Rob ... I wish!!!!
This is the project I'd love to build, but I haven't yet moved into the place that would allow such a beast. It's not likely to happen until next year
I have since discovered the benefits of back to back driver mounting to reduce vibration of a box. Hence when I do build it, I will use back to back mounting like in the Lab horn because it makes a huge difference in box vibration. This is really needed because a thick and overdesigned box (like I'd do for a small sub) is just going to be too heavy. I think the top box will have to be installed by chocking it up on bricks, then using car jacks to get it up slowly but surely.
My audio hobby is currently taking a back seat to real estate, with which I am to eventually finance a big home theatre room with this bass horn and some high output open baffle mains.
Any news with your system Rob?
This is the project I'd love to build, but I haven't yet moved into the place that would allow such a beast. It's not likely to happen until next year
I have since discovered the benefits of back to back driver mounting to reduce vibration of a box. Hence when I do build it, I will use back to back mounting like in the Lab horn because it makes a huge difference in box vibration. This is really needed because a thick and overdesigned box (like I'd do for a small sub) is just going to be too heavy. I think the top box will have to be installed by chocking it up on bricks, then using car jacks to get it up slowly but surely.
My audio hobby is currently taking a back seat to real estate, with which I am to eventually finance a big home theatre room with this bass horn and some high output open baffle mains.
Any news with your system Rob?
Hi Paul,
Yep you're going to need a big room for those beasts
I ripped my room out in May and am just about getting it all back together - been playing with midbass horns to get an all horn 4-way. At the moment its jbl 2020H 12" in an 80cm long, 1/4 size mouth. Not bad at all, and surprising small. I'm using the Edgar midrange horns from his old magazine articles (with the JBL LE-5 drive) with a JBL 2402 bullet for tweeters.
I'm still undecided about the sub 25Hz stuff. I can either build another 2 labhorns and do serious EQ or go back to my 4 tempests. TBH the rooms getting as full as it can be now, so I may stick with 'just' the 2 labhorns for now. I don't seem to be missing the lows, but haven't put a dvd through the system since May.
Never ends, does it?
Cheers,
Rob.
Yep you're going to need a big room for those beasts
I ripped my room out in May and am just about getting it all back together - been playing with midbass horns to get an all horn 4-way. At the moment its jbl 2020H 12" in an 80cm long, 1/4 size mouth. Not bad at all, and surprising small. I'm using the Edgar midrange horns from his old magazine articles (with the JBL LE-5 drive) with a JBL 2402 bullet for tweeters.
I'm still undecided about the sub 25Hz stuff. I can either build another 2 labhorns and do serious EQ or go back to my 4 tempests. TBH the rooms getting as full as it can be now, so I may stick with 'just' the 2 labhorns for now. I don't seem to be missing the lows, but haven't put a dvd through the system since May.
Never ends, does it?
Cheers,
Rob.
two lab horns may not be enough...
In the sub dept. you'll want more mouth area than two labs afford. I've replaced my huge bass horn with four 18", hi X-max drivers -- 2 per ported, 15 cu.ft enclosure. I've eq'd the heck out of them and coupled up a Behringer 2400 watt europower amp. Now, the air around me fans my skin during strong bass passages -- a most extraordinary experience!
Perhaps you can cut a hole through your outer wall and build a doghouse that will accommodate 4 lab horns?
Sounds like a wonderful system!
John
In the sub dept. you'll want more mouth area than two labs afford. I've replaced my huge bass horn with four 18", hi X-max drivers -- 2 per ported, 15 cu.ft enclosure. I've eq'd the heck out of them and coupled up a Behringer 2400 watt europower amp. Now, the air around me fans my skin during strong bass passages -- a most extraordinary experience!
Perhaps you can cut a hole through your outer wall and build a doghouse that will accommodate 4 lab horns?
Sounds like a wonderful system!
John
Hi John,
The labs are corner loaded, and in theory work as well as at least 4 in half space. I can guarantee they give more than enough output within their loaded range (above 30Hz). I have used them with 3 sealed tempests (15"). The tempests tied in well with room gain - they are flat 15 - 30Hz with no eq. Only about -5dB at 10Hz.
Right now they are doing me just fine. It's when I get my projector back in the room and start watching films that I may want more sub 30Hz output. Still have 4 tempest drivers, and have the wood cut for another 2 labhorns. Also have the wood cut for the 4 tempests aswell.
Tom Danley reckoned 4 labs would work:
http://srforums.prosoundweb.com/index.php/t/15284/0/
The doghouse idea is pefect, and if I didn't rent my home I think I'd have done it already
Cheers,
Rob.
The labs are corner loaded, and in theory work as well as at least 4 in half space. I can guarantee they give more than enough output within their loaded range (above 30Hz). I have used them with 3 sealed tempests (15"). The tempests tied in well with room gain - they are flat 15 - 30Hz with no eq. Only about -5dB at 10Hz.
Right now they are doing me just fine. It's when I get my projector back in the room and start watching films that I may want more sub 30Hz output. Still have 4 tempest drivers, and have the wood cut for another 2 labhorns. Also have the wood cut for the 4 tempests aswell.
Tom Danley reckoned 4 labs would work:
http://srforums.prosoundweb.com/index.php/t/15284/0/
The doghouse idea is pefect, and if I didn't rent my home I think I'd have done it already
Cheers,
Rob.
Hi,
1.5 labhorns work when corner loaded.
3 for two plane loading and 6 for floor or wall only loading.
Any more for each load condition does not lower the bass roll off point.
The flare rate becomes the limiting factor once you have adequate mouth area.
A longer labhorn (allowing a slower flare rate) would be required for a lower "horn loaded" frequency.
An advantage of using more Labhorns is the gain in cone area allowing EQ to be used to electronically extend the low end. But ends up copying the Tempests.
1.5 labhorns work when corner loaded.
3 for two plane loading and 6 for floor or wall only loading.
Any more for each load condition does not lower the bass roll off point.
The flare rate becomes the limiting factor once you have adequate mouth area.
A longer labhorn (allowing a slower flare rate) would be required for a lower "horn loaded" frequency.
An advantage of using more Labhorns is the gain in cone area allowing EQ to be used to electronically extend the low end. But ends up copying the Tempests.
Hi Andrew,
Don't forget that the corner placement recommended by Tom D on PSW will extend the mouth beyond the cab. Unforunately it doesn't really help me as my ceiling gets higher in the middle, ruining the idea. My ceiling is 8' at either end, but 4' into the room it slopes up to approx 10'. Kind of like this from the side:
__/^^^^^^^^\__ .
It would need to be a constant 8' to benefit properly.
Cheers,
Rob.
Don't forget that the corner placement recommended by Tom D on PSW will extend the mouth beyond the cab. Unforunately it doesn't really help me as my ceiling gets higher in the middle, ruining the idea. My ceiling is 8' at either end, but 4' into the room it slopes up to approx 10'. Kind of like this from the side:
__/^^^^^^^^\__ .
It would need to be a constant 8' to benefit properly.
Cheers,
Rob.
Attachments
Hi Rob,
Corner loading is great, but you've got to keep in mind that sheet-rock is much weaker than plywood and therefore offers less control of the bass wave. The outer wall sheathing helps, but is only 1/2", generally. what would be terrific is to mount cement backer board onto the walls -- then you have greater support and a stronger impact on the wave.
All in all, I enjoyed my 30hz bass horn. If it weren't so darn big, it would still be in my system. Alas, it had to go in order to make room for my 18" subs. As an aside, I prefer the tonal qualities of my reflex cabinets over those of the horn.
Whatever your poison, here's to great listening.
John
Corner loading is great, but you've got to keep in mind that sheet-rock is much weaker than plywood and therefore offers less control of the bass wave. The outer wall sheathing helps, but is only 1/2", generally. what would be terrific is to mount cement backer board onto the walls -- then you have greater support and a stronger impact on the wave.
All in all, I enjoyed my 30hz bass horn. If it weren't so darn big, it would still be in my system. Alas, it had to go in order to make room for my 18" subs. As an aside, I prefer the tonal qualities of my reflex cabinets over those of the horn.
Whatever your poison, here's to great listening.
John
Re: Hi Rob,
John that is an excellent point that most people would not even consider. In a perfect world I would build my own listening room out of brick / concrete and not have that problem. As it is I'll just have to live with the compromises of my rooms construction...
*Rob starts thinking of false corners built from braced mdf / ply sandwiches*
carpenter said:Corner loading is great, but you've got to keep in mind that sheet-rock is much weaker than plywood and therefore offers less control of the bass wave. The outer wall sheathing helps, but is only 1/2", generally. what would be terrific is to mount cement backer board onto the walls -- then you have greater support and a stronger impact on the wave.
John
John that is an excellent point that most people would not even consider. In a perfect world I would build my own listening room out of brick / concrete and not have that problem. As it is I'll just have to live with the compromises of my rooms construction...
*Rob starts thinking of false corners built from braced mdf / ply sandwiches*
Sandwich the concrete board between 7/16" OSB (waffer-board), edge with 1 x 2, and paint with a faux finish...
Join the panels to create a corner, add casters and viola!If the horn doesn't sound good you can always sell your work to a photographer as a backdrop.
John likes the way Rob thinks...
If your room was as solid as bricks/concrete, then you would have a problem! A different problem - serious modes as I'm sure you are aware. Earl Geddes recommends in his home theatre book to use two layers of "sheetrock" (plasterboard in Aus) glued with liquid nails and attached to horizontal metal furring channels, staggered studs and the same on the other side of the wall - this is both for bass damping and attenuation. Reinforcing where the mouth transitions around the corner does make sense to me.
I do wonder how much the room walls vibrating messes up the sound. Go outside the room and the sound is ugly.
Rob, what have you built your labs out of? (thickness and material)
How do they perform as far as vibtation? Are they solid enough for hifi use?
John, what drivers did you use?
I do wonder how much the room walls vibrating messes up the sound. Go outside the room and the sound is ugly.
Rob, what have you built your labs out of? (thickness and material)
How do they perform as far as vibtation? Are they solid enough for hifi use?
John, what drivers did you use?
Hi Paul,
I built my labhorns from 18mm mdf. Reason is mainly financial - I cut enough for 4 labhorns. That takes about 10 8' x 4' sheets iirc. mdf costs £130 UK. Ply costs £400 UK. Reading up on materials it seemed not to matter too much at sub frequencies. As to cabinet vibration, it doesn't seem to be a problem. Maybe when I build my next 2 I'll do some waterfall plots to see if there's anything causing trouble.
If I'd had the cash I would have built from ply just for peace of mind though.
As to the hifi usage, to my ears they sound cleaner than any 'normal' subwoofer I've heard. The servo type sealed subs have a similar signature to them, but are spl limited. I guess the only way you'll find out is to build some though. Why don't you knock up a single horn sub for one of your drivers and whack it in a corner for a listen ? An 's' type fold would be quick and easy, and only set you back a few bucks for a couple of sheets of mdf.
Cheers,
Rob.
I built my labhorns from 18mm mdf. Reason is mainly financial - I cut enough for 4 labhorns. That takes about 10 8' x 4' sheets iirc. mdf costs £130 UK. Ply costs £400 UK. Reading up on materials it seemed not to matter too much at sub frequencies. As to cabinet vibration, it doesn't seem to be a problem. Maybe when I build my next 2 I'll do some waterfall plots to see if there's anything causing trouble.
If I'd had the cash I would have built from ply just for peace of mind though.
As to the hifi usage, to my ears they sound cleaner than any 'normal' subwoofer I've heard. The servo type sealed subs have a similar signature to them, but are spl limited. I guess the only way you'll find out is to build some though. Why don't you knock up a single horn sub for one of your drivers and whack it in a corner for a listen ? An 's' type fold would be quick and easy, and only set you back a few bucks for a couple of sheets of mdf.
Cheers,
Rob.
I always felt the sensation that the 30hz horn fell short in the deep bass region. The four 18s that I'm now using always seem to be ready to rumble.
Paul. I'm only suggesting the use of solid wall construction where the horn mouth meets two walls. There's no way in hell you or anyone else is going to convince me that flimsy wall construction is adequate for a bass horn and associated response! Use a bass trap/mat to deaden reflections. Two layers of sheetrock on metal Z channel is primarily for sound deadening in adjoining rooms. At least, that's how I've always seen in used in construction.
If you have the space for a straight bass horn, then you'll get superior reproduction, folding the horn kills the minute details. It's like listening to someone speak in the next room. The details get muddied and enunciation is dulled. My sub woofers don't have the immediacy of the 30hz horn, but they do have more detail. Quite frankly, my current system reproduces drums better than anything from my past.
When I build my shop next summer, I'll have a "showroom" on the second floor. At that point in time I plan to fabricate a straight, 20 foot long, full size bass horn -- we're talking a mouth that's 12 feet by 20 feet. It will be behind the listener in order to allow for time alignment.
John
Paul. I'm only suggesting the use of solid wall construction where the horn mouth meets two walls. There's no way in hell you or anyone else is going to convince me that flimsy wall construction is adequate for a bass horn and associated response! Use a bass trap/mat to deaden reflections. Two layers of sheetrock on metal Z channel is primarily for sound deadening in adjoining rooms. At least, that's how I've always seen in used in construction.
If you have the space for a straight bass horn, then you'll get superior reproduction, folding the horn kills the minute details. It's like listening to someone speak in the next room. The details get muddied and enunciation is dulled. My sub woofers don't have the immediacy of the 30hz horn, but they do have more detail. Quite frankly, my current system reproduces drums better than anything from my past.
When I build my shop next summer, I'll have a "showroom" on the second floor. At that point in time I plan to fabricate a straight, 20 foot long, full size bass horn -- we're talking a mouth that's 12 feet by 20 feet. It will be behind the listener in order to allow for time alignment.
John
Yes, the 30hz horn began life as a bass horn, not a sub. My first crossover point was 190hz, where the lower-mid horn took over. A tremendous amount of detail is delivered in the 80hz to 450hz range, which is where my new bass reflex/dual JBL 2123s are operating. The goose-neck of the bass horn created anomalies and wasn't capable of delivering clean, distortion free mid-bass.
The sub drivers I'm currently using overlap the mid-bass spectrum just enough to offer a pleasant boost in the lower mid-bass spectrum. I've eq'd most of the mid-bass from the subs, but a little gets through. The results create a very lifelike sound. The bass horn didn't have these slight, delicate overtones that the 18s do.
When I compare the bass horn with the 18s, I find that the trade-offs favor the 18s; I can't help but believe that a straight horn, bass included, is only way to go for highest fidelity.
I think that everyone has to go through the process, lord knows I did. Build that big-*** horn and live with it for half a decade and then, when the bias wears off, make an informed decision as to which system is best for your ears.
John
The sub drivers I'm currently using overlap the mid-bass spectrum just enough to offer a pleasant boost in the lower mid-bass spectrum. I've eq'd most of the mid-bass from the subs, but a little gets through. The results create a very lifelike sound. The bass horn didn't have these slight, delicate overtones that the 18s do.
When I compare the bass horn with the 18s, I find that the trade-offs favor the 18s; I can't help but believe that a straight horn, bass included, is only way to go for highest fidelity.
I think that everyone has to go through the process, lord knows I did. Build that big-*** horn and live with it for half a decade and then, when the bias wears off, make an informed decision as to which system is best for your ears.
John
Greets!
Been there, done that! It broke my heart to have to sell my decades old 80 Hz dual 515B FLHs some years ago, until I hooked up my dual 515B corner loaded 16 Hz 'subs' to the 500 Hz horns that is. The extra efficiency isn't missed enough to matter, and with no confining throat pressure to damp low level detail..........
GM
Been there, done that!
It broke my heart to have to sell my decades old 80 Hz dual 515B FLHs some years ago, until I hooked up my dual 515B corner loaded 16 Hz 'subs' to the 500 Hz horns that is. The extra efficiency isn't missed enough to matter, and with no confining throat pressure to damp low level detail.......... GM
Hi GM,
It's funny as I'm coming from the other direction - I had the pro 15" driver per side with a pro 10" mid / 1KHz CD horn above. I'm finding a straight midbass horn is sounding better to me. Of course I haven't had the chance to get my hands on some 515B's though.....(yet!)
Are you talking about the 511B horn btw ? I have a pair of them but haven't sourced a pair of drivers for them yet.
For me it's been difficult to explore horns. The popular drivers are pretty rare in the UK, and I don't know anybody who has any horns for me to demo. If I want to hear them I have to buy them / build them myself.
Still, I'm enjoying the journey so far so its all good.
Cheers,
Rob.
It's funny as I'm coming from the other direction - I had the pro 15" driver per side with a pro 10" mid / 1KHz CD horn above. I'm finding a straight midbass horn is sounding better to me. Of course I haven't had the chance to get my hands on some 515B's though.....(yet!)
Are you talking about the 511B horn btw ? I have a pair of them but haven't sourced a pair of drivers for them yet.
For me it's been difficult to explore horns. The popular drivers are pretty rare in the UK, and I don't know anybody who has any horns for me to demo. If I want to hear them I have to buy them / build them myself.
Still, I'm enjoying the journey so far so its all good.
Cheers,
Rob.
Greets!
Yeah, we are, my first full range speaker was all horn corner loaded, but you really need to audition a pair/channel to understand where I'm coming from now, or not, depending on what sounds most realistic to you. I haven't auditioned any similar TADs, GOTOs, etc., but to date there's been no equal JBL (the company since he designed the 515 AFAIK), Eminence, B&C, etc., though I've hardly auditioned all of their offerings, especially recent ones.
Obviously, the driver, horn alignment, and XO has much to do with whether the detail gets lost (assuming it was ever there) and my 210/211 midbass horns were intrinically flawed by design. Still, I had never run 515Bs up high except in these and 825 horns, which sounded so detailed compared to other fare, including the much praised 416 series, so was rather surprised how much they opened up in an EBS alignment without the usual 'tail wagging the dog' distortion when a point source driver is 'forced' to cover > five octaves. Similar in magnitude of the difference between a sealed cab and dipole.
That said, I've built midbass horns that don't lose the detail, but they were designed to only cover a narrow BW to couple up with a 300 Hz compression loaded horn where the detail is becoming audible, so I have no doubt that if I'd done this with the 210s we probably wouldn't be having this conversation now.
Yeah, my current horns are mildly damped 511s. They have their 'charms', though accurate they're not, no matter how much you grind/cut/damp them, but then they weren't designed to be.
Understood, what cone and compression drivers are available locally or within budget?
GM
Yeah, we are, my first full range speaker was all horn corner loaded, but you really need to audition a pair/channel to understand where I'm coming from now, or not, depending on what sounds most realistic to you. I haven't auditioned any similar TADs, GOTOs, etc., but to date there's been no equal JBL (the company since he designed the 515 AFAIK), Eminence, B&C, etc., though I've hardly auditioned all of their offerings, especially recent ones.
Obviously, the driver, horn alignment, and XO has much to do with whether the detail gets lost (assuming it was ever there) and my 210/211 midbass horns were intrinically flawed by design. Still, I had never run 515Bs up high except in these and 825 horns, which sounded so detailed compared to other fare, including the much praised 416 series, so was rather surprised how much they opened up in an EBS alignment without the usual 'tail wagging the dog' distortion when a point source driver is 'forced' to cover > five octaves. Similar in magnitude of the difference between a sealed cab and dipole.
That said, I've built midbass horns that don't lose the detail, but they were designed to only cover a narrow BW to couple up with a 300 Hz compression loaded horn where the detail is becoming audible, so I have no doubt that if I'd done this with the 210s we probably wouldn't be having this conversation now.
Yeah, my current horns are mildly damped 511s. They have their 'charms', though accurate they're not, no matter how much you grind/cut/damp them, but then they weren't designed to be.
Understood, what cone and compression drivers are available locally or within budget?
GM
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