Eq'ing 16 subs: Can it be done? - AVS | Home Theater Discussions And Reviews
Forum Jump: 
 2Likes
Reply
 
Thread Tools
post #1 of 34 Old 01-29-2015, 06:18 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Eq'ing 16 subs: Can it be done?

2 of my LMS'es aren't summing correctly below 7hz now that the 21's are powered up.
I believe it is a phase and timing issue, I think I might be able to correct it by physically inverting the wires... but I don't currently have discrete DSP channels for the 21's so I might just have to live with the lack of timing for now.




But overall I didn't gain any SPL below 5hz, I believe that is because the DCX rolls off at 8hz, so shelves and room-gain are the only thing keeping it alive.
That and, I think the 21's are just simply too inefficient at 2-4hz to make a big difference.
Also, my room acts like a 5hz sealed box... because that's basically what it is. So that doesn't help either.
When I open the theater doors I gain 10db @ 1-5hz.
I don't really care about 1-4hz, I just thought I'd mention it...

Up until 8 drivers the SPL was summing perfectly in 6db steps, and then between 8 and 14, a brick wall. That's as far as I got.

Ya know, it would be great if TC stuck around so that I wouldn't have to mix and match different brands.
The various vendors keep going bankrupt before I can buy an array of drivers.
Adire, Exodus and then TC, it's so sad!

I haven't EQ'ed anything yet, this is RAW response @ LP by the way.



My room has a nasty 90hz dip, I've known that for a few years now.



The 21's are in Pi space, the LMS are in Half-Pi space, at roughly the same overall distance.

All the subs in Half-Pi space are showing a 28hz room peak.
Above 60hz my room descends into room-mode chaos.
Attached Thumbnails
Click image for larger version

Name:	FR Sweep.jpg
Views:	299
Size:	190.0 KB
ID:	509586   Click image for larger version

Name:	14subs.jpg
Views:	294
Size:	141.2 KB
ID:	509634   Click image for larger version

Name:	4subs.jpg
Views:	293
Size:	139.4 KB
ID:	509642  
superfrog01 likes this.

Last edited by BassThatHz; 01-29-2015 at 06:53 AM.
BassThatHz is online now  
Sponsored Links
Advertisement
 
post #2 of 34 Old 01-29-2015, 07:03 AM
Senior Member
 
Bombelman's Avatar
 
Join Date: Nov 2013
Location: Paramaribo
Posts: 256
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 41
apple pie ?
Bombelman is online now  
post #3 of 34 Old 01-29-2015, 02:02 PM
AVS Special Member
 
Luke Kamp's Avatar
 
Join Date: Aug 2010
Location: Kansas City
Posts: 1,252
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Liked: 130
I will throw out somethings I have seen over time.

"We usually don't recommend more than four subwoofers as it's not only overkill but can cause more problems than it solves, especially if the subs are placed in non optimal locations. For instances where more output is needed, you can exceed the four sub rule as long as you limit your placements to up to four locations. So in such cases you can stack subwoofers on top of each other in the locations that are best suited for optimal performance."

http://www.audioholics.com/subwoofer...-calibration-1

Todd Welti-
The conclusion I came to was that two subwoofers give you about 90% of the performance that is possible, and that four take you about as far as you can reasonably expect to go. Anything more than four is not going to get you much in the general sense -- and these are general conclusions.

http://www.htguide.com/forum/showthr...subs-is-enough


I have never read this, but imagine it would be a good read. Todd Welti's How Many Subwoofers are Enough?

http://www.aes.org/e-lib/browse.cfm?elib=11355

You could try stacking them to the ceiling.

http://bossobass.com/Bossobass.com/Technical.html

I haven't seen anyone say more than four locations as being really beneficial. Have you tried grouping your subs in locations instead of spreading them out? How many seats are you trying to smooth? It may be you could find a more efficient placement in grouping your subs for a good seat or two instead of throwing more power at the drivers with them spread around the room.

"Above 60hz my room descends into room-mode chaos."
I think I have brought this up before, but from the data I have seen acoustic foam isn't the best tool for the job in the 60hz to 300hz region. Also could experiment around with using some flanking subs as discussed by Parham here.

http://audioroundtable.com/forum/ind...msg&goto=66914

Another AES paper by Welti, The Effect of Whole-Body Vibration on Preferred Bass Equalization in Automotive Audio Systems
"The results reveal that the presence of whole-body vibration can reduce the preferred level of bass equalization by as much as 3 dB depending on the program, the level of vibration, and the individual listener. Evaluations of a virtualized automotive audio system were judged to sound closer to the actual system when the simulated vibrations were included."

In experimenting with nearfield subs and a shaker system with a riser vs just subs up front on concrete, I have found similar results that the additional feel actually had me drop the lfe out a little bit in balancing the bass with the system. Maybe try out some of the highly regarded Crowson transducers or some nearfield subs.

With the amount of subs and equipment your experimenting is pretty limitless. No one can doubt the level of passion you have for the hobby. Get to experimenting and have fun.

Good Luck
derrickdj1 likes this.

Last edited by Luke Kamp; 01-29-2015 at 02:08 PM.
Luke Kamp is offline  
post #4 of 34 Old 01-30-2015, 08:30 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
I haven't read any of those links yet, but there is one thing I'd like to try.
I have heard of putting the sub in the golden seat and doing a subwoofer crawl.

Except for instead of using my ears, I'm gonna use the UMIK. (Thank god I bought those 50ft cat5 to usb converters, that gives me a 60ft USB cable.)

Because let's face it, moving a UMIK around is far lighter than moving 21's, and is also better than using your eardrums to find the sweet spot.


If I can get the golden seat to be golden, then the other seats can suffer. (The variation between seats is almost nothing in my case, only one small row.)


I will search from the dwarf meadows to the eye of sauron, both high and low.
Attached Thumbnails
Click image for larger version

Name:	h0cuz.jpg
Views:	161
Size:	45.3 KB
ID:	511833   Click image for larger version

Name:	SANY0059.JPG
Views:	160
Size:	305.6 KB
ID:	511849  
BassThatHz is online now  
post #5 of 34 Old 01-30-2015, 09:02 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Interdasting!

Well this is gonna take forever!!! LOL

These are all of the positions I have available to me.
(A few aren't very practical but I thought I'd include them anyways.)



Attached Thumbnails
Click image for larger version

Name:	fr graph 2.jpg
Views:	153
Size:	264.9 KB
ID:	512041   Click image for larger version

Name:	fr graph 1.jpg
Views:	156
Size:	211.9 KB
ID:	512049   Click image for larger version

Name:	fr graph.jpg
Views:	153
Size:	281.8 KB
ID:	512057  
BassThatHz is online now  
post #6 of 34 Old 01-30-2015, 09:09 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Let's look at nearfield first:



nuke skull prime is the loudest. This is the driver firing directly into my skull and point blank range.

But endtable is the most-best IMO of the NF's. (I'll have to research that position more.)
Attached Thumbnails
Click image for larger version

Name:	fr graph3.jpg
Views:	150
Size:	223.2 KB
ID:	512081  
BassThatHz is online now  
post #7 of 34 Old 01-30-2015, 09:14 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Side walls:


Looks like by spinning the subs 180 I can make them slightly better (in theory).
Attached Thumbnails
Click image for larger version

Name:	side walls.jpg
Views:	148
Size:	196.5 KB
ID:	512153  
BassThatHz is online now  
post #8 of 34 Old 01-30-2015, 09:19 AM
Member
 
AV Hack's Avatar
 
Join Date: Jan 2015
Location: Greater Bay Area, CA USA
Posts: 127
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Liked: 19
This is really interesting.
I have seen several schools of thought on multiple subwoofers over the years. This one is one useful link:
http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White%20Papers/multsubs.pdf

I am very curious as to how this all pans out.
Good testing.

Working on the next one...
AV Hack is online now  
post #9 of 34 Old 01-30-2015, 09:20 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
I think this rules out putting them in the front (however it would be co-located so more research is still needed here.)

Top is impractical (that's stacked on top of my LMS's).
Attached Thumbnails
Click image for larger version

Name:	front.jpg
Views:	143
Size:	185.1 KB
ID:	512193  

Last edited by BassThatHz; 01-30-2015 at 11:35 AM.
BassThatHz is online now  
post #10 of 34 Old 01-30-2015, 09:22 AM
AVS Special Member
 
derrickdj1's Avatar
 
Join Date: Sep 2011
Posts: 1,726
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 179 Post(s)
Liked: 160
EQ'ing the subs in two to four groups may work.
derrickdj1 is online now  
post #11 of 34 Old 01-30-2015, 09:25 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Rear of room:


Again, no better than the original position.
However... I must see the integration interactions before ruling these out.
Attached Thumbnails
Click image for larger version

Name:	rear.jpg
Views:	134
Size:	209.8 KB
ID:	512201  
BassThatHz is online now  
post #12 of 34 Old 01-30-2015, 09:33 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Based on positioning alone, here are the top-picks thus far:


Nearfield isn't looking so bad. Especially nuke-prime
But neither was my original position all that bad (from a single-sub positioning-perspective relative to the golden seat.)
Attached Thumbnails
Click image for larger version

Name:	top picks.jpg
Views:	134
Size:	206.3 KB
ID:	512233  
BassThatHz is online now  
post #13 of 34 Old 01-30-2015, 09:43 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
I'm going to put the sub back to its original position for time being.

Now it is time to look at integrations, in pairs, in the best positions!
If I can get my 6 biggest elite-subs playing nice with each other, the rest of the other 10 smaller/weaker subwoofers can just suffer, with some help from brute-force DSP.

After that is over with: I'll probably try pair-integrations with nuke-prime... just for pure giggles. Why not?

Last edited by BassThatHz; 01-30-2015 at 09:51 AM.
BassThatHz is online now  
post #14 of 34 Old 01-30-2015, 09:53 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Quote:
Originally Posted by Bombelman View Post
apple pie ?


mmmm... apple pie! LOL
BassThatHz is online now  
post #15 of 34 Old 01-30-2015, 10:05 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
2 21's in-phase in original positions:


So which one is better? LOL

Ok, so we have established this much...
Attached Thumbnails
Click image for larger version

Name:	out of phase.jpg
Views:	122
Size:	169.7 KB
ID:	512281  
BassThatHz is online now  
post #16 of 34 Old 01-30-2015, 10:21 AM
AVS Addicted Member
 
Mfusick's Avatar
 
Join Date: Aug 2002
Location: Western MA
Posts: 25,432
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 249 Post(s)
Liked: 1212
How low , and how loud, and how accurate can you measure?

-

"Too much is almost enough. Anything in life worth doing is worth overdoing. Moderation is for cowards."
Mfusick is online now  
post #17 of 34 Old 01-30-2015, 10:24 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Below 35hz it looks "ok". This is with the existing delays I already had. Except unlike yesterday I have inverted the coils on my 21's so that they are (potentially) in-phase with the 4 LMS's.


63hz is exactly the width of my room at the speed of sound, which makes sense since I run my subs stereoscopically width-wise.
Attached Thumbnails
Click image for larger version

Name:	pairs1.jpg
Views:	116
Size:	183.8 KB
ID:	512305  

Last edited by BassThatHz; 01-30-2015 at 11:41 AM.
BassThatHz is online now  
post #18 of 34 Old 01-30-2015, 10:31 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
With the quad set out of phase I gain 10db between 30 to 77hz. So there could be a phase or timing issue here.


The phase of the LMS's to each-other are correct.
Attached Thumbnails
Click image for larger version

Name:	pairs2.jpg
Views:	112
Size:	196.8 KB
ID:	512353   Click image for larger version

Name:	out of phase2.jpg
Views:	112
Size:	170.3 KB
ID:	512369  
BassThatHz is online now  
post #19 of 34 Old 01-30-2015, 10:44 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
A 2ft delay between the 4 LMS's gives as-good-as a summation as I'm going to get (until I upgrade the amplifiers at least). [I lose 4db @ 5hz because of it.]


Not sure what is going on at 85hz, that is 13ft. Half-cycle of depth mode reflection maybe? (Nothing I can do about that!)
Attached Thumbnails
Click image for larger version

Name:	delay1.jpg
Views:	107
Size:	197.0 KB
ID:	512417   Click image for larger version

Name:	LMS.jpg
Views:	89
Size:	166.8 KB
ID:	512721  

Last edited by BassThatHz; 01-30-2015 at 11:48 AM.
BassThatHz is online now  
post #20 of 34 Old 01-30-2015, 10:52 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Now I'm attempting to integrate 3 sets of pairs. LOL!!!

This is where things get complicated, and you can see the issue I was describing yesterday.


I think some of this is caused by the difference in amplifiers.
I'm going to re-wire my FP14000 and see if I can't get the subwoofers to play nice together, or nicer...
Attached Thumbnails
Click image for larger version

Name:	delay2.jpg
Views:	106
Size:	205.4 KB
ID:	512513  

Last edited by BassThatHz; 01-30-2015 at 10:56 AM.
BassThatHz is online now  
post #21 of 34 Old 01-30-2015, 10:59 AM
AVS Special Member
 
GreySkies's Avatar
 
Join Date: Oct 2003
Location: Formerly Chicagoland, now Doylestown, PA
Posts: 2,621
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Liked: 51
Quote:
Originally Posted by BassThatHz View Post
This is the driver firing directly into my skull and point blank range.
It's sentences like this that made me love this forum.

You know the next step to this is "I had the driver surgically implanted, and now I plug myself in before the movie starts."
GreySkies is offline  
post #22 of 34 Old 01-30-2015, 11:23 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Quote:
Originally Posted by Mfusick View Post
How low , and how loud, and how accurate can you measure?
A UMIK-1 can do +-2db from 5hz to 25,000hz between 30db to 130db, which is good enough for almost everyone.

I can measure up to 180-190db from 2hz to 250hz within 1/10th of a db.
Between 10hz to 100hz up to 180-190db, within 1/100th of a db.

I'm sure I could measure down to 1hz at up to 130db with the UMIK if I put my mind to it, how accurately I'm not sure...

Good luck at generating 180db @ 2hz though

I've seen the UMIK do -30db @ 10khz once and 0db @ 50hz and 22db @ 2hz, how accurate that figure is I don't know... (if you are in to measuring really quiet things.)

Last edited by BassThatHz; 01-30-2015 at 11:28 AM.
BassThatHz is online now  
post #23 of 34 Old 01-30-2015, 11:56 AM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Ok, what? I've lost 5db just by re-wiring the FP14000.

What is the FP10kQ clone doing wrong or differently than my itech 8000?


Wired in mono maybe?

edit:
Nope it's stereo and the phase it correct by the looks of it.
I think the itech might have a signal booster that the clone lacks. (because the 10kQ is not built right I assume or as microsoft would say: "intentional feature" LOL how rich!)
Not a big deal, I can just crank my FP14000 5db louder, but before I do that I have to ensure it won't affect my gains and thus clipping point; otherwise bad things could happen...

edit:
The rewiring clone amps has change the frequency response. (For the better I think... we will see!)
Attached Thumbnails
Click image for larger version

Name:	clone.jpg
Views:	89
Size:	176.6 KB
ID:	512729   Click image for larger version

Name:	rewired.jpg
Views:	83
Size:	179.2 KB
ID:	512753  

Last edited by BassThatHz; 01-30-2015 at 12:16 PM.
BassThatHz is online now  
post #24 of 34 Old 01-30-2015, 12:10 PM
Senior Member
 
mlah384's Avatar
 
Join Date: Jan 2010
Location: Mississippi
Posts: 438
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 225 Post(s)
Liked: 77
Can the amp even do 5hz effectively? Where does the amp start to struggle? Don't most amps have a limit? Like 5hz-20k hz, etc?
mlah384 is offline  
post #25 of 34 Old 01-30-2015, 12:25 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Ok, I cranked up the FP14000 5db to compensate for the wiring difference. (I will worry about the gain structure later, it's not important right now and it will just slow me down.)
Attached Thumbnails
Click image for larger version

Name:	5db.jpg
Views:	78
Size:	178.1 KB
ID:	512777  
BassThatHz is online now  
post #26 of 34 Old 01-30-2015, 12:30 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Quote:
Originally Posted by mlah384 View Post
Can the amp even do 5hz effectively? Where does the amp start to struggle? Don't most amps have a limit? Like 5hz-20k hz, etc?
Well I'm not sure, NotNyt's tests should answer that.
But I do notice a drop in excursion and what appears to be Vout or Vin at 5hz, which could just be my DCX, not the clone.
I tended to bypass by DCX to see if I gain SPL, excursion and Vout/Vin below 5hz (eventually), but that's not a permanent solution for me, that's just a party-trick at best.
BassThatHz is online now  
post #27 of 34 Old 01-30-2015, 12:42 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
My intuition was correct.
Rewiring the amps definitely made an improvement with these 4 subs.
The FR of the 21's hasn't changed nor the LMS, so I can only assume that the 63hz dip was caused by the itech's daisy booster's phase shift.

See this is why you should never mix amplifiers. LOL! (Not my fault though, go complain to Crown.)

I never would have guessed that in a million years.
Attached Thumbnails
Click image for larger version

Name:	signal.jpg
Views:	68
Size:	177.6 KB
ID:	512809  

Last edited by BassThatHz; 01-30-2015 at 12:45 PM.
BassThatHz is online now  
post #28 of 34 Old 01-30-2015, 12:52 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Just by lifting the subwoofers up 2ft or rewiring the amp I get 4 different responses. That's crazy if you ask me!!!


Both like-pair combinations have improved:




So I think I have made the right choice here.

I believe I have now solved all phase issues below 90hz. That is AWESOME!

But we aren't out of the woods just yet player-boy, now let's see how the 6 subs sum together!!! (Please no more surprises you silly woofers!!! LOL)
Attached Thumbnails
Click image for larger version

Name:	amps1.jpg
Views:	67
Size:	207.4 KB
ID:	512865   Click image for larger version

Name:	amp2.jpg
Views:	65
Size:	183.5 KB
ID:	512873  

Last edited by BassThatHz; 01-30-2015 at 01:01 PM.
BassThatHz is online now  
post #29 of 34 Old 01-30-2015, 01:07 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
Ok I have gained SPL. The summation seems to be working. Except for a small area near 5.5hz, it didn't sum well there. (I blame the amplifiers for that one!)


But the question is: Has it improved from yesterday?
Attached Thumbnails
Click image for larger version

Name:	6 subs.jpg
Views:	63
Size:	205.5 KB
ID:	512921  
BassThatHz is online now  
post #30 of 34 Old 01-30-2015, 01:34 PM - Thread Starter
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,593
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 500 Post(s)
Liked: 489
The answer is Yes. I have gained up-to 6db!
(50hz is most notable).


I haven't even moved the subwoofers yet (still in original positions), all I've done is debug the amplifier differences and attempted to resolve them.

I think it is time to go for it and try the skull-nuke-prime location now, see what I actually gain (or lose) by moving even just 1 of the 2 21's to the back of my skull. LOL!
Attached Thumbnails
Click image for larger version

Name:	today.jpg
Views:	52
Size:	161.0 KB
ID:	512969  
BassThatHz is online now  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs



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