This is my new favorite thread.
Keep the pics flowing.
Keep the pics flowing.
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.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)?
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. 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.
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.
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.
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???