Diy AMT

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there is a liner. they say you can cut pices out of it since it has a liner, so nothing is gone stick while you try to cut. but its dutch ofcourse :) might had to say that part

all there stuff has liners(all the sticky stuff) so all tapes and these huge tapes of 50cm wide :) 50 meters long:) haha some roll thats gone be


it is not even that expensive to be honest. 25 M2 for 60 euro :) thats pretty ok if you ask me. going to last half my life time :), but i dont want to buy 60 ero of stuff again, i might do it later this month or so :) i know me :)
 
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Just one more .
12-10-1_kit_.jpg
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12-10-1 kit. 1,2 ohm diff. spl. range

Bernt
I hope that you are protecting your ears, 145 dB is definitely gonna get you a hearing impairment.
 
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im not sure i use a Umik and a cal file to. a quad has Sensitivity: 86dB SPL for 2.83V rms at 1 meter


if i set my ouput for 2.83V i run a sweep and end up with over 100 db on the rew meter... not sure if there could be 14 db room gain ? over the entire frequency band
 
I was referring to båndsei's measurements; AFAIK he is using a calibrated UMIK and REW.
Also, I would prefer to measure with 1 W in and not 2,83 V that corresponds 1 W at a 8 Ω load.
When comparing sensitivite that is. Otherwise the resistance should be stated as båndsei does.

yeah i can imagine , 1 watt is more easy to compare. but just saying i am using calibrated umik and rew as well, i dont see the difference but ok.
 
yeah i can imagine , 1 watt is more easy to compare. but just saying i am using calibrated umik and rew as well, i dont see the difference but ok.
Sorry, I thought that by "im not sure i use a Umik and a cal file to." you meant that you didn't use a UMIK and REW.
Could it be that for some reason REW has "forgotten" the calibration file or perhaps it wasn't loaded in the first place? Sorry for asking :cannotbe:.
 
140 would drive you out of the room no matter who you are.

Belive me.

I have done some high power testing. The midrange and up will cause you serious pain a little over 115 to 120.

Even with ear plugs 145 is absolutely nuts.

But.

If it is nearfield that is a totally different story.

Placing a mic within 4 or 5 mm of the diaphragm will generate a similar number.

The only point of argument I could make about the measurements id that they are made with a reference voltage instead of of one watt one meter. But as I understand it there are many different impedances.

The ones that are close to 2 ohms are quite high in relative SPL in relation to the ones that are closer to 6 ohms in impedance.

Awesome work.
 
I think something is wrong with the last measurement.
It was in the same series of measurements and the settings where the same.
Mini DSP writes that the UMIK-1 measures up to 133 db ,and my amp might not like the low impedance.
I had the idea to "calibrate" the impedance to 8 ohm for all diaphragms with series resistor.
Will try it with the latest measurement ,reading 145 db.

Bernt
 
I don't know the shipping and import costs but this:

Dayton Audio iMM-6 Calibrated Measurement Microphone for Tablets iPhone iPad and Android

https://itunes.apple.com/us/app/iaudiotool/id580740399?mt=8

or

https://play.google.com/store/apps/details?id=com.julian.apps.AudioTool&hl=en

Along with this:

Dayton Audio iMM-6 iDevice Calibrated Measurement Microphone

Here you find the cal file.

These two items in a smart phone can give you pretty outstanding measurement capabilities.

Oh and they fit in your pocket!
 
Hi Bernt, i got the massive 50cm x 50 meter roll tape :) but i wondered how do you laminate? i need to make a4 paper sized laminates to use in the printer. but it is pretty hard to laminate this big size on 6 micron mylar

btw the backing is a PE kind f material, it is really easy to get it off. and for fun sake made one membrane with the foil as carrier. it did not come off , but once you peel it it is pretty easy.
 
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