hi SredniVashtar - - how's your aperture tests coming along? - your double PA130 XKi sim is very potent and cost effective for drivers😀 - two PA130 are just the cost of a cheap compression driver, or a couple of inductors and cheap caps
Srednivashtar,
If you have a measurement mic please take some measurements at 0.5m and share. I would love to see what SPL sensitivity you achieve.
If you have a measurement mic please take some measurements at 0.5m and share. I would love to see what SPL sensitivity you achieve.
I don't have such a mic but I ought to get one. I saw a very cheap one on Amazon that supposedly comes with a calibration chart.
Dayton Audio iMM-6 Calibrated Measurement Microphone for iPhone iPad Tablet and Android: Amazon.co.uk: Musical Instruments
The AudioTool app for android supposely supports this.
Dayton Audio iMM-6 Calibrated Measurement Microphone for iPhone iPad Tablet and Android: Amazon.co.uk: Musical Instruments
The AudioTool app for android supposely supports this.
That can work by wont allow you to use with software like REW. Dayton UMM-6 costs more but can work well. Dayton EMM-6 is good too but needs mic preamp with phantom 50v. UMIK-1 from miniDSP is what I currently use.
Still, I have one of those and it does work with my iphone / ipad / audiotools . IIRC, audiotools isn't free so factor that into your cost calculations. Not as convenient as full blown REW but significantly cheaper.
Useful piece of gear though.
Does Dayton provide any included app for iPhone or Android with their little mic? I agree at that price it's handy to have. Like a cheap SPL meter or similar.
hi xrk971 - - regarding your 60 liter XKi cabinet for w8-1772 and Beta10cx, will my P-Audio SN10 (or Delta 10A) also work acceptably ? I think SN10C's real qts is lower than their spec but lost all drivers for WT3 and TrueRTA when my pc died a few weeks ago
SN10C
fs 67.3, Re 5.4, Le 0.30mH, Qms 4.735, Qes 0.503, Qts 0.455 Vas 27.18, BL 12.6, MMs 35.01g Sd 340, Xmax 2.8mm, half space Eff = 1.59%, Airgap height 9.5mm, Voice coil height 15mm
60 liter XKi plan and 1772 sim:
http://www.diyaudio.com/forums/full...o-karlson-6th-order-bandpass.html#post4198019
SN10C
fs 67.3, Re 5.4, Le 0.30mH, Qms 4.735, Qes 0.503, Qts 0.455 Vas 27.18, BL 12.6, MMs 35.01g Sd 340, Xmax 2.8mm, half space Eff = 1.59%, Airgap height 9.5mm, Voice coil height 15mm
60 liter XKi plan and 1772 sim:
http://www.diyaudio.com/forums/full...o-karlson-6th-order-bandpass.html#post4198019
Thanks for the suggestions. I suppose even if I connect iMM-6 to my laptop, I still need to calibrate for the ADC and gain in the soundcard. Having a USB version already has that taken care of.
I managed to cut the Karlson appertures based upon your equation I found in a thread somewhere. Widened it to 8mm at the top as that was the smallest sharp router cutter I had to hand. Taped on and quick test as I have to go out this evening. Just listened to The Planets, Neptune, and they sound good. Powerful bass. Slightly boxy on some violin notes, but I haven't added any felt to the front chamber or stuffing to the rear. So far, so good.
An externally hosted image should be here but it was not working when we last tested it.
is that aperture formed from a particular radial arc swing? - it'll be interesting to hear your report of how it does with various instruments and vocal ranges - - btw, I think your build is at the top of the list for aesthetics and proportion
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Srednivashtar,
I am with Freddi on this one - beautiful lines! I want one now😀
I find that even with one PA130-8, the bass was pretty nice. Can't imagine what two would be like.
Great job.
I am with Freddi on this one - beautiful lines! I want one now😀
I find that even with one PA130-8, the bass was pretty nice. Can't imagine what two would be like.
Great job.
SredniVashtar,
Agree freddi and xrk971 a beautiful clean build.
Have best evening but must say personal would have a hard time leaving build progress, thanks sharing.
Agree freddi and xrk971 a beautiful clean build.
Have best evening but must say personal would have a hard time leaving build progress, thanks sharing.
hey xrk971 - what's the general differences you've heard in a single vs double driver mini-Karlsonator ?
Freddi,
Doubling a driver means a bigger box so lower bass tuning plus increased sensitivity by 6dB so a huge jump in sound volume sensitivity. It's night and day and better all around.
Doubling a driver means a bigger box so lower bass tuning plus increased sensitivity by 6dB so a huge jump in sound volume sensitivity. It's night and day and better all around.
Srednivashtar,
You have been working on this quite dilligently starting with a foam core prototype. Did your wood version end up with the same dimensions? If you can please provide a sketch or drawing of your box design that would be great. Or maybe you did but I missed it?
http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-42.html#post4590425
You have been working on this quite dilligently starting with a foam core prototype. Did your wood version end up with the same dimensions? If you can please provide a sketch or drawing of your box design that would be great. Or maybe you did but I missed it?
http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-42.html#post4590425
Thanks for the kind words. I am very pleased with the speakers, although there is still some tweaking and finishing to do.
freddi, I based the aperture curve on a quadratic that xrk971 posted in another thread. I altered the coefficients slightly to allow for a wider 8mm slot at the top.
y = (0.991x^2 + 0.009x) * 11.25 + 0.4 cm
where x runs from 0 to 1 along the length of the aperture.
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-15.html#post3721633
I have attached my calculations that I used to cut the stencil.
Cutting the aperture was easier than I expected. I marked out on a scrap piece of plywood every cm, and drew a fairly smooth pencil line. Cut it first with a jigsaw, then got it fairly close freehand with a router and finally used an electric sander to obtain a smooth curve. I clamped the stencil on to the plywood (allowing for the guide bushing), cut one side, flipped it over and cut the other.
xrk971, these are slightly larger in depth than the foamcore protypes but same internal width and height. The duct is shorter and higher compared to the foamboard prototype: from 26 cm x 2.8cm to 23.4 cm x 3.0cm. I also mounted the drivers closer together. New dimensions are in post below:
http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-48.html#post4654093
freddi, I based the aperture curve on a quadratic that xrk971 posted in another thread. I altered the coefficients slightly to allow for a wider 8mm slot at the top.
y = (0.991x^2 + 0.009x) * 11.25 + 0.4 cm
where x runs from 0 to 1 along the length of the aperture.
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-15.html#post3721633
I have attached my calculations that I used to cut the stencil.
Cutting the aperture was easier than I expected. I marked out on a scrap piece of plywood every cm, and drew a fairly smooth pencil line. Cut it first with a jigsaw, then got it fairly close freehand with a router and finally used an electric sander to obtain a smooth curve. I clamped the stencil on to the plywood (allowing for the guide bushing), cut one side, flipped it over and cut the other.
xrk971, these are slightly larger in depth than the foamcore protypes but same internal width and height. The duct is shorter and higher compared to the foamboard prototype: from 26 cm x 2.8cm to 23.4 cm x 3.0cm. I also mounted the drivers closer together. New dimensions are in post below:
http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-48.html#post4654093
I had a go at modelling these in Akabak this morning. Bear in mind that I am a novice at this, and I may be wrong. If you are using xrk971's plans for the RS100P-4 - the 5" x 9" x 7.5" box, I think the duct is too long for the 4fe35 driver causing it to tune too low. In the SPL plots below, you can see the effect of removing the rear 2.5" section of duct.
Original Duct
An externally hosted image should be here but it was not working when we last tested it.
Shortened Duct
An externally hosted image should be here but it was not working when we last tested it.
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hi SredniVashtar - - thank you very much for the details - am torn between your design and a 2.8 cubic foot bulk XKi for W8-1772 and alternately, Beta10cx. Your double PA130 K may sound better and certanly more coherent overall than the coax and perhaps better than the expensive TangBand driver. (Two PA130 have the same area as one Alpair 12P)
I wonder if a double driver XKi can be made to advantage with 8-12" drivers - ?
I wonder if a double driver XKi can be made to advantage with 8-12" drivers - ?
Double 8-12" drivers - now that would be a monster!
The Karlson aperture really helps with diffraction effects. Before I put it on, the comb effect was quite pronounced in the vertical plane, but this disappeared. Same with directionality in the horizontal plane. The speakers go lower with the aperture mounted - dropping off below 39 Hz!
The Karlson aperture really helps with diffraction effects. Before I put it on, the comb effect was quite pronounced in the vertical plane, but this disappeared. Same with directionality in the horizontal plane. The speakers go lower with the aperture mounted - dropping off below 39 Hz!