DIY Home Theater Speaker System Help

To most home audio enthusiast…

The DIY home theater speaker looks like it would be a very difficult project;

Reality?instrument-quad-v-best-floorstanding-speakers

Like most things; it looks much harder than it actually is.

If we break it into simple step by step terms DIY speakers and DIY speaker projects are pretty easy to complete. They can be very time consuming to build though.

The first thing to consider with a DIY speaker is the type of Speaker System you wish to build.

Will it be a small two way monitor, a medium floor standing speaker, or a large cost no object stereo speakers system?

When you have made the choice of what type of speaker box design to build you can begin making the necessary decisions about the DIY speaker cabinet.

This is a critical step and in many situations it will be much easier to build a cabinet that has already been tested and proven to work well. If you choose this option, we have some diy home theater speaker plans to left in the Products category.

Your DIY speaker box will need to be optimized with several key ares as discussed on this site.

Driver Spacing – Choosing the correct driver spacing is critical for achieving coherence between the drive units.

You do not want to be able to localize which driver is playing a specific sound. The music and effects should be thrown around the room depending on how it was recorded.

Rarely should the sound appear to be coming localized from the speaker on a good diy home theater speaker system.

In general, it is easiest and best to put the mid-range and tweeters as close to one another as possible. The outside of the driver flanges should be nearly touching.

Cabinet Volume – Use the speaker driver recommended cabinet volume for best results.

Cabinet Configuration -ported, sealed, etc. You may already know that a specific speaker driver is usually built to work best in a specific cabinet configuration.

Some drivers were designed to work best in a ported cabinet. Others work best in a sealed cab. And a few are built for dipole use.

This can be calculated by plugging in their TS number into a speaker box calculator such as this.

Speaker Driver Integration – using drivers that work well together. You must pick drivers that will play nice with each other. There are several factors that effect this so we wrote an article about it here.

Crossover Slopes – will depend on the drivers that you choose, their response, distortion, and phase parameters.

If you use drivers in their safe operating ranges you can tailor the slope to fit your needs the best.

If using a digital crossover slope you can tune these slopes until they are the way you prefer. Passive slopes are much more difficult to adjust as it will take a soldering iron, lots of time and patience.

Active, Digital, or Passive Crossover Networks – I recommend digital or active crossover networks and slopes. These offer the DIY home theater speaker builder the greatest level of flexibility in achieving a great speaker system. Once understood, they are very easy to use as well.

Speaker Resonance – and cabinet weight. Here are some articles about this subject.

Cabinet Building Materials –I recommend MDF as the cheapest material to use. MDF is a fairly good building material.

Birch Ply is a better building material than MDF. It is also about three times more expensive. Still, if your budget allows it I would opt for the birch ply option.

There are arguably better materials like aluminum but these are not cost effective for the DIY Home Theater Speaker builder. MDF and Birch Ply will make a great DIY speaker box for your uses.

Speaker Cabinet Hardware – Building a good DIY speaker will not be complete without some good hardware. Go to Speaker Cabinet Hardware.

Speaker Wire Gauge – The size of wire you will need will be determined by the amount of power or watts you intend to push through the cable.

For most tweeters use 14 to 18 gauge. Midrange drivers use 14 to 16 gauge.

Bass drivers use 10 to 12 gauge.

These wire sizes will give you plenty of cable without fear of losing power due to resistance and causing heat build up within the wire.

Time alignment and time coherence – This is easily done in the digital crossover. I will not write about it in regards to passive crossovers. It is simply too time consuming and complex of a project to undertake without a serious investment into testing instruments and use of time.

Phase – Again, very easy to manipulate in the digital crossover. See HTPC crossover below on this page.

Amplifiers – how much power? With active and digital crossovers the power requirements are only considered for each individual driver. Because of this we can use a much less powerful amp as it will only be pushing one driver with no passive components in the path. This will also depend on the sensitivity of the drivers you choose. But generally speaking, you can cut the power at least in half. For example: 50 watts is probably plenty of power for all but the most insensitive midrange drivers. Ten to twenty watts will do it for almost all tweeters. Again, this is assuming you are using active or digital crossovers and have an amp channel for each speaker driver.

Speaker Drivers – Go to this page for more descriptions on speaker drivers and what to look for when buying them.

Speaker Driver distortion – Get the drivers with the lowest distortion figures you can find. Zaph Audio is another great resource to see distortion measurement data for some popular speaker drivers.

Build a Digital Crossover using an HTPC (home theater computer)

Parts Lists and instructions: for a DIY home theater speaker system:

A computer with a large hard drive for storing music. Or a PC with a large external hard drive.

Please don’t assume you will need a high powered PC. A powerful PC is fine if it has a very low fan noise. If the computer will be sitting in your listening room you will need one that is quiet.

There are ways to make PC’s quiet- Google it on the web. Another way if you have a noisy HTPC is to locate it in another room or a closet.

Here is a short linking article about building an HTPC for your home theater speakers.

What you will need to build an HTPC with a Digital Speaker Crossover

1. Fire-wire output card: 1394 firewire with Texas Instruments chip-set. This card will connect to the firewire interface and the computer.

2. Thuneau makes a software download available for sale that works for music and movies. It can also process audio from external sources like DVD and Blu-Ray players sent into the PC from a digital cable. This software cost about $60.00 USD. It’s worth every penny and then some.

A software speaker crossover like Thuneau is necessary to playback movies and games because Foobar cannot process DVD’s or internal gaming audio for your DIY home theater speaker setup.

I personally use both of these software solutions depending on what sound I am looking for. They do deliver sound in different ways.

Foobar sends signal straight out of the firewire cable to the sound card.

Thuneau will make a digital loop outside and back into the PC for gaming. For DVD and Blue-Ray the digital signal will go straight into the sound-card and then into Allocator lite program.

From an engineering standpoint the Thuneau crossover should sound better- it uses a more advanced filter system than the Foobar crossover. But Foobar is a good place to start experimenting, it is free. I use both of them.

Echo Audiofire 12 12 DAC picture

3. An ASIO compliant multichannel sound-card or firewire interface box with INTERNAL ROUTING.

Three devices that I like are the Echo Audiofire 12, the Echo Audiofire 8 and the RME Fireface 800.

If you can afford it The Dave Lavry Blue DAC is even better than those. But it cost close to $4000.00 as an 8 channel DAC.

4. A multichannel preamplifier or receiver with multichannel analog inputs and outputs.

5. An amplifier channel for each speaker driver or ‘way’. A two way speaker will need a 2 channel amp for each speaker.(could also use a receiver) If you are building or using a line array you will not need an amplifier channel for each driver. A line array will need an amplifier channel for each “way”. In other words: a line array consisting a line of 6″ mid drivers and a line of 1″ tweeters. One channel for the mid drivers, one channel for the tweeters.

6. A Home Theater or stereo speaker set with separate binding posts for each driver or driver type(or way). We get many of our loudspeaker drivers from Parts Express – Free Shipping Every Day on most orders over $98 (Restrictions apply).

Speaker Driver Recommendations and the driver selection process. This would be a good place tobuild a DIY theater speaker system. Read this article. 7. RCA or balanced interconnect cables (depending on equipment used) for use with your DIY home theater speaker.(3 pairs for 3 way speaker from interface box to preamp) + (3 pairs for 3 way speaker from preamp to amplifier) This means a total of 6 pairs of interconnects. The best option is eventually making the cables yourself. This to accompany your DIY Home Theater Speaker and the correct terminations on each cable end according to your needs. Parts Express also has many options for Wire & Cable – They carry a large selection of bulk reels to completed cables in every style and length.Speaker cables long enough to get from amplifiers to speakers. Again, make sure you have the right ends or connectors to complete the job. Go to Best Speaker Wire.

Optional: Measurement software

Making accurate measurements is crucial to achieving the highest performance in both Home Theater and Speaker Building. This article explains some of the equipment and software you may need. A short list is also below.

1. A calibration mic such as radio shack SPL meter (sound pressure level)

2. A measurement software program such as room EQ wizard. This lets you make in room measurements and create filters for DIY Home Theater Speaker room correction.

3. A digital switch box such as available through Inday.This allows you to bring multiple audio streams into the computer for playback on your DIY home theater speaker rig. Uses for this would include: a separate DVD player, blu-ray player, or PS3 and have multiple digital sources and inputs.

 




Go to: Build Speakers

Go to: Build your Own Home Theater





CAUTION:

If you do not use a crossover program for the your active speakers you WILL fry your tweeters in a millisecond.

I am not responsible for cooked or destroyed drivers. It would be a good idea that when you are setting the software up and testing for the first time to use a sacrificial full range driver on the DIY home theater speaker make sure you are getting the correct signal out of the given speaker driver.

Home Theater Photos

McCormack RLD 1 preamplifier




Return to Build Speakers from: DIY Home Theater Speaker
Return to Home Speaker from: DIY Home Theater Speaker

Parts Express: Your #1 Speaker Building Resource