DSP + 4 Channel Amp + Front Stage!?!?

For an active 2 way setup like this you need one DSP channel and one amplifier channel per driver (2 woofers + 2 tweeters = 4). So you got the Minidsp and hopefully you purchased the miniDC for a car install. It helps alot with noise issues.

Now you'll get your signal from the LOC (hopefully this car doesn't have some crazy processing and the LOC will send a flat full range signal to your MiniDSP). The DSP has 2 inputs (connect to the LOC) and 4 outputs (connect to the amp) so connect the RCA how you would typically.

Next you connect the corresponding drivers to the amp, so if you decide that DSP channel 1 is the Left Tweeter, connect that RCA to Channel X on the amp, and make sure that amp channel is connected to the tweeter.

Before you fire up the system you need to set some crossovers to protect your drivers. You're not running any passive crossovers so your speaker not protected (tweeter being the main concern). Load up the software and set some nominal Xovers settings. I would start with 80hz HPF and 3000 Hz LPF on the mid woofers and 3000 Hz HPF on the tweeters. Linkwitz-Riley (LR) 24dB (4th order) to start with.

Next you probably need to start down a tuning guide to get things sounding good. Starting with setting TA, then Xover, than EQ, etc.

For calculating TA

tuning guide

If you haven't purchased the gear I would probably make some better recommendations for the money. Also you need to do some research regarding the the factory system and how best to install a LOC or get that flat, fullrange input signal.

You should also provide some info on the car and speakers your planning to install, as well as, other info about the install if you want better recommendations.

Diagram


I have the 2way advanced plug in for the minidsp 2x4 if you have questions about setup. Pretty easy to use once you get use to it. If you have a microphone and REW you can generate some Auto EQ stuff that makes tuning a little easier.

Ok it’s making more sense to me now. I didn’t understand people saying use 2 channel on a 4 channel amp. My car is a 2016 Chevy Cruze limited with the stock radio and no navigation or any extra stuff so I'm hoping there isn't any eq stuff happening. The forum I came from was for cruze owners and more specifically gen 1 cruzes where the interior design is similar and it was recommended to tap the front door speakers. I'm assuming I'll get a full range from there. I couldn't find any information online about the signals being sent to which location. Everyone just told me to I'd have to test the locations myself but I don't have the tools to do so atm. I did purchase the minidc and the moderator who put out the recommendation for the tweeters and woofers also had tune files available for the various pairs he chose. So I downloaded the files for my tweeter/woofer setup and loaded it onto the dsp using the advanced 2 way plugin. I’m not that advanced yet to know how to go about self tuning and I also didn't purchase a mic to do so but the moderator said his tune file would get you pretty close in the ball park. Maybe just physically measure your distance from how you sit in your seat to the drivers and adjust from there in the application.

I’ve purchased all the gear already so I’m hoping I can get everything working and sounding how I’d like. I actually made a diagram of how I was planning on wiring my stuff but after reading this I’ll have to change some things. Another concern of mine was how do I go about powering everything? Where should I get power from? Can I tap my loc, dsp, and other amp off of my main wire that lands in my sub Amps battery terminal or do I need to install a distribution block and send 1 lead to my sub amp and the other to my loc,dsp, 4ch amp? Also should I add inline fuses for my loc and my minidc? Same with the ground should I individually ground every component or can I tie them together at the amp or get another distribution block. The remote wire is a question as well. There are multiple components with remote in and out now. Before I just ran an add a circuit from my fuse box back to my sub amp. Now I've got multiple things that need remote signal. Can I run every remote in from my amps remote in? Or should I run the remote wire to my LOC remote in and then run the remote out from the loc to my two amps, and the minidc? I’ll post my diagram I made when I get off work. I’ll also add more info on my tweeters and woofers that were recommended.

Diagram added and it's a bit messy but I just tried to visualize how this will all tie together and then I can plan the install from there.

Woofers: Silver Flute W17RC38-04 ohm 6-1/2" Wool Cone
Tweeters: Vifa BC25SC06-04 1" Textile Dome Tweeter
4ch Amp: Amazon.com: Alpine KTP-445U Universal Power Pack Amplifier

Cross said:

Ok it’s making more sense to me now. I didn’t understand people saying use 2 channel on a 4 channel amp. My car is a 2016 Chevy Cruze limited with the stock radio and no navigation or any extra stuff so I'm hoping there isn't any eq stuff happening. The forum I came from was for cruze owners and more specifically gen 1 cruzes where the interior design is similar and it was recommended to tap the front door speakers. I'm assuming I'll get a full range from there. I couldn't find any information online about the signals being sent to which location. Everyone just told me to I'd have to test the locations myself but I don't have the tools to do so atm. I did purchase the minidc and the moderator who put out the recommendation for the tweeters and woofers also had tune files available for the various pairs he chose. So I downloaded the files for my tweeter/woofer setup and loaded it onto the dsp using the advanced 2 way plugin. I’m not that advanced yet to know how to go about self tuning and I also didn't purchase a mic to do so but the moderator said his tune file would get you pretty close in the ball park. Maybe just physically measure your distance from how you sit in your seat to the drivers and adjust from there in the application.

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Oh interesting, so someone already did the tuning with these drivers and amp for your car (hopefully the same amp as you will need the same output level he used). You just have to install them in the same location. It also assumes your head position woulds be in the same location. After you get things installed you can start playing with the tune a bit mics are 50-100 $ and the software is free, just requires a windows laptop.

With regards to TA, you might have to set that a bit differently if the location of the subwoofer is different than his. Because the subwoofer is the furthest away from you, the delay for the subwoofer is Zero. Which for you is important since the DSP is only 4 channels for the front stage. Next you delay the drivers that are closer to your head with respect to the subwoofer.

Here is an easier calculator for you to use.

Cross said:

I’ve purchased all the gear already so I’m hoping I can get everything working and sounding how I’d like. I actually made a diagram of how I was planning on wiring my stuff but after reading this I’ll have to change some things. Another concern of mine was how do I go about powering everything? Where should I get power from? Can I tap my loc, dsp, and other amp off of my main wire that lands in my sub Amps battery terminal or do I need to install a distribution block and send 1 lead to my sub amp and the other to my loc,dsp, 4ch amp? Also should I add inline fuses for my loc and my minidc? Same with the ground should I individually ground every component or can I tie them together at the amp or get another distribution block. The remote wire is a question as well. There are multiple components with remote in and out now. Before I just ran an add a circuit from my fuse box back to my sub amp. Now I've got multiple things that need remote signal. Can I run every remote in from my amps remote in? Or should I run the remote wire to my LOC remote in and then run the remote out from the loc to my two amps, and the minidc? I’ll post my diagram I made when I get off work. I’ll also add more info on my tweeters and woofers that were recommended.

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You need to make sure the power wire you ran for the subwoofer has enough capacity for the addition amp. I would recommend a fused distribution block. Even this cheap one works well enough.

This is a combo power and ground block.

For the smaller loads like the miniDC, LOC, etc use the in line fuse (5amp or whatever) on top of where ever you install in the distribution block if it doesn't include a fuse with the correct current. For example, say your miniDC has a 5 amp fuse and you run some 12 gauge or 14 gauge wire. The smallest fuse size is 30 amps (from the distro block above) so to properly protect the wire from shorts you need an inline fuse of the appropriate size.

Another option would be to use a distroblock like this for the smaller devices. This option works pretty well since your 4 channel amp has current rating of 15 amps and the LOC and miniDC/DSP is probably around 5 amps. The subwoofer power could just pass through the terminal.



I think this option 2 is technically the correct way to do it but you could probably get away with option one without burning anything down.




Ok for the remote wire I would take your switched power from the vehicle and run that directly to the miniDC. If the LOC is "on the way" to where ever the miniDC is installed than its Ok to wire it inline with that first. However, you will want every amplifier wired off the miniDC remote out because it has a delay on/off. If the you have some amps turning on and off at different times you can sometimes get a thump. It also makes things easier to wire when you simply daisy chain from miniDC remote out to the Sub Amp and the to 4 ch amp.

Ok awesome! Thank you for taking the time to actually help me visualize the order of operations for these components! That wupp fuse block looks great for the job of getting power/grounding each individual piece of equipment. Only thing I'm wondering is if I could put the proper fuse inside the block itself so I wouldn't have to install an inline fuse. If I did have to run one it'd be fine. I just like to try to keep things as clean as I can. I have an extra 4 gauge in/ 2x 8 gauge out distro block so I could probably run option 2 if you think it'd be smarter. As for the amp in question the guy didn't specify. He just gave a range of any amp that runs 4x 45-75 watts rms to get the job done. Afterwards I'll break out the multimeter to set the gains on everything and try to get them matched up. For the subwoofer he said it's very hard to recognize lower frequencies in relation to time alignment with the front stage. So he said not to worry about that portion.

Now that I think I fully understand how to incorporate all of this into my vehicle my biggest issue is going to be running the speaker wire to each individual driver. I thought this would be the easy part but after my first attempt I noticed I have those molex connectors in the door grommets. After some googling I found that people removed them and just drill through the unused pin in the connectors and ran wire directly through. I don't want to overkill it but I was thinking the 14gauge wire I have is what I would use to wire the speakers. The factory wiring and the wiring coming from the 4ch amp looks so thin. I need to be sure it can fit through the molex connector.

Cross said:

Only thing I'm wondering is if I could put the proper fuse inside the block itself so I wouldn't have to install an inline fuse.

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For the wupp distro block, it comes with some fuses that are pretty close to what you need. It comes with a couple 20, 15, 10, and 5 amp fuses.

Any time you step down a wire gauge from 4 to 8 you need to fuse the wire. If the 8 gauge shorts to ground due some failure you might not pop the fuse installed on the 4 gauge side and burn your car down.

Cross said:

I have an extra 4 gauge in/ 2x 8 gauge out distro block so I could probably run option 2 if you think it'd be smarter

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I wouldn't bother using this unless its fused. I would go with option 1 with a fuse between the distro and subwoofer amp. Unless the subwoofer amp doesn't pull more than 30 amps. I which case everything would just run off the Wupp distro block.

Cross said:

As for the amp in question the guy didn't specify. He just gave a range of any amp that runs 4x 45-75 watts rms to get the job done. Afterwards I'll break out the multimeter to set the gains on everything and try to get them matched up

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Its probably not the best buy for a $200 amp but if you're set on using it than it can work.

Don't bother with the DMM method for setting gains.

Once you get your xovers set on the minidsp for the speaker start playing some music you're familiar with. Starting with both gains at minimum and head unit set to a volume level that doesn't produce distortion (ussually around 90% of full output but might be higher or lower). Start by turning the woofer gain up until you either reach an acceptable output level or start to hear distortion from the mids. It might sound a little strange without hearing the high frequencies playing but you should be able to identify clipping or stresses coming from the driver.

If you want to practice listening for distortion give this test a try. Listen on some headphones or decent speakers.


Next start turn up the gain on the tweeters to level match the mids and highs. These are likely to reach an acceptable output level before you hear distortion because you're trying to level match the mids and highs. If you do hear distortion you're likely using incorrect crossover settings.

Now repeat this process with 3-5 songs and pick a middle of the road setting.

Cross said:

For the subwoofer he said it's very hard to recognize lower frequencies in relation to time alignment with the front stage. So he said not to worry about that portion.

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Actually human hearing below 1000 Hz localizes sound via phase difference rather than level differences. So the TA for mids and subs are fairly important.

What is your subwoofer amp, subwoofer, and enclosure? Where do you plan to install them?

Cross said:

Now that I think I fully understand how to incorporate all of this into my vehicle my biggest issue is going to be running the speaker wire to each individual driver. I thought this would be the easy part but after my first attempt I noticed I have those molex connectors in the door grommets. After some googling I found that people removed them and just drill through the unused pin in the connectors and ran wire directly through. I don't want to overkill it but I was thinking the 14gauge wire I have is what I would use to wire the speakers. The factory wiring and the wiring coming from the 4ch amp looks so thin. I need to be sure it can fit through the molex connector.

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For the power you're running the stock wiring can handle it. If the woofer is the only driver installed in the door you could just use the factory wiring. If your tweeter is also going into the door than you need to run that through the molex plug as you described. 14 gauge is fine, you could have used smaller wire for this amount of power without issue. Folks tend to over size speaker wire a bit. Nothing wrong with that but it makes install a bit inconvenient.

lithium said:

Its probably not the best buy for a $200 amp but if you're set on using it than it can work.

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I could likely return this amp and exchange it if need be.
If it's a negligible difference I wont worry.
I just looked on crutchfield amongst the most popular 4ch amps for my watts needs a went for it.

lithium said:

What is your subwoofer amp, subwoofer, and enclosure? Where do you plan to install them?

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Amp: Amazon.com: Rockford Fosgate R500X1D Prime 1-Channel Class D Amplifier,BLACK: Car Electronics
Subwoofer: Rockford Fosgate Punch P1S4-10
Enclosure: I made my own Frankenstein enclosure so it may not be ideal. I'll attach photos.

I traced a template out behind my wheel well in my trunk and built a layered box using a cnc. I made enough layers to account for the air space but I didn't notice my trunk hinge would interfere with the box. So instead I took out some layers and modified the design and basically attached another box to the original design. The volume inside the 2 boxes equates to the proper airspace but as a DIYer I didn't know if this even would work. I made the box and sub/woofer upgrade over a year ago and I've been very pleased with the bass response. I've always been intimidated to do the door speakers but now I'm looking to learn and be able to accomplish a great all around sounding system.

My woofers are in the door and my tweeters are in the pillars. I'm keeping the stock locations due to the tunes being based on stock. Haven't looked into how to get wire to the tweeters yet but that's for when I'm ready to get into the install. I just figured being that they're wired in parallel I'd have to individually wire them anyways.

Cross said:

I could likely return this amp and exchange it if need be.
If it's a negligible difference I wont worry.
I just looked on crutchfield amongst the most popular 4ch amps for my watts needs a went for it.

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Up until the last weekend the JBL 4086 was on sale for $240 at crutchfield. You can still get it on amazon for that price from JBL.

The kicker key for $240 would take the place of your minidsp and amp. It also has a microphone for auto EQ. Its also a pretty compact size.



You'll be fine with any option including what you have. Pro's and Con's to all these options.

Cross said:

Amp: Amazon.com: Rockford Fosgate R500X1D Prime 1-Channel Class D Amplifier,BLACK: Car Electronics
Subwoofer: Rockford Fosgate Punch P1S4-10
Enclosure: I made my own Frankenstein enclosure so it may not be ideal. I'll attach photos.

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Assuming you ran 4 gauge to the subwoofer amp, I would wire that to the Wupp input and then have a short jumper off that to your subwoofer amp w/ the included external fuse block that you should have installed close to the amp (since the amp doesn't have onboard fusing). Even if you ran 8 gauge you might still be OK with the subwoofer wired to 4 ohm (300 watt) load + the 4 channel amp (400-500 watts on 8 gauge is probably the upper limit).

Cross said:

I traced a template out behind my wheel well in my trunk and built a layered box using a cnc. I made enough layers to account for the air space but I didn't notice my trunk hinge would interfere with the box. So instead I took out some layers and modified the design and basically attached another box to the original design. The volume inside the 2 boxes equates to the proper airspace but as a DIYer I didn't know if this even would work. I made the box and sub/woofer upgrade over a year ago and I've been very pleased with the bass response. I've always been intimidated to do the door speakers but now I'm looking to learn and be able to accomplish a great all around sounding system.

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Enclosure looks great. As long as you get the recommended volume it doesn't really matter what it looks like.

Cross said:

My woofers are in the door and my tweeters are in the pillars. I'm keeping the stock locations due to the tunes being based on stock. Haven't looked into how to get wire to the tweeters yet but that's for when I'm ready to get into the install. I just figured being that they're wired in parallel I'd have to individually wire them anyways.

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Those locations make things a bit easier if you use stock wiring from the HU to the mid in the door; you will have to disconnect the HU wiring for the LOC anyways. Then just run a pair of wires up to the A pillar. Make sure you tape off those factory tweeter wires since they'll be "live".

Or just bite the bullet and run wire into the door. Its a giant pain but you only need to do it once.