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Old 4th July 2014, 02:33 PM   #1
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Default A question on compression drivers ... am i in the right place ?

Hi, after years spent in admiration of compression drivers i could not resist and i bouth a pair ... these ones

Pyle 800w 3" Titanium Horn DJ Cabinet Compression Driver 8 Ohm Bolt On Tweeter | eBay

i guess is this one ...

PylePro - PDB752-DJ Equipment-DJ Tweeters and Horns

The reason why i bought them is the impressive freq response ... it can be used from around 500 Hz all the way up to 15kHz ... and for me could be enough in the high
Being completely ignorant i wonder which kind of horn could be used on this driver
I would like a shallow one possibly ... and with a price in line with the driver, that is cheap
For the rest of the range (i.e. from 500 Hz down) i will use a 2nd PA speakers
Thank you very much for any suggestion
Kind regards, gino

Last edited by ginetto61; 4th July 2014 at 02:36 PM.
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Old 4th July 2014, 02:44 PM   #2
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It's a 2" exit driver so look for a 2" bolt on horn with a 4" bolt pattern.
The frequency response is listed as 1k and up but I don't see much in the way of specs. If you can find the resonant frequency, double it as your starting point for the XO, minimum 2nd order.
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Old 4th July 2014, 03:05 PM   #3
AndrewT is offline AndrewT  Scotland
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the hole for the music to exit looks like it is drilled as parallel.
Does that mean the horn must have a 0 (zero) degrees included angle throat to match with the driver?
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Old 4th July 2014, 06:42 PM   #4
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[QUOTE]
Quote:
Originally Posted by Cal Weldon View Post
It's a 2" exit driver so look for a 2" bolt on horn with a 4" bolt pattern. The frequency response is listed as 1k and up but I don't see much in the way of specs.
Hi and thank you very much indeed for the very valuable reply.
First let me explain my "insane" project
Looking at the freq response in the datasheet attached i see the 500 and the 15kHz at the same level ... very impressive
Unfortunately there are no TS parameters and the indication of the horn used to get the response is missing
As i am getting old i think that 15k will be more than enough ... i could not listen above i am afrain
this would be the high section of my retirement speakers
The ears get stiff with the age and some more SPL is required
Joke aside i have become lately a lover of high efficiency speakers
Why go with hundreds of watts when there are driver so mighty powerful ?
And i would bet that the distortion at normal SPL out of this driver will be exceptionally low ... maybe i am wrong. What do you think ?

Quote:
If you can find the resonant frequency, double it as your starting point for the XO, minimum 2nd order
Thank you very much for the very precious advice
I could try sending an email to the support service
But a 75mm diaphragm should have no problems to give a good 500 Hz
And it should be also quite robust i guess
I have to find a programm to calculare the filter also
For the range 500 to 50 i would look for something PA ... that could give me an overall sensitivity of around 95 dB
I am expecting a great sound indeed even with very little power

Regarding the horn ... could you recommend me any specific brand/model ?
Thanks a lot again.
Kind regards, gino

P.S. i would like to add only a thing i have read on a magazine regarding a pubblic demo of the JBL Everest
They are practically a 3 ways with a mid with a 4" diaphragm ... even bigger that this one
Just to test its freq response they put a blanket on the tweeter and nobody felt that something in the highs was missing
I am looking only for the 15kHz .. no more
But also for a midrange with very very low distortion
Attached Files
File Type: pdf PDB752.pdf (145.3 KB, 15 views)

Last edited by ginetto61; 4th July 2014 at 06:48 PM.
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Old 4th July 2014, 09:06 PM   #5
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According to the spec sheet this is a 1.4" exit driver which means it likely has an 800-1khz minimum crossover frequency. You could use a 2" exit horn with a 1.4" adapter but there are also 1.4" exit horns now too like this one.. Pyle PH916 1.4" Bolt-on Constant Directivity Horn
That horn has a minimum crossover freq of 1khz so that's what you need to use, but given the drivers sensitivity you could use a pair of 12" drivers with each one to get a very high output system.
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Old 4th July 2014, 09:08 PM   #6
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Are you using this for home listening or PA use?

You can build ur own horn, btw.
The most obvious and simple way to start is a conic horn.

IF the driver throat has any length (these look to the unaided eye as only the thickness of the front pole piece and the depth of the magnet?) to the expansion that is simply a parallel (cylindrical) wall section, then they are likely intended for "Oblate Spheroid" type "waveguides". Although this is not certain, and I am speculating here.

regardless, it is a good idea to continue the expansion of the driver's internal expansion and not deviate quickly, causing a discontinuity.

But beyond that, you could use any horn you wanted that mated up with the exit hole. The depth of the horn will be dictated entirely by the expansion type and the lowest frequency required, which will dictate the mouth size, and so due to geometry, the length.

The shortest horn expansion seems to be the "oblate spheroid" or the Geddes type waveguide (there are at least cosmetic similarities).

I'd not try to get into horns and aim for short depths in general.

To cover down to 500Hz, expect to need to have a horn that has a geometry designed to go a bit lower in most cases...

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Old 4th July 2014, 10:07 PM   #7
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Quote:
Originally Posted by conanski View Post
According to the spec sheet this is a 1.4" exit driver
That would make sense for a 3" diaphragm. Where did you find the spec sheet?
EDIT: Never mind, I found it.
Gino, there are lot's of 1.4" horns so find what suits your needs. If you have to you can buy a screw on adapter that bolts to your drivers so you're not limited by what horn.
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Old 5th July 2014, 05:49 AM   #8
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[QUOTE]
Quote:
Originally Posted by conanski View Post
According to the spec sheet this is a 1.4" exit driver which means it likely has an 800-1khz minimum crossover frequency.
Hi thank you very much indeed and this is very unfortunate ...
I was sure that this driver could go lower and it was my main aim for selecting a 75 mm diaphragm ... i want the 500 Hz absolutely
To this goal i should look for a driver with a 2" exit horn i understand ?
Are you aware of some drivers also on the cheap side but able to give also the 500 Hz ?
I am sure that 500 to 15kHz with a single driver is possible and this is my aim
This is a fixed requirement
Any suggestion in this direction would be very much appreciated

Quote:
You could use a 2" exit horn with a 1.4" adapter but there are also 1.4" exit horns now too like this one.. Pyle PH916 1.4" Bolt-on Constant Directivity Horn
That horn has a minimum crossover freq of 1khz so that's what you need to use, but given the drivers sensitivity you could use a pair of 12" drivers with each one to get a very high output system
Please let me elaborate a little
I will use it in a home context of course very attenuated
My main goal more of SPL is extremely low distortion
My understanding is that the distortion from these drivers used at very low level (like 90 dB at 2 meters) is practically non existing
And this is what i want ... no distortion to speak of.
I have come to the conclusion that this is the heaven of sound ... no distortion at all.
Any suggestion for such a driver would be very much appreciated.
Just reasonably priced ...
Thanks and kind regards, gino
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Old 5th July 2014, 06:05 AM   #9
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Quote:
Originally Posted by bear View Post
Are you using this for home listening or PA use?
Hi and i am going to use it for home listening for a zero distortion project.
My idea is that a driver of this kind used at very low level has no distortion at all ... i mean huge dynamic with the transparency of an electrostatic driver
The ultimate sound experience ... something completely out of reach for a conventional speaker ...

Quote:
You can build ur own horn, btw.
The most obvious and simple way to start is a conic horn.
IF the driver throat has any length (these look to the unaided eye as only the thickness of the front pole piece and the depth of the magnet?) to the expansion that is simply a parallel (cylindrical) wall section, then they are likely intended for "Oblate Spheroid" type "waveguides".
Although this is not certain, and I am speculating here.
regardless, it is a good idea to continue the expansion of the driver's internal expansion and not deviate quickly, causing a discontinuity.
But beyond that, you could use any horn you wanted that mated up with the exit hole.
The depth of the horn will be dictated entirely by the expansion type and the lowest frequency required, which will dictate the mouth size, and so due to geometry, the length.
The shortest horn expansion seems to be the "oblate spheroid" or the Geddes type waveguide (there are at least cosmetic similarities).
I'd not try to get into horns and aim for short depths in general.
To cover down to 500Hz, expect to need to have a horn that has a geometry designed to go a bit lower in most cases... _-_-
Thank you very much indeed for the very valuable advice
If i understand well you mean that to get the 500 Hz i would need necessarily a big and deep horn ? that i do not like ... i would like to get one reasonably small ....
I think i should give up with the 500 Hz idea in the case.
I do not want something very intrusive ...
Anyway i wonder what kind of driver could give me this blessed 500 Hz
I do not like the woofer to cope with this frequencies ...
Thanks a lot and kind regards, gino
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Old 5th July 2014, 06:16 AM   #10
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Quote:
Originally Posted by Cal Weldon View Post
That would make sense for a 3" diaphragm. Where did you find the spec sheet?
EDIT: Never mind, I found it.
Gino, there are lot's of 1.4" horns so find what suits your needs.
If you have to you can buy a screw on adapter that bolts to your drivers so you're not limited by what horn.
Hi and thanks very much again
But if it is true that this bloody driver cannot give the 500Hz i wonder how they have got that freq response ... if only these nice people told me which kind of horn they have used ....
My dream is 500 to 15k with the same driver ... without having to buy a 4" JBL totl driver ... that i know can do this ... amazing performance
The one on the JBL everest for instance can do this quite easily
A blanket on the tweeter was not impacting substantially the overall performance at a pubblic demo of the speakers
I have the feeling that having the 500 to 1000 range reproduce by the midtweeter should give a much better sound ... less distortion i mean than in the case of the same window reproduced by the woofer
I have no measurements but i would think so
Thanks again and kindest regards, gino
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