DIY build - need help/advice

[CECAA850]

22 minutes ago, MercedesBerater said:

How do i test the actual tuning the box turned out to be?

Easiest way is to play sine waves around the frequency that you think the box may be tuned to.  They don't have to be loud but you do need to make the drivers move.  Be careful with sine waves as they'll heat up the voice coils if you play them loud and long enough.  Play the sine waves at 1Hz intervals and watch the drivers.  When you play a sine wave where the driver barely moves or don't move at all then that's what your box tune is.

[CECAA850]

26 minutes ago, MercedesBerater said:

i'll be able to cut away any peaks with MiniDsp  and get a nice house curve i'm sure. 

Always cut peaks.  Don't boost valleys.  They're normally nulls (room cancellations) and trying to boost them doesn't help and also eats up amp headroom.

[MercedesBerater]

@CECAA850  yes, this was partly the reason i wanted to build so overkill - was if i can have a bunch of peaks, i can trim them all down and have a house curve which will hopefully help with the boomy bass  + the acoustic treatments. 

 

one step closer to  audio nirvana!   

 

MiniDsp arrives tomorrow -- just enough time for me to tinker and tweak and get the amplifier fit inside the cabinet. 

[MercedesBerater]

Got the amplifier properly installed last night and subwoofers all into position.

 

Set up Umik-1 and  MiniDSP  and started tinkering. 

 

Worked on getting time-alignment between the new dual 18' ported subwoofer and the two baby R-115SW's.  

 

SUB SETTINGS

R-115SW's             GAIN knobs at  ~1/2  (12:00 position on the knob)

Dual 18 Ported     GAIN Knob at  3rd click  (on a clock it would be starting 0 gain at 7 o'clock,  i'm at like 8:30)

 

AVR SETTINGS

master volume was set at 46  (which depending on the movie is a little less than i normally listen..i'm usually 46-48  maybe 50/52 if i'm feeling frisky)

 

 

Ran dozens of test sweeps setting  ms delay between the 3 subs and inverted the one in the rear -- achieving slight improvements each step.

 

 

ABOVE  35hz  i could probably induce gastrointestinal distress and cause an involuntary bowel movement.

BELOW 35hz  the whole system falls off a cliff.  I'm  20+db down  -- it's like there's a high-pass filter on....but there is not.  (i checked and checked.... and checked again)

 

above 35hz i was averaging  70dB  with some peaks around 76dB.   ---but it felt like i could tear walls down.

below 35hz i was around 15dB down at 30hz,   20dB down at 25hz, and  30 down at 20hz, and so forth. 

 

I tried doing an EQ and loaded that into MiniDSP in the PEQ advanced tab.   and re-ran the sweep - i was able to smooth the response (basically had to cut everything above 35hz to match the weak <35hz region), and the graph in REW proved it was working. I now have a nice(r) graph....but now everything matches that weak <35hz region.  I still have the AVR set to 46 volume and the subs are now EQ'd and outputting  60dB pretty flat 20hz-120hz.

 

Should i bump the volume on AVR and redo it all?  

Should i bump the GAIN on the big 18's  and redo it all?

When i watch videos on YouTube people are clearing 100dB with much smaller subs,   why am i only getting 60dB with dual 18's ported and 4,000Watts  which is supplemented with a pair of 15' ported.  

 

 

I know this much be user error, but i don't know what i don't know -- help!  

[CECAA850]

If there are dip switches on the back of the amp check them.  It's common for users of pro amps to overlook them.  It sounds like you have a filter engaged.

 

EDIT, it looks like you have a plate amp.  What is everything set at?

[CECAA850]

Are you CERTAIN that you don't have a driver wired out of phase?

[CECAA850]

Are you using the DSP?

[MercedesBerater]

sp1-4000 

-- i left every knob alone from factory except the gain,  i turned it to ZERO and then slowly turned it up.  

ON-AUTO-12V    =   Auto

GAIN  ---  3RD White dot

LF ADJUST -- Fully to the right  (CUT-BOOST)

CROSSOVER  -- Fully to the right  (60-120-OUT)

DELAY -- Fully to the right  (0-20MS)

 

SUBWOOFER RCA  -  LFE INPUT

 

 

i don't have any filters engaged that i'm aware of.  this plate amp from speakerpower doesn't have any places to toggle any sort of DSP (that i know of, just knobs) 

 

only filters are in the  MiniDSP  that i created.  i checked low-pass  and high-pass filtes.  checked PEQ that i created to flatten the HUGE output compared to the <35hz region. 

 

[MercedesBerater]

@CECAA850   i also had a thought.... i have the Umic-1  set up,  but i have this weird feeling that my output / input in 'preferences' was being weird.

 

i had to keep going into correct it - a few times during my sweeps it would boot the AVR off as the output field and it would do frequency sweeps from the laptop computers 🤣.  talk about underwhelming.  🤣

and a few times it kept saying the 'input' field was something called a 'realtek'.   I still was getting my REW chartings.... is it possible this thing is using a different microphone and just flat out cant 'see'  below 35hz ?   maybe it's overriding my Umic selection and using the laptop microphone??  --- but, if that's true,  why does the <35hz not feel as powerful as >35hz.   the graph i see does seem to line up with what i feel & hear. 

 

i'm going to re-check this tonight since it kind of makes sense. 

[CECAA850]

I would take all the electronics out of the equation other than the amp and sub.  Use a phone  with an 1/8" to RCA adapter and play some sweeps.  You can find them on youtube.  Once you're sure the sub and amp are working correctly start going back to your regular input chain.

[MercedesBerater]

I was aligning and doing all that work with the wrong microphone selected.

 

d’oh 

 

switched & deleted all PEQ and EQ and such.....  ended with this.   

[CECAA850]

10 hours ago, MercedesBerater said:

I was aligning and doing all that work with the wrong microphone selected.

 

d’oh 

 

switched & deleted all PEQ and EQ and such.....  ended with this.   

Nice house curve.  That should shake the foundation. 

[MercedesBerater]

@CECAA850   During testing and setting up the curve.... I later went back upstairs and my wife said the birds outside were flying frantically and they would land on a tree branch and looked like they were distressed.   — mission accomplished?  Lol 

[OO1]

4 hours ago, MercedesBerater said:

@CECAA850   During testing and setting up the curve.... I later went back upstairs and my wife said the birds outside were flying frantically and they would land on a tree branch and looked like they were distressed.   —

poor birds

[CECAA850]

9 hours ago, MercedesBerater said:

@CECAA850   During testing and setting up the curve.... I later went back upstairs and my wife said the birds outside were flying frantically and they would land on a tree branch and looked like they were distressed.   — mission accomplished?  Lol 

Next is time to piss off the neighbors.