New info JBL system lower ohms to increase volume

That is exactly what is going on. I just spoke with a cerwin vega rep. And he informed me that it shouldnt work. I told him but it is working and he was excited and told me that if it works then leave it! Also inquired about sounding better to a already sounding good sub in stock enclosure he recommended dynamat or something similar on the inside of the stock enclosure. I have already put a modest amount of polyfill. Not alot. But the wiring is still up in the air on polarity. But heat for sure being inside the stock back wall plastic is definitely too much heat with no airflow. I recorded over 125° this morning pushing the audio system with stock sub at full volume and it was turning down.

 

This is literally a science, the only audio magic this will eventually produce is the release of the magic smoke.

You can't change the rules of a signal clipping, ohms law, polarity etc...

 

Yeah the CV sub does it internal.

Wiring like above will give an 8ohm load. Think higher ohm more resistance and less sound. 8 ohm is like a hallway and 2 ohm like a highway. More current(traffic) can go through. Here's my crude drawing for a 4ohm dvc sub wired to run at 2ohm

 

This is very interesting info about the sub. Do you think just reversing the polarity would produce better results with the stock sub?

Also to combat heat I have an idea of drilling some holes and mounting a 120mm computer fan to push some air around back there.

 

I was in series rather than parallel.

 

Thank you for explaining that. I have a much better understanding of what is being tested now. One last thing would be could improving the quality of the door speakers that seem to be clipping and limiting the system improve the sound and volume without messing with the sub? I am asking more from a stand point of morbid curiosity while also holding my breath hoping that this is the magic sauce we need to get the sound system we deserve in these trucks!

 

They oem sub seems to be running at 4ohm stereo, -/+ of one amp channel to left and the other -/+ amp channel to the right. Bridging creates a 2ohm mono channel. Amp pushes more power single channel. As to why the system itself is louder, maybe it doesn't have as aggressive dsp when it sees a different load applied. Just guessing on that part. Will pull it out tomorrow and play around.

 

Fan like this?

 

Fan

 

Off

 

Dont be confused. All of my testing was done without* a fan but added a fan and left it unhooked to see if it was nessessary

 

It's a dual 2 ohm speaker and according to cerwin vega bridging the amp *if it is even bridging. Witch with this jbl amp I do not think it is! It is still 2 ohms.

 

Exactly!

 

I saw the red and was like holy fuck that's running hot. Fireball coming out the back

 

Polyfill works wonders in that small box. You don't want to, however, put in too much or else it will negate the benefits of it, of course I'm sure you know that.

Dynamat will be difficult to line in there as the surface in there is not only ribbed but the box is too small to put dynamatting in there.

Unfortunately the OE box has some serious size restrictions which does not allow for a whole lot of growth. This stands more true if you run a subwoofer which has a rear venting pole piece (which the majority of better built ones do unless they use direct venting voice coil tech).

You can shave off a good .250 or .300 by knocking down the ribbing back there which will allow you deeper mounting depth, but options are still limited. Full sized subwoofers like the Rockford Fosgate P1 punch SVC 4 ohm or the Polk MM1 4 ohm DVC 8" will fit in there if you knock out the ribbing which the magnet of the sub would bottom out at and actually turn the box (as long as you run polyfill) into a SOLID contender considering it's overall internal cubic volume space, but ultimately, if you are a bass head you will want more out of it and eventually outgrow it as I did.

Moving forward RF no longer makes the P1 SVC in the size I am describing and have increased it's overall mounting depth so it may be difficult to aquire that sub. I will say it sounded pretty darn good back there while I had it and does knock around back there quite well.

Anyone looking to move on from the JBL setup can run a compact monoblock amp to drive the sub independently back there, which is how I was running my setup before changing out the OE setup.

What are you using the fan for?

 

Fan was first installed as a thought that the amp being buried behind the plastic was the culprit for the auto volume decrease. Since I had the back plastic off I tinkered with the sub and just ordered the pioneer shallow dual 2 ohm sub. Stock sub hit harder at low volume. Pioneer hit cleaner at high volume. But that didnt help by turning the volume up to hear the new sub the car turned town the volume rendering the new sub useless. The cerwin vega was alot more sensitive to the minimal output of the factory amp. And the wiring seemed to help channeling the power somehow* into the sub witch produced alot more output. Including the minimal polyfill. From what I learned today. That amp NEEDS a exterior form of ventilation or cooling. It is not a question. I got temps about 130 ° today and it started turning down. Hooking the fan up the amp was down to 98° in a couple minutes and full volume restored. I haven't had time to mess with the wiring too much yet. But I drove home from work and wanted to keep pushing the amp for testing purposes and simply had to turn it down. It was just too loud. So inferior sub and overheating amp. Door speakers and tweeters seem pretty legit and holding up well listening to edm and electro bass tracks honestly abusing them as hard as I can with the thought if they break they were already destined for the garbage can anyway.

 

My last hobby included use of minature fans. I am sort of a expert among my friends. If anyone has any questions about fans. I can most likely help

 

Okay wire selection and polarity. I just tried pioneer TS-SW2002D2 wired to 1 ohm and it did not work. It worked for a minute then the amp just turned off. So 1 ohm is out. But..... It DID make the door speakers louder/distort couldnt tell too much cuz it cut off. So the system IS integrated and not separate channels like a traditional amplifier. This sub is not as powerful as the cerwin vegas V84Dv2. And the sensitivity is rated 86 and cerwin 82. So open air testing with android bass pad app. Cerwin vega easy winner. Now concerning the wires. I tried every combination and the black wire seems to be almost useless so if you are wiring subs that have 1 input set of terminals the red ground and the green positive are easily herd over any other combination. Now I said earlier that the sub sounded better in reverse polarity. Well just testing now at low volume it seems that wired green to positive and red to negative (normal polarity) seems to work best! Barely, at low volume. As for heat. With the back plastic off I haven't had and audible automatic volume decreasing. Volume stays as loud as when you first turn on your truck. Taking into account ambient is around 85°. When I am not in the truck I always catch myself thinking about upgrading the whole system then when I'm driving in the truck listening I feel it sounds so good that i would probably regret doing so. XM radio is not as impressive as BT audio. And BT audio is more or less dictated by the source. If you have a audio setting or dsp on your phone. Play with the settings. I have a samsung S10 5g and have mine set to Dolby digital (normal) and has my speakers to the point of distortion with **spotify set to high resolution playback** It's incredibly clear and powerful. XM is still good but could use a small boost.

 

3 subs.

 

The stock box is 0.60 cubic feet