Loud Noises at Night

[Mark Seaton]

Hi guys,

A few weeks ago I mentioned elsewhere that Tom Danley had given me an early copy of a recording he made at night on the 4th of July. Tom has some cool microphone designs he has been playing with, and this uses one of them that gives a rather impressive realism to being at the live event. Yesterday I got an e-mail from Tom that a clip of this recording has been posted so others can download it and play.

This is an uncompressed recording, and the dynamic range is huge at roughly 70dB.

The peak to average ratio is around 40dB. This means it doesn't sound terribly loud, but the peaks can easily be pushed to clip a system. There is also a lot of low frequency energy in it.

Translation: BE VERY CAREFUL!

On a system with good dynamics and extension this should sound very realistic with the expected shockwave-like sensation if reproduced properly. The explosions shake just about everything in my house at the point I'm starting to clip the subwoofer amp. Again, start at moderate to lower levels. Other than the last minute it's not the most exciting thing, but quite realistic and interesting to play with.

I'm expecting Ilkka to have a few spectrograms plotted before the end of the weekend.

Here is what Tom Danley added in his e-mail:

Hi all

On the 4th of July I set up a microphone invention I am working on in my
backyard and recorded the Town’s fireworks display. This was set off
about 3/8 mile away from me and off to one side (the right side). Far off (about
½ mile) in the distance one can faintly hear a band playing at a park..
I thought people might enjoy this recording too as it is an exercise in dynamic
range, so I edited out the last 4 min or so of it and put it on our website for
download.
WARNING this recording goes up to zero dB on the peaks although it sounds
“quiet” so play it quietly before cranking it up. Clipping anywhere in the
chain will usually be audible too.
Also, I tried making an MP3 out of it so it would be easier to e-mail but even
at 320K it absolutely ruined it…. REALLY.
Anyway, unzip it and burn it onto a CD and see what you think.
One last thought, since this is a tough recording to reproduce with most
speakers, try it on a good pair of headphones first as a point of reference.
Have fun

Tom Danley

Fireworks link

http://www.danleysoundlabs.com/Finale4.ZIP

Enjoy!

[bobgpsr]

Mark,

I normally have my Yamaha RX-V2500 set at -30 for normal TV and -10 for most movies. After going through Tom's fireworks recording several times I ended up setting the volume at 0. Really shakes the house (esp @ 3:30 into it) with the PCU @16Hz tune but my BFD never quite got to clipping (red on the input level). I really appreciate you and Tom making this available.

Bob

[Jack Gilvey]

From the title, I thought this was a thread about a randy neighbor.

It's great to have a recording that's not made to be friendly to mass-market systems.

[spearmint]

WOW!!!

Thanks Tom for recording this, and Mark thanks for posting the link.

This has some massive percussion especially from around 3:20 on. It hit me big time…Absolutely Sensational!

The bass just sounds so low during the recording it will be interesting to find out how low it does go.

[Josuah]

Thanks for this post, Mark + Tom. I've been looking for real fireworks material for a long time and now I've finally got some to play with. We'll see how it goes.

[ThomasW]

Here's a link to a spectro plot. It's a link instead of an imbeded image so it doesn throw the thread into widescreen mode

Danley Fireworks

Note that the scale for this is different than those used by the people making these for DVD soundtracks

[Jman]

[Sonnie]

Those two graphs look different to me as far as how low the response is... unless I don't know how to read them.

[ThomasW]

Sonnie

This is a spectrogram (colored plot) of the frequencies in the recording. The recording moves from the top of the screen to the bottom. So the bottom is the first part of the recording, the top is the end.

Look at the white strip toward the top, those are the frequencies being measured. I was looking for really low bass 0Hz-50Hz, jman was measuring higher 10Hz-200Hz. As the SPL increase the colors get more red and darker red.

[Sonnie]

So are these two different parts of the recording? Yours shows red at 5hz and his at 40hz. I was thinking it was the same part of the recording.

[lcaillo]

Jack Gilvey wrote:

From the title, I thought this was a thread about a randy neighbor.

It's great to have a recording that's not made to be friendly to mass-market systems.

I was thinking someone had some leaky FETs in a sub amp.

Maybe the next time things get slow in the shop I can distribute some copies to the mass market...

[ThomasW]

They're different lengths of time and different parts of the recording. The horizontal dotted white lines are the timing marks. Mine shows the final 2.25 min of the entire recording. His shows about a minute and 1/2 of time but I don't know what section it is.

I'm just learning to do this, so his is probably more representitive of the intensity, I was just looking for the lowest bass

[Chrisbee]

But is it art?

[Ilkka]

Thanks for the tip Mark. I hadn't read your thread yet. I'm DL'ing it now and you should have some spectrograms by tomorrow.

[Eeyore]

Played this while my wife was running the vacuum cleaner and the step-child was trying to sleep.

At -10 on the receiver it didn't sound like much here in the basement but everybody ran downstairs to see what blew up.

I will try it louder when I am alone.

Thanks for sharing.

[Ilkka]

Okay. Here's the finale. The absolute SPL should be pretty accurate too (the range goes from -70 dB to 0 dB). I see plenty of DC action! Should sound like the real deal with a capable system.

[Sonnie]

That looks absolutely wicked

I can't wait to get my IB going and see what it's like.


Btw... Randy... welcome to the Shack!

[Chrisbee]

I take it this leaves the fireworks at the end of "V for Vendetta" for dead?

Well, I thought I'd better find out so I downloaded the fireworks show.

It peaks at about 3.30-3.50 in Media Player with some nice, deep, loud bangs!

I chickened out about 1/2" movement on the drivers.

Hee hee. Very realistic!

Thanks

[Eeyore]

Sonnie wrote:

That looks absolutely wicked

I can't wait to get my IB going and see what it's like.


Btw... Randy... welcome to the Shack!

Thank you Sir!

I played this thing at -5 on my receiver today.

Sounds like the real thing.

It's louder and more impressive upstairs than it is here in the basement.

I'm getting another amp tomorrow. I'll play this first thing.

[khellandros66]

Dude, wow that was sweet

My dad just came upstairs thinking that something in my room started blowing up, esp at 3 minutes 20 sec

~Bob

[MrPorterhouse]

Thanks Mark for posting that and to Tom for creating it. Im not at home right now, I'm over at my parents, so I played it on his system. Right now, he only has a 10" MTX cheap-o sub so I can't experience the effect. I can't wait to get home to really hear this.

[Josuah]

Out of curiosity, any idea what SPL was the max at the original mic's location?