I theorize: 'Synchaeta'....a Minimus 7 revamp...

[Mark65]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

It's not often I have to use a dictionary on 2 of the first 4 words of a sentence.

My thoughts exactly.:D

Looks like a nifty little speaker, though.


Mark

[fdieck]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

Now I know... Understand the part about limited space. I updated the crossover on a pair of Pioneer B22s and it was a tight fit for two 100V film caps.

[isaeagle4031]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

I think I am probably missing something, but why not take the tweeter down to at least 3 KHz? It looks like that tweeter looks like it could do it with no sweat.

Ben and I talked about this when he started formulating the plan. Part of it is the crossover size. It's pretty small area to fit it into. And really look at that phase! That is just where these 2 meet up really well.

[fdieck]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

I think I am probably missing something, but why not take the tweeter down to at least 3 KHz? It looks like that tweeter looks like it could do it with no sweat.

[Paul Carmody]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

Synchaeta is a rotifer, ...
Wolf

It's not often I have to use a dictionary on 2 of the first 4 words of a sentence.

[Wolf]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

You see how close to the RS they match? That's just unbelievable!!!

Oh- on test tones, the PRV actually played well up to 15k. The breakup was not really objectionable either, so my methods should work appropriately.

This will happen...
Wolf

[isaeagle4031]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

Can't wait man!

[kevinr]

Re: I theorize: 'Synchaeta'....a Minimus 7 revamp...

thanks ,
subscribed

[Wolf]

I'm awaiting the pictures from Bill to arrive taken from InDIYana before I do my official walkaround, so I felt I should do something else while I wait for them...

Synchaeta is a rotifer, prevalent in both salt and fresh water, and capable of living very easily all over the world. Being they are small in size, the cabinet is a 'synch' to build, and it has prevalent applications for all sorts of sound systems, I dubbed the name appropriate. More on the cabs later.... (yes- I'm building these!)

This has been brewing for awhile now, to revamp an old set of speakers many people have. I'm going to start off by drivers used, the PRV 4MR60-4, and the Dayton ND25FA-4, so this is in fact a 4 ohm system design. The specs have a high Qts on the PRV, and they were similar to the older Radio Shack 40-1030 4" that Matt and I swapped in for better results than the stock units.

40-1030:



PRV:



Not only was it that it was close, but it was also higher sensitivity. The breakup wouldn't be hard to fix, so I modeled the stock specs and came up with this as a best compromise:

Preliminary box:



Well- I measured the PRV's today, and they measured quite a bit differently than they were spec'd:




So- I have to remodel the box yet, but I'm confident it'll match the 40-1030 closer than originally intended. I'll update this in the future...

On with the preliminary xover...






It came out really nice and easy at 7 parts. I recommend 5W resistors where possible, and even rod-core or steel-core inductors to make the networks fit in the box. I wound a 1.2mH coil from 18AWG around a steel spacer from the hardware store for mine, and I wound the tweeter coil around the tweeter cap to save space in layout- pictures to come later. The 15 ohm 5W resistor will be soldered to the tweeter itself, and sits perfectly between it's terminals to do so. I'll likely solder the RC across the woofer's terminals for the same space concern reasons. Came out an asymmetric BW2/BW3 at 4.2k- not bad!

More to come, thanks for looking!
Wolf