I should clarify I don't have a TV in my HT room - cum speaker lab/studio. We have a couple upstairs. Between work and foam core speakers there is barely time to sleep let alone watch TV. Although I make special provision for game of thrones. 🙂
😛
IG
Funny, and definitely at least partly true.
For myself, I've never felt exactly smug about it. Since I left home in 1979, I've never owned a TV, sometimes by choice, sometimes by income. While I sometimes watch (and even LIKE!) TV, I do feel STRONGLY that TV has the POTENTIAL to be bad news for kids...
Of course, if I could build a DIY FC TV with my kids, I'd be all over it...😀
OT but TV's destructive force is greatly mitigated if you don't watch broadcast, with commercials etc. We've always had TVs but limit the screen time and don't watch cable/broadcast etc. Just movies on hard media/netflix streaming.
Nothing more than good old 2.0 via built in headphone out jack. I need to get a multichannel sound card - I hear that one can do all the DSP crossover and filters in the PC. Or get a miniDSP.
Asus Xonar Essence ST soundcard is not a bad start and with an add on card it can be multi channel...
Teardrop Build Begins
So it begins... all these teardrop/eggshape enclosures have got me interested in making a neat sealed enclosure that minimizes back wave reflections. I made some gore panels hoping for a 7 sided unit but as I am gluing it, it looks like no more than 6 will end up fitting. 🙁 (7 to prevent parallel wall resonance). Here is what I have so far. I must say this goes very quickly and is quite easy with foam core. Amazing what one can accomplish between morning coffee and leaving for the day. 🙂
So it begins... all these teardrop/eggshape enclosures have got me interested in making a neat sealed enclosure that minimizes back wave reflections. I made some gore panels hoping for a 7 sided unit but as I am gluing it, it looks like no more than 6 will end up fitting. 🙁 (7 to prevent parallel wall resonance). Here is what I have so far. I must say this goes very quickly and is quite easy with foam core. Amazing what one can accomplish between morning coffee and leaving for the day. 🙂
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Thanks Wesayso.
Yes, I have looked at this and it looks nice. It may end up more than a miniDSP but you get more channels.
Thanks Carl 🙂
Figuring out how to internally brace this is tricky.
Having fun and almost running out of FC again.
Figuring out how to internally brace this is tricky.
Having fun and almost running out of FC again.
Teardrop Build Completed
The Tear Drop foam core speaker is now completed. The build was a lot of fun and demonstrates the ability of FC to form smooth complex curves with an inflection (concave on both sides at different points). I was able to fit my hand and glue gun inside the cavity once the cap was cut off in order to glue the 3 internal braces which form a 6-pointed star spider. Even without the brace, the structure was very rigid. I filled it with denser stuffing in the tail and progressively going to very light stuffing in the main cavity and the front 1/3 without any stuffing. Added some 24 ga Cat5 wiring with crimp terminals, and away we go...
How does it sound? Very nice, similar to the Nautaloss and very transparent, in that the speaker disappears as there are no hard edges for diffraction.
A very cool speaker for the FC builder with some more advanced curve-forming skills. About 4 hrs total build time.
This speaker can benefit from a driver with a round bezel. 🙂
Measurements next...
The Tear Drop foam core speaker is now completed. The build was a lot of fun and demonstrates the ability of FC to form smooth complex curves with an inflection (concave on both sides at different points). I was able to fit my hand and glue gun inside the cavity once the cap was cut off in order to glue the 3 internal braces which form a 6-pointed star spider. Even without the brace, the structure was very rigid. I filled it with denser stuffing in the tail and progressively going to very light stuffing in the main cavity and the front 1/3 without any stuffing. Added some 24 ga Cat5 wiring with crimp terminals, and away we go...
How does it sound? Very nice, similar to the Nautaloss and very transparent, in that the speaker disappears as there are no hard edges for diffraction.
A very cool speaker for the FC builder with some more advanced curve-forming skills. About 4 hrs total build time.
This speaker can benefit from a driver with a round bezel. 🙂
Measurements next...
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Measurements of Tear Drop and Nautaloss
After realizing that I was measuring room effects which caused a drop-off at 300 Hz, I was more careful with arranging the setup this time. I skewed the speaker axis 45 deg to room walls, added a sheet of 2 in thick open cell foam on the floor beneath speaker and mic. Put a pillow underneath the mic tripod, and draped a loose blanket over the tripod legs. Note that my measurement only goes up to about 5-6 kHz as the laptop soundcard has a low pass filter.
The measurements were made at a height of approximately 35 to 39 in high off the floor and 4 in away from speaker cone.
The "room treatments" were amazing in that the 300 Hz drop off immediately disappeared and the bass extension goes to the approx 150 Hz that was predicted by the model for the Nautaloss. Here are the measurements of the Nautaloss with the room treatments (green) compared with the old (red) and compared with the Tear Drop (blue).
Both speakers performed quite well with the Nautaloss getting the edge in flatness of frequency response in the higher registers.
Here is the Nautaloss measurement with THD and Phase also shown:
Here is the Tear Drop measurement with THD and Phase:
The THD figure of -50 dB from 200 Hz on up is quite amazing. The Nautaloss also gets the nod for the impulse response as the Tear Drop, although very good, has a slightly higher secondary negative peak.
I think that either of these would be excellent choices for near-field critical listening as monitors above 200 Hz.
After realizing that I was measuring room effects which caused a drop-off at 300 Hz, I was more careful with arranging the setup this time. I skewed the speaker axis 45 deg to room walls, added a sheet of 2 in thick open cell foam on the floor beneath speaker and mic. Put a pillow underneath the mic tripod, and draped a loose blanket over the tripod legs. Note that my measurement only goes up to about 5-6 kHz as the laptop soundcard has a low pass filter.
The measurements were made at a height of approximately 35 to 39 in high off the floor and 4 in away from speaker cone.
The "room treatments" were amazing in that the 300 Hz drop off immediately disappeared and the bass extension goes to the approx 150 Hz that was predicted by the model for the Nautaloss. Here are the measurements of the Nautaloss with the room treatments (green) compared with the old (red) and compared with the Tear Drop (blue).
Both speakers performed quite well with the Nautaloss getting the edge in flatness of frequency response in the higher registers.
Here is the Nautaloss measurement with THD and Phase also shown:
Here is the Tear Drop measurement with THD and Phase:
The THD figure of -50 dB from 200 Hz on up is quite amazing. The Nautaloss also gets the nod for the impulse response as the Tear Drop, although very good, has a slightly higher secondary negative peak.
I think that either of these would be excellent choices for near-field critical listening as monitors above 200 Hz.
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Hi xrk971,
This is all very neat 🙂. Have you tried to use your Nautalos as a BLH w/ the driver (or drivers) mounted in the center? Also, you can add your tractrix horn pointed sideways.
Regards,
This is all very neat 🙂. Have you tried to use your Nautalos as a BLH w/ the driver (or drivers) mounted in the center? Also, you can add your tractrix horn pointed sideways.
Regards,
Well that becomes a Cornu BLH. I have not specifically tried the 36 in long Nautaloss spiral as a BLH. It would not produce very deep bass at 150 Hz.
The spiral Nautaloss is good enough for me to commence with the stereo pair for the first unit. In progress...