Snowy Day experiment (Up-firing, wall coupled coaxial)

[outlookrt]

With it being an grey, snowy and windy day and me being a little frustrated/bored with my DIY sealed speakers using Seas coaxial t18 drivers I thought I would try something a bit different. I ended up giving them a go up-firing, on the ground and as near to the front wall as possible. Tried some scrap wood to help smooth the response. Sort of Carlsson/Sonab inspired approach I suppose? XO is only 2 parts. A coil on the woofer I had and a Cap on the tweeter.

It's all a bit of stupid fun, but the effect is somewhat satisfying. Response is workable, and with some very quick measurements and rough EQ to calm too much energy in the 125-200hz range (boundary related?) and the very top end above 10khz (tweeter/measurement related) it's actually pretty decent. Both could probably be fixed with proper cabinet/positioning/Xo. quick averaged L+R measurements from LP (mic vertical)

Subjectively it sounds... interesting? Imaging is unsurprisingly diffused. Both in horizontal and vertical space. With some sounds seeming to come from up-high and others low and close to the speakers. A sorta odd effect actually. Reverb effects seem maybe more satisfying than usual giving even modern pop recordings the feeling of being in a very far/high seat in a hall. Maybe it would be a little more focused if the drivers work tilted more towards the LP vs totally upwardly firing. Or not using a coaxial and having the tweeter on the board tilted forward would work. Or maybe it's just a massive waste of time

Anyone else ever tried anything similar? I suppose it's sort of a omni effect.
Hoping others have been able to have a bit of DIY tinker time this weekend!

 

[Head_Unit]

IIRC Allison Acoustics or *somebody* had a bit of something like that. Tweeter up top near the wall. Maybe the Allisons had the woofer on top? To get closer to the wall due to wall bass boost.

Your measurements look surprisingly good, almost shockingly good considering the application.

The raw SEAS coax measurements have always looked really rough, turned me off, but how are you finding them?

 

[trl]

Would be nice to compare both measurements, before vs, after, although tweeter response is totally dependant of the reflexive surface, so quite tricky in getting the trebles sound right by doing up-firing...I'd say.

 

[outlookrt]

Getting back to this thread after life stuff had me distracted. I recently moved house so can't directly address those measurements/design any more but am going to try and play more with these DIY speakers.

The seas coaxial does measure rough in the highs due to the coaxial arrangement although in my experience they sound pretty good and the resonances in the highs are not an issue when listening in-room, especially if a bit off-axis as they smooth out.
That said the rough measurements does make it a bit tricky to dial-in the amount of highs in a DIY Crossover design or EQ. No matter how close I got in the measurements/sim I found I had to adjust by ear even if it didn't as flat as it could have been. But this is my first DIY design/project so maybe thats just down to experience.

The more I worked with the driver the more I think my preferred use of it would be in a small speaker low to the ground with the speaker aiming upwards + on an angle towards LP. With the right tuned vent it should reach pretty low close to floor/front wall boundary , and the slight off-axis listening angle would smooth out the FR, and the coaxial arrangement would provide decent dispersion of sound into the room. This could be build in the style of a Sonab/Larsen/Shahinian speaker. This sort of design would suit my new living room space well so hopefully I can make the type to try it out.