So are yoursNice speakers
At the moment, I am still listening and understanding the capabilities of my cardioid speaker. For now, I love them, and like them better than all other bookshelf type speakers I have heard so far
I think more experienced people here might be able to point out the utility of the cardioid concept in its intended placement scenarios in your case and compare with potential benefits disadvantages compared to the KEF blade type enclosure.
They look original, personal and well thought out/built. I'm soon going to hear the old Acoustic Research AR9 at friend's friend. Those should be the classics of classics, and father of well-designed speakers, a pride and joy that somehow seem to be slightly forgotten in most speakers produced since - which is why DIY is still fun - IMO.https://www.audioholics.com/editorials/acoustic-research-ar9
Always room for improvement and fun/play. But relax and enjoy your good work now
Alright, here is one secret as you probably discover it soon you could mount the woofer from the magnet. This would reduce resonances in the system, and likely simplify the construct/manufacturing, depending how complicated you want and need the magnet mount. If you want, you could leave the driver naked to simplify even further, or attach a rim/roundover to the driver rim, like you have now. The spokes on the "hole" to attach the rim to hte back "enclosure" are not needed anymore, except perhaps holding the damping material in place.
you could mount the woofer from the magnet. This would reduce resonances in the system, and likely simplify the construct/manufacturing, depending how complicated you want and need the magnet mount. If you want, you could leave the driver naked to simplify even further, or attach a rim/roundover to the driver rim, like you have now. The spokes on the "hole" to attach the rim to hte back "enclosure" are not needed anymore, except perhaps holding the damping material in place.
Before doing so check for basket resonances, just hold the driver magnet and knock the basket. Some drivers sound like bells!
Nice article about passive cardioid here
https://audioxpress.com/article/patent-review-passive-cardioid-speaker
https://audioxpress.com/article/patent-review-passive-cardioid-speaker
I wonder if this technique can be used to suppliment the traditional nearfield measurement and whether it will be of any benefit (like identifying potential resonances etc) in the upto 1000Hz frequency range
https://audioxpress.com/article/mea...Q-CCfDDd2z32ywqsql-H4eOoqwJMOn0uWidQjhi5R1xWY
The signal processing descibed seems to be easily implementable with REW and VituixCAD. Only additional requirement seems to be an additional mic
Andrew Jones over at another forum says the following:
"I've used this basic technique for years.
You don't need hardware to implement it or even two mics. If you lock your reference timing when you make a measurement you can do it by moving a single mike and make two sequential measurements that you subtract and process. You do however compromise low frequency S/N ratio"
https://audioxpress.com/article/mea...Q-CCfDDd2z32ywqsql-H4eOoqwJMOn0uWidQjhi5R1xWY
The signal processing descibed seems to be easily implementable with REW and VituixCAD. Only additional requirement seems to be an additional mic
Andrew Jones over at another forum says the following:
"I've used this basic technique for years.
You don't need hardware to implement it or even two mics. If you lock your reference timing when you make a measurement you can do it by moving a single mike and make two sequential measurements that you subtract and process. You do however compromise low frequency S/N ratio"
nice! Here is another over-my-head way to measure and process
https://www.diyaudio.com/community/...ons-measurement-in-matlab.388032/post-7168757
https://www.diyaudio.com/community/...ons-measurement-in-matlab.388032/post-7168757
This post has nothing to do with my speaker build(s).
But I am posting the details from one of Kimmosto's designs (that I got from the internet) for reference, learning purposes and discussion.
The Speaker
and the curves
and Kimmosto's response to someone who commented that the directivity can be improved:
"Of course, but fortunately it's just indirect result of calculation, and significance is low compared to "direct" magnitude responses, different power averages, whole concept including level of directivity, quality of components, timing etc. Designer and many listeners happens to prefer conventional tweeters so visually perfectly linear DI response is not primary target with 6.5" mid-woofer."
But I am posting the details from one of Kimmosto's designs (that I got from the internet) for reference, learning purposes and discussion.
The Speaker
and the curves
and Kimmosto's response to someone who commented that the directivity can be improved:
"Of course, but fortunately it's just indirect result of calculation, and significance is low compared to "direct" magnitude responses, different power averages, whole concept including level of directivity, quality of components, timing etc. Designer and many listeners happens to prefer conventional tweeters so visually perfectly linear DI response is not primary target with 6.5" mid-woofer."
This feature is interesting to me, and it is something I have incorporated into some of my designs.
There is an on-axis dip of about -2 dB from 3k to 6k. This dip allows the power response to have a smoothly decreasing slope over the whole range. If the on-axis was flat, the power response would have a + 2 dB peak from 3k to 6k.
I have found that a rising power response in the region from 1k - 8k can make a speaker harder to place in a room... It becomes more finicky about placement.
I agree with his comment on directivity index. I have concluded that a smooth DI is important up to a point. Wild swings in the DI curve (5 dB or more) will usually have a negative impact on the sound quality. But small +/- 2 dB variations in the DI curve don't seem to matter very much compared to one which has been optimized to be very flat.
Very interesting speaker. He is able to maintain excess group delay to less than 0.5ms all the way down to 50 Hz, which is very impressive... not sure how he does that. But that is why he is Kimmosto, and I am merely me...
There is an on-axis dip of about -2 dB from 3k to 6k. This dip allows the power response to have a smoothly decreasing slope over the whole range. If the on-axis was flat, the power response would have a + 2 dB peak from 3k to 6k.
I have found that a rising power response in the region from 1k - 8k can make a speaker harder to place in a room... It becomes more finicky about placement.
I agree with his comment on directivity index. I have concluded that a smooth DI is important up to a point. Wild swings in the DI curve (5 dB or more) will usually have a negative impact on the sound quality. But small +/- 2 dB variations in the DI curve don't seem to matter very much compared to one which has been optimized to be very flat.
Very interesting speaker. He is able to maintain excess group delay to less than 0.5ms all the way down to 50 Hz, which is very impressive... not sure how he does that. But that is why he is Kimmosto, and I am merely me...
Step response and excess group delay look like there is linear phase filters, so you can do it as well with processor that has FIR filter capability!
