Still stuck for choice over Dayton rs100 or Fountek fr88ex

[jamikkim]

I have had this design all ready to go except for time/money, but now I'm wondering if the Fountek fr88ex has a noticeable difference in the midrange? The Dayton does have a spike and rising 3rd order HD at about 2kHz (which is where it begins to roll off in the crossover) Will this spike be very noticeable?

rs 100 TL Design, now a year old :o : http://techtalk.parts-express.com/sh...=rs100+tapered


I probably should stick with the TL, since some people did help me with it...they would be interested to see the result.

What the design I end up building is up against is this: http://images.kenwood.eu/files/image...inal/AX-7n.jpg

Obviously comparing the bass response is not very fair, but I'm looking for better mid/treble. The Ax-7 speakers are fairly simple in design, but they sound OK to my ears and compared to other commercial offerings.

I'll post some pics tomorrow or in a few days time...

[edlafontaine]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

Your answer may be found here:

http://zaphaudio.com/smalltest/

Zaph begins with:

This is without a doubt the highest performing 3" I've come across, at least on...

also read augerpro:

http://www.htguide.com/forum/showpos...3&postcount=10

[MSaturn]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

The FR89 (as opposed to the 88) will come closer to the bass performance of the RS125, as well.

[jamikkim]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

Some pics of the AX-7's 12cm woofer found here:
http://www.newgrounds.com/dump/draw/...955e72d30a.jpg

http://www.newgrounds.com/dump/draw/...068428a4aa.jpg

3D visualisation of what the Dayton/Vifa TL will look like:

http://www.newgrounds.com/dump/draw/...5fd1ac8764.png

I think I will stay with the Dayton until I can get back up to scratch with the PCD, etc. skills I had a year ago, then I may try the fr89 with a tweeter, maybe the SB dimple dome that Zaph tested. I just know I would feel bad for not building after using others' time and mine...

If you have any critique on the design, feel free to post it.

[Wolf]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

I would tweak your L-pad a bit. You're dipping low above 10k in impedance level, and you still have that rise that could be painful. That 2.5 ohm resistor you have there is a very small value that can cause your impedance issue.

bump up the series R, and use a zobel for the parallel leg. Say, 4-5 ohms in series, and a 2.7uF and 4 ohm zobel to start off with. That 33uF cap is also quite large and costly for the tweeter circuit. I'm sure you can reduce it's value.

Make sure that 15uF cap in the woofer has some sort of resistor after it, or place one post-sim of 4 ohms in series with the tank-cap acrossed the coil. You may be able to combine the cap and the zobel to reduce your parts count.

Later,
Wolf

[jamikkim]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

I have tweaked the L-Pad and reduced some of the large cap values, but I can't seem to reduce the >10kHz without creating a dip in the treble. 3dB isn't that noticeable up there is it?

I also found out that if I buy the inductors from my local store, they will cost $40! I wonder if PE will still be cheaper after shipping?

Anyway, I have attached the PCD files if anyone wants to have a look, just rename the .txt to .zip

[Pete Schumacher]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

I have tweaked the L-Pad and reduced some of the large cap values, but I can't seem to reduce the >10kHz without creating a dip in the treble. 3dB isn't that noticeable up there is it?

I also found out that if I buy the inductors from my local store, they will cost $40! I wonder if PE will still be cheaper after shipping?

Anyway, I have attached the PCD files if anyone wants to have a look, just rename the .txt to .zip

OK, I played around a little.

I dropped the zobel on the woofer.

Set the main inductor to 1mH, the notch capacitor to .15uF, and the shunt cap to 15uF.

The tweeter, I have the C9 at 2.7uF, L9 at .15mH - .2 Ohm, C10 at 20uF.

To tame the top end a bit, I have L8 set to .05mH. That's the inductor in series with the first L-pad resistor of the tweeter, R10, which I have set at 4.7 Ohm. The shunt L-pad resistor, R16, is 6.8 Ohm.

Try those values out and see what you think. ;)

[jamikkim]

Re: Still stuck for choice over Dayton rs100 or Fountek fr88ex

Ok, thank you, I think I might stay with what you worked out, since it is fairly low in components and is about as flat as it will get, besides, other variations will probably have more of an effect on the response...

I'd better ask DArcher to get some rs100's while they are on special :D