Wow, that was a long time ago and I had forgotten all about it. If I recall, the tuning was lower than modelled and I would make the upper coupling port a little shorter if I built them again. I got akabak to run under wine on Linux. Had a quick look and couldn't find any of my old akabak models.
Cool to see you again ! - another thing to consider in these top vent K type would be to try NEXO's K-slotted vent approach and see how that affects response in the midrange. That might help reduce some dip depth.
https://patentimages.storage.googleapis.com/pdfs/4bc54951ae7cf8988ea3/US20150222984A1.pdf
https://patentimages.storage.googleapis.com/pdfs/4bc54951ae7cf8988ea3/US20150222984A1.pdf
Thanks. I sold my house 2 years ago and only kept what I could fit in a rucksack, so got rid of all my audio stuff. Made the mistake of moving to Sweden to escape from Brexit. Waited a year for my residency application to be processed, which was refused so moved back to the UK and bought an old cottage in the north Pennines. Once I get some heating, going to work on speakers. Quite interested in the 10F/8424 & RS225-8 FAST / WAW Ref Monitor.
Sorry about attempted move to Sweden. Sweden is a nice place to live I hear - but I guess not so easy to become a resident alien. That’s too bad you don’t have all your audio stuff anymore.
But it’s liberating to start tabula rasa.
Check out the XSD speaker.
But it’s liberating to start tabula rasa.
Check out the XSD speaker.
Perhaps it is better that I don't discuss Scandinavia beyond saying that it is not the nirvana portrayed in some quarters, Compared with the UK, it is very backward: racist, sexist and homophobic.
I saw the XSD. It looks like a challenging build. Maybe...
I saw the XSD. It looks like a challenging build. Maybe...
with horrible inlfation - many speakers just don't look their current price, including many Eminence. Madisound has Beta 8A relatively cheap - I wonder how a dual Beta 8A XKi with k-tube on top would fare.
So I built the PA130 XKI years ago, and was very impressed with the performance. However, over time I began to notice that it seems to have a somewhat objectionable midrange that only shows up on certain songs, probably ones that emphasize a certain frequency range.
Tonight I was comparing them side by side with my even older Sachiko with FE206 drivers and I was struck by how much you get out of the small XKIs. They actually sounded better at lower volumes. I guess that there is a certain spl to make the Sachiko's do their thing. Of course, the Fostex drivers are way more HD than the PA130s.
Anyway, I was thinking about replacing 1 driver in each box to try to blend the frequency response. Maybe a terrible idea, but I wouldn't mind spending a little to test. Something like a Visaton BG13P ?
Or would the MA CHP-90 work as a drop in replacement if I replace all 4? Are there other drivers that might fit that I should consider?
Thanks for any suggestions!
Tonight I was comparing them side by side with my even older Sachiko with FE206 drivers and I was struck by how much you get out of the small XKIs. They actually sounded better at lower volumes. I guess that there is a certain spl to make the Sachiko's do their thing. Of course, the Fostex drivers are way more HD than the PA130s.
Anyway, I was thinking about replacing 1 driver in each box to try to blend the frequency response. Maybe a terrible idea, but I wouldn't mind spending a little to test. Something like a Visaton BG13P ?
Or would the MA CHP-90 work as a drop in replacement if I replace all 4? Are there other drivers that might fit that I should consider?
Thanks for any suggestions!
ajh, was this a double PA130? I think it would be possible to play around with the tuning to deal with the midrange, or incorporate a stuffed pipe to damp down a peak. I built a pair of doubles several years back and they had great bass - the timpani in this recording sounded amazing.
I think the PA130’s have a great midrange, natively. It might be that the XKI aperture is enhancing or subtracting something unpleasant or you might need more damping pads on the front chamber. Add more stuffing inside.
The BG13P is really a midrange and tweeter and does not have much below 300Hz. You might miss out on the nice bass you have.
Try running it without the front aperture and see if that resonance effect goes away. That will tell you it needs more damping pads on front.
If you have a CHP-90 ready to try and it is drop in - go for it. But I wouldn’t go and get it for this experiment. Risky.
What you may be lacking is some “air” - try a super tweeter like a small compact dome tweeter with a 1uF cap.
Like this one - cut a small hole above the aperture apex and install like a cyclops eye.
Good luck!
Yeah, it is a double PA130. I agree about the bass. Compares favorably to much larger speakers - which is why I want to optimize them.
I have had the aperture off for quite some time as I didn't like the first one - mainly due to my wood working skills. I was experimenting with stuffing the slot (hehehe) last night but it might take some time to sort it out b/c it seems elusive. I will likely have to identify a specific section of a specific track to test with over and over. However, I doubt my ear is good enough to associate what I hear with specific frequency response well enough.
Perhaps I should remake the front baffle before doing too much.
I have had the aperture off for quite some time as I didn't like the first one - mainly due to my wood working skills. I was experimenting with stuffing the slot (hehehe) last night but it might take some time to sort it out b/c it seems elusive. I will likely have to identify a specific section of a specific track to test with over and over. However, I doubt my ear is good enough to associate what I hear with specific frequency response well enough.
Perhaps I should remake the front baffle before doing too much.
That is a Sachiko with a Fostex Fe206E. Sachiko Plan available here...
The ones on this page are similar designs for various drivers: Spawn Family
The ones on this page are similar designs for various drivers: Spawn Family