Weltersys,
My mic tops out at 114dB and this is easily achievable with little power - so I would have to go outside and do it farther away. Unfortunately, the neighbors would frown on high SPL testing and it is winter here in DC area now. The distortion would rise basically linearly with SPL so with HD at -50dB to even -55dB at circa 100dB, 120dB would be about -30dB etc. predicted SPL is 108dB at 1w and driver can handle say 30 watts or circa 6 x 3dB = 18dB on top of 108dB or 126dB at max power. With losses inefficiencies and compression I think probably 120dB RMS and 126dB peak.
My mic tops out at 114dB and this is easily achievable with little power - so I would have to go outside and do it farther away. Unfortunately, the neighbors would frown on high SPL testing and it is winter here in DC area now. The distortion would rise basically linearly with SPL so with HD at -50dB to even -55dB at circa 100dB, 120dB would be about -30dB etc. predicted SPL is 108dB at 1w and driver can handle say 30 watts or circa 6 x 3dB = 18dB on top of 108dB or 126dB at max power. With losses inefficiencies and compression I think probably 120dB RMS and 126dB peak.
Thanks. Cutting foam core straight just requires a sharp razor and a good straight edge. I actually use a piece of long masonite hard board as a straight edge. A drywall installation metal straight edge works well too. I used to use an xacto and sharpened it but now use break off tip utility knives.
xrk971,
I'd love to believe your estimates, but you wrote:
"The fundamental is about 98.6dB with a little over 300 milliwatts power driving it (at .5 meter)...that's 0.19% THD at equivalent 92.6dB at 1m!"
That is only roughly 97 dB one watt one meter sensitivity, 11 db below the sensitivity you are using to base output on in your statement above.
IIRC, you are using something on the order of +10dB to get the HF to equal the mid level, so HF would require a lot more voltage to achieve the same SPL.
I'd be very interested in seeing distortion levels starting at 2.83 volts (no EQ, but with the HP filter normally used), then increased in 3 dB increments till 114 dB or the driver power limits are approached. You may find your assumption that distortion rises linearly with level will change
.Are your distortion results at 1/2 meter indoors quite different than at one meter?
Art
Thanks
Wel I did some measurements outside I still got some peaks and stuff and I think the transmitter is a cause in the trouble because I do hear the rattle from it and get it not out, the mic picks that up and needs to be untouched with filters.
I did also with the headphone but is peaky to, I have bought the mic capsules from a chinese supplyer from ebay, do I have here a problem? or just my house room is very peaky one, the woofer did also get a canceling on 52 hz and not to find the cause yet.
The Tascam US-122L do have quite some noise also, so I have here a dirty evironment with that antenna, I go take steps to get it removed because also
I am sensitive for radiation, it can seriously disturb my sleep, it works like koffie for me that radiation on some strange way preventing deep sleep, that is examinated in a hospital and reason that the judge have place me here because it was clean, until 16 months ago.
Buying a mic is not a option because the Siegfried mod is quite good, possible even better then a pro mike.
Picture three is measurement in mouth of trynergy horn, the wildness above 10 Khz can be the mike or resonance horn or cone breakup.
regards
kees
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I have bought reticuled sealed foam Yoga carpet : 15 mm thick . I thing density is no more than 30 Kg and Shore A no more than 20/30 (seing some web site about such sport stuffs for Yoga, gymnastic/bodybuilding...)
I found very good EVA foam but always too expensive; e.g. 50 to 80 euros for only 2 walls ! But density can be between 180 to 350 kg and Shore A between 50 to 90 !
Have the two 10F/84 in 2 or 3 weeks !
How can I trace the wall from the Pdf ? Is there a possibility to print it on several papersheet on scale 1 through an A4 printer then make a cardboard pattern to cut the foam or did you go another way ??? (not sure to have perfectly understood the way to proceed from the two files plans ! Sorry for the two cents !
Hey the foam is Orange 70s'... pre disco color !
I found very good EVA foam but always too expensive; e.g. 50 to 80 euros for only 2 walls ! But density can be between 180 to 350 kg and Shore A between 50 to 90 !
Have the two 10F/84 in 2 or 3 weeks !
How can I trace the wall from the Pdf ? Is there a possibility to print it on several papersheet on scale 1 through an A4 printer then make a cardboard pattern to cut the foam or did you go another way ??? (not sure to have perfectly understood the way to proceed from the two files plans ! Sorry for the two cents !
Hey the foam is Orange 70s'... pre disco color !
In Adobe Acrobat use the "Tile Print" feature where a large print is made with several smaller "tiles" and composited together. Adjust the scaling on one sheet to get the scale correct. Trial and error - but if your printer dpi is accurate, it is usually pretty good. Adjust scale so throat dimension is 2.0 inches (a little off is no big deal). Then tape the quantity 12 or 16 x A4 pages together to make a big print. Lay it on your foam and use a ball point pen to poke holes along the outline you want to draw every inch or so. Then trace the curve on the foam following the "connect the dots" method.
Page 100 woot!
Final Exams,
House hunting with my gf. Hopefully one with a workspace or garage.
Waiting on new Faitalpros from P.E.
Build Trynergies
Question
If one were to follow the path of the horn outwards on the sides with absorptive material like fiberglass, and have almost a 'cabinet' build around the trynergy with fiberglass could this absorb the non directive frequencies that wrap around in any substantial way?
Final Exams,
House hunting with my gf. Hopefully one with a workspace or garage.
Waiting on new Faitalpros from P.E.
Build Trynergies
Question
If one were to follow the path of the horn outwards on the sides with absorptive material like fiberglass, and have almost a 'cabinet' build around the trynergy with fiberglass could this absorb the non directive frequencies that wrap around in any substantial way?
Regarding ploting, i used this online tool
https://plot.ly/plot
2D image, printed it to multiple A4 pages from Adobe Reader, then cut and glued to get a full tractrix curvature. It is not perfect tool but it is free and easy to work with.
I will post Visaton frs8m measurements this week, i did two 220tractrix horns last weekend. Back chamber is not done yet.
https://plot.ly/plot
2D image, printed it to multiple A4 pages from Adobe Reader, then cut and glued to get a full tractrix curvature. It is not perfect tool but it is free and easy to work with.
I will post Visaton frs8m measurements this week, i did two 220tractrix horns last weekend. Back chamber is not done yet.
That plot program gives an xy line plot of a function so good for the flat panels and where the curve is on the 2d projection of the angled panel to a 2d flat but how do you get the flattened 2d representation of the curved panel which intersects an angled flat board? That is where I had to use 3D CAD model and then flatten the curve to get the cut plan.
Tell us this is not your DAC-ADC loopback.
SL has long ago switched to using Earthworks measurement microphone.
No it is'nt, this is the mike measurement, picture is the soundcard correction file loaded in REW I do not now how to see it in Holmimpulse.
I do not remember it is close of not but is was outside, possible 1 meter.
also you can see the mike correction file in it, for the WM-61A. the file is for the Tascam usb soundcard.
regards
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Here the measurement of the audio AD-ADC through Holm Impulse.
that was the card who did measure also the horn in previous post.
And a test with a wire so I can see the antenna do disturb things, (RF filter removed.) it is middle picture, strong wifi right? and yes it comes from the states and is for company cardens, store centra, not for ordinairy homes, so I have start go to court as a last resort.
And a test with the phillips in a 17 liter box with 5.11 wide and 4.2 long port, so I can see what it will do in the horn, so I can just put the port in and go on with it.
regards
that was the card who did measure also the horn in previous post.
And a test with a wire so I can see the antenna do disturb things, (RF filter removed.) it is middle picture, strong wifi right? and yes it comes from the states and is for company cardens, store centra, not for ordinairy homes, so I have start go to court as a last resort.
And a test with the phillips in a 17 liter box with 5.11 wide and 4.2 long port, so I can see what it will do in the horn, so I can just put the port in and go on with it.
regards
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I did use a short antenna wire, just 3,1 cm long, that is 300 : 2400 : 4 for 1/4 golflength, but the pulses are the problem, who is am modulated and so do disturb, like your mobile phone does when close to a box or amp.
the 2400 Mhz does nothing on his own, to weak also.
I have not a 50 leak, I have earth, but I do hear in box the rattle of that box, possible because of the nabure do not like me has a transmitter pointed on me, this is afcouse not nice, and so he has to go to judge on 4 december.
PS I do send you a script later , the script I have is with two 12 inch woofers, the older one who is changed to phillips and removed the subwoofer.
regards
XRK
Now I now why you close wth x, that is also whe get a kiss in a letter.
anyway, the port of the BR is in throat? because I do get confused sometimes with akabak, why reverse data, oke, I have do change the BR ports to cm by change it to
*0.01 it is more easy for me.
I did see port is quite long why mine in little box is just 5.1 cm wide and 4.7 cm long, do give peak in akabak when do it in horn.
PS you do use two separate chambers for the woofers, can I chnage that to one chamber? I think it is more easy to get the horn nice looking.
I have bought paint transparant who is used for yacht this stuff is really nice stuff get things smooth.
Oke, thanks
kees
Now I now why you close wth x, that is also whe get a kiss in a letter.
anyway, the port of the BR is in throat? because I do get confused sometimes with akabak, why reverse data, oke, I have do change the BR ports to cm by change it to
*0.01 it is more easy for me.
I did see port is quite long why mine in little box is just 5.1 cm wide and 4.7 cm long, do give peak in akabak when do it in horn.
PS you do use two separate chambers for the woofers, can I chnage that to one chamber? I think it is more easy to get the horn nice looking.
I have bought paint transparant who is used for yacht this stuff is really nice stuff get things smooth.
Oke, thanks
kees
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