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Author Topic: Direct versus Folded Horn Sub enclosures  (Read 47852 times)

Tom Young

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Re: Direct versus Folded Horn Sub enclosures
« Reply #20 on: December 15, 2011, 05:24:06 PM »

Okay just remember seeing a band with folded horn and every time I went to walk to the side of the subs you could hear a huge difference in volume loss on the kick and bass but once you got back in front they would hit you hard. Keep in mind this was many moons ago like back in the 90's I can't even remember hat subs they had just remember they were folded horn design and huge and look like you needed a forklift to move them around.
All thought the band was kick ass hair metal type.

My experience lies completely with commercially made (or copied) bass horns. None of these was big enough to need a forklift. A large enough folded bass horn could provide some off axis attenuation.

Another possible contributor is that if you walked to the outside of split L&R bass horns there would be less combined LF energy, IOW you are walking out of "power alley".

HTH
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Tom Young
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Tom Young

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Re: Direct versus Folded Horn Sub enclosures
« Reply #21 on: December 15, 2011, 05:27:57 PM »

My experience with horn subs, has never been great, the move to direct radiating subs has (IMHO) been a blessing for live sound.  I was never a lover of bandpass boxes either, again far too coloured and a real tendency towards one or two note bass.

I am still waiting to see someone instigate a really good example of truncated transmission line.  In my experience I have found good TL designs to offer really great extension and an ability to "fill the room" even with limited numbers/size of speakers, albeit at low SPL's (bearing in mind to my knowledge no examples exist in the professional sound reinforcement market.  In the past most TL design has been of the "rule of thumb" type with extensive testing and tweaking to achieve desired results, however, George Augspurger and Martin King have in very recent years both produced reliable, mathmatical models, Auspurger via an electrical model and King via a mechanical model, interestingly both's work arrive at similar results and conclusions.  From what I remember I believe that Martin discarded the long held belief that stuffing slowed the speed of the air within the line, he further tested this to prove it was indeed the case and built his model from there.  My understnading means that transmission lines can very succesfully be produced with much shorter lines than previously thought.  Bing that most subs now are crossed over at around 80hz (possibly a little higher) the damping of the ripples should prove less of an issue.

I'd be very interested in your thoughts Tom.

My appologies for drifting way off topic, however, with Tom posting on the thread I couldn't resist!

I actually have no opinion. Transmission lines are something I have read about but have zero experience with.

I am also not much of a fan of bandpass boxes. Most I have heard are "1-note-wonders". A few have been sort of impressive. But not that much.
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Tom Young
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Roland Clarke

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Re: Direct versus Folded Horn Sub enclosures
« Reply #22 on: December 16, 2011, 03:33:36 AM »

I've never built one myself, (I've toyed with the idea a couple of times, just for fun, but time has been the factor), But I do have a PMC sub on a home cinema system.  10" volt driver, cabinet about 3 x 2 x 1 ft, room 30 x 20 ft with a 19ft vaulted ceiling, watching a film like "Sum of all Fears" where when they set the nuclear explosion off the SFX boys decided to have a synth sweep down through the floor.  It's smooth in volume level and as it gets out of hearing range you feel it run through your body.  My listening experience has always lead me to believe that they somehow coupled bass end with rooms better, it might be just lack of colouration due to port/cabinet artifacts.

I must get round to building a couple, just for fun, to go under a couple of band boxes for local 200-300 people shows, not that I do many of that type these days.
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George Dougherty

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Re: Direct versus Folded Horn Sub enclosures
« Reply #23 on: December 20, 2011, 01:04:29 AM »

Many over the years, initially the first I encountered were the Martin "w" bins, IMHO truly awful "boink" boxes, no bottom end at all.  Others that spring to mind are Turbosound, Court Acoustic W bins (they had the advantage of porting to the front that gave the impression of more bass, Martin Wavefront folded horn boxes, none of these ever did it for me, have been using direct radiating boxes for last 15-18 years so I am probably not qualified to talk about anyone's latest developments in "horn" loaded boxes, that being said, I can't see how anyone has overcome the physics to give you a "true" bass response, outside of electronic jiggery.

Just as an afterthought, I am talking about horn's with no direct radiation, not semi hybrid designs.

Same here.  W bins tend to be pretty short horn paths and not what I'd consider a true bass horn.  My Titan 48 is admittedly a big box, but it's about a 14ft path length and effective down to 35 Hz.  Its larger sibling the Tuba 60 is bigger still with control down into the mid 20's.  Takes a big box to render a long path length and a large enough horn mouth to be effective and even then they're always most effective in herds.    Danley's TH115 is supposedly good down to 40Hz flat and will put out some serious bass with its high efficiency.  I'm willing myself to sacrifice the pack space for the clean output and efficiency.  When it comes down to it, mine isn't much larger than a 2x18, it sounds cleaner IMO than any of the 2x18's I've mixed on, it hangs with the average 2x18" in output, I can power 4 off a PLX3602 or larger, and they weigh about 100lbs each.
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duane massey

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Re: Direct versus Folded Horn Sub enclosures
« Reply #24 on: December 20, 2011, 10:16:05 AM »

How big is too big for mobile use? Just curious.

I build front-loaded horns (have been for 35 years), and it has always been my experience that the speaker excursion is significantly less than that in vented boxes. Can't vouch for folded horns, as I haven't played with one in years.

Ivan and others are correct, horns can be directional or not, depending upon the specific design and size. I can say  that a large (96" d x 96 h x 48 w) horn is very directional.
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Duane Massey
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George Dougherty

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Re: Direct versus Folded Horn Sub enclosures
« Reply #25 on: December 20, 2011, 12:16:16 PM »

How big is too big for mobile use? Just curious.

I build front-loaded horns (have been for 35 years), and it has always been my experience that the speaker excursion is significantly less than that in vented boxes. Can't vouch for folded horns, as I haven't played with one in years.

Ivan and others are correct, horns can be directional or not, depending upon the specific design and size. I can say  that a large (96" d x 96 h x 48 w) horn is very directional.
Varies by available pack space and application, IMO.  If it's a little wedding with light background music I'm loading rig into a sedan for, any sub is probably too big. ;)
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Tom Stone

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Re: Direct versus Folded Horn Sub enclosures
« Reply #26 on: December 20, 2011, 08:05:27 PM »

My experience lies completely with commercially made (or copied) bass horns. None of these was big enough to need a forklift. A large enough folded bass horn could provide some off axis attenuation.

Another possible contributor is that if you walked to the outside of split L&R bass horns there would be less combined LF energy, IOW you are walking out of "power alley".

HTH

Could have been I walked out of the power alley.
What do they use in the array subs aren't those Direct or they a little of both ?
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Ivan Beaver

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Re: Direct versus Folded Horn Sub enclosures
« Reply #27 on: December 20, 2011, 08:28:59 PM »

What do they use in the array subs aren't those Direct or they a little of both ?
I am a bit confused by the question.  Maybe you can restate it so it makes more sense?

If you are asking if different types of subs are used-as a general rule, it is not a good idea to mix different types (models and styles-even from the same manufacturer) of subs.

This is because of the different phase response of the different models.  At some freq they will add togethers nicely and at other freq they will cancel either a little or a lot.

In the "perfect" world the most summation you can get is 6dB when you double the number of subs.

HOWEVER, in the "perfect" world, you can get infinate or total cancellation at some freq if the phase is 180° out (at the point of measurement.  Other positions would be different.

All sorts of arrays can be built to direct energy in a specific direction-or to cancel in a certain direction-or change the width of the pattern etc.

It just depends on the end result needed-the tools and space available and the skill/knowledge of the person designing the array.
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Ivan Beaver
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Tom Stone

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Re: Direct versus Folded Horn Sub enclosures
« Reply #28 on: December 21, 2011, 12:48:57 AM »

I am a bit confused by the question.  Maybe you can restate it so it makes more sense?

If you are asking if different types of subs are used-as a general rule, it is not a good idea to mix different types (models and styles-even from the same manufacturer) of subs.

This is because of the different phase response of the different models.  At some freq they will add togethers nicely and at other freq they will cancel either a little or a lot.

In the "perfect" world the most summation you can get is 6dB when you double the number of subs.

HOWEVER, in the "perfect" world, you can get infinate or total cancellation at some freq if the phase is 180° out (at the point of measurement.  Other positions would be different.

All sorts of arrays can be built to direct energy in a specific direction-or to cancel in a certain direction-or change the width of the pattern etc.

It just depends on the end result needed-the tools and space available and the skill/knowledge of the person designing the array.

 I was asking about array subs are they DR type of subs or FH type of subs or a little of both? I know about not mixing two different type subs together.

Just wondering about the array subs like at the AC/DC last tour had a array system, but it was just a loud roar I don't understand any thing they played kind of disappointment to.  :(
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Tim McCulloch

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Re: Direct versus Folded Horn Sub enclosures
« Reply #29 on: December 21, 2011, 02:22:16 AM »

I was asking about array subs are they DR type of subs or FH type of subs or a little of both? I know about not mixing two different type subs together.

Just wondering about the array subs like at the AC/DC last tour had a array system, but it was just a loud roar I don't understand any thing they played kind of disappointment to.  :(

Sub woofer arrays can be made up of either type.  The choice depends on the desired result.
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Re: Direct versus Folded Horn Sub enclosures
« Reply #29 on: December 21, 2011, 02:22:16 AM »


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