Indeed. If I were doing one specifically for the 108, then I'd probably reduce chamber volume a trifle, but it shouldn't be too critical -there are a pair with 108s here that have very positive feedback. Like Frugelhorn, this is an open-source project, so builders: please report back your personal experiences and modifications.
Harderror: without actually having the specific data you entered, it's difficult to say to be honest. If you want to PM me, I'll be glad to take a look at the design and see if I can make any suggestions. FWIW, I reckon you're about right with your guessed cut-off point being around 37Hz or so. Also -MathCad can't tell us everything, just a lot of things; that's where prior experience comes in.
Harderror: without actually having the specific data you entered, it's difficult to say to be honest. If you want to PM me, I'll be glad to take a look at the design and see if I can make any suggestions. FWIW, I reckon you're about right with your guessed cut-off point being around 37Hz or so. Also -MathCad can't tell us everything, just a lot of things; that's where prior experience comes in.
Thanks Dave, Scott for the reply re: the horn. Has anyone noticed the bracing in the mouth to have an effect. Would these act as a mini reflector ? Most horns I hear midrange also coming out of the back horn, this has never bothered me but these being short horns, do these also put out midrange or does the cc slot filter this out? Is the response good to 80hz?
Going to use 19mm poplar ply from Windsor Plywood. Some say that sonically fir is good but the grain is not that appealing to finish.
thanks
doggy
Going to use 19mm poplar ply from Windsor Plywood. Some say that sonically fir is good but the grain is not that appealing to finish.
thanks
doggy
The horns don't produce much above 120Hz, so midrange leakage shouldn't be a problem for you. It's also why they have very little response ripple. They're best viewed in theoretical terms as reflex boxes with huge vents coupling to extremely large quantities of air. So although sonically they sound like horns (big, effortless presentation) they don't behave in quite the same way electrically as most domestic horns do. With FE126E, fed by a good amp, they're solid to 40Hz. 80Hz = no problem at all.
horn questions
Some horn questions:
I see there is a long path fe108ez horn design. The bvr horn is described as "a big sound" with bass to 40 hz. So what presentation would you expect from the long path horn? what is the penalty for lower bass? It will be interesting to compare them, from the listening aspect.
Is the length of the bass horn path critical to low output? What is the result of a horn path that is 1/2 the long path length ?some where in the middle?
Just asking for some subjective opinions
I also will like to try a long vertical front horn with a reflector, the back wave into a bass reflex, as an experiment.[no more beaming?]
Some horn questions:
I see there is a long path fe108ez horn design. The bvr horn is described as "a big sound" with bass to 40 hz. So what presentation would you expect from the long path horn? what is the penalty for lower bass? It will be interesting to compare them, from the listening aspect.
Is the length of the bass horn path critical to low output? What is the result of a horn path that is 1/2 the long path length ?some where in the middle?
Just asking for some subjective opinions
I also will like to try a long vertical front horn with a reflector, the back wave into a bass reflex, as an experiment.[no more beaming?]
Attachments
Actually, I doubt they will go much, if any lower at all. But they'll certainly sound very different.
The two designs work on different principles. The short horn types are basically reflex boxes with extremely large vents -what GM calls a Big Vent Reflex (BVR). They don't sound like reflex boxes of course (about as far removed as you're likely to get actually), but they operate like them electrically speaking.
The long path design operates on the more usually seen hybrid quarter-wave / horn loading principle. I've added a twist to this by adopting the stepped Nagaoka style of design, which has much to commend it -an expanding cascade of straight half-wave resonators. It's more efficient, and the horns operate higher -in the BVR type, the horns cut off at around 100Hz; in the longer type, they go about twice as high.
Bass extension depends upon what sort of loading you're getting. In a 'proper' horn, it is dependant upon mouth circumference, and the amount of gain you get upon the length and throat CSA. But there's only a couple of proper horns out there -the Kleinhorn for example. They need to be roughly the size of R.M.S. Titanic to get decent LF performance, even when wall, floor or corner-loaded.
All the rest are hybrid QW / horns, or BVRs. In the hybrids, like the most recent design here, it's dependent upon a mixture of length and area ratio, rather like like an expanding QWR. With these, it's best to make sure line length is a minimum of 1/4 the target Fc (cut off frequency), and preferably more: 1/2 wavelength of Fc is ideal.
The BVRs simply operate like reflex boxes with huge vents -as you know with vents, the larger a radius, the longer it needs to be. Especially if tapered. The flare is chosen for minimum distortion. They're basically waveguides. So are the others, but the effect is more extreme for the BVRs due to the shortness of the path. For low excursion drivers, the longer types offer superior control over the driver and lower distortion at high SPLs, but it's rather situation dependent.
That's my take on it anyway. It's far more complicated than that, as you start bringing more advanced QW theory into the mix, or even approach the hybrid types from a completely different angle, and look at them from a pressure, rather than a vibration perspective, like huge compression horn variations, but it's my whistle-stop tour anyway.
Best
Scott
The two designs work on different principles. The short horn types are basically reflex boxes with extremely large vents -what GM calls a Big Vent Reflex (BVR). They don't sound like reflex boxes of course (about as far removed as you're likely to get actually), but they operate like them electrically speaking.
The long path design operates on the more usually seen hybrid quarter-wave / horn loading principle. I've added a twist to this by adopting the stepped Nagaoka style of design, which has much to commend it -an expanding cascade of straight half-wave resonators. It's more efficient, and the horns operate higher -in the BVR type, the horns cut off at around 100Hz; in the longer type, they go about twice as high.
Bass extension depends upon what sort of loading you're getting. In a 'proper' horn, it is dependant upon mouth circumference, and the amount of gain you get upon the length and throat CSA. But there's only a couple of proper horns out there -the Kleinhorn for example. They need to be roughly the size of R.M.S. Titanic to get decent LF performance, even when wall, floor or corner-loaded.
All the rest are hybrid QW / horns, or BVRs. In the hybrids, like the most recent design here, it's dependent upon a mixture of length and area ratio, rather like like an expanding QWR. With these, it's best to make sure line length is a minimum of 1/4 the target Fc (cut off frequency), and preferably more: 1/2 wavelength of Fc is ideal.
The BVRs simply operate like reflex boxes with huge vents -as you know with vents, the larger a radius, the longer it needs to be. Especially if tapered. The flare is chosen for minimum distortion. They're basically waveguides. So are the others, but the effect is more extreme for the BVRs due to the shortness of the path. For low excursion drivers, the longer types offer superior control over the driver and lower distortion at high SPLs, but it's rather situation dependent.
That's my take on it anyway. It's far more complicated than that, as you start bringing more advanced QW theory into the mix, or even approach the hybrid types from a completely different angle, and look at them from a pressure, rather than a vibration perspective, like huge compression horn variations, but it's my whistle-stop tour anyway.
Best
Scott
Generators, yes... my alt energy guy recommends a Honda. And another has a surplus 4.8k unit.... we don't have heat problems since we heat by wood. (at least the storm provided for next years heating, and hopefully enuff timber to frame in the greenhouse on the south side of the house)
BC Hyro spent at least 16 hrs in front of our house fixing the damage i mentioned previously. I talked with one of the guys -- he said he was dragging a bit from 16 16hr shifts in a row
I went up and had a close look at the fallen trees today. Amazing. I'll see if i can get some pics.
dave
BC Hyro spent at least 16 hrs in front of our house fixing the damage i mentioned previously. I talked with one of the guys -- he said he was dragging a bit from 16 16hr shifts in a row
I went up and had a close look at the fallen trees today. Amazing. I'll see if i can get some pics.
dave
Dave,
Yesterday I drove up past China beach to a hidden trail I know of that connects down to Chin beach on the Juan De Fuca Marine Trail. From my place to the trail head is approx 72km and from what I saw the damage to all the power and phone lines is huge.
BC Hydro was out in full force working all along Sooke Rd and the West Coast Rd, but man they have alot of wires and poles to fix. In one area there was about 1km of wires down in a row, I couldn't believe it. There are area's still where trees are leaning over the road and many,many spots all along that 72km drive where wires are down and trees and big branches need to be cleared before you can even get to the wires etc.
To think that is just one route of many areas affected is amazing, those guys have tons of work ahead of them that's for sure. Dave
Yesterday I drove up past China beach to a hidden trail I know of that connects down to Chin beach on the Juan De Fuca Marine Trail. From my place to the trail head is approx 72km and from what I saw the damage to all the power and phone lines is huge.
BC Hydro was out in full force working all along Sooke Rd and the West Coast Rd, but man they have alot of wires and poles to fix. In one area there was about 1km of wires down in a row, I couldn't believe it. There are area's still where trees are leaning over the road and many,many spots all along that 72km drive where wires are down and trees and big branches need to be cleared before you can even get to the wires etc.
To think that is just one route of many areas affected is amazing, those guys have tons of work ahead of them that's for sure. Dave
Dave & Dave:
as I quoted from the Times Colonist during the last power outage ( Dec 2nd)
"Vancouver Island has the highest tree count per kilometer of utility lines of any location in North America"
In combination with record rainfalls in many areas, it looks like each of these major blows weakens not only the branches of trees, but the shallow root systems of major/old growths. Check out the damage at Stanley Park.
I guess we can be thankful for the barely warm enough temperatures that prevented more of that sloppy heavy wet snow responsible for most of the broken branches last time. One of the chaps at work lives on Triangle Mountain - was dark for over 8 days last time, and the brand new transformer blowed up good again - as well as half his roof and other major structural damage.
A generator would still be a very good idea for the mountain.
On a happier note - Frank has completed his 206ESR horns over the weekend, and we should arrange for a listen during X-mas break.
as I quoted from the Times Colonist during the last power outage ( Dec 2nd)
"Vancouver Island has the highest tree count per kilometer of utility lines of any location in North America"
In combination with record rainfalls in many areas, it looks like each of these major blows weakens not only the branches of trees, but the shallow root systems of major/old growths. Check out the damage at Stanley Park.
I guess we can be thankful for the barely warm enough temperatures that prevented more of that sloppy heavy wet snow responsible for most of the broken branches last time. One of the chaps at work lives on Triangle Mountain - was dark for over 8 days last time, and the brand new transformer blowed up good again - as well as half his roof and other major structural damage.
A generator would still be a very good idea for the mountain.
On a happier note - Frank has completed his 206ESR horns over the weekend, and we should arrange for a listen during X-mas break.
