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


ClaudeJ1
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On 2/20/2016 at 7:56 AM, ClaudeJ1 said:

Well, it's in post #1 in RED. The Eminence Kappa 15C is my favorite, even though my original design used EVM 15L woofers, which are very good also. The 15C 4 ohms, so it draws more power from the amp to try and keep up with the treble section more easily, and it has slightly better response in the midrange than a K33 or it's replacements, Also, it's very affordable and has lower and more defined bass response. IOW, the best balance of performance and price.

Hi Claude.  Just quoting you to alert you to my reopening the thread.  Thanks for the awesome design.  My primary question is whether or not I can expect midrange response that goes up higher with your design as compared to the FH-1 with 15C that I own?

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11 hours ago, Tizman said:

Hi Claude.  Just quoting you to alert you to my reopening the thread.  Thanks for the awesome design.  My primary question is whether or not I can expect midrange response that goes up higher with your design as compared to the FH-1 with 15C that I own?

I can easily run simulations with any woofer you like, since I still have the Quarter Pie model on one of my computers. Based on experience and measurements, the EVM 15L has the best high frequency response in a horn and 600 Hz. is not a problem. If you do listening tests and distortion measurements on a K-402, you will find that the compression driver WINS at 600 Hz. vs. any Woofer driver.

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On 11/6/2020 at 12:17 AM, muel said:

I'm also a bit concerned pulling the mid and tweeter forward too much from the bass horn.  I've got the tweeter mounted to the mid frame so that those two drivers are aligned.  Ideas? Thoughts? 

It depends on how sensitive your ears are to time delays/phase response. PWK didn't believe in it. I've had both, and I do.

 

So it's a quasi religious answer to a simple question.

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  • 4 months later...
On 11/12/2021 at 11:08 PM, Tizman said:

I know that this is borderline, but what would be my best path if a higher hand off is desired?  What driver is best, and what mods, if any, can be applied to the QP to best achieve that higher crossover?  I don't mind losing a bit on the bottom to achieve the higher crossover point.  Thanks to Claude for the awesome design!      

Not sure if I answered this before, but if you go active, then the best driver would be a pair of EVM 15L's (not B). You could do a 2-way with a Faital Pro 1.4" driver or an Eminence 314X Crossing at 800 Hz. That would be a very good sounding 2-Way system. Not as good as 3-way but close enough for Rock Listeners!

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  • 1 month later...

Hello! I've been reading through this thread for a while, and I finally pulled the trigger on a pair of K-402's with the K691 drivers. I'm currently using them with some Electrovoice Eliminator 1's with Kappa 15c's in them - the EV 15L's are being reconed, so I've got two options for the woofers. I can see what all the hype is about the K-402's - they are simply amazing! I had a pair of La Scala's with ALK universals and the bass bin mod, but began to aquire some large format horns (JBL 2365's, 2353's) and decided to let the La Scala's go when I found the Eliminators - they are 37" wide on their side and matched up to the K-402's better. I'm running my current setup with a Onkyo DTC 9.8 preamp, dbx driverack 260, and a pair of Crown D-75's.

 

I am planning on building the Q-pies, but I'd like to make them a bit taller so the K-402's are at ear height. With them sitting on the Eliminators on their sides (22" high), they are just the right height. My question is, can they just be built 22" high, or would that mess up the horn flare? Also, I'm considering building the "chimney" or "L" version shown earlier if that would allow the horn to be built at 22" high. If I build the chimney version, could I just build the chamber/throat section (15 1/2" square) and put that on the top of the q-pie with a 45 degree baffle? If I build the q-pies 22" high, I could make the chimney section 63" tall and still have a few inches clearance in the corners. I'm not familiar with horn design, and don't know if this extra height would even give much extra bass extension. Any help here would be greatly appreciated!

 

Also, does anyone know what the lower limit is on the K691 driver? I'd like to cross as low as possible, and I don't play at crazy loud levels, 400 hz?

 

Thanks!

Dennis

K-402 w Eliminator.pdf

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  • 1 month later...

It is crazy that it has taken me so long to finally get these built and installed in my room!  I started cutting wood for this over 7 years ago... finally completed over a year ago only to sit in the garage.  A couple of fellow audio nuts helped me carry these upstairs and also move the La Scalas out to the garage for new veneer or Duratex.  

 

WHY did I wait so long?! 

 

This sounds awesome!   Smoothed out the bass and seems to add another octave down.  It is so much smoother and clearer on the bottom end!

 

I thought the dispersion would be a bit narrow having these up on end like this.  The smallest adjustment of toe-in seemed to have a big effect.  Quite a bit of listening and adjusting and all of a sudden they just lit up the room!  It was actually that dramatic.  It nailed it not only for the sweet spot (what I mainly care about) but most of the room.  

 

There was a bit of "chesty" resonance maybe around the lower registers of the male voice.  It was suggested to drop a pillow at the end of the horn and that resonance was gone.  I added some NoRez padding from GR Research... it helped a little but not nearly as much so I put the pillows back.   The family wants the pillows back on the couch but I don't think that will happen too soon.  

 

The mid horn and tweeter assembly is sitting on a brace/shelf that is the exact height of where they were sitting on top of the La Scalas with a slight tilt down.

 

Yeah, I'm pretty happy!

 

Oh and for all the help I owe thanks to @paul79, his friend Jered, and certainly @ClaudeJ1!

 

QpieF1.jpg

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40 minutes ago, muel said:

Smoothed out the bass and seems to add another octave down.  It is so much smoother and clearer on the bottom end!

It is a full octave from the curves. 5.5 foot horn vs. barely 2.7 from a LaScala. Did you use a Kappa 15C?

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SO here is the hardware installed - 

Network: Dean's Aletheia Audio Super AA networks w/ OIMP V-Caps
Tweeter: Beyma CP25 
Mid: BMS 4592ND-MID Drivers 
Mid Horn: Fastlane Audio Eliptrac 400 Horns
Bass: Eminence Kappa-15C

 

I'm considering having a tweeter shootout.  This seems mostly a flavor thing... the sizzle on your steak... the Beyma does a beautiful job (to my taste) with cymbols and trumpet highs.  It sounds so natural and just the right tone but maybe it has a bit more distortion?  

I have an attenuator from ALK so I can knock down the tweeters that are a bit too efficient.  Here is my list so far I will try out:

K-77
Crites CT-125
B&C DE-10 with stock horn  (think I bought these from Claude way back)
B&C DE-120 with Fastrac horn

 

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It is crazy that it has taken me so long to finally get these built and installed in my room!  I started cutting wood for this over 7 years ago... finally completed over a year ago only to sit in the garage.  A couple of fellow audio nuts helped me carry these upstairs and also move the La Scalas out to the garage for new veneer or Duratex.  
 
WHY did I wait so long?! 
 
This sounds awesome!   Smoothed out the bass and seems to add another octave down.  It is so much smoother and clearer on the bottom end!
 
I thought the dispersion would be a bit narrow having these up on end like this.  The smallest adjustment of toe-in seemed to have a big effect.  Quite a bit of listening and adjusting and all of a sudden they just lit up the room!  It was actually that dramatic.  It nailed it not only for the sweet spot (what I mainly care about) but most of the room.  
 
There was a bit of "chesty" resonance maybe around the lower registers of the male voice.  It was suggested to drop a pillow at the end of the horn and that resonance was gone.  I added some NoRez padding from GR Research... it helped a little but not nearly as much so I put the pillows back.   The family wants the pillows back on the couch but I don't think that will happen too soon.  
 
The mid horn and tweeter assembly is sitting on a brace/shelf that is the exact height of where they were sitting on top of the La Scalas with a slight tilt down.
 
Yeah, I'm pretty happy!
 
Oh and for all the help I owe thanks to [mention=50548]paul79[/mention], his friend Jered, and certainly [mention=20774]ClaudeJ1[/mention]!
 
QpieF1.thumb.jpg.fd0014c80d7a24b3f8a59d0dce167f57.jpg

How well would these work with the klipsch k-510 horns ? I has thinking of setting the pies up just like you’ve done, now I know it works well.
The room is like to build the pies for is 13’ wide and 26’ long
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Turned out very well, congratulations. 😍

How is the sound at lower listening levels?

 

I was planning a 2-way system, with only Faital LTH142 horn and their 1.4 driver, plus Q-pies. Then Claude designed SMWMs, then other thing happened including moving to a small apartment, and now I even can not squeeze QPies in that room. So I ended with some bookshelves. How things can go off 😔

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22 hours ago, carlthess40 said:

I has thinking of setting the pies up just like you’ve done, now I know it works well.

I had MWMs (the dual 15 inch cabinets) set up this way in my room and they sounded GREAT! Smooth, even bass no matter where you were in the room.

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On 7/14/2022 at 12:09 PM, muel said:

It is crazy that it has taken me so long to finally get these built and installed in my room!  I started cutting wood for this over 7 years ago... finally completed over a year ago only to sit in the garage.  A couple of fellow audio nuts helped me carry these upstairs and also move the La Scalas out to the garage for new veneer or Duratex.  

 

WHY did I wait so long?! 

 

This sounds awesome!   Smoothed out the bass and seems to add another octave down.  It is so much smoother and clearer on the bottom end!

 

I thought the dispersion would be a bit narrow having these up on end like this.  The smallest adjustment of toe-in seemed to have a big effect.  Quite a bit of listening and adjusting and all of a sudden they just lit up the room!  It was actually that dramatic.  It nailed it not only for the sweet spot (what I mainly care about) but most of the room.  

 

There was a bit of "chesty" resonance maybe around the lower registers of the male voice.  It was suggested to drop a pillow at the end of the horn and that resonance was gone.  I added some NoRez padding from GR Research... it helped a little but not nearly as much so I put the pillows back.   The family wants the pillows back on the couch but I don't think that will happen too soon.  

 

The mid horn and tweeter assembly is sitting on a brace/shelf that is the exact height of where they were sitting on top of the La Scalas with a slight tilt down.

 

Yeah, I'm pretty happy!

 

Oh and for all the help I owe thanks to @paul79, his friend Jered, and certainly @ClaudeJ1!

 

QpieF1.jpg

 

Those look really nice whe way you mounted the Elliptrac horns.

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23 hours ago, carlthess40 said:

How well would these work with the klipsch k-510 horns ? I has thinking of setting the pies up just like you’ve done, now I know it works well.
The room is like to build the pies for is 13’ wide and 26’ long

I had my Q Pies vertical with ZXPC 10x18" and BMS 4592-NDs. I had the horns mounted like carlthess40. This was quite good. I imagine K-510s would also work well.

I now have the Q Pies laying down with K-402s and AXI2050s on top, even better.

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On 7/18/2022 at 5:09 AM, parlophone1 said:

Please,

describe "better" in more detail

I am not good at describing the sound of speakers, but I can relate what I hear.

I have a IB subwoofer system, 2 manifolds with 2 18" drivers in each. This sub is flat to 12Hz with very low distortion and prodigious output.

Woofers are Claude's Quarter Pies with Kappa 15C drivers. These are very articulate. I never knew how much clarity I was missing until I tried horn loaded bass.

Mid and high frequency is K-402 with AXI2050. I was using BMS 4592-ND drivers until I received the new ones (only 14 weeks on backorder). The BMS drivers were very clean and sounded wonderful. I figured if the Celestion drivers were not an improvement, I could flip them for not much loss. To my ears the AXI2050s are better with a glorious midrange and good highs. Not needing to crossover to a tweeter gives a seamless sound.

Once I had the PEQs and delays figured out, I started with Chris Askew's Xilica settings for the AXI2050, the sound is very well integrated and holographic. I attended Axpona this year and listened to dozens of stupid expensive systems. What I have in my house for maybe $10,000 easily beats most of the $50,000 to $100,000 systems.

The only thing I still want is the dispersing lens Roy designed to improve the polars at high frequency. These are patented, and I wouldn't want to step on toes, but it sure would be nice.

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4 hours ago, grendel23 said:

I have a IB subwoofer system, 2 manifolds with 2 18" drivers in each. This sub is flat to 12Hz with very low distortion and prodigious output.

I have only seen IBs on a flat panel before. Can you share a picture of the manifolds?

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