Hi to all
I'm a little bit confused on how to proceed and make measurements with Umik-1 and rew on my open baffle speaker. I have a minidsp that i want to use for testing and then build the analog crossover network from Nelson Pass with the adjustments and corrections discovered with the help of Minidsp and Umik-1
I know how to measure and use the software/hardware but need guidance on how to do it. In room measurements, near field? Measure each driver first and then the complete speaker? What to correct first? the frequency response with near field measurements on each driver, or what?
The open baffle speaker is a pure audio clone with 2 eminence beta15 per channel and a Markaudio 10.3 for the fullrange in the middle of them.
Thanks in advance.
I'm a little bit confused on how to proceed and make measurements with Umik-1 and rew on my open baffle speaker. I have a minidsp that i want to use for testing and then build the analog crossover network from Nelson Pass with the adjustments and corrections discovered with the help of Minidsp and Umik-1
I know how to measure and use the software/hardware but need guidance on how to do it. In room measurements, near field? Measure each driver first and then the complete speaker? What to correct first? the frequency response with near field measurements on each driver, or what?
The open baffle speaker is a pure audio clone with 2 eminence beta15 per channel and a Markaudio 10.3 for the fullrange in the middle of them.
Thanks in advance.
An excellent reading about the design of loudspeakers written by a legend.
But you want to design your own loudspeaker
But you want to design your own loudspeaker
Thank you.
Siegfried doesnt measure in room nor nearfield. Only free field. I understand the role of "brain" in this context. I am (was) a professional pianist and have studied music and its subjects all my life. I dont want the ideal speaker because i am sure that doenst exist. However, i need some balance between subjective perception and absolute readings or measurements.
Siegfried doesnt measure in room nor nearfield. Only free field. I understand the role of "brain" in this context. I am (was) a professional pianist and have studied music and its subjects all my life. I dont want the ideal speaker because i am sure that doenst exist. However, i need some balance between subjective perception and absolute readings or measurements.
From my experience, I would recommend to use two kind of measurements:
1) Ground plane measurements for the low frequencies and
2) In-room gated measurements for the higher frequencies
Subjective perception could be very confusing for a loudspeaker design.
1) Ground plane measurements for the low frequencies and
2) In-room gated measurements for the higher frequencies
Subjective perception could be very confusing for a loudspeaker design.
can you explain how to put the mic in the ground plane measurements?
The in room measurements i think we must put the mic at the listening position pointing between the two speakers. is it?
Thanks
The in room measurements i think we must put the mic at the listening position pointing between the two speakers. is it?
Thanks
Ground-plane measurement needs a large space, clear from other objects.
Usually it is performed outdoors or in very large rooms.
Some good examples for ground plane measurements are here:
HiFi Loudspeaker Design
Ground Plane Measurements for optimiziing an loudspeaker
For the gated measurements look here:
Loudspeaker measurements
regards
George
Usually it is performed outdoors or in very large rooms.
Some good examples for ground plane measurements are here:
HiFi Loudspeaker Design
Ground Plane Measurements for optimiziing an loudspeaker
For the gated measurements look here:
Loudspeaker measurements
regards
George
Bom Dia Joca,
Dipole speakers are a little bit difficult to measure, and I´m absolutely no specialist in that.
I might, however, suggest a simple start for your measuring adventures:
- Rig up the speakers in the room, like you want them when listening to music: symmetrical to the room, away from walls etc.
- Rig up the microphone near to your listening position. Your measurements will include all sorts of room effects, but a) that´s how a dipole works and b) that´s what you´ll be going to hear in the end.
- Measure the bass drivers, adjust bass filter, try to get them even between, let´s say 40Hz and 300Hz, and let them drop considerably after that, as there will be audible mid resonances in the drivers. Work with the filter configurations like later possible in the Pass design. The bass won´t be flat.
- Same with the FR driver from 300 or so to 16000. Adjust filter.
- Measure both drivers together and adjust delay etc. to get the CO area right.
- Measure left/right and integrate.
- Measure many variable positions and integrate, in order to get an idea of the room response.
- When everything looks halfway ok, start listening and fine adjust the filter by ear. That will take a lot longer and is more important than to have a perfectly flat measuring speaker or a dB more or less here and there...
Now, this is all not very sophisticated, and I may be corrected, but I believe will make for a viable start. Good luck!
Cumprimentos
Mattes
Dipole speakers are a little bit difficult to measure, and I´m absolutely no specialist in that.
I might, however, suggest a simple start for your measuring adventures:
- Rig up the speakers in the room, like you want them when listening to music: symmetrical to the room, away from walls etc.
- Rig up the microphone near to your listening position. Your measurements will include all sorts of room effects, but a) that´s how a dipole works and b) that´s what you´ll be going to hear in the end.
- Measure the bass drivers, adjust bass filter, try to get them even between, let´s say 40Hz and 300Hz, and let them drop considerably after that, as there will be audible mid resonances in the drivers. Work with the filter configurations like later possible in the Pass design. The bass won´t be flat.
- Same with the FR driver from 300 or so to 16000. Adjust filter.
- Measure both drivers together and adjust delay etc. to get the CO area right.
- Measure left/right and integrate.
- Measure many variable positions and integrate, in order to get an idea of the room response.
- When everything looks halfway ok, start listening and fine adjust the filter by ear. That will take a lot longer and is more important than to have a perfectly flat measuring speaker or a dB more or less here and there...
Now, this is all not very sophisticated, and I may be corrected, but I believe will make for a viable start. Good luck!
Cumprimentos
Mattes
You will have the exact same problems as when you are measuring a loudspeaker in a box. You can't get accurate LF measurements indoors. You can still do a nearfield measurement, but that will only capture ONE SIDE of the driver output. If you do another nearfield measurement at the back, you can combine the two into the LF dipole response using the method I describe here:
3-way open baffle plus subs
I do it all the time.
Just like with a boxed speaker, you will need to combine the synthesized LF data with higher frequency data above the frequency where it becomes valid (e.g. if/when you are using a gated measurement). If your crossover points happen to fall around that frequency, there is not a need to merge the data.
3-way open baffle plus subs
I do it all the time.
Just like with a boxed speaker, you will need to combine the synthesized LF data with higher frequency data above the frequency where it becomes valid (e.g. if/when you are using a gated measurement). If your crossover points happen to fall around that frequency, there is not a need to merge the data.
Good approach but it assumes that front and rear radiation are identical, which we know is not true above some frequency where the basket and magnet structure start to cause interference, the cone is a different "shape" when viewed from front and back, etc. Also, not strictly valid for U-frame or other asymmetrical low frequency dipoles.
With all of those caveats, if you believe you have symmetrical front and rear radiation this is a great way to derive the dipole response.
Otherwise, simply measure the rear nearfield instead of using the front data as I described in the link in my last post, above.
I just measure nearfield at 0.5m and at least 1m above floor or below ceiling, and use 6 cycle frequency dependent windo (FDW) function in REW to filter out room reflections. This lets you measure the intrinsic behavior of the speaker. Below 400Hz or so, there are box and room effects but you will get a good idea. The bass response really can't be measured accurately unless you are in an open area with no walls or floor. Or an anechoic chamber - just don't worry about the bass too much. At 0.5m and 6 cycle FDW you get a pretty good idea if your bass extends deep enough and how your room gain plays into it.