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RE: tomservo - question on your small studio monitor

Posted by tomservo (M) on April 10, 2024 at 05:48:52

In Reply to: tomservo - question on your small studio monitor posted by Edp on April 8, 2024 at 15:08:29:

Hi
Well you have the way back machine on haha

The patents covers this concept;

An exponential horn has a fixed expansion rate and that governs where the "high pass" for the acoustic impedance transformation takes place. For example a 30Hz horn can only double it's cross sectional area every 2 feet but at 60Hz, it's 1 foot and so on up in frequency...

A conical horn has an expansion rate that changes from throat to mouth and while it has constant directivity (good when you have an audience vs a seat) , it also means the HF driver at the apex is poorly coupled as the frequency falls, the expansion is too rapid at the apex.

The patent for the Unity horn (my first try from back when you remember) covered the idea of coupling drivers appropriate for horn loading where the expansion rate was also appropriate.


This also meant that if drivers interacted, the sources must be 1/4 wavelength or less apart to couple into the horn seamlessly. This allowed the radiation to appear to be a single driver but still had all the phase response of the combined crossovers like a traditional mullti-way loudspeaker.

The later Synergy horns (about 20 years ago now) i found a way to have a high order passive crossover slopes without the phase shift /all pass phase response the named slopes cause. That way they radiate like a single source in time and space with the directivity of the CD horn. This is possible because the drivers are coupled together within the horn and the physical offset is incorporated to counteract the filter delay (something like a physical FIR filter perhaps)



The picture you linked is a typical configuration as a DIY project, the MEH name being a sub for the Synergy horn / Unity horn objective principals as the patent wasn't applied for in Australia.

One of the configurations in the patent is a way to use a coaxial driver that has a compression driver for the hf. This allows the cone output to combine with the HF again where the dimensions are less than 1/4 wl. That is what is in some of the smaller synergy horns like the small studio monitors in the video.
My interest is home audio, i like making big stuff for stadiums and large hifi out doors like for the mouse house but I like to listen sitting on the couch playing bass.


All along i have been making small speakers too at work for the fancy stadium suites and a couple customers started using them in studio's and then I made some big ones for larger rooms and then the ones you saw.

Those have a coax cone driver with a normal HF compression driver where the cone output is passed into the horn expansion where the dimensions are less than 1/4 wl so the combine coherently into a full range driver and the LF driver is close enough to be less than 1/4 wl apart.
They like them in the studio because they say they can hear everything, important in the creative / mix and mastering process..

The thing i love about these simple acoustic sources full range horns is they often disappear in the phantom image to where your not aware of them as sources, with eyes closed it's harder to tell how far away they are as single sources, they don't radiate many spatial clues that normally would become part of the stereo image.

My hope is the that the people with home studio's will see these recordings and embrace these for the same reasons, those musicians are the future of our program material.

Here are a couple songs from Albums that were recorded using them.

https://www.youtube.com/watch?v=d95WgaXjiBE&list=RDGMEMQ1dJ7wXfLlqCjwV0xfSNbA&start_radio=1&rv=auTP6NxfikA

https://www.youtube.com/watch?v=auTP6NxfikA&list=RDGMEMQ1dJ7wXfLlqCjwV0xfSNbA&index=3





I thought this one was cool as they made the video while recording the album and after i found they were very happy with the result. People sometimes wonder how recordings are made what it looks like and what a producer does.


https://www.youtube.com/watch?v=a1q25yLgRSc

I got to see these folks live, as good live as any band i have heard. Carl the guitar player gave me a big hug after they played.

https://www.youtube.com/watch?v=UzwKOI5Rcnw


As we are not a sales and marketing company, I think these are being sold to that market via a company called Sweetwater.

Hope that helps

Tom

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Kimber Kable

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