Peak Power Handling of Khorn Bass Bin ? ......................

[Guest wdecho]

1 minute ago, wvu80 said:

This guy?  I've seen those before, I guess I didn't realize "back loaded" was the name.  Thanks for the info! 

 

Carl beat me to the punch and yes he is correct. Both the above pictures are "back loaded horns". Probably referred to other names as well. I personally have never heard any myself but from all I have read it does a good job with low bass with little speakers. The big Cathedral speaker uses a 15" driver and It must sound really good for Nelson Pass to purchase a pair. Remember his company sells speakers as well, at least they use to. 

[CECAA850]

9 minutes ago, wvu80 said:

This guy?  I've seen those before, I guess I didn't realize "back loaded" was the name.  Thanks for the info! 

 

Yes.  The picture wdecho posted above is another example.

[dwillie]

  12 hours ago, wvu80 said:

This guy?  I've seen those before, I guess I didn't realize "back loaded" was the name.  Thanks for the info!  

 

 

Like this.  d.  

[garyrc]

"Back loaded" was called "Rear loaded" by JBL.  The 5050s were JBL rear loaded "Scoops."  They were for small theaters, and did not have much deep bass.

 

 

When Todd-AO hired Ampex to provide the marvelous 6 channel sound system for its 70 mm movie process, Ampex farmed out the speaker design and construction to Jim Lansing.  The result is shown below.  There were 5 of these monsters behind the large, deeply curving screen.  A 6th channel for mono surround was switchable to left wall, right wall, rear wall, or all walls.  The switching was either manual or automatic, triggered by a tone below the bass cut-off of the surround speakers.  These are obviously front loaded.

 

[Guest wdecho]

Horns, you gotta love them. If you go to any concert you will see them being used. Makes sense to me if one wants to simulate the "there" sound use horns at home. 

 

As all long threads this one has went on another path. But to answer the OP question, use all the power he wants with his Klipsch bottom end with your ears telling you it is too loud without fear of hurting the speakers. Rock concerts use some of the same speakers used in the Heritage line. If you blow a speaker in the bass unit in your home there is something wrong with you. I remember the movie where Chong is playing his guitar and Cheech comes home and turns it off and says "I hope I can still make babies."

[ClaudeJ1]

On 8/22/2018 at 7:45 AM, mikebse2a3 said:

 

The reduction in modulation distortion for a given amplitude and bandwidth is one of the more important benefits of the KHorn and Jubilee versus some well designed direct radiator systems.

 

Roy demonstrated for some of us in the lab listening room (using all Klipsch designed LF systems) a comparison between the Jubilee and single 15 , dual 15s.  and quad 15s LF systems all with the same K402 HF and all in the same corner and properly balanced by him. What was very obvious to me was how the increase in clarity and resolution tracked with the increase in radiation area of the LF Systems with the KPT415 being the closest to the Jub LF.

 

miketn

Something Don Keele proved out many years ago while at Electro Voice.

[wvu80]

On 8/22/2018 at 7:45 AM, mikebse2a3 said:

Roy demonstrated for some of us in the lab listening room (using all Klipsch designed LF systems) 

 

a comparison between the Jubilee and single 15 , dual 15s.  and quad 15s LF systems all with the same K402 HF

 

and all in the same corner and properly balanced by him. What was very obvious to me was how the increase in clarity and resolution tracked with the increase in radiation area of the LF Systems with the KPT415 being the closest to the Jub LF.  -miketn

Could you expand on that single vs multiple LF system concept in the context of that comparison testing/listening session?

 

In particular I'm wondering what the LF system was, ie a woofer vs sub-woofer setup?  Was this intended to be a living room system or theater setup? 

 

What is a "quad 15"?"  Is that two boxes of two drivers, or a four-driver enclosure?  If the latter that would be a huge box.

 

Feel free to add other observations or comments.  Wish I could have been there.

[Deang]

4 hours ago, wvu80 said:

What is a "quad 15"?" 

It is a four driver enclosure, hence, "KPT415".

[wvu80]

31 minutes ago, Deang said:

It is a four driver enclosure, hence, "KPT415".

Found it.  The KPT415 is an optional enhanced high output mid-bass enclosure used in a 3-way commercial application for a large venue.  Not my usual setup! 

 

Quote

 

KPT-535/4-M

The KPT-535/4-M is perfect for larger venues with limited behind the screen space. An enhanced version of the KPT-535-T with a KPT-415-LF quad 15-inch direct-radiating bass unit, it produces higher output in large auditoriums while still retaining a shallow 24-inch depth. Its three-way design with its mono-amp configuration using a passive crossover system minimizes amplifier numbers while significantly reducing wire runs and labor time.

https://www.klipsch.com/pro/cinema/behind-the-screen/monoamp

 

 

[babadono]

Hey OP  @Cut-Throat the answer to your original question is right here in case you missed it. From the chief himself:

On 8/19/2018 at 12:22 PM, Chief bonehead said:

200 Watts 40-400. AES. 800 Watts peak.

 Yowzer 800w into a KHorn, my ears bleed at 10w

 

 

[CECAA850]

9 hours ago, ClaudeJ1 said:

Something Don Keele proved out many years ago while at Electro Voice.

Makes sense.  More drivers, less cone movement (less distortion) for the same SPL.

[garyrc]

Can we compare the effective radiating area of a horn loaded speaker (say, a Khorn) to some number (1 to ...) of 15" woofers?

 

 

 

 

[CECAA850]

7 minutes ago, garyrc said:

Can we compare the effective radiating area of a horn loaded speaker (say, a Khorn) to some number (1 to ...) of 15" woofers?

 

 

 

 

The area of the exit opening of the horn can be used for comparative purposes I would think.  It's not that simple but close possibly for a conventional front loaded horn.  I'm not so sure about a compression horn.

[ClaudeJ1]

3 hours ago, babadono said:

Hey OP  @Cut-Throat the answer to your original question is right here in case you missed it. From the chief himself:

 Yowzer 800w into a KHorn, my ears bleed at 10w

 

 

Mine too. When I got may first pair of Khorns, I replaced some big Altec boxes I built as a 19-year old for the DJ system I used to set up at college for parties with 300-500 attendees in a large room. I was using Dynaco 400 power amps that were 200 Watts per channel and sounding as loud (and clean) as small bands of the day with their crappy PA systems.

 

Then I built and LED power meter with a ladder network that registered 10 WAtt peaks per channel. Later on, I got a Radio Shack LED power meter that showed 2 Watt peaks being plenty good enough at normal/loud volumes. That is when I realized I didn't need all that power on a Khorn, and downsized my power amplifiers for home since I found 10 Watt peaks to be ear splitting in terms of SPL in my living room.

 

I really wish the industry would rate Power Amplifiers in DB Watts, instead of watts. IOW, Zero DB Watts is 1 Watt, 10 DB Watts is 10 Watts, 20 DB Watts is 100 Watts, and 30 DB Watts is 1,000 Watts. This means 1,000 watts per channel is only 8 times louder than 1 Watt of power, assuming your speakers don't go into thermal compression (which all of them do). Even though this rating is more "real world" and reduces power calculations to simple arithmetic, it will NEVER happen because the MARKETING people would have a heart attack over it because it would make the numbers smaller and less significant, especially to their sales.

 

For example, to convert 100 Watts into DB watts, on a Scientific Calculator, you take the LOGarithm of 100, which is 2, then multiply by 10, which then converts to 20 DB Watts.

 

My Jubilees Bass Bins only see a 4 Watt peak in the bass, upon playback of my "live drums in the room" recording, even with a 32 Hz. boost (per Roy Delgado), which is why I now use these little $25 Chinese Class D amps based on the TI 3116 chip and they sound amazing to all who have heard them. They use a 19 Volt Laptop power supply (about $8 each) and provide a conservative 30 Watts per channel into the approximate 4 ohm load. Since the K-402/TAD drivers are 16 ohms, and are 110 db/Watt efficiency, they draw even less power and can be ignored (typically about 10-50 Milli Watts). Basically you can demo a Khorn or LaScala with the headphone output of an iPhone, which is 20 Milliwatts.

 

So in reality, my 30 Watts per channel amp, both channels driven, on a Khorn Jubilee, is 106 db per watt efficiency for one channel, LOG 30=1.48,  multiplied by 10=14.77 DB Watts. Now add that number to the 106 db/W efficiency of the Jube, you get 106+14.77=120.77 Decibels of output at 1 Meter. But wait, you have 2 channels, so you add another 3 db to that number for a total of 123.77 DB of UNCLIPPED peak SOUND output!!...........................On a drum recording that sounds as live as can be at that point, with ZERO strain on any of the drivers or amps. So at a 4 Watt peak per channel, it's (LOG 4) x 10=6 DB Watts added to 106=112 db per channel, plus 3 more db for the 2 channels for a total of 115 db peaks in my living room on the Jubes, which is truly "stupid loud," for short demos only. When I had my Quarter Pie bass horns, back in Indy, I used a 6 W chip amp to drive the bass bins and it was plenty of power.

 

So with either Khorns, or Jubes, you are, in effect, giving the middle finger to all "hi fi review" writers who think you have to have 500 Plus Watts per channel from $65,000 Power Amplifiers on skinny little overpriced speakers, to make any kind of sound. Now all I need is more of PWK's BULLSHIT buttons to pass out at Axpona shows. If you want the best sound, spend 12 Grand on Jubes with TADs and Digital Xover, and you will only need to spend $80 (including shipping) for your power amplifiers. now THAT is a proper way to spend your dollars to enjoy the cleanest, most detailed music possible on 2 channels.

[ClaudeJ1]

On 8/18/2018 at 5:54 PM, Cut-Throat said:

I am only using the KHorn Bass Bin with Oris Horns on the Top End.

The Specs on the KHorn indicate that peak power is 400 Watts.

But, I am guessing that the Limiting Component here would be the Tweeter and Mid-range.

 

Does anyone here know what the peak power handling is for the Khorn Bass Bin itself? - No Crossover - Just hooked to the Bass Bin?

 

 

Actually the limiting power is always the woofer. According to the rules of thermal compression, most drivers show that effect at 10% of their rated power, although it's not very audible until that is exceeded by quite a bit, but easy to do nonetheless. The signal and power  levels of the mids and tweets are much lower in amplitude naturally by way of the short wavelengths and in the case of Khorns, have a much higher electrical impedance by way of autoformers. This is why they almost never go bad from overpowering.

[ClaudeJ1]

On 8/23/2018 at 6:03 AM, John Warren said:

My ears tell me the Klipschorn bass unit sounds clearer when it's operating on a band-pass (active) filter and supplemented with a sub.

I did this for many years circa 2000.

[John Warren]

On ‎8‎/‎23‎/‎2018 at 8:54 AM, Chris A said:

When you place the Khorn bass bin in a room corner, its low frequency throat radiation resistance significantly increases and extends down to ~40 Hz.  

 

Significantly?  Hardly.

 

The red plot is the impedance of the Klipschorn tucked into a concrete corner.  The black solid plot is a functional form of the Beranek model of the Klipschorn throat using a variable (s-plane)  element to "fit" the simulated throat resistance to the actual data.  The blue dotted line is the model with no s-plane element.  The difference between the dotted line and the solid is a pretty fair assessment of the impedance change associated with horn loading.

 

Radiation resistance is the resistive part of the change.  Between 90 and 200Hz the impedance is about 5 Ohms, i.e. like a resistor.  That's the radiation resistance and where the response peak is measured and the sensitivity a maximum.  The magnitude of the radiation resistance is around an Ohm.

 

You don't have to believe the SPICE simulations, the range where the radiation resistance is active can be eyeballed from the red plot directly.

 

[John Warren]

22 hours ago, wdecho said:

If you go to any concert you will see them being used. Makes sense to me if one wants to simulate the "there" sound use horns at home. 

 

Really?

 

Dual, suspendable 18" direct radiator sub-woofer arrays.

[John Warren]

On ‎8‎/‎23‎/‎2018 at 7:50 AM, Don Richard said:

 

Your observation appears to be based on measurements of a prototype bass horn that did not have improvements that later production units have (opened up "sinus" cavities, etc.). Also the early measurements, before Heyser invented TDS, captured room modes that are clearly present in the graph of the prototype horn in the frequency range you mentioned. You should know better, so I assume you are trolling. 

 

Your assumption is wrong.  The bottom left of the Klipschorn response plot clearly shows "LMS" so it's a cross-correlated MLS response taken at the factory likely by Delgado on a factory, circa 2000, bass horn.  

 

Even if it's an early 50s unit the response with the sinus cavities and smaller throat opening wouldn't be that different.

 

Troll?  Really?  Give me a ******* break!

 

 

[John Warren]

On ‎8‎/‎22‎/‎2018 at 7:45 AM, mikebse2a3 said:

 

The reduction in modulation distortion for a given amplitude and bandwidth is one of the more important benefits of the KHorn and Jubilee versus some well designed direct radiator systems.

miketn

 

Why is it that good engineers, with good test gear just can't seem to replicate PWK's work?

 

https://asa.scitation.org/doi/10.1121/1.3437441

 

Abstract

It has been stated that the total modulation distortion produced by a loudspeaker system is inversely related to the efficiency of the system, and that horn‐loaded systems display less of this distortion than the best direct radiators [P. W. Klipsch, “Modulation Distortion in Loudspeakers,” J. Audio Eng. Soc. 17, No. 2 (Apr. 1969)]. This statement runs contrary to modulation theory, which relates modulation distortion to the amplitude or velocity of diaphragm vibration. Measurements were made both on a high‐quality, full‐range horn‐loaded system and on a large, full‐range direct‐radiator system. Each system was driven with the sum of a 41‐Hz and a 350‐Hz tone to evaluate woofer distortion, and with the sum of a 510‐Hz and a 4.4‐kHz tone to evaluate mid‐range distortion. Output levels ranging up to 110 dB SPL were used. The acoustic output of the speakers was fed to a real‐time spectrum analyzer, and total modulation distortion calculated after the method described by Klipsch. Under all conditions measured, the direct radiator produced substantially less distortion. For example, at 110 dB SPL output, its woofer modulation distortion was 3.9% vs 5.8% for the horn system.