This is all very interesting stuff chaps, some of which is a little beyond me right now. I realise my earlier subjective list of wants is more or less meaningless. What I can do is include my room dimensions, it's 15ft x 11ft x 9ft high, speakers have to fire down the length. It's a dedicated hifi room so my sofa is at the other end to the speakers and there's a big thick rug on the floor.
I think on balance the 168 drivers will be more than capable in my room and considering I'm happy with the Jimi Changs the safer bet is similarish version of what I already have, IE the Haruna..... I think.
Need to have a look at the cost of getting the wood professionally cut.
I think on balance the 168 drivers will be more than capable in my room and considering I'm happy with the Jimi Changs the safer bet is similarish version of what I already have, IE the Haruna..... I think.
Need to have a look at the cost of getting the wood professionally cut.
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X - To my knowledge, no one has shared sims/modeling of k-slot rearload horns. As with much of your recent work, you would seem to be paving the way for the bit of the web that I know about. Bill shared large quantities of measurements on the H.E. Asylum board (author: RCA-fan). Discussion of his k-slot horn (often called "K-horn" later) occurred on the forum ~2004-2008.
After a fair search there and in the Wayback Machine, the very sad status is that most of his images seem to be gone from AA and his newsletters escaped the Wayback. The posts remain, of course. The Wayback gallery of his website seems to be on a server that's down.
I will look to see what I have archived or on an old computer. For now, the only thing I have handy that hasn't already been posted here is this.
Attachments
There seems to be an version with what appear to be narrower channels
and version with more open channels.
These are quite significant differences, so I wonder which I should model?
Also, what is favored driver? The FE208E Sigma?
An externally hosted image should be here but it was not working when we last tested it.
and version with more open channels.
An externally hosted image should be here but it was not working when we last tested it.
These are quite significant differences, so I wonder which I should model?
Also, what is favored driver? The FE208E Sigma?
I don't know why the "ID Depth" is not simply shown with arrows as to what it represents on the picture. Everything else has arrows, this one is very ambiguous, I am guessing it is the distance from the bottom lip of the final divider to the front baffle?
Quite confusing. I was taking the 11.75 or 11.8 as the z axis (coming out of the image) in the first two images and in the image I posted, 11.75 as being the overall width including plywood thickness but that would make for ridiculously thin 1/4" thick plywood. I'll draw both these up in CAD tomorrow am and post more dimensions. Maybe only draw up one if one is considered obsolete by then.
Interesting how the horn mouth is depicted wildly different, nearly 4x bigger in one case (again no dimension directly shown).
Interesting how the horn mouth is depicted wildly different, nearly 4x bigger in one case (again no dimension directly shown).
TomLang,
I am pulling dims off of the drawing shown below using dial calipers (really the fastest way to get dimensions needed for modeling the geometry for Akabak). The mouth is probably an area of tweaking. For the first cut I will use the same Karlson function as for the K15 and see how that works. What is the internal width of the channels/cabinet? 11.75 inches?
I am pulling dims off of the drawing shown below using dial calipers (really the fastest way to get dimensions needed for modeling the geometry for Akabak). The mouth is probably an area of tweaking. For the first cut I will use the same Karlson function as for the K15 and see how that works. What is the internal width of the channels/cabinet? 11.75 inches?
An externally hosted image should be here but it was not working when we last tested it.
Which is the Jan 2013? I hope the red one because that is what I have already entered for the geometry and it was a pain. There are a lot of folds here.
The drawing you posted that has Jan 13 (new) horn written on it. I have no idea which one is correct or better. I will say this, the "red" one laid out perfectly in CAD. The other one has dimensional discrepancies...
Sim of RCAfan's K-slot BLH
Here is the simulation of the larger flow path design. Speaker is placed 4 ft away from a back wall, 2.83v input at 1 meter measured at centerline of driver position. This was a complicated speaker to model - one of the most complex to date that I have done. I have tried a bunch of drivers. Here are a few.
Here is the measurement (from Freddi's earlier post):
Fostex FE208 Sigma SPL vs Freq. I have a notch near 200 Hz and the low end of about 40 Hz is predicted. Also notches near 300 Hz, 450 Hz, and 700 Hz are also predicted.
Impedance
Cone Excursion (it is already hitting xmax at 1 watt input - not a recommended driver)
Let's try a Dayton PS220-8, SPL vs Freq
Impedance
Cone Excursion
And for grins lets put in an Eminence Beta 10CX coax
Personally, I think I like how the cheap Beta 10CX looks here - could be a lot of fun. No xmax issues either.
Here is the simulation of the larger flow path design. Speaker is placed 4 ft away from a back wall, 2.83v input at 1 meter measured at centerline of driver position. This was a complicated speaker to model - one of the most complex to date that I have done. I have tried a bunch of drivers. Here are a few.
Here is the measurement (from Freddi's earlier post):
An externally hosted image should be here but it was not working when we last tested it.
Fostex FE208 Sigma SPL vs Freq. I have a notch near 200 Hz and the low end of about 40 Hz is predicted. Also notches near 300 Hz, 450 Hz, and 700 Hz are also predicted.
Impedance
Cone Excursion (it is already hitting xmax at 1 watt input - not a recommended driver)
Let's try a Dayton PS220-8, SPL vs Freq
Impedance
Cone Excursion
And for grins lets put in an Eminence Beta 10CX coax
Personally, I think I like how the cheap Beta 10CX looks here - could be a lot of fun. No xmax issues either.
Attachments
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Broken record here, how about the Tannoy coax?
Tannoy 2046 8" Dual Concentric:
Znom: 8.000ohms
Revc: 4.400ohms
Sd: 196 cm^2
BL: 7.5253
Vas: 34.7
Cms: 635.4423 um/N
Mms: 23.2575g
Mmd: 21.6785g
Fi: 40.062Hz
Fo: 41.400Hz
Qms: 10.550
Qes: 0.470
Qts: 0.450
Pmax: 100W
Hvc: 10mm
Hag: 5mm
Xmax: 2.5mm
Cmx: 2.5mm
Cmo: 1mm
No: 0.51%
SPLo: 89.08dB
SPL 2.83V/m: 91.10
Tannoy 2046 8" Dual Concentric:
Znom: 8.000ohms
Revc: 4.400ohms
Sd: 196 cm^2
BL: 7.5253
Vas: 34.7
Cms: 635.4423 um/N
Mms: 23.2575g
Mmd: 21.6785g
Fi: 40.062Hz
Fo: 41.400Hz
Qms: 10.550
Qes: 0.470
Qts: 0.450
Pmax: 100W
Hvc: 10mm
Hag: 5mm
Xmax: 2.5mm
Cmx: 2.5mm
Cmo: 1mm
No: 0.51%
SPLo: 89.08dB
SPL 2.83V/m: 91.10
Firewood that sounds like a tomb.
I've heard it with 8" TB full range.
Would have to be 2004 version.
Change something drastic if you
got some ideas how to to fix it,
else don't waste your time...
I've heard it with 8" TB full range.
Would have to be 2004 version.
Change something drastic if you
got some ideas how to to fix it,
else don't waste your time...
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Kenpeter,
Saw your post in other thread. Zobsky did say you preferred the K12 better. When I looked at the impulse response of this speaker it has several very delayed echoes which is probably what you mean by it sounding like a tomb. The K15 or K12 on the other hand has a much tighter impulse response with less group delay.
Here is the impulse response for the W8-1772 in the K-slot BLH
Here is the impulse response of the W8-1772 in the K12
Here is the SPL vs Freq for the W8-1772 in a K12 (K15 scaled by 12/15)
Saw your post in other thread. Zobsky did say you preferred the K12 better. When I looked at the impulse response of this speaker it has several very delayed echoes which is probably what you mean by it sounding like a tomb. The K15 or K12 on the other hand has a much tighter impulse response with less group delay.
Here is the impulse response for the W8-1772 in the K-slot BLH
Here is the impulse response of the W8-1772 in the K12
Here is the SPL vs Freq for the W8-1772 in a K12 (K15 scaled by 12/15)
Attachments
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I'll be a bit kinder than kenpeter. I built both a kslot horn and a k12 . The kslot horn went lower but had 2 issues:
1. The bass was looser - the w8-1772 might not have had enough motor to driver the horn. Still, I love the driver.
2. The sound had a hollow ring to it -not sure why - might have been the final section resonating or the driver. Bass went down to the mid 40hz at least,perhaps lower
Re. A slit vent k12 I built and tried the same driver in, it sounded punchy down to 70 hz. Everything below that was missing.
On a side note, Doesn't anyone build anything anymore on these forums.. I see far too many threads consisting of pages and pages of armchair theorizing (nothing wring with that) but with no builds to speak of st the end. There is satisfaction in sawdust, even when the project fails.
1. The bass was looser - the w8-1772 might not have had enough motor to driver the horn. Still, I love the driver.
2. The sound had a hollow ring to it -not sure why - might have been the final section resonating or the driver. Bass went down to the mid 40hz at least,perhaps lower
Re. A slit vent k12 I built and tried the same driver in, it sounded punchy down to 70 hz. Everything below that was missing.
On a side note, Doesn't anyone build anything anymore on these forums.. I see far too many threads consisting of pages and pages of armchair theorizing (nothing wring with that) but with no builds to speak of st the end. There is satisfaction in sawdust, even when the project fails.
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