Cal,
I was thinking ( asking myself) the same thing so it may complicate the reverse engineering unless one uses a model like AkAbak which can handle tapered ports in a bass reflex. It is clever to do that because it essentially makes the port longer than its physical length. The Egg speaker looks very nicely engineered that I would not have had the heart to cannibalize it like this.
I was thinking ( asking myself) the same thing so it may complicate the reverse engineering unless one uses a model like AkAbak which can handle tapered ports in a bass reflex. It is clever to do that because it essentially makes the port longer than its physical length. The Egg speaker looks very nicely engineered that I would not have had the heart to cannibalize it like this.
Am not overly struck by the Cormu...... will see though
Do it the way I did and you'll get all you need as far as satisfaction is concerned. No other speaker I have built has the same ***** and giggles factor. They're not for critical listening but the bass they kick out makes them suitable even for an outdoor party. If you take the time to make them right you'll not be sorry. I have a high WAF set of speakers in less than 20 hours. Speaking of WAF, she can carry both speakers at once. That's another first for me.
I have to agree with Cal on this one. You will get some real satisfaction from the sound of the Cornu's which I might describe as 'flamboyant' and 'fun'. Also, I know of no other BLH that is so forgiving with what driver you stick in it as long as approximate size scale is good. Having high WAF and lightweight where the wife can pick up both speakers with one hand is different.
Foam board construction
A thought how to cheaply make foam board construction more ridged.
Use two layers of board with some thin vertical spacers between.
Blow in some foam between the channels with a can of insulation expanding foam.
The resulting board should be very stiff. Might be useful if someone builds a full sized
TH sub, or karlson with a large driver.
A thought how to cheaply make foam board construction more ridged.
Use two layers of board with some thin vertical spacers between.
Blow in some foam between the channels with a can of insulation expanding foam.
The resulting board should be very stiff. Might be useful if someone builds a full sized
TH sub, or karlson with a large driver.
That is fine for large rectangular panels like the sides but what about smaller interior pieces? It becomes very labor intensive to do that. Many times it is sufficient to double or triple the wall thickness. Or use 1 in thick xps foam sheathing from HD or Lowes. I find using the higher quality Elmers fc board is substantially stronger and stiffer.
Well, I finally managed to find the time to phone Kef
After a brief explanation of 'things' to the Very sweet lady on the main desk, she put me through to the 'Tech Department' front of house.
After explaining things to the gent on the other end, he said there will be not trouble with getting 'All the specs I can lay my hands on from the R&D guys' for the 'egg' enclosure / drive unit / cross-over quoted......
"Unfortunately Mr.Woodward, you might have to give me a week to ten days as we have suffered flooding, the whole of our site was under 2 1/2 ft of water over Christmas and the guys down there are busy cleaning not designing"
I also outlined my thoughts about a DIY implementation......
"Ooooh, that sounds like a lot of fun, I'm sure if I ask the guys nicely they will be able to give you some support with this as we all like fun things - Send me an email with your ideas etc and we will see what we can do to help with your project."
I told the gent that If I was situated closer, I would be banging on the door to offer my help as a volunteer pushing a broom etc.
"That's a very generous offer Sir, we have broken the back of the work, but if your ever in our locale, please give me a call and I will give you a tour of the factory."
Regards the Cormu - GF says NO..... first time in three years she's been emphatic about 'audio'!
Regards my projects direction - It Will have a foam enclosure, with some wood and maybe some Carbon fiber.......
After a brief explanation of 'things' to the Very sweet lady on the main desk, she put me through to the 'Tech Department' front of house.
After explaining things to the gent on the other end, he said there will be not trouble with getting 'All the specs I can lay my hands on from the R&D guys' for the 'egg' enclosure / drive unit / cross-over quoted......
"Unfortunately Mr.Woodward, you might have to give me a week to ten days as we have suffered flooding, the whole of our site was under 2 1/2 ft of water over Christmas and the guys down there are busy cleaning not designing"
I also outlined my thoughts about a DIY implementation......
"Ooooh, that sounds like a lot of fun, I'm sure if I ask the guys nicely they will be able to give you some support with this as we all like fun things - Send me an email with your ideas etc and we will see what we can do to help with your project."
I told the gent that If I was situated closer, I would be banging on the door to offer my help as a volunteer pushing a broom etc.
"That's a very generous offer Sir, we have broken the back of the work, but if your ever in our locale, please give me a call and I will give you a tour of the factory."
Regards the Cormu - GF says NO..... first time in three years she's been emphatic about 'audio'!
Regards my projects direction - It Will have a foam enclosure, with some wood and maybe some Carbon fiber.......
She says they are too square.
She likes big box speakers as long as they sound good.
She has my Time Trial bike hung on our bedroom wall because she likes to look at it, she gives all sorts of reasons when asked about it being there, one being that it has 'interesting shadows'.
I look at it and see sweat, pain and oxygen dep.
Clea's a great lass
I use to be big into Aeromodeling - 2.5cc Control Line race classes, the skills I learnt skinning racers with Epoxy and silk, GF and CF went into making surfboards - which I now make money from.
The place I will get my foam from makes surfboard blanks, when they were developing their 'Bio Foam', I was one of the guys who got 'experimental mix' blanks to test
The foam I will be using is not cheap even to me, but on odd occasions, the boss helps some fall into my car.
The project has to be interesting for this to happen, this is one of those projects.
Linky time
High density foam HD65 HD80 HD120 HD200 - o0O° Welcome to Homeblown UK °O0ox1
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Sippy,
She does sound like a great gal if she likes staring at a bike on a wall. I used to hang my 17 lb Vitus with sewups on a wall just to admire it too.
If you want a fancy foam, check out polymer cross linked aerogels. Super strong, weigh nothing - literally feels like air.
NASA researchers replace silica with polymers to create more flexible aerogels
She does sound like a great gal if she likes staring at a bike on a wall. I used to hang my 17 lb Vitus with sewups on a wall just to admire it too.
If you want a fancy foam, check out polymer cross linked aerogels. Super strong, weigh nothing - literally feels like air.
NASA researchers replace silica with polymers to create more flexible aerogels
Been reading this thread and started to look at youtube clips... these guys have some excellent tips and techniques which are not speakers but may enable some people some pointers to apply to speaker builds.
House models...
Foam Board Model Making Architectural House Scale Design Part 3 - YouTube
These guys build air planes.. this Spitfire build looks great... The wood sticks may be useful for aligning layers of enclosure.
Flite Test - FT Spitfire - BUILD - YouTube
PS in the UK hobbycraft shop do 3 for 2 on a 5mm A1 sheets for £4 a sheet so 3 A1 sheets for £8 I think this is about as cheap as I could find in the UK.
Tools> http://www.youtube.com/watch?v=BefKPhQCuB8
Maybe useful for smaller speakers up to 6 inches >
http://www.ebay.co.uk/itm/WA8001-Fo..._Crafts_FramingMatting_EH&hash=item35cfbe2e07
http://www.youtube.com/watch?v=gEZuLRp6YQ8
House models...
Foam Board Model Making Architectural House Scale Design Part 3 - YouTube
These guys build air planes.. this Spitfire build looks great... The wood sticks may be useful for aligning layers of enclosure.
Flite Test - FT Spitfire - BUILD - YouTube
PS in the UK hobbycraft shop do 3 for 2 on a 5mm A1 sheets for £4 a sheet so 3 A1 sheets for £8
I think this is about as cheap as I could find in the UK.Tools> http://www.youtube.com/watch?v=BefKPhQCuB8
Maybe useful for smaller speakers up to 6 inches >
http://www.ebay.co.uk/itm/WA8001-Fo..._Crafts_FramingMatting_EH&hash=item35cfbe2e07
http://www.youtube.com/watch?v=gEZuLRp6YQ8
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Thanks for the link to RC planes - I always thought this stuff is light and stiff making it ideal for planes. One can attach those stick on exciter transducers to the foam wing and power it with a small class D amp so that the plane can play music (or simulated 2 stroke engine screaming noises) as it flies - these all electric planes don't have the cool sound of 2 stroke engines running on nitromethane and castor oil like the good old days of RC flying.
The problem with foam core is that it flexes if unsupported. Flat-sided designs in foam core need a lot of bracing. This is not a problem with enclosure designs such as the Cornu or the Nautaloss, where the curved sections add rigidity. Curving a panel is difficult with wood but easy with foam core. So why not make an enclosure with an elliptical cross section, with one curved piece of foam core forming the sides and back?
X, I decided to get back into speaker building a few weeks ago after a 25 year hiatus. After a bunch of internet searching I landed on Zaph’s site and thought I’d get a few HiVi B3Ns (I bought 4) as a way to ease back into things – small full range and cheap, so no biggie if the results weren’t good. I started with a standard sealed box of 3 liter and I must say that I was somewhat underwhelmed – sound quality was okay, but just not enough of it. Gee, they are terribly inefficient little blighters!
Luckily, I then stumbled into the foam core thread and after a full week of reading enjoyment decided to give the Cornus a go. Well, I’m so glad I did. I managed to finish them in a day and a half and the result was fantastic. I have them on the wall at my chalet and they create what can only be described as, and my apologies for being so Corny, “a wall of sound”. I’ve since matched them with a sub that I transplanted from a JVC HTIB sub, which I got from Goodwill, into a nice solid sealed Orion box (old Hungarian brand). I now have both the sound quality and quantity I was hoping for. So, thanks very much for starting and pushing this thread along.
I’ve since tried a TL foam core for the other two B3Ns using this design (file:///C:/Users/hp/Desktop/Speaker%20project/B3N%20TL/u-B3N.htm) and I must say I’m somewhat underwhelmed again. They sound “small” in comparison to the Cornus. So, a question for you please – which of your other designs would you suggest for the B3Ns? I like the “big” sound of the Cornus, but would like to try something different – I could again mate them with a sub.
Cheers!
PS I just love the concept of being able to knock together an enclosure in quick time that doesn’t require a shop full of wood-working tools. It’s a winner!
Luckily, I then stumbled into the foam core thread and after a full week of reading enjoyment decided to give the Cornus a go. Well, I’m so glad I did. I managed to finish them in a day and a half and the result was fantastic. I have them on the wall at my chalet and they create what can only be described as, and my apologies for being so Corny, “a wall of sound”. I’ve since matched them with a sub that I transplanted from a JVC HTIB sub, which I got from Goodwill, into a nice solid sealed Orion box (old Hungarian brand). I now have both the sound quality and quantity I was hoping for. So, thanks very much for starting and pushing this thread along.
I’ve since tried a TL foam core for the other two B3Ns using this design (file:///C:/Users/hp/Desktop/Speaker%20project/B3N%20TL/u-B3N.htm) and I must say I’m somewhat underwhelmed again. They sound “small” in comparison to the Cornus. So, a question for you please – which of your other designs would you suggest for the B3Ns? I like the “big” sound of the Cornus, but would like to try something different – I could again mate them with a sub.
Cheers!
PS I just love the concept of being able to knock together an enclosure in quick time that doesn’t require a shop full of wood-working tools. It’s a winner!
Grandcalmar,
I am so glad the Cornu's worked out for you so well.
Those HiVi B3N's really are low efficiency drivers at 81dB. I think that is a large part of why you are underwhelmed. A good cure for that if the drivers are 8 ohms is to double them up. Good thing you have four of them as what I suggest is a mini Karlsonator with dual drivers. Doubling up an 8 ohm driver in parallel to 4 ohms will give you +6dB (4 times louder) at the same voltage. So you will have 87dB at 2.83v speakers. I will post the sims and design details in the mini Karlsonator thread: http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-41.html#post3803617
Basically, you will get a speaker with bass in the 90+ dB that extends to sub 50 Hz. The highs will be at about 87dB and you will have built-in baffle step compensation due to all the bass gain. It looks like a great candidate.
Cheers,
X
I am so glad the Cornu's worked out for you so well.
Those HiVi B3N's really are low efficiency drivers at 81dB. I think that is a large part of why you are underwhelmed. A good cure for that if the drivers are 8 ohms is to double them up. Good thing you have four of them as what I suggest is a mini Karlsonator with dual drivers. Doubling up an 8 ohm driver in parallel to 4 ohms will give you +6dB (4 times louder) at the same voltage. So you will have 87dB at 2.83v speakers. I will post the sims and design details in the mini Karlsonator thread: http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-41.html#post3803617
Basically, you will get a speaker with bass in the 90+ dB that extends to sub 50 Hz. The highs will be at about 87dB and you will have built-in baffle step compensation due to all the bass gain. It looks like a great candidate.
Cheers,
X
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Don, I like the concept - curving to get rigidity, but having trouble visualizing the shape. No trouble with one "one curved piece forming the sides", but how can that same piece also form the back? Are you thinking of a shape like a clam (shellfish) with flat front for the baffle?
Cheers
Grandcalmar,
I am so glad the Cornu's worked out for you so well.
Those HiVi B3N's really are low efficiency drivers at 81dB. I think that is a large part of why you are underwhelmed. A good cure for that if the drivers are 8 ohms is to double them up. Good thing you have four of them as what I suggest is a mini Karlsonator with dual drivers. Doubling up an 8 ohm driver in parallel to 4 ohms will give you +6dB (4 times louder) at the same voltage. So you will have 87dB at 2.83v speakers. I will post the sims and design details in the mini Karlsonator thread: http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
Basically, you will get a speaker with bass in the 90+ dB that extends to sub 50 Hz. The highs will be at about 87dB and you will have built-in baffle step compensation due to all the bass gain. It looks like a great candidate.
Cheers,
X
Thanks X, I'll check the Karlsonator thread. I'm sure I'm not the only "noob" drawn to the B3Ns by Zaph's site only then to be disappointed due to their low efficiency.
Zaph is a great designer and I imagine that if you push enough power through those speakers they will sound good . An 81 dB efficient speaker will lose several dB of sensitivity when a passive crossover is used so it is probably in the high 70's per watt. That means that you will have to be pushing them at 10 watts or more to really feel satisfying mid 80 dB's.
. An 81 dB efficient speaker will lose several dB of sensitivity when a passive crossover is used so it is probably in the high 70's per watt. That means that you will have to be pushing them at 10 watts or more to really feel satisfying mid 80 dB's.My wife said she was tired of the floor standing speakers, so could I please make a wall mounted one?
http://www.esa.int/var/esa/storage/...uropean_Acoustic_Facility_node_full_image.jpg
(really making a large pair of Cornu and a pair of 16X27FIBs right now.)
Here are a couple links showing what that huge horn is.
This Insanely Loud Sound System Simulates the Roar of a Rocket Launch
Space in Images - 2014 - 01 - Large European Acoustic Facility
http://www.esa.int/var/esa/storage/...uropean_Acoustic_Facility_node_full_image.jpg
(really making a large pair of Cornu and a pair of 16X27FIBs right now.)
Here are a couple links showing what that huge horn is.
This Insanely Loud Sound System Simulates the Roar of a Rocket Launch
Space in Images - 2014 - 01 - Large European Acoustic Facility
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NASA has a bigger and better one: RATF in Ohio does 163 dB and is bigger (1800 sq ft x 57 ft tall)
Space Power Facility (SPF)
Look at how many horns there are and the size of the mouths.
This is cool but what does it have to do with foam core?
Space Power Facility (SPF)
Look at how many horns there are and the size of the mouths.
An externally hosted image should be here but it was not working when we last tested it.
This is cool but what does it have to do with foam core?