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Discussion Starter · #23 · (Edited)
Well, I got to go to a Cars and Coffee on Saturday. Then I got to be in a car show on Sunday. Lots of folks were drawn to the car as it is very unique. The low frequencies emanating from it all day, brought its share of admirers too. It is good to have one's ego fed once in awhile. But I digress...

I accidently found I happened to already own a USB SD card reader so I loaded my most recent Favs into my DAP.
After that, I got brave and pulled my amp board out to perform a test run on my new DSR1 DSP.
Here is what the underside of my amp board looks like.

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As you can see it is quite busy under there. Below is the inventory:
(2) Carver 2 channel amps from the 80's
(1) Kenwood 4 channel amp from the last 3-4 years
(2) Beringer 1 channel noise gates
(2) Arc Audio 4 channel noise gates
(1) Valet switch
(1) Boss bass boost remote
(3) DC power terminal strips
(1) Scratch-built 12vdc to 9vdc regulator
(2) Bosch power relays
The bottom of (7) military grade capacitors
The routing of (18?) 2 channel RCA cables

With the board pulled to ease access, the pigtails for the DSP were just long enough to connect to the RCAs coming out of both of my crossovers. The power leads also were just long enough to reach one of the terminal blocks as well. I connected my DAP via front channel RCA inputs and I fired up my iPad and connected it to the DSP via bluetooth. After bravely turning it on, every connected channel worked straight away without touching the amp input gains.

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I had previously spent some time with the PerfectTune app and preloaded the time alignment settings and the basic crossover settings as well. I fiddled with various DSP levels and crossovers on the app but have not touched any of the gains on the amps yet. I played with it for about 45 minutes until my wife called me in for dinner.

Here is what I have learned so far...
I have PLENTY of SPL in my system. It is more than my ears can take already.
My Polk 4" coaxs are NOT the weak link I was worried they might be.
My 6.5"s in the kick panels (and the console) have SERIOUS buzzes, rattles, with lots of null and peak issues just as bbfoto surmised I would. By themselves they sound like crap. With every channel playing they contribute richness to the front sound stage nonetheless.
My box speakers in the back can run lower freqs than I imagined and have more than enough SPL for rear fill.
My subs need some tuning but still KICK some butt.
This is going to be fun!!!!

For my quicky hook up, I still have the noise gates between the DSP and the sub amps. I have to do some disassembly to route directly to the amp inputs. I also need to free up some real estate to mount the DSP on the bottom somewhere. I see a hell of lot of recabling in my future. I do want to learn the sources of all multiple noises and figure out the best way to correct them. I have alternator whine, ignition noise and one soft, high pitch tone when the car is not even running. It will take some time to sort out but I think I will eventually get there.

I shall soon be at the point where I will need some tuning help. That is, after I get all the hardware sorted out.
 

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That's a beautiful, clean GP! Nice work. :)

Since you have done live worship FOH mixing for so long, do you have access to a measurement microphone, RTA, or free computer-based measurement/analyzer software such as Room EQ Wizard (REW)?


UPGRADES/CHANGES:

So, if I'm correct, you want to continue using most of the gear that you've already installed, but replace your two Pioneer DEQ-7600 EQs and the two Boss Crossovers with a programmable DSP, preferably one that can be set up & adjusted via your iPad?

In addition, since it seems as if your subwoofer setup is not providing adequate output or low-end extension, are you looking to replace the subwoofers, or to keep using your existing subwoofers in a more suitable sealed or ported enclosure to improve their low-end output and power handling?

Do you have the T/S parameters or manufacturer Spec sheet for these subwoofers?


For the things that you are looking to change or update, what is your all-in BUDGET???


DSP OPTIONS & CONSIDERATIONS:

According to your system diagram, it looks as if you need a DSP with a minimum of 4 input channels and 7 output channels.

The majority of DSPs on the market offer at least 8 output channels, and a minimum of 4-6 inputs (plus at least one digital input in most cases), so I think you'll have plenty of options in that regard.

But surprisingly, very few standalone DSPs at this point in time offer complete set up and full tuning adjustments via an iPad or iOS app. :( ...or at least the ones that I would consider using in my own system. So some of the DSPs that do offer this have several downsides or unfortunate limitations IMO (AudioControl DSPs as one example).

There are some excellent multichannel combination DSP/Amplifiers by JL Audio that offer full tuning via a good iPad app, but they are very expensive, and you already have your amplifiers. You have the option to tune these with a PC or Mac as well via a direct USB connection.

Your least expensive option would be the Dayton Audio DSP-408, but just don't go there. :p There are simply too many compromises with that unit IMPO, and it only offers PC-based setup & tuning.

Your next feasible option would be the Rockford-Fosgate DSR1, which has all of the inputs you'd need, and 8 outputs as well.

The initial firmware updates & choice between the OEM integration mode vs standard aftermarket amplifier configuration mode in this unit need to be done on a Windows PC.

But from there on out can be completely "tuned" using an iOS app on your iPhone or iPad. HOWEVER, the last time I checked, their iOS app had NOT been optimized for use on an iPad. :(

Regardless, this is a small but very powerful DSP. Though it doesn't offer the pristine SQ and expanded feature set that is available from its slightly higher-priced competition (Helix DSP Mini & DSP.3 to name a few). But considering its $299 price, it does a lot, and does it reasonably well.

I won't offer other DSP suggestions until we know your Budget. But take note that buying a good second-hand unit from someone who has recently upgraded can save you a bundle.


SOURCE:

First off, how are you playing your music files???

And what file format and Bitrate are you using???

With your Pioneer head unit, are you using standard lossless CDs, or MP3s burned onto CD-R discs, or files on a USB thumbdrive, or streaming music from your smartphone or iPad over Bluetooth???


Do you use your smartphone or iPad with Apple Music or other streaming services to play your music library & playlists?

There is a fairly simple way to connect an iPhone or iPad directly to most DSPs via their digital or analog inputs.

Using a wired Apple Lightning to USB Camera Connection Kit 3 (CCK3) and a relatively inexpensive DAC such as the Topping D10, you can connect your iOS device so it acts as a digital media player and sends a digital output directly to the digital inputs of your chosen DSP via the DAC.

This setup provides a very clean, noise-free source signal to your DSP. This can also be done using Android smartphones & tablets.


SYSTEM ISSUES:

To start, it seems like your chosen setup has the following issues:

- Subpar source signal level and/or clipping.

- Poor gain structure throughout your signal chain (a terrible noise floor & SNR that necessitates the addition of noise gates!).

- Potential ground loops and/or inducted noise into your RCA interconnect cables or other wiring (alternator/ignition noise).

- Midbass/Bass cancellation nulls (destructive interference) due to midbass speaker locations.

- Improper integration & alignment of the subwoofer system + low power handling, lack of low-end extension & SPL, etc.


With so many components in your signal chain, there are LOTS of opportunities for inducted RFI & EMI noise to enter the system, and for your gain structure and S/N Ratio to be completely screwed.

I think that replacing your two Pioneer EQs & the Boss X/Os with a good DSP will be a great start! You'll gain nearly unlimited options of these functions with a good DSP, as well as the Time Alignment (digital delay).

BUT, it Always starts at the Playback SOURCE! In this case, the Pioneer DEH-6700BT.

When you start with a mediocre source unit that has poor SNR and a relatively low RCA preamp output voltage of just 2V max (best case), which also clips, you're off to a fairly bad start that can unfortunately only get worse down the signal chain. :(

The gains or input sensitivity levels of every other component in your signal chain will have to be increased to compensate, and the noise floor from your source gets amplified more & more each time through all these components in your system, as well as each of these components contributing its own noise to the signal...

GARBAGE IN = GARBAGE OUT!

So if you can afford to, you might want to upgrade your head unit to one that has at least 4V RCA preamp outputs, and one that is known to not clip the output signal even at full volume, or at least very close to full volume.

But this depends on if a traditional head unit and its RCA outputs will continue to be used as the main music playback source for your system.


SPEAKER LOCATIONS:

I'm willing to put money on your system having some serious and erratic midbass/bass cancellation nulls due to your midbass speaker locations and how they are installed in the kickpanels, combined with the drivers that are installed on either side of the center console/transmission tunnel area.

In addition, what is the Fs of these drivers and how low is your HPF set??? And is the back wave of all of these drivers completely isolated from the cabin interior & front of the speakers?

Even in a typical setup with just a single midbass in each front door, or the L&R kickpanels, there are several unavoidable cancellation nulls that appear in a few regions of the midbass spectrum.

This is simply due to the physical dimensions of the vehicle. Primarily, the width or distance between the two front doors or the L & R kickpanels where the speakers are mounted. But the intersection/boundary of the transmission tunnel or center console will also be a contributing detrimental factor.

The distances between these speakers and the other boundaries/obstructions will correspond to the wavelengths of the specific cancellation null frequencies in nearly all cases.

The placement of additional midbass speakers in multiple locations can work to provide a significant boost in midbass output, as well as smoother overall response in this frequency range.

BUT, great care must be used in terms of the timing and the phase coherency between these multiple drivers, AND the contributions of their reflective energy (comb filtering) at your listening position.

This is just one situation where a calibrated measurement mic and REW measurement software come in extremely handy!

A decent measurement microphone such as a miniDSP UMIK-1 is worth the investment IMO.

With the mic in your listening position, you can start by taking a measurement with just ONE of the midbass drivers playing, and save that response. Then measure just one midbass from the opposite side and save those results.

Then measure with two midbass drivers, and save the resulting amplitude response. Keep adding the drivers together one by one and save the results each time.

In the REW window you can select which set of response measurements you want to display and overlay them to help see the differences in response.

You'll be able to see the constructive and destructive interference in the response as you add each speaker, or the unique response with different combinations of the speakers.

Sometimes, reversing the polarity of just one of the drivers will improve the response, but will always cause an issue in another region.

And sometimes you can use a different type of X/O filter (Butterworth vs Bessel vs Linkwitz-Riley, etc.), and/or a different slope to change the phase rotation of an individual driver when it needs an adjustment that's less than a full 180°.

Some of the better DSP units have incremental phase adjustments for each output channel, as well as All-Pass filters which can help to address these issues.

But IMO, I think that your speaker locations and how they've been installed are primarily responsible for your wonky midbass & bass response.

That's all I've got time for now. Let's us know your BUDGET for these changes and upgrades???

Cheers
I had this issue but turned my 1.5v signal into a 7v signal using an rca line driver from AudioPipe. I know I am probably amplifying a bad signal, but it sounds way better than having my amp gains all the way up. Now my amp sounds great at the halfway mark. A little off topic, I know... Just thought I would share my recent experience with this using a Chinese Android Head unit signal. (It actually has a ROHM32107 dsp, and optical output which I have tested but have not experimented with. Thinking I can get a cleaner signal with a DAC to the line driver than from the Subwoofer RCA Y cable'd.
 

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Discussion Starter · #25 · (Edited)
If my source was clean but the cables were picking up noise on the way, I could see an RCA line driver helping. If my source is noisy and the cables are fine then garbage in garbage out. To try to eliminate both, I am changing my source AND cables AND eliminating 4-6 items of hardware. The noise gates work pretty well but do have some threshold cut out at low volume or at the transition of tracks. However it is MUCH less annoying than the noise floor itself between tracks.

Regarding the optical out or SPDIF/coax options, my DSR1 only has coax in. I have found that DAPs and/or HUs that have that feature are getting rarer.
 

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Discussion Starter · #26 ·
I got some free time today to try and make some improvements. I put a pink noise file on my DAP and a RTA in my iPhone 6. It turns out it was a waste of time. The RTA app fills half the screen with background noise across the whole spectrum. Playing the pink noise file looked virtually the same simply with higher levels. So I abandoned that process.

With everything still just laying loose in the trunk I just ran with it. The DSP pops my speakers when turned on. So I used some alligator clip jumpers and some tape to connect the 3 power wires for it as they should be. Problem solved.

I tried just running the just the kick panels midbasses and then tried just the console midbasses. By themselves they sound like crap. Definitely need a better drivers and some serious dampening/enclosure work. However, when all the other speakers are going the mid basses contribute very little to the overall sound. I can procrastinate that upgrade for a bit.

I played with the crossovers some more and now have my Polk 4" coaxs crossing over at 230Hz. They are now properly covering the entire range of the female vocals. The front sound stage is now about the dashboard. When I add in rear fill, I can move the sound stage into my head. Cool effect with my eyes closed. Regarding my rear-fill bookshelf speakers, I kept lowering the crossover to be now at 60Hz. They seem to take it just fine.

The subs now are crossed over at 100Hz. They sounded about the same at 80Hz. I had been running them crossed over at 120Hz for years. Now the sound clean and tight as 10's can and should. The IB installation gives them really low frequency performance without requiring lots of power (though I do have plenty available).

I did a little by ear tweaking on the EQs here and there. It probably nowhere near the optimum theoretical flat curve it should be but it sounds good to me. I may not go to the trouble to try for optimum. I noticed there are more differences in sound based on who engineered the recorded track than I will ever be able to sort with one eq curve setup. Heck just changing whether the side windows are up or down makes a big difference too. I get better faster sound clarity by just fine tuning the volume of one or two of the 8 channels. Particularly the front mid/tweets.

At this point I can live with how it sounds for this summer. I do however need to address the functionality. Having the DAP and the Master volume control laying in the trunk is inconvenient to say the least. I will probably tackle it tomorrow.

I can report that all the engine ignition and alternator whine audible at low volume is gone. Likely because all the ground loops via the RCAs from front to back have been removed from the signal path. I still have to experiment with back feeding signal to the DEQ-7600s simply for display purposes. I also have to determine if I still need the noise gates before the amplifiers. But that is a project for another day.

Has anyone come up with a good way to hold a DAP in a car? I want to try avoid wear and tear on it and its cables from just leaving it on the passenger seat.
 

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Discussion Starter · #27 · (Edited)
I worked on getting the DSP temporarily installed for the summer. I also did some signal rerouting for experimentation purposes. The miracle was all the custom length RCA cables I made years ago actually reached to the pigtails of the DSR1. I also bypassed the two 4 channel noise gates with no ill effects. I left the subwoofer ones in just for ease of cabling. I terminated and landed the ground and power connections to nearby terminal blocks without having to extend them. The system turns on and off properly without ant POPs. I still have not reworked the RCAs for the DEQ-7600s nor the HU. That will be a chore for another day. I am very happy I still no longer have any noise floor or alternator whine. That was one of my goals going in. I still have some EQ tweaking to do but I can work on that as I go along. Now I have to get my playlist sorted out.

Below are some pics of the cobbled install of the DSR1 and some settings in the app.
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That new block diagram looks MUCH better, Bill! (y)

After seeing the underside of your amp rack, I'm not surprised that you had noise and other issues! :p That was and is a bit of a rat's nest compared to the top-side. ;)

I would still try to eliminate the Guitar Pedal Noise Gates whenever you have the opportunity. ;)
Those Behringer guitar pedals use "Low-Z" (low impedance) instrument level inputs & outputs (very low signal levels). That could actually add to your noise floor because the gains on everything else downstream would need to be boosted from the very low instrument level signals to a usable line level.

Those guitar pedals have a "Send & Return" to insert outboard gear which should be at Line Level (I think), but it looks as if you are still using the Low-Z instrument input & output on them? The inexpensive 12v-9v DC-to-DC power inverters are usually a source of noise as well.


I was curious why your BOSS Bass Boost Remote was not mounted up front where you can easily access and adjust it while listening to the system? ...Oh, it looks like you said that you'll address this later.


And if you're still using the Bosch Relays, make sure you insert "Quenching Diodes" on them to prevent Back EMF. There is a guide (along with a TON of other great information) on the Basic Car Audio Electronics website www.bcae1.com under the "Relays" section (# 36). You'll find higher current Power Diodes at Automotive Supply stores where their intended use is for trailer/towing lighting systems for the trailer running/brake lights, etc. Amazon.com: Roadmaster 792 Hy-Power Diode, (Pack of 2): Automotive



Anyhow, I'm glad to hear that using the DSR1 to replace most of this gear and all of the extra RCA and power wiring has gotten rid of most of your noise issues!!!

If you still have noise issues when trying to use your existing Pioneer head unit, you could try inserting a Power Noise Filter in front of it, such as the "InstallBay IBNF 30" 12V/30-Amp Noise Filter.

Also, run the Constant 12V (+) wire for the Head Unit directly to the (+) terminal of the battery (including an in-line fuse, of course). Do the same for the Head Unit's (-) ground wire...it should go straight to the (-) terminal of the battery.

Generally, ALL power (+) and ground (-) connections for ALL system components should be from Common Point, usually from a common (+) fused distribution block and grounding point (or the negative battery terminal). That's everything from the source (head unit or otherwise), to the amplifiers, and EVERYTHING in between.

Try to avoid running RCA signal cables near fuel pumps, vehicle computer or other electric modules, or any ventilation fans/motors, because they might produce noise that will be inducted into the RCA signal cables, and sometimes into the speaker wiring.


FYI, Alternator Whine is MOST OFTEN an indication that the Rectifier in the alternator is failing, or just plain cheap. This can happen slowly over time and IME happens more often with re-manufactured alternators. I'm glad that this noise no longer seems to be a problem!

For future reference, if there is a Bosch Alternator to fit your vehicle, IME these have the lowest noise and least ripple current...IOW, very clean output, and very robust high-quality rectifiers, and overall they are high-quality and long lasting.

Some folks will automatically install a Power Filter Capacitor in the alternator/charging circuit to prevent alternator whine and provide cleaner, filtered power. Automotive Ignition companies such as MSD make Alternator Noise Filtering Capacitors (# MSD-8830), etc, but you can obviously find the generic equivalents for much less money.


For your FiiO DAP, a small in-line Ground Loop Isolator should help if you experience noise issues when using the 3.5mm headphone or line output from the DAP into the DSR1. Search Amazon for "3.5mm Stereo Audio Ground Loop Isolator" if it becomes a problem





It's also great that there are no system power Turn-On/Turn-Off pops now. FYI, most DSPs including the DSR1 have adjustable Turn-On & Turn-Off Delays that should help with eliminating those system power on/off pops.


KICKPANELS & MIDBASS DRIVERS:

We would have to see what is behind your kickpanel trim covers to offer more suggestions on potential mounting/installation improvements and better potential midbass drivers that would fit and perform well there.

I think that I addressed the kickpanel and other panel buzzes and resonances in one of my previous Mega Posts, but you can use small pieces of good quality rubberized CCF foam weather-striping, Tesa Tape, and small dabs of soft 100% silicone caulk on the back sides of trim panels and their connectors/connection points to help eliminate buzzes and rattles, along with CLD and CCF on the panels themselves to help tame resonances.

As you experienced first-hand, any buzzes, rattles, or resonances will muddy the clarity of your sound and also destroy important soundstage and imaging cues.


The DAP Mount:

The easiest solution for a lot of folks is to use a Cupholder type cellphone mount in one of the center console cupholders. Obviously this isn't a viable option in your case. But maybe you can find something similar to the aftermarket cupholder that you added to the side of the center console transmission hump. They make the smartphone mounts with a flexible goose-neck stalk or articulating arms...







Overall, it looks like you are well on your way to better sound, and it should only continue to get better with each improvement!
 

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Discussion Starter · #31 ·
That new block diagram looks MUCH better, Bill! Thank you. It is simpler now, but I will complicate it again later.

After seeing the underside of your amp rack, I'm not surprised that you had noise and other issues! :p That was and is a bit of a rat's nest compared to the top-side. ;) Oh but I tried so hard to at least make it a neat rats nest. It was the best I could do based on the real estate and cable lengths I was working with at the time. All of it is still there, it just has some of the items disabled (still powered though).

I would still try to eliminate the Guitar Pedal Noise Gates whenever you have the opportunity. ;) That is on the agenda. Based on the S/N on all the other channels I am pretty sure I no longer will need them. They are still in the circuit now simply because of cable type and reach issues. Once I tackle that, they will be archived.
Those Behringer guitar pedals use "Low-Z" (low impedance) instrument level inputs & outputs (very low signal levels). That could actually add to your noise floor because the gains on everything else downstream would need to be boosted from the very low instrument level signals to a usable line level. It may or may not have been an issue before but will not be moving forward.

Those guitar pedals have a "Send & Return" to insert outboard gear which should be at Line Level (I think), but it looks as if you are still using the Low-Z instrument input & output on them? I am not even sure which one I used. The inexpensive 12v-9v DC-to-DC power inverters are usually a source of noise as well. I would be surprised if a LM317 voltage regulator made any noise at all. There is no oscillation circuitry in it. It is just a DC buck regulator.


I was curious why your BOSS Bass Boost Remote was not mounted up front where you can easily access and adjust it while listening to the system? ...Oh, it looks like you said that you'll address this later. Well... as it turns out, the one in the pics is actually part of the Boss crossover. I never have used it. I put it there just in case. The bass boost I have actually been using is connected to both mono block amps. The problem I had was, two amps means two controls. I wanted to maintain even gain on both sides at all times. Since I was running the subs at 95% Xmax so often, I dissected them and figured out how they were wired. I determined each wire's relationship to each other when they are connected to their respective RJ45 jacks. I learned they were kind of dual-ganged potentiometers wired in a 5 wire configuration. After determining the resistance, I purchased a heavy duty 4 gang potentiometer of similar value and wired both cables to it. It is mounted discretely on the console such that my right hand naturally rests with my fingertips on it. Previously I would slowly push the bass level up to near Xmax and be at the ready to quickly attenuate the signal in the event of over excursion. With the DAP and the DSP I barely have to touch it anymore. It almost seems like one of them is "normalizing" or compressing the signal peaks for me. My listening has been much more enjoyable now that I can have it pretty dang loud without stressing out about overdriving the subs.


And if you're still using the Bosch Relays, make sure you insert "Quenching Diodes" on them to prevent Back EMF. There is a guide (along with a TON of other great information) on the Basic Car Audio Electronics website www.bcae1.com under the "Relays" section (# 36). You'll find higher current Power Diodes at Automotive Supply stores where their intended use is for trailer/towing lighting systems for the trailer running/brake lights, etc. Amazon.com: Roadmaster 792 Hy-Power Diode, (Pack of 2): Automotive. Thanks for the tip but I have been soldering 3A diodes on my relays for years for this express purpose.

Anyhow, I'm glad to hear that using the DSR1 to replace most of this gear and all of the extra RCA and power wiring has gotten rid of most of your noise issues!!! This configuration has actually solved ALL my noise issues engine running or not except for ONE very faint 3.5KHz tone in the kick panel channels. Between tracks it is literally SILENT. I think the tiny tone is a the fact that my Carver amps are 35+ years old and might have some power supply filtering capacitors losing their value. I do have a spare Planet audio 4 channel amp that may stand in if I want to go to the trouble.

If you still have noise issues when trying to use your existing Pioneer head unit, you could try inserting a Power Noise Filter in front of it, such as the "InstallBay IBNF 30" 12V/30-Amp Noise Filter. I will have to see how it goes if or when I use the HU to send signal directly to the 4channel inputs of the DSP. I am presently using the aux inputs for the DAP.

Also, run the Constant 12V (+) wire for the Head Unit directly to the (+) terminal of the battery (including an in-line fuse, of course). Do the same for the Head Unit's (-) ground wire...it should go straight to the (-) terminal of the battery. I will keep that under advisement depending on its behavior and limited usage moving forward. I actually used a couple of steering diodes to the HU "memory" wire connected to both batteries so I could disconnect one OR the other with out losing my station presets. Kind of a moot point now that I never listen to radio stations anymore. (I hate commercials)

Generally, ALL power (+) and ground (-) connections for ALL system components should be from Common Point, usually from a common (+) fused distribution block and grounding point (or the negative battery terminal). That's everything from the source (head unit or otherwise), to the amplifiers, and EVERYTHING in between. I have learned and recently understand the purpose/benefits of doing so. I will probably be doing that for my buddy's Chevelle as he has a similar set up as mine.

Try to avoid running RCA signal cables near fuel pumps, vehicle computer (You're funny, that technology did not exist in 1972. Hell, I am still running breaker points and a quadrajet carburetor). or other electric modules, or any ventilation fans/motors, because they might produce noise that will be inducted into the RCA signal cables, and sometimes into the speaker wiring. I did that when I originally did the 1st installation. I ran all the DC power wires under the driver's door sill. I ran all the speaker wires under the passenger door sill. And I ran all the RCA signal cables under the center console. They only cross each other on the amp board and their seems to be no issues at this time.

FYI, Alternator Whine is MOST OFTEN an indication that the Rectifier in the alternator is failing, or just plain cheap. This can happen slowly over time and IME happens more often with re-manufactured alternators. I'm glad that this noise no longer seems to be a problem! For an old car I have kind of a rare GM 27Si bodied alternator. My factory one was an 80A version and was a factory upgrade simply because of the car being optioned with A/C and a rear window defogger. Cadillac's of that vintage, got a 100A version in the same size case and I got a new one of those swapped in a couple of years back just because.

For future reference, if there is a Bosch Alternator to fit your vehicle, IME these have the lowest noise and least ripple current...IOW, very clean output, and very robust high-quality rectifiers, and overall they are high-quality and long lasting. (I would be surprised if there was, since my car runs V-belts and not a serpentine belt). The bracketry is special for the 27Si alternator as well compared to the more common 10Si alternators. Overall, I do not think I will ever need to go there anyway. I have been running the WHOLE amp rack on the same 50A fuse for over 20 years.

Some folks will automatically install a Power Filter Capacitor in the alternator/charging circuit to prevent alternator whine and provide cleaner, filtered power. Automotive Ignition companies such as MSD make Alternator Noise Filtering Capacitors (# MSD-8830), etc, but you can obviously find the generic equivalents for much less money. Been there done that years ago too. I scratch built a 105A rated noise suppression circuit using three TO-3 package transistors on a custom heat sink. I hid it under the front battery and it has been so reliable I have never laid eyes on it since.

For your FiiO DAP, a small in-line Ground Loop Isolator should help if you experience noise issues when using the 3.5mm headphone or line output from the DAP into the DSR1. Search Amazon for "3.5mm Stereo Audio Ground Loop Isolator" if it becomes a problem. Thank you for the tip. I actually had to buy one of these when I was using a bluetooth adapter plugged into the aux in jack of a early 2000s Chevy work van.

It's also great that there are no system power Turn-On/Turn-Off pops now. FYI, most DSPs including the DSR1 have adjustable Turn-On & Turn-Off Delays that should help with eliminating those system power on/off pops. I did not know there was a delay function in the DSR1. Anyway it works great as is.


KICKPANELS & MIDBASS DRIVERS:

We would have to see what is behind your kickpanel trim covers to offer more suggestions on potential mounting/installation improvements and better potential midbass drivers that would fit and perform well there. Understood. We will just call it ugly and inadequate for the time being.

I think that I addressed the kickpanel and other panel buzzes and resonances in one of my previous Mega Posts, A link would be nice. but you can use small pieces of good quality rubberized CCF foam weather-striping, Tesa Tape, and small dabs of soft 100% silicone caulk on the back sides of trim panels and their connectors/connection points to help eliminate buzzes and rattles, along with CLD and CCF on the panels themselves to help tame resonances. That is the plan when the time comes.

As you experienced first-hand, any buzzes, rattles, or resonances will muddy the clarity of your sound and also destroy important soundstage and imaging cues. Funny thing about that. With the Polks HP'd at 230Hz, the rear fill HP'd at 60Hz and all the energy the subs put out, at volume, I can mute and unmute the kicks/console drivers and not hear any change in sound now. I do think they could be useful at lower volumes though. (on the rare occasion when I have passengers).

The DAP Mount:

The easiest solution for a lot of folks is to use a Cupholder type cellphone mount in one of the center console cupholders. Obviously this isn't a viable option in your case. You noticed that... But maybe you can find something similar to the aftermarket cupholder that you added to the side of the center console transmission hump. They make the smartphone mounts with a flexible goose-neck stalk or articulating arms... I spent a little bit of time on ebay seeing what is out there. I will eventually come up with something.

Overall, it looks like you are well on your way to better sound, and it should only continue to get better with each improvement! ABSOLUTELY! Thank you so much for the help!

The next little issue I am working to resolve is USB power for my mobile devices. I learned that when I plug my FiiO charging cable into the USB port on the HU the music stops and the screen displays a computer connection icon. This obviously is not going to work. The DAP battery has plenty of capacity to run as long as I need it to but I have to bring it into the house to charge it. I do not smoke so I removed the only cigarette lighter in the car and covered the hole with a billet rocker switch panel that I machined myself. However, I have found this little gem and will install it somewhere handy when it arrives.

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It only requires two wires and a round 1" hole. With two ports I can charge my DAP and my phone. It even has the added benefit of monitoring my battery voltage in the car with the engine off. It was a good deal for $5.99 and free shipping. (I will like cut the cover off).

I am having fun dialing all this stuff in. For quite some time my heavy metal 4400 pound car was my SPL's weakest link. Now with the DAP and DSP, my hearing is finally the weakest link.
 

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Discussion Starter · #32 ·
Spent some time Sunday tidying up my temporary DAP/DSP install. Got the new USB/voltmeter installed into the hobby box mounted on the factory 8-track base.
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I mounted the Rockford Fosgate PLC2 control potentiometer right next to the bass control knob on the side of the console. I need to get a second "chicken head" knob for it.

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I ran all the wires under the carpet along the driveshaft tunnel. Good thing I had some abandoned RGB LED wiring to use as pull string. My new flashy (literally) USB charging cable and headphone jack extension cables came yesterday. I got them all hooked up and now right rear fill channel is silent (Bummer). I think I disturbed a bad RCA cable from the DSP to the amp while I was wrestling in the 12vdc power feed wire for the USB jack.

After a short listen of just the subs while out of the car, I need some sound deadening pretty bad. I did a little research and now have some black 80mil Siless and some 10mm CCF sheets on order. Since I have to pull the amp rack out again to install it, I will remedy the right rear channel issue at that time.

I may get my oscilloscope out of the attic and try to set some amp gains.
 

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Discussion Starter · #33 · (Edited)
I just started to install my 80 mil Siless sound deadener today. I did the inside of the driver's side quarter panel because it was the easiest to get to. I have buddy coming over tomorrow to help me with installing the rest it so I quit for the day. I bought the stuff because my car has recently acquired a new sheet metal buzz in the trunk. Well I took the car out this evening to jam in a parking lot one last time before I pull it all apart. Now the buzz is absolutely horrible! I could actually watch the left baskets move up and down nearly 1/8"! Fortunately I found out why this is happening. You see 20+ years ago, when I installed the first set of 10s, I made a plywood sandwich. From the top, the speaker grilles have 4 screws which are added to 4 more screws around each SW for a total of 8 per sub. The subs are dropped in from above and screw through a sheet of black vinyl and 1/2" of upholstery foam then into the 3/4" thick slab of plywood. In the trunk I had to cut a lot of sheet metal in the rear package tray to make holes for the SWs. There were already holes for 6x9s and some additional large holes in the middle for an optional defogger blower. To compensate I screwed about a dozen screws up thought sheet metal from the bottom up into the plywood. Well now that my DSP can send much more signal to the amps, the subs kick harder. This has resulted in the screws ripping out of the plywood causing my horrible buzz. It is a good thing I found out tonight because all the screw heads were going to get covered up tomorrow. So now my first order of business is to get the rear deck fully secured again THEN add the sound dampening sheets. It was a kind of fortunate one step forward, two steps back situation.
 

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Discussion Starter · #34 ·
Spent all day Sunday with my buddy installing additional screws into the bottom of the package tray and added sound deadener to most surfaces in the trunk. Since I had to remove the amp board, I may as well do my planned upgrades now. Below are some pics of the progress.

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I did not take pics, but the bottom of the package tray got 100% coverage around the subs.
 

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Discussion Starter · #35 ·
Took some time today to figure out how to connect the HU and existing EQ's to the system and still let them have some purpose. I ordered an Audiopipe splitter-3003 to connect the HU to the DSP and back feed signal to the EQ/RTAs hopefully without affecting the SQ of the DAP.

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