These used to be the measurement conditions. Note the date (2004) and take this with a grain of salt. It might be helpful or not. Attached is the picture of the test box in question at the time
SEAS FABRIKKER AS
15.11.2004
The files in the sub-folders are frequency response and impedance data stored in .txt files.
The data is tabulator separated and listed in the following order:
Frequency Magnitude Phase
These measurements are made in a box that can be used as a 2-way speaker. It is important that you note this difference if you compare these measurements to the datasheets for our drivers. The boundry conditions are different, especially on the tweeter measurements, so here you will see diffraction effects.
The object of this project is to give our customers access to measured data that can be used to simulate a crossover. While using LspCAD for some time I have found a very good correlation between simulated and measured end-result, so I hope this will make it easier for you to construct your own speaker.
Measurement conditions
The speaker is placed on a turntable-stand in a 4-pi (free-field) anechoic chamber.
Applied voltage is 2.83 volts. Measurement system is ATB precision. All measurements are done with a stepped sine at 250 frequency points. No gating. Smoothing at 1 (lowest setting- approx. 1/12 oct.)
The microphone (B&K 4133) was placed 1 meter from the front of the speaker, on the tweeter axis. The microphone was not moved during the whole measurement session. The woofer measurements are also done with the microphone centered on the tweeter axis. The reason for doing this is that the relative phase difference between woofer and tweeter will be accurately stored in the measurements.
To verify your simulation setup you can do the following (I'm referring to LspCAD):
Go to the General menu and import the following file in the "Target SPL curve"
L18RNX_P & 27TFFC in paralell-SPL.txt
This file shows a measurement from 100Hz to 20kHz with a woofer and tweeter in paralell without any crossover components attached.
Set the measurement distance to 1 meter.
Then import the IMP and SPL_on axis files for the same drivers located in it's respective sub folder.
L18RNX_P H1224-08_IMP.txt
L18RNX_P H1224-08_SPL_on axis.txt
27TFFC H881-06_IMP.txt
27TFFC H881-06_SPL_on axis.txt
The simulated sum of these two drivers without any crossover components and connected in paralell should match the "Target SPL curve" above 100Hz.
Off-axis measurments is also included in the folders. To get a reliable result in simulation you should always import both woofer and tweeter files for the same angle. Again, this is to get the phase difference correct. All off-axis measurements are in the horisontal-plane. Now you have a chance to see both effects of driver directivity and diffraction in your simulation of an off-axis response.
Box
The box outside dimensions:
Front baffle: 20cm wide and 49.6cm high
Box depth: 29.6cm
Edges are trimmed with a roundover-bit r=12mm.
Driver placement:
Both drivers are centered on the vertical axis.
The distance between the drivers centers are 158.5mm
The distance from the top of the baffle to the tweeter centre: 65mm
The distance from the top of the baffle to the woofer centre: 223.5mm
The box has a removable tweeter baffle. This way we can measure all drivers flush mounted in the same box.
The box is approximately 18 liters and the port tuning is approximately 40Hz. All woofers are measured like this, regardless of what the T/S calculations suggest.
Good luck with your speaker building.
Remember to check that the drivers are available at your local distributor.
Bjorn Magne Idland
Lab technician
Seas Fabrikker AS
bidland@seas.no
041112
SEAS FABRIKKER AS
15.11.2004
The files in the sub-folders are frequency response and impedance data stored in .txt files.
The data is tabulator separated and listed in the following order:
Frequency Magnitude Phase
These measurements are made in a box that can be used as a 2-way speaker. It is important that you note this difference if you compare these measurements to the datasheets for our drivers. The boundry conditions are different, especially on the tweeter measurements, so here you will see diffraction effects.
The object of this project is to give our customers access to measured data that can be used to simulate a crossover. While using LspCAD for some time I have found a very good correlation between simulated and measured end-result, so I hope this will make it easier for you to construct your own speaker.
Measurement conditions
The speaker is placed on a turntable-stand in a 4-pi (free-field) anechoic chamber.
Applied voltage is 2.83 volts. Measurement system is ATB precision. All measurements are done with a stepped sine at 250 frequency points. No gating. Smoothing at 1 (lowest setting- approx. 1/12 oct.)
The microphone (B&K 4133) was placed 1 meter from the front of the speaker, on the tweeter axis. The microphone was not moved during the whole measurement session. The woofer measurements are also done with the microphone centered on the tweeter axis. The reason for doing this is that the relative phase difference between woofer and tweeter will be accurately stored in the measurements.
To verify your simulation setup you can do the following (I'm referring to LspCAD):
Go to the General menu and import the following file in the "Target SPL curve"
L18RNX_P & 27TFFC in paralell-SPL.txt
This file shows a measurement from 100Hz to 20kHz with a woofer and tweeter in paralell without any crossover components attached.
Set the measurement distance to 1 meter.
Then import the IMP and SPL_on axis files for the same drivers located in it's respective sub folder.
L18RNX_P H1224-08_IMP.txt
L18RNX_P H1224-08_SPL_on axis.txt
27TFFC H881-06_IMP.txt
27TFFC H881-06_SPL_on axis.txt
The simulated sum of these two drivers without any crossover components and connected in paralell should match the "Target SPL curve" above 100Hz.
Off-axis measurments is also included in the folders. To get a reliable result in simulation you should always import both woofer and tweeter files for the same angle. Again, this is to get the phase difference correct. All off-axis measurements are in the horisontal-plane. Now you have a chance to see both effects of driver directivity and diffraction in your simulation of an off-axis response.
Box
The box outside dimensions:
Front baffle: 20cm wide and 49.6cm high
Box depth: 29.6cm
Edges are trimmed with a roundover-bit r=12mm.
Driver placement:
Both drivers are centered on the vertical axis.
The distance between the drivers centers are 158.5mm
The distance from the top of the baffle to the tweeter centre: 65mm
The distance from the top of the baffle to the woofer centre: 223.5mm
The box has a removable tweeter baffle. This way we can measure all drivers flush mounted in the same box.
The box is approximately 18 liters and the port tuning is approximately 40Hz. All woofers are measured like this, regardless of what the T/S calculations suggest.
Good luck with your speaker building.
Remember to check that the drivers are available at your local distributor.
Bjorn Magne Idland
Lab technician
Seas Fabrikker AS
bidland@seas.no
041112
Attachments
Today's Polish measurement of L19RNX1 (17l closed box):
Takie Tam i inne ciekawostki od Zap Projekt ów
Takie Tam i inne ciekawostki od Zap Projekt ów
Vance Dickason tested the L19RNX1 too: Test Bench: The SEAS L19RNX1 Prestige Titan Series Woofer | audioXpress
Currently I'm building construction whit 2x Seas L19RNX1 + Satori TexTreme MW16TX-4 + Bliesma T25B. I plan closed box for Seas.
url=https://diyaudio.pl/i/28708/e2be328da44b7baf3b09bea48e4e0572_1624350885.jpg]
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url=https://diyaudio.pl/i/28708/e2be328da44b7baf3b09bea48e4e0572_1624350885.jpg]
Are those your pictures? That looks really nice! How is the project coming along?
Thanks 🙂
They are picture of my project. Now I'm waiting for felt "star".
My friend will be doing measurements and simulations crossover.
And the second - 2xSatori MW19P + Scan Speak 18M + Audax TW025A28 (Bliesma only for fotos)
They are picture of my project. Now I'm waiting for felt "star".
My friend will be doing measurements and simulations crossover.
An externally hosted image should be here but it was not working when we last tested it.
And the second - 2xSatori MW19P + Scan Speak 18M + Audax TW025A28 (Bliesma only for fotos)
An externally hosted image should be here but it was not working when we last tested it.
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