*In process – thanks to all members who have contributed!*
Since I’ve received so much help from the guys on this forum, I figured I would put together a quick FAQ that addresses some common questions that seem to repeat on here pertaining to DIY subwoofer and loudspeaker building. I've also received many PMs which seemed to have a common theme in terms of question content. I will try to address many of them in this post.
In general I'm trying to keep this basic as the amount of information to the new guy is more than overwhelming already. If any of you have useful links that provide additional detail in a specific area that would be helpful, please chime in and I will add it.
General advice - Building your own gear is extremely gratifying and rewarding. With that said, be prepared for some roadblocks, challenges, and mistakes along the way. A warning that this hobby, and especially DIY projects, are EXTREMELY addicting. More is never enough as they say. Take your time, try not to obsess over the details (like I do!), and balance your projects with other important aspects of your life like family and friends. Don't overwhelm yourself by trying to learn every step at once. Take it one step at a time, keeping in mind your goals and limitations. There is always time for another project down the road, time to make corrections, changes, etc. Wood and materials are relatively inexpensive, but the learning you receive from this process is priceless. Enjoy the journey - that is the FUN part!
First off - designing your own build from scratch can be very daunting for a new DIY user. There is nothing wrong with copying and/or personalizing a proven design from others on here.
Master list of subwoofer builds here
Master list of loudspeaker builds here
More speaker builds here
General PI speakers FAQ with tons of useful information for your build in this
Note: I will continue to update this post as I think of other topics to add. Feel free to contribute and I will add to (and correct) this post as needed.
What tools do I need?
Here are some of the typical tools used by a DIYer:
- MANDATORY - Hearing, eye, dust/respirator, and ear protection. This is not optional.
- Some type of saw to do your rip and crosscuts. Options include a table saw, circular saw with a guide/track, panel /vertical saw, etc. Alternatively you can bring your cut sheet to Home Depot, Lowes, etc. and have them do your cuts and you can bring home a rough “flat pack.” Warning: If you chose to have a big box store make your cuts, bring your own measuring and marking tools. These stores have been known to be less than accurate at times. It is also better to have the cuts slightly larger and cleaned up at home than to have them too small and have to recut. A good piece of advice if you're new to cutting: Make any boards that have overlapping edges (front baffle, sides, etc) slightly larger so they can be trimmed after install. A good general recommendation is 1/8" larger. A router can be used with a basic flush trim bit to clean up these edges in merely seconds. That extra "buffer" will ensure your boards do not wind up too short in critical areas.
- A means to make your baffle cuts. This can be a plunge router (I love my Bosch 1617) or a simple jigsaw with a good blade. A router provides the ability to do “rounded edges” as well as other tasks like cleaning up edges and so forth and can be a very versatile tool for the DIYer. For smaller cuts such as under 4” you can likely use a hole saw. A good router discussion is here.
- A miter (chop) saw can be handy if you are making your own grills out of wood pieces, but a circular saw could be used as well.
- An assortment of parallel or bar clamps (or similar) to hold the enclosure(s) while they are being glued. Trust me when I tell you that you can never seem to have enough clamps.
- carpenter's square and pencils
- A drill and good set of drill bits – for mounting the drivers, installing terminal cups, etc
- Sandpaper with a block, orbital sander, or belt sander to prepare the box for finishing.
- A putty knife to spread bondo, wood filler, or your finishing material of choice.
- Finishing equipment : Spray gun, roller and tray, brushes, paint tray. Some types of paints require specific tools to apply.
- GLOVES – these come in very handy during the gluing and painting phases.
Here is a good link providing some popular tools used to perform typical sub/speaker build tasks.
Note: Going with a flatpack like those from www.diysoundgroup.com
greatly reduces the number of tools (and effort) required to the bare essentials like glue, clamps, and finishing materials.
What materials do I need?
General woodworking help
How to use a table saw
How to use a router
Help using a jasper jig to cut circles / baffle cutouts
- Wood for the enclosure and bracing: Popular options include MDF, Baltic Birch, and ‘cabinet grade’ plywood. Baltic birch can vary by local availability, but MDF and other plywood are often available at most big box stores. You are looking for a sheet of wood that is primarily void free, unwarped, and contains solid/straight edges. 3/4" thickness is a very popular size used. Some will use wood dowels as a means of bracing as well. Many chose to use a double (or even triple) baffle configuration to provide extra support and/or visual appeal.
- Screws to mount the driver and terminal cups. Some like to use the hurricane / t-nuts or similar, but they do require more effort and skill to apply properly. Info on t-nuts here.
- Wood glue or a bonding adhesive like PL premium. PL premium comes in a tube that requires a caulking gun.
- Driver(s) of your choice
- Terminal cups and or binding posts
- Crossover(s), (optional). Crossover design from scratch can be tricky and one of the most challenging aspects of a build. Look for others designs that have been proven first. If you chose to design your own, take the time to understand the concepts and ask questions.
- Grill materials (optional)- speaker cloth, metal grill, wood strips (1x2's are popular), magnets and/or grill pins
- Sandpaper or sanding discs (optional)
- Wood filler, bondo, or some type of putty to fill imperfections if needed (optional)
- Paint, veneer, and/or stain are popular choices (optional. Some may use a primer to help seal the wood before painting. A good discussion on finishing options around paint, stain, and duratex can be found here. Help/tip on creating a mirror/gloss finish here. More finishing tips here.
- Feet for enclosure (optional)
- Wire for drivers, terminal cups, and crossovers.
- Polyfil or pillow equivalent. Why do I need to polyfil? Read this.
. Video help
Creating cut sheets
- Free software!
Some help on creating custom baffle cutouts and driver recesses here
Router selection -
Use 1/2" shank bits whenever possible
Slow start and variable motor speed are really nice options
Budget good router bits - check out kits from MLCS
Assembly tips and best practices
good articles as recommended by members:
What is Fiberfill and how does it affect a subwoofer enclosure?
What material(s) are best for lining speaker/subwoofer cabinet walls?
See this thread
Best practice: "zip ties to keep the series connection wire from bouncin", from http://www.avsforum.com/t/1453468/st...#post_22860754
Also from same thread, simple DIY 90deg jig to keep holes square when drilling:
Best practice: Cover your (poly)fill with thin netting, from http://www.avsforum.com/t/1415823/2-...#post_22583001
Best practice: "I used a 2" flush edge bit for the edges, bondo for the larger cracks, a blunder on my poor edging skills, and screw and nail holes. Then I shaped the edges with a 3/4" round-over bit on the outer edges and a 1/8" round-over for the edge that surrounds the driver.". from http://www.avsforum.com/t/1453468/st...#post_22860764
Fastener to mount driver
Other on paint:
Tip: Zip tie for easy remove heavy driver http://www.avsforum.com/t/1460745/ul...#post_23100837
How can I make perfect grills?
What driver(s) should I use?
The brand and model(s) of popular options will change due to the nature of the electronics industry, but there always seems to be a few forum favorites, based on developments, sales promotions, and vendor availability. This will vary greatly upon the listening environment, usage, and other factors.
Thanks to our friend and valued member Josh Ricci, a number of popular options have had standardized testing performed (subwoofers) at his site www.data-bass.com
. This is a GREAT resource and an awesome starting point for someone looking for drivers within their budget.
offers a huge assortment of options that are often discussed here on the forum.
What are the benefits to using multiple (subwoofer) drivers?
Smoother frequency response, reduction of room modes/nulls, and of course, additional output.
Paul Spencer's Bass Integration Guide
There is also a nice multi-sub thread
by our own kgveteran. He uses an interesting approach of filling in a rather deep and broad null with additional subs using the MiniDSP to bandpass filter the signal applied to the filler subs.
How do I build a crossover? Where do I start?
Crossover FAQ - includes info as to how to 'decode' schematics
More crossover info and examples
What type and size enclosure should I use? How can I best predict how it will sound?
First off - based on your priorities and/or building experience, one must choose a design type. Popular configurations are sealed, vented, and horn loaded. Infinite baffles are also a very popular option. Each have their pro/cons with regard to efficiency, output, size, and build complexity.
Sealed vs. Bass Reflex vs. Horn by Josh Ricci
Ported enclosures - what size ports do I need? Help here - http://www.subwoofer-builder.com/port-flares.htm
Infinite Baffles by Pitviper33 - "If you own your space and have the flexibility to make some modifications, you don't have to limit yourself to building a subwoofer that sits in your room. With an infinite baffle subwoofer you make the subwoofer part of your room by installing it into the floor, wall, or ceiling. These type of subwoofers have the best WAF of all, because they can be completely hidden from view. And because the drivers don't have to work against the air spring of a box, you get ultra low distortion and ultra deep bass output for very low cost. Check out the FAQ at the "Cult of the Infinitely Baffled" for more details."
Infinite baffle FAQ
I'm interested in building a Tapped Horn - Where to start?
Download the Hornresp software here
Check out this great tutorial
using hornresp from lilmike.
More tutorial/information on starting with hornresp here
Without building and measuring each prototype directly (this would be a LOT of work), we often rely on modeling software to best predict how a certain system will perform. A popular option on here is the WinISD modeling software.
Setting up new drivers in this software may seem like a daunting task at first, but a detailed guide can be provided a HTshack here that provides step by step instructions:
Q: I downloaded WinISD, entered driver information, tried to save and am getting errors, what do I do?
A: Make sure all fields are clear, then:
- enter qes then hit tab, enter qms
- hit tab a couple times and let it calculate qts
- hit tab a few times to move to mms
- enter mms, re, bl, le, sd, xmax, and pe
- by using tab after entering each data, it will calculate what it needs to
Q: I'm running WinISD on Windows 7, and when I try to exit the program, I get the error message "Access violation at address 00000000. Read of address 00000000". I have to use Task Manager to shut it down.
A: Download the latest version at http://www.linearteam.org/download/winisd-07x.exe
. This version is not linked from the Linear Team home page, but WinISD author Juha Hartikainen links to it from his Twitter account
Once you’ve nailed down the appropriate volume for your enclosure and drivers, we can apply a tool to determine volume for given dimensions. A popular tool like boxnotes will determine box volume based on dimensions you’ve determine meet your room’s size constraints and/or WAF acceptability. This software also provides cut dimensions for each build.
Once we have our cut dimensions, we can use a modeling program to determine the most efficient ways of making cuts with our stock available. A tool like CutList will provide a means to map out your cuts:
What amp(s) should I use?
There are a few considerations that one must observe when shopping for an amplifier?
I have an SPL goal in mind at my listening position. How much power do I need?
Question: I want to use a pro amp but I'm concerned about fan noise. I don't like the idea of modding my amp internally or replacing the fan(s). What should I do?
- Power rating: Often one must stay within the confines of the recommended power level of the chosen design.
- Impedance match: Does your total impedance of your system match the constraints of the amplifier you’ve selected? Is this the most efficient use of the amplifiers design?
- Size/type: Do I want a plate amplifier that is built into the speaker cabinet or a separate, standalone rack or shelf mounted option?
- Power demands: Pay close attention to the current (and voltage) available in your listening area of choice. Many amplifiers require dedicated 15, 20, or 30A lines and some even operate on 240V.
- Quality/vendor reputation: Having 30,000 watts is no fun if it breaks all the time or requires constant repair. Choose a reputable vendor who will provide support for years to come should an issue arise.
- Cost: OK, you’ve designed a 32 x 18” subwoofer system and plan on 30,000 watts to support it. You’re wife has agreed to give up the space and you’ve got 400A electrical service at your pad. Obviously cost is a significant consideration for most of us.
Many of us in this situation are building relay boxes to turn the amps on/off in a remote location using the 12V output (trigger) from the receiver. Here are a few examples:
Modded EP4000 with internal relay
You will need to ensure the wiring of your subs conforms to the recommended range by the amplifier manufacturer? You can use the following http://www.the12volt.com/caraudio/woofer_configurationsm.asp
[/URL]to derive the final impedance by connecting your drivers in series or parallel.
Wire size selection -
Series? Parallel? How do I determine how to wire my subs? What possibilities do I have?
Advanced Speaker building and design considerations:
Recommended reading for high-fidelity uniform-directivity speakers and waveguides:
PI speakers FAQ
More Crossover information, more on gain setup, etc.
TWEAKING AND POST SETUP
Information on setting up gain structure can be found here
courtesy of Ricci.
How do I measure what I’ve built?
A set of measurement tools are very handy when it comes time to tweak your system including speaker placement, phase adjustment, EQ adjustment, etc.
A few popular options:
REW - A nice freeware choice that only requires a microphone and a few cables to get started. If you're on a budget, this is the place to start with simply a Radio shack meter. http://www.hometheatershack.com/roomeq/
Good guide for REW and all the components one would need can be found here
. Creator: omegaslast
Omnimic - a bit less hassle to get started, but a higher starting $$$ ticket.
A smooth frequency response and/or tailoring the curve to your personal taste can drastically improve the enjoyment of your system. After measurement, the next logical step is to allow some type of equalization.
Minidsp - http://www.minidsp.com/
Beringer DCX - http://www.behringer.com/EN/Products/DCX2496.aspx
How to extend the high pass filter below 20hz in DCX2496