the overall ohm impedance is not lower than the receiver's. , Try a few speakers until you find one that is suitable.
Good ones are vented for efficiency and offer low low bass.
This project has no vent ] but is still a solid performer.
However, by cutting a round hole in it of the right diameter with the right length tube it would really take off down low. , This may involve consulting your life partner. 130 liters (34.3Â USÂ gal) is pretty serious for a 12 or 15 inch speaker 100 liter (26.4Â USÂ gal) for a 10 inch.
To calculate the volume you will be using the inside dimensions in cm (that way you will get the volume in milliliters) minus any bracing, amplifier, the back of the speaker and vents.
Errors of 5% should not matter much. , You will then be able to adjust the box's "tuning frequency"
- don't worry about what this value is too much; just look at the graph and see if the vent is a reasonable length and diameter (see warnings). , If it is still above
-3dB at 35 Hz, you have some decent bass.
The tuning frequency should end up somewhere between 20 Hz (wow you have got a decent speaker) and 40 Hz.
All other things being equal, go lower.
Below the tuning frequency speakers are relatively unhappy, so it pays to go low. , (there is no need for any fanciness, just butt the pieces up against each other) Then get your hardware store to cut it.
They will be straighter and squarer and more accurate than you (probably) which will make it easy to assemble. , Screws at least twice as long as your MDF is thick are best.
You will need to drill clearance holes to allow the screw to pass through plus smaller holes in the other pieces to allow the thread to go in.
Go crazy and glue and screw some bits of wood onto the walls of the box to make it stiff.
The box should vibrate as little as possible (the vibrating speaker makes the sound not the box
- concrete anyone?) and be leak proof.
Don't forget these brace bits (cleats) will change your box volume! , 'Plate' amplifiers designed to mount in boxes are easy.
Just remember to make sure that it does not touch the walls of its hole anywhere to avoid damage.
Also remember it is a mains voltage device.
If you spend
1.5 times on the amplifier what you did (or should have) on the speaker you will be OK.
Matching the speaker to the amp watt for watt is good too.
With an efficient speaker 200 watts is very very loud. , Are all your corners sealed? , Use glue.
Do not stuff the box solid, this technique is for sealed, not vented boxes. ,, If you don't have one, most plate amps will create their own subwoofer channel and return the rest to your amplifier or direct to your speakers (see its manual). , If it is a bit quiet and the auto on function does not work right (most plate amps will turn on when there is a signal) and if the plate amp has a stereo input then buy a cable that splits the single channel .1 into two identical wires and connect them to the stereo plate amp inputs. , Or put it in the front corner and try the phase switch in both directions (don't panic if you can't tell any difference). -
Step 2: Type a speaker's details into the software.
-
Step 3: See if the software recommends a vented design or not.
-
Step 4: Figure out how big a box you will be happy with.
-
Step 5: Use the software to show you how the speaker will perform in your maximum sized box.
-
Step 6: Set the box's tuning frequency up
-
Step 7: so that the line representing your speaker stays between 0 dB and -3dB for as long as possible towards the left (lower frequencies and therefore bass.)
-
Step 8: Figure out the sized panels you will need to make a box from particle board or Medium Density Fiber fiberboard (MDF) 18mm thick or more should be fine.
-
Step 9: Glue (use pva wood glue in large quantities) and screw your sub together.
-
Step 10: Cut holes for the speaker
-
Step 11: the vent (make sure the end inside the box will be 1 vent diameter from everything)
-
Step 12: and the amplifier.
-
Step 13: Launch yourself at the box with the PVA glue again
-
Step 14: this time on the inside.
-
Step 15: Attach some plush carpet or proper speaker 'acoustic wool' (resembling the inside of a synthetic doona) to at least two walls of the box.
-
Step 16: Screw in the components and connect the speaker to the amplifier.
-
Step 17: Use a long 'RCA' lead to connect the input on the plate amplifier to the .1 output on your home theatre amplifier.
-
Step 18: Listen for problems.
-
Step 19: Read some kind of home theatre magazine on how to set up a subwoofer in a room.
Detailed Guide
These funny numbers are T & S parameters named after some Aussie engineers.
Sensitivity of a speaker is a measure of efficiency.
Try and find one that is rated at more than 90 dB/watt at one metre and can take about 100 watts RMS of power.
Parts express, Jaycar, and eBay are all good for various sub parts.
Car subwoofer speakers WILL WORK FINE, as long as the overall ohm impedance is not lower than the receiver's. , Try a few speakers until you find one that is suitable.
Good ones are vented for efficiency and offer low low bass.
This project has no vent ] but is still a solid performer.
However, by cutting a round hole in it of the right diameter with the right length tube it would really take off down low. , This may involve consulting your life partner. 130 liters (34.3Â USÂ gal) is pretty serious for a 12 or 15 inch speaker 100 liter (26.4Â USÂ gal) for a 10 inch.
To calculate the volume you will be using the inside dimensions in cm (that way you will get the volume in milliliters) minus any bracing, amplifier, the back of the speaker and vents.
Errors of 5% should not matter much. , You will then be able to adjust the box's "tuning frequency"
- don't worry about what this value is too much; just look at the graph and see if the vent is a reasonable length and diameter (see warnings). , If it is still above
-3dB at 35 Hz, you have some decent bass.
The tuning frequency should end up somewhere between 20 Hz (wow you have got a decent speaker) and 40 Hz.
All other things being equal, go lower.
Below the tuning frequency speakers are relatively unhappy, so it pays to go low. , (there is no need for any fanciness, just butt the pieces up against each other) Then get your hardware store to cut it.
They will be straighter and squarer and more accurate than you (probably) which will make it easy to assemble. , Screws at least twice as long as your MDF is thick are best.
You will need to drill clearance holes to allow the screw to pass through plus smaller holes in the other pieces to allow the thread to go in.
Go crazy and glue and screw some bits of wood onto the walls of the box to make it stiff.
The box should vibrate as little as possible (the vibrating speaker makes the sound not the box
- concrete anyone?) and be leak proof.
Don't forget these brace bits (cleats) will change your box volume! , 'Plate' amplifiers designed to mount in boxes are easy.
Just remember to make sure that it does not touch the walls of its hole anywhere to avoid damage.
Also remember it is a mains voltage device.
If you spend
1.5 times on the amplifier what you did (or should have) on the speaker you will be OK.
Matching the speaker to the amp watt for watt is good too.
With an efficient speaker 200 watts is very very loud. , Are all your corners sealed? , Use glue.
Do not stuff the box solid, this technique is for sealed, not vented boxes. ,, If you don't have one, most plate amps will create their own subwoofer channel and return the rest to your amplifier or direct to your speakers (see its manual). , If it is a bit quiet and the auto on function does not work right (most plate amps will turn on when there is a signal) and if the plate amp has a stereo input then buy a cable that splits the single channel .1 into two identical wires and connect them to the stereo plate amp inputs. , Or put it in the front corner and try the phase switch in both directions (don't panic if you can't tell any difference).
About the Author
Christina West
Experienced content creator specializing in hobbies guides and tutorials.
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