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ClaudeJ1

Quarter Pie Bass Horn: Measured FR, How2Build, and Hornresp

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7 hours ago, parlophone1 said:

Now, he kept LaScalas with him only for a very short time. The reason was the boxy sound from bass bins. Highs and mids to his ears were perfect. But that kicks out of bass bins he could not bear. Just went back to Magies.

 

Was that the peak at 140 Hz that you mentioned?

 

I'm not sure most LaScala owners would consider the bass as being "boxy" sounding, though I think I get what your friend was referring to. It seems that once my ears had been attuned to the resonance peak at 140hz, I couldn't not hear it. I have yet to measure the Q-Pies in my studio, but to my ears there doesn't appear to be any noticeable bass peaks like before.

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10 hours ago, parlophone1 said:

Was that the peak at 140 Hz that you mentioned?

Yep. Some rare Klipsch fanatics put the LaScala II top sections in storage and purchase a pair of K-402 theater horns with 2" Pro Drivers to create an Active 2-way system. This means getting a Digital Crossover with Parametric Equalization and Time Delays to get better phase coherence. As part of the setup as recommended by Roy Delgado, Klipsch's Chief Engineer, there's a PEQ filter with a -7 db attenuation at 140 Hz. to flatten out the bass bin. What does THAT tell you?

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On 1/22/2020 at 4:39 PM, PrestonTom said:

Not to detract from Claude's work, but if you have working Altec 416's they are a valuable woofer that can be used in various ways. Over at DYaudio there are some highly acclaimed designs using that woofer (notably the Oaken cabinets, my spelling might be off). There are a number of choices.

 

Running a simulation is a good idea, but please keep in mind the the Altec 416 was produced for a number of years and not all versions have identical specifications. 

 

Good luck,

-Tom

Those drivers are terrific in horns or bass reflex. I used Altec woofers in some 20 cubic foot cabinets I built when I was 19 years old. The only thing I would add is you need to measure the overall DIAMETER of those woofers because as far as I can remember, they were 16 inches, so you would need to have WIDER RIP CUTS (I would go with 16 1/4 to 16 1/2") to build the Quarter Pies using that woofer. All other dimensions would be the same, so basically you would still rip the lumber the same way and end up with the bass bin a smidge taller laying down. No big deal there. It might cost you an extra sheet of plywood, but you would gain a very SLIGHT increase in efficiency from the extra volume of air in the horn. Measureable, but hardly audible.

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On 6/23/2020 at 10:08 PM, Ray_pierrewit said:

I wonder how many, if any LaScala owners have followed his suggestion?

Not many, apparently. The fools! If only they knew!! LOL.

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On 7/3/2020 at 11:01 AM, Ray_pierrewit said:

Everything cost me less than $400CDN, which has proven to be the best money I've spent since buying my LaScalas over 12 years ago for $800, which still represents my best bang for the buck purchase yet! Guys, this is a no brainer for whoever can afford the space and time to build them!

For Americans, this would be less than $300 US. Keep in mind that the Klipsch AA network is still in use, along with a factory original Klipsch K-33 woofer, so those are already paid for in the older LaScalas.

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4 hours ago, Ray_pierrewit said:

 

I'm not sure most LaScala owners would consider the bass as being "boxy" sounding, though I think I get what your friend was referring to. It seems that once my ears had been attuned to the resonance peak at 140hz, I couldn't not hear it. I have yet to measure the Q-Pies in my studio, but to my ears there doesn't appear to be any noticeable bass peaks like before.

Your ears are correct. Just look at my original curves in the early posts.

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Is there any lower priced Dayton drivers that would work ?


Sent from my iPhone using Tapatalk

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On 1/22/2020 at 4:39 PM, PrestonTom said:

notably the Oaken cabinets, my spelling might be off

 

Onken would be the correct name...

 

 

Hiraga-Onkens-English.pdf

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12 hours ago, Marvel said:

On 1/22/2020 at 4:39 PM, PrestonTom said:

notably the Oaken cabinets, my spelling might be off

 

Onken would be the correct name...

 

 

Hiraga-Onkens-English.pdf 561.96 kB · 1 download

So this "onken" thing is basically a Cornwall using Altec drivers, just like I did when I was 19 years old. I thought this thread was about HORN Bass using the simplest and best of the Klipsch bass horn designs I evolved in to a DYI for everyone with a Home Depot close by? Can you please move it to a Cornwall or Bass Reflex Thread?

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3 minutes ago, ClaudeJ1 said:

So this "onken" thing is basically a Cornwall using Altec drivers, just like I did when I was 19 years old. I thought this thread was about HORN Bass using the simplest and best of the Klipsch bass horn designs I evolved in to a DYI for everyone with a Home Depot close by? Can you please move it to a Cornwall or Bass Reflex Thread?

 

Not at all like a Cornwall...

 

You want it moved? Ask a moderator. I just replied to PrestonTom.

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1 hour ago, Marvel said:

 

Not at all like a Cornwall...

 

You want it moved? Ask a moderator. I just replied to PrestonTom.

Bass reflex 15" driver with a 500 or 800 hz. horn, but with the ports on the side with a 40 Hz. rolloff is just like a Cornwall with symmetrical ports is 99% Cornwall-like and Zero% horn. I was suggesting you start a new thread on a non-Klipsch speaker instead of diluting mine with irrelevance, regardless of whose post you were answering. Let's see if you get 66 pages worth of interest from that. You won't know until you try, so don't take it as a negative, but rather as a positive suggestion for further, more relevant (about bass horns and not bass reflex) discussions, OK?

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Pfffft... I'm happy with my MWMs, thanks.  You inject your posts about your design into other folks threads.

 

Enjoy your day.

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2 hours ago, Marvel said:

 

Not at all like a Cornwall...

 

You want it moved? Ask a moderator. I just replied to PrestonTom.

Guilty as charged, but it's the interest of a forward improvement not backwards like bass reflex. The ultimate/final center channel by PWK ended up as a Belle, evolved from a Heresy to Cornwall because of lower distortion, not requiring lower bass cutoff.

 

The MWM was my favorite woofer section from Klipsch, so you are no stranger to horn bass yourself no doubt. Enjoy the music.

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21 hours ago, carlthess40 said:

Is there any lower priced Dayton drivers that would work ?


Sent from my iPhone using Tapatalk

Yes, the lower price Dayton that would work is the PA380-8 15" Pro Driver at about $70, if you wish to not buy American with Eminence. So you would save $100 on the Quarter Pie build. Even more if you use MDF instead of plywood. You would get that same 50 Hz.cutoff at the bottom with "fatter" bass output at 60 Hz.

 

Because of the 4x higher inductance in that woofer, you would be down by 7 db at 400 Hz. Oh, and it's 8 ohm impedance would require a higher drive voltage for the same output. Not a problem with Active Xover, but you can't use a AA network from a LaScala without dropping the T2A taps by 3 db, thereby increasing the mid and tweet impedance to compensate while cutting the Capacitor Values in half to keep the crossover points the same. Also, you could probably short out the 2.5 mH woofer choke on the AA, since it's not really needed if you were to try a AA network first with the mods suggested.

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I really like the elegant solution that is built into the Q.Pie design.  I just want to backtrack a little and incorporate my list of needs into the Q.Pie and see what happens. My list is not really my list but a collection of knowledge that I gathered on the midbass horn and how it relates to other channels.

 

1.Should be a hypex (hyperbolic???) profile according to Dr. B.Edgar

2.have a single gradual fold (at most) to integrate with mid at 500-600hz

3.play flat down to 80hz at the least, to integrate with subs.

4. have a coverage pattern at the midrange crossover that is complementary and matching the midrange horn at the crossover.

 

How's my list so far? 

Edited by noviygera

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1 hour ago, noviygera said:

I really like the elegant solution that is built into the Q.Pie design.  I just want to backtrack a little and incorporate my list of needs into the Q.Pie and see what happens. My list is not really my list but a collection of knowledge that I gathered on the midbass horn and how it relates to other channels.

 

1.Should be a hypex (hyperbolic???) profile according to Dr. B.Edgar

2.have a single gradual fold (at most) to integrate with mid at 500-600hz

3.play flat down to 80hz at the least, to integrate with subs.

4. have a coverage pattern at the midrange crossover that is complementary and matching the midrange horn at the crossover.

 

How's my list so far? 

 

Just do JWC straight tractrix horns. Plans are around here somewhere. They are awesome from 500-80hz and no folds. .

Here they are last time I had them hooked up.

retro vintage modern hi-fi: Tractrix

Here it is at JC's with a sub...

Impromptu 1,400 Mile Road Trip - 2-Channel Home Audio - The Klipsch Audio  Community

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1 hour ago, noviygera said:

I really like the elegant solution that is built into the Q.Pie design.  I just want to backtrack a little and incorporate my list of needs into the Q.Pie and see what happens. My list is not really my list but a collection of knowledge that I gathered on the midbass horn and how it relates to other channels.

 

1.Should be a hypex (hyperbolic???) profile according to Dr. B.Edgar

2.have a single gradual fold (at most) to integrate with mid at 500-600hz

3.play flat down to 80hz at the least, to integrate with subs.

4. have a coverage pattern at the midrange crossover that is complementary and matching the midrange horn at the crossover.

 

How's my list so far? 

Fine. The Quarter pie will play from 50-600 Hz. easily, but it depends on where you sit, your room, your dispersion requirements, how complex of a build you want, how many drivers vs. a single 15" etc. I like to cross subs much lower than 80 Hz. like 40-60, but that's just me. 80 Hz. is not very low.

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On 7/9/2020 at 11:38 AM, ClaudeJ1 said:

Yep. Some rare Klipsch fanatics put the LaScala II top sections in storage and purchase a pair of K-402 theater horns with 2" Pro Drivers to create an Active 2-way system. This means getting a Digital Crossover with Parametric Equalization and Time Delays to get better phase coherence. As part of the setup as recommended by Roy Delgado, Klipsch's Chief Engineer, there's a PEQ filter with a -7 db attenuation at 140 Hz. to flatten out the bass bin. What does THAT tell you?

 

Go into HornResp and change that parallel section at the back of the LaScala mouth, move the front edge of it to line up with the back edge of the doghouse 'roof'.

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4 hours ago, DirtyErnie said:

 

Go into HornResp and change that parallel section at the back of the LaScala mouth, move the front edge of it to line up with the back edge of the doghouse 'roof'.

then it will be like an FH-1 with a higher cutoff frequency.

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21 hours ago, seti said:

 

 

Just do JWC straight tractrix horns. Plans are around here somewhere. They are awesome from 500-80hz and no folds. .

Here they are last time I had them hooked up.

retro vintage modern hi-fi: Tractrix

Here it is at JC's with a sub...

Impromptu 1,400 Mile Road Trip - 2-Channel Home Audio - The Klipsch Audio  Community

 

Here's that thread:

But looking at the response, it's not flat to 80hz. Looks more like a 130hz horn to me -- can't use that. Also, I have read somewhere that Tractrix is not optimal for midbass horn loading. In fact Bruce Edger pronounced it and I think I'll go along with that. Need hyperbolic or hyperbolic/exponential. So far the Q.Pie is my 1st choice. Like, ClaudeJ1 pointed out, I would also like to cross the subs below 80hz. But I would like to know what type of expansion Q.Pie uses.

Also is the Q.Pie 1/4space or 1/2space horn?

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