Thanks! I like it too. 
Did not change anything when switching from MTM to TMM. It measured exactly the same in my listening position.... no need to change anything.
Going from three to four woofers required some adjustment to room EQ, and of course lowering the level by 2.5 dB.
The four woofers are connected two and two in parallell, and driven with two amps.
Did not change anything when switching from MTM to TMM. It measured exactly the same in my listening position.... no need to change anything.
Going from three to four woofers required some adjustment to room EQ, and of course lowering the level by 2.5 dB.
The four woofers are connected two and two in parallell, and driven with two amps.
You'll need quite a solid tube for the new stacked subs then – and better some sort of serious exclusion zone around !
Remember, my repair kit is on the shelf, awaiting your call at anytime
An other update...... now there's four 8" woofers.
New and taller frame as well, and all drivers suspended with rubber straps.
Beautiful rig, indeed - nice proportions too!
– seems you have kind of unlimited recourses – Aladin and the wonder lamp at wintering grounds ????
How is it going with the cloth grills so far?
Michael
Last edited:
I imagine the felt mounted from frame to edge of driver chassis, and just straight up
Attachments
Think I see what you mean. That could have some effect around the tweeter and maybe be 5" mids, but not the 8" woofers. The 45 mm wide posts would not be acoustically visible for the woofers, since they are much smaller than the wavelength of the highest frequency played by the woofers (500 Hz -> wavelength 680 mm).
An other update...... now there's four 8" woofers.
New and taller frame as well, and all drivers suspended with rubber straps.
An externally hosted image should be here but it was not working when we last tested it.
Hmmmm...... never thought BDSM could be applied to DIY audio.
Last edited:
You like curves dont you?
We'll start with a tweeter polar response. The measurements are taken at the following angles: 0 - 15 - 30 - 45 - 60 - 75 - 90, distance 1 meter, anechoic MLS measurement smoothed 1/6 oct. Not bad, but there is "something" around 6 kHz. Its not the frame posts, I think its diffraction around the tweeter itself. Will investigate this.
The next is the same measurements for the midranges. There a dip around 1.5 kHz is all of them - its just me trying too hard to suppress the dipole peak. I've changed this after this measurement.
All measurements are done with EQ and XO filters, as you probably understand.
We'll start with a tweeter polar response. The measurements are taken at the following angles: 0 - 15 - 30 - 45 - 60 - 75 - 90, distance 1 meter, anechoic MLS measurement smoothed 1/6 oct. Not bad, but there is "something" around 6 kHz. Its not the frame posts, I think its diffraction around the tweeter itself. Will investigate this.
An externally hosted image should be here but it was not working when we last tested it.
The next is the same measurements for the midranges. There a dip around 1.5 kHz is all of them - its just me trying too hard to suppress the dipole peak. I've changed this after this measurement.
An externally hosted image should be here but it was not working when we last tested it.
All measurements are done with EQ and XO filters, as you probably understand.
Last edited:
The next are two measurements of the main 3-way dipole in listening position. There is one anechoic and one with 20 ms time gap. Both are MLS measurements.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And here's my revised XO and EQ curves:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
It's at the frequency, where the wave from the backside of the AMT is arriving at the ear 360° out of phase with the wave from the front - if you sit on axis (the first dipole null of the baffle). This is no fixed frequency. It varies around the perimeter of the AMT. But you can't do nothing about it except shrinking the Mundorf to half its size IMHO.
Above 6 kHz radiation changes from CD to beaming. You can see it in the diagram.
Explanation.
It is great fun indeed to see how dipole DIY has evolved in the last years and what can be achieved by braking some old rules and conventions. Especially if you have the option to choose from the best material available - like StigErik
The result is really sexy - in a special way.
Indeed. I didn't want to critizise the polars in any way - just trying to keep StigErik from investigating/investing in things that possibly can't be changed.
Rudolf