Hey all,
I am preparing to start building a sound system over the course of the next year. I have been doing a lot of research and searching on folded horns and i have yet to find a good source of relevant info. I have read that in certian cases the folded horns require a large distance to develop a wavefront. If anyone can shed any light on this for me that would be great. I am looking into building a set of horns, either 2 dual 18 and 2 dual 12 boxes or 2 dual 21 and 2 dual 15 boxes. I have been planning this arrangement to facilitate high spl's and lower distortion. I want to use this system in a variety of locations, mid to large rooms (larger auditoriums) and outdoors. Any input and advice would be greatly appreciated, I you have another route that might be more suitable please let me know. The mid/high cabinets i am going to construct are single 12" mids in a horn system and a pair of compression drivers.
Thanks in advance
I am preparing to start building a sound system over the course of the next year. I have been doing a lot of research and searching on folded horns and i have yet to find a good source of relevant info. I have read that in certian cases the folded horns require a large distance to develop a wavefront. If anyone can shed any light on this for me that would be great. I am looking into building a set of horns, either 2 dual 18 and 2 dual 12 boxes or 2 dual 21 and 2 dual 15 boxes. I have been planning this arrangement to facilitate high spl's and lower distortion. I want to use this system in a variety of locations, mid to large rooms (larger auditoriums) and outdoors. Any input and advice would be greatly appreciated, I you have another route that might be more suitable please let me know. The mid/high cabinets i am going to construct are single 12" mids in a horn system and a pair of compression drivers.
Thanks in advance
Why not build 2x2 single 18"? In most cases it would offer more advantages and your back would be happier. One 12" to keep up with 2 hornloaded 18" would probably offer only very narow dispersion. Personally would double it.
A visit to www.speakerplans.com would help out, as it's more related to hornloaded and PA and it offers some very nice designs (1850 and 186 horn and tops).
Mvg Johan
A visit to www.speakerplans.com would help out, as it's more related to hornloaded and PA and it offers some very nice designs (1850 and 186 horn and tops).
Mvg Johan
Hi,
yes, have a look at Labhorn and particularly Tom Danley's treatise.
I liked his concluding comparison between his twin 12" horn cabinets and an IDEAL ported set of cabinets to produce similar SPL at similar frequencies. One set of horns is equivalent to 10 times as much power into 5 times (or did it say 10 times?) as many 18 inch speakers. At considerable extra cost and weight and volume (my words).
yes, have a look at Labhorn and particularly Tom Danley's treatise.
I liked his concluding comparison between his twin 12" horn cabinets and an IDEAL ported set of cabinets to produce similar SPL at similar frequencies. One set of horns is equivalent to 10 times as much power into 5 times (or did it say 10 times?) as many 18 inch speakers. At considerable extra cost and weight and volume (my words).
Andrew, that sounds like a bit of an exaggeration!
Ok so lets say we have one horn loaded 18 driven by 1kw to get max SPL. You are saying that it is equivalent to 10kw driving 5 or 10 of these drivers in a vented design?
That would be about 30db extra output gained through horn loading
Horn experts: how much extra juice (power and efficiency) do you get out of horn loading?
Expert Not
Typically there is a 10 db efficiency gain when a driver is properly horn loaded.
In terms of input power about 8 times less for equal loudness compared to a direct radiator.
Figure it like this. Every 3 db is a doubling or halving of power input. So every 3 db of efficiency gained allows a halving of input power from the amp to produce the same SPL.
As a side note most people percieve something as being twice as loud when it is actually 10 db louder than before.
So horn loading is going to get you louder.
This is true for only the passband of the horn. Above and below it acts much like a direct radiator. The efficiency gain is out the window. Below the low end cutoff of the horn it behaves like a ported box. The driver will flap wildly and most often destructively.
All this wonderfull volume at the expense of room volume
Mark
Typically there is a 10 db efficiency gain when a driver is properly horn loaded.
In terms of input power about 8 times less for equal loudness compared to a direct radiator.
Figure it like this. Every 3 db is a doubling or halving of power input. So every 3 db of efficiency gained allows a halving of input power from the amp to produce the same SPL.
As a side note most people percieve something as being twice as loud when it is actually 10 db louder than before.
So horn loading is going to get you louder.
This is true for only the passband of the horn. Above and below it acts much like a direct radiator. The efficiency gain is out the window. Below the low end cutoff of the horn it behaves like a ported box. The driver will flap wildly and most often destructively.
All this wonderfull volume at the expense of room volume
Mark
Hi all,
I did not claim the ten fold decrease in power. I was repeating what Tom Danley found out.
By the way 30db is one thousand fold decrease in power. Neither Tom Danley nor my reference to his work claimed that.
I too echo Mark's reply i.e. +10db improvement in efficiency for horn loading seems to be the norm.
Now go and read Labhorn and you'll find that it was designed for both in room and outdoor narrow band (30Hz to 80Hz) bass reproduction.
I did not claim the ten fold decrease in power. I was repeating what Tom Danley found out.
By the way 30db is one thousand fold decrease in power. Neither Tom Danley nor my reference to his work claimed that.
I too echo Mark's reply i.e. +10db improvement in efficiency for horn loading seems to be the norm.
Now go and read Labhorn and you'll find that it was designed for both in room and outdoor narrow band (30Hz to 80Hz) bass reproduction.
Just remember though that the labs were designed to be in stacks of six. That is to reach the required mouth area to get good output at 30hz. However a friend of mine only has a four stack and says it's all he can handle. Also, speakerplans.com has alot of DIY plans. I've built some and they are pretty good. Robert.
That business about horns not working in rooms is probably due to room modes and folklore. EAW does have a technical issue however with DR vs horn / distance see prosoundweb.com 'labhorn forum'
I dont see labhorns as being that useful in this case - complex,expensive,most the time 45hz extension is plenty.
Dont mix the basshorns with direct radiators in same range.
Youl need a stack of basshorns and delay your mains if the path length is long enough[or physically offset them]
Some on axis increase in SPL also due to large mouth can be helpful.
Its no use going horn and building half the required units though.
It sounds like an 1850 stack www.speakerplans.com
Or tuba or WSX type will do[plans are about,this is diyaudio after all] -Two WSX are great fun in a tiny club<100ppl
http://www.martin-audio.com/tourandprof/wsx.html
Whats real fun with hornloaded is making 85dB/1watt drivesr into 105db on a massive horn
The Worlds Largest Basshorns
http://www.geocities.com/xobt/basshorns/basshorns.htm
I dont see labhorns as being that useful in this case - complex,expensive,most the time 45hz extension is plenty.
Dont mix the basshorns with direct radiators in same range.
Youl need a stack of basshorns and delay your mains if the path length is long enough[or physically offset them]
Some on axis increase in SPL also due to large mouth can be helpful.
Its no use going horn and building half the required units though.
It sounds like an 1850 stack www.speakerplans.com
Or tuba or WSX type will do[plans are about,this is diyaudio after all] -Two WSX are great fun in a tiny club<100ppl
http://www.martin-audio.com/tourandprof/wsx.html
Whats real fun with hornloaded is making 85dB/1watt drivesr into 105db on a massive horn
The Worlds Largest Basshorns
http://www.geocities.com/xobt/basshorns/basshorns.htm
Hi Andrew
I don’t recall the figure of 30 dB (its been some years now) but the comparison should be of maximum acoustic power.
Sensitivity is a different issue.
In the Lab sub, the drivers raw sensitivity was about 88dB 1W 1M, a group of 6 labs has a sensitivity of about 108-110dB 1W1M.
If one is interested in “greater than 1Watt” then one finds the Lab subs run out of excursion at 30Hz at somewhere around 1200-1600Watts per box.
If you model a box with –3 at about 32Hz and model popular 18 inch drivers and also keep them within Xmax and make the ports large enough to work at high power, It actually does take a large number of 18’s in vented boxes to make that much sound.
At the shoot outs so far, the Lab has been the most powerful and lowest distortion of concert style subs tested.
Fwiw, the lab sub is not a product but rather a free DIY project for pro-sound.
Its size and cutoff were specified by the group for use in groups in large scale concert sound, it is not for everyone by any means.
Heck, they didn’t ask for a small subwoofer.
Tom Danley
Danley Sound Labs
I don’t recall the figure of 30 dB (its been some years now) but the comparison should be of maximum acoustic power.
Sensitivity is a different issue.
In the Lab sub, the drivers raw sensitivity was about 88dB 1W 1M, a group of 6 labs has a sensitivity of about 108-110dB 1W1M.
If one is interested in “greater than 1Watt” then one finds the Lab subs run out of excursion at 30Hz at somewhere around 1200-1600Watts per box.
If you model a box with –3 at about 32Hz and model popular 18 inch drivers and also keep them within Xmax and make the ports large enough to work at high power, It actually does take a large number of 18’s in vented boxes to make that much sound.
At the shoot outs so far, the Lab has been the most powerful and lowest distortion of concert style subs tested.
Fwiw, the lab sub is not a product but rather a free DIY project for pro-sound.
Its size and cutoff were specified by the group for use in groups in large scale concert sound, it is not for everyone by any means.
Heck, they didn’t ask for a small subwoofer.
Tom Danley
Danley Sound Labs
I'd have to disagree with Mike.e about the labs being expensive compared to the 1850 horn. The single 18 for the 1850 is £280, versus £255 for a pair of the lab12 drivers for the labhorns.
In the US the lab12 drivers are a steal at about $140 each.
The rest is just plywood and efffort. The labs are definitely harder to build than the 1850's though.
Cheers,
Rob
Edit: should have asked why the original poster wanted to build 2 horns of each type ,eg: 2 of 21" + 2 of 15" and not just four of 1 type of cabinet ?
edit edit :
Thanks Tom for designing the labs - am looking forwards to hearing my pair in the next couple weeks
In the US the lab12 drivers are a steal at about $140 each.
The rest is just plywood and efffort. The labs are definitely harder to build than the 1850's though.
Cheers,
Rob
Edit: should have asked why the original poster wanted to build 2 horns of each type ,eg: 2 of 21" + 2 of 15" and not just four of 1 type of cabinet ?
edit edit :
Thanks Tom for designing the labs - am looking forwards to hearing my pair in the next couple weeks
Hi all,
thanks to Tom for the reply and for all that design effort and subsequently in the literature supporting the Labhorn.
Tom D. said ten times as much power to drive the vented cabinets to similar volume. That to me means +10db in power terms. The +30db is a misquote that came from nowhere.
thanks to Tom for the reply and for all that design effort and subsequently in the literature supporting the Labhorn.
Tom D. said ten times as much power to drive the vented cabinets to similar volume. That to me means +10db in power terms. The +30db is a misquote that came from nowhere.
Cheers Mike,
Had a look- am assuming you're talking about the 'snailshell' horns on the site?
I've been looking around for plans for a kick type horn (80 - 250ish) I was ~assuming~ they'd be a straight horn though - Speakerplans was going that way I believe, then just stopped ? - Got to say I didn't follow it too closely though.. (I'm on a bad dial up connection)
Have to admit I've tried using hornresponse a few times now and its a bit confusing
Trouble with these horn thingies is you tend to run out of space fast across your front wall......
Rob.
Had a look- am assuming you're talking about the 'snailshell' horns on the site?
I've been looking around for plans for a kick type horn (80 - 250ish) I was ~assuming~ they'd be a straight horn though - Speakerplans was going that way I believe, then just stopped ? - Got to say I didn't follow it too closely though.. (I'm on a bad dial up connection)
Have to admit I've tried using hornresponse a few times now and its a bit confusing
Trouble with these horn thingies is you tend to run out of space fast across your front wall......
Rob.
RobWells said:Cheers Mike,
Had a look- am assuming you're talking about the 'snailshell' horns on the site?
I've been looking around for plans for a kick type horn (80 - 250ish) I was ~assuming~ they'd be a straight horn though - Speakerplans was going that way I believe, then just stopped ? - Got to say I didn't follow it too closely though.. (I'm on a bad dial up connection)
Have to admit I've tried using hornresponse a few times now and its a bit confusing
Trouble with these horn thingies is you tend to run out of space fast across your front wall......
Rob.
Thats right,people have busy lives and cant do unpaid projects always.
I was on bad dial up,currently I just use the polytech connection on the weekends. The HD15 in atleast a pair,seems to do the range your wanting. Not sure how nice the response is at 250hz but people seem to use it up that high. Why re invent the wheel?its either gona be a straight horn or some long,serpentine well folded horn-which i dont know how well it will do 250hz without sounding honky.
Hi Mike,
tbh I'm just looking around atm as to what is available, and how large the enclosures are. I actually don't have enough space in my room to go all horn. Will stick to my hi-eff pro 15's for midbass, with my pro 10's and cd/horns for the mid/tweets.
I was looking at the edgar horns as about the 'usual' size of an 80Hz bin. It's a fairly short length with a big cone I believe. Looks a bit like the altec bins aswell. I think the horn length is a lot shorter than your 40 Hz one. I'd be looking at these before the HD15's, but at the moment it's all just prep work in case I get a bigger room someday. Maybe by then I'll actually have put the time in with horn response.
I'm not expecting people to design it for me, but reading of other projects gives me an idea of what is / isn't possible..(we all have to start somewhere!)
Cheers,
Rob
tbh I'm just looking around atm as to what is available, and how large the enclosures are. I actually don't have enough space in my room to go all horn. Will stick to my hi-eff pro 15's for midbass, with my pro 10's and cd/horns for the mid/tweets.
I was looking at the edgar horns as about the 'usual' size of an 80Hz bin. It's a fairly short length with a big cone I believe. Looks a bit like the altec bins aswell. I think the horn length is a lot shorter than your 40 Hz one. I'd be looking at these before the HD15's, but at the moment it's all just prep work in case I get a bigger room someday. Maybe by then I'll actually have put the time in with horn response.
I'm not expecting people to design it for me, but reading of other projects gives me an idea of what is / isn't possible..(we all have to start somewhere!)
Cheers,
Rob
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