Audio Upgrades - setting basic config

[t6blo]

With hindsight, I’d have just driven hundreds of miles to one of our resident specialists and paid them, but I’m now too far in having bought stuff myself and am now trying to DIY it to the point where I am satisfied with the sounds vs the money I have spent. I wish I hadn’t even started this now so any tips would be extremely helpful.

Background

I have a Composition Media headunit.

I have run a speaker harness and uncoupled the brown plug from the plug and play loom for the rear camera/canbus - this runs from the headunit to under the passenger seat to carry the F&R L&R high level outputs.

I have a Helix DSP Mini Mk2 > F L&R, R L&R and Sub L&R RCAs > AUDISON SR5.600 amplifier.

I have then run some wires for F L&R from the amplified output back up to the headunit and used pins to plug into the factory loom that then connects to the door speakers.

Door speakers are the Alpine SPC-106T6.

Then I have some Alpine 6x9s in a kick board under the rear bench and these are also powered from the amplified rear outputs.

After being unable to get the rear Wheelarch boxes that I wanted I have bought an Audison Prima APBX DS 10” passive sub enclosure which has yet to be delivered.

Initial Config

Connected an oscilloscope to the FL highlevel output to establish the clipping point for the volume level on the factory headunit.

Even with the volume on max and playing a 0db sine wave, it wasn’t clipping at all.

Q1 - is this likely true or have i not configured the scope correctly?

Next, played the same sine wave with the headunit volume at 3/4 and with the outputs of the DSP muted I adjusted the input gain until the clipping symbol illuminated and then reduced it back down by one level.

With this set I then played correlated pink noise and used the input analyser to look at the wave and made a couple of small adjustments to get it virtually flat.

DSP inputs/outputs are just FL in > Full range > FL out and the same for the other front and rears.
Subwoofers are not yet configured.

The amp is in 5 channel mode and the input gains are all right down and I have not set any crossovers on the amp at all.

Q2. Presumably this should sound at least as good as the factory sound but with a bit more oomph as all four speakers are amplified? I’m getting some distortion to the lower frequencies as I turn up the volume to about halfway.

Issues

The amplifier outputs 4x75w rms but my front Alpines only appear to be 60w rms and the rear 6x9 are only 45w rms.

Q3. When spec’ing this I assume I should have either got a lower power amp or higher wattage speakers - can I reduce the outputs in the DSP or the amp so I am not over powering the speakers or should I be buying new speakers?

Q4. Assume if I don’t turn the volume up too high, then the speakers won’t be over powered or does it not work like that?

Q5. Once I have the subwoofer connected up and have set the crossover for the subwoofer, should I be reducing the amount of lower frequencies that are going into the 4x alpine speakers by setting a crossover in the DSP or leave at full range?

Q6. Is an audio specialist going to want to ‘tune‘ a system that a DIY’er has installed or will they just refuse/laugh?

Thanks in advance for any advice

 

[Stay Frosty]

Sounds like you've got too much test gear there.
You can overpower speakers but not by 10 or 20 watts over the speakers nominal rating.
You don't want to play speakers via a full range output from the amplifier as that's just relying on a passive crossover inline to take out the frequencies below or above the particular speakers resonant frequency/happy zone, daft trying to get a 6" mid in a front door to play below 100Hz or a sub to play above 80Hz.
Using a DSP set up you ideally want to be running fully active with a separate amplifier channel for each speaker so that the head unit can allocate what frequency range each speaker plays and the amplifier simply raises the signal level.

 

[Dav-Tec]

We'd happily tune it. Sure I mentioned this on the phone when we spoke.

It will sound off as it sound like you haven't set any crossovers on your DSP yet.

Always have an amp bigger than speakers not the other way round. It gives you head room.

If you have DSP especially with the Alpines I think you approached it wrong we'd of ran it fully active so the DSP Amp did all the crossovers etc gives you more control and refinement.

Also why have you put speakers you want your ears to listen to near the floor?

Feel free to give me a call to discuss further.

Cheers
Chris
07823449588

 

[Stay Frosty]

@t6blo Looking at the spec of the Audison it shows an input current of 44A with two 25A fuses in parallel as protection, with the best will in the world and really sensitive speakers this is barely going to go much louder than the stock VW setup.
Factor in going from a stock 8" driver in the door to a 6" driver with slightly less excursion and you're not going to be pressurising the cabin quite as much.
I'm sticking with sound pressure level here rather than audio quality as that's normally where a new system shows any improvements but bare in mind you'll need a 10dB raise in SPL in normal use before a system appears to sound twice as loud as the previous system.
On my old car setup which was a collection of gear from the early noughties I ran an active/passive mixture with low level outputs from the Pioneer HU to two Focal 4.75 amps powering the door mids bridged from one amp and the upper mid and tweet on the A pillar via passive crossovers from the other amp.
The sub, an old JL 13W7 was powered from an equally elderly JL 1000/1, there were no rear speakers as it's difficult to get a decent front soundstage when there's deliberate sound smearing going on behind you.
If your front Alpine speakers are fed via the passive crossovers that came with them then you could try hooking up the Audison minus the rear 6x9s and use that output to make a bridged pair to either front side.
If as you say you've used the factory wiring to get into the doors and up to the base of the A pillars then you'll need to cross each driver individually possibly by butchering the Alpine crossovers to feed the highs only to the tweet and mid bass only to the door speakers.

 

[t6blo]

Thanks @Stay Frosty @Dav-Tec

 

[Absolut5]

Totally second what Dav-tec said.

the Audison sr5.600 amp is a great little amp, flexible and great sounding and certainly a lot more powerful than than stock . I wouldn’t bridge the 4 channels and run passive , run them active

 

[t6blo]

Thanks @Absolut5

 

[t6blo]

So, assuming I run some additional speaker wires to the alpine a pillar tweeters and disconnect them from the factory speaker wiring, I would use the Helix DSP to setup the crossovers like this?

Hi level input from headunit Front L and Front R

Output A+B - hi-pass alpine a pillar tweeters
Output C+D - band pass alpine door speakers
Output E+F - low pass audison subwoofers

This would then go via 3 pairs of RCAs to the F, R and Sub SR5.600 inputs?

And it is this point I get confused….. because the amplifier also has a bunch of crossover settings - which I assume I want to ignore and just pass the DSP outputs to the amplifier inputs and ‘pass thru’ to the amplified speaker outputs of the sr5.600?




Do I ignore the crossover settings on the amplifier and have them set at full range?





Or do I just ditch the Helix DSP and use the amplifier high level inputs and inbuilt crossovers?


And what about the rear speakers - understand about them being down too low - I don’t have rear passengers so they are just there for abit of rear fill - using all the channels on the amp for the active front, would it be best to just power the rears from the headunit rear channels or just remove them?

 

[Stay Frosty]

I wouldn't bother with rear speakers as you always end up ruining any sort of front sound stage by smearing the sound and also potentially producing some cancellation at certain frequencies with out of phase sound from the rear pair.
You could do away with the Helix if your head unit has time alignment and just run low level phono leads to the amp but I imagine the Helix will allow you to modify path length differences from the door mids and A pillar tweets to sharpen the front end up and ideally create a decent ball of sound centred between the front seats at ear height.
Try to avoid using high level inputs to any amp as they're inherently noisier.

 

[Dav-Tec]

Don't ditch the DSP. Bypass the crossover on the Audison and let the DSP do the rest

 

[Californication]

So, assuming I run some additional speaker wires to the alpine a pillar tweeters and disconnect them from the factory speaker wiring, I would use the Helix DSP to setup the crossovers like this?

Hi level input from headunit Front L and Front R

Output A+B - hi-pass alpine a pillar tweeters
Output C+D - band pass alpine door speakers
Output E+F - low pass audison subwoofers

This would then go via 3 pairs of RCAs to the F, R and Sub SR5.600 inputs?

And it is this point I get confused….. because the amplifier also has a bunch of crossover settings - which I assume I want to ignore and just pass the DSP outputs to the amplifier inputs and ‘pass thru’ to the amplified speaker outputs of the sr5.600?




Do I ignore the crossover settings on the amplifier and have them set at full range?


View attachment 221169


Or do I just ditch the Helix DSP and use the amplifier high level inputs and inbuilt crossovers?


And what about the rear speakers - understand about them being down too low - I don’t have rear passengers so they are just there for abit of rear fill - using all the channels on the amp for the active front, would it be best to just power the rears from the headunit rear channels or just remove them?

How’s it sounding now ? That’s some great gear!!

Where did you pick up the high level? Clipped/ soldered from back of the head unit ? Thanks!

 

[t6blo]

How’s it sounding now ? That’s some great gear!!

Where did you pick up the high level? Clipped/ soldered from back of the head unit ? Thanks!

I’ve changed it again since these posts !
Removed the Helix DSP and sold it. To my ears it just seemed like overkill.

I am using the high level speaker outputs from the OEM headunit and feeding these directly into the AUDISON amp. Using the adjustments/crossover on the amp to run the Alpine front speakers and two 10” subs at the rear of the van.

I removed the speaker brown multi plug from the quad lock connector and inserted another one with the wires soldered on that run to the amp, then used the opposing pins to plug the amplified wires back into the vehicle loom plug.