AHall Posted January 12, 2019 Share Posted January 12, 2019 Did some experimenting today with the subwoofer. When it is tucked into its hole its size is very manageable. I forgot how massive it is when the behemoth is actually pulled out into the room. It makes the jubes look like bookshelves in person. 75” tv for reference. The measurements were takin from my middle couch seat 14ft from the subwoofer horn mouth. I did the initial peq using Chris’s thread. And did so with all ports open as they came from the factory. I’m uncertain what I’ve lost up top at the expense of lower performance at this point. And I’ll try to see if there is any room for optimization in the freq response with the second port closed. To keep things consistent I made sure not to move the mic or change any peq along the way. Id like to hear everyone’s opinions on this heresy. 2 Quote Link to comment Share on other sites More sharing options...
AHall Posted January 12, 2019 Author Share Posted January 12, 2019 1 Quote Link to comment Share on other sites More sharing options...
jwc Posted January 12, 2019 Share Posted January 12, 2019 2 ports closed. Sweet. Quote Link to comment Share on other sites More sharing options...
jwc Posted January 12, 2019 Share Posted January 12, 2019 As big as the freaking subwoofer chamber is.....you could smooth out with three ports closed. Wonder if the driver could handle it. Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 12, 2019 Share Posted January 12, 2019 I'd use a roll of foam to close the ports, myself. If you close too many ports you'll make the others chuff. . 1 Quote Link to comment Share on other sites More sharing options...
jwc Posted January 13, 2019 Share Posted January 13, 2019 Or a roll of socks Quote Link to comment Share on other sites More sharing options...
AHall Posted January 13, 2019 Author Share Posted January 13, 2019 I used a rolled up T-shirt and capped it with duct tape. It’ll be fine for what I’m doing Quote Link to comment Share on other sites More sharing options...
seti Posted January 17, 2019 Share Posted January 17, 2019 Did anyone ask Roy the ramifications of these changes as I'm sure they are there for a reason...? Quote Link to comment Share on other sites More sharing options...
AHall Posted January 17, 2019 Author Share Posted January 17, 2019 26 minutes ago, seti said: Did anyone ask Roy the ramifications of these changes as I'm sure they are there for a reason...? I got his reply a day or two ago. Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted January 18, 2019 Share Posted January 18, 2019 That is a big subwoofer !!! Quote Link to comment Share on other sites More sharing options...
seti Posted January 18, 2019 Share Posted January 18, 2019 8 hours ago, AHall said: I got his reply a day or two ago. HELLO AND????? Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted January 18, 2019 Share Posted January 18, 2019 7 hours ago, seti said: HELLO AND????? What seti said 😄 Quote Link to comment Share on other sites More sharing options...
AHall Posted January 18, 2019 Author Share Posted January 18, 2019 He mentioned he went with the 7 port design due to high spl levels for cinema use. I should be good with the current 5 port configuration and have enough spl to go deaf. Closing another port will get me lower but might be approaching the limit of the amount of spl the 4 ports will generate and create chuffing. I will need to play content to see if I run into this issue. So my plan is to leave it how it is with 2 ports closed. I’ll play some music and movies at high spl to see if I get any negative results. Then I’ll repeat with the third port closed. I don’t plan to attempt closing a fourth port. And I may try to do a slug test to see when compression occurs with each. After I’m done I’ll decide if 2 ports or 3 is better for my use. If we are -3db at 15-16hz currently and didn’t lose any usable home performance id say this tuning is a winner. And maybe just a bit better with 3 if it doesn’t chuff. 1 Quote Link to comment Share on other sites More sharing options...
seti Posted January 18, 2019 Share Posted January 18, 2019 3 hours ago, AHall said: He mentioned he went with the 7 port design due to high spl levels for cinema use. I should be good with the current 5 port configuration and have enough spl to go deaf. Closing another port will get me lower but might be approaching the limit of the amount of spl the 4 ports will generate and create chuffing. I will need to play content to see if I run into this issue. So my plan is to leave it how it is with 2 ports closed. I’ll play some music and movies at high spl to see if I get any negative results. Then I’ll repeat with the third port closed. I don’t plan to attempt closing a fourth port. And I may try to do a slug test to see when compression occurs with each. After I’m done I’ll decide if 2 ports or 3 is better for my use. If we are -3db at 15-16hz currently and didn’t lose any usable home performance id say this tuning is a winner. And maybe just a bit better with 3 if it doesn’t chuff. Ahh... I might have to try that sometime but seriously how much lower do you need to go lol.... Quote Link to comment Share on other sites More sharing options...
glens Posted January 18, 2019 Share Posted January 18, 2019 The way those curves were progressing, I'd be tempted to block off all the ports and take a measurement. Could probably sacrifice a few dB of overall output if it ended up table-flat... Quote Link to comment Share on other sites More sharing options...
AHall Posted January 18, 2019 Author Share Posted January 18, 2019 10 minutes ago, glens said: The way those curves were progressing, I'd be tempted to block off all the ports and take a measurement. Could probably sacrifice a few dB of overall output if it ended up table-flat... I think you’d lose a lot of your spl going from horn loaded ported to hornloaded sealed in a big box. The response is already pretty flat and would be borderline inaudible. Most graphs are in a 5-10db scale usually. I like everyone to see what’s going on better. I have the xilica dsp controlling this as well. Quote Link to comment Share on other sites More sharing options...
glens Posted January 18, 2019 Share Posted January 18, 2019 Oh, I hadn't expanded the image enough to note the vertical scale. Agree that looks quite good. Quote Link to comment Share on other sites More sharing options...
AHall Posted April 1, 2019 Author Share Posted April 1, 2019 Current update. Redid some eq. This is the current response at the listening position. Added a bit of a house curve into the peq. Still using 2 ports closed. I haven’t noticed any negative results as of yet. 1 1 Quote Link to comment Share on other sites More sharing options...
MenloBob Posted April 2, 2019 Share Posted April 2, 2019 Can you hear the improved response? Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 3, 2019 Share Posted April 3, 2019 On 1/13/2019 at 7:55 AM, jwc said: Or a roll of socks I used to use a roll of socks to plug the ports of my old Marantz Imperial 7s in college! Quote Link to comment Share on other sites More sharing options...
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