i am building a 4 way system, the mid bass is a 27 liter closed box 12pr320, the frequency response measurement is terrible:
instead in Nearfield measurement I have this result:
the measurements I made outdoors and without crossover
what can i have wrong? Building a closed box in 18mm birch plywood is not complicated!
instead in Nearfield measurement I have this result:
the measurements I made outdoors and without crossover
what can i have wrong? Building a closed box in 18mm birch plywood is not complicated!
Did you measure inside your house on the first graph?
Have a look here and see how the low frequency response is affected by the room:
Room Simulator
Daniel
Have a look here and see how the low frequency response is affected by the room:
Room Simulator
Daniel
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I'm not a specialist, but I find it good for a little 28L and a so big 12" midbass.
The response below few hundred hertz is also about how you measured . mic & bafle on the floor, outside ? It seems bafle step free ! wide width cabinet with low deep ? 28 L is not so much, grossly30x30 bafle circa ?
The response below few hundred hertz is also about how you measured . mic & bafle on the floor, outside ? It seems bafle step free ! wide width cabinet with low deep ? 28 L is not so much, grossly30x30 bafle circa ?
The big width explain the shy if not existing baffle step of your measurement.
Did you measure the T&S of the two 12" ? 28 liters was ok in the sim related to the Vas measured ?
Maybe the 90° top of the front baffle ? What does it gives with room gain ? or driver raw outside if you can flush it in the soil and put the mic 1 metre above ? Mic and driver lying on the soil seems quite a comon method as well.
Did you measure the T&S of the two 12" ? 28 liters was ok in the sim related to the Vas measured ?
Maybe the 90° top of the front baffle ? What does it gives with room gain ? or driver raw outside if you can flush it in the soil and put the mic 1 metre above ? Mic and driver lying on the soil seems quite a comon method as well.
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I'm not looking for deep bass, it must be the midrange, for the bass there is 18 ".
I am looking for a linear frequency response
Other than the ground bounce dips at 50Hz and 120Hz, and possible off axis deviations, your 12pr320's response does not look all that different from Faital's measurements.
Try putting both the speaker and mic on the ground at 2 meters, angle the speaker so it's center is on axis to the mic.
Try putting both the speaker and mic on the ground at 2 meters, angle the speaker so it's center is on axis to the mic.
Attachments
in the range that interests me 100-1000hz faital measurements is + -3db
my measurement is + -11db
Not sure i understand the reponses you posted.
I take it the top one with 1/12th smoothing is outdoors @ 1-3m ... correct?
The bottom one though, is it nearfield outdoors?
Looks heavily gated however taken..??
What freq range are you planning to use? Honestly, response looks pretty good to me.
I take it the top one with 1/12th smoothing is outdoors @ 1-3m ... correct?
The bottom one though, is it nearfield outdoors?
Looks heavily gated however taken..??
What freq range are you planning to use? Honestly, response looks pretty good to me.
I did not understand the question
however I made various measurements, 1,2,3 mt I varied the volume but the measurement has always been the same.
I took the measurements outdoors, in the garden
I don't have a clue what "mid-bass" means or what band you want the thing tested in the first plot to cover. Seems to cover 200 to 2k just fine - but I'd like to see the THD plot too.
B.
B.
jenoux,
FaitalPRO has measured driver frequency response differently than you, so their plot does not show floor bounce. There is nothing wrong with the unit.
FaitalPRO has measured driver frequency response differently than you, so their plot does not show floor bounce. There is nothing wrong with the unit.
The deviations between close-mic'd and far-mic'd below 100Hz suggest you're still getting some reflections in there. A nearby wall would do the trick.
Apart from that, your measurements look fine to me. You're getting 100Hz-2kHz within a few dB of flat.
Chris
This is why you look at nearfield below at least 200 Hz.
Ignore the one that isn't nearfield for less than 300 Hz.
IF you have a very flat ground with no other boundaries (walls, etc.) near (at least 20 meters away) your loudspeaker, have very little background noise, and can lay the loudspeaker on its side and the mic. on the floor at 2 meters distance, only then could you achieve a better result at lower freq.s.
Your measurements were good enough for me to look up the driver for a project I'm planning 😀
Thanks,
Rob.
Thanks,
Rob.
T Gravsen uses it ported. But I don't see why it could not be used sealed with a bigger cabinet with a nicer -F10 than a ported and the help of the room gain, better group dela and often sounds better than PA drivers setuped too low vis a vis of the resonance (max lowest flat curves for instance). On the datasheet it looks to me sexier than the SB34nrx... has some neo magnet like the Eminence Deltalite ProII and is priced correctly, at least in Europe...
Now a PHL 10" if there is a 18 before.... 🙂 , well off topic ! Anyway that's a longtie I lurk on that Faital, some reported it sounds nicer than the big15 brother.
Now a PHL 10" if there is a 18 before.... 🙂 , well off topic ! Anyway that's a longtie I lurk on that Faital, some reported it sounds nicer than the big15 brother.
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