I own a pair of these drivers and was thinking of front-horn (conical) loading them between approx. 300 - 3000 KHz. Does anyone have any opinions on this idea?
Judging by some crude cardboard experiments I tried (crude is a understatement), it was the most natural of the drivers I tried (PR 17OMO, Tangband W8-1772, Fostex FE-166E), though obviously limited in top end extension.
https://www.madisound.com/store/product_info.php?products_id=90
Judging by some crude cardboard experiments I tried (crude is a understatement), it was the most natural of the drivers I tried (PR 17OMO, Tangband W8-1772, Fostex FE-166E), though obviously limited in top end extension.
https://www.madisound.com/store/product_info.php?products_id=90
It could work OK. Adrian Mack did a conical based around the Eminence A6 some years ago but the Geocities page is long gone. It did 300-2k.
Some discussion about similar stuff in this old thread, which also has a link to Adrian's page - maybe you can find it in the wayback machine.
You could also do an OS without a lot if extra effort and round would be possible using a laminate of sheets, cut with a router and a 45* bit.
Some discussion about similar stuff in this old thread, which also has a link to Adrian's page - maybe you can find it in the wayback machine.
You could also do an OS without a lot if extra effort and round would be possible using a laminate of sheets, cut with a router and a 45* bit.
What's wrong with my sim?
From first principles:
Let's assume a Fc = 250 Hz conical
for 4 pi loading, (free space),
speed of sound = 340 m/s
wavelength at cutoff , w = c / Fc = 1.36 m = perimeter of horn mouth
Radius of mouth rm= w / (2 * pi ) = 0.21 m
Therefore, mouth area Am = pi * rm^2 = 0.1386 m2
Assuming Horn length Hl= w/2, Hl = 0.68 m
Substituting these into horn resp, and using a throat aread = Sd, I get awful results, even after tweaking things around. The sim shown has a throat chamber, but there's little difference with / without it.
What gives ?
Driver specs:
Impedance 8 ohm
Resonance 117Hz
Power 100W
Sensitivity 100dB
Re 6.2 ohm
Le 0.73mH
BL 8.24
X-max 0.5mm
Cms 0.2 mm/N
Qms 3.16
Qes 0.61
Qts 0.51
Mms 9.17g
Sd 139 cm2
Vas 5.52 liters
Magnet weight 31 oz
Speaker weight 5.5 lbs
From first principles:
Let's assume a Fc = 250 Hz conical
for 4 pi loading, (free space),
speed of sound = 340 m/s
wavelength at cutoff , w = c / Fc = 1.36 m = perimeter of horn mouth
Radius of mouth rm= w / (2 * pi ) = 0.21 m
Therefore, mouth area Am = pi * rm^2 = 0.1386 m2
Assuming Horn length Hl= w/2, Hl = 0.68 m
Substituting these into horn resp, and using a throat aread = Sd, I get awful results, even after tweaking things around. The sim shown has a throat chamber, but there's little difference with / without it.
What gives ?
Driver specs:
Impedance 8 ohm
Resonance 117Hz
Power 100W
Sensitivity 100dB
Re 6.2 ohm
Le 0.73mH
BL 8.24
X-max 0.5mm
Cms 0.2 mm/N
Qms 3.16
Qes 0.61
Qts 0.51
Mms 9.17g
Sd 139 cm2
Vas 5.52 liters
Magnet weight 31 oz
Speaker weight 5.5 lbs
Attachments
0.5mm xmax isnt much at 200hz, considering its only a 6"
well, maybe ok at normal SPL
might work better with 500hz xo
well, maybe ok at normal SPL
might work better with 500hz xo
Yes, .but in reality, .. you achieved that mainly by whittling down the cone mass to nothing. Not practical 🙂
For what it's worth, one of the reasons I was interested in trying out a conical horn is that the below mentioned router bits should make construction much easier. I picked up some clones of the following bits off ebay last week.
Multi Sided Glue Joint Router Bits
The technique can be applied to tapered boxes ie. conical horns too, as described in
http://mlcswoodworking.com/orderstatus/html/smarthtml/graphics2/plans-8-sided-planter.pdf
Multi Sided Glue Joint Router Bits
The technique can be applied to tapered boxes ie. conical horns too, as described in
http://mlcswoodworking.com/orderstatus/html/smarthtml/graphics2/plans-8-sided-planter.pdf
No free lunch anyway.
In reality, such big throat horn with a cone driver would deliver more higher end of frequency range than the sim we're playing here. Drivers with rising FR help a lot.
In reality, such big throat horn with a cone driver would deliver more higher end of frequency range than the sim we're playing here. Drivers with rising FR help a lot.
Otherwise , a folded front horn ! I own two of these little beasts and I was doing the usual run in . Since they play loud , I covered with some sheets of wood the front emission ,partially making a multi-diffractional surface . The 17 PR Mo were in their 2 liter boxes ,as I intend to have them mounted flat on a baffle for a 3 way. But the sound ,horribly harsh for a whole afternoon ,became sweet in the evening . And they kept playing with cushions and tables around for a day . And the sound being very 'midrangy' and warm , making the bass notes 'predictable' being crossed at about 500 Hz .
An atypical cabinet ,where you see the back of the driver ,could be done and the folded horn with about 50 cm length brings his emission to the front with a mouth of about 30 cm2 . Geometry and design needs to be a bit lesser rough than for bass .
I plan to have them flush mount 😛
An atypical cabinet ,where you see the back of the driver ,could be done and the folded horn with about 50 cm length brings his emission to the front with a mouth of about 30 cm2 . Geometry and design needs to be a bit lesser rough than for bass .
I plan to have them flush mount 😛
Last edited:
Aargh !! Are you talking about Diffraction Slot enclosures,.. a-la Karlson or RJ ?
RJ compared to Karlsons and Elliptoflex, and even BBC slots?
Or this: ... Horn-Sat . If this is what you're referring to, I don't see the point of a reentrant horn, apart from slightly loading the mid-bass
re: Alpha 6 on Mack's conical, here's what I measured vs an alnico LE5 on Edgar's 250hz tractrix - -have you tried 166 in a K-coupler?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
]
Wow! that tractrix looks pretty "CD" to me !
And that conical perform better off axis to my eyes.
Such results are totally beyond my expectation.
And that conical perform better off axis to my eyes.
Such results are totally beyond my expectation.
ok folks, we can debate this till kingdom come or I can build a prototype. I vote the latter since I have a few 6.5 / 8" drivers in my posession
Freddy, any idea what the dimensions were for that conical?
I did try fe 166 in my k12 and they did fairly well, though in the end that project didn't
make it past prototype stage
Freddy, any idea what the dimensions were for that conical?
I did try fe 166 in my k12 and they did fairly well, though in the end that project didn't
make it past prototype stage
picowallspeaker said:
If a driver sounds 'midrangy' and warm, I guess it will be overly warm by an "ordinary" front horn, because the horn would enhance the lower portion of the working band.
So it seems, this driver inevitably needs a shallow/large mouth WG type of thing, if you insist building a horn around it and/or without severe EQ afterwards.
I remember I've read several times that people had tried it with horns with negative results, instead, many people like it very much in just plain sealed box.
Good luck.
- Status
- Not open for further replies.