Its self adhesive rubbery window seal stuff that I have had on the driver to seal it into my backhorns.
Yes it is, although i suspect its not a particularly worthwhile effort (its just felt), something heavier would probably be better.
Umm well i was thinking of offering copies at a price.... probably around 90GBP per horn to cover materials and my time, but I wont be able to do any till august or so as I'm up to my eyeballs with work for my degree at the moment. I'll finalise the price then and will be able to include plans for mounting rings and places to get the backchamber bits and pieces (i.e. what you'll need to finish it off)
Do you think this is a worthwhile mod? If so where do I buy it, I've done about everything else to these drivers already so am willing to give it a whirl.
Well perminent untill I get my hands on something better. Its only held on with double sided tape so easily removed - offered marginal improvements in my backhorn.
Greets!
I can't tell in the pic if you did the $0.98 tweak: http://web.archive.org/web/20020628234451/http://www.mindspring.com/~darmah/lowther/mods.htm
Mass loading the driver is a good plan also: http://web.archive.org/web/20020620215724/http://melhuish.org/audio/images/press-screw.gif
GM
I can't tell in the pic if you did the $0.98 tweak: http://web.archive.org/web/20020628234451/http://www.mindspring.com/~darmah/lowther/mods.htm
Mass loading the driver is a good plan also: http://web.archive.org/web/20020620215724/http://melhuish.org/audio/images/press-screw.gif
GM
wow ive been listening to the horns rich has made and they are amazing- ive heard a lot of very expensive systems and these are up there with the very best- and thats with MP3's from laptop soundcard being played through a 25 year old marantz amp!
the soundstage is huge and the midrange sounds so effortless and smooth.
if youve never heard front horns go listen to some theyre great
pic here:http://www-student.lboro.ac.uk/~cdrabw/12.jpg
note my scanspeak 8555 in a crappy mdf box being used for bass duties hehe
ps whats also funny is the retro power meters on the front of the amp barely nudging 0.1 watts at ear-breaking volume levels
the soundstage is huge and the midrange sounds so effortless and smooth.
if youve never heard front horns go listen to some theyre great
pic here:http://www-student.lboro.ac.uk/~cdrabw/12.jpg
note my scanspeak 8555 in a crappy mdf box being used for bass duties hehe
ps whats also funny is the retro power meters on the front of the amp barely nudging 0.1 watts at ear-breaking volume levels
lufbramatt ,
now you need a "small" cornerhorn,
take a view:
http://www.hm-moreart.de/99.htm
pics, measurements, free download
now you need a "small" cornerhorn,
take a view:
http://www.hm-moreart.de/99.htm
pics, measurements, free download
Hi Richard,
I'm crazy about what I saw and have to build a pair myself.
Could you please post all the drawings of your project (horn, bass cabinet) with every detail so as a non-technical person as I am can do it?
You could also e-mail the detailed design to me: tta@fpt.vn
God bless you!
TTA
I'm crazy about what I saw and have to build a pair myself.
Could you please post all the drawings of your project (horn, bass cabinet) with every detail so as a non-technical person as I am can do it?
You could also e-mail the detailed design to me: tta@fpt.vn
God bless you!
TTA
Round Tractrix Bell how to?
Does any one no how to calculate the curve of the bell after the Tractrix is calculated?
The tractrix programs I have calculate the curve up to the 90 degree point, but do not add this nice round curve bell?
Could I get a copy of the curve for CAD program? Thanks, Bill
Does any one no how to calculate the curve of the bell after the Tractrix is calculated?
The tractrix programs I have calculate the curve up to the 90 degree point, but do not add this nice round curve bell?
Could I get a copy of the curve for CAD program? Thanks, Bill
Hi Bill,
I just made the curve up to look about 'right'. I may be wrong but different Oris 200s appear to have different radius curves at the end - different revisions? I just continued with a curve that fit in with the end of the tractrix curve in CAD.
I've attached a PDF with a 1:1 scale drawing of the curve I used, the end curve doesnt look as smooth now as I remember it, but that is what I used to cut the scraper to for the plaster mould.
Thanks for your comments qi, there are going to be a few miner alterations from the most recent rendering I've put up, but they are as I say only minor.
The software I (and my friend lufbramatt here at loughborough) use is PTC pro/ENGINEER Wildfire 2.0 with a Lightwave plugin for rendering - Steep learning curve but probably the most powerful CAD software that I know of, certainly more than Solidworks for example, and having the Lightwave plugin makes life easier than having to export/import things into 3D MAX or whatever.
Incase anyone here in the UK near Loughborough is interested, in June you can come along to mine and matts degree show and take a look (and hopefully a listen) to what we've done. You'll also be able to have a look at the various wonders our other industrial design collegues have come up with aswell! - I'm pretty certain entry is free and its open all weekend.
For more information click here and here.
Richard.
I just made the curve up to look about 'right'. I may be wrong but different Oris 200s appear to have different radius curves at the end - different revisions? I just continued with a curve that fit in with the end of the tractrix curve in CAD.
I've attached a PDF with a 1:1 scale drawing of the curve I used, the end curve doesnt look as smooth now as I remember it, but that is what I used to cut the scraper to for the plaster mould.
Thanks for your comments qi, there are going to be a few miner alterations from the most recent rendering I've put up, but they are as I say only minor.
The software I (and my friend lufbramatt here at loughborough) use is PTC pro/ENGINEER Wildfire 2.0 with a Lightwave plugin for rendering - Steep learning curve but probably the most powerful CAD software that I know of, certainly more than Solidworks for example, and having the Lightwave plugin makes life easier than having to export/import things into 3D MAX or whatever.
Incase anyone here in the UK near Loughborough is interested, in June you can come along to mine and matts degree show and take a look (and hopefully a listen) to what we've done. You'll also be able to have a look at the various wonders our other industrial design collegues have come up with aswell! - I'm pretty certain entry is free and its open all weekend.
For more information click here and here.
Richard.
rabw,
Could you give a more descriptive tips on building using fiberglass. I have never done this, so would be interested in a detailed procedure on how to do this. How thick does the horn walls need to be?
I am sure you would have a lot of great tips now that you have completed a pair.
Thanks in advance,
Bill
Could you give a more descriptive tips on building using fiberglass. I have never done this, so would be interested in a detailed procedure on how to do this. How thick does the horn walls need to be?
I am sure you would have a lot of great tips now that you have completed a pair.
Thanks in advance,
Bill
Hi tade,
Because there is obviously no flex in the plaster mould I dont think you'll very easily remove the moulding from it. We wrestled for over an hour and gave up, resorting to destroying the plug. The plaster mould was coated in upol reface to get a smooth shiny finish, and this peeled off the GRP fairly easily. After it was removed a new mould was made off the 1st moulding. Since then I've taken the 2 dark grey horns off that which I will use - new mould should be good for many more horns.
Bill, I'd never gone anywhere near fibreglass either, but its not too bad. I used 450GSM chop strand (I think) with 2 layers over the whole horn, a 3rd layer blending in around the rim/mouth end to about halfway down the flare. Obviously first gel coat is applied and left to dry then you layup onto that. Main thing with chop strand is to use a straight edge such as a bit of board and to tear along it, if you cut with scissors you'll be left with a hard edge that'll be difficult to blend in. On my horns you cannot see any intersection between segments, its all uniform and even. Also for laying up I really advise you get hold of a wire wound roller, this is used once the chop strand is all covered in resin to get all the bubbles out, and it really works well. The laying up each time took me around 2-2.5 hours. I put 1.5% catalyst in instead of the typical 2% to give me a bit longer to faff around and get it perfect. The wall thickness of my horns is around 3-4mm thick, I used alot of gel coat (so I can rub back into it) and quite alot of resin aswell - apparently this makes the moulding more brittle, but i havent had any problems and they're very very stiff.
Cortez, yes I have throught about that idea since getting a long way into the project. It is a nice idea and perhaps something I can do in the future. Whether it will be any better than the simple bass solution I have planned is debatable. My FE206e's in the reccomended backhorns have always been a bit bass shy, but not too bad in the right room. I find it makes a large difference what material you play - because of the uneven low end of the backhorns the bass in music can be good or bad depending on how lucky you are that its at the right frequency for the speaker!
Richard.
Because there is obviously no flex in the plaster mould I dont think you'll very easily remove the moulding from it. We wrestled for over an hour and gave up, resorting to destroying the plug. The plaster mould was coated in upol reface to get a smooth shiny finish, and this peeled off the GRP fairly easily. After it was removed a new mould was made off the 1st moulding. Since then I've taken the 2 dark grey horns off that which I will use - new mould should be good for many more horns.
Bill, I'd never gone anywhere near fibreglass either, but its not too bad. I used 450GSM chop strand (I think) with 2 layers over the whole horn, a 3rd layer blending in around the rim/mouth end to about halfway down the flare. Obviously first gel coat is applied and left to dry then you layup onto that. Main thing with chop strand is to use a straight edge such as a bit of board and to tear along it, if you cut with scissors you'll be left with a hard edge that'll be difficult to blend in. On my horns you cannot see any intersection between segments, its all uniform and even. Also for laying up I really advise you get hold of a wire wound roller, this is used once the chop strand is all covered in resin to get all the bubbles out, and it really works well. The laying up each time took me around 2-2.5 hours. I put 1.5% catalyst in instead of the typical 2% to give me a bit longer to faff around and get it perfect. The wall thickness of my horns is around 3-4mm thick, I used alot of gel coat (so I can rub back into it) and quite alot of resin aswell - apparently this makes the moulding more brittle, but i havent had any problems and they're very very stiff.
Cortez, yes I have throught about that idea since getting a long way into the project. It is a nice idea and perhaps something I can do in the future. Whether it will be any better than the simple bass solution I have planned is debatable. My FE206e's in the reccomended backhorns have always been a bit bass shy, but not too bad in the right room. I find it makes a large difference what material you play - because of the uneven low end of the backhorns the bass in music can be good or bad depending on how lucky you are that its at the right frequency for the speaker!
Richard.
Despite non-sense audiophile market trends, a custom-made active crossover is a must for such a system, because the signal going to the bass driver must be delayed and phase shifted to match the transfer characteristics of the horn, and the required low-pass and high-pass filter curves in order to get perfect on axis summing are usually quite far from "complimentary".
I only enjoy horns when filtered that way, as the acoustic aberrations produced when no attention is paid to proper summing are quite unpleasant.
I only enjoy horns when filtered that way, as the acoustic aberrations produced when no attention is paid to proper summing are quite unpleasant.
Eva said:
The bass drivers in the system are each powered by thier own 300w plate amp on the back of each cabinet, the plate amp are from BK electronics and have 360 degree variable phase and the crossover slope can be eq-ed from 12 to 24 db/octave. They have been modified to increase the maximum crossover frequency to match the midrange horn. The fe206e is currently running fullrange, but might get a highpass filter to reduce excursion.
This should allow the two drivers to be matched up pretty well
There is a very easy way to know if the drivers are matched or not. Use an A/B switch to swap the polarity of one of the drivers while you listen just in front of the two-way system (one channel only). Play with the crossovers until you get a very marked cancellation around 150Hz with one of the polarities. Then the other polarity will be the right one.
The system won't be properly aligned if this cancellation notch does not happen when using the wrong polarity.
You can use that technique to create the midbass hot-spot at any height from the floor you wish. Cancellation will conveniently happen for other radiation angles (sound going to floor and ceiling).
I own a three-way system made with PA tweeter and midrange horns and a folded bass horn, and it's quie hard to get that kind of hyp/exp horns to sum properly. Tracktrix profiles are supposed to produce a much smoother phase response in the lower cutoff region, though, thus making crossing over much easier.
The system won't be properly aligned if this cancellation notch does not happen when using the wrong polarity.
You can use that technique to create the midbass hot-spot at any height from the floor you wish. Cancellation will conveniently happen for other radiation angles (sound going to floor and ceiling).
I own a three-way system made with PA tweeter and midrange horns and a folded bass horn, and it's quie hard to get that kind of hyp/exp horns to sum properly. Tracktrix profiles are supposed to produce a much smoother phase response in the lower cutoff region, though, thus making crossing over much easier.
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