Bull-Nosed Horn Project

RE: Bull-Nosed Horn Project, posted on October 4, 2014 at 00:06:44
amandarae Audiophile Posts: 2591 Location: So.Cal Joined: November 30, 2004	Looking great! Please report back how they sound.

RE: Bull-Nosed Horn Project, posted on October 4, 2014 at 01:47:11
djk Manufacturer Posts: 6135 Joined: June 17, 2000	Notice the new HF horn on top of a LaScala? It sounds better. The LaScala had a K43 (pro woofer) and was vented. The PPSL manifold with four 8's sounded better. The decision was then made to proceed with the good looking speaker (the LaScala was built in 1978 and is now beat up and quite ugly). It will be a while to get it all done, I will get back when I am happy with it.

RE: Bull-Nosed Horn Project, posted on October 4, 2014 at 03:55:43
Scholl Distributor or Rep Posts: 1358 Joined: March 8, 2001	Hope to see some frequency response data on those. They look excellent!!

What 8s are you using? nt, posted on October 4, 2014 at 05:59:08
Scholl Distributor or Rep Posts: 1358 Joined: March 8, 2001	nuttin here

RE: Bull-Nosed Horn Project, posted on October 4, 2014 at 22:29:13

thermionic addictions
Audiophile

Posts: 894
Joined: June 16, 2006

Try this

Try this :)

Cal

http://s56.photobucket.com/user/dkleitsch/media/BullNosedHor

RE: Bull-Nosed Horn Project, posted on October 6, 2014 at 05:41:06
JoshK Audiophile Posts: 820 Location: NJ/NYC Joined: August 3, 2001	Very interesting! Is the slot pointed back and then the air flow turns the corner to the front? ---------------- "When Khruschev said "we will bury you" I don't think he meant with surplus parts." zacster

RE: Bull-Nosed Horn Project, posted on October 6, 2014 at 16:59:19
djk Manufacturer Posts: 6135 Joined: June 17, 2000	Yes, think: Klipsch Belle. They sound fantastic with a simple crossover.

RE: What 8s are you using? nt, posted on October 6, 2014 at 17:01:00
djk Manufacturer Posts: 6135 Joined: June 17, 2000	Tried some SEAS and Silver Flute. SEAS have better bass, Silver Flute have better midrange. May have a driver custom made.

RE: Bull-Nosed Horn Project, posted on October 6, 2014 at 19:10:33

Mr_Steady
Audiophile

Posts: 2042
Location: North Florida
Joined: August 19, 2014

Hi djk,

That is absolutely awesome! Very well done on the bass bins.

Your PPSL's have always intrigued me. Are you crossing it over at 400hz? Getting more than a decade is pretty darn good.

For years I have wanted to ask you how the PPSL compared to the LS in the 200hz to 400hz range. I know they would crush them on the low end.

100db efficiency?

Please tell us your impression of the BMS co-axial drivers. Does the tweeter mess up the sound of the mid driver? Earl Geddes once wrote that co-axial CDs were a good idea that didn't work. I'd like to know your impression. Sorry about this question, but I'se gots to know!

Jamie

Big speakers and little amps blew my mind!

Big Bi-Radial Horn

RE: Bull-Nosed Horn Project, posted on October 7, 2014 at 00:45:07

djk
Manufacturer

Posts: 6135
Joined: June 17, 2000

"Are you crossing it over at 400hz?"

Yes.

"For years I have wanted to ask you how the PPSL compared to the LS in the 200hz to 400hz range."

The PPSL is much, much cleaner.

" I know they would crush them on the low end."

That they do.

"100db efficiency?"

Below 100hz, above 100hz they are about 105dB.

"Please tell us your impression of the BMS co-axial drivers."

They're OK for PA.

"Does the tweeter mess up the sound of the mid driver?"

It's not perfect, but it's OK.

"Earl Geddes once wrote that co-axial CDs were a good idea that didn't work."

Bruce Edgar said the same thing.

RE: What 8s are you using? nt, posted on October 7, 2014 at 03:33:47
Scholl Distributor or Rep Posts: 1358 Joined: March 8, 2001	What company would make them for you? I'd like to get a high powered longer Xmax versdion of the Dayton series 2 Thanks

RE: What 8s are you using? nt, posted on October 7, 2014 at 15:03:22

djk
Manufacturer

Posts: 6135
Joined: June 17, 2000

I have an OEM account with Eminence.

Many other companies will do custom work as well, but the minimums are higher.

Eminence is quite reasonable if you can use off-the-shelf parts, just mix them up a bit.

If you need something completely different you would have to purchase the minimum they would have to buy. If you needed a special spider or cone you might end up owning 1000 of that item to get 100 woofers.

RE: Bull-Nosed Horn Project, posted on October 9, 2014 at 12:01:20
morricab Distributor or Rep Posts: 9180 Location: switzerland Joined: April 1, 2005	I thought the La Scala had a folded horn loaded bass?

RE: Bull-Nosed Horn Project, posted on October 9, 2014 at 14:11:25
djk Manufacturer Posts: 6135 Joined: June 17, 2000	Yes, it does, but because of the small size it has a peak at 140hz and rolls off below that point.

RE: Bull-Nosed Horn Project, posted on October 9, 2014 at 22:48:15

thetubeguy1954
Audiophile

Posts: 6112
Location: Orlando, Fla
Joined: January 7, 2001

Those look absolutely gorgeous my friend. I have my very good friend Paul B. restoring an early pair of TAD 2001 drivers for me as I'm writing this. I can imagine those TAD 2001's mounted to your horns with a pair of Fostex T900a sitting on top of that cabinet crossed in between 8Khz to 10Khz or wherever it is that the TADs 2001's start losing their composure! That should sound quite nice indeed! Oh yeah I love your curved front of the section of your PPSL with four 8's. What a beautiful look. What will you be selling these speakers for price-wise...

I'm listening to: Club de Sol by David Chesky

Thetubeguy1954 (Tom)

Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers

RE: Bull-Nosed Horn Project, posted on October 9, 2014 at 23:18:23

djk
Manufacturer

Posts: 6135
Joined: June 17, 2000

The cabinets were made by Cabinet Solutions at a cost of $2200.

That did not include the work on the HF section, ports, plenum (for the 8's) networks, grills, etc.

The set of eight woofers were about $300, the HF horns are $525 (from Dave Harris), the BMS drivers are about $1400 a pair.

These belong to a friend of mine at work (Dave), and are being delivered to his son in Denver. If any at the RMAF (this weekend) are interested in listening to them, that might be possible.

We will probably be building a couple pair more, and Dave will probably be selling one (or both) pair of his LaScala, and his son works with someone on the Bronco team that may want a set.

I view this set as a work-in-progress, and will hopefully make fewer mistakes on the next two pairs.

Gotcha!, posted on October 10, 2014 at 06:02:45

JoshK
Audiophile

Posts: 820
Location: NJ/NYC
Joined: August 3, 2001

That is cool. Did you model what effect the folded short horn section has? I imagine you can do this in hornresp or akabak. Does the result have more bass than the original lascala, or about the same rolloff?

I see now the rightmost picture in middle row shows the rear expansion, I didn't comprehend what I was looking at at first.
----------------
"When Khruschev said "we will bury you" I don't think he meant with surplus parts." zacster

kinda reminds me of..., posted on October 10, 2014 at 06:20:28

JoshK
Audiophile

Posts: 820
Location: NJ/NYC
Joined: August 3, 2001

This kind of reminds me of a folded version of the "bass" horn used in the late Le'Cleach's inspired (or designed?) Le Grande Castine. Granted they didn't flip one of the drivers and they aren't perfectly parallel, but still slightly reminiscent.

http://www.6moons.com/industryfeatures/grandecastine/1.html

Hmmm....the more I think of it, I don't think they are very similar at all. The LGC's woofers are OB with a horn on one side, whereas your is sealed(?) PPSL with a horn expansion. I'd like to model this some.
----------------
"When Khruschev said "we will bury you" I don't think he meant with surplus parts." zacster

RE: Bull-Nosed Horn Project, posted on October 10, 2014 at 09:27:22

Mr_Steady
Audiophile

Posts: 2042
Location: North Florida
Joined: August 19, 2014

djk,

A couple more questions if I may. You never know unless you ask!

Is there any possibility that the self cancellation of harmonics also extends to the input signal itself?

I'm sure you have listened to straight conical or tractrix mid/bass horns before. How do you rate them as compared to the PPSL and the LS bassbin?

Last night I was listening to Neil Young's, "Live at Massey Hall" on my modified LS's. Half of that album is just him on the piano. You know how when you are close to a piano being played you can hear and feel the sound board resonate? I swear to God it sounded/felt like a piano soundboard was right in the room with me. Totally amazing. I would hate to give that illusion up. I vent this, because terms like, Push-Pull, self cancellation of the second harmonic, and more pronounced third harmonic make alarm bells clang wildly in my head. In fact, they fill me with fear and loathing.

I do try to EQ the 140hz peak, but my equalizer has a 120Hz slide, so I can only adjust it a couple of db.

I guess I am just going to have to take a drive up to Marrieta, GA and take a listen to Les Hudson's versions. Of course, you never really know till you get them home. Do you think that one day you will allow him to build the Bull-Nosed version?

Thanks,

Jamie

Big speakers and little amps blew my mind!

grand castine not a dipole now, posted on October 10, 2014 at 16:21:38

Norman Bates
Audiophile

Posts: 563
Joined: August 9, 2002

They did have it that way they they changed it.

"We also had poor integration between lower and upper horn caused by the proximity of side and front walls with our open-rear bass horn. That never was the case in larger rooms. Now we are working on experiments to partially or totally enclose the 2 x 15" woofers without losing the openness of the sound—one of the strengths of this design—and facilitate integration with smaller rooms............. At this juncture, silence set it and a few months passed. The men were busy with their redesign............ After many trials, we found that the best way to limit these room interactions was to have a slightly deeper bass horn with a single driver instead of the two earlier sidefiring woofers."

http://www.6moons.com/industryfeatures/grandecastine/1.html

RE: Bull-Nosed Horn Project, posted on October 10, 2014 at 23:07:43

djk
Manufacturer

Posts: 6135
Joined: June 17, 2000

"Is there any possibility that the self cancellation of harmonics also extends to the input signal itself?"

Of course not!

"I'm sure you have listened to straight conical or tractrix mid/bass horns before. How do you rate them as compared to the PPSL and the LS bassbin?"

This is what I use on top of my PPSL.

http://i56.photobucket.com/albums/g196/dkleitsch/CoePA-2009.jpg

"In fact, they fill me with fear and loathing."

Just means you need to learn more to lose your fear.

http://i56.photobucket.com/albums/g196/dkleitsch/CoePA-2009.

RE: Bull-Nosed Horn Project, posted on October 13, 2014 at 17:01:26

Mr_Steady
Audiophile

Posts: 2042
Location: North Florida
Joined: August 19, 2014

Hi djk,

"This is what I use on top of my PPSL."

LOL, I gotcha!

In one of your posts you said there were similarities in the arguments about differential amps, and I mistook that for a push pull amp, and I spent some time thinking in the wrong direction. I don't know any of the technical arguments regarding differential amps. I think I read something by Broskie about long tailed pairs. The following is what I came up with vis a vis the PP, and it may carry over to differential as they seem to use a lot of negative feedback. Feel free to skip over it.

PP and PPSL both self cancel the second harmonic, but I believe the PP amps increases the third harmonic, and then multiplies it out to higher odd order harmonics. From what I've read about the PPSL they don't change the already present odd order harmonics. The third may be more prominent because the second is reduced, and then only when the bin is "pushed hard." That's a huge difference. I doubt they will get pushed hard too often in the home enviroment. Oh, maybe once. I say, "Good thing they aren't like PP amps!"

Any bassbin that's 105db efficient, can cover a decade, can go up to 400hz, isn't too big, and is lower distortion than an already low distortion front loaded horn is something worth looking at very closely indeed.

I've been wondering about how to upgrade my bins for a long time. I was leaning toward a straight horn, but it would be too directional being three and a half feet long. I like my horn system to spread the music some. I'm guessing that the PPSL would be less directional?

Another poster mentioned the late great JMLC. Seven years ago I read an interview with him, and he said that he kept two sets of mid horns. One for listening by himself, and one for guests. At the time I thought that was absurd, but now I know exactly what he meant.

What is the difference between four 8", two 12", and two 15" drivers? Just the low cutoff? I noticed in your link that you had the bottom vent on the side.

I congratulate you on your excellent work. It may turn out to be a giant horn killer.

Jamie

Big speakers and little amps blew my mind!

RE: Bull-Nosed Horn Project, posted on October 14, 2014 at 00:57:53

djk
Manufacturer

Posts: 6135
Joined: June 17, 2000

"From what I've read about the PPSL they don't change the already present odd order harmonics."

For the most part.

The low-pass action of the plenum will roll-off higher harmonics at about 12dB/oct, so with careful design you can get some reduction in 3rd (and higher) harmonics at the cost of bandwidth.

"The third may be more prominent because the second is reduced, and then only when the bin is "pushed hard." "

In practice, no.

What does happen is it sounds fine up until the amplifier clips and then the 3rd sticks out like a sore thumb as it goes straight up from the clipping. If of brief duration in live music it seems to be a non-issue, with RAP and its steady drone notes it can sound horrible (use an amp wih a clip-limiter).

"I'm guessing that the PPSL would be less directional?"

At low frequencies, yes.

The Di at higher frequencies increases as much as 3dB as the radiation changes from 2Pi to 1Pi as controlled by the width of the front panel (around 200hz usually).

"What is the difference between four 8", two 12", and two 15" drivers? Just the low cutoff?"

Pretty much.

The quad driver set-up looks way cool, and usually gets "WTF is that" remarks.

"I noticed in your link that you had the bottom vent on the side."

Whatever works the best for you, cosmetics, etc.

"I congratulate you on your excellent work. It may turn out to be a giant horn killer."

Thanks, I don't build bass horns anymore, just mid-bass/midrange and HF horns.

RE: A Silly Question, posted on October 20, 2014 at 17:13:56
Mr_Steady Audiophile Posts: 2042 Location: North Florida Joined: August 19, 2014	Hey Dennis, Just for fun- What would happen to the numbers if you used sealed back drivers? :) Probably ruin the push pull effect. Yes I have an unhealthy fixation with efficiency. I know that now. That's why I'm in this place, for help. Jamie Big speakers and little amps blew my mind!

RE: A Silly Question, posted on October 20, 2014 at 23:00:49
djk Manufacturer Posts: 6135 Joined: June 17, 2000	That is a silly question.

RE: Bull-Nosed Horn Project, posted on October 21, 2014 at 03:46:55
EduardG Audiophile Posts: 284 Location: So. Cal Joined: May 30, 2002	I would love to see how you made the inside of the female horn mold.

High Efficiency Speaker Asylum

Bull-Nosed Horn Project

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