New Horns for Sound System.

[malsackj]

So What I have is a pair of used EV HP64 horns purchased on Ebay for 100. They are a fiberglass constructed, 2 inch throat. It is a CV horn with a 60 degree horizontal and 40 degree vertical pattern.

I have purchased the Coils and Capacitors for a simple 12 db high pass crossover for 300 watts. The Speakon cup and connecters are also assembled and ready to install like the ones used on Little EV. The crossover will be around 1.5k.

I plan to build boxes and to install outside the box mount for the DJ speaker stands. I did not want to use the cups going inside the cabnet because I can use fender washers to adjust the angle of the horn with some fender washers to help angle down and away from ceiling reflections.

The driver that I am looking at will cost 55 from parts express
IT is the Pyle PDB752.

http://www.parts-express.com/pe/showdet ... r=292-2550

 

[malsackj]

Here is a picture of the Horn.

This horn is similar to the one installed on the ANS gym project. That horn is a plastic body with a 1 inch throat. Using a 3.5 k crossover with a EV 2010 30 watt driver.

If anyone has questions and wants to ask I am opening this up to Flint for discussion.

 

[malsackj]

Here is the base speaker response that I have EV TL15-1 .

 

[malsackj]

There are several types of artifacts horns can generate which are often referred to as "ringing". One is the simple resonance of the horn itself, metal horns tend to ring at higher frequencies and for longer and plastic horns at lower frequencies for less long. Another is from the wavelength of the signal being less than 4x the diameter of the mouth which can cause that resonance in the horn from geometric space, for a 1" throat horn that starts at 13,536 Hz. Yet another is from the rectangular shape of the horn and the rate of flare.

I did my math wrong, the frequency where start for a 1" throat is actually 1/4 what I posted above. Actually the resonant ringing issues can start at 3,385Hz and happen at each harmonic to that frequency.

So for the two inch throat it would be around twice the number 6,770 hz, 13,540 hz, and 20,310.

the one inch will have more because it starts lower. 3385, 6770, 10155, 13540, 16925.

 

[malsackj]

Electro-Voice model HP64
constant-directivity horn.

Horizontal Beamwidth:
60° (+30°, -10°) (-6 dB 1.7 kHz to 20 kHz)

Vertical Beamwidth:
40° (+20°, -10°) (-6 dB, 1.8 kHz to 20 kHz)

Directivity Factor R(Q):
18.1 (average 1.6 kHz to 20 kHz)

Directivity Index Di:
12.6 dB (+0.9, -2.9 dB)
10 log R, (average 1.6 kHz to 20 kHz)

Lowest Recommended Crossover Frequency:
1000 Hz

Construction:
Polyester resin and glass-fiber laminate integrally
molded to a die-cast zinc throat section. This hybrid
construction assures a rigid driver mount, accurate,
loss-free throat-wave transmission and low total weight
compared to horns of similar size.

Mechanical Connection of Driver:
Bolt on; standard 2" diameter throat, 5" diameter
mounting flange and four clearance holes for 1/4" bolts
on a 4" diameter bolt circle. (See Figure 1).

Weight:
2.5 kg (4.5 lb)

 

[Flint]

There are several types of artifacts horns can generate which are often referred to as "ringing". One is the simple resonance of the horn itself, metal horns tend to ring at higher frequencies and for longer and plastic horns at lower frequencies for less long. Another is from the wavelength of the signal being less than 4x the diameter of the mouth which can cause that resonance in the horn from geometric space, for a 1" throat horn that starts at 13,536 Hz. Yet another is from the rectangular shape of the horn and the rate of flare.

I did my math wrong, the frequency where start for a 1" throat is actually 1/4 what I posted above. Actually the resonant ringing issues can start at 3,385Hz and happen at each harmonic to that frequency.

So for the two inch throat it would be around twice the number 6,770 hz, 13,540 hz, and 20,310.

the one inch will have more because it starts lower. 3385, 6770, 10155, 13540, 16925.

Half the number as it is a wavelength issue and a 2 inch throat is a longer wavelength. Also, hardcore beaming will occur where the wavelength is equal to the throat diameter.

 

[malsackj]

So basically that will mean that the 5 hotspots on the 1 inch plus 5 or 6 more added for harmonics.
When the RTA is done on the new horns with a screen capture posted we might be able to see some?

I was hoping others would be interested and have questions about this for you to work with.

 

[malsackj]

Here is a just published article on the drivers for the horns.

I think this is good information for people.

http://www.prosoundweb.com/article/grea ... drivers/av

 

[PaulyT]

Thanks, interesting read. I always wondered how compression drivers work, though I admit, I'm still not totally clear on it.

 

[DIYer]

Thanks, interesting read. I always wondered how compression drivers work, though I admit, I'm still not totally clear on it.

Still? Good thing soundhound isn't around to see your post. He would've used his belt on you. :violence-smack:

 

[malsackj]

There is another document on EV PA bible page on Drivers and horns.

http://www.electrovoice.com/downloads.p ... PA%20Bible

 

[PaulyT]

Thanks. My point of confusion was where exactly the moving parts are... Wikipedia has a pretty good diagram, to help dumbshits like me.

:text-link:

 

[malsackj]

The reason I was starting this thread is to help people learn more about the horns and how they work on speaker systems. I am glad that some people are benefiting from the notes attached. I was hoping for questions and participation from SoundHound and Flint. Seems that the readers do not have many questions.

The Mains (S15-3A) I have currently have the Phenolic resin. The ones I am building will be Titanium, and the ones I cannot afford are the beryllium (300 plus).

 

[jomari]

i love my horns.

now i know why.

thank you for sharing buddy. i wish i could understand more about it, but im trying, by jessuz mary and joseph i am trying...

thank you again. hope you dont mind me taggin along on your build.

one thing i wish i could do is build things. i bet my first speaker will have a 'slant' look on a bookshelf.

 

[malsackj]

So I have a question? These new drivers have a phase plug to correct some issues on the throat.

My question is are there new designs for the base module to incorporate this phase plug into say the Altec A7 base section?? Is there a reason we have not seen this??

 

[malsackj]

So I have mounted the Pyle PDB752 to the horn and this weekend I will have the cash to buy the Cabnets. Having the plywood cut and assembled by a neighbor.

 

[PaulyT]

Wow, that's a beast!

 

[Flint]

All horn drivers have phase plugs. The purpose of the phaseplug is to facilitate extremely high compression just in front of the diaphragm with multiple pathways from the diaphragm to the throat which are exactly the same distance to align the pressure waves perfectly where they meet in the throat.

Community Speakers made cabinet horns for mid and kidbass cone drivers with large phaseplugs intended to increase compression and assure some amount of phase accuracy from the cone to the horn mouth. I don't believe community still makes products with that tech anymore.

 

[malsackj]

Ok so I pink noise test these outside facing the sky at 125 watts with the mic at 4 feet above the horns. This will take some work to get the drop from 10 k to 18k back up to equal but this is normal for most Constant Directivity Horns.

 

[malsackj]

I used the Rane AC22 crossover set for 1.5k and had the high into my Carvin Fet450 with max power at 125 watts on one channel into the driver and horn. This horn will take 800 watts peak.