For 12" I bet it's beaming, which is directivity problem goes incoherent with main speakersI have 2 of them placed in an equilateral triangle below the mains
For 12" I bet it's beaming, which is directivity problem goes incoherent with main speakersI have 2 of them placed in an equilateral triangle below the mains
I have no science confirmation for following statement, but afaik diy community looks at combination of Mms and BL (force factor).What in the specs or measurements tell you to not use this driver at, say, 500hz?
You have chosen a good example with the Seas L26ROY.What in the specs or measurements tell you to not use this driver at, say, 500hz?
I have 2 of them placed in an equilateral triangle below the mains
Those are two different measurements
That one is listening position with crossover and Dirac, this one is at 1cm, with no filters or processing showing the response of the sub alone
Those are two different measurements
That one is listening position with crossover and Dirac, this one is at 1cm, with no filters or processing showing the response of the sub alone
Ah. so OP was correct with the model number of L26RO4Y. Man, it does look like it starts to break up around 800Hz unlike the L26ROY. The only question I have is that, if you've got a good FR, and crossover before all of the peaks and dips, wouldn't it still be competent as a mid-bass driver? I guess this is where a graph showing 1-3rd order harmonics would be helpful.You have chosen a good example with the Seas L26ROY.
This is available in two versions, the old, discontinued version (D1001-04 L26ROY) and the current one (XM004-04 L26RO4Y).
Would I use the current version in the frequency range above 150Hz?
Rather not, because the frequency response shows that the driver probably can't follow signals above 100Hz any longer correctly, the manufacturer's measurement shows a falling frequency response in half-space:
View attachment 143100
This is an indication that the magnet (and cone) is not strong enough to accelerate the high membrane mass accordingly.
Eigenmodes and break-up resonances then occur at higher frequencies.
The discontinued version showed a completely different frequency response and was more suitable for reproducing frequencies above 100 Hz:
View attachment 143101
In the new version the moving mass is 160g, in the discontinued version only 107g.
In the new version, magnet strength and diaphragm stiffness and high voice coil inductance (compare the blue arrows at the impedance curves) no longer seem sufficient for "correct" frequency reproduction above 100Hz.
You have already answered the question yourself.I have is that, if you've got a good FR, and crossover before all of the peaks and dips, wouldn't it still be competent as a mid-bass driver? I guess this is where a graph showing 1-3rd order harmonics would be helpful.
If we talk about properly designed subwoofer driver, we assume it very stiff and working pistonically.What about cone breakup?
Thats the main reason you can not do crossover higher than 100 Hz
I tried crossing several subwoofers "too high" and they all sounded very bad.
However I cannot see anything in the measurements or specs that suggests so, the FR looks flat but it still sounds terrible. it's not just beaming, it sounds "boomy" and "slow" and "muddy" in every direction.
e.g. this Seas L26RO4AY has usable FR up to 800hz per the manufacturer, and is even recommended up to 1Khz. yet it sounds really bad starting as low as 200hz.
I had the similar impression with peerless XLS12 and Dayton UM15, and saw similar impressions by other builders.
What in the specs or measurements tell you to not use this driver at, say, 500hz?
Woofers or subwoofers?