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Impious

SSA Tech Team
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Posts posted by Impious


  1. About ready to start measuring, finally.  Wanted to this weekend but didn't have the free time I thought I would.  Just got them to this point a few minutes ago.  

    Must say I really like the look of the rear mount with roundover on the wideband.  

    Wish I would've swapped the port on the right speaker so the port was on the outside on both.  Not that it matters acoustically.  It's purely cosmetic.  Just would've been nice to have the forethought to plan that look better.  

    20210912_191410.jpg

    20210912_191418.jpg


  2. Been using CSW Model6's in my home gym for the past year.  While they were good enough for the $25 I paid for them, they have their weaknesses and roll off hard at 100hz.  

    I've had some Coustic Design Reference 7" mids sitting around for about a decade.  Despite being car audio mids, they're old enough that they actually have more home audio TS parameters.  Figured I'd put them to use and gain some more DIY experience at the same time.  

    Trying to ball on a budget here as these speakers aren't uber important, more of a learning experience than anything.  Decided to go with a Woofer Assisted Wideband arrangement for a couple reasons.  First I wasn't sure of the usable high FR of the mid but I'm sure with the ancient technology involved it's going to be unimpressively low.  Second I was trying to really pinch pennies here and getting a ($10-15) cheap tweeter that will play low enough to mate with these modbass was unlikely.  The Vifa TC9, however, is only like $7 and will easily play down near 100hz if desired.  


  3. 9 hours ago, ///M5 said:

    Holy shit dude.  Nice work.  Somehow I completely missed all the measurements.  Work life balance has been terrible lately.  Curious to know what you used although it seems I am really late to the convo.  Out of all threads, not sure how I didn't see this.

    Thanks :) I measured in REW with a Dayton EMM6 mic and M-audio Mobile Pre mic preamp. Z curves were taken in Limp.  Modeled the xovers in a mix of Xsim and WinPCD.  Those graphs and schematics are from Xsim because at the time I couldn't figure out how to model the tank filter in WinPCD (although I've since figured it out).


  4. 17 hours ago, lithium said:

    Looks sweet. Planning to take measurement or just audition them 

    Both.  The other measurements were all done outside.  I'll probably measure these inside just to make my life 183x easier.  

    I should have all the parts in by tomorrow.  And I happen to have Mon and Tue off as well :) So I'll probably spend most of the next 4 days demo'ing and measuring them to see what ends up working in reality


  5. Here's probably one of my top contenders as far as phase and response go.  4th order on the woofer with a zobel and tank filter, tweeter is second order.  My last crossover is just a variant of this - slightly different values for some of the inductors and caps to shape the response a little differently.  But overall layout is the same.  I have a 5ohm resistor on the tweeter to drop the response a little to keep it from being on the bright side, but I am also going to try a 4ohm which would bring the response from the tweeter up to pretty close to flat.  We'll see which way sounds best in reality.

    7empest Xover FINAL Opt 1 Schematic.jpg

    7empest Xover FINAL Opt 1 Null.jpg

    7empest Xover FINAL Opt 1 FR.jpg


  6. So with a little help I came to realize that the dip in my initial measurements from 2-3khz was likely an issue with my measurement system somewhere.  So I went through and created a new cal file to basically pretend it didn't exist :) My new initial measurements look a little different than above, but eliminating that dip in the tweeter response is really the main difference.  Spent way more time than I care to admit working on different xover sims, but I learned a bit each time.  I'm far from an expert but definitely better than when I started a few weeks ago.  Came up with 3 main xovers that I'm going to try.  This is probably my favorite.  The response isn't the flattest, and the reverse null isn't the best of the bunch...but it's the only alignment that is a 2nd order on both the mids (with a tank filter) and tweeter so the part count is the lowest and it's the simplest design.  I think there's something to be said for simplicity.  Guys like Zaph and Jeff Bagby (RIP) always tried to design with the least parts possible. 

    I have $160 worth of crossover components on their way to me from PE. to try all three designs.  So hopefully out of that I'll be able to make something that sounds decent :) I just went with non-polarized electrolytics for the caps because, well, they were 1/10th the cost and I'm a tight ass with money, the actual sonic differences are arguable at best, and I may have something in the next couple months that'll require some cash to fund properly.  We'll see.  

    7empest 2nd Order Schematic.jpg

    7empest 2nd Order Null.jpg

    7empest 2nd Order FR.jpg


  7. I think what you are missing is that companies like Stereo Integrity work with a build house or with vendors who do large order OEM only production runs.  If you want to build 1000 drivers, they'll work with you.  If you want to buy 2 VC's, spiders or cones from them, they likely won't even bother responding to your email.

    The guy who used to run PSI Car Audio was named David and was one of the main guys at the old RE.  They have the option to request a custom built sub.  https://psicaraudio.com/request-form/

    He also ran https://fixmyspeaker.com where you could buy custom parts/recone kits but there is a header that says they aren't taking new orders.

    Anyways - my suggestion would be to either request a custom sub through PSI and ask if they can ship it unassembled, or see if he can or can direct you to someone who would be willing to just sell the parts.


  8. 10 hours ago, lithium said:

    Weird how much lower the tuning came out, maybe you can seal the port and see where its at for a sealed enclosure. 

    Yeah it's a little odd.  But honestly now that I'm working on the xover I'm not mad.  On the woofer side the response is flat down to 30hz with an F3 in the mid 20's.  I can live with that :)  


  9. Okay so I guess this is the starting point for the FR.  We will see how it goes from here :)

    Also that hiccup at what turns out to be approx 120hz in the Z graph shows up as a -1db dip in the FR response :/ 

    7empest Raw FR Measurements FINAL.jpg


  10. Here's the impedance sweep for the Anarchy's.  Learned a few things:

    1) For some reason tuning ended up being 25hz instead of 35hz?  No idea.  I know it's not a measure twice, cut once issue with building the cabinets.  Measurements there are solid.  I figured I'd be off a few hz one way or the other....but 30% was a little unexpected.  I'd considered that maybe it's an accuracy issue with the measurement....but the Anarchy's are infamous for having a cone resonance around 4200hz which is about spot on in the measurement.  So....

    2) I had poly fill stuffed in the bottom of the enclosure to start but when I started measuring impedance I had a nearly non-existent impedance peak at tuning.  Removed the polyfill and the impedance peak looks much better than how it was.   

    3) I knew about the hiccup at ~4200hz which is a cone resonance.  Not sure what's going on at 150hz...enclosure resonance maybe?  Internal reflection?  Not sure. 

    Anyways.  I had the FR sweeps all done, but going to rerun the sweep for the Anarchy's without the polyfill since based on the Z curve I'm going to be leaving that out.     

    7empest Anarchy Impedance Image.jpg


  11. Welp, as usual this shit is taking way longer than I anticipated.  Didnt help I had to spend all day Sat fixing my dryer instead of working on my speaker project :wacko:

    But, progress was made.  Got my binding post plates installed, baffle mounting bracket pieces put on, holes drilled and countersunk, T nuts installed and started on the cabinet damping.  Also realized I forgot about needing to measure the impedance curve....really wish I'd thought about that when I placed my order at PE  >:(  

     

    20200907_220841.jpg

    20200907_220928.jpg

    20200907_221020.jpg


  12. I thought about ditching the Seas and just going with the Apollo's, but I wanted to try my hand at designing the network.  Who knows, this may turn out to be an epic fail and I'll go that route instead  :)

    Just placed my PE order for my binding post terminals, a couple caps, T nuts and a few other things.  Should arrive in just a couple days, so the cabinets should be in a position to start running FR sweeps this weekend or 1st of next week.  I may need a bit of help from Sean when I get to that point.  It's been a minute LOL

    I also learned that if you drop some items in your cart @ PE and leave them there without checking out, PE will email you a coupon for 10% off after a day or so ;)


  13. 25 minutes ago, Tirefryr said:

    Nice to see you back!  Do you still have a lot of Design Reference stuff?

     

    I have 1 set of the 306P 6.5" mids left.  Thought about grabbing a cheap tweeter and turning them into a little bookshelf speaker for my gym if this turns out well.  


  14. 2 hours ago, dem beats said:

    I have a half rack, decent adjustable bench from hois, preacher attachment, leg curl attachment, a pair of 90# power blocks, ez curl bar, and only ~400 pounds for the heavy bar. 

    I really want to try one of those hip belt squat machines. If they feel as good as they look I need one of those. 

    Man 2 months ago those powerblocks were worth more than gold.   


  15. 2 hours ago, nigel said:

    Ohio power bar.  One great quality, all around versatile bar right there.  Will last you your whole life.  Once you get the bug on home gym stuff, hold on tight, you will never have a positive bank account again... I've got an "equipment fund" jar on top of my fridge in the garage... If I don't have the cash in the jar for it, I don't buy it.  Otherwise, I'd be in some serious trouble with what I want to buy.

    My wife was giving me a hard time about how much it cost.  I told her it'll be the last bar I'll ever need to buy.  I need to buy some more 45's and I'd like to upgrade my Fitress Gear bench to a Rep.  But otherwise I should be pretty set.  For now.  I think LOL


  16. Bought everything I'd need to install a system in my Durango last summer.  Then when it came time to start installing it all realized I have zero motivation to do so.  78% feel like selling it all to replenish what I spent on the home gym, 22% of me still fantasizes about having a badass stereo.    

    I've had a sextuplet of Exodus Anarchy's sitting around unused for literally 10 years.  Might turn those into something for the house to see if it squelches the audio bug for me.   

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