Jump to content
Sign in to follow this  
lukeamdman

(8) Ported Incriminator Audio Judge 21" build

Recommended Posts

One half way down 7 to go? :D

 

I forget what are you powering these with? 2x SP-12000's?

  • Like 1

Share this post


Link to post
Share on other sites

I know it's a way off but an impedance curve would be nice whenever you get around to it. That'll tell us roughly where the tune ended up and how bad the vent resonance is. I bet the tune comes in lower than the sim.

Share this post


Link to post
Share on other sites

I know it's a way off but an impedance curve would be nice whenever you get around to it. That'll tell us roughly where the tune ended up and how bad the vent resonance is. I bet the tune comes in lower than the sim.

 

That's what I'm doing first whenever I drop the driver in tonight or tomorrow.  

 

WinISD said the port length should be 64" for a 15hz tune in 11.72cu.ft, but I made the port about 55" instead based on some feedback from LTD and notnyt.  

Share this post


Link to post
Share on other sites

Looking good man. Really like that round over. How are you getting this downstairs?

 

I had one of my brothers over to help me out.  Took a nice chunk out of the drywall getting it down there too!  Oops.  

Share this post


Link to post
Share on other sites

I know it's a way off but an impedance curve would be nice whenever you get around to it. That'll tell us roughly where the tune ended up and how bad the vent resonance is. I bet the tune comes in lower than the sim.

 

Here you go Josh:

 

15hz%20impedance_zpsrqf9drhq.jpg

 

Min is 13.8hz (4.5ohm), max is 38hz.  

 

Two of these will be paralleled to a channel of the SP2-12K.  

Share this post


Link to post
Share on other sites

Those are 1.5" ports on my mains:

 

20170128_184517_zpsj291enfh.jpg

 

20170128_211721_zpshcakugbu.jpg

 

20170128_211729_zpspye0n8qw.jpg

 

 

 

 
I was comparing various music tracks and movie clips to one of the dual sealed boxes:
 
20170128_224207_zpshfyw5uqu.jpg
 
 
Looks like that 90deg turn and the port proximity to the side wall lowered the tune by 1hz. Oh darn  :D
 
No port noise to speak of, and 12-20hz one of these is louder and cleaner than one of the dual sealed boxes. Definitely the reduction in harmonic distortion in that range I was looking for.

Share this post


Link to post
Share on other sites

I had a few minutes to run some sweeps. This is with no EQ or XO (receiver set to the max of 250hz), and I did lower the dual-opposed sealed sub by 3db since the DCR is half (1.5ohm vs. 3.0ohm) because two drivers are paralleled. The sealed still has an advantage though since it has twice the Sd but you get the idea and this isn't completely apples to apples anyway since they're not positioned the same in the room:

 

20170128_224207_zpshfyw5uqu.jpg

 

Sealed%20vs%20Ported_zpsxhatzls4.jpg

 

 

 

Ported vs. ported with a 14hz BW3 HPF:

 

Ported%20with%20HPF_zps4rbfkd1a.jpg

Share this post


Link to post
Share on other sites

Looks like your tuning came in at 14Hz or so from the impedance curve. Nice. What are you setting a HPF at 14Hz with? Minidsp?

Share this post


Link to post
Share on other sites

Looks like your tuning came in at 14Hz or so from the impedance curve. Nice. What are you setting a HPF at 14Hz with? Minidsp?

 

Yes, a MiniDSP 10x10HD.  

Share this post


Link to post
Share on other sites

Well done! I'm surprised it worked as well as it did. Good work. :)

 

So now.... seven more?

 

*shudders*

 

What I assembled over 4 days before (basically everything but the baffles), I'm going to assemble in a single evening, so that should cut the build time in half at only 3 days per box.  

Share this post


Link to post
Share on other sites

Do you have an umbrella policy on your house that covers 'structural damage from sound system' and/or 'Acts Attributed to the Bass Gods'?

 

JSS

  • Like 1

Share this post


Link to post
Share on other sites

The resonance looks a bit high Q, but that could just be a room thing too.  I'd probably want to try to knock it down a bit with a PEQ.

Share this post


Link to post
Share on other sites

The resonance looks a bit high Q, but that could just be a room thing too. I'd probably want to try to knock it down a bit with a PEQ.

These with have a 32hz BW3 LPF with othorns taking over above that.

Share this post


Link to post
Share on other sites
Last night I removed the DO sealed cabinet and pushed the ported cab closer to the back wall and it mostly fixed that dip between 50-70hz. 

 

With just one of these I was hitting 128-129db during the 17hz note of Bass I Love You, and 121-122db during the 14hz note of Curtain Shaker. Still no port noise.

 

+18db with 7 more! 

 

Just because it'll bug me if I don't, I'm going to do a 1/2" round over on the ports and also add a tiny bit of bracing.

Share this post


Link to post
Share on other sites

Are you firing the ports and drivers forwards so you can get that standing in front of a box fan wind effect?

 

Plug 2 ports on each cab for the sub 10Hz tuning? :lol:

Share this post


Link to post
Share on other sites

Are you firing the ports and drivers forwards so you can get that standing in front of a box fan wind effect?

 

Plug 2 ports on each cab for the sub 10Hz tuning? :lol:

 

lol no.  They'll be firing at the side walls.  

 

It's going to be a tight fit.  They'll be 2" from the back wall and only 10" from the side walls, but it's the only way to make it work.  

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×