# Build a Quarter Pie Bass Horn (easy)



## claudej1 (Jan 6, 2008)

Here is a "topless photo" of the horn, LOL. Version 2.1
I spent a year, on and off in Hornresp, and finally built a pair of low profile bass horns that fit neatly into a corner. They are derived from the big MWM Klipsch Theater horn, cut in half, AND only use 60% of the floor space while only sacrificing the bottom 10 hz. They are designed to be bandpassed from 60-400 Hz. I'm currently using twin Danley DTS-10's for super sub duty down from the teens to 60 hz. I'm in bass heaven. They are super
easy to build with only 11 pieces of lumber from 4 sheets of 4x8, PL glue, and screws. the common internal dimension is 15.5 inches and they use a reconed EVM15L woofer available used on Ebay. They are basically a 5 foot long conical horn with a 90 turn radius, which gives them a 1/4 wave cutoff
in the 56 Hz. neighborhood. You can try other drivers if you wish, as I will provide the Hornresp data, but I have not found a driver that works as well as this one for the highs while maintaining the low end. If you take a Pumpkin Pie, and cut it into Quarters, it will look a lot like this horn, hence the name.


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## claudej1 (Jan 6, 2008)




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## claudej1 (Jan 6, 2008)

I used to use Peavey FH-1 bins, which are very much like a ruggedized/ugly version of a Klipsch LaScala or Belle Klipsch. This means that it's basically a 100 Hz. horn and I had to PEQ it with a 10 db boost at 61 hz. and knowck down the 140 Hz. peak common to LaScala/FH-1 types to get it to meet up with my DTS-10 subs with no FR gaps.

Obviously, that much EQ down low add more distrotion to everything coming out of there. I wanted to use the same woofers, but in a much better horn to pick the extra 45 Hz. or so ACOUSTICALLY with no EQ, just by using different "lumber." It is a success and sound wonderfully detailed and distortion free. For curve readers, I have included REW FR sweeps. Same driver, FH-1 in green, Quarter Pie Horn in RED. Not only is the bass much deeper, but the overall response is way SMOOTHER.


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## claudej1 (Jan 6, 2008)

So basically I used Four 1/4-20 T nuts/hex bolts to mount the woofer, and Eight of the same to bolt down the cover at this end (not shown, but it also has Banana Jacks for the wires). Also used peel and stick door seal from a roll available at Home Depot and filled the back of the woofer with spongy foam material, which worked well to dampen resonances in this rear chamber.


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## claudej1 (Jan 6, 2008)

2.1/7.1=R+L=QuarterPie Bass Horns/EVM15L driven by discrete gain B&K AV 1260 from Behringer DCX-2496 fed by Onkyo TXSR709 pre-out, Midrange=K402/K133, Tweeter=QSC PL-000446GP/B&C DE-250 each with single Capacitor HiPass driven by Onkyo 709 AVR Amp section. Twin Danley DTS-10 Super Spud Subs front and rear wall centers driven by 0.1 Pre-Out Y-connect to Adcom 555.
7.1=Heresy I Center, 4 KPT-200 Surrounds.
Oppo 83 SE with Sabre DACs for CD 2.1, HDMI out for 7.1 to Onkyo DSP's. Audyssey Multi EQ/XT room correction for ALL listening
Here's a photo of my "Wall of Sound" JVC HDTV 55" hides the "little" Danley DTS-10 from my sweet spot. LOL.


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## NBPk402 (Feb 21, 2012)

Hi Claude... Great write up! I can't wait to build mine. Mine will be a little different as you know. I will be using JBL 2360A horns with EV DHA-1, and the same woofers you are using. These will be my left and right channels with a Center channel consisting of a Faital LTH142 with the Faital HF 140 driver, and the same woofer as the left, and right channels. :T:T


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## claudej1 (Jan 6, 2008)

Suffice to say, it will be a huge improvement over LaScalas with vanilla horns and passive, constant K networks.


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## NBPk402 (Feb 21, 2012)

Any idea what the efficiency of these will be? I was looking at the drivers but they only list it with their horns.


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## claudej1 (Jan 6, 2008)

ellisr63 said:


> Any idea what the efficiency of these will be? I was looking at the drivers but they only list it with their horns.


Most bass horns from Klipsch come in at about 104 db/watt, more for others. With a typical 25 milliwatt input in my old FH-1 bins, I don't really care if these are 102 or 108. I wanted the bandwidth to fill up a gap without PEQ. So I honestly don't care. I still only need 20-100 times LESS power than "average" 88 db speakers out there and no one makes an amp small enough to ever clip.

It's like winning a free trip the Ritz in Paris for 2 weeks and wondering what your room number will be (IOW who cares, it's in the ballpark).

Not trying to demean your valid question, I simply don't know or care to measure it since I'm bi-amping, soon to be tri-amping with whatever voltage gain differential is required to get it all lined up.

In the mean time, I re listening to all my favorite recordings and discovering all kinds of subtle details


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## NBPk402 (Feb 21, 2012)

claudej1 said:


> Most bass horns from Klipsch come in at about 104 db/watt, more for others. With a typical 25 milliwatt input in my old FH-1 bins, I don't really care if these are 102 or 108. I wanted the bandwidth to fill up a gap without PEQ. So I honestly don't care.
> 
> It's like winning a free trip the Ritz in Paris for 2 weeks and wondering what your room number will be (IOW who cares, it's in the ballpark).
> 
> Not trying to demean your valid question, I simply don't know or care to measure it since I'm bi-amping, soon to be tri-amping with whatever voltage gain differential is required to get it all lined up.


No, I didn't mean on the bass horns... I meant on the JBL 2360A with the EV drivers... Just curious.:T


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## claudej1 (Jan 6, 2008)

Ah, got it. With the Q/dispersion of the JBL horns it's probably about 112. The DH1a drivers are 6 ohms and I remember them being 3.5 DB louder because of 6 ohms vs. 16 ohms (My JBL's were J (16 ohms) and not H (8 ohms).

Just looked up a 2446J and it's 111 db/watt at 1 meter for a 16 ohm version, midband (which yields the highest number. With the same voltage drive, you can add at least 3-4 db to that figure with the DH1A since it's 6 ohms. So it's up around 114-115 on the 2360A (midband). Now you know why I wanted you to get the EV's instead of JBL's. Cheaper, better, and more compatible with your chip amps, which I used to use with my DH1A's on the EV-940 equivalents of the JBL 2380 (small horn). I still have those horns, but the drivers are gone.


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## NBPk402 (Feb 21, 2012)

claudej1 said:


> Ah, got it. With the Q/dispersion of the JBL horns it's probably about 112. The DH1a drivers are 6 ohms and I remember them being 3.5 DB louder because of 6 ohms vs. 16 ohms (My JBL's were J (16 ohms) and not H (8 ohms).


WOW... I will be at reference level with 1 watt at my listening position! :T


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## NBPk402 (Feb 21, 2012)

I finally got 3 built! It wasn't bad at all... We had the wood ripped when we bought it and then just cut them down to size for assembly. I have to say they sound great! Here is a pic of them behind our screen wall (they are the big black rectangles on the stage right behind the 180" AT scope screen (JBL 2360a horns are above them).


As you can see it is literally wall to wall 1/4 pie bass bins with the AT screen being 15' wide. :T


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## claudej1 (Jan 6, 2008)

Very nice. Except I think you would have a slightly wider sound stage if you swapped the R and L. IOW, the core woofer section of R and L firing out instead of in.


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## NBPk402 (Feb 21, 2012)

claudej1 said:


> Very nice. Except I think you would have a slightly wider sound stage if you swapped the R and L. IOW, the core woofer section of R and L firing out instead of in.


I agree... I wanted to make them aim much more forward than the you did, hence them taking up almost 5' of the width for each one. It is hard to see in the pics but we tried to aim them as much as possible toward the MLP about 15' way... So they are not aimed like you did yours. The center is 100% aimed straight ahead too. :T If I ever get a chance I will try it with the woofers toward the center channel. :T


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## djxcell (Jul 19, 2014)

nice work


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