What's to chat about?

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T_Gowan
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Re: What's to chat about?

#856 Post by T_Gowan » Tue Apr 06, 2021 11:15 am

This price wasn't Birch ply , just ordinary 1/2 inch , good one side ply. I need to put a sub floor down in a kitchen and dinning room for glue down vinyl plank flooring. going over 100+ year old hardwood and pine floor in my farm house. Hard wood is too far gone and cut up to refinish .

Seth: I have been giging with the t39 and dr200 for several years now , inside bar gigs, out side on the beach gigs, back yard party , you name it. I have been building PA speakers most of my life.(Over 50 years of building) I have never been so pleased with the sound of anything before. The only limitation I have is my cab count for outdoor gigs. But they have been few and far between so I haven't pushed the build yet.
DR200 x2
T24 16" x2
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Seth
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Re: What's to chat about?

#857 Post by Seth » Tue Apr 06, 2021 11:45 am

T_Gowan wrote:
Tue Apr 06, 2021 11:15 am
This price wasn't Birch ply , just ordinary 1/2 inch , good one side ply. I need to put a sub floor down in a kitchen and dinning room for glue down vinyl plank flooring. going over 100+ year old hardwood and pine floor in my farm house. Hard wood is too far gone and cut up to refinish .

Seth: I have been giging with the t39 and dr200 for several years now , inside bar gigs, out side on the beach gigs, back yard party , you name it. I have been building PA speakers most of my life.(Over 50 years of building) I have never been so pleased with the sound of anything before. The only limitation I have is my cab count for outdoor gigs. But they have been few and far between so I haven't pushed the build yet.
I wanna say I paid about $25 a sheet last time I bought CDX 5 ply sheathing plywood. Just looked it up on the HD site... now $60/sheet. So, it looks as though your cost increase isn't isolated.
Shoot! Ply cost will now be $105/cab to build 28" T39's :cussing: (instead of $43, based on a 4 cab build with the cheap-o ply) LOL.

Looks like even the OSB has doubled in price too.

I vote the vaccine be made available to Healthcare workers and Lumberjacks. Let's get those boys back to work.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Re: What's to chat about?

#858 Post by Seth » Wed Apr 07, 2021 10:42 am

So, here's an interesting thing... I'm fairly convinced that I'm able to hear down to 16Hz, where the perception of a tone comes and goes. 17 & 18Hz fairly reliably. But, what about the other end of the spectrum? Wanna say somewhere around 16kHz is where I lost it. But, then I realized the source (ear buds) may not be working up there. So, I'm really not sure what I can hear up to. Then I watched this video, that suggests perception all the way up to 40kHz!?!? It's becoming more and more clear to me, that the 20-20kHz window I've been taught throughout the years is really a rough estimate based on (???) common sounds at common levels... or something to that effect.

Can humans actually hear beyond 20k?





Thought that was interesting.



.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Tom Smit
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Re: What's to chat about?

#859 Post by Tom Smit » Wed Apr 07, 2021 9:31 pm

I watched that Dave Rat video when it first came out. Rather interesting, I must say.
TomS

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Seth
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Re: What's to chat about?

#860 Post by Seth » Thu Apr 08, 2021 1:07 pm

Tom Smit wrote:
Wed Apr 07, 2021 9:31 pm
I watched that Dave Rat video when it first came out. Rather interesting, I must say.
I've been watching his vid's for a good while too. Always laid back, interesting, informative, and thought provoking. He's an interesting guy. I watched one of his videos last week where he rode his bike around the 2018 Coachella Music Festival as it was being set up. I can't find the video now and wonder if he took it off his channel for some reason. Anyway... I had absolutely no idea he/his company was THAT involved and THAT big. Something like 6 stages, all with huge top of the line systems. Monstrous delay towers, underground fiber optic networked audio. Absolutely amazing cutting edge sound tech and overall a massive production. WOW. Yet, still, he's just a laid back surfer guy that seems to have very little ego about anything and is continuously inquisitive and passionate about the whole subject. Really, the very definition of humble. Fascinating guy. I'd really enjoy meeting and speaking with him. More so than any of the talent he's worked with.

Did you happen to see that video?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

himhimself
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Re: What's to chat about?

#861 Post by himhimself » Thu Apr 08, 2021 2:13 pm

2xT30 (20", 3012LF)
2xT30 (21", 3012LF)
4xOtop J-array (Beta12, melded/straight piezos)
Truck Tuba (MCM)
Next up: 2xJack12 or family of table tubas

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Seth
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Re: What's to chat about?

#862 Post by Seth » Thu Apr 08, 2021 4:13 pm

himhimself wrote:
Thu Apr 08, 2021 2:13 pm
Try this:

That's a pretty cool video too. I enjoyed the little conversation at 13:35... Employee:"here's something I'd like to do next year" Dave: "oh, yeah yeah yeah, we can do that tomorrow"

In the other video I was talking about (pretty sure it was 2018 Coachella), it was pre-show, the place was empty other than stagehands, and he gave a pretty detailed description of each stages set-up and talked about managing sound and interference between all the stages and acts. It was really quite impressive. I'd really like to meet that guy sometime.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Tom Smit
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Re: What's to chat about?

#863 Post by Tom Smit » Thu Apr 08, 2021 9:34 pm

Seth wrote:
Thu Apr 08, 2021 1:07 pm
I watched one of his videos last week where he rode his bike around the 2018 Coachella Music Festival as it was being set up.

Did you happen to see that video?
I did.
I watch most of his videos. I have even shared some that he had with his daughter, with my daughter, because those particular videos had a familiar feel to them.
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Seth
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Re: What's to chat about?

#864 Post by Seth » Fri Apr 09, 2021 2:08 pm

Is what I'm seeing in the video below a visual representation of sound traveling? Or, perhaps an effect of progressive scanning video? What do you think? See the slight wave in the crowd that starts at the stage and propagates to the camera position? Interesting, me thinks.

Imbedding disabled by the creator. Oh well.
https://youtu.be/5-gTgJ7xilA?t=47
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Grant Bunter
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Re: What's to chat about?

#865 Post by Grant Bunter » Fri Apr 09, 2021 4:26 pm

No, it's sound travelling.
At the speed of sound.

It's the reason one might expect to see delay stacks.

Is there a component of reaction time as well, well, hard to know, the human mind is extraordinarily adaptive...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
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Bill Fitzmaurice
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Re: What's to chat about?

#866 Post by Bill Fitzmaurice » Sat Apr 10, 2021 8:22 am

Seth wrote:
Wed Apr 07, 2021 10:42 am
So, here's an interesting thing... I'm fairly convinced that I'm able to hear down to 16Hz,
You can't. What you're hearing if you play a 16Hz tone is harmonics, primarily the 2nd and 3rd at 32 and 48Hz. If you don't think there are harmonics present, there are, the speaker itself creates them. Even if you could hear that low the speaker and amp requirements are prohibitive, due to equal loudness. Even elephants can't hear that low. They do communicate over long distances with very low frequency sound, but they don't hear it. They feel it, with their feet, via ground conduction.
At the opposite end of the spectrum younger people can hear to around 20-25kHz, but that drops down to 15kHz or so by the age of 25, gradually going lower than that with age. Even if one could hear 20kHz and above it's moot, because it's not present on recordings. The gear used, starting with the microphones, don't go that high. Equal loudness is also an issue with high frequencies. It jumps off the chart above 15kHz.

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Seth
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Re: What's to chat about?

#867 Post by Seth » Sat Apr 10, 2021 12:04 pm

Bill Fitzmaurice wrote:
Sat Apr 10, 2021 8:22 am
Seth wrote:
Wed Apr 07, 2021 10:42 am
So, here's an interesting thing... I'm fairly convinced that I'm able to hear down to 16Hz,
You can't. What you're hearing if you play a 16Hz tone is harmonics, primarily the 2nd and 3rd at 32 and 48Hz. If you don't think there are harmonics present, there are, the speaker itself creates them. Even if you could hear that low the speaker and amp requirements are prohibitive, due to equal loudness. Even elephants can't hear that low. They do communicate over long distances with very low frequency sound, but they don't hear it. They feel it, with their feet, via ground conduction.
At the opposite end of the spectrum younger people can hear to around 20-25kHz, but that drops down to 15kHz or so by the age of 25, gradually going lower than that with age. Even if one could hear 20kHz and above it's moot, because it's not present on recordings. The gear used, starting with the microphones, don't go that high. Equal loudness is also an issue with high frequencies. It jumps off the chart above 15kHz.
Yeah, we've had this conversation before and it's out of pure reverence for you and your knowledge that I'm not 100% convinced that I'm hearing what I think I'm hearing.

Here's where I get caught up and have trouble taking on the belief that what I'm hearing is purely harmonics... If I start with a 50Hz sine and step down in 1Hz increments, there's a clear difference and linear occurring tone for each step. The only way what your saying makes sense to me is if every sine frequency is heard as harmonics. Also, I feel the pressurization of 15Hz yet there's no formation of a perceived tone. So, I have a hard time grasping the concept that it's harmonics I'm (barely) hearing/perceiving at 16Hz, yet 30Hz and 45Hz harmonics don't occur at at 15Hz.

I'm curious, if you put earbuds in and step sine waves lower and lower, where do you stop perceiving a tone (whether it be harmonics or not) ?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Re: What's to chat about?

#868 Post by Bill Fitzmaurice » Sat Apr 10, 2021 12:24 pm

Every frequency is heard as a fundamental sine wave plus harmonics. The higher the frequency the more dominant is the fundamental. The lower the frequency the more dominant are the harmonics. The worst tool possible tool for testing this is your ears. You must have an RTA showing what's being produced, and then compensate the result in line with equal loudness. For a 16Hz tone to be heard at the same level as 32Hz it would have to be some 10dB louder, and for it to be heard at the same level as 48Hz it would have to be some 20dB louder. If your speaker is flat to 16Hz it would take ten times the power at 16Hz as 32Hz, one hundred times the power at 16Hz as 48Hz, and that flat to 16Hz is a mighty big if.

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AntonZ
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Re: What's to chat about?

#869 Post by AntonZ » Sat Apr 10, 2021 1:47 pm

A weird way of how I came to realize that this is indeed the case is when I completed my T18, many years ago. I had never heard this type of subwoofer before and these folded horns have a way of naturally filtering out harmonics. There probably still is some left, but much reduced in level compared to more common types of sub cab. I thought I knew what 40Hz sounded like before I completed my modest T18. After completion I knew that I had no idea what it actually sounded like. A clean and proper 40Hz is actually quite a bit lower than most people think it is.

A similar thing happens when people start designing their own bass cabs. They read on the internets that the fundamental frequency of a low E on bass guitar is 41Hz. So they want to build cabs that reproduce that 41Hz. What we typically hear when a bass guitar plays low E is mostly 82Hz and higher harmonics. Few systems other than properly big and well designed PA's in larger rooms will reproduce the real 41Hz with authority. Let alone the 31Hz of low B on a 5 or 6-string bass. And it doesn't even remotely sound like bass guitar at all.

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Seth
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Re: What's to chat about?

#870 Post by Seth » Sat Apr 10, 2021 2:47 pm

I should reiterate that I've only experienced the 16Hz thing with earbuds. I'm really curious what you guys "hear" when you test the bottom end of your hearing with earbuds and sine waves. The lower I go the physical sensation of pressure in the ear canal becomes more and more prominent and at some point that sensation remains but the perception of a tone is gone. It's not like I can clearly make out one frequency and the next one lower is just gone. For me, it get's more and more faint. But, it's not like it get's too quiet to hear, it just reaches a point that the perception of a tone doesn't occur and it's there then gone, then there and gone again. Do you experience anything similar to this? At what point do you guys stop perceiving the presence of a tone?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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