db_speakerbox Posted July 6, 2015 Report Share Posted July 6, 2015 Great vids! All of them shot with the gopro? Love the plexi btw Link to comment Share on other sites More sharing options...
Mrop Posted July 10, 2015 Author Report Share Posted July 10, 2015 Great vids! All of them shot with the gopro? Love the plexi btw Yes, Go Pro 4 Black Edition, 120FPS 1080p and the "Flex" -video is with Nikon D5200 1080p 30FPS (Stock lens). First test 153,75dB @ 28Hz 155,00dB @ 48Hz Now i start to make the port... planning to do a 2150cm2 port, and tune the ported section to 48Hz. More vids: www.peranurkka.net Link to comment Share on other sites More sharing options...
db_speakerbox Posted July 11, 2015 Report Share Posted July 11, 2015 Nice scores! Vids are really cool. Thinking more and more about getting the 4 now lol. Sorry I dropped the ball on the sealed calculations. I totally forgot about it. My take on it is this: Assuming 450 liters sealed volume, your sealed resonance is ~39hz by calculation. This is purely woofer vas, fs and volume. The cabin will have some effect to this of course, but it shouldn't have much. With the orientation of your subs, you will have some tunnel effect of port that will sometimes show up in the impedance sweep. Looking back at your sweep that looks to be possible. Also vehicle sealed and combination of windows and doors open will effect this as well. All that being said, I'm not sure what your overall goal is with this build so here are my thoughts. If you want highest spl numbers, it would be best to shrink down the sealed some to bring up sealed resonance and tune 48hz or so. If you want loud low, I would keep it as is. Tune ported section to 42hz with around 3350 cm2. You could tune at 48hz as you planned, but you would get much more efficiency tuning closer to sealed resonance. 2150 cm2 is rather small I think. Thats usually the range I use for 2 18's. I really wasn't trying to write a book here lol. I would like to see you try my port recommendation just to see if you like it. Good luck and again congrats on scores so far! Link to comment Share on other sites More sharing options...
Mrop Posted July 15, 2015 Author Report Share Posted July 15, 2015 Thanks for the calcs!I am aiming for high SPL, but i want to try and test and see what happens when and why, more than just aim fast to the highest SPL.I planned to make the enclosure as big as possible, so i have the change to cut it smaller. The 3350cm2 sounds quite large, as the open port area now is somewhere 4000-4500cm2... I have noticed that the box goes super low when doors open, and stops playing all when sealed up. That made me think that perhaps the box does not works properly now. -Doors open the cabin seems to work as ported box and the tuning can be changed with opening doors and windows... -Doors closed the box works like sealed. The 60Hz range slams painfully hard, lows does not work at all, but when i open 5-10cm both windows the lows just hammers in I think that i need to create some pressure inside the ported section to make the 4th order work.... The doors will only lower the tuning when opened/closed, but i need to have some pressure built up before i can test it and get the 155+ on TL.i aim for 160. No matter if it hits in kickpanel or window, but i want to break the 160 www.peranurkka.net Link to comment Share on other sites More sharing options...
db_speakerbox Posted July 16, 2015 Report Share Posted July 16, 2015 I think 60 is doable. Just takes a lot of time and patience to get the whole system working together with a bandpass for the best results. Yes you will get more pressure with a smaller port. Just try to be careful not to exceed 25 ms2 velocity. Regardless of port area, I would for sure atleast try to get the tuning down to 42-44hz range. As it is now the tuning is so much higher than sealed you lose a lot of efficiency. Of course this is all in theory. This is spl where nothing makes sense lol. Most of my builds are in suvs. Ive never even driven a volvo. Keep the progress updated! Link to comment Share on other sites More sharing options...
Mrop Posted August 5, 2015 Author Report Share Posted August 5, 2015 I tried smaller port (2250cm2)I hated the sound.I want to keep my 25-60Hz -range Next step: M4a to 0,25ohm Video about a meeting i participated at. www.peranurkka.net Link to comment Share on other sites More sharing options...
zxsonnyxz Posted August 9, 2015 Report Share Posted August 9, 2015 Theese Finnish guys and their sisu STD Passat Build 151db+STD Omega BuildMitsubishi Colt Build - Alpine|Focal|PeerlessHome Stereo BuildSmall Tang Band build - 4" fullrangeBox for 4 8"My Saab 9000 Build- I'd be very happy if you cared to check out the logs and give feedback! Link to comment Share on other sites More sharing options...
Mrop Posted August 9, 2015 Author Report Share Posted August 9, 2015 I did 0,25ohm and it did 155,46dB at windscreen and 157,95dB at kickpanel.I am happy, i have never done a 157,xxhere is a vid from the show i attended.won second place in SPL www.peranurkka.net Link to comment Share on other sites More sharing options...
db_speakerbox Posted August 18, 2015 Report Share Posted August 18, 2015 Great vid. You guys have some crazy dashes over there lol. I thought that port might be a bit small. Did you try the 3350? Getting closer to a 60! Link to comment Share on other sites More sharing options...
Mrop Posted August 27, 2015 Author Report Share Posted August 27, 2015 actually i still do not have a port at that burp i did (157 in the kick).I have made one now: It is a 2100cm2 tuned to 44,4Hz (peaks at 44) results: M4a @ 1ohm 1door open:@Kick 155,30 @ 44Hz (+0,19dB) @dash 153,23 @ 44Hz ( +1,98dB)i rounded port and results:@Kick 155,56 @ 44Hz (+0,26dB) @dash 153,69 @ 44Hz (+0,46dB) Tested imp rise at 1 ohm:20Hz 86,4V 39,0A Z=2,22 W=3369 30Hz 88,1A 38,3A Z=2,30 W=3374 40Hz 90,8V 25,2A Z=3,60 W=2288 50Hz 92,7V 23,2A Z=3,99 W=2150 so i propably will be gettin somewhere these, when i lower the amp to .25: @Kick 158,40 @dash 157,90 Still alot work to do.Next, i will try a bigger, higher tuned port, then make a 40hz port.I see a standing wave happening at 20 - 40 Hz...I accidently burped 148+ at 20Hz doors closed... Did another try and it did 147+ at 20Hz... Never happened again also i tried some bagtrick: Getting closer!! www.peranurkka.net Link to comment Share on other sites More sharing options...
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