InDIYana 2021; Loudspeaker DIY event...

[Meredith Cargill]

Using OmniMic. The unsmoothed response looks pretty ragged, especially above 2kHz. But with 1/3-octave smoothing it was flat +/-3dB from 62Hz to 16kHz. The driver has a response peak 3kHz-4kHz, and the dome-deflector-waveguide hornloaded the diaphragm to produce a response peak around 1100Hz. So I used two contour filters to pull those two bands down to get the response that flat.

There was more variation in the horizontal dispersion than I expected. Below 2kHz, the response did not vary more than 1.5dB for all 360 degrees around (1/12-octave smoothing). Above 2kHz, the variation was as much as 4dB. These variations are probably due to my not making the baffle and waveguide perfectly symmetrical.

The intention was also to have as uniform response in the vertical as possible. Up to 5kHz, the response from 20 degrees below horizontal to 80 degrees above horizontal does not differ by more than +/-6dB from horizontal (seated ear level). At 30-50 degrees above horizontal (probable ceiling-bounce angle), response below 6.5kHz is within 4dB of the horizontal response.

Because it generates so much high-frequency reflected sound in a room, it measured unusually flat using the RTA at the InDIYana venue, compared to all the conventional designs, which had tweeters with limited directivity.

 

[tomtoo]

Using OmniMic. The unsmoothed response looks pretty ragged, especially above 2kHz. But with 1/3-octave smoothing it was flat +/-3dB from 62Hz to 16kHz. The driver has a response peak 3kHz-4kHz, and the dome-deflector-waveguide hornloaded the diaphragm to produce a response peak around 1100Hz. So I used two contour filters to pull those two bands down to get the response that flat.

There was more variation in the horizontal dispersion than I expected. Below 2kHz, the response did not vary more than 1.5dB for all 360 degrees around (1/12-octave smoothing). Above 2kHz, the variation was as much as 4dB. These variations are probably due to my not making the baffle and waveguide perfectly symmetrical.

The intention was also to have as uniform response in the vertical as possible. Up to 5kHz, the response from 20 degrees below horizontal to 80 degrees above horizontal does not differ by more than +/-6dB from horizontal (seated ear level). At 30-50 degrees above horizontal (probable ceiling-bounce angle), response below 6.5kHz is within 4dB of the horizontal response.

Because it generates so much high-frequency reflected sound in a room, it measured unusually flat using the RTA at the InDIYana venue, compared to all the conventional designs, which had tweeters with limited directivity.

Wish i could listen to them. What was your intention, when you designed them? Do you think the design would work, outdoors in a garden? Sry for that many questions, iam a curious person.

 

[Meredith Cargill]

My only intention was to show it at contest, and experiment. Yes, I thought of a garden party, or party in a large indoor space with people moving and standing all around at unpredictable places (on a balcony, for instance). For out of doors in a level garden or lawn, wide vertical dispersion is not needed; limited vertical directivity would make more sense.

Set it next to a mirror ball lawn ornament and see if they make babies. Leave it out in the rain and it becomes a birdbath. Build a whole chess set and have dueling multichannel surround-and-capture sound. Lots of uses.

 

[Deleted member 12642]

I'm sad I missed this, it's actually near-ish to me. Hopefully they do something next year.

 

[Wolf]

In case you missed it, this event has been going annually since 2007. I've been hosting since 2009, and due to Covid, 2020 is the only year without one since. It is typically held in Ft. Wayne.
https://sites.google.com/site/indiyanaevent/

Thanks to Midwest Audio Club for archiving the various DIY events, and of course to Bill for being an excellent photographer. You can see various photos of past events at the link below.
https://midwestaudio.club/

 

[tomtoo]

My only intention was to show it at contest, and experiment. Yes, I thought of a garden party, or party in a large indoor space with people moving and standing all around at unpredictable places (on a balcony, for instance). For out of doors in a level garden or lawn, wide vertical dispersion is not needed; limited vertical directivity would make more sense.

Set it next to a mirror ball lawn ornament and see if they make babies. Leave it out in the rain and it becomes a birdbath. Build a whole chess set and have dueling multichannel surround-and-capture sound. Lots of uses.

"..Leave it out in the rain and it becomes a birdbath.."

Ok i see(imagine). The driver itself would be the water collector?