Jump to content

A K-402-Based Full-Range Multiple-Entry Horn


Chris A

Recommended Posts

45 minutes ago, ClaudeJ1 said:

A "little while" is an understatement. I spent a week on Jubes alone.

 

Well, what I'm really saying is that the crossover filter overlap for an MEH is a lot different than separate bass bin and HF horn aperture configurations.  It took me a little time to see this, measure it, and listen to it.  But once you see it and realize that there aren't any audible artifacts and why there aren't any artifacts, the light bulb comes on.

 

It helps to have something to measure while doing this rather than unsupported statements, etc.  I've found that there is actually more bad information surrounding horns and their drivers than good, so that's why I tend to go back to Beranek, Olson, and perhaps even Geddes, as well as listen carefully and see what others have done using MEHs.  There are way too many superstitious beliefs surrounding horn loudspeakers. 

 

I believe that a big awakening is coming that really should shake up the high-end audiophile loudspeaker business, especially when it's widely realized that the patent thing is no longer an issue. I'm not sure that anyone that hasn't heard them (i.e., the Danley Synergies or K-402-MEH) can truly understand what the big deal really is--in controlling polar coverage down to below 100 Hz as well as effectively eliminating modulation and compression distortion, and having almost minimum-phase performance using IIR filtering only, i.e., not having to use FIR filters.  There isn't anything else that can compete, especially in terms of their small size relative to high-end audiophile speakers.

 

Chris

  • Like 2
Link to comment
Share on other sites

On 9/15/2018 at 5:38 PM, Chris A said:

I always use one loudspeaker at a time, i.e., mono, when listening for sound quality differences in loudspeakers, including the case of the K-402-MEH prototype.  I learned that lesson from Roy using mono speakers in listening tests in Hope years ago when listening critically for differences in loudspeakers and their setup.  Stereo always disguises sound quality issues.  This is why an array of five loudspeakers positioned around a listener always seems to sound better--even if using much poorer performing loudspeakers.

 

The K-402-MEH occupies the center position in my array.  But I've also listened to it in the corner, both on the floor and elevated to the height of the Jubilee K-402.  The comments I made above were based on all those listening positions.  The K-402-MEH picks up almost 12 dB of bass response at 40 Hz in a room corner relative to its performance in the elevated center position.  The corner loading case was EQed again to match performance as in the center case. 

 

All loudspeakers that are moved to a corner position need to be re-EQed to compensate for the pick up in bass response (which thus lowers bass distortion levels in the case of the corner loading).  This is well documented in PWK's writings.

 

Chris

Chris would you recommend using a bigger amp for the center and EQing the center to match the bottom end of the left and right when they are in the corners?

Link to comment
Share on other sites

6 hours ago, ellisr63 said:

Chris would you recommend using a bigger amp for the center and EQing the center to match the bottom end of the left and right when they are in the corners?

I don't need any more than a 45 w/channel amplifier for the center MEH in my setup but you could certainly put a higher power amplifier on the woofer channel if you wish.  There are two 15" woofers there that are rated at least at 100 w/channel each.  Remember that there are no passive crossover losses to worry about.  Each amplifier in the current tri-amped setup behave like they have at least twice the output power relative to using one in monoamping mode powering all the drivers plus a passive crossover.

 

The compression driver channels (for the dual-diaphragm BMS 4592) really don't need much power.  I'm using a Crown D-75A (rated at 45 W/channel), but any 10 w/channel amplifier--or even less power--would be more than sufficient.

 

Chris

  • Like 3
Link to comment
Share on other sites

7 hours ago, Chris A said:

.  I'm using a Crown D-75A (rated at 45 W/channel), but any 10 w/channel amplifier--or even less power--would be more than sufficient.

 

This is precisely why I'd like to see ALL amplifiers rated in DBwatts, but it marketing departments will never let it happen. A 10 W amplifier is a 10 DBwatt amplifier. So if you add 10 DBwatts from the amp  to the 112-118 db BMS driver rating, you get from 122 to 128 DB of peak, unclipped output with that 10 Watts ins a single channel. Add another 3 db for stereo, so it would be 125 to 131 db sound pressure. I guarantee, that if you listen at modern OSHA approved levels of 85 dbA sound pressure in your sweet spot, you will be down in the 10-30 milliwatt range on a K402. Electrical amplification Power is NOT the issue here.

  • Like 3
Link to comment
Share on other sites

When we had my HT up and running...I would tell people we were at about 1 watt on peaks when listening at reference levels. They would not believe me so I showed them the stack of Yamaha pro amps, and explained the green LED that was flashing would turn on when it saw a signal of 1 watt. this was for the horns, and bass bins.

  • Like 1
Link to comment
Share on other sites

26 minutes ago, ellisr63 said:

When we had my HT up and running...I would tell people we were at about 1 watt on peaks when listening at reference levels. They would not believe me so I showed them the stack of Yamaha pro amps, and explained the green LED that was flashing would turn on when it saw a signal of 1 watt. this was for the horns, and bass bins.

OK, so why did you ask Chris about a bigger amp when you already knew the answer from your own experience? LOL.

That being said, in the days of really good, cheap power from chip amps, we have all worried about having too low of power for those big boom moments in HT, right?

  • Like 1
Link to comment
Share on other sites

22 hours ago, Chris A said:

helps to have something to measure while doing this rather than unsupported statements, etc.  I've found that there is actually more bad information surrounding horns and their drivers than good, so that's why I tend to go back to Beranek, Olson, and perhaps even Geddes, as well as listen carefully and see what others have done using MEHs.  There are way too many superstitious beliefs surrounding horn loudspeakers. 

 

I believe that a big awakening is coming that really should shake up the high-end audiophile loudspeaker business, especially when it's widely realized that the patent thing is no longer an issue. I'm not sure that anyone that hasn't heard them (i.e., the Danley Synergies or K-402-MEH) can truly understand what the big deal really is--in controlling polar coverage down to below 100 Hz as well as effectively eliminating modulation and compression distortion, and having almost minimum-phase performance using IIR filtering only, i.e., not having to use FIR filters.  There isn't anything else that can compete, especially in terms of their small size relative to high-end audiophile speakers.

 

I agree wholeheartedly with this notion. Tom Danley himself mentioned he wanted his speakers in the home, but his partner doesn't agree. Look how few people get Jubilees for the home now, which is the best Klipsch has to offer (Palladiums anyone?).  So, they could be right. I think AESTHETICS of the high end market trump "great big sound" every time, if you want to sell many speakers. I'll be Klipsch sell way more little speakers than big ones also. In fact, the Heresy save Klipsch and Associates (PWK's company) from bankruptcy many moons ago. Man does not live on bread and Klipshorns alone!

Link to comment
Share on other sites

7 minutes ago, ClaudeJ1 said:

I think AESTHETICS of the high end market trump "great big sound" every time, if you want to sell many speakers.

 

Years ago I found a Website that contained page after page of photographs of horn loudspeakers. For the most part they all had two things in common: they were big, and they were ugly.

 

The Klipschorn had many contemporary competitors, some arguably better performers. But they're all gone except for the Klipschorn. Why? Because the Klipschorn is beautiful (in addition to offering great sound quality), while the others were ugly (in addition to sometimes offering great sound quality).

 

Add to that the fact that people don't want big loudspeakers taking up the precious real estate in their living rooms, and horns (as well as large direct radiators) are doomed. People want tiny soundbars that fit neatly under their TV sets and rattle impressively on anything below 100 Hz. They want anything as large as a Klipschorn to have a glass front to display their fine china.

  • Like 1
Link to comment
Share on other sites

OK, so why did you ask Chris about a bigger amp when you already knew the answer from your own experience? LOL.
That being said, in the days of really good, cheap power from chip amps, we have all worried about having too low of power for those big boom moments in HT, right?
The reason I was asking is...
In my old room I never boosted the bass on the Qpies, and in the new room I will be running the K402 MEH. I am pretty sure I will have plenty of power, but with the old room being around 4,000 cubic feet, and the new one being around 24,000 cubic feet we have a substantial difference in size...hence my question. Once the B&O amps are bridged so I can run in balanced mode...I will have 170w per horn, and 450w for bass. I am pretty sure I will have a ton of power, but it gets eaten up pretty quickly when you are boosting bass. Lol

Sent from my SM-T550 using Tapatalk

  • Like 1
Link to comment
Share on other sites

On 10/17/2018 at 7:10 AM, ClaudeJ1 said:

This is precisely why I'd like to see ALL amplifiers rated in DBwatts, but it marketing departments will never let it happen. A 10 W amplifier is a 10 DBwatt amplifier. So if you add 10 DBwatts from the amp  to the 112-118 db BMS driver rating, you get from 122 to 128 DB of peak, unclipped output with that 10 Watts in a single channel. Add another 3 db for stereo, so it would be 125 to 131 db sound pressure. I guarantee, that if you listen at modern OSHA approved levels of 85 dbA sound pressure in your sweet spot, you will be down in the 10-30 milliwatt range on a K402. Electrical amplification Power is NOT the issue here.

One more thing. To keep apples to apples comparison.........what would be the exact "stereo 85 db in sweet spot" power level for a super efficient compression driver on a K402 at, say 112 db/1watt input or "Zero DBwatts?"

 

There are 2 drivers in stereo, so we can add 3 db for the second driver which doubles the sound pressure for a starting point of 115 db/1 Watt input at a 1 meter distance from the driver voice coil. But that's simply "stupid loud," so we need WAY less than that. So assuming that we are sitting about 13 feet away from those drivers (presumably i corners), we are now at a 4 meter distance, which, in theory should drop us 6 db per doubling of distance from the original 115 db@1 meter. Since we have gone from 1 to 2 to 4 meters, we should now be 12 db down from the original sound pressure level, or 103 db at our listening position (real world wall reflectivity, room gain, and reverberant field would NOT let us do this simplified analysis, but let's ignore that for a moment). Keeping going with all these power requirement scenarios, let's say we want to listen at an average of 83 dbA weighting on a sound level meter at our sweet spot, that is a minus 20 dbW of power requirement or 1/100th of a watt, or 10 milliwatts, which is exactly what I used to measure when I started caring about this stuff decades ago.

 

When I visited Paul W. Klipsch at his home, he played me some of his symphony recordings. He told me all you needed was +17 db of headroom in the amplifiers. From a man who measured everything, I had no reason to doubt his statement, since a full scale Symphony Recording is WAY more dynamic than any commercial pop or jazz recording, it's a safe bet to use his number as a "crest factor" in the home. Even if we round this number up to an even +20 db, or 100 times the nominal power, we will never need more than 1 WATT for a modern 2" compression driver with a huge, heavy ceramic or modern smaller/lighter NEO magnet!!

 

So basically it's a minus 20 db situation (1/100th of a Watt) from the original 1 watt per driver (times 2 channels) and a plus 20 db situation for headroom (100 times 1/100 th of a watt) for worry free listening.

 

So I guess what I'm saying is even a 10 Watt amplifier on a K402 and 2" driver of any brand is OVERKILL!!

 

The extra 2 db you think I'm ignoring would easily be made up by the reverberant field which would now dominate the sound by 80%, requiring even LESS power than my math points out!!

  • Like 3
Link to comment
Share on other sites

Interesting reading here on this thread of the  true dynamics of a horn based system,  including Danley's designs.  Whenever I wan to hear a great demo of a multiple entry type horn based speaker, I am reminded of this guy's DIY Synergy design in his vid.   The effortless clarity of it, is fairly impressive, especially when you factor in the distance from the mic. 

 

  • Like 1
Link to comment
Share on other sites

On 1/10/2016 at 6:48 PM, Edgar said:

 

That just means that the anomaly is minimum-phase, which isn't all that uncommon in the real world.

 

 

I have found the same from many Hornresp simulations. Also, reactance annulment really only applies to exponential horns, and even then doesn't necessarily give the most desirable response. Back chamber can be too small or too large, but there is a great deal of latitude in-between.

 

I found this to be true on my Quarter Pie and Super MWM simulations.

Link to comment
Share on other sites

3 hours ago, ClaudeJ1 said:

So I guess what I'm saying is even a 10 Watt amplifier on a K402 and 2" driver of any brand is OVERKILL!!

This is true for the compression driver channel.  I've never needed much out of the 15 w/channel First Watt F3 amplifier powering the TADs in the left/right Jubs--it has a lot more than I'll ever need in a home-sized listening room.  However for the dual 15" woofers when the MEH is located mid-wall and EQed for flat response down to 31 Hz, you can use more power. 

 

With the MEH in a corner, it picks up approximately 10-12 dB of bass at 40 Hz, so its bass response performance is equivalent to the Jubilee or Khorn bass bins in corner loading.  They really like corner loading if you can provide it but they do extremely well without corner loading. 

 

The advantage of the MEH is that you can use it mid-wall elevated above the floor in addition to corner loading-like a Jubilee or Khorn.  Having that center position with flat bass response to 30 Hz is a big deal in terms of bass coverage in-room, even with its base elevated above the floor about 30 inches as I have it currently. 

 

The K-402-MEH will also do quite well in your 25Kft^3 room in center position, too, Ron.  It's got that much clean reserve bass capability--just like like the KPT-942 has, i.e., the K-402-MEH uses dual 15" woofers and 2" compression driver just like the KPT-942 uses.

 

3 hours ago, Shiva said:

Interesting reading here on this thread of the  true dynamics of a horn based system,  including Danley's designs.  Whenever I wan to hear a great demo of a multiple entry type horn based speaker, I am reminded of this guy's DIY Synergy design in his vid.

I can tell you first hand that it's a bit more convincing in real life than via YouTube.

 

2 hours ago, ClaudeJ1 said:

I found [the design's indifference to back chamber reactance annulling] to be true on my Quarter Pie and Super MWM simulations.

I did, too, for the K-402-MEH which is why I didn't bother with trying squeeze every last ounce of performance out of it...because I don't have to.  I configured the K-402-MEH bass section such that it is de-rated to the point that the two 15" woofers (and DSP crossover to EQ everything flat) works without any audible downside. 

 

This is the same thing that Danley does with its Synergy designs.

 

Chris

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

  • 2 months later...
  • 2 weeks later...
On 11/15/2016 at 11:03 AM, Chris A said:

If we're at a point where we can step back and look at the lay of the land...here's what I currently see from my knothole:

 

Basically all of the ongoing multiple entry horn (MEH) DIY work is on smaller horns that lose their pattern control around 500 Hz, e.g.,

 

http://www.diyaudio.com/forums/multi-way/285030-bookshelf-multi-way-point-source-horn.html

http://www.diyaudio.com/forums/multi-way/291160-my-synergy-corner-horn-bass-bins.html, and

http://www.hificircuit.com/community/threads/index-of-diy-synergy-and-unity-horns.23/.

 

Additionally, these efforts haven't discovered the benefits of using 2" output compression drivers: they all still use 1" drivers. Some are still trying to wedge in midrange drivers like DSL Synergies that are meant for outdoor stadium use (i.e., extremely high SPL that requires separate midrange drivers). 

 

But these are not the best choices that they can make.  There are remaining problems using direct-radiating woofers--and most are vented bass reflex designs (having their own issues sonically integrating with those smaller MEH horns).  Most of those small horn designs are completely ignoring those issues.  And the "small loudspeaker crowd" generally wants to believe that smaller loudspeakers are "just as good" and "a better fit for their rooms". 

 

In reality, however, the K-402-MEH performs better than any smaller loudspeaker array in very small rooms. Just like Roy mentioned elsewhere--small rooms actually require large mouth horns to keep the early reflections off the nearfield walls.  The sonic benefits of using a single horn full-range K-402-MEH in a cabinet that's about the size of a La Scala II are noteworthy.  They don't require a separate woofer or horn-loaded bass bin, and their bass extension is that of a Jubilee bass bin--and arguably cleaner than the Jub bass bin.

 

And those same K-402-MEHs can fill very large home theater rooms without breaking a sweat...

 

Chris

 

https%3A%2F%2Fwww.audioxpress.com%2Fasse

 

Over the past 5-10 years, I'm starting to see compression drivers that are (finally) pushing the performance envelope. Up until 2009 or so, you basically had two options:

1) a lot of compression drivers that can cover four octaves that cost about $150

 

2) a handful of beryllium compression drivers that can cover 4.5 octaves that cost about $1000

 

We're *finally* seeing some affordable compression drivers that can do 4.5 octaves, such as the Eminence N314T that's pictured above.

 

That IS compelling for a Unity horn, something similar to the SPL RUNT: an 8" woofer combined with a single compression driver. The original "RUNT" used a BMS 4550, and as I understand it, was one of the reasons that BMS became ubiquitous with the DSL speakers.

  • Like 2
Link to comment
Share on other sites

I've always been looking for lower cost compression drivers that can do the job without significant 10-20 kHz non-pistonic mode "chatter".  Thanks for the heads up.  I see that's a 1.4" driver, so a custom horn will be needed (i.e., not a K-402) to reduce the throat size down to that diameter.  (I generally don't really like bolt-on throat adapters, but that's certainly an option if the K-402 throat is properly "filled in").  That's not really an issue, but it puts further pressure on the mold maker...

 

When you look at the TAD TD-4002, you are really looking at a 1.5" throat with a bolt-on snout. So 1.4-15" diameter is apparently the "sweet spot" diameter driver for this kind of duty. 

 

I was not aware that the Runt used a BMS driver.  Thanks for that info.

 

Chris

Link to comment
Share on other sites

Chris,

   I seem to remember that at one point you were working on an MEH kit were you not?  I believe you were talking about something that could get a similar result without having to cut holes in a K-402.  Is that still in the works?  I would love to build a set of MEHs, but I have a tough time spending $2000 on horns just to drill into them.  If not, I may try to cobble up something myself.

 

Thanks!

 

Link to comment
Share on other sites

On 10/18/2018 at 10:57 AM, ClaudeJ1 said:

So I guess what I'm saying is even a 10 Watt amplifier on a K402 and 2" driver of any brand is OVERKILL!!

I just set up some K-402's with TAD drivers. The power amp is a Single Ended Tube Amp putting out a whopping 3 Watts per channel. Perfect for a 16 ohm TAD driver!! and it sound exquisite!

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...