Enjoy. Well worth the outlay.
Re the different mouths, there's beauty in simplicity but it can be taken too far. The existing profile was quite carefully shaped. Bruce & Loreena's expansion for example has a parabolic section which smooths the response slightly. Your ideas are interesting though -you might want to try one out. Just be careful to get the flares right & ensure the correct degree of end correction, which they're currently somewhat out on.
Re the different mouths, there's beauty in simplicity but it can be taken too far. The existing profile was quite carefully shaped. Bruce & Loreena's expansion for example has a parabolic section which smooths the response slightly. Your ideas are interesting though -you might want to try one out. Just be careful to get the flares right & ensure the correct degree of end correction, which they're currently somewhat out on.
Glowbug said:Is there any performance difference between having the stepped horn mouth and doing the alternate? My gut tells me no, but then why would you have put that on the plans
The only affect the alternate should have is to save wood at the expense of having to make some cuts that aren't 90 degrees.
There is also the cosmetic consideration.
When we build Aiko we are going to do the 45s...
BTW: let me introduce the newest (& smallest Spawn family member -- daugher of Mikasa. For the Lyeco LY401F (this desigb qon Scott a pair over on the Full Range Forum) althou FE108eS should drop right in.
dave
Hi,
I am considering building myself some full-range speakers to replace my current 3-ways. I like the look of the tall double horns. I am a little confused about the way to choose drivers though. I understand from the "single driver website", http://www.melhuish.org/audio/horndriver.html, that the criteria for apropriate horn drivers is a low Qts (0.2 to 0.3), really low xMax, and a strong magnet (high Bl?). Fostex sigmas seem pretty good for this. I have noticed though that some of the drivers people are using in these horns dont have the properties I just described and are getting good results. How much do the measurements matter and what will give the best results with the BVR style horns?
Thanks for the help,
Mark
I am considering building myself some full-range speakers to replace my current 3-ways. I like the look of the tall double horns. I am a little confused about the way to choose drivers though. I understand from the "single driver website", http://www.melhuish.org/audio/horndriver.html, that the criteria for apropriate horn drivers is a low Qts (0.2 to 0.3), really low xMax, and a strong magnet (high Bl?). Fostex sigmas seem pretty good for this. I have noticed though that some of the drivers people are using in these horns dont have the properties I just described and are getting good results. How much do the measurements matter and what will give the best results with the BVR style horns?
Thanks for the help,
Mark
Hi Mark
Would that there were a simple answer. Frankly, within reason, you can use anything if you design the cabinet to suit it. Dave & I have done a BVR for the Visaton B200 for example (Oscar: v. similar to Loreena), which has a 0.7Qt and high 102 litre Vas).
Of course, the BVRs aren't like 'normal' horns (whatever that means) -in reality, like PA scoop-bins, they're reflex cabinets with, er, slightly larger than average vents. Of course, the presentation is rather different to the average BR box -they couple to a large quantity of air, just like other horns do, so their presentaion is very similar, although they can't go as loud without distorting. OTOH, many longer path designs have inherently higher ripple as they too are compromises (i.e. not 'real' horns, but hybrid QWRs / horns) and cranking them loud won't erradicate that, so in some cases you could arguably end up in a much of a muchness situation
As a rule, a nice mid-Q unit with moderate Vas is good for BVR loads, just as it would be for their more common, small vent-cousins, primarily because they're easy to work with, and you can keep the cabinet size reasonable.
For long path horns, a low Q is useful (although not mandatory) as you've got a powerful motor there, and ergo, potentially superior dynamics.
Hope some of that helps
Scott
Would that there were a simple answer. Frankly, within reason, you can use anything if you design the cabinet to suit it. Dave & I have done a BVR for the Visaton B200 for example (Oscar: v. similar to Loreena), which has a 0.7Qt and high 102 litre Vas).
Of course, the BVRs aren't like 'normal' horns (whatever that means) -in reality, like PA scoop-bins, they're reflex cabinets with, er, slightly larger than average vents.
Of course, the presentation is rather different to the average BR box -they couple to a large quantity of air, just like other horns do, so their presentaion is very similar, although they can't go as loud without distorting. OTOH, many longer path designs have inherently higher ripple as they too are compromises (i.e. not 'real' horns, but hybrid QWRs / horns) and cranking them loud won't erradicate that, so in some cases you could arguably end up in a much of a muchness situationAs a rule, a nice mid-Q unit with moderate Vas is good for BVR loads, just as it would be for their more common, small vent-cousins, primarily because they're easy to work with, and you can keep the cabinet size reasonable.
For long path horns, a low Q is useful (although not mandatory) as you've got a powerful motor there, and ergo, potentially superior dynamics.
Hope some of that helps
Scott
markgoespop said:
BVR stands for Big Vent Reflex (or as my buddy says BAVR), so they really need to be looked at as bass reflex when choosing a driver. This is why Fosex FExx7, Lyeco LY801 & Visaton B200 can work in these (and often better than the FExx6 brethern). You will note in the Harvey sims how the cabinet almost completely dominates the horn's performance -- we figure these should be pretty versatile.
Scott is better prepared to say how the Qts/Vas affects things.
dave
It's an interesting issue. Higher Q can actually allow a smoother response on occasion. Martin noted in one of his BLH papers that the resistive impedence of the horn can be quite effective at damping the high Q unit's ringing response. Of course, that's very much dependant on the design. But the trade-off is a reduction in dynamics, as Ron has described elsewhere.
FWIW, one of the things I've found working with pipe horns is that you can play off Q against Vas. Normally, high Vas demands a large box, but if the motor strength is sufficiently low, you can get away with a smaller Vb than you might expect. The opposite applies -high Q will work, if Vas is low. Low Vas, low Q is OK too. The nightmare is high Vas, high Q, which demands a downright monster of an enclosure. As a quick ROT, the same thing applies to hybrid QWR / horns, though I'm sure there are exceptions.
The BVRs OTOH, are relatively forgiving, as seen by the B200 cabinet we've done. More so than small vent reflex cabinets actually. If you can get sufficient Vb, the large vents appear to act as Martin describes above, and damp out the response. Generally mid Q, mid Vas make for an easier / more compact life and design though, just as they would for a smaller vent reflex cabinet.
BTW -Dave, did my emails get through OK this time? I'm going to try to shift over to the Frugal-horn address either this evening or tomorrow, if I can persuade my PC to play ball for once it its life... At the moment, hotmail appears to be down yet again, which is pretty much the last straw, and makes me wonder just how many of my emails over the past couple of days to different people have actually got through.
FWIW, one of the things I've found working with pipe horns is that you can play off Q against Vas. Normally, high Vas demands a large box, but if the motor strength is sufficiently low, you can get away with a smaller Vb than you might expect. The opposite applies -high Q will work, if Vas is low. Low Vas, low Q is OK too. The nightmare is high Vas, high Q, which demands a downright monster of an enclosure. As a quick ROT, the same thing applies to hybrid QWR / horns, though I'm sure there are exceptions.
The BVRs OTOH, are relatively forgiving, as seen by the B200 cabinet we've done. More so than small vent reflex cabinets actually. If you can get sufficient Vb, the large vents appear to act as Martin describes above, and damp out the response. Generally mid Q, mid Vas make for an easier / more compact life and design though, just as they would for a smaller vent reflex cabinet.
BTW -Dave, did my emails get through OK this time? I'm going to try to shift over to the Frugal-horn address either this evening or tomorrow, if I can persuade my PC to play ball for once it its life...
At the moment, hotmail appears to be down yet again, which is pretty much the last straw, and makes me wonder just how many of my emails over the past couple of days to different people have actually got through.
Pit
Cheap Drivers
Hello again,
Thanks for the responses Scottmoose and planet10, that makes good sense. I noticed the Replikon horn on the net and saw a few other examples of BVRs which has made me think that this is a decent way to design an enclosure.
I saw that "Bruce" can be made with a Monacor sp200x as well as fostex and Hemp Acoustics fr-8. I couldnt find a price on the Monacor's but the Hemp's I saw were $125 a piece, which wouldnt be the end of the world, although cheaper would be better at first.
I am thinking it would be good to build some Bruces and get some cheap drivers, then if they work and are promising I could drop in some nicer drivers. Do you have any suggestions for cheapish drivers that would work well for any of the BVRs especially Bruce?
Thanks again,
Mark
Hello again,
Thanks for the responses Scottmoose and planet10, that makes good sense. I noticed the Replikon horn on the net and saw a few other examples of BVRs which has made me think that this is a decent way to design an enclosure.
I saw that "Bruce" can be made with a Monacor sp200x as well as fostex and Hemp Acoustics fr-8. I couldnt find a price on the Monacor's but the Hemp's I saw were $125 a piece, which wouldnt be the end of the world, although cheaper would be better at first.
I am thinking it would be good to build some Bruces and get some cheap drivers, then if they work and are promising I could drop in some nicer drivers. Do you have any suggestions for cheapish drivers that would work well for any of the BVRs especially Bruce?
Thanks again,
Mark
You're welcome -glad to help when possible.
http://www.spectrumaudio.de/breit/monacor/monacorSP200X.html
Wolfgang is, so I hear, an all-round top-bloke. And look at that response. Nice & flat, although it'll probably need a super-tweeter up-top.
http://www.spectrumaudio.de/breit/monacor/monacorSP200X.html
Wolfgang is, so I hear, an all-round top-bloke. And look at that response. Nice & flat, although it'll probably need a super-tweeter up-top.
Yay, just finished the new platform bed and now it's on to bigger and better things. The BRUCE!! (BTW thanks for naming it Bruce, made it a whole lot easier to sell it to the girlfriend)
I had two quick questions.
1. Could the Pioneer BUFU20 be used in this design?? At 1/3 the price of the Fostex 207 it could be a good savings. But, if it would reduce performance too much, it wouldn't be worth it.
2. The little wedge/absorbent strip at the throat. Does anyone have experience or thoughts on which may be better?
Thanks,
Bruce
I had two quick questions.
1. Could the Pioneer BUFU20 be used in this design?? At 1/3 the price of the Fostex 207 it could be a good savings. But, if it would reduce performance too much, it wouldn't be worth it.
2. The little wedge/absorbent strip at the throat. Does anyone have experience or thoughts on which may be better?
Thanks,
Bruce
Hi Bruce
Er, Bruce shouldn't need the absorbant strip as it's vents operate over a much more limited passbad -they cut off just over 100Hz or so, so the output shouldn't need damping.
The Pioneer is supposed to be a good unit for the money, but it's far behind the 207. I'd go with the Fostex.
If you're wondering where the name came from, it's actually named after the metal singer & Iron Maiden front-man Bruce Dickinson, who I've always greatly admired. Pity his albums are so badly recorded as musically they're actually pretty special.
Er, Bruce shouldn't need the absorbant strip as it's vents operate over a much more limited passbad -they cut off just over 100Hz or so, so the output shouldn't need damping.
The Pioneer is supposed to be a good unit for the money, but it's far behind the 207. I'd go with the Fostex.
If you're wondering where the name came from, it's actually named after the metal singer & Iron Maiden front-man Bruce Dickinson, who I've always greatly admired. Pity his albums are so badly recorded as musically they're actually pretty special.
Driver Placement
Hello everyone,
I am looking forward to getting some time and money so I can start building, for now I have to wait... I was just wondering one thing about Bruce. I think I saw either Scott or Dave said that driver placement was important with these cabinets. Would there be any negative effects to dropping the driver to the bottom of the speaker baffle about a half inch shy of the bottom edge to leave space on the baffle for a super-tweeter (I have my eye on the smallest Aurum Cantus ribbon)? I could see how breaking the vertical symetry might unbalance the use of the throats at the back. Any ideas?
Thanks,
Mark
Hello everyone,
I am looking forward to getting some time and money so I can start building, for now I have to wait... I was just wondering one thing about Bruce. I think I saw either Scott or Dave said that driver placement was important with these cabinets. Would there be any negative effects to dropping the driver to the bottom of the speaker baffle about a half inch shy of the bottom edge to leave space on the baffle for a super-tweeter (I have my eye on the smallest Aurum Cantus ribbon)? I could see how breaking the vertical symetry might unbalance the use of the throats at the back. Any ideas?
Thanks,
Mark
In addition to the iBIB(possibly k) for my 206's, I am going to start making a pair of Harveys for the 126's I just got today (thanks planet 10, these are awesome!).
I've heard rumor that the double horns may one day be remodelled with non-symetrical horns to even out the FR a bit. I was wondering if raising the whole chambered part (all else remaining the same) about an inch or so may have this effect, or if it requires a complete redesign and I'm best to leave it alone.
This would result in two very close but not quite equal horns, the top one would be about 2 inches shorter and a few square inches less mouth area. This speaker is intended to perform well in a variety of environments, so tailoring a specific FR is pointless, but flat is probably desireable.
I would assume that the slightly larger, floor loaded bottom horn would dominate, but past that I have no predictions on what would actually happen.
I don't intend anyone to waste time modelling this idea, and if it's a bad idea I'm happy to stick to the plans. Just wondering.
I've heard rumor that the double horns may one day be remodelled with non-symetrical horns to even out the FR a bit. I was wondering if raising the whole chambered part (all else remaining the same) about an inch or so may have this effect, or if it requires a complete redesign and I'm best to leave it alone.
This would result in two very close but not quite equal horns, the top one would be about 2 inches shorter and a few square inches less mouth area. This speaker is intended to perform well in a variety of environments, so tailoring a specific FR is pointless, but flat is probably desireable.
I would assume that the slightly larger, floor loaded bottom horn would dominate, but past that I have no predictions on what would actually happen.
I don't intend anyone to waste time modelling this idea, and if it's a bad idea I'm happy to stick to the plans. Just wondering.