DSP Audio Tuning for Audio Geeks

[ralphsmithiii]

The do make a cockpit component system, which I considered by opted out due to Odin@earmarks advice on my setup:
M770-CCS-SG-TB

 

[Mainah]

Is there enough room to add speakers in the coamings? I wonder if JL makes a component marine quality just to go in the captains area. Tweets in the tower and woofers on the floor. I suppose I can go 2 way's, but rather break it out.

In the kindness way possible you have some catching up to do. @fraserjr pioneered this and many others including myself have followed. I have posted the following pic way too often but still does not get old IMO. Not only can you fit a 6.5 there including JL but you can also fit a working beer tap beside it.

https://jetboaters.net/threads/easiest-way-to-add-amplify-music-at-the-helm.12049/page-5

Boat Beer Tap

• Mainah
• Apr 1, 2018
• 3

 

[Bryan L]

In the kindness way possible you have some catching up to do. @fraserjr pioneered this and many others including myself have followed. I have posted the following pic way too often but still does not get old IMO. Not only can you fit a 6.5 there including JL but you can also fit a working beer tap beside it.

https://jetboaters.net/threads/easiest-way-to-add-amplify-music-at-the-helm.12049/page-5

Boat Beer Tap

• Mainah
• Apr 1, 2018
• 3

Oh heck no!! I love you guys!!

 

[Mainah]

I have done more more googling and reading. As mentioned this stuff can get really deep and there are some logarithmic formulas that can be used. I am going to avoid turning this into a math lesson given the point folks already made as much of this will be dependent on how I like the sound to my ear. Some of the math becomes useless even in a perfect environment which an open boat is basically the furthest from. I have been able to find some answers to my own questions as well. 24db slope Butterworth will likely be best for a sub given its narrow response range. In order to best fill in mid bass a high pass Butterworth is best for full ranges as well. As for the low pass on the full ranges that will vary based on a few things but to keep things simple I will be starting with all Butterworth 24db slopes. I found a couple of interesting reads on incorporating highpass filters on subs down at the extreme low end in that it can be very beneficial for the sub/enclosure match up along with eq at very specific freqs ranges. All of that boils down to what I am going to use as my initial crossover/filter settings. I can run graphs on the gains but it is pointless as how it sounds will very greatly. I can start at 0 db gain across all channels in the DSP with 0 db limit on each channel with the amps below clipping (already there from my tuning this past weekend). From there I will have to play with balancing float, cruise, and tow sports levels across the channel and sound spectrum. Having slopes on both sides of the signal prior to the amps will be good for both the amps and the speakers in terms of performance. The other things to play with beyond the crossovers/filters and channel gain are more fine tuning. I am pretty excited to give this a try and will be benching the DSP to input the initial settings after I make it marine grade. I am feeing more confident that this will be easier than I thought starting with amps that are already gain tuned just below clipping with specific tones (50hz for sub, 500hz for towers, 1khz for 6.5s).

Turns out the DSP I choose won’t be easy to seal because of the rotary encoder. I do have it taped off and will be conformal coating it but likely won’t try to seal it.


My starting point for the DSP:
-0 db gain master and all channels
-Flat eq all channels
-Sub channels - HP = 35hz 24db Butterworth, LP = 120hz 24db Butterworth
-Tower channels - HP = 60hz 24db Butterworth, LP = 17khz 24db Butterworth
-6.5 full range channels - HP = 80hz 24db Butterworth, LP =17khz 24db Butterworth

 

[Mainah]

Quick update. I got the dsp conformal coated, installed and even most of the way tuned while out on the water. The bottom crossover point really did help the polk subs out noticeably. Need to adjust the dap to pull out more bass in the middle of the sub range or to boost the gain more for the subs at lower volumes.

The bad is that the dsp picks up noise very bad. The blower can be heard in the speakers when it is on and volume low. A whiny noise from the engines can be noise heard through the speakers when the volume is low and when the eninges are shut of an electronic canbus type noise can be heard until the dvsr cuts off. All this noise is coming through the power wire to the polk head unit and/or the power wire to the dsp. Not only that I could see it on the oscope. I am going to have to track down the noise source. My guess is that the dsp is not power source isolated internally. I have everything grounded properly and no ground loops so perhaps some ferrite filters are all that is needed to remedy. Perhaps isolating the power source will be needed.

Beyond the slight noise annoyance with the volume down or music paused everything else is great. Super loud and plently of bass.

I will update again once I have figured out the noise issue.

 

[Mainah]

I traced down the noise problem. First thing I figured out is that with my start battery having to be replaced it was stronger than my house battery. Enough that the house battery was drawing through the engine noise when combined. The battery voltage tested fine but load tested boarderline at 25amp continuous draw. Interstate was awesome and replaced it under warranty given my issue. With the new house battery in place it did cut the noise almost completely.

With a clean signal from the radio and the noise only in the DSP according to the oscope I tried adding a ceramic capacitor in line in on the hot to the dsp and poof all of the emi noise was gone. Poorly designed power supply on the DSP was not able to handle all the emi noise in the boats electrical system but I was able to fix it. I am happy now and just need to do a bit of fine tuning. I will update with my settings and what made the most noticeable difference for me once complete.

 

[bronze_10]

I...... I read this entire post... and I wanted to understand it but wow... this is light years above me. I was just impressed I mounted my two amps and they came on when I plugged them in.... @Mainah I dont qant to ever hear your system... I think mine sounds great! If I ever hear yours I'm gonna be pissed with mine! Lol

 

[Mainah]

So got out for a bit yesterday. I tweaked a couple of settings in the DSP and the interference noise came back. As I was trouble shooting I disconnected the ground but it did not shut off although the interference noise went away. This can’t be I am going crazy right? Nope I triple checked. Either the chassis was working like a floating ground this thing consumes so little power or the rcas were back feeding a ground through circuits somehow. I know this can cause a lot of excess heat so I reconnected the ground and back came the noise. Obviously not a discrete power supply and I could fix that but there is obviously more that is not right with circuits on this taramps dsp.

Well it worked great for a short while but I am
done with this cheap electrical nightmare. Add taramps to the list of brands that I will avoid. On the plus side it was cheap and I learned that I really liked being able to dial in the crossover slope on each side of all channels in the boat. Low and behold JL makes the twk-88. It even has a tiny three function remote knob where I can set the outer ring for the sub gain, the main knob for the tower gain, and the momentary push to switch preset programs in the dsp for anything from parametric eq, to different channel leveling and mappings all with a color changing led to tell me what I have selected. I need to find a mic to hook up one set of the inputs so I can program one of the presets to combine the mic input with the head unit input. I have played around with the tun software and this thing is going to be very cool. Basically a ws420 on steroids and fully concealed behind the helm aside from that three function knob.

I checked out other brands in the process. I think JL, Rockford Fosgate, and Audio Control were the only ones I felt I could trust after research. I don’t think any of them are marine grade. I will be taking the cover off the jl to see if conformal coated and if not I will coat myself.

Back to the reason for the update. Be wary of cheap DSPs.

 

[Mainah]

First off comparing this JL twk88 to the cheap dsp I bought before is like comparing a F16 to a crop duster and I am never going back to a crop duster. I do finally have my JL Audio TWK88 DSP all dialed in for my go to "normal" mode. I will be adding a cb mic that pulls one of the pins to ground when you key the mic which will automatically activate 'valet' mode on this JL DSP which is just really a a whole different set of settings from routing to output. I am going to set valet mode such that it reduces music output to all but the towers and cut all music to the towers with the mic coming through those. Will allow the music to keep playing and as long as the mic is not being the towers prevent feedback. Enough of that aside on being able to add a mic just like a ws420.

I did have to disassemble the twk88 in order to conformal coat it. Given the number grounded double stack board stand offs and pin headers I went with mg chemicals brush on modified acrylic for the conformal coating (two coats). Tedious with the boards in this requiring a small brush and I recommend you know what does and does not need coated if you attempt this. The physical install behind the helm was dead simple having already mapped out the routing in the software on my laptop. I put the function assignable control knob in place of where my 12 volt outlet at the helm that I don't use. Having to retune all of the amps was the biggest pain.

Now for the tuning. The twk88 requires you to assign a full range input voltage for each input channel. This is a very good thing. 2v was perfect for my polk head unit never exceeding 90% on the head unit. I optimized the crossovers given what speakers they were outputting to. 48 db butterworth crossovers are certainly aggressive but apply good hard cut at the low end allowing the the speaker to fully respond to the frequencies that are sent and you don't notice it in the open environment of the boat. I rolled off the highs with 24db bw on all but the sub. We all know how quickly the low end dissipates in this environment. With the nice hard cuts in place prior to the eqs I was then able to tune the parametric eqs (I used 6 of the 8 total eq channels and up to 7 of the 10 band parametric) to make up for the loss of the lower end with each speakers best range. The result is improved low and mid end response. Still sounds a tad bright for me even with the factory tower tweaters disconnected so I may pull the high end down in the eq section in another assignable mode. All in all I really like this thing and as you can imagine from a JL product no white noise, pink noise, or any other kind of noise coming through. The resulting sound difference was enough that my wife and son both noticed it. With the engines off full power is more than anyone in the boat can bear for more than a few seconds yet it is still clean/detailed with plenty of bass/mid bass.

Screen shots of the tune I put it from the software are below. Simulation mode appears because I took the screen shots just now at home without the twk88 connected but the saved tune pulled up. I can save a tune and install in seconds when back at the boat as well. I will be copying this tune over to the other presets and then making modifications. Once installed I can swap with a quick press of the control knob and each will be indicated by the color of the led.

 

[swatski]

I am going to set valet mode such that it reduces music output to all but the towers and cut all music to the towers with the mic coming through those. Will allow the music to keep playing and as long as the mic is not being the towers prevent feedback.

No idea what exactly did you do there but it sounds like an absolutely awesome system!
And ready for a serious karaoke tournament!

--

 

[ralphsmithiii]

First off comparing this JL twk88 to the cheap dsp I bought before is like comparing a F16 to a crop duster and I am never going back to a crop duster. I do finally have my JL Audio TWK88 DSP all dialed in for my go to "normal" mode. I will be adding a cb mic that pulls one of the pins to ground when you key the mic which will automatically activate 'valet' mode on this JL DSP which is just really a a whole different set of settings from routing to output. I am going to set valet mode such that it reduces music output to all but the towers and cut all music to the towers with the mic coming through those. Will allow the music to keep playing and as long as the mic is not being the towers prevent feedback. Enough of that aside on being able to add a mic just like a ws420.

I did have to disassemble the twk88 in order to conformal coat it. Given the number grounded double stack board stand offs and pin headers I went with mg chemicals brush on modified acrylic for the conformal coating (two coats). Tedious with the boards in this requiring a small brush and I recommend you know what does and does not need coated if you attempt this. The physical install behind the helm was dead simple having already mapped out the routing in the software on my laptop. I put the function assignable control knob in place of where my 12 volt outlet at the helm that I don't use. Having to retune all of the amps was the biggest pain.

Now for the tuning. The twk88 requires you to assign a full range input voltage for each input channel. This is a very good thing. 2v was perfect for my polk head unit never exceeding 90% on the head unit. I optimized the crossovers given what speakers they were outputting to. 48 db butterworth crossovers are certainly aggressive but apply good hard cut at the low end allowing the the speaker to fully respond to the frequencies that are sent and you don't notice it in the open environment of the boat. I rolled off the highs with 24db bw on all but the sub. We all know how quickly the low end dissipates in this environment. With the nice hard cuts in place prior to the eqs I was then able to tune the parametric eqs (I used 6 of the 8 total eq channels and up to 7 of the 10 band parametric) to make up for the loss of the lower end with each speakers best range. The result is improved low and mid end response. Still sounds a tad bright for me even with the factory tower tweaters disconnected so I may pull the high end down in the eq section in another assignable mode. All in all I really like this thing and as you can imagine from a JL product no white noise, pink noise, or any other kind of noise coming through. The resulting sound difference was enough that my wife and son both noticed it. With the engines off full power is more than anyone in the boat can bear for more than a few seconds yet it is still clean/detailed with plenty of bass/mid bass.

Screen shots of the tune I put it from the software are below. Simulation mode appears because I took the screen shots just now at home without the twk88 connected but the saved tune pulled up. I can save a tune and install in seconds when back at the boat as well. I will be copying this tune over to the other presets and then making modifications. Once installed I can swap with a quick press of the control knob and each will be indicated by the color of the led.

View attachment 94575View attachment 94576View attachment 94577View attachment 94578View attachment 94579

@Mainah This is pretty sweet and I'm glad someone did it with this unit. I have my slopes all set to 24db bw including the sub but now I'm curious what it would sound like to switch the sub (now subs) to 48db.

Curious and I may be overthinking this but how did you determine the ideal input voltage at 2v? My DSP also has the same option to set the voltage and although I believe now it sounds pretty damn good, I think I set the voltage on mine to 4v based on what my truck was set to. I do have to retune it now that I added the second 10" sub, line driver, and I'm going to attempt to split my bass knob to two amps.

Edit: After looking closer at your screenshots, I can see there's a "meter" to the right of the settings. I'm guessing the RCA's produce output which increases in the meter based on voltage and you just set it to where it was in the red?

Also, it's interesting (and I'm sure purely personal taste) that you did more bumping then cutting in the eq. From what I've read in terms of eqing at least in cars/closed enviornments that it's pretty normal to cut cut cut but not usual to bump although I think at the end of the day it comes down to what sounds good in your specific environment.

 

[Mainah]

The input sensitivity will be determined by the output of your source unit. In my case I had already tested the polk pa4a in the past. 2.32 volts pre clip on BT and 2.88v pre clip on usb. This was going to be a toss up between 2 and 2.8 being I have decided bt works best for my use case (usb will be better sound so bt is a HID trade off for me). I did watch the meter when tuning and at full pre clip from source you want to see may touching into the red but not full which is what I observed at 2v with all eqs off.

My cross over slope is based upon test tones with no slop and where the speakers responded will full oomph. My subs would respond down to 29hz but very little. At 35hz they came alive and at 40hz they wanted to shake stuff loose. I could have gone with a high cut and a gentle slope but that still that would have limited the potential while sending some stuff not good at responding to. Same for the towers and cabins with the points I settled on.

As for adding instead of cutting. Max output of the twk88 is 4v and at 0db pre eq gain that give some room to add with a 2v input reference.

There is no way I would tune the same in a closed environment like a car. Wether it was the jl towers or the polk cabin speakers they all sounded better with the low to mid at about a 3db boost which I attribute to the environment as I usually leave things flat. The nice thing with a digital parametric eq is that it does not leave peaks and valleys. I did not play with the q factor but instead pulled in more points closer to smooth things out.

I will post up my other presets including the mic/valet mode when I have those done. I may or may not even switch to a bt 5.0 receiver that outputs to optical as the source given I find the bt in the pa4a wonky but love the Connext rotary encoder as the master volume HID.

The only thing lacking for me now is is when standing and driving. My ears are just too far out of the soundstage. The tower tweets help but are just too bright. There is plenty of low end bass from the subs when standing so it is really the mid that needs filled in when standing at the helm. I am considering finding some full range drivers and building some custom down firing pods to fit over where those tweeters are.

 

[Josserman]

Just ordered the new Fusion 770 with DSP tuning from the h.u. being one of my primary reason. Unfortunately after buying it I realized all the amp and speaker built in profiles are only Fusion specific. I’m hoping there is some custom options, and if so I will probably use some of your learnings. At the least I would imagine it has active cross over controls, albeit its not like I’m running separate active/active components either. I saw your comment about staging, but I think staging maybe a bit more important then you give it credit on the boat. I will say I’ve been amazed at what some of the well built DSP’s that use mics can do, especially with cheap audio gear. I had Audyssey in an awesome Pioneer elite h.u. years ago (where I ran an active/active setup), and have Audyssey at home in receiver, the difference is remarkable.

Regarding BT, are you familiar with the different codecs? iPhones limited, but have a feeling you’re probably not an iPhone guy based off this and a few other posts of yours I’ve read. Anyhow, there are some newer BT codecs that has some serious high resolution. I’ve changed my tune big time on being 100% against BT.

 

[Milwmarc]

Associate degree in audio electrical, master installer in stadiums while in college doing ice rinks, Ampitheaters, church's, 2 yachts, and many lake front venues. Car's i'm a geek on...you can CONTROL the sound environment much better than on a boat. On a boat you have acoustical issues....so what you use a Real Time Analyzer on the boat in your garage, in one bay, or an open ocean, or at 60 degree water temp or 80 degree water temp or wind direction..NOW ad in engine noise and different speeds and you have an acoustical nightmare. So with that being said...with a few degrees, several years of very technical installs, 14 vehicles, 12 boats...I can tell you. Don't go too overboard..you'll get frustrated with results in one scenario vs another..unless you are in the same area ll the time in the same conditions. When you get this done though I'd drool to hear it.

Latest rendition at 47 dad of 3 that now changing professions 12 years ago to financial advisor I set a budget of $1000 and stuck to it...yes yes yes I know that's LOW for a boat...but It accomplishes 90% of what I'll need when I have 6 others on the boat that aren't audiophile and make me play for the umpteenth time that stupid stupid rap/cowboy song with Billy Ray Cyrus. My speakers will cry and bleed playing that shit. I just gave a MINI what I did in my boat on my other thread just finished tonight.

Set a budget and stick with it. Now my car, that's a different story 2016 F150 FX4 Sport 3.5 Twin Turbo with 550 HP.
RTA's processor, DSP processor, 4 amps, 4 JL Audio Subs in enclosed engineered and port tuned boxes for the environment, 12 speakers, 3000 Watt's, Dynamat in every area you can think of...and it all looks OEM from the drivers seat, minus 2 pots for quick sub control and my IPAD hidden in the top of my armrest. But I drive that to work each and every day and up north for long stretches year round. The sound environment is controlled and the same all the time. Spend money where its makes the most difference.

But if you do go all out on the boat..I'd love to see pictures and hear it....that is if its within 3 hours of Milwaukee WI area. Good luck!

Many TOP sound engineers in the country that worked for the BEST sounding sound environments for Peter Gabriel, Prince, Pink Floyd and U2..the best of the best land those jobs...were my mentors...they all said open environment near WATER is the worst to tune for as the environment changes! I remember that lesson well.

 

[Mainah]

@Milwmarc great to have you on board. Hope you car comes with a warning for passengers. @Josserman good luck with your install. Please do post up results.

I have found that modern country music is a bit bright with the settings I most recently posted. I am going to pull down the high mids and highs just a little for when playing country. With 7 selectable tunes at the push of a button at the helm will be easy to swap. I had to build a micro amp for the electret cb mic given the millivolt output of it. Have yet to install it but should work pretty good based on my bench test. Not going to be stage quality but will get the job done.

As mentioned the polk headunit is the choke point on the bluetooth. Simultaneous high bandwidth songs suffer just a bit to the ear. Not a deal breaker but the bass and low mids are less responsive with high stuff missing some finer details on bt vs usb on these songs given the bt compression. Being picky here and many folks would not even notice.

 

[Josserman]

@Mainah Thanks, will do!

Curious did you consider buying a 3rd party BT controller that leverages a better codec? Haven’t checked but I would bet partsexpress has something pretty cheap.

I think I read in one of your posts that you kept the stock tower tweeters. My port side one was blown, and in frustration I tried unplugging thinking maybe it would sound more balanced without just the one, but realized the high’s really do need to be up on the tower to get the more direct travel to most listening positions. That said, I wonder why more people don’t spend time on this area of improvement? Sounds like from your setup your tweeters are going straight to your hu and such not being tuned through your controller?

I caved in yesterday and just added a replacement set of tweeters to my order, got the JL ones since the other speakers are JL. Have an extra 2 channels left on 2nd amp and just to have a cleaner install (one less adapter) I may run them straight to the amp vs to the hu despite the 770 having ample power.

 

[Mainah]

I am playing with the idea of adding a bt 5.1 receiver with optical out direct to the dsp. Yes my tweeters bow and swim deck are all going to the headunit at the moment. The tweeters have stock inline crossovers amd I added bass blockers for the bow and swim deck. This works out well as we like it quieter at the bow and swim deck for conversation. Not to say I won’t add a 4th amp at some point.

The issue for me when standing and driving with the tweeters on is that the tweeters overwhelm the rest for me. Really need some mids in there. I am certainly going to do something this winter. Likely going to make some custom pods out of fiberglass or aluminum to fit between the two top bars and hold some down firing full ranges. I am also surprised no one has done this yet although many have the wetsounds bar and they face that down. Downfiring 6.5s right over the drivers and co captains head with medium power going to them should fill things in nicely.

 

[Julian]

OK....am I the only one who read "Butterworth" in the first post, got distracted and

ate pancakes!!!!

Fascinating stuff @Mainah but I'm more along the lines of @bronze_10 here....I'm happy my system works and sounds ok. I still have a hiss I'd love to track down, but I just turn up the volume and I can't hear it anymore!!! LOL (yes...I'm sure audiophiles the world over are cringing at that!)

 

[orexismd]

I took mine to the audio store to get tuned. expecting DSP tuning... guy tuned it by ear- said it was not worth dsp tuning a boat due to all the changing variables. Sounds good enough, I'm no audiophile but will post system and settings soon

 

[Josserman]

I am playing with the idea of adding a bt 5.1 receiver with optical out direct to the dsp. Yes my tweeters bow and swim deck are all going to the headunit at the moment. The tweeters have stock inline crossovers amd I added bass blockers for the bow and swim deck. This works out well as we like it quieter at the bow and swim deck for conversation. Not to say I won’t add a 4th amp at some point.

The issue for me when standing and driving with the tweeters on is that the tweeters overwhelm the rest for me. Really need some mids in there. I am certainly going to do something this winter. Likely going to make some custom pods out of fiberglass or aluminum to fit between the two top bars and hold some down firing full ranges. I am also surprised no one has done this yet although many have the wetsounds bar and they face that down. Downfiring 6.5s right over the drivers and co captains head with medium power going to them should fill things in nicely.

Thank you for reminding me, haven’t been out driving the boat yet this season, and totally forgot about the overpowering of those tweeters when underway. I actually had thought about doing tower speakers just for this reason, but the acoustic design of towers makes it pointless. Love your idea of doing some downfiring 6.5’s, subscribed . I may setup the tweeters as a separate zone on my new hu. Wouldn’t it be neat if the unit could get speed data from even the chartplotter and have custom tunes for underway vs stationary, doesn’t seem all that crazy. For now I think if those tweeters are set as a different zone at least having quick volume control dedicated to them will suffice.