The dome midrange thread

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#44
The 75MX41 is the same as the D7608-9200.

The Tangband 75-1558 came in 2 versions. The first (better) version is discontinued. The new SH version is not as good IMO. It has some issues in the lower midrange which appear to be stored energy problems and lack of dampening. The dome is also very convex shaped, which causes other issues off axis, not so much an issue with more shallow domes.
 
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#46
profiguy said:
Concerning the sensitivity figures, you have to remember that a mid driver with lower efficiency can compliment a higher sensitivity system simply due to lower level FR overlap of the LF and HF drivers adding to the total midband energy. This let's a mid with a few less dB sensitivity combine to produce flat FR
Click to expand...
Indeed, and even with 280Hz - 2300Hz cross over points on my 3 way below (not a dome mid, here), shallow slopes further contribute to that, leading to seaming-less blending of drivers too, IMO.
I guess shallow HF slope on a mid dome is rather difficult?
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#50
@Radian To clean your domes, simply use some blue painters tape and GENTLY dab the sticky side without applying pressure to the dome surface and it will lift the dust particles off. As long as you use the higher quality tape and don't push down on the dome with force, it will clean them like new. I do this to all my domes and coated speaker cones. It works beautifully. It even works on domes which are pushed in if you apply very light pressure.
 
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#53
This is some unknown dome - old Peerless 2" OEM, I think were under Peerless and Philips brands many years ago. Nothing too special about them, basic motor, rear chamber with some felt stuff in it. Chamber is plastic with an audible "ting" to it with a tap test, could benefit from some reinforcement or something like dynamat stuck to the back of it. Chamber could maybe benefit from some more stuff in the pole piece too.


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Measured in a bookshelf size speaker for testing.
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Measured 0-90 at 15 deg steps.
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IB estimation by dividing on-axis mreaurement by diffraction simulation.
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Distortion measured at 2.8V. Nothing to write home about, 3rd order is high, outperformed by most cone drivers made today.
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Again, at 5V (+5dB)
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Impedance:
impedance.png
 
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#54
motokok said:
Is this the L22 @Zvu? What kind of filtering do you use? Seems like a good match to a dome mid, but I always wondered about the low sensitivity.
Click to expand...
Is this for me? It's the L18 - the L22 is in my avatar pic. I use the L18 in preference as it's a small room. XO doesn't need to be complex, other than a notch for the L18 and some minor deviation to help damp the resonance of the EM1308.
XO is below.
XO1.jpg
XO2.jpg
XO3.jpg
 
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#58
@DcibeL Yes, thats a Peerless dome. They came with extended back chamhers too.The H3 peak is due to breakup and lack of dampening in the pole cavity. If you fill that cavity with loose wool, the H3 will come down a bit, but I don't think it's that bad, especially compared to other cone drivers operating in the midband above their breakup point.
 
#60
I’ve seen some experiment with 2” compression drivers installed flipped and without a backside, using the membrane as a dome and plugging the ordinary horn throat.

Does anyone got any positive results with this setup? I’m having a couple of DAS K-8 with 4” aluminium membranes I’m thinking of trying this with.

Pretty easy to just setup and measure. I’ll post the result here if anyone is interested.
 
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