OK, So why doesn't Klipsch Make a Horn-Loaded Sub?

[DrWho]

I wouldn't be too confident about those claims...

A single LMS 5400-18 will do 129dB in half-space (outside) in a 4 cubic foot enclosure with an F3 of 34Hz (-10dB at 25Hz). To go anywhere near that low with a horn you're talking a good 10 cubic feet minimum (let's call it 8 for now). I think you would be hardpressed to find a single 8 cubic foot horn that could belt out 135dB with the same frequency response (which is the equivalent cabinet volume for two TC subs). Of course the power requirements are far different...I don't know of any 8000W amplifiers or 110V outlets that can source 80A of current [] - definetly a 220V situation.

If I were building a new permanent overkill outdoor venue I wouldn't hesitate to use direct-radiating bass over hornloaded. Get an array going under the stage and few mains will be able to keep up. And in such situations the power requirements, though insane, won't be a prohibitive issue. Just get a "digital" 3-phase power amplifier.

Anyways - none of the "heritage" can keep up at 130dB (they all poop out at 121dB). The only ones that might come close are the Chorus II, KLF-30, or CF-4 with a peak SPL around 130dB (which requires 1000W). And I think those measurements were taken from in the corner...

[Jay481985]

I wouldn't be too confident about those claims...

A single LMS 5400-18 will do 129dB in half-space (outside) in a 4 cubic foot enclosure with an F3 of 34Hz (-10dB at 25Hz). To go anywhere near that low with a horn you're talking a good 10 cubic feet minimum (let's call it 8 for now). I think you would be hardpressed to find a single 8 cubic foot horn that could belt out 135dB with the same frequency response (which is the equivalent cabinet volume for two TC subs). Of course the power requirements are far different...I don't know of any 8000W amplifiers or 110V outlets that can source 80A of current [] - definetly a 220V situation.

If I were building a new permanent overkill outdoor venue I wouldn't hesitate to use direct-radiating bass over hornloaded. Get an array going under the stage and few mains will be able to keep up. And in such situations the power requirements, though insane, won't be a prohibitive issue. Just get a "digital" 3-phase power amplifier.

Anyways - none of the "heritage" can keep up at 130dB (they all poop out at 121dB). The only ones that might come close are the Chorus II, KLF-30, or CF-4 with a peak SPL around 130dB (which requires 1000W). And I think those measurements were taken from in the corner...

RF-7 no?

Also 8000 rms watts.... hmm crown itech me thinks....... maybe two qsc rmx5050

[TheEAR]

DrWHO,

Heritage speakers are weaklings(damn weak) compared with real sound reinforcement mains used in arrays in large venues.Heritage indeed give up around 120dB dB,sound reinforcement mains can belt over 135dB even pushing 140dB with no problems.

A bass bin will project bass waves with better effect than any direct radiating on a very large space.As pressurising an open space is IMPOSSIBLE when practicality is even the smallest concern.Bass bins directed at you from a 100ft distance will produce a much higher SPL then direct radiating classic sub using even a woofer with 5-10X the piston travel.

Just for fun I've purchased some large Cerwin Vega monitors and a bass bin using dual 18" woofers.Good grief,they may not be the last word in refinement but do they play at inhuman levels with zero stress.Paid $600CAn for two mains and the passive bass bin.Huge MFOS,great for techno and live rock concerts.

Shame on me for enjoying Cerwin vega Pro [:$]

In a closed space the direct radiating would be in a much better position.

[DrWho]

A bass bin will project bass waves with better effect than any direct radiating on a very large space.As pressurising an open space is IMPOSSIBLE when practicality is even the smallest concern.Bass bins directed at you from a 100ft distance will produce a much higher SPL then direct radiating classic sub using even a woofer with 5-10X the piston travel.

If by bass bin you mean horn, then I'll have to disagree...regardless of the type of driver configuration, the polar response is determined by the geometry of the situation. A horn or a bunch of direct radiators with the same "exit" surface area and shape will have the same 'projection'.

Now if you're talking raw SPL or visceral impact at any position within the coverage of the system, then 130dB from a horn or 130dB from a direct-radiator is going to be the same thing (provided distortion levels are similar).

I made the reference to live sound because the SPL's are way insane higher...and the sub to which I was referring would have no problems keeping up with pro-gear - yes, even outside. The whole point being that it would have no problems keeping up with heritage in any situation (which is much less capable than pro-gear).

There are good reasons that all the grand-daddy big venues (including outdoor) are using direct-radiating bass.

http://www.linearray.com/mla6_feature_tour/mft_transducers.htm

http://www.jblpro.com/vertec1/new_vertec/vt_nav.html

http://www.meyersound.com/mseries/milo/m3d-sub.htm

http://www.eaw.com/products/linearray/

Just to name a few []

To achieve controlled directivity the array needs to be large - and in the process the extra drivers just happen to dramatically increase the peak output of the system. But peak SPL isn't much of a concern anymore and it's interesting to note manufacturers pushing the low frequency limit down into the 20's (output gets traded for extension). I can't imagine it being much longer until output below 20Hz is "normal" for a large live concert. Heck, Blue Man Group already pushes 16Hz material. Horns capable of such frequency quickly run into awful time-delay issues.

[TheEAR]

In your links,sure thing,large arrays of subs will simply move so much air and energise the air.Cannot be denied.

And again 130dB is 130dB no matter from what type of speaker is generating.I meant the same woofer used free air and another(same woofer)design using a horn(of adequate size)will best the direct radiating woofer in an open space.After all horns are amplifiers.And Project,where a direct radiating does not have a focused projection.

They can design arrays capable of even 16Hz,they would use larger modules and more of them.

[DrWho]

Even in a budget constrained setting the number of drivers is rarely the limiting factor. Space is usually the bigger issue, and for the same volume a horn takes up you could implement multiple of the same drivers to result in more effective displacement. (In live sound you've got time-propogation and transportation issues and in home audio you've got aesthetics and shipping issues).

I'm not sure I would call an impedance matching device (horn) an amplifier either...it just makes the design less inefficient (implying that it's still inefficient).

[D-MAN]

I agree with Mike. The size required for a true horn of "sub" frequencies would be very large indeed.

That's why most horn subs smaller than refrigerators are not complete horns. Most tend to be undersized and rely on placement (walls, floor, etc) in a half-hearted and half-effective effort to make up the last section and form a mouth of somewhat "proper" size.

This means that most so-called horn-subs tend to be very foreshortened to maintain a "reasonable" footprint. I would go as far as to say "if you aren't appalled by its size, then it ain't a good horn sub".

Unfortunately, this generally entails ehausting the terminus into a capacitive space, rather than extending and maintaining the required expansion that a true horn structure would. Not quite the same as a full size horn in other words. Sort of a pseudo-horn, or partial horn.

The natural result of a foreshortened horn is having a very peaky response - however, this is sort-of acceptable in the case of the subwoofer, since the desired sub frequencies generally would be contained in a single response "peak" in an otherwise very limited and very peaky bandwidth.

It seems a shame to me that someone with a pair of "good" horns would want a horn subwoofer of inferior performance (comparitively) and think that a horn-sub would give them the extra performance typical of a well designed horn speaker that they are used to.

If you really want a sub that badly, get a multiple-driver direct-radiator type, not a partial horn which is a compromise to begin with.

DM

[TheEAR]

To end this thread we agree horn loaded subs in a home environement are not practical and not realistic.

Why build a giant horn loaded sub when you have very good subwoofer designs capable of over 120dB at 20Hz? Nonsense,yes it is.

And even horn speakers(upper registers) in a home are of little use,besides great to use with tube amps. [] Today with the advent of very high quality transformerless switching amps with plenty of good watts,the super efficient low power handling speaker only belongs in old dreamers setups and extravagant people's houses. [] Double one here.

For the record my "grosly inefficient" Dynaudio mains will play almost as loud as the RF7's will providing you have the amp to power them.And the gain in loudness is insignificant at levels where you can damage your hearing.

[Raider]

I think we're all capable of drawing our own conclusions.

And deciding when to end an intelligent exchange of ideas.

[DrWho]

lol

[TheEAR]

I think we're all capable of drawing our own conclusions. And deciding when to end an intelligent exchange of ideas.

Oh my,I sense someone is offended.Then by all means continue arguing.Maybe your conclusion and INTELLIGENT exchange of ideas will lead to a breaktrough product.

[DrWho]

Horns would put the TC SOunds to shame in a environement outside or

in a huge space.As they PROJECT like no non horn loa=ded sub can(no

matter if it moves 1L or 50gallons of air in one stroke).

==================================

Heritage speakers are weaklings(damn weak) compared with real sound

reinforcement mains used in arrays in large venues.Heritage indeed give

up around 120dB dB,sound reinforcement mains can belt over 135dB even

pushing 140dB with no problems.

A bass bin will project bass waves with better effect than any

direct radiating on a very large space.As pressurising an open space is

IMPOSSIBLE when practicality is even the smallest concern.Bass bins

directed at you from a 100ft distance will produce a much higher SPL

then direct radiating classic sub using even a woofer with 5-10X the

piston travel.

==================================

And again 130dB is 130dB no matter from what type of speaker is

generating.I meant the same woofer used free air and another(same

woofer)design using a horn(of adequate size)will best the direct

radiating woofer in an open space.

I don't get it - what stance are you taking? If 130dB is 130dB

regardless of the source and Klipsch Heritage can only do 121dB, then

how is a single TC Sounds 18" LMS-5400 that can do 128dB outside

insufficient?

To end this thread we agree horn loaded subs in a home environement are not practical and not realistic.

Why build a giant horn loaded sub when you have very good subwoofer designs capable of over 120dB at 20Hz? Nonsense,yes it is.

And even horn speakers(upper registers) in a home are of little use,besides great to use with tube amps.

For the record my "grosly inefficient" Dynaudio mains will play almost

as loud as the RF7's will providing you have the amp to power them.And

the gain in loudness is insignificant at levels where you can damage

your hearing.

Actually, I think the point was made (though not explicitly stated)

that horn loaded bass makes more sense in the home where the room helps

with the final registers of the horn's performance and the

time-propogation issues are easily addressed without compromise.

As far as hornloading in general - your comments would make PWK roll in his grave. He spent a good portion of his time proving

that efficiency and sensitivity are inversely proportional. I always

hesitate illuding to direct-radiators as better than horns, which is

why I always bring it back to the cabinet size....Sixteen 90dB speakers

are going to have an efficiency of at least 102dB...perhaps a bit

crazy, but it'll be about the same size as an equivalent single driver

horn - and cost about the same too (wood and time isn't cheap). The

horn would probably be around 110dB, but the direct-radiators would

have 16x the power handling (bringing you back up to more output). Cone

displacement will be about the same for both at the same SPL's.

Btw, SPL = Sound Pressure Level. What do you mean by your comments about "pressurising" the air outside?

Pray, enlighten us with your vast experience and intelligence. Maybe I'm the one going in circles?

[TheEAR]

"pressurising"

In a closed space you can create compression,compress the air in the room(space),outside there are no "walls" to enable you to do so and the "pressure" is only percieved very close to the source(your speakers,subs in this case).

In a closed space stand at any distance from the sub(s)and you can feel the pressure(given you have sub(s)capable of a minimum SPL).In an open space you stand next to the source and then 50-100m from the souce you no longer have the effect you had in a closed space.

Yes I agree that multiple non horn loaded drivers with a radiating area equivalent to the exit area of the horn will give the same effect(SPL)once power handling is taken into account.

[Jay481985]

"pressurising"

In a closed space you can create compression,compress the air in the room(space),outside there are no "walls" to enable you to do so and the "pressure" is only percieved very close to the source(your speakers,subs in this case).

pressure is sound technically.... its vibrations of molecules that produce sound and one must apply a "force" or pressure to create vibration.

In a closed space stand at any distance from the sub(s)and you can feel the pressure(given you have sub(s)capable of a minimum SPL).In an open space you stand next to the source and then 50-100m from the souce you no longer have the effect you had in a closed space.

Yes I agree that multiple non horn loaded drivers with a radiating area equivalent to the exit area of the horn will give the same effect(SPL)once power handling is taken into account.

[TheEAR]

Jay,

This is why in an open space you cannot have "compression",the effect you get in small spaces,where you can use one capable driver and compress the air around you.Serious sound systems in closed spaces can create this effect,in an open area you cannot,unless you would use tremendous arrays and even then you cannot compress the air. at a distance,you can project but to compress...try it .

This was only an argument,and serves no purpose at home.So ...chill out people

[Jay481985]

you can compress open space.... its called why do people have their ears bleed when a bomb goes off near them...... A strong subwoofer does similar principle but no where near as strong though.

[Raider]

I think we're all capable of drawing our own conclusions. And deciding when to end an intelligent exchange of ideas.

 

Oh my,I sense someone is offended.Then by all means continue arguing.Maybe your conclusion and INTELLIGENT exchange of ideas will lead to a breaktrough product.

Offended? Hardly.

Given your capitalization of the adjective "intelligent" and the apparent tone of the associated comment, you may have misinterpreted my sentence regarding "intelligent exchange of ideas" to somehow be exclusive of your contributions to the thread. If so, you couldn't be more wrong. I have actually learned a lot from your comments, not only on this thread, but on several others as well. So I found it puzzlng, and amusing, for you to declare a premature end to the thread that I started. And I found it also interesting that you state your conclusions and understanding applied to your situation, as representative of the forum globally, as diverse as it is. In fact, I found the tone of post #800952 to be so divergent from the helpful and informative posts I have come to expect from you, that I wondered if a troll had counterfeited your identity.

I find the group dynamics of forums fascinating. Its interesting how language, divorced from vocal inflection, facial expression, and body language can so easily be misunderstood.

I have corresponded via PM with DrWho on several occasions regarding potential subwoofers, and he generally summarily shoots down most every idea with those pesky facts. I think he might tell you that I am infinitely more likely to laugh when my ideas are shot down, that to take offense at disagreement. For future reference to anyone reading, if you are ever offended by anything I say, that is definitey not my intent. I'm here to learn from you all, contribute if possible, and to have fun; not necessarily in that order. I reserve the inalienable right to be wrong - I think its in the constitution somewhere.

My normal modality in approaching a problem or opportunity is to identify the factors and principles at play, establish priorities in the context of those variables (which are often mutually exclusive), and then seek a solution that seems to be the best application of those priciples to the opportunity at hand.

Speaker design too is a case-study in tradeoffs, priorities, and compromise. And one of the best examples of diminishing returns that I know of.

The fundamental concepts and physics principles involved in speaker design do not change, and most all were identified, quantified, and developed in the '40's. What does change is the contextual application of these principles. Consider for instance the development and refinement of equalization and its impact on smoothing frequency response. Or the refinement of speaker suspensions to allow longer excursion. Or, as you note, the impact of ever-cheaper power. Or of the implications Moore's Law in the development of FEA, CAD, CAM and its exponential effect on every aspect of design, manufacture, measurement, logistics, etc. Or even economic considerations such as the dispensible income of the average buyer today, and their expectation of ever-greater sound quality and ever-lower prices. While the principles stay the same, the context to which they may be applied changes constantly.

I opened this thread out of genuine curiosity about its subject, and so that the various concepts, principles, and tradeoff's involved could be identified and openly discussed. It also gives a chance for different people to offer what solution they came to, given their own priorities and situation, and I enjoy hearing their reasoning.

I have found this thread to be very informative in this regard, and it has given me opportunity to consider options I had not previously looked at, after acquiring a better understanding the principles involved. For instance, I have considered both IB and arrays, as well as a horn in my adjacent attic space.

The open discussion has also given me a better understanding of perhaps why Klipsch engineers pursued the path they did with the RT12-d and RT10-d. These offer maximum displacement for a given motor strength, take advantage of corner loading, are relatively small for their output, and versatile, though perhaps somewhat expensive. So though they are a compromise in some ways, they do a very good job of adressing several common priorities for relatively small size, deep extension, high sound quality, and substantial power output.

I'm glad you have reached a conclusion that meets your needs and that you are comfortable with, even though it might be different from the majority of horn-lovers here. (BTW, I enjoy Dynaudio speakers in my car, driven by substantial power, emmensely. So I understand your argument, and for that context, for my situation, I chose a similar approach.)

With the number of hits and longevity of this thread (and also of " Bass horn ideas again. A possible build. Need criticism. " in Updates and Modifications, and " Danley Labs DTS-20 On The Way" in this section) I think there is sufficient interest in the subject to continue.

I had the priviledge of hearing Paul Klipsch speak about 30 years ago. Your stated conclusions in #800952 are remarkably similar to what I recall Mr. Klipsch saying were the prevailing arguments and resistance he met from others at the time, before he developed the Klipschorn.

So, yes, constructive discourse may indeed lead to a breakthrough, within a changing context.

I look forward to your continued contributions, should you choose.

Should we meet, maybe at a Klipsch Pilgrimmage, we can enjoy a conversation, inflection, expression, body language and

all. Hopefully less misunderstanding. First round's on me.

[TheEAR]

Raider,

My "declaration" was not serious.On this forum the more threads and the longer they are the better,proves the forum is working.

Sorry if it was taken the wrong way.

[Raider]

Not a problem. As I said, "Its interesting how language, divorced from vocal inflection, facial expression, and body language can so easily be misunderstood." And often humor is the most difficult convey. Sorry I missed the queue. I look forward to learning more from your posts. It's rare to find anyone with as broad an actual experience base with as many subs, even a dealer.

[TheEAR]

Speaking of subs I picked up a RT-10d and a Sunfire D-8(for kicks,its a 9" cube!).I am going to test these Sunday.

Imagibe a 9" cubed subwoofer! Yes it can be called sub,not for largers rooms. [:S]