New Stereo for my 2001 Sunsetter LXI

[Slurpee]

I love the TWK88. But it’s a slippery slope if you like to play with sound. There really is no finish line. 
 

 

[gary_tenison]

Nope...checked phases. I'll have it together this weekend and post some pictures.

[gary_tenison]

Ok. this weekend I added the Twk-88 signal processor. i had to move my amp over to make room. Its a snug fit but I got it in. It seems to have added a small hiss or hum to the system, which I can hear if the amp and processor are powered but nothing is being played. I cant notice it when playing something. Suspect I have an analog RCA signal line too close to the speaker wire maybe. Ill try to chase it down. 

I added a picture of the Twk to the photoalbum from earlier in this project string  

Also, I used a microphone and pink noise to get a first frequency plot of the system and it shows a big spike around 400hz so it may explain what I was hearing in terms of low mid range muddiness  

Lots more work here than I had expected but it is a fun project for the winter  

Ill post more as I proceed  

 

 

 

[gary_tenison]

ok...I eliminated the noise I had induced.  In any case, wanted to post an update. Key issue here is setting amplifier gains correctly...I had the amp gains set at the nominal midpoint and I just wasn't feeling happy about the sound...something was wrong. So I added the signal processor, the JLAudio Twk88....wow. This thing is amazing and is an incredible tool...cant say enough good about it as slurpee also noted above.

But, my real breakthrough came when using the Steave Meade Designs SMD DD-1 distortion detector. Got on amazon for 150 bucks...I had done some reading and this seemed like a good tool for the purposes of properly setting amp gains. Sure enough, when I used it, it demonstrated that my headunit was good and distortion free to 33 of max setting of 35. So I was happy about that...then I proceeded to set amp gains...and that's where I learned that my amp was clipping bad. I introduced 1000 HZ signal and started ramping up amp gain until the distortion light lit up and I was about halfway from min to nominal...at nominal it was clipping bad and you could hear the change. Then I moved to sub channel. Introduced 40HZ and started ramping up sub gain and it went past nominal and about halfway between nominal and max. Yay. 

There was an immediate and SIGNIFICANT improvement in sound....and the bass was powerful and punchy. 

So I worked the twk88 with pink noise (the distortion detector comes with a nice CD that has the different frequency tones and the pink noise spectrum tone) and worked to smooth out my frequency responses. The sound got better and better. I think I can still improve but it is sounding amazing. If you want to know how to do that, I used a Blue condenser microphone (109$ on amazon), and connected to my iphone. I downloaded Audiocontrol Mobile tools app on my iphone from the app store and that gives me my frequency plots on my iphone as I realtime adjust the crossovers and equailizer settings.  This process works and I am getting the hang of it now.

One problem...my front speakers are vibrating against the top of the dash...very buzzy...took me awhile but I finally figured it out. Bad news is I gotta remove the windshield AGAIN to put foam under the speaker rims so when I screw the speakers down so I wont get any buzz against the dash surface...next weekend.

At this point I have to say it sounds amazing...i think I have about 2000 bucks in it (checked my amazon spend so its about this...I also build a sub box and bought carpet for that...but somewhere about 2k all in. oh...forgot the two optima batteries and the billet aluminum mounting plates...i think another 700 there...so call it $2700 total. And a few hundred hours of labor. But it sounds amazing and I love it. 

I posted additional  pics in the album link which is posted earlier in this string.

 

Edited December 19, 2019 by gary_tenison
corrected price of equipment

[Nitrousbird]

13 minutes ago, gary_tenison said:

But, my real breakthrough came when using the Steave Meade Designs SMD DD-1 distortion detector. Got on amazon for 150 bucks...I had done some reading and this seemed like a good tool for the purposes of properly setting amp gains. Sure enough, when I used it, it demonstrated that my headunit was good and distortion free to 33 of max setting of 35. So I was happy about that...then I proceeded to set amp gains...and that's where I learned that my amp was clipping bad. I introduced 1000 HZ signal and started ramping up amp gain until the distortion light lit up and I was about halfway from min to nominal...at nominal it was clipping bad and you could hear the change. Then I moved to sub channel. Introduced 40HZ and started ramping up sub gain and it went past nominal and about halfway between nominal and max.

 

I have the DD-1 and also the CC-1.  You would be amazed at how far off the crossover markings are on some amps.

Also, if you use your phone as your main source, rip the CD to a lossless format and play the phone when testing as well.  

[granddaddy55]

That device works so well setting the HU max and each amps gain, takes out the guess work.  My buddy had one and he was eager to get more than one use (his stereo) out of it,  one thing I noticed is my system is so much better on a Wetsounds source ( blue tooth rocker switch to WS EQ to WS amp to WS speaker) than with the HU as source at max undistorted volume.  I only use my HU now for an alternate main source into the EQ.  I think yours isn’t a WS system but it did make a real difference for me,  My HU source had more distortion at the speakers on the same track 

Edited December 18, 2019 by granddaddy55

[gary_tenison]

Yes I agree that at high powered systems any unclean source signal creates noticeable noise. 

My system is Alpine everywhere except for the signal processor. I wasnt convinced they had a better option than the twk88. 

Edited December 18, 2019 by gary_tenison

[Slurpee]

@gary_tenison, awesome job!  I bet it was eye opening about the distortion and where it occurred.  I can't use my Fusion Head-Unit on any source above about 90%.  Not because it clips, but it does start distorting.

I love the TWK-88.  And I like that distortion analyzer.  I've been hooking up an Oscilloscope to look for clipping and distortion.  And it works great, but that's not something most people have.  It just happens to be something I use for work.  So great tip!  And I'm going to look into that frequency response app and microphone.  I use REW and a UMIK-1, but it requires a laptop be in the mix.  Sometimes I don't want to drag all that out just to tweak something.

Did you use the TWK88 to set time delays to get sound aligned for the driver's seat?  Or the center of the cabin or whatever?

[gary_tenison]

I havent done time delays yet...I was unconvinced if I wanted to set a soundstage given that people are all over my boat...although, for my own interest, maybe when I am driving the boat alone, I should set the driver soundstage. Come to think of it...I could preload different soundstages since I can easily switch between them with the twk...so I could have first configuration set for driver, second for midpoint in boat, and third for center back seat...that could work out great. 

My Christmas vacation starts friday after work...so I will be spending lots of time working on my boat and my stereo. I will do it. Let you know how it sounds.

 

[Slurpee]

Gary, that’s how I have mine set. I also have them adjusted a bit for driving down the lake. The house curve for a boat running down the water is pretty tilted, definitely not flat. Lots more bass and more mids.  And while we don’t just float and socialize I do have a setting for just loud, flat, and clear for that one time a year I tie up somewhere. That’s the nice thing about the DSP. If you’re so inclined. 

My thought was, “I’m the idiot who paid this much for a toy. Now that I fixed the sound. I want to be the one who hears the best sound.” Lol. 

[gary_tenison]

Yeah...convinced me...I am pulling the boat out of the garage and into a large parking lot to re-run baseline frequency curve and apply equalization. Afraid the garage walls have messed up my responses. I will also set a driver seat timing and a rear seat center timing. Anxious to give it a run. Ill plot baseline curves in open field for no eq adjustment, and my best eq flattening. Very anxious to spend the day on it...yesterday I spent the day pulling off the windshield and remounting front speakers with the same foam insulation strips from my window mounting (listed at top of string)...and replacing windshield again. What a huge pain in the a**...but the speakers were buzzing against the dash. That made a HUGE difference in sound...so I highly suggest everyone do this.

[gary_tenison]

Update today...I spent much of my Holiday break working on the stereo and I posted some new pictures. I am using the Audio Control "Mobile Tools" app on my iphone, connected to a Blue microphone.

One important lesson learned. In one of my pictures of my PC screen, you can see a little box to the left side which lists the input sensitivity settings for each signal processor channel. You have to get this set correctly. If you set the sensitivity too high (like 4 Volts), there with be high quality sound, with zero buzz or hiss, but it kills your useful amp power output. So there is a trade here. If set too low, like 1V, you may start to hear some amp power noise on your speakers. I tried it several different ways and hit on 2V as optimal. System produces good power with no noticeable backround hum or noise of any kind. 

I was trying to use the fast fourier transform mode but after reading more extensively, it seems I should have been using the real time analyzer or "RTA" function. I posted a picture of RTA plots for the stereo. The red bars show the sound power levels at each frequency (as I play pink noise) while the little green horizontal bars show the "uncorrected" readings with FLAT equalizer settings. The red bar chart that is titled LF Base is for the left front speaker. The red bars show the "corrected" or equalized sound readings and the green horizontal lines show the original uncorrected readings...so you can see it is being flattened out. Each little vertical square box is 3dB, which is noticeable difference. So a little box on the chart is important. I am not done yet...I am adjusting my bass power higher as you can see on the red chart it was set too low. I dialed up the bass power (gain) on the amp.

Best process seems to be to do each speaker separately in an attempt to smooth each speaker output, one speaker at a time. So I use the signal processor to click off all speakers and then just click on the one speaker I want to work with. I play pink noise at about 85dB and then while watch the RTA plot real time on my iphone, I adjust the equalizer settings for that speaker until I get as flat a plot as possible. Then I also record the Baseline plot for that speaker, which is Pink noise with NO equalizer adjustments. I can then overlay them like. I did on the red bar chart I uploaded.

Once all four speakers were adjusted nicely...and I took a quick pass through the bass speaker, i then played all speakers with pink noise. Interestingly, even though I had all four speakers adjusted well and producing a nice even "flat" pink noise chart, once I played them all together at the same time I found a few spikes...one was around 2500Hz...as you can see on the Eq2 channel, I pulled the EQ down 9db on 2500hz...crazy. But it does sound great now.

I also installed the remote control knob on the left side of my dash. I drilled small holes for the light and the knob and ran a line over the the signal processor and plugged it in. This knob controls volume and bass separately. You can either use the headunit or the knob, but the knob is awesome. I just set my head unit at high power and then do it all from the knob. But the knob is super powerful, because I can set the soundstage at different places in the boat (I made 3 separate configs 1 for driver position, 2 for ski pole center, 3 for rear seat center) and then I can simply press the knob in and it changes the soundstage. the LED light changes to the color I preset for each soundstage. I set blue for driver, green for ski pole, and yellow for rear seat center. The primary difference for each sound stage is the speaker distances from the position. You input the speaker distances in the configuration, and it calculates the required delays at each speaker in order for all sound to reach your ears at the same time. It makes a HUGE difference in sound.

I LOVE how my stereo sounds.  I will post final plots soon, but you can see my config for rear center seat through the pictures I posted.

See pics on link...   https://photos.app.goo.gl/sjRoh5mZNX5wiEoS6

 

Thanks

 

 

Edited January 2, 2020 by gary_tenison

[gary_tenison]

Little update here as I continue to learn. I incorrectly mixed to different types of crossover curves by using a B-W curve on bass and an L-R curve on my mids. Apparently, you need to keep the same type of curve to get the correct "summing" of the two curves across the cross-over gap. So I changed that. I use two L-R curves now (4th order 24dB curves.).

Now, maybe someone can answer a question for me. When I set me bass channel gain using the SMD DD1 tool, it set a very high gain if done directly through the amp...however, if I set the gain at the amp, after the signal has gone through the signal processor, the gain sets much lower before distortion sets in. And this has caused my bass to be less powerful. SO I considered using the signal processor just for front and rear channels, but run my base RCAs directly into the amp for the base channel only (bypassing the processor just for the bass channel)...however, then the base becomes unlinked to the front and rear speaker volumes when attempting to use the remote knob I installed. So, I guess I can do it if I disconnect the remote knob. But I like that knob because the soundstage function really makes a difference in sound.

So my basic question is  - 

Is it correct to set amplifier gains using the signal which goes through the signal processor, or is it correct to set gains using a signal direct to the amp, even though in use the signal will be going trough the processor first?  I am a bit surprised that the processor seems to have introduced distortion at lower gains. 

Maybe with enough reading and you tube vids I can figure this out...

[gary_tenison]

SETTING Amplifier and TWK88 and HU GAINS CORRECTLY.

Update. I can now explain how to do this correctly. Once everything is wired up. Make sure the headunit is flat...the base, treble, or eq is all flat or off. Make sure your signal processor settings are all flat. No crossover settings, no EQ settings...completely flat. You can do this by creating a profile (I named the profile "Set Gain"). In the profile make sure all EQ is off...all crossovers off, and the red speaker button is pressed (make sure your speakers are OFF),  so all speakers are off. Make sure all amplifier settings are off or minimal...for instance, all gains are set to 0, all band passes are wide open,  such as your sub channel make sure its set for all pass or as high a setting as your amplifier allows. On my Alpine I think its 400HZ, so I set to 400 HZ. On the mid channels you would turn the high pass down as low as it goes, or 0/off if possible.

Connect your twk88 to your PC with the LONG USB cable. Download the  "setgain" profile to your twk88. Then, go to your signal processor unit (input side RCA's....coming from headunit), pull the rca lead off the left front channel of the signal processor input, plug the RCA from the headunit directly into the top of the SMD DD1 and turn it on.  Play the 1000 HZ - 0dB signal on the headunit. Turn the headunit up to full volume,  On my Alpine HU, 35 is max, so I set to 35. Now look at the DD1...the 1000hz light should be lit, showing you have the signal, if your distortion light is on, start decreasing HU volume until the light goes off. Note what number you can use (if light went off at 32 then 32 is highest UNDISTORTED setting you could use. Now check right front, left rear and right rear...the lowest of the undistorted volume settings is then your highest volume you should use your headunit for (you might even want to go one click lower on HU to make sure there is no HU signal distortion. So you will set your headunit at that volume for the rest of these tests (although if you have a subwoofer signal RCA, you do the next step below...THEN your done with HU)

If you have HU base channel RCA, then also check your base channel. Use the 40hz - 0dB track. Unplug the sub channel RCA if you have one, and check HU volume setting again. Note the highest volume setting you can use before distortion light comes in, Ok...that tells you about your HU volume setting... 

Now, on your TWK88 setup tab (on your laptop), on the upper left hand corner of your screen, you see the "input"  button...press that and it opens your "input sensitivity" table, which is your GAINS for your signal processor. It took me a while to figure this out. Now you pull the RCA OUTPUT coming out of the signal processors and into the amp (pull it at the amp).  So first Pull the left front speaker RCA which was going into your amp from your DSP and plug it into your DD1 instead of the amp. Now, with your CD playing 1000HZ -0 dB signal, start at highest voltage on channel one (7.1V) is the highest I think), and keep decreasing the voltage until the distortion light COMES ON. When the light comes on, go back to one level higher voltaage and thats your properly set gain for that speaker. Now plug the DSP output RCA for the right front channel into the DD1...go to input tab and start decreasing voltages on channel 2 until distortion light comes on etc...do for all channels. Use the 40HZ -0dB signal for the bass test and decrease voltages until the light comes on...so when I was done my front channels (1 and 2) were set at 2V. My rear channels (3 and 4) were set at 2.8V, and my base channels (5 and 6) were set at 350mV. Boom!

Now you go on to the amp...with all the RCAs hooked up, and all gains set to zero, remove the amp speaker wires. Use the cable that came with the DD1...plugged into the DD1 so you have a red lead and a black lead coming out of the top of the DD1...Play 1000HZ - (-5)dB signal from CD and put your leads on the left front speaker connectors on the amp...red on red and black on black. Now start turning up the gains for channels 1 and 2 until the 1000Hz light comes on and until the distortion light comes on. When the light comes on, slightly turn down gain until the light turns off again. Do that for all channel gains except for bass. Then set bass gains the same way but using 40Hz -(-10dB) signal. 

 

Thats it!...gains are properly set. Man, it shouldnt be that hard to figure it out but I had a hell of a time finding all the right info... If you put a stereo in your boat and never did this...DO IT NOW. It will make a HUGE difference. I GAURANTEE IT>

 

 

 

 

 

Edited January 27, 2020 by gary_tenison
Made clear it that topic was setting gains correctly

[Slurpee]

Nice. That should be pinned. I have no comments. 

I should try the DD1. I use an o-scope and it’s cumbersome for fast tweaks. 

Now you should try tuning individual speakers over frequency and playing with time delays. 

Or just call it a day and go play!

[gary_tenison]

Slurpee. Thanks. In fact i did tune each individual speaker and input time delays for driver, skipole, and rear seat center positions. It does make a HUGE difference. 

If you look at my google photos you can see each of my plots. 

 

I setup the system so left front (LF) speaker channel is channel 1. Right front (RF) is channel 2, left rear (LR) is channel 3, right rear (RR) is channel 4. Channels 5 and 6 are linked and setup as mono channel for sub.

 

my album ...https://photos.app.goo.gl/sjRoh5mZNX5wiEoS6

 

Edited January 13, 2020 by gary_tenison
added detail

[gary_tenison]

Continuing to improve the sound. I updated all info on the google album showing all my settings and plots.

[gary_tenison]

Some additional learning to share for anyone who plans to do this to their boat...my configuration has changed a bit more as I play with this signal processor and begin to get a bit more sophisticated in my approach. When you are tuning each speaker, you have to tune for the listening position. At first, I was tuning each speaker at the skipole, meaning thats where I placed my microphone and read the pink noise signal coming off the cd player. Then I simply copied that "profile"  to make listening positions for the driver seat and rear center seat positions. Turns out, thats not right. Need to tune each position separately. For instance, if you make a profile for the driver position, you want to place the microphone where your head would be. Measure the distance to each speaker for your head position and input the distanc es so proper delays can be handled...but then you also need to EQ each speaker from that position (when you are doing this, run your stereo near full power...around 90dB of pink noise) as the sound map will be completely different there than at skipole or rear of the boat. Then, once you tune each speaker from that position (turn off all other speakers and only play one speaker at a time), you will need to take about 4-5dB off the right front speaker to adjust the soundstage, because that right front speaker is too close to you and overwhelms the left front speaker. Once I figured that out, it made a PERFECT center soundstage. 

Also , I have settled on a great way to tune with the TWK88...I start on the far right side (high frequencies) and pull them down to get a gentle down slope across frequencies from about 4khz on out. This sounds best to your ears...Dont try to fill in holes too aggressively. I think my max sound increase is 3db to fill a frequency gap. I almost universally "pull down" to create the EQ map. Start on the far right and build a gentle slope down...then keep moving left and assigning a frequency adjustment point for each peak that you want to pull down. Keep moving left and keep adjusting to make a smooth curve up, relatively flat across the midrange, and then sloping down.

With your pink noise playing and watching your RTA plot from your audio controls mobile app, you then reverse polarity on each speaker one at a time and you will be able to see the red bars on your sound plot go up or down as a result. If it goes down, thats the wrong polarity. Switch it back. If it goes up (frequency bars go upwards) then thats the correct polarity. It's a breeze with the TWK88.

You can also play with your crossover points...and watch the impact in the same way. I settled on 85hz as my crossover from bass the my 6-1/2" alpines. I had started it higher and I learned the error of my ways...

This weekend Ill post new plots on my linked google photos. Anyone please feel free to ask questions if you are using the twk88...My stereo is sounding incredible.

 

 

 

 

Edited February 19, 2020 by gary_tenison

[gary_tenison]

I updated the google photo album with latest TWK88 profile settings...the stereo sounds awesome and distortion free.

[Slurpee]

I need to get all my plots for the MVi amps done and posted to.  The amps are really nice, just like having the TWKs built in and then some.  I actually got a good solid day last weekend finally tuning individual speakers and it's awesome.  I hope to get another day tomorrow to finish tuning them for the driver and get a general center cabin position done.  I had to pull a sub box out and do a repair that was needed when I got to that speaker.  But even without the second sub it thumped. 

Interesting note.  I got some complaints that it sounded bad in the back of the cabin and they weren't entirely wrong when you move from a perfect stage at the driver and walk back there.  It's a long way from the driver's seat to the back of the 25LSV cabin.  Definitely changes things.  So a Crowd Pleaser tune is needed for busy days.

Did you tune your tower speakers if you have them?

Are you really rolling off 20dBA from 4kHz-16kHz?

[gary_tenison]

Hey Slurp, Sounds like rear. tune needs polarity switch...

Nope, no tower here. I am just rocking my original 2001...the best thing I ever did for my family. We have had so much fun on that boat as a family.

The pictures of your boat look awesome. What lake. are you on?

 

Gary

[Slurpee]

On 8/14/2020 at 8:38 PM, gary_tenison said:

Hey Slurp, Sounds like rear. tune needs polarity switch...

Nope, no tower here. I am just rocking my original 2001...the best thing I ever did for my family. We have had so much fun on that boat as a family.

The pictures of your boat look awesome. What lake. are you on?

 

Gary

I loved my 2001 VLX.  I miss it all the time. Best crossover boat ever  

I thought about that after reading through your steps and checked. It’s all the correct polarity. It’s like walking off stage left after being front row center at a concert. Just muddy. Loud, clear, but messy. I moved the speaker distances around to change the stage location and it sounds much better for the cabin. I even played a bit with gains on the pilot speakers to still make it a decent sound for the driver. I’ve still got my tune for when it’s just me and the boy though!

Thanks. We’re down in Texas on Lake Granbury. Part of the Brazos River. 

Edited August 18, 2020 by Slurpee

[dhcomp]

Good read.  Headed down the DD1 path after all this reading.  

 

Was considering having someone professionally tune my setup once it was completed, but this seems like a better plan.

 

Did you buy the crossover one too?  Or just the DD1?

 

Thanks!

[gary_tenison]

I was using a good digital signal processor (Twk88) and didnt feel I needed independent check of the crossover. I also used the Audio controls mobile tools package on my phone and connected to a audio controls microphone (SA 4140)...plugs directly into your iphone. Just buy a microphone stand and you are in business. It was a fun process and my stereo really sounds amazing.

[sfarisminhas]

@gary_tenison

On 1/12/2020 at 5:23 AM, gary_tenison said:

SETTING Amplifier and TWK88 and HU GAINS CORRECTLY.

Update. I can now explain how to do this correctly. Once everything is wired up. Make sure the headunit is flat...the base, treble, or eq is all flat or off. Make sure your signal processor settings are all flat. No crossover settings, no EQ settings...completely flat. You can do this by creating a profile (I named the profile "Set Gain"). In the profile make sure all EQ is off...all crossovers off, and the red speaker button is pressed (make sure your speakers are OFF),  so all speakers are off. Make sure all amplifier settings are off or minimal...for instance, all gains are set to 0, all band passes are wide open,  such as your sub channel make sure its set for all pass or as high a setting as your amplifier allows. On my Alpine I think its 400HZ, so I set to 400 HZ. On the mid channels you would turn the high pass down as low as it goes, or 0/off if possible.

Connect your twk88 to your PC with the LONG USB cable. Download the  "setgain" profile to your twk88. Then, go to your signal processor unit (input side RCA's....coming from headunit), pull the rca lead off the left front channel of the signal processor input, plug the RCA from the headunit directly into the top of the SMD DD1 and turn it on.  Play the 1000 HZ - 0dB signal on the headunit. Turn the headunit up to full volume,  On my Alpine HU, 35 is max, so I set to 35. Now look at the DD1...the 1000hz light should be lit, showing you have the signal, if your distortion light is on, start decreasing HU volume until the light goes off. Note what number you can use (if light went off at 32 then 32 is highest UNDISTORTED setting you could use. Now check right front, left rear and right rear...the lowest of the undistorted volume settings is then your highest volume you should use your headunit for (you might even want to go one click lower on HU to make sure there is no HU signal distortion. So you will set your headunit at that volume for the rest of these tests (although if you have a subwoofer signal RCA, you do the next step below...THEN your done with HU)

If you have HU base channel RCA, then also check your base channel. Use the 40hz - 0dB track. Unplug the sub channel RCA if you have one, and check HU volume setting again. Note the highest volume setting you can use before distortion light comes in, Ok...that tells you about your HU volume setting... 

Now, on your TWK88 setup tab (on your laptop), on the upper left hand corner of your screen, you see the "input"  button...press that and it opens your "input sensitivity" table, which is your GAINS for your signal processor. It took me a while to figure this out. Now you pull the RCA OUTPUT coming out of the signal processors and into the amp (pull it at the amp).  So first Pull the left front speaker RCA which was going into your amp from your DSP and plug it into your DD1 instead of the amp. Now, with your CD playing 1000HZ -0 dB signal, start at highest voltage on channel one (7.1V) is the highest I think), and keep decreasing the voltage until the distortion light COMES ON. When the light comes on, go back to one level higher voltaage and thats your properly set gain for that speaker. Now plug the DSP output RCA for the right front channel into the DD1...go to input tab and start decreasing voltages on channel 2 until distortion light comes on etc...do for all channels. Use the 40HZ -0dB signal for the bass test and decrease voltages until the light comes on...so when I was done my front channels (1 and 2) were set at 2V. My rear channels (3 and 4) were set at 2.8V, and my base channels (5 and 6) were set at 350mV. Boom!

Now you go on to the amp...with all the RCAs hooked up, and all gains set to zero, remove the amp speaker wires. Use the cable that came with the DD1...plugged into the DD1 so you have a red lead and a black lead coming out of the top of the DD1...Play 1000HZ - (-5)dB signal from CD and put your leads on the left front speaker connectors on the amp...red on red and black on black. Now start turning up the gains for channels 1 and 2 until the 1000Hz light comes on and until the distortion light comes on. When the light comes on, slightly turn down gain until the light turns off again. Do that for all channel gains except for bass. Then set bass gains the same way but using 40Hz -(-10dB) signal. 

 

Thats it!...gains are properly set. Man, it shouldnt be that hard to figure it out but I had a hell of a time finding all the right info... If you put a stereo in your boat and never did this...DO IT NOW. It will make a HUGE difference. I GAURANTEE IT>

Thanks for this response, this is similar to how I have tuned my car. I only have one pair of RCA's running from my headunit to the TwK88. This is deliberate as it sends one full flat signal to the DSP. My HU clips at volume 46/50. There is something that I think you have missed out which I would like you to expand upon please? After establishing your max unclipped headunit volume, you moved onto the outputs of the DSP and at your max volume you played the test tones and kept an eye on the distortion light on the DD1. On the input side of the TWK, what bars were showing, and what bars were showing on the output side? JL Audio have stated that those bars should remain in the yellow. Green shows that there is signal, but weak, and red shows a clipped signal. I am curious to know what this is because all my inputs are set to 4v and it shows slight clipping on the DSP but no clipping on the DD1. Is this something you took a note of? Thanks