Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Artichoke Horn
Artichoke Horn
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th October 2016, 03:45 AM   #11
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Artichoke Horn
40 foot or 20 foot? You could get a nice long horn in a 20 footer.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 28th October 2016, 03:55 AM   #12
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Quote:
Originally Posted by Pano View Post
FWIW, the famous W.E. 15A horn is 15 feet long, but curled up. The mouth is about 1/2 that size I think.
I've seen photos of that - but I didn't realise it was so large. I'm glad you mentioned it:

a) simply because it is a beautifully crafted object, IMO, and a good bit of design inspiration.
b) I like how the modules are fitted together. I might steal their idea, one day, e.g. for swappable horn throats.
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 28th October 2016, 04:08 AM   #13
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Quote:
Originally Posted by Pano View Post
40 foot or 20 foot? You could get a nice long horn in a 20 footer.
Yep. And for some people, that'd make sense.

Personally, if I were to do this, I'd go for a 40' container, because they only cost slightly more than a 20' and I'd get a lot of other use from the extra volume.
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 28th October 2016, 05:54 AM   #14
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by hollowboy View Post
1)I haven't heard gargle in years, since I moved up from bookshelf speakers. But yes, I was thinking it would be one of two options-
Like the original: straight throat, large bandwidth, maybe 30-800Hz, ~110dB peaks
As a sub: two or four drivers, J-shape throat, maybe 20-100Hz, ~120dB peaks
2) Interesting. You mean a slot throat (6' wide, 15' high)?
Your axe-head shaped 'plug' looks like a do-able project (without getting fancy with CNC or casting). Would there be any negative to continuing that division for the first metre (or more) of the throat - like a multicell? I've long been curious about applying the multicell concept to a cone driver.
3)If I ever made a project like this, the shipping container would be the workshop
The container would be primarily a tool shed and an anchor point for shade cloth (it gets pretty hot here). I'd cut a door into one side, so I could continue using it for storage; the horn would only use the front 1/3 of a full-sized shipping container.
1) Using a moderate excursion (around 6MM Xmax) single woofer on a huge straight horn covering 30 to 800 Hz could effortlessly (cleanly) do well in excess of 125 dB at one meter. With four drivers in the 20-100 Hz range you could jack that up by an easy 6 dB, and you would not get "dirty" complaints with 140 dB peaks.
2) Yes, you can see how it was made from the pictures, just used a table saw and router. There is no reason to continue the phase plug past the wavelength it is designed to work to. Multicell horns are not a design I would choose for any reason other than the nostalgic "sound" they evoke, which ain't bad, but is a far cry from providing the even polar response I prefer.
3) I built dozens of cabinets in a shop/sound equipment 18' utility trailer (side and rear doors, 4" rear equipment partition), had some really serious wrecks with it due to not reloading to place the primary mass in the center of the trailer before taking off to do gigs. Be careful if you use a full-sized shipping container to move gear if the load is not centered or evenly distributed, or you might end up like I did, having to steer a runaway trailer away from traffic after the class III hitch sheared off when the trailer went into a death shimmy and threw the rear of the tow van into a retaining wall, breaking it loose across three lanes of traffic.

It was scary, and made me late for the load in, had to get the trailer towed back to the motel, replace the bent wheel on the van, and then load the equipment from the trailer in to it.

Then the load in had a flight of stairs, and no stage hands...

I got to get out of my memories of the "good old days.."

Art
  Reply With Quote
Old 28th October 2016, 08:35 AM   #15
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Quote:
Originally Posted by weltersys View Post
1) Using a moderate excursion (around 6MM Xmax) single woofer on a huge straight horn covering 30 to 800 Hz could effortlessly (cleanly) do well in excess of 125 dB at one meter. With four drivers in the 20-100 Hz range you could jack that up by an easy 6 dB, and you would not get "dirty" complaints with 140 dB peaks.
I tweaked my Artichoke sim to check that: yep, reducing the box to 50 litres would give 125dB with 6mm excursion (the penalty being a 2dB dip at 40Hz).

I'm way more conservative than you / listen relatively quietly. The one time I had a big (fixed) system, where I could play as loud as I wanted, I still used pretty low power. When I really cranked it (by my standards), the meter indicated I was only using the first couple of watts, of a 70 watt amp.

The LF portion was cheapo 15" drivers, but a quad, and corner loaded, so the system should have been ~100dB per watt.

Based on this, I think I'd only ever use a watt or two if running a big horn rig (107 dB/watt). So a really tiny amp would do it: battery power.

Quote:
Originally Posted by weltersys View Post
There is no reason to continue the phase plug past the wavelength it is designed to work to.
OK, thanks.

Good (scary!) trailer story - but not for me: if I went down this route, it would be a fixed installation.

That is: if I get a container, it'd be mainly as a shed, for storage & general utility. The horn would be a bonus that I'd only need to buy the concrete for - I have plenty of scrap wood, and various suitable drivers just sitting there.
__________________
This edit signature thingy is seriously hard to find

Last edited by hollowboy; 28th October 2016 at 08:48 AM.
  Reply With Quote
Old 28th October 2016, 01:56 PM   #16
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by hollowboy View Post
1)I tweaked my Artichoke sim to check that: yep, reducing the box to 50 litres would give 125dB with 6mm excursion (the penalty being a 2dB dip at 40Hz).
2)I'm way more conservative than you / listen relatively quietly.
Based on this, I think I'd only ever use a watt or two if running a big horn rig (107 dB/watt). So a really tiny amp would do it: battery power.
3)Good (scary!) trailer story - but not for me: if I went down this route, it would be a fixed installation.
Hollowboy,

1) I was just going from my memories of big horn measurements, glad they were correct.
2) I never mix or listen to music at over OSHA prescribed levels even at concerts. At home I seldom exceed 80 dBA, though I don't mind 30-40 Hz at 110 dB now and then.
Even using relatively inefficient speakers, a 15 watt solar panel with a reasonably sized battery would easily power a class D amp for my listening levels even in the shop, keeping up with power tools.
3) What is really scary evidence of my failure to learn from mistakes is that was the second "trailer wagging the van" event. The first time the trailer whipped the van's rear wheel into the freeway curb hard enough to break the wheel off the axle, and the lateral force bent two of the four trailer wheels on the opposite side enough that one tire blew out from rubbing before we made it back to the storage pen after dropping off some speakers loaned to a record store friend of a friend. Hmm, that friend also convinced me to haul a marginally packed over-loaded flat-bed trailer across country too..

Fortunately we were able to get back to tow the three-wheeled van back home just before it was going to be hauled to an impound lot.

At any rate, good to hear your intentions for the container would be static.

Back when I was selling "sound by the pound", and USA trailers had grown bigger and bigger, bought a "small" 40 foot "reefer" (insulated for refrigeration) trailer for just $1500. The 286 square feet of interior space paid for itself in reduced warehouse rental space needed in less than a year, and being truck height, made transferring gear in and out a breeze. I sold the reefer with the rest of my company's gear after using it for 7 more years, it still towed as good as new.

Art
  Reply With Quote
Old 25th November 2016, 10:07 PM   #17
j.michael droke is offline j.michael droke  United States
diyAudio Member
 
Join Date: Jan 2009
Artichoke Horn
Default Horn:throat & phase plug

Quote:
Originally Posted by weltersys View Post
... 2) If the horn is to be used up to 800 Hz or so, the throat should be narrowed to around 6 inches wide for better dispersion and phase response, or better yet, use a phase plug as shown in the photos below. ...... This type of phase plug is similar to the ones Dave Gunness designed for the 10" mids in the EV MT systems from the mid 1980s.... Art
Hi there Art: Many thanks for the information on horn throat configuration and/or design of phase plug per photographs. Always wondered why the A7 I constructed from Altec plans, in 1963, had a throat narrowed from 15" driver to 8-inch wide x 16"long slot. ...regards Michael

Last edited by j.michael droke; 25th November 2016 at 10:08 PM. Reason: corrected "Art"
  Reply With Quote
Old 26th November 2016, 04:47 AM   #18
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by j.michael droke View Post
Hi there Art: Many thanks for the information on horn throat configuration and/or design of phase plug per photographs. Always wondered why the A7 I constructed from Altec plans, in 1963, had a throat narrowed from 15" driver to 8-inch wide x 16"long slot. ...regards Michael
Michael,

1963 build, jeez, you must be a really old fart, I hadn't even heard one before 1969 or so .

Glad to be "At" attention, and to have explained your "wonders"

Cheers and Happy Black Friday Holidays!

"At"
  Reply With Quote
Old 13th December 2016, 06:59 AM   #19
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
I'm creeping forward on my shipping container idea. I'm still at the stage of clearing the obstacles, figurative and literal:

-I need a building permit ($500 and paperwork)
-Physical access (I'm removing a few trees so a big truck can get in)

I'd like advice on choosing between two layouts:

Layout 1) is basically the horn in post 1, but split for stereo.

Or imagine the attached white picture, crammed into a 8' wide space (no gap between horns).
I would similarly use 4 drivers per side to keep the horn short(ish)
LF horns would be 4m long (flat to 30Hz)
I'd try this as a 3-way, with 4" / 1" horns for HF, permanently nested inside the LF horns

Pros: simple, I like the look, maximal use of the big horn.
Cons: not sure if it will work. Small sweet spot.

Layout 2 ) is basically the post 1 (mono) horn, plus separate mains for stereo. I'd probably use a pair of 18" for the LF horn.

In this case, I'd mount the mains on the inside of the shipping container doors (with castors on the doors, to cope with the additional weight), to make setup as simple as swinging the doors open.

Pros: easier to get right, better use of drivers I already have
Cons: seems like a waste of the big horn.
lower crossovers = bigger c-to-c spacing on mid-HF cross & requiring a 2" tweeter = poorer HF (or need to go 4-way).

So it seems like 1) would be a better nearfield system, 2) would be better further out, with a bigger sweet spot.

Is there something else I haven't thought of, that would rule out either option?

Electronics:

I'd love to keep it simple and use what I already know.

miniDSP as active crossover
Dayton Audio DTA-1 for HF
Trends Audio amp for LF

Can I simply run a mini DSP from a powerbank (a battery with a USB interface, intended for recharging smartphones)?

The DTA-1 is built to run off AA batteries. It sounds thin to me, as a full range amp, but should be OK as a HF amp.

The Trends Audio is a nice amp, mine runs very cool even compared to other amps of the type, and lots of people use it with battery power. Their website says: "The 12V lead-acid rechargeable battery should be a good alternative (battery provides purer DC than electric network)."

I'd use passive components for the mid-high cross.

Have I missed anything obvious with this? I'll transpose this part to an amp forum if that'd be better.

Background / limitations:
  • I'd like to be able to seal it up easily between visits (the doors must remain functional, this sets the horn mouth to a maximum of 244x259cm - 8' wide and 8'6" tall).
  • I will add a secondary door at the other end, so I can use the rest of the container for storage.
  • I want to run it off batteries.
  • My electronics skills are basic. I can solder and use a multimeter, but I know little about power supply.
  • I have a lot of drivers and parts already.
  • I'm in no hurry.
  • Any critical listening will be nearfield and 1 watt will be plenty.
  • I'm not a components snob; a mini DSP sounds fine to me.
  • I'm happy to do all the construction.
  • Weight is no issue - I will build with cheap ply then add a ton or three of concrete.
Attached Images
File Type: jpg White dual quad.jpg (28.8 KB, 257 views)
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 13th December 2016, 07:22 AM   #20
AllenB is online now AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Quote:
Originally Posted by hollowboy View Post
Weight is no issue - I will build with cheap ply then add a ton or three of concrete.
The container on its own weighs a couple of tonnes, filled with concrete it's around 80t. They are rated for 30t.
  Reply With Quote

Reply


Artichoke HornHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Horn experts - Please help to determine optimal throat size for low-mid horn pk Multi-Way 9 19th August 2012 07:29 PM
Folded horn - volume between subwoofer cone ane th start of the horn benpalmer Subwoofers 8 9th April 2012 02:10 PM
Ron's Austin II, old T-Horn, Lab12 Tapped horn, CNC Photo Background layertone Full Range 2 23rd December 2009 01:51 AM
looking for 6.5inch woofers suitable for a 30 - 35Hz horn... and a small horn too :P SkinnyBoy Multi-Way 24 13th February 2004 06:06 AM


New To Site? Need Help?

All times are GMT. The time now is 05:56 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki