Hi Solve, glad you like it.
Are you sure yoú used enough damping material ? It is pretty well damped. 100g is a high density for this small volume. I use 200g in my TL sub, which is s much bigger cabinet with a 10" driver.
I have not experienced boomy sound, but I sure did when I tried it with Hi-Vi 3".
Hi from Bjorn
Are you sure yoú used enough damping material ? It is pretty well damped. 100g is a high density for this small volume. I use 200g in my TL sub, which is s much bigger cabinet with a 10" driver.
I have not experienced boomy sound, but I sure did when I tried it with Hi-Vi 3".
Hi from Bjorn
alternative design
Hi guys!
I've recently built a designed and built a similar speaker for newer TB 3" - W3-1231SH. It was also designed using MJK's worksheets (a little older version). It is a MLTL, built from 1/2" MDF. Front, back and side pieces are 3" wide and 18.5" long. Top and bottom are 3" x 4" and glued on top of the sides. So, the inside dims are 2"x3"x18.5", and external 3"x4"x19.5".
The driver is 6" from the top inside. The port center is 9.5" from the top inside. Port ID is 0.82". The length is 2".
The speakers are designed to actually hang on the wall. I will try to attach the MJK's simulation, the actual Sound Easy measurements, done on the wall and a picture. Not sure if it can be done in one post. If not, I'll put the rest in separate posts.
VadimB
Hi guys!
I've recently built a designed and built a similar speaker for newer TB 3" - W3-1231SH. It was also designed using MJK's worksheets (a little older version). It is a MLTL, built from 1/2" MDF. Front, back and side pieces are 3" wide and 18.5" long. Top and bottom are 3" x 4" and glued on top of the sides. So, the inside dims are 2"x3"x18.5", and external 3"x4"x19.5".
The driver is 6" from the top inside. The port center is 9.5" from the top inside. Port ID is 0.82". The length is 2".
The speakers are designed to actually hang on the wall. I will try to attach the MJK's simulation, the actual Sound Easy measurements, done on the wall and a picture. Not sure if it can be done in one post. If not, I'll put the rest in separate posts.
VadimB
alternative design
Sorry,
I could not figure out the way to shrink my pictures to the required 100x100 size, so lets try this:
VadimB
Sorry,
I could not figure out the way to shrink my pictures to the required 100x100 size, so lets try this:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
VadimB
I got my W4-1320SA and smacked them in.
What could i say?
Woooaahhh!
There the bottom comes that i want!!
Sounds very good!
Solve
What could i say?
Woooaahhh!
There the bottom comes that i want!!
Sounds very good!
Solve
First of all, i dont have much experiance of measuring speakers
but i did an very basic try.
Im using an uncalibrated Panasonic WM-61A with my computer
and an StValue 24bit soundcard(Envy24 chip).
Software Tombstone running an sweep 20-20khz with
W4-1320SAwith BSC 0,8mH+3,9ohm.
First one is with modded T-amp.
Red line is port.
but i did an very basic try.
Im using an uncalibrated Panasonic WM-61A with my computer
and an StValue 24bit soundcard(Envy24 chip).
Software Tombstone running an sweep 20-20khz with
W4-1320SAwith BSC 0,8mH+3,9ohm.
First one is with modded T-amp.
Red line is port.
Attachments
Measurements
Solve,
In your first measurement with T-amp, there is a message at the left bottom corner of the screen: "Input overloaded". That's, probably, what is responsible for a ruller-flat curve at 0dB. Your later data do not have this message, so they are much more realistic. If the first one was a near-field measurement, just lower the volume until the curve is lower than 0dB and has some wiggles. You can only trust near-field up to, maybe, 1kHz at the most. Also, if you want to add this data to the port output, do not forget to scale the port data by the ratio of port diamenter to driver diameter squared. Than you can splice that to the 1 meter data. Still, this will not account for difraction effects (baffle step).
The single best book on how to measure speakers properly is Joe DiAppolito's "Testing Loudspeakers", available from Audio Express.
VadimB
Solve,
In your first measurement with T-amp, there is a message at the left bottom corner of the screen: "Input overloaded". That's, probably, what is responsible for a ruller-flat curve at 0dB. Your later data do not have this message, so they are much more realistic. If the first one was a near-field measurement, just lower the volume until the curve is lower than 0dB and has some wiggles. You can only trust near-field up to, maybe, 1kHz at the most. Also, if you want to add this data to the port output, do not forget to scale the port data by the ratio of port diamenter to driver diameter squared. Than you can splice that to the 1 meter data. Still, this will not account for difraction effects (baffle step).
The single best book on how to measure speakers properly is Joe DiAppolito's "Testing Loudspeakers", available from Audio Express.
VadimB
You have an good eye VadimB!
Didnt see that.In tombstone you get an pop up screen that say the same so i trusted that...
But you are right, it was to good!
Now we see that ugly 7khz peak.
How do i notch that?
"Also, if you want to add this data to the port output, do not forget to scale the port data by the ratio of port diamenter to driver diameter squared."
How do i do that?
Now i just moved the mic without changing the volume.
Think i have to get that book.
Solve
Didnt see that.In tombstone you get an pop up screen that say the same so i trusted that...
But you are right, it was to good!
Now we see that ugly 7khz peak.
How do i notch that?
"Also, if you want to add this data to the port output, do not forget to scale the port data by the ratio of port diamenter to driver diameter squared."
How do i do that?
Now i just moved the mic without changing the volume.
Think i have to get that book.
Solve
Attachments
Assuming both port and driver are measured near filed, AT THE SAME LEVEL, your data show relative sound pressure at the microphone. Your Panasonic mic is very small, so it does not take into accound that driver has larger radiating area.
The overall SPL (sound pressure level) is proportional to the radiating area of the source. I guess the port is smaller than the driver. Than you have to lower the measured curve from the port by Delta=10*log(D port / D driver)^2 dB.
For example, say the effective diameter of your 4" TB is 3.5" and the ID of the port is 1.5".
Delta = 10*log(1.5*1.5/3.5*3.5)=-7.35 dB.
As soon as I wrote this, I started to doubt myself: do we have to multiply by 10 or by 20 here? I would appreciate a correction, if my memory failed me.
In any case, another good way of checking it is that at very low frequencies, say below 20 Hz the curves should coinside.
Important thing is that you should make these measurements as close as possible to the cone and the terminus of the port (no more than 5mm), and do not change the volume between the two measurements.
VadimB
"Important thing is that you should make these measurements as close as possible to the cone and the terminus of the port (no more than 5mm), and do not change the volume between the two measurements."
I did.
But then its mathematics for the pro...
Now i know why i need that!
Keep going VadimB!
But dont brag for us stupid.
🙂
Learn us with example.
Solve
I did.
But then its mathematics for the pro...
Now i know why i need that!
Keep going VadimB!
But dont brag for us stupid.
🙂
Learn us with example.
Solve
Solve,
I actually need your help to do just that. Earlier in this thread, I've posted an alternative design for 3" TB driver and promised to post measurements. I have screen shots from Sound Easy for that speaker, however they are large files with higer resoultuion. No matter what I do, the software of this Forum tells me that "attached file is too large".
Can you, please, teach me how to do this?
VadimB
P.S. If there will be some interest in that design - I'll start a new thread on it.
Sorry! That user has specified that they do not wish to receive emails through this board. If you still wish to send an email to this user, please contact the administrator and they may be able to help.
?
I help you when you fix it.
🙂
Solve
Sorry for this mumbo jumbo.
?
I help you when you fix it.
🙂
Solve
Sorry for this mumbo jumbo.
VadimB i cant email you?
Sorry for this folks...
Sorry! That user has specified that they do not wish to receive emails through this board. If you still wish to send an email to this user, please contact the administrator and they may be able to help.
Solve
Sorry for this folks...
Sorry! That user has specified that they do not wish to receive emails through this board. If you still wish to send an email to this user, please contact the administrator and they may be able to help.
Solve
Sorry for OT
Solve,
I've just openned all the doors there are on the "options" tab of my prophile. If this does not work, I'll have to contact the administrator. I've sent an e-mail to the address you gave (*.hotmail) last week. Did you get that?
Sorry for the bandwidth, folks!
VadimB
Solve,
I've just openned all the doors there are on the "options" tab of my prophile. If this does not work, I'll have to contact the administrator. I've sent an e-mail to the address you gave (*.hotmail) last week. Did you get that?
Sorry for the bandwidth, folks!
VadimB
Didnt get it.
Maybe an dot to much.
peter_fors(@)hotmail.com
Solve
(Sorry for this-have enough of spam)
Maybe an dot to much.
peter_fors(@)hotmail.com
Solve
(Sorry for this-have enough of spam)
Correction
Folks,
I've finally checked the DiAppolito book and, man, was I wrong!
The correct formula for correction of port-to-woofer is:
Delta (dB) = 20*log(D port / D woofer)
Diameters are not squared!
So, in the previous example (woofer 3.5", port 1.5"), the correction is:
Delta = 20*log(1.5/3.5) = -7.34 dB,
so the port near-field response should be lowered by 7.34 dB and then summed with the woofer.
Sorry, but it's better late than never...
VadimB
Folks,
I've finally checked the DiAppolito book and, man, was I wrong!
The correct formula for correction of port-to-woofer is:
Delta (dB) = 20*log(D port / D woofer)
Diameters are not squared!
So, in the previous example (woofer 3.5", port 1.5"), the correction is:
Delta = 20*log(1.5/3.5) = -7.34 dB,
so the port near-field response should be lowered by 7.34 dB and then summed with the woofer.
Sorry, but it's better late than never...
VadimB