LF content of Danley's great recordings

[bentoronto]

Tom Danley's website has four recordings. He mentions that the fireworks recording was made with a mic "invention" he is developing. The content is fabulous and my thanks to Tom.

four .wav download files

I've been "looking" (and posting) at several recordings recently on my Mac MacCRO spectrum analyzer. Here're comments on the wonderful and realistic Danley recordings.

1. Fireworks half a mile away. Some bit of low content, but big booms are 30-45 Hz. If that is where your system is strong, you'll be experiencing bone-shaking, chest pounding transients.

2. Train starting. Some content below 20 near start, bulk 15-50 ("engine oil range") but most of strength 25-35.

3. Coal train. Diesel engine has sharp peaks at 25 and 45.

4. Harley bike. Not much happening below 80-90. These may be stock mufflers, not as obnoxious as some aftermarket pipes (I've been a BMW biker for the last 44 riding seasons).

It is easy with organ or any other music, to think you are hearing earth-shaking subsonic bass when, in fact, the content is really well above or even like the Harley, as high as 80-990 Hz. With the excellent Danley recordings, you can get a really satisfying impression (indeed, misimpression) of super low bass (rail cars thumping about) when played on a system that is strong down to say, 38 Hz, but not much below. And I am am not talking about mistaking 3rd harmonic distortion for 20 Hz fundamentals.

One conclusion is that there are many who still believe the quality of a system depends on being 20-to-20k and feel unfulfilled till they think they got there... they think they can hear it or otherwise know it when they got there.

Footnote. Some of the stereo is as much fun as my 1960's Audio Fidelity recording of trains. While I have no basis for direct comparison, my 110 Hz mixed bass signal going to one part of my music room doesn't seem to impair the localization of these bassy objects as they move across the front virtual stage.

[Don Snyder]

Good post !!!

I downloaded these four files plus the Nagle version of Bach's Toccata in D minor. Since my big horn can't handle large doses of this material, I had to
make a version better suited to the capabilities of my speaker.

Using GoldWave, I saved the file as a "mono" file, then saved it as a "stereo" file. Then, I chose to use the left channel as the subwoofer channel and the
right channel as everything else. I HP'd the left at 30, LP'd the left at 120, and HP'd the right at 120. After adjusting the volume, I was ready to test.

I went to the hall to set-up a little earlier than usual, and pushed 100 watts per channel of train sounds thru the speakers ... WOW!!! It didn't sound like
the train was going past the outside of the building, it sounded like the train was going THRU the building.

[Don Snyder]

Sorry, that was Magle, not Nagle.

[David_Web]

Too bad the firework recording is still the inverted/clipping version.
In the DTS-10 thread over at AVS this was pointed out and Danley promised to fix it.
Danley DTS-10 "Super Spud" DIY kit - Page 21 - AVS Forum

[bentoronto]

Originally Posted by David_Web

Too bad the firework recording is still the inverted/clipping version.
In the DTS-10 thread over at AVS this was pointed out and Danley promised to fix it.
Danley DTS-10 "Super Spud" DIY kit - Page 21 - AVS Forum

The recording seems pretty soft relative to volume control settings for music. But I couldn't say what the dots-and-dashes are up to. There is only one digit-busting peak, near the end, that seems to push the limits. Hard for my ears to know if the "sound" at that spot is unrealistic since it feels, sounds, and shakes objects in my room in realistic ways. I'll listen more closely at normal hearing levels to that thump to check it out.

I can vaguely see how one might argue that inversion of the explosions sounds getting to my ears just might make a difference for the perception of an explosion at say 5 Hz (200 foot wave). Of course, that's unlike the opinion generally held apropos music, even when people can detect an ABX Test difference.

But ultimately, there's no convention or control (or needs to be) as to what gets to your left or right ear for a home music system. As to conventions for pulses leaving the drivers, there might be conventions and they might be honored in movie theaters, but unlikely any too often honored in homes.