Budget diy Dayton 2-way vs budget brand monitor

[iglow01gt]

Thanks for reporting your experiences, they are greatly appreciated.
I am wondering if you could state what drivers that you are using, because so many were mentioned and they are all available in 4 or 8 ohm versions.
From the graphs, woofers appears 4, but tweeters look higher, so I am not certain.
Thank you,
Tim

[tom_s]

You are correct on the TCP115-4. The DX20 is also the 4 ohm version. I do need to listen to these in another room. My man-cave is a little bright sounding, probably due to the ceiling reflections and lack of sound absorbing furniture. My 21 yr old son notices that right away, but I guess I'm used to it now. He said these are very clear sounding while still being smooth. He wondered if they were a touch too bright, so I dropped a 4.7 ohm in place of the 4 and he seemed to like that better - but that's in this room. If you build it, you might want to buy 4, 4.3, & 4.7 ohm resistors to tweak for your own room.

[Wolf]

I would pop a 25 ohm across the tweeter and see if the -30dB ripple at 1k goes away. This will help damp the Fs of the tweeter. If BSC is not enough, just increase that bottom coil. Otherwise, this looks pretty good.
Wolf

[tom_s]

Wolf - Thanks for the tip. I was hopeful, but even dropping to a 15ohm didn't knock that hump down in the sim. It just dropped the overall level of the tweeter. Oh well...I'm liking these enough to bring them upstairs and see how they sound in the living room. If that goes well, I'll solder up the caps & coils on a little board, screw it down inside, and call it good. I'll probably order up parts for another pair to give our oldest for his birthday. I'll pretty them up with some nice veneer - maybe do something similar to prxprx's cad drawing.

[Wolf]

One more thing, try a 0.1uF across the BSC coil. This should knock down the breakup more for not much outlay.
Wolf

[tom_s]

Just a quick update - I thought they needed a little more tweaking after hearing them in the living room. Just incremental changes to a few parts. Not bad for my first serious attempt at a series crossover. Time to solder these up and see how these fare as near-field monitors at work.

[tom_s]

Thanks! I look forward to reading your thoughts (that sounds stranger than I meant) if you find time to try them out.

It looks like post#40's SIM graphs and my Vituix SIM results of the same drivers+XO are a little different (primarily with my SIMed TCP115-4 showing a hump from 2k-4k and not really dropping and crossing till nearly 5khz) so I'm curious where the difference might be coming from. I think Prxprx mentioned using the PE provided FRD/ZMA files (which I'm also using).

Sorry, I completely ran out of time this weekend thanks to some more snow and cars that needed to be dealt with.

Here are the sims based on actual measurements. It was pretty easy to dial these in. Might not even need a 2nd coil for more BSC. I have not listened to these yet. Still need to see if I can get the phase tighter, but I thought I read sometimes that just won't happen with a series crossover.

[tom_s]

Here the measurements for the finished DX20 version - Blue is measured @ 24" on axis, brown is the sim. I even have a decent reverse null.

Horizontal polar measurements are at 0, 15, 30, & 45 degrees. Could be worse!

[LOUT]

Sorry, I completely ran out of time this weekend thanks to some more snow and cars that needed to be dealt with.

Here are the sims based on actual measurements. It was pretty easy to dial these in. Might not even need a 2nd coil for more BSC. I have not listened to these yet. Still need to see if I can get the phase tighter, but I thought I read sometimes that just won't happen with a series crossover.

No worries. I'm excited that you might be able/willing to test it out and compare them somewhat from listening at some point, not so much worried about if it happens to take a while to get there.

Nice, those seem to match my plain PE-FRD/ZMA SIMed results a lot more closely (a nice sanity-check for me at least, lol) aside from your measured low-end response under 500-1000hz being a little higher/flatter than I'd expect after BaffleStep losses (maybe that's some room gain in effect?). Probably just the real-world being a little less heavy-handed than my simple SIM and my inexperienced expectations.

[tom_s]

I'm a little late on an update, but I did wire up a crossover for the TD20F last week to compare to the DX20. It's really an apples to oranges comparison since I've been tweaking the DX20 crossover for a while now and only spent 30 minutes with the TD20 version. Thanks to age and some hearing damage, I'm really sensitive to sibilance and I think that's why I don't care for the TD20F. Maybe it's something in the distortion profile? They did sound really open, to use a subjective term. And I didn't feel like what I whipped up was missing too much. Music was not quite as full sounding in the upper bass and lower mids as the DX20F design. That extra inductor on the woofer really makes a noticeable difference. The TD20 design is at least a few dB more sensitive. But it should be, with much less total resistance and half the inductance.

Every ear is different, so if the TD20F works for you, I think that's great! Bottom line - this rushed design sounds even better than the old MK402s. But with those, sadly, you can only take them so far since the enclosure and tuning options seem to be limiting the TCP115. Too bad - the MK402 is much better looking than my little bare MDF boxes. I like the DX20 version enough that they have replaced my budget Peerless 830565/BC25 monitors in my edit suite at work. I've been playing with the tweeter padding resistor - anything between 1.5 - 4.7ohms is fair game. 2.2ohms sounds pretty good using these as near-field monitors. Go higher if you want a more "relaxed" sound. You can even play with a jumper across L1 if using these close to a wall or on desktop. Experiment - have fun - it's what this hobby is supposed to be about anyway!

[LOUT]

Thanks for trying that out and writing back.
Also, might be the distance in the top image, but the bare MDF looks surprisingly good (the edges look beveled?...is that the word?).

[djg]

What an awesome desk. Are those Leicas?

[tom_s]

I wish those were Leicas - I would have sold them and bought more audio toys! Those are just old. I used to find cool vintage cameras at thrift stores, but I haven't seen many good ones lately.

[duanebro]

Awesome work on these!

The TCP115 has "bsc" built in. This is why it works with the simple series xo so well. You may have better results with a normal crossover when changing the tweeter. I did both and found that the series was cheaper...

[PWR RYD]

Great work Tom! Your crossovers are very neat.

[tom_s]

Thanks guys!

Duane - thanks goes out to you for the box tuning. That's sure not my strong suit. It's been a good learning experience. I've been able to see what you can do with a series crossover - and what you can't. Mine sure won't win any awards, but they do sound better than I would have imagined for such budget drivers.

[iglow01gt]

Great project for a reasonable price.
Thank you for sharing all of your work and comments for others to learn from as well.

To be clear, for the enclosure did you use what Duane listed for the Dayton 4 ?
"The Enclosure
The enclosure is 8” tall, 6”wide, and 8.5” deep. Made out of ½” plywood or MDF. I built a triangle port that caused some minor issues.
Instead I recommend a 1.125”diameter port tube 6.5” long installed on the back behind the tweeter Part #260-472 ."

Also, it looks as if the tweeter is offset from the center some?

[tom_s]

I'm glad a few people are following. I've learned a little more too along the way with this one.

I did copy Duane's project on the volume of the box and the tuning. Mine are sure nothing fancy, just 1/2" mdf. Since I knew they would be toed in, I did offset the tweeters a bit in hopes of reducing some ripple. I also used a 1/2 round over bit on the edges. They've taken up residence at work and at some point I'll have to bring them home for a few coats of Duratex and to mount the crossovers inside.