Home Theater Design Group Delay and Distortion – Concept, Theory, and Data: “Fix Your Home Theater Room Design!”

Home theater design group distortion and group delay?

Looks like a boring subject doesn’t it?

I’ll try to keep it as quick and clean as possible.

Bear with me… this is important stuff to know.

What is Group delay and group distortion?

Without getting into a really detailed paper on functions, calculations and such, it works like this:

One section of the audio signal (frequency) can be delayed from the rest of the signal.


Part of the frequency spectrum is stretched into a different time position from what was originally recorded.

This where the term ‘delay’ comes from in the term ‘group delay’.

Group delay can happen in your source components, amplifiers, loudspeakers, and even the home theater room itself.

Can you fix it?

Not really…

But you can control the damage.

Specifically, the shape of the home theater room layout is very important

A. How will the room be laid out?

B. What are the features of the home theater room that you would like to showcase?

C. What is the traffic flow in the room?

D. What design elements and decor’ would you like to have in the home theater room?

For more Home Theater Help see this book.

What about room shape and room dimensions: Developing the Home Theater Plan If you are interested in high quality audio, the length and width of the home theater room should not be the same.

Best if the ceiling height is not one half, one third, or one fourth the length or width room measurements.

What happens in the room is that bass modes build up as supported by the dimensions and the room boundaries.

If two or more room dimensions are the same, the frequencies that are excited by the room modes will be either twice or three times as loud depending on how many measurements are multiplied.

It is often necessary to build a mechanical device to help with certain problematic frequencies.

All rooms have room modes and some modes would benefit greatly by using a Helmholtz resonator – read more at Home Theater Plan. These are used to control that specific bass mode peak. These are narrow band devices that can bring down the peaks of a specific frequency.

Room Treatments? Home theater design group (delay fixes) recommendations

The upper bass, mid-range and treble frequencies can be handled with simple devices known as room treatments or acoustic panels.

These usually look like panels or cylinders sometimes placed in the corners and walls of the room.

These can even be built into the home theater room design to give a more appealing look. To read more about Home Theater acoustics click here.

Make some home theater room measurements:

We recommend that you take measurements of your room at the main listening position.

These measurements will give much insight into why your room sounds as it does. This will also give you an idea of the problem areas of your room from an acoustic perspective.

Measurements can help you develop a plan to achieve smoother in room response and improved sound quality.

Speaker Positioning: Home Theater Design Group Recommendations

Speaker positions have a direct contribution to the overall performance of your listening room.

Your best speaker positions are probably not in the corners of the room.

In wall speakers and on wall speakers look nice and stay out of the way. However, the audio performance of these types of speaker systems are not as good as floor standing speakers.

To learn more about speaker positioning go to this page on home theater system setup and speaker placement.

Home theater equipment quality; Getting the best home theater set up

Equipment manufacturers are splitting hairs with technology…

The weakest link in any audio chain is the loudspeaker system.

This is a fact based on average distortion ratings of equipment and loudspeaker measurements!

The loudspeaker system introduces far more distortion and errors into the signal than any CD player, preamplifier, or amplifier of a quality design.

If a home theater amplifier manufacturer had distortion levels and phase errors equal to that of a loudspeaker system they would be considered the worst measuring devices in the industry.

Where do Home Theater Loud Speakers Fail?

1. Group delay and transient response

2. Multitone distortion

3. Doppler distortion

4. Spatial distortion

5. Phase errors

6. Driver Damping

7. Driver response Distortion

8. Crossover distortion

9. Driver ringing

10. Group delay distortion

Here is a related audio article from another author that proves these theories with measurable data.

Go to Home Theater designs and Home Theater Speakers Best article.

Okay, you have a plan to work on home theater design group delay…

Planning out your Home Theater in advance will save you plenty of money and offer you the highest performance.

Jumping the gun, ordering gear, and throwing together a theater room is a great way to waste money and be unsatisfied with your results.

Learn what you can about Home Theater Acoustics, Home Speaker systems and anything related to audio and video in the home theater.

If you do your homework, your excitement will not wear off over the coming years.

Other Related Articles:

About Us: Build a Home Theater page

Build Home Theater

Audio Home Speaker Testing

Digital Audio Speakers

Go to Home Theater Ideas and Home Theater Plan

Return to Best Home Theater System from: Home Theater Design Group Page

Return to Home Speaker from: Home Theater Design Group