Budget project coming...

jr@mac

So, despite the fact that PE is undercutting their own customers with the so-called "C-Notes" (a name that was used in a high profile Iron Driver entry before being co-opted by PE), I feel it is time to create an alternative using the new 4" woofer from that new bookshelf they are offering. While I cannot compete with the pricing of the C-Notes, I believe I should be able to cobble something together that will compete on a SQ level. 

Let's face it: budget kits at a discount are removing the motivation for people to "build to learn". I am unhappy with the sheer number of kits available, along with the seemingly endless refrain of "build a kit build a kit BUILD A KIT BUILD MY KIT!!!!" - so I feel I should shut up and do something budget oriented. 

OK, (mostly) off the soap-box. That all being said, I am going to build a small, quick, (hopefully) nice sounding 4" class 2-way using Dayton drivers. The woofer will be, as mentioned, that new 4" and the tweeter will be the waveguide loaded Dayton clone of the little Vifa tweeters. I have no reason to expect a complex crossover, and no reason to expect anything less than performance well above its price point. 

Because it is cold outside and just routing driver openings will be less-than-exciting, I elected to go with the PE 0.23 cubic foot flat-packs. Not planning on anything special on the baffles, since anyone who might build these (not likely due to the dynamics of the wider DIY community adhering almost exclusively to the "big three" designers) is probably not interested in duplicating complex baffles. 

So what we have is a very interesting response curve on the 4" woofer. Some others have pointed out what appears to be build in baffle step compensation. I have seen this on a very few drivers, and it is why I expect a simplified crossover similar to the one used in the Dayton bookshelf. A lot of our advanced work in crossover design focuses on minimizing baffle effects related to just such a thing - that resulting annoying, honky hump is my nemesis.  I expect to see a fairly flat in-box response, which should yield a smaller than normal coil for a fully baffle step loss compensated design. Take care of some of the hashing up top, and it will be pretty swell.

The tweeter has enough of a waveguide that baffle effects should also be minimal. I would not be surprised if a L-Pad for some attenuation and protection at resonance plus a single cap would not suffice. 

Anyways, back to work on this lovely Saturday!

PWRRYD

I have drawn up plans to build an MTM with those woofers and that tweeter, but decided not to order the woofers because I simply have way too many other projects planned.  As you know I really like that waveguide tweeter.  It measures and sounds very good.  I bet your Z offset is almost zero with that sized woofer.

I'm glad that woofer works so well in a smallish enclosure because as someone else commented on PETT, 4" woofers look stupid in big boxes.

I look forward to seeing your distortion measurements of that woofer.

Tom_S

I'll be tuned in for this one! That's a great combination of drivers for a simple, budget design.Yeah - if JR's distortion measurements look decent, you can bet they'll be flyin' off the shelf.

isaeagle4031

I'm with you Craig. Too many drivers sitting here currently to even consider buying more. I do think that the Dayton and the $12 Tymphany 3/4" would work vey well together 

D1PP1N

I have been wanting to build a solid budget 2way that i can build for people that have gone out of their way to help me. Most stuff ends up at $200 and thats not realistic to be giving away. 

ani_101

My budget builds ends up at the 500$ mark, but that is the least I am satisfied with. Either the performance is not there or the cosmetics leave a lot to be desired or the XO turns out be birds nest or a humongous box. OS TM is good budget build. JR's last budget build with the MCM woofer disappeared... need a good budget build in the 150$ mark 

jr@mac

That MCM build is still 100% doable via Newark. It is an OS/C-Note killer for similar money.

Turn2

jr@mac said:

That MCM build is still 100% doable via Newark. It is an OS/C-Note killer for similar money.

I have no experience with the C-Notes, but would put that MCM budget build a cut about the OS's without a doubt. Curious to see how this project progresses. I've seen good reception for projects with the .23 cu. ft. knockdowns, both for gifting and otherwise.

Wolf

I would place my Sophomores above the OS as well, and those weren't that costly either, as I built them for $100. (Mike- you heard them in Grand Rapids this year) Scott did a Black Box entry that I feel was solid for $150, but I don't know what he called it. I used the M5N as well in my Mn-14, and those were about $150 as well; the 25-1719 I swapped in for the 25-1414, and they sound a lot better!

I don't think I got to hear JR's project in question, unless it was at the last Chicago event.

I also think that new 4" woofer will be an interesting specimen.

ani_101

Ben, I don't recall the Sophomores - what drivers did it use? Where would you classify your stances - other than the cabinet construction, it should be an easy build.

D1PP1N

I think the sophomores were the purple pair? I could be wrong on the color. I think the stances are a $300ish build when i priced it out. I think trying to limit the driver costs to $20 per driver would be good. That gives you like $20-40 for the crossovers (npe) and high gauge inducters. 

ani_101

yep, pretty tight. Full Range anyone? 3"FR with F3 in 40's 

Wolf

http://s18.photobucket.com/user/wolf_teeth_speaker/library/Sophomores?sort=3&page=1

Writeup:

http://techtalk.parts-express.com/blogs/wolf/1193993-“sophomores”-writeup

Wolf

I had 3 attachments there, where'd they go?

Wolf

IMG_2341.jpg

I figured it out...

IMG_2339.jpg

ani_101

Thanks, the images jogged my memory. Search for the Sophomores on the PE forum brought up too many entries and none had the image.

hifiside

Got a couple pairs. They look like nice little woofers. I have to build a couple Bluetooth speaker with them.

hifiside

I got them thinking they look similar to the TB's and using them as a mini subwoofer.

jr@mac

My pair showed up today The frame, while attractive, is absolute shit. Word of caution, the surround on both of mine began to visibly distort (yes, I use that word deliberately) within a few mm of excursion when tested with a battery. Will probably not be too linear at high excursions regardless of the models. I see that often on cheaply built drivers. The HiVi F5 I tested had a problem with it, for example. Not sure what part of the manufacturing process leads to that, possibly inconsistent glue placement? It will definitely limit linearity as it exits the gap, however. 

Anyways, they are actually a very nice looking little driver and should be a fun little project. It models fairly well in a tiny box and should do reasonably well in a more-or-less nearfield application. 

ScottS

Wolf said:

I would place my Sophomores above the OS as well, and those weren't that costly either, as I built them for $100. (Mike- you heard them in Grand Rapids this year) Scott did a Black Box entry that I feel was solid for $150, but I don't know what he called it. I used the M5N as well in my Mn-14, and those were about $150 as well; the 25-1719 I swapped in for the 25-1414, and they sound a lot better!

I don't think I got to hear JR's project in question, unless it was at the last Chicago event.

I also think that new 4" woofer will be an interesting specimen.

My M5n build is called the Mercury.  Tweeter is the Vifa BC25SC06-04, which has been a go-to value tweeter for me.  I think it turned out quite well, and it has subsequently sold - so at least one other person liked it.
.
I have some details on that project posted on the PE forum.  Used the PE 0,25 cu ft. box and a series crossover, which reduced the parts count a little.  

The Sophomores were very good.  When I first saw them, I wasn't expecting too much - but that quickly changed when listening started.

ScottS

JR - I will be watching this build.  Very small and/or very cheap fits a lot of needs well.  That 4" woofer looks pretty good for $12.  Might make a nice boom box or sound bar option.

jr@mac

PWRRYD

Awesome JR!