Am I on the right track? Bookshelf speaker Fountek FW146 / Dayton DC28F

[rpb]

Here's a 6th order. I changed values to simplify it, so, it's a little different than the one I already posted.

[crossbound]

rpb that is pretty impressive. I'm trying to keep my XO just a little more simple. It's cool to see how much fine tuning you can do. Wow..

[crossbound]

Great I was just about to upload what I thought was my final response curve and crossover, and then I looked at the impedance graph for the tweeter and I realized it was empty.. Something was wrong with the impedance file and I had to revert back to the original one. Of course that messed everything up again.. I'll get there eventually.

[WernerM]

If you haven't actually purchased the drivers, I would like to suggest looking for a little better tweeter. For not much more money this one looks viable...

http://www.parts-express.com/dayton-audio-nd28f-6-1-1-8-soft-dome-neodymium-tweeter--275-040

and with a smaller frame would be easier to mount, plus a better CTC spacing. Just a suggestion, as it may be smoother overall. That peak at 4k may be due to diffraction and trying a tweeter like this which could be offset may help smooth that out.

There are plenty of other options, the BC25 is a nice tweeter also, but just looking at manufacturer specs I believe the one I suggested is better. Lower Fs, smoother off axis with less dramatic drop offs also.

This is just my humble opinion.

[crossbound]

If you haven't actually purchased the drivers, I would like to suggest looking for a little better tweeter. For not much more money this one looks viable...

http://www.parts-express.com/dayton-...eeter--275-040

and with a smaller frame would be easier to mount, plus a better CTC spacing. Just a suggestion, as it may be smoother overall. That peak at 4k may be due to diffraction and trying a tweeter like this which could be offset may help smooth that out.

There are plenty of other options, the BC25 is a nice tweeter also, but just looking at manufacturer specs I believe the one I suggested is better. Lower Fs, smoother off axis with less dramatic drop offs also.

This is just my humble opinion.

Funny you would mention that WernerM, I was actually thinking about looking at other tweeters.. I was trying for quite some time to see if there was a way to squash down that peak at 4k.

[crossbound]

Oh my goodness.. I decided to try a different tweeter (Peerless BC25SG15-04) since I was struggling so much. Took me all but a half an hour to get a good looking response curve done, and reduced XOver parts cost by about $20. wow..
Looks a whole lot better and my confidence is restored.
Unless somebody has any other suggestions or concerns about what I came up with, I think this thread has been beaten to death long enough. Thanks to everyone that chimed in and helped me along the way. It's greatly appreciated and I learned a ton!

[Wolf]

That tweeter may not like the 1.9k xover point. I would try for 2.2-2.5k with that one.
Wolf

[crossbound]

That tweeter may not like the 1.9k xover point. I would try for 2.2-2.5k with that one.
Wolf

Thanks Wolf. How did you choose that higher crossover point? Is that from personal experience working with it? The reason I'm asking is that to me, just looking at the response curve, it looks fine. Seems looking at the specs sheet doesn't tell the whole story. :-)

[WernerM]

The higher crossover point is because of the Fs of that tweeter. PE lists it at 1kHz, but the spec sheet shows approximately 1.2kHz. Normally you want to cross a tweeter at least 1 octave above its Fs to avoid possible distortion. That would be a crossover point around 2.4kHz.

[crossbound]

Okay. Got it!

[crossbound]

That's it.. I think I'm done now. hopefully

[WernerM]

That looks better. I'm probably being picky, but I would still try a little steeper on the tweeter or a little higher. 23dB down at Fs may be sufficient, but 30dB would be better I think. I'd let Ben chime in before you get discouraged with my response. You have done a very nice job. Could you post the impedance phase and turn on the power response in the Fr section and repost with that as well?

[WernerM]

One thing you could try for additional practice if you wish is to lower the first cap value and raise the inductor value slightly. This would make a steeper slope without going fourth order iirc.

Oh and turn on the overlay to view the reverse null

[Wolf]

Agreed that we really need to see the impedance/phase plot. As to the Fs being so far below reference, he's already comped the Fs a bit by using the resistor across the tweeter. It might not be a problem. Listening to a male vocal can usually tell you whether it has some nasality and buzzing sounds coming from the tweeter if the Fs is not comped enough. If the woofer still rings at you a bit, you can try a LC across the woofer of about 0.1mH and 7.5uF to start with, adjust as necessary.

I think you have a good place to start as long as your offsets and BSC approximations were close.
Later,
Wolf

[crossbound]

There is so many details that need to be accounted for. I'm not discouraged at all. I feel like I'm dragging along this thread and annoy you all with all these beginner questions and confusions. :-) hope that's not the case.
If I remember correctly I have turned on the overlay in the past, but it didn't seem to show me anything different. I'll have to confirm that though. I usually flip the polarity on the tweeter briefly to so how much the reverse null dips down (I assume that is acceptable way of checking it)

Wolf when you talk about the woofer possibly ringing, are you looking at the woofer breakup starting at around 5kHz? And to try to push that even further down?

Not sure if I'll have time tonight, but will post updates by this weekend.