Big Time Full Range

[weltersys]

This is is a full range speaker I'd like to have heard.
Makes my parent's Magnavox console look like a toy.

 

[Inductor]

I guess it's not raining. A cross between 'Saturday Night Fever'... and '(Jazz) On a Summer's Day'?! 😀
http://en.wikipedia.org/wiki/Idora_Park

 

[Jsixis]

29 square miles, wow

 

[weltersys]

29 square miles, wow

The big horn probably had sensitivity of around 115 dB at one watt one meter, using a "receiver" (driver) like the 6 watt Western Electric 555 it could hit perhaps 123 dB.

Compared to radios or Victrolas that would hardly hit 80 dB, that would have seemed incredibly loud.

At 8192 meters (5.04 miles) the level would have reduced by at least 72 dB (-6 dB per doubling of distance), to 51 dB, audible in the days when there were few automobiles.

Funny to think that an 8" full range could achieve that level now in a 1 cubic foot box.

 

[freddi]

that was a beauty - - I love my Orthophonic Victrola tho

 

[Overkill Audio]

Full range...123dB...1 cubic foot....???

Hi Welterslys

I must have missed that particular full range driver you are talking about...
123 dB in 1 cubic foot??? At what distortion?
Please do post the link...!


Full range being 20Hz to 20 KHz?
Or do you mean full range as defined by Lowther, Fostex, etc ie midrange only...Please add subs and tweeters if you like music.


Cheers
Derek.

 

[weltersys]

Full range being 20Hz to 20 KHz?
Or do you mean full range as defined by Lowther, Fostex, etc ie midrange only...Please add subs and tweeters if you like music.

Derek,

Not 20Hz to 20 KHz, more like 125 Hz to 5kHz like the big horn, but it would probably take two 6" or 8" PA type "full range" to hit 123 dB.

 

[Overkill Audio]

Midrange 123dB...

Hi Weltersys,

Now I am with you...PHL Audio do some lovely 6inch, 8 inch and 10 inch midrange units that cover 150Hz to 4Khz, subject to directivity Vs. size of unit.
They are all around 97dB to 100dB sensitivity for 1 watt at 1 meter.
In a flat baffle they are good for 115dB to 119dB.
Used in horns they will reach around 120dB to 123dB.
I have attached a pic of a solid wood ( MDF block turned on a Lathe) I used for both the Manger driver and a range of 8 inch cone drivers the horn added about 4dB or 5dB of sensitivity, but it was big, ugly, 25Kg and cost waaaay more than simply adding another driver.

Personally I would rather use 2 or more drivers ( I love line arrays!) to gain headroom / efficiency rather than use horns.
A matching line array of Beyma TPL drivers would be a party... 6 by 8 inch PHL with 4 TPL will give around 106dB for 1 watt at 1 meter all the way from 150Hz to 20KHz with ultra-low distortion...Approx. 70% LOWER distortion than the single drivers!
The power handling would be huge....You could sustain 133dB all night...Rock concert stuff with studio grade quality...
The bass requires a bit of effort to match the mids and top, but given a DEQX crossover, space, enough Hypex Ncore and a stack of Precision Devices drivers you could match the bass / mid and top without losing any sensitivity...
Oh yes about £20,000 for parts as well...One day!!!

Cheers
Derek.

 

[Greg B]

Was that actually the first use of an electrified PA system? Very cool horn. It must have seemed mindblowing at the time. It's amazing how many amusement parks have come and gone. There's nothing that cool in Oakland now...

 

[weltersys]

Was that actually the first use of an electrified PA system?

The 1922 Magnavox horn was quite an achievement, but electronic amplification for PA use had been demonstrated since around 1908.

In over 100 years of transducer and amplification design the changes have been small incremental steps, many of which have been sideways...