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post #12661 of 12669 Old 07-24-2015, 05:48 AM
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Originally Posted by LTD02 View Post
is it possible that you are one full cycle off?
I don't see anything to suggest it's a cycle out. For one thing there is nothing in the signal chain to apply a delay but another thing is that a fixed time delay is a phase adjustment that varies by frequency, it seems pretty unlikely that such a delay would still enable a perfect fit to the response over a span of more than an octave.

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edit: also, what's going on with getting more spl (cd side) with phase reversed?
it's not the nature of the phase response. The woofer being so far in front really sends it completely out of alignment with the CD, they are somewhat aligned around 1kHz with the same polarity but it shifts to around 2kHz with the CD reversed. This means that the summation is constructive around 1kHz but destructive around 2kHz in the normal polarity case but the roles reverse as polarity is flipped. A pic to illustrate

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post #12662 of 12669 Old 07-24-2015, 08:23 AM - Thread Starter
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Originally Posted by 3ll3d00d View Post
A pic to illustrate
out of curiosity, why would you choose such a mixed phase response through the crossover region? is there another advantage that you are trading that off against?

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post #12663 of 12669 Old 07-24-2015, 10:53 AM
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Originally Posted by LTD02 View Post
out of curiosity, why would you choose such a mixed phase response through the crossover region? is there another advantage that you are trading that off against?
the speakers will be beneath the screen, i.e. below ear height, hence the design was to use a angled baffle to fire such that on axis is at ear height at the LP. However this means the woofer is too far forward & I can't see a way to get the phase response into line. I didn't think the AC of the woofer would be this far forward tbh.

I had been thinking of changing the design anyway so this problem is quite handy in that sense. I'm now going to go with a flat baffle for the woofer and house it in a separate enclosure. I then intend to put the horn on top in another enclosure with a slight rake to the baffle and I might also rear mount the woofer to claim back another cm or so. This should fix the phase response alignment nicely.
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post #12664 of 12669 Old 07-24-2015, 10:30 PM - Thread Starter
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I see. that shouldn't (theoretically) create a problem though--no reason why a forward aimed main lobe can't be tilted up by aiming the speaker up physically or sloping the baffle upward.

I took a shot at trying to recreate your phase reponse in winisd (as that's all I've got to work with).


while not a perfect simulation, it is pretty close.





the big problem appears to be the different "roll rate" through the crossover region.


now to try to "fix" it. first, the net slope of the woofer through the crossover region should be about the same as the total net slope for the tweeter. I used a 4th order low pass to get things going. but that still left quite a mismatch out-of-band, so I applied another 4th order up around 5500hz to match up the upper end.





now the slopes are roughly the same through the crossover region (as well as outside of it), so with a simple 180 degree phase reversal, they will overlap nicely.


those would be net acoustic slopes btw and the precise values aren't important. just provided to give some possible clues for where to look for the fix.
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post #12665 of 12669 Old 07-25-2015, 02:53 AM
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Thanks for the suggestion. I will go back through some of my various sims and play around some more.
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post #12666 of 12669 Old Today, 12:00 AM
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well, being that this year has been VERY busy for me, and I was just plain lazy it's taken me a while (I bought the dang speakers in October 2014)... I got the first 2 of my 4 surrounds wired up (switched to 5.1 for the next week, maybe 2 until I can get the last 2 speakers up for my back surrounds)... I decided I was tired of waiting and cutting angled cuts so I bought the Flat packs from Erich over at DIYSoundgroup to finish up the boxes and let me say this. they are EASY to assemble. I'm not the woodworker, my buddy is, I'm just good at designs and tweaking stuff. long story short, I built the boxes over the weekend and finished running them with duratex in 24 hours... the last 2 boxes just need duratex and I can toss in the components

I'm hanging them on my side walls with french cleats from Home Depot and they blend seamlessly with my SEOS 15 Cheap Thrills. the clarity on these things are WAAAAAAAAAAAAAAAAAY better than my Polk M30's, giving off effortless detail that I didn't realize was in the audio track before. absolutely love that they're hung up near the ceiling and angled down so I don't have to have my sides on stands anymore taking up space. here is the pics I took to show the process
















I'll be sure to listen to them for the rest of the week and post a review over at Diysoundgroup.
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post #12667 of 12669 Old Today, 09:09 PM
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Flatpacks are just simply wonderful ,
some smart guy with a good idea looked around for the laziest man he could find and explained what he wanted.
Lazy guy to the rescue.

In the last 25 months I have built 6 subs and helped on another 2, all from full sheets and I had fun (I keep telling myself) . .

but those volts 6 kits were just so sweet, nice to feel working smarter rather than harder.

Waiting for your review . . .

what's next?

DIY FAN Denon X5200 , Emotiva UPA7, for 7.3.4 ATMOS/DSU/NEO:X SHARP 80" LED/LCD
FL/FR: DIYSG Fusion 15's , C: DIYSG 88 Special , SL/SR: RC3II , SRL/SRR: F-3Towers, TF & TR: SLX, FW: Volt 6
2 30" BF THTLP'S , SUBMAXIMUS, 2 x Inuke6000DSP & 2 driverless LHORN cabs
http://www.avsforum.com/forum/401-di...rs-subwoofers/
www.avsforum.com/forum/155-diy-speakers-subs/1485120-submaximus-large-front-loaded-horn
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post #12668 of 12669 Old Today, 09:10 PM
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Flatpacks are just simply wonderful ,
some smart guy with a good idea looked around for the laziest man he could find and explained what he wanted.
Lazy guy to the rescue.

In the last 25 months I have built 6 subs and helped on another 2, all from full sheets and I had fun (I keep telling myself) . .

but those volts 6 kits were just so sweet, nice to feel working smarter rather than harder.

Waiting for your review . . .

what's next?

DIY FAN Denon X5200 , Emotiva UPA7, for 7.3.4 ATMOS/DSU/NEO:X SHARP 80" LED/LCD
FL/FR: DIYSG Fusion 15's , C: DIYSG 88 Special , SL/SR: RC3II , SRL/SRR: F-3Towers, TF & TR: SLX, FW: Volt 6
2 30" BF THTLP'S , SUBMAXIMUS, 2 x Inuke6000DSP & 2 driverless LHORN cabs
http://www.avsforum.com/forum/401-di...rs-subwoofers/
www.avsforum.com/forum/155-diy-speakers-subs/1485120-submaximus-large-front-loaded-horn
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post #12669 of 12669 Old Today, 09:18 PM
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what's next?
Self assembling crossovers.
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