Apologies for the late reply - now that I no longer have any inclination to thinker with my system I hardly visit here.
We're talking about a 35 year old being dismissed (and unemployable afterwards, poor bloke) and low 50's. Interestingly enough I spoke last week with someone whose relative attended a big optometrist's conference. There wasa presentation about a large rise in eye issues under 20 to 25 year olds and it was directly correlated to mobile phone use. Another study was showing eye issues of even younger people due to the brightness of small screens used in low light.... Our eyes are pretty sensitive.... I've found f.lux a life saver in the evening.
I finished a 0.53x dual Vifa. My first speaker project. Time passed quickly while cutting and gluing pieces, had to recut a few pieces due to being casual with my measurements.
The sound is certainly unique, rich, and very listenable. I will play around with the stuffing a bit, there's some boxiness in the midrange, evident sometimes on male vocals/piano/sax. I put polyfill inside the divider, and 0.5 inch patches of dampening around the chamber. I'm thinking about doubling those for 1 inch thickness and removing a bit of polyfill to loosen up the bass.
Will start building the 2nd in the next days, and now I want to try the 0.4x too, should be easy after 0.53x . This foamcore/hot glue combination is a revelation.
The sound is certainly unique, rich, and very listenable. I will play around with the stuffing a bit, there's some boxiness in the midrange, evident sometimes on male vocals/piano/sax. I put polyfill inside the divider, and 0.5 inch patches of dampening around the chamber. I'm thinking about doubling those for 1 inch thickness and removing a bit of polyfill to loosen up the bass.
Will start building the 2nd in the next days, and now I want to try the 0.4x too, should be easy after 0.53x . This foamcore/hot glue combination is a revelation.
I just ordered a TDA7297 for $3.02 w/free shipping. Ali has them as low as $2.26. It's unreal!
I hope I can do as well on a brick laptop supply.
I use 12v laptop smps on mine (actually a ps from an external hard drive). The 19v laptop supply will work and allow greater peak power but the amp really gets hot. Something like this works well, although costs more than the amp.
Amazon.com: 12V AC Adaptor Power Supply for Seagate 1TB External Hard Drive P/N 9SF2A4-500: Electronics
Amazon.com: 12V AC Adaptor Power Supply for Seagate 1TB External Hard Drive P/N 9SF2A4-500: Electronics
Cool. 😀
WRT the boxiness in the mids, nothing's free... You pay a bit for the extra gain in the midbass, kind of like with a horn. Still, you can get rid of most of it. It's more the front chamber than the rear chamber stuffing that affects this. Try sticking a bit of thin felt to the backs of the wings right in front of the driver. Something like felt furniture disks are good and easy. Those are the things used to keep the bottom of a vase from scratching grandma's furniture.
Thanks for the tip. I have a Maxtor HD that may be defunct or I found a similar switcher on Ali for $1.96.
Question; what's the input jack on the TDA7297, it's not listed on the specs?
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Jack is same as 12v hard drive smps - standard old school non proprietary power cord Jack (? 5.5mm or something like that?).
Sorry, my goof! I changed subjects mid stream and forgot to identify as audio jack on the TDA7297. Is it 3.5mm?
I meant jack on TDA7297 is the standard one that fits external HD power supplies. The audio is standard 3.5mm headphone stereo jack. You need a male to male or male to RCA to hook it up.
There is a thread on this combo in class D forum (although amp is technically class AB).
http://www.diyaudio.com/forums/class-d/253887-tda7297-karlsonator.html
There is a thread on this combo in class D forum (although amp is technically class AB).
http://www.diyaudio.com/forums/class-d/253887-tda7297-karlsonator.html
Much appreciated, the felt on the wings seems to have improved things quite a bit.
I have now finished the other side, and am very pleased with the results. I did not expect them to be this loud together. They are fun music-listening speakers that can rock or send you to sleep depending on the volume. I don't know yet where/how to place them in my room, but they seem to be fairly forgiving in that respect. I like how bass and mids are so lush. Just a good flowing sound all around. xrk971, thanks for being so encouraging in the foamcore threads, I wouldn't have tried this otherwise. I guess I won't be buying commercially made speakers anymore 😀
Some pics from the building, testing with tda7297 and finally with the dual tpa3116.
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Congratulations! So glad you like them - they are one of the best sounding speakers in DIY that is this low cost and easy to make too.
Another satisfied builder🙂
Latest design for Tang Band W5-2143
I had a request from JC Fardo in another thread to design a K'nator for the new Tang Band 5 incher. An impressive 91dB performance with f3 of 60Hz.
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-77.html#post4556005
0.60x scale in height and depth, 0.47x scale in width.
No BSC needed.
I had a request from JC Fardo in another thread to design a K'nator for the new Tang Band 5 incher. An impressive 91dB performance with f3 of 60Hz.
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-77.html#post4556005
0.60x scale in height and depth, 0.47x scale in width.
No BSC needed.
Has anyone tried 2 different drivers running parallel in the 0.53x? I thought it might be fun to try pairing the tc9 with a ps95-8 to get some extra top-end sparkle. The vifa are a bit too rounded-off for me at times. They are both 8ohm and have similar sensitivity.
Good idea. I think erik777 made a dual K'nator with 3FE25 on bottom and TC9FD on top. The PS95-8 with TC9 is a good combo. You want HF driver to be most exposed.
Pluvia 7 is good candidate.
http://www.diyaudio.com/forums/full-range/284525-new-mark-audio-pluvia-seven-3.html#post4575332
http://www.diyaudio.com/forums/full-range/284525-new-mark-audio-pluvia-seven-3.html#post4575332
excuse me xrk971 on post 1182 of the TABAQ thread you showed a plot of frequency response with relative harmonic distortion. I wonder if you have a similar plot for the 0.4mini karlsonator. Thank you for all your contribution
I must have posted this before but here it is again. This is with Faital Pro 3FE25. I don't have the data for TC9FD (lost).
Note that much of the HD below 400Hz is vibrations from the foam core K aperture - most notably the 200Hz peak. Make a double layer one and glue with latex caulking and it should take it down significantly. There is a mechanical buzz in the structure at several other frequencies that can be eliminated with fix to bracing.
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Thank you xrk971. It seems the TABAQ has lower and better controlled harmonic distortion. From simulation I expected the mini karlsonator to do better. Your charts show otherwise.
Thank you again and have a happy new year
Thank you again and have a happy new year
You mean this one with the curved wall TABAQ and the P830986 driver?
That certainly was a clean HD plot - the structure is a long tube with curved walls so inherently stiffer. If you made the 0.4x Knator with plywood it would have lower HD.
But the way the sound is disperesed, the K aperture makes it sound bigger and it doesn't require a BSC like the TABAQ which loses about 5dB sensitivity. That means the TABAQ is a 79dB speaker vs the 91dB 0.4 K'nator with the 3FE25.
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