TS Parameter changes during break-in

[Chris Roemer]

Thanks for all your hard work!

[DeZZar]

My pleasure. Happy to share.

[DeZZar]

7 Hours on the SB tweeter now. Because its in the office here with me I had them (two facing each other out of phase) in a small cooler bag, inside a larger cooler, stuffed with a blanket, then the cooler covered in two blankets and by the time I had that it just sounded like plumbing/the shower running in the house - so I could live with it for the day!



Interestingly here the Q values are all getting further away from spec. With the Dayton woofer the opposite trend is true - the values get closer to spec. Not sure what to make of it at this point - just reporting what I see.

Here is the updated frequency response. Because I made the mistake of not setting the voltage with the first measurement I have normalized these measurements to the same relative level @2K - so the changes you see in response are all relative to the level being aligned at 2K.


Definitely some smoothing apparent in the lower octaves now although some new peaks seem to be creeping in around 2.4K and that 13K region.

I've taken these measurements a few inches from the tweeter which upon reflection I'm not sure why I did that and I will probably try this again with another set of tweeters measuring right on the driver (near-er field? lol). Might not make much of a difference.

Distortion.....well I'm no expert in reading distortions. After the initial increase in distortion things have gotten better in some areas and stayed basically the same in others. My noise floor here where I live isn't great so I suspect it might be impacting these measurements more than it should.

What I notice is that although THD has improved, the 3rd, 4th, 5th harmonics have actually increased quite a lot. Taking 2K as an example. At 1 hour break in the 3rd order was reading 0.05%. After 7 hours it is now reading 0.149% and I notice it is similar for 4th, 5th etc. They've all increased a gotten a lot closer together but the THD at 2K has improved significantly going from 1.48 to 0.96.



Like I said I'm likely dealing with a bad noise floor and I don't think I've taken these measurements close enough so I might wrap this one up here and try again shortly with another set of new tweeters I have on hand.

I'm also about to run the process with an SB Satori MW16P and an SB23NBACS45 (aluminum 8" woofer). I'll report on these as soon as I can.

[DeZZar]

Thought I would add in here the Epique E180HE-44. I picked up a couple of these during a recent visit to the US for a future project. I thought I would test out how they measure. I haven't completed a full break in at this stage, and may not take these all the way, as agreement with factory is pretty good after just under an hour running @ 30hz.

No factory spec to compare with for wiring the voice coils for 4ohm, but 8ohm comparison looking very good.



Based on the measured results a single driver wired for 8ohms will achieve -3db @ 28hz in 30L.

Factory spec would achieve the same -3db @ 28Hz in 25L by comparison. I'll break these in a little more over the next couple of weeks and see where they land.

And boy can these little things move. I know they aren't the first small high excursion woofer around or even unique but I still love seeing such a small driver move this much!

[Colonel7]

So what are you thinking as far as design? Sub, 2- or 3-way, or something else? Very interested to see a non-sub design

[DeZZar]

Oh, sorry to disappoint. I was intending for a sub design - but a fairly different one. Going to be running with two of these in a tower design. A little way off as I've other projects to finish first.

[Steve Lee]

Ooooh!

I'll be watching this project closely - Thanks for doing this.