EXPERIMENTAL Quad JBL Devastator Build - Page 10 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 327Likes
Reply
 
Thread Tools
post #271 of 354 Old 02-14-2020, 01:14 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
EXPERIMENTAL Quad JBL Devastator Build

Quote:
Originally Posted by BP1Fanatic View Post
Omg Chris, the PA folks over on diyaudio.com are not getting this concept.


Well, I know very little about live sound, so I have no idea if this would be an effective cab or not.

Mine might get used that way at some point, just because its an impressive subwoofer, but still light enough to be reasonably portable.

The well-protected cones help too.

Chris

Last edited by a77cj7; 02-14-2020 at 01:20 PM.
a77cj7 is online now  
Sponsored Links
Advertisement
 
post #272 of 354 Old 02-14-2020, 01:24 PM
Advanced Member
 
BP1Fanatic's Avatar
 
Join Date: Jan 2010
Location: Columbus, Oh
Posts: 882
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Liked: 286
With them, it's 40-50hz and up....NO musical content below those frequencies. I always come back with the lowest note on a piano is 27.5hz, why not build the enclosure to play that to that frequency.

Sony XBR65x900e / STR-DN1080 / original PS4 / WOW! Ultra TV / Quantum Access Mini PC Stick w/Windows 10 / 8 x Rockville SPG88 8“ DJ PA Speakers / Dayton Audio SA1000 / Kicker 08S15L74 in a Tapped-Tapered Quarter Wave Tube (negative flare tapped horn).
BP1Fanatic is offline  
post #273 of 354 Old 02-14-2020, 01:44 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
Quote:
Originally Posted by a77cj7 View Post
Well, I know very little about live sound, so I have no idea if this would be an effective cab or not.

Mine might get used that way at some point, just because its an impressive subwoofer, but still light enough to be reasonably portable.

The well-protected cones help too.

Chris
As a live sound engineer by profession.....I would use these Devs without hesitation for ANY genre of music you choose. They do exceptionally well with Jazz & Classical.... A good Tympani shot may scare you half to death.... Oh I would LOVE to rock a house party with 4 LFEs flexing the windows..... HOUSE MUSIC all night long.....


Depending on the gene, you MAY need to HP it a little higher to get more kick @ 35Hz plus.... These are solid performers all the way around...


Juju
gpmbc and Jan3 like this.

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
Sponsored Links
Advertisement
 
post #274 of 354 Old 02-14-2020, 01:46 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
Quote:
Originally Posted by BP1Fanatic View Post
With them, it's 40-50hz and up....NO musical content below those frequencies. I always come back with the lowest note on a piano is 27.5hz, why not build the enclosure to play that to that frequency.
Exactly.... I have done live Dubstep shows..... better have GOOD subs for that.....


Juju

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
post #275 of 354 Old 02-14-2020, 01:49 PM
AVS Forum Special Member
 
Red Five's Avatar
 
Join Date: Mar 2018
Location: Wisconsin
Posts: 1,622
Mentioned: 169 Post(s)
Tagged: 0 Thread(s)
Quoted: 1065 Post(s)
Liked: 902
I was at a concert last weekend and I had to pull out the RTA app to see what was going on. The SPL fell off a cliff at 47Hz, which was not a problem for most of the content, but once one of the hard rock groups took the stage and they drop tune heavily, it becomes immediately apparent the subs cannot move down there and all the power was lost. My low open B string is roughly 31.5Hz on my 5 string bass guitar, a 34Hz tune cabinet would be a fair compromise. It is easy to reach 95db sensitivity with that tune. To get all the concert effect TR the 50Hz to 110Hz range is pumped like crazy, you lose all sense of weight in the bass when you do that.
jujuman200 and Jan3 like this.

Stormbreaker | WI HT Meet Thread | The Devastator Index | Mini Devastator Build
You can always turn it down, but you can only turn it up so much (before you run out of power, excursion or structural integrity).
7.2.4 | A3070 | XLS 1502 | 3000DSP | 2x Aphex 124A | 2x Bic EV15 | 7x Bic FH6 LCR | 2x Bic FH65-B | Epson 5010e | 120" DIY AT Screen | 2x Mini Devastators
Red Five is online now  
post #276 of 354 Old 02-14-2020, 01:49 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
OK... back from the lab..... I just put 2 pillows in my LFE and you can tell how the tone tightens up even more.... I don't have my measurement rig with me at the moment but, I can tell you that it sounds damn good..... Pillow your boxes people.....




Juju
Jan3, Audiophile75 and Red Five like this.

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
post #277 of 354 Old 02-14-2020, 02:03 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
Quote:
Originally Posted by Red Five View Post
I was at a concert last weekend and I had to pull out the RTA app to see what was going on. The SPL fell off a cliff at 47Hz, which was not a problem for most of the content, but once one of the hard rock groups took the stage and they drop tune heavily, it becomes immediately apparent the subs cannot move down there and all the power was lost. My low open B string is roughly 31.5Hz on my 5 string bass guitar, a 34Hz tune cabinet would be a fair compromise. It is easy to reach 95db sensitivity with that tune. To get all the concert effect TR the 50Hz to 110Hz range is pumped like crazy, you lose all sense of weight in the bass when you do that.
You are absolutely correct sir in your observations..... "some" engineers are only concerned with VOLUME and not tonality as well... such a shame... Being that I used to do lots of World Music, you had to be ready for ANYTHING....
For example.. the African UDU drum can[depending on its size] get down into the upper 20's with serious authority...


Juju
asarose247 and Red Five like this.

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
post #278 of 354 Old 02-14-2020, 02:54 PM
AVS Forum Special Member
 
asarose247's Avatar
 
Join Date: Mar 2010
Location: DIY enabled in SoCal / OC
Posts: 4,552
Mentioned: 110 Post(s)
Tagged: 2 Thread(s)
Quoted: 1291 Post(s)
Liked: 1131
a not yet implemented sub . . .

hope it works
Attached Thumbnails
Click image for larger version

Name:	20181210_170057.jpg
Views:	75
Size:	2.07 MB
ID:	2684946  
BP1Fanatic and notfastenough like this.

DIY FAN Denon X4400 , ATI A 2000 for 7.4.6 SCATMOS Sammy 82" 4K/HDR
L/R: Fusion 15 V2 , C: 88 Special , SL/SR: 88 Special(V2) , RL/RR: F-3, TF/TR: Volt 6's TM: SLX, FH: F4Q4
SUBMAXIMUS V2, ,Submaximus V3,LOWARHORNCustom Dual Driver VBSS,2 x 6000DSP
asarose247 is online now  
post #279 of 354 Old 02-14-2020, 02:58 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
Quote:
Originally Posted by asarose247 View Post
a not yet implemented sub . . .

hope it works
It will work..... the question is how well for what you need..... What is the tune?


Juju

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
post #280 of 354 Old 02-14-2020, 04:07 PM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
Quote:
Originally Posted by a77cj7 View Post
Quick and dirty plugged port testing.


The HPF was disabled. The staggered pillows are still in the rear chamber.


To pursue this concept further, I’ll have to model it and see what HPF is needed. Also need to see how port velocity looks(I assume fine in this one), and how far power is limited due to excursion. I expect excursion to be an issue.

Chris

Awsome work on both this and the pillow testing, thanks so much for your continued effort on these never ending questions from us, LOL.

GREAT results with a couple of pillows, and the lower tune looks nice With standing pillows it should be even better

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #281 of 354 Old 02-14-2020, 05:09 PM
Senior Member
 
MTBDOC's Avatar
 
Join Date: Oct 2007
Posts: 218
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 71 Post(s)
Liked: 61
Yes, the plugged port looks AMAZING! So how hard would it be to simply modify it (the build) from the start for this response? That response looks UNREAL for movies with significant subsonic effects.


This just gets better and better ... I am truly astonished at what 4 of these $29 drivers can do!!!
MTBDOC is offline  
post #282 of 354 Old 02-14-2020, 06:07 PM
AVS Forum Special Member
 
Red Five's Avatar
 
Join Date: Mar 2018
Location: Wisconsin
Posts: 1,622
Mentioned: 169 Post(s)
Tagged: 0 Thread(s)
Quoted: 1065 Post(s)
Liked: 902
The Quad has a straight port, so an extension of the port will just add the rear assembly. I could do a lower tune 16Hz version later!

Stormbreaker | WI HT Meet Thread | The Devastator Index | Mini Devastator Build
You can always turn it down, but you can only turn it up so much (before you run out of power, excursion or structural integrity).
7.2.4 | A3070 | XLS 1502 | 3000DSP | 2x Aphex 124A | 2x Bic EV15 | 7x Bic FH6 LCR | 2x Bic FH65-B | Epson 5010e | 120" DIY AT Screen | 2x Mini Devastators

Last edited by Red Five; 02-14-2020 at 06:10 PM.
Red Five is online now  
post #283 of 354 Old 02-14-2020, 06:09 PM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
^^^^ YES, please !!

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #284 of 354 Old 02-14-2020, 06:27 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
EXPERIMENTAL Quad JBL Devastator Build

Quote:
Originally Posted by Red Five View Post
The Quad has a straight port, so an extension of the port will just add the rear assembly. I could do a lower tune 16Hz version later!


Don’t bother, IMHO.

I just ran the models on the plugged port, it’ll run fine as-is. We’re far enough out of the efficiency range of these JBL’s that it doesn’t go crazy.
Port plugs are easy enough to build, as I proved with my HST’s

Port tune is 15hz.
On 1000w, a 15hz 3rd order HPF keeps excursion under 15mm.
Port velocity is under 25m/s.

I’ll run the close-mic with the filters on.

Chris
jujuman200, Nalleh, Jan3 and 1 others like this.

Last edited by a77cj7; 02-14-2020 at 06:31 PM.
a77cj7 is online now  
post #285 of 354 Old 02-14-2020, 06:30 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
I’m also going to see if I can hear a difference with the pillows.

Any other tests/sweeps you guys want indoors before I put my theater back together?

Chris
Nalleh likes this.
a77cj7 is online now  
post #286 of 354 Old 02-14-2020, 06:34 PM
AVS Forum Special Member
 
gpmbc's Avatar
 
Join Date: Jun 2006
Location: AZ
Posts: 3,090
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 426 Post(s)
Liked: 317
You’ve really gone above and beyond Chris. Very cool 😎
a77cj7 likes this.
gpmbc is online now  
post #287 of 354 Old 02-14-2020, 06:58 PM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
Quote:
Originally Posted by a77cj7 View Post
I’m also going to see if I can hear a difference with the pillows.

Any other tests/sweeps you guys want indoors before I put my theater back together?

Chris
If you could place the pillows where it measured best: standing on each side, before you do that HPF test, that would be great ?

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #288 of 354 Old 02-14-2020, 07:05 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
Ok, here’s the close-mic with filters.



It looks like there’s no downside.

However, I am concerned about power compression.

Here was the compression shown on the ground-plane.

I would expect that to get worse at the lower port tune.

I can run ground-plane with a plugged port if I get a nice day. Not doing it in the snow.

I would like to see the pillow’s effects on the ground plane as well.

Chris
BP1Fanatic and Nalleh like this.
a77cj7 is online now  
post #289 of 354 Old 02-14-2020, 07:08 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
EXPERIMENTAL Quad JBL Devastator Build

Quote:
Originally Posted by Nalleh View Post
If you could place the pillows where it measured best: standing on each side, before you do that HPF test, that would be great ?


Nope, too late.

I had the same thought and moved them beforehand.

I am noticing a couple new dips on the close-mic lately. I’m assuming my hatch gasket is no longer making a perfect seal. I’ll replace the gasket when I make the vertical pillows permanent.

Chris
Nalleh likes this.
a77cj7 is online now  
post #290 of 354 Old 02-14-2020, 07:50 PM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
^^ Awsome, thanks.

Well, i guess the hatch has been opened a few times on this one, so a little leakage is to be expected, LOL.

IMO, this would be called a success, when thinking about how cheap those drivers are

Next, you should try playing the EOT intro and see how they handle that

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #291 of 354 Old 02-14-2020, 08:02 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
Quote:
Originally Posted by Nalleh View Post
^^ Awsome, thanks.



Well, i guess the hatch has been opened a few times on this one, so a little leakage is to be expected, LOL.



IMO, this would be called a success, when thinking about how cheap those drivers are



Next, you should try playing the EOT intro and see how they handle that


Yeah, hatch probably hasn’t been opened more than 30 times. Glad I have a good impact gun.

I’ve been considering this one a huge win for awhile now. I’ve just been trying to prove exactly how much, lol. This is definitely the value Devastator now.

EOT, yeah... these drivers have survived some brutal testing with no complaints. I probably shouldn’t torch them now just because.
Besides, thats what I have these for:

Chris
Nalleh likes this.
a77cj7 is online now  
post #292 of 354 Old 02-14-2020, 08:29 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
Quote:
Originally Posted by Red Five View Post
It looks like stapling pillows onto the side walls is a very viable option. Does it change the subjective sound signature at all? The Minis have a little ring to them, this has me thinking...


I gave it a shot, really hard to tell the difference when I have to pull it apart in-between. I didn’t pick up anything noticeable with the 80hz lpf.
When I turned off the lpf, it did sound cleaner up top. Also gained some chest-kick in the process, with the higher filter.

So yes, definitely try the pillows. But I can’t say it will clean up the sound any.

Chris
jujuman200 and Nalleh like this.
a77cj7 is online now  
post #293 of 354 Old 02-14-2020, 08:43 PM
Advanced Member
 
jujuman200's Avatar
 
Join Date: May 2008
Location: New Jersey
Posts: 556
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 274
Quote:
Originally Posted by a77cj7 View Post
I gave it a shot, really hard to tell the difference when I have to pull it apart in-between. I didn’t pick up anything noticeable with the 80hz lpf.
When I turned off the lpf, it did sound cleaner up top. Also gained some chest-kick in the process, with the higher filter.

So yes, definitely try the pillows. But I can’t say it will clean up the sound any.

Chris
With the LFE.... I can say that it kills that slight ring that they have...definitely try the pillows....


Juju
Nalleh likes this.

Sub List: 1- Red Five Mini Devastator 18" w/460HO, 1- Red Five Devastator LFE 21", 1- BOSS platform [The Hideaway Theater], 1- 21" "Marty" tuned to 20Hz, 1- 18" "Marty" tuned to 17Hz
Wish List: Anthology http://www.speakerdesignworks.com/Anthology_1.html

jujuman200 is online now  
post #294 of 354 Old 02-14-2020, 10:51 PM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
This is just me being stubborn, but the alternative i mentioned earlier would be interesting to try:



My thought was to break up the resonance but not disturb the airflow.

I mean since the different pillow placements already tested had such noticable impact
Attached Thumbnails
Click image for larger version

Name:	63FF77B3-669B-4D73-A2E3-02056F7F497E.jpeg
Views:	118
Size:	45.5 KB
ID:	2685062  

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #295 of 354 Old 02-14-2020, 10:55 PM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
EXPERIMENTAL Quad JBL Devastator Build

Quote:
Originally Posted by Nalleh View Post
This is just me being stubborn, but the alternative i mentioned earlier would be interesting to try:







My thought was to break up the resonance but not disturb the airflow.



I mean since the different pillow placements already tested had such noticable impact


I played with that config briefly. Pillows don’t fit right in the cab.

I’m not sure what you hope to gain over the two vertical, which completely killed the resonance while not hurting the low end any more than a single.

I did place them at different levels, facing the other direction, but it took more off the low end than vertical.


Chris
a77cj7 is online now  
post #296 of 354 Old 02-15-2020, 09:03 AM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
^ Yes, but that could be because the way you did it there, the lower pillow blocks the port. Putting the pillows staggered front to back would not do that. But yeah, your pillows might be to big

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #297 of 354 Old 02-15-2020, 09:17 AM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
Quote:
Originally Posted by Nalleh View Post
^ Yes, but that could be because the way you did it there, the lower pillow blocks the port. Putting the pillows staggered front to back would not do that. But yeah, your pillows might be to big


There is bracing closer to the port mouth than the bottom pillow.

General rule-of-thumb is to keep obstructions at least port-height from the end of the port, here is at least 3 or 4 times that.

Not so much to big, but completely wrong shape.

Chris
a77cj7 is online now  
post #298 of 354 Old 02-15-2020, 09:56 AM
AVS Forum Special Member
 
Nalleh's Avatar
 
Join Date: Aug 2014
Location: Norway
Posts: 4,310
Mentioned: 399 Post(s)
Tagged: 0 Thread(s)
Quoted: 2944 Post(s)
Liked: 4084
^^ Ok, noted I’ll leave it at that then, carry on

Dual AVR 13.1.8 SWAtmos - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 12xJBL 12" w/6xSLAPS M12 downfiring VNF - 3x2 stacked Crowson MA - 4xBK-LFE Dual TR Sleds- 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XB1X - ATV4K - Vertex2 - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
>>>>Nalleh’s HT<<<<
Nalleh is online now  
post #299 of 354 Old 02-15-2020, 10:12 AM
Senior Member
 
MTBDOC's Avatar
 
Join Date: Oct 2007
Posts: 218
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 71 Post(s)
Liked: 61
Although it isn't a huge change, I had played around on WinISD @ 1200w looking at ported & sealed configurations. The longer port would allow a bit more juice, would it not?


I really can't make too much sense out of all this, however, as I have yet to grasp how to actually model these slotted ports in WinISD (yes, I have tried to digest the threads such as this: https://www.avsforum.com/forum/155-d...so-simple.html). The correction factor doesn't agree with what the Marty subs utilize.


Anyway, for the umpteenth time, Chris thank you for your STELLAR efforts in this project! When the final details are published (cut & build sheets) that an inexperienced builder like me can follow, I am going to build at least one of these. The performance is simply astonishing!
MTBDOC is offline  
post #300 of 354 Old 02-15-2020, 11:00 AM - Thread Starter
AVS Forum Special Member
 
a77cj7's Avatar
 
Join Date: Aug 2019
Location: Sturgis, SD
Posts: 1,180
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked: 681
EXPERIMENTAL Quad JBL Devastator Build

Quote:
Originally Posted by MTBDOC View Post
Although it isn't a huge change, I had played around on WinISD @ 1200w looking at ported & sealed configurations. The longer port would allow a bit more juice, would it not?


I really can't make too much sense out of all this, however, as I have yet to grasp how to actually model these slotted ports in WinISD (yes, I have tried to digest the threads such as this: https://www.avsforum.com/forum/155-d...so-simple.html). The correction factor doesn't agree with what the Marty subs utilize.


Anyway, for the umpteenth time, Chris thank you for your STELLAR efforts in this project! When the final details are published (cut & build sheets) that an inexperienced builder like me can follow, I am going to build at least one of these. The performance is simply astonishing!

The modeling programs don’t take port velocity and port compression into account, so the models should look very similar. The longer port will have less rear-chamber volume, which may SLIGHTLY increase power handling and SLIGHTLY reduce low end output, but not by enough to matter.

Real world, the smaller port will experience more port compression and be at a higher risk of port noise. Under 25m/s, I wouldn’t be concerned about either.

Running the shorter port also gives you both tune options.

I really don’t use winisd much any more. I have found hornresp to be closer on port tune. Winisd is still within a few hz at worst though.
I’m pretty sure the end correction is nonfunctional in winisd, don’t bother with that one.

I believe this one is finalized on my end, at least for build purposes. I’ll continue to work with Josh to finish up the measurements.
I’m waiting for him to review the latest ground-plane before I update the main posts.

Getting all the details and cutlists posted on the Index is in John’s court now. @Red Five
Only special instructions on this one will be wiring and pillows.

Chris
jujuman200 likes this.
a77cj7 is online now  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off