How I made my system perfect

This post was literally years in the making. After years of experimentation, I finally created the perfect audio system using used "garage sale" equipment. I experimented with every configuration possible, from speakers to AVR settings over the years. Now I can finally say, it's perfect.

My system is controlled by two AVR systems. Both have HDMI inputs and HDMI decoding. Both are 7.1 systems, but only six speakers are connected to one, and four to the other. I have them connected "daisy chain" style using HDMI. All components are connected to one unit via HDMI, which is connected to the second unit via HDMI, and the second unit to the TV. One unit controls all the front speakers (L, R, C, LH, RH, LFE). The second controls the surround and back speakers (SL, SR, BL, BR).

All my speakers, except for the rears and heights are large speakers. My surround speakers (large) has a frequency response that goes down to 35 Hz and a high of 20 kHz. My front speakers have a frequency response high of 25 kHz but a low of only 120 kHz. I have both fronts connected to an unpowered subwoofer I found that filters all audio from both channels from 120 Hz all the way down to 20 Hz. So, between the unpowered sub and the front speakers, I have a seamless combined frequency response out of my l/r channels of 20 Hz to 25 kHz.

My powered sub has a frequency response that goes down to 35 Hz. On the AVR, I have all speakers (except FL/FR) set as "small". The crossover frequency of the surround speakers is set to 40 Hz. The center channel speaker is a Polk Audio with a frequency response from under 80 Hz and up to 20 kHz. I have the crossover of the center speaker set for 80 Hz.

The front heights and rear surrounds are small speakers borrowed from HTIB sets. These do not have tweeters, unlike the other speakers in the system discussed above. The specs for these speakers say their frequency response is 80 Hz to 20 kHz, but my experimentation shows that I get the best sound out of them when the crossover for these speakers is set to 200 Hz.

THX recommends setting the crossover frequencies for large speakers to "small" and crossover at 80 Hz. I tried this for a while. I also tried setting the large speakers to "large". Trust me, setting them to "small" and the crossover just above the speakers' frequency response low makes a HUGE difference!

The exception to the above rule is if the speaker's frequency response goes as low as 20 Hz. Then, use these speakers as your l/r fronts and set the AVR to "large" for these speakers and the crossover to "full range" for those speakers.

If your AVR has "double bass" or "LFE + mains" as settings, DO NOT use these! If your center speaker sound sounds funny, experiment with the Dolby center speaker width setting. I have mine set for "2" and it sounds fine to me. A "3" setting makes the center sound boomy and a "1" setting makes it sound canny.

Set the AVR controlling your front and height speakers to Dolby Digital combined with Dolby Pro Logic IIz and the AVR controlling the surround and back speakers to Dolby Digital combined with Dolby Pro Logic IIx. Make sure the settings on both units are exactly the same or the sound will not be in sync.

Do not use any of the DSP formats or compression. Make sure you set the distance of all your speakers accurately. Make sure the front height speakers' are set three feet greater than the l/r speaker distance. The added three feet creates 3D sound.

Next, I plan on purchasing better quality speakers for the front heights and surround rears. I'm also thinking about buying a transducer for handling frequencies below 20 Hz. I'm also thinking of adding front wide l/r speakers later on.

Well, the front speakers have the subwoofer that goes down to 20 Hz. The powered sub is a good Polk Audio that goes down to 35 Hz. The trick is to use the powered one for LFE as exclusively as possible. Studios mostly mix the LFE channel's low to 35 Hz. Lower frequencies below 35 Hz are mixed mostly on the front l/r mains. The way I have my system set up, nothing really is lost above 20 Hz on the front l/r mains, but there could be loss of audio under 35 Hz on the l/r surround speakers.

By the way, I have measured everything using software.

I read that somewhere. It could have been Wikipedia. If that's wrong, I need to buy a new powered sub. Only the really expensive powered subs I've seen go as low as 20 Hz. The majority of them start in the 30-40 Hz range. If you go to Polk Audio's subwoofer page, you'd see response range beginning around 35 Hz is pretty much standard.

You talked me into buying a new sub! Lol ... Looking at New Egg, I see one for $99. It's the Yamaha YST-SW216BL. It has a frequency response of 25 Hz to 189 Hz (-10 dB). It's magnetically shielded, (my Polk Audio isn't). It's 100W dynamic power and has a 10" driver. Anything better is at least $130 more. Is this worth $99? Or should I keep looking?

No, that's not what I said. Studios mix LFE effects into the LFE channel that go as low as 30-something Hz. Ambient sounds that drop down to 20 Hz or lower are usually mixed into the mains, not the LFE channel. Of course the sound technicians can mix whatever the hell he/she feels free to mix. When watching a movie mixed in a digital format such as DD or DTS, pay attention to how the low frequencies are mixed (without crossovers that will contaminate the raw LFE channel studio mix) and you will see low frequency ambient sounds are on the mains and EFECTS on LFE.

I made a mistake about the specs of my system. The powered sub by Polk Audio has a frequency response from 31 Hz, a little better than the 35 Hz I posted. It is 300 watts and has a 12" driver. The center speaker has a frequency response of 55 Hz to 25 kHz. I changed the crossover of the center channel to 60 Hz and my system sounds even better now.

Also, because no sub is connected to the amp controlling the surrounds, I fed the back channels through the speaker filters of the powered sub and set the crossover of that filter to as high as possible. On the amp controlling the front speakers and LFE channel, I told it that there were no back speakers, just surrounds. This way, it will mix back speaker content to the surrounds. I then programmed the crossover for the surrounds at 40 Hz so that the powered amp would be responsible for 40 Hz and below on both the surround and rear channels. On the amp controlling the surround and rear channels, I set the crossovers for all four speakers to 40 Hz. Since the speakers I am using for the surrounds have a frequency response that start in the 30's, this crossover is fine. For the rear speakers that are now fed into the powered amp, frequencies 40-160 Hz are now handled by the powered amp. The result is a rich, fully-enveloped sound experience.

No, crossovers are what the amp send to the LFE channel for the other channels. Your amp mixes both the studio mixed LFE channel and the low frequencies from the crossovers of the other channels into the LFE channel for your sub.

Stereo mixes and Pro Logic mixes do not have an LFE channel, but your amp will artificially create one.

I'm talking about raw Dolby Digital and DTS sound tracks before your amp uses its bass management system to mix the crossovers from the other channels into LFE.

It's not finished yet. I just ordered a pair of good speakers to replace the crap speakers I'm using for either my back speakers or my height speakers.

Anyone know where I can order low-price transducers?

My plan is once I am 200% satisfied with the sound, I'm going to test a concept I have that makes 3D video kind of like a hologram, where the screen is like a 3D stage and no glasses are required. The concept has worked in a small scale trial I did. I have since simplified the design - and that's what I will be testing on a 60" stage "screen". If it works, I will patent it and build demos of the system in public areas where people could view it for free and sign up for an installation.

But I believe sound is essential for this. A perfect 3D sound system would match the video and make the video feel more holographic. It should be that a viewer would close their eyes and be able to point to where objects are simply by listening.