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RoboKlipsch

Roboklipsch's DIYSG 4cft ported build using Legacy EF 15" Driver

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10 hours ago, CECAA850 said:

Not much to add but that's why I always dry for my drivers before the baffle plate is ever installed. 

I'll take credit for doing the best i knew how to do -- before built, I took the two baffles and placed them on the carpeted floor.  I placed the driver in the middle, and pulled up the two baffles to see if they fit.  They seemed to at the time.  I couldn't tell you for sure if they should have fit, but just didn't, or if the driver was too big for the cutout.  The driver was not part of the original design, obviously.  I had written to Erich and he responded, he thought it would fit but wasn't sure.  

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Update:  Starting up the subs, the old saying, "better to be lucky than good" came to mind.  I had thought to move the amps to the back of the room, where the bigger subs would go.  I plugged them in, and.....HUMMMMMM.  And having turned off Audyssey, it didn't seem I had any sound.  Hmm this doesn't seem right.  

 

After about an hour of fiddling around with the amp gains,  I realized Audyssey being off meant that the Audyssey Dynamic EQ was also off, and listening at low volume there might not be much to hear.  I put it back on, and heard the bass and the hum.

 

I remembered enough discussions of power sources and conditioners to think that was likely it.  So was adding a 2ohm setup causing a problem?   I tried another outlet, and it seemed to be the same.  Tried a surge protector in between, still there.  I took an extension cord and extended all the way back to where I had it plugged in before -- no hum.

 

Another minor heart attack averted :)  The outlet i was using obviously was fine, while the other two (out of maybe 7 in the room) hummed.  I had been lucky in my earlier setup, somehow using a good outlet right off the bat.

 

Placement was pretty awesome imo.  I will post a schematic of the room which I had sketched before in case anybody has an L-shaped room and is wondering about the acoustics.   I went with a modified 4 corners layout following the amazing and somehow rare study of multiple subwoofer placement.  There are millions of studies out there and somehow only a few serious studies of proper placement backed by actual testing.  

 

Here is the link.   Anybody with a subwoofer should consider this required reading.  An amazing 20 minutes whether you have 1 sub or 20.  

https://www.harman.com/sites/default/files/white-paper/12/11/2015 - 06%3A12/files/multsubs.pdf

 

I have a lot more to share and details and steps I followed getting them properly setup, matched, calibrated and then EQd.  I used DDJ's subwoofer setup guide as...a guide :) and then made a few tweaks of my own using Audyssey that may provide a path for everyone to follow that is even easier and more accurate for those using an autocalibration system.  

 

Are the new subs great?  Does 4 subs sound better than 2?  Are the graphs tighter with less variance?  Are they polished and ready for their centerfold shots :lol: ?

 

Stay tuned I've got a lot more to share!  

 

 

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I would love to hear some feed back to the setup method for the sub and mains. Auddysee may differ in how it works with the method.  That, I don't know since I have not used it for 5 or 6 years.  I setup the sub and mains, then run MCACC, then tweak things with a bit of PEQ on the low end and then run Manual MCACC to correct things that the PEQ may have altered in the standing wave, phase and time domain. This is when I run the 3 point calibration (Manual MCACC) or with Audysee, the 8 point can now be ran.  This should take full advantage of the avr's DSP.

 

Let's see some graphs Rob.:)

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The hum is a 60 cycle ground loop hum.  It happens some times with external amps and having a couple different paths to ground in the same system.

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The boxes look great! Can't wait to hear what you think of them once you get them going. I had a nasty humm through out my speakers and subs. The way I fixed them and there's many way to do it... was I daisy chained a 14 gauge wire to each of my audio components in my rack. I stripped the end of the wire installed a spade fitting on the end of it and screwed it into a screw on each sub amp going all the way up to both surge protectors. As soon as I did that the humm was completely gone. Maybe try that. I had thread on Avsforum with pictures on how I did.51f24f0946ec82f744ba2f286d1669e1.jpge06d7706c565ec16548db175e42b22c2.jpg

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I had that problem but, maybe I didn't daisy chain enough componets.  That is the nice things about having a rack that holds everything in the same area.

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3 hours ago, eng-399 said:

Have you had a chance to listen to the subs yet.

Yes, we have all been waiting for an update.

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Update to come!  Sorry for the delay.  I knew enough not to write too much too early, and I'm darn glad I did.

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Update!

 

I apologize for the delay.  There is no drama or anything bad that happened with the new subs.  Quite the contrary!  

 

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

When I first picked up my RSW-15 in early spring of this year, it was a very dramatic moment.  Having had Bose and a few lower end subs including a Klipsch R10SW, the RSW was mindblowing.  Suddenly I could hear down much lower than before, movies, shows, games suddenly took on a whole new sound and experience.  It was really impressive.  Not transcendent, but a huge leap forward.  I remember well the first time I put on Gravity, one of my favorite test Blu-Rays.  Suddenly there were sounds I never heard before, they were bold, and it was incredible.  At the time Far Cry Primal had been released (a PS4 video game) and the intro to that game has some major deep tribal drums....WOW!  Just amazing.  A few friends came over, heard it, and were actually jumping out of their chairs at it.  Loaded in a corner, the RSW was quite a thing.  I wish I had the testing equipment back then to test it loaded in the corner, but alas I did not.  

 

When I sold the RSW, and picked up a couple of 8cft net Ultimax ported 18's from one of the coolest members on this site, I entered into the world of incredible bass.  Loud, commanding, it ripped the doors off the RSW and made me never look back.  

 

Moving to 2 subs was a challenge.  It was no longer one sub to be calibrated to the mains, but 2.  I spent hours, days really, testing, looking for the right spots, testing again...and again.  Anybody who has spent hours testing out positions only to find they are not better than the last...the quest for the right spots, so to speak...understands :)

 

So there was added complexity.  Lots of REW graphs, lots of UMIK testing, it was really a fun and not difficult...but long process.  I literally tested every spot in my room.  I have saved graphs of exactly what one will do in any spot along a wall.   My room is an L-shaped room, so most fundamentals of placement do not fully apply.  I spent hours and hours tweaking, getting the delays right, trying out different PEQ curves.

 

When I was done, with 2 subs, my response was this:  

 

 

Left Seat.jpg

Center Seat.jpg

Right Seat.jpg

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Update continued:

 

If my goal at the time was simply to have the MLP flat, that would have been easy and could have been done with many different positions within the room.  But with an irregular shaped room and 3 (5 actually) seating positions being used, it was incredibly challenging.  Move a sub a bit, it may improve response at one position.  But it may make it worse at others.  So there is a long, iterative process of trial and error to find where the best possible positions in the room are.  I found them.  One was behind the left seat of the couch, about 4 feet back.  The other was in the front right of the soundstage, inside of the right speaker.  The curves in the last post were what I could achieve in those positions, with a LOT of EQ.  I am lucky enough to have a relatively small room, and I don't need tons of power.  I'm fairly certain I would have been happy going forward with just those two subs and the response I had.   Response was good down to about 10hz, although human hearing seems to require ascending volumes at lower tones in order to make up for our ears' insensitivity.  But with Audyssey's Dynamic EQ, it took care of that nicely.  Everything sounded awesome with those subs, and I think I probably reached the top 10% of bassheads with those subs and response.  

 

I was using some major boost in order to get that response.  without it, there were simply nulls that could not be dealt with.  Clearly, the delay and phasing of the subs is even more critical than the EQ - it's surprising how much the delay can and will affect response, especially nulls.   I could tear the house down with these subs, no doubt.  They were loud, clear, booming and even with a lot of EQ, never once hit the red limiter at 1000W.  In most cases, it wasn't even close.  Gravity at -7db got to 3 lights flickering a few times.

 

But I was still missing something.  Hard to really say what or even share that when you already have 2 8cft monsters that look like small refrigerators :)  Even at higher volumes, I never quite felt the pressurization consistently.  Sometimes....wow, other times, just a few little blasts but nothing consistent.  The 3 seats did sound very consistent, but there were definitely some audible differences especially at the EQ'd frequencies.  

 

After having built these new subs I was eager to get them setup.  I decided after a lot of thought not to test out lots of positions with the 4 subs.  I would instead implement a form of the 4 loaded corners strategy for 4 subs, outlined in the Harman paper I shared earlier in this thread.    Well, 3 would be in corners, but one would not.  The fourth would be a virtual corner of the L-shaped room.  Why 4 corners?

 

Well first, the 8cft subs are giants.  The low end response is best in the back of the room, so I put them both back there, thinking I would get the most out of their lower end, which provided quality response down to 10hz.  The new subs with the nice wood veneer finish look great, they were placed in the front of the room.   I tested a few different positions in the front.

 

The first attempt to get the 4 working together went fast, and easy.  I EQd the response, and came up with incredibly flat curves.   It sounded pretty good.  But no major slam. For whatever reason, I was not fully satisfied.  It was way better, but the pressurization didn't seem that much more.  Hmm?  Did I EQ it wrong?   Was the EQ too much?  Was placement not working?  Was the delay not set properly?  

 

Like before, I spent a lot of time over the two weeks calibrating, recalibrating, and searching for some answers.  And thus the reason why I was happy I did not post an update sooner.  I wanted to, and planned to, but thought...I do not have the right report to offer!  It's not "that great".  What's wrong?  I figured, as always...user error :)  Something in my setups is not cutting it.  

 

I thought back to my discussions with Derrick, the other folks at the GTG and much of the reading I had done.  Why do all these sources insist on not using much EQ?  Hmmm.  Well, it would seem the actual load on the amp is severe with lots of boost.  You might be offering 1000watts through your amp, but if you boost a frequency by 8 or 10db....the actual usable wattage at other frequencies is more like a few hundred watts.   Hmmm.   Is that my issue, too much EQ?   How is it possible to get a great response without EQ?

 

Assuming 4 subs in corners should work, what else might be wrong?  And then, after a few weeks of searching, testing and retesting, I found it.  The next post will follow my process from start to finish to provide some data for Derrick's bass calibration process.

 

 

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As a rule of thumb, you don't want to bust a null.  You're just eating up amp headroom.

 

I think it's awesome the time that you're spending to get it right.  A lot of people throw a sub or two in a room where it looks good, set the gain and go.  Normally they're underwhelmed.  A little work now will pay off in a long enjoyable listening experience in the future.  Now you can work on your house curve;)

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9 minutes ago, CECAA850 said:

As a rule of thumb, you don't want to bust a null.  You're just eating up amp headroom.

 

I think it's awesome the time that you're spending to get it right.  A lot of people throw a sub or two in a room where it looks good, set the gain and go.  Normally they're underwhelmed.  A little work now will pay off in a long enjoyable listening experience in the future.  Now you can work on your house curve;)

Thank you so much CEC!  I appreciate the encouragement.

 

Rule #1 I have about all this.  I talk confidently and enjoy what I'm doing, but am always open to criticism, ideas, suggestions, or an outright - dude you're doing it wrong :)

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On 10/18/2016 at 4:11 PM, eng-399 said:

The boxes look great! Can't wait to hear what you think of them once you get them going. I had a nasty humm through out my speakers and subs. The way I fixed them and there's many way to do it... was I daisy chained a 14 gauge wire to each of my audio components in my rack. I stripped the end of the wire installed a spade fitting on the end of it and screwed it into a screw on each sub amp going all the way up to both surge protectors. As soon as I did that the humm was completely gone. Maybe try that. I had thread on Avsforum with pictures on how I did.51f24f0946ec82f744ba2f286d1669e1.jpge06d7706c565ec16548db175e42b22c2.jpg

I never had a chance to thank you either eeg.  This is really great stuff.  You may now live in a world where electrical engineering and connections/setups are simply and a no-brainer for you...but this kind of information is invaluable for us.   

 

I think...."it's called a ground loop, wtf is that?" and instead of describing it, you actually show a grounding loop in action.  Picture = million words.  So appreciated!

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27 minutes ago, RoboKlipsch said:

Thank you so much CEC!  I appreciate the encouragement.

 

Rule #1 I have about all this.  I talk confidently and enjoy what I'm doing, but am always open to criticism, ideas, suggestions, or an outright - dude you're doing it wrong :)

The theory is that nulls are sound waves canceling each other out at a certain spot at a certain frequency (the null).  All rooms have them as well as peaks.  Boosting nulls just uses amplifier power and all it accomplishes is that the waves cancel themselves out with more power.  Use the EQ to drop peaks.  I may not have explained it perfectly but you get the idea.  It's like speakers out of phase with each other, increasing the amplifier gain doesn't increase the volume.

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Rob, you are not the only one that has spent this much time.  Get it right, takes time.  It is funny with the subs in the same location you can EQ in or out pressurization, tactile response and slam.  It's all there but, where, upstairs, around the corner, lol.  The distance thing is all about phase.  Getting a good phase response will make or break a killer system like you have.  I'm going for popcorn and will be back after intermission.:D

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Update continued:

 

"The Process"

If you setup your own theater, you have a process. What that process is, is something that we all would like to define and be able to re-use in as many situations as possible.  While it would be fun to say all situations, the truth is that nothing seems to work in every situation.  But if it works in most, a process is something that provides huge value to others.  derrickdj1 shared a process at the GTG and asked for some feedback.  Here is my current process, the one most up to date and my current setup.  I reserve the right, and really the expectation, that I will redo this again, and again, and again, over time, anytime I think there is something else I want to test :)    

 

More to the point -- I expect anybody with their own ideas to make suggestions, criticisms, or share their own path, whichever they choose :emotion-21:

The only way to make me upset is to hold back what you really think and be nice for the sake of....being nice :rolleyes:

 

Subwoofer Calibration Process V1.0

 

Part One:  Setting goals and defining the Process

  • To calibrate a subwoofer or subwoofers, requires that they be integrated with the other components of the system.  The system consists of the room, the other speakers, and the other subwoofers, the amp and other system components. 
  • Placement of the subwoofers, speakers, and MLP are the most important part of the process.  In most cases, options are limited.  Making the best of them is a matter of trial and error, and experience (of having done the trial and error before).  Proper placement or best placement, could be defined as the best possible response at the listening position(s).  Defining that is critical - what are your goals?  How will you measure?  Your ears, a measurement tool or both?  
  • In my particular case, my goal is consistent response across all the seating positions.  For the purposes of this process, it is limited to the response from 10hz to 150hz.  I can, should, and will improve the rest of the response curve over time, in other threads.  I have 3 main seats in my theater that are used frequently.  I measure 5 positions across those 3 - Left, LC, Center, RC, and Right.

 

Part Two:  Individual Sub Setup for distance and level matching 

  • Once the positions of the subwoofer(s) are established, the next step is to get each setup.  The two important elements of integrating each sub is that the output (level) of each sub is matched, and then the distances from the MLP also need to be set.   I use Behringer INUKE amps, which have gain settings, and delay settings for each subwoofer individually.
  • It's a good idea to physically measure the distances to each sub.  Use a tape measure, use a laser measure, use whatever you want.  Guesstimate.
  • Plug in only one sub at this time.
  • Run Audyssey calibration using as few listening positions as possible, 1 if your version allows it.  Be sure to measure only at the MLP.
  • Write down the results of the calibration with regards to the sub:  What distance did it measure?  What subwoofer level did it provide?
  • Unplug that subwoofer, and plug in a different one.  Repeat the calibration test.  Repeat for each sub individually.
  • Using the results, change the settings in the DSP to match all 4!
  • Example:  FL sub is showing 10ft, +2.5db.   FR sub is showing 10.6ft +3db.  BL sub is showing 11ft -2db.   BR sub is showing 10ft +1db.  
  • Take the sub with the highest distance, in this case 11ft.  Adjust the delays of the other 3 subs by their differences in distance from the furthest.
  • So FL needs a 1ft delay, FR sub needs a 0.4ft delay, and BR sub needs a 1ft delay.
  • Adjust their levels to match.  With two subs, a number around 0 calibrates well, if 4 subs, a number around 2.5 calibrates well.
  • In this example, calibrate them all to +2.5db.  That means the FR sub needs to have it's gain lowered by 0.5db. The BL sub needs to have it's gain increased by 4.5db, and the BR sub needs it's gain increased by 1.5db.  That should match them all to 2.5db.
  • Re-run Audyssey for each sub using the process above to test them for distance and level.  Surprisingly, they will likely adjust very well in one try.
  • If the results don't match, tweak again and retest any that are not correct.  Once they match, you are ready to move on to the next step.  

 

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14 minutes ago, RoboKlipsch said:

Run Audyssey calibration using as few listening positions as possible, 1 if your version allows it.  Be sure to measure only at the MLP.

Rob, this is a very important point.  It does not mean you don't care about the other LP's but, they can be address later.  I do this with MCACC on the first run and do multiple LP's in subsequent runs.

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