Southbound

Great report egilsrud!

I too, slightly scarfed up my first passenger's side sail panel. Because of that, somewhere in all of my ramblings, I mentioned to people to put a piece of protective duct tape over the sail panel down flush to the window before removing the door panel. I did this on my driver's side, and no damage as you wiggle things around to take the panel off and put it back on. Just pull the piece of tape off when you are done. Your method of removing the sail panel would work also, I just didn't want to unsnap anymore things than I had to. You need to protect yourself from damage during the door panel removal as well. Can you remove the sail panel first?

Glad you are happy with the upgrade. The choice to keep the rolloff cap or not is up to the individual ear. However, keep this in mind. When you replace the rears... DO NOT ADD A ROLLOFF CAP back there. (I'm sure you didn't plan to, as it was not specified in my mod process) The 3.9ohm/5watt resistor is just right by itself because the highs aren't as bright by the time they get around the back of the seats. YOU WILL ADD SOME MORE OVERALL BRIGHTNESS TO THE CAR SOUND WHEN YOU REPLACE THE REARS WITH THE POLKS. So, therefore, listen to things for a few weeks after you have replaced all four speakers before removing the rolloff cap up front. But the FINAL choice is up to you.

Another consideration about the Tweeter mod(s)... I don't think You ever heard the Polks installed without the mods, but take it from a lot of us... they are pretty damn bright with the stock EQ. So you find yourself turning down the treble control. But the treble control has a different contour than the EQ box has. Therefore, when you turn the treble down on the HU to the point that the HIGH highs aren't too sibilant and hissy... you have ended up with a hole in the midrange vocal area. You are in a situation there that you can't win... If you keep the complete tweeter mod including the front rolloff cap, then you have an overall tweeter output reduction along with a 6db/octave rolloff that starts with 3db at about 8Khz-10Khz. This additional rolloff was actually added to allow you to now turn the treble back up. Now you can regain the midrange highs without over emphasising the high highs. I spent a lot of time and research coming up with these values... but they are based upon MY ears. Your ears could want slightly different ranges. The nice thing about these DX6s is that you can tweak around with this tweeter arrangement quite easily due to the convenient terminal strip.

My recommended mod values, seem to still sound about right to me. Although after time, I have found that I tend to set the HU controls at plus one or two clicks for the bass, and plus two or three clicks for the treble. Sometimes I think that maybe I'll remove the rolloff cap and see if things sound better now centered... I have gotten used to the crispness and sometimes feel that I wouldn't mind a slightly brighter sound, but I keep remembering through all of my previous listening tests, that the midrange tends to disappear on the Polks when turning down the HU treble. The 4.7uF cap allows you to get the best compromise, IMHO... Feel free to try things with and without the rolloff cap if you wish. Listen to what it does for you with respect to the very highs and the midrange prescense as well. You may find yourself turning down the treble to center without the cap, and then the midrange may become a bit lacking... In any case, WAIT UNTIL YOU REPLACE THE REARS... Everything will come together much better, once you replace them. It's like how when you set the balance to one side... a single speaker sounds like crap, but when you add the second speaker, everything comes together and really recreates the soundstage. This effect will also occur when you get some clarity and some high frequency response coming from the rear fill.

I'm rambling again... Glad to hear that you had success and that you have your terminator caps. Two more Polks in the rear along with the terminator mod improvment, and you will be even more happy. You'll have to keep me posted as to how your bass upgrades progress.

Have a great business trip driving some rental box LOL! It will make the TLS feel and sound sweet when you get back home.

Keep us posted!
Southbound

egilsrud

Hey Southy, you were right about the rental car. It was some Buick POS. On the other hand, it did accelerate fairly decently - I was cruisin' down the 405 in true LA-style...

The Polks from Sound City arrived yesterday. I'll probably install them over the weekend. Goodbye Bose!

I'm entirely happy with the high frequency rolloff mod. I can only imagine how bright the Polks would sound with nothing to roll off the highs...after all, we are replacing full-range speakers with coaxials. I also understand that turning down the highs via the treble control would cut into the midrange as well. In any case, I'm sure that I will regain some highs when the Polks are installed in the back (resistor only, no cap).

Again, THANKS FOR ALL YOUR HELP! You have designed an easy and inexpensive mod that works wonders for the sound.

I've got a Kicker RM-B8 on the way....now I just need to figure out the amp...stay tuned!

egilsrud

I finally removed the last vestige of the Bose speakers on Saturday, and installed the Polks in the rear as well.

Installation went quite well, as I knew what to expect after doing the fronts. In fact, it was easier, as there is only one electrical connector to disconnect. FYI, I used Southbounds terminator mod, and also used a 3.9 ohm 5W resistor inline with the tweeter to drop its output a bit. As was recommended, I didn't add the 4.7 uF caps, so as to "brighten" the sound coming from the back a tad.

I had a bit of a fright when I first powered up the system, and heard only bass from the sub. I figured that I had a short somewhere that was causing the amp in the HU to shut down. I took out both speakers, made sure that the wiring was OK and that there was no potential for any components or wires to short out against the door panel, and the reinstalled. Still no sound! I waited a bit and futzed with some other stuff, and came back to try it again. This time - SUCCESS! Sound from all 4 speakers (and the sub, of course).

I can say that I am truly happy with the sound (especially since I added a new sub - see separate post). The highs and lows are well-balanced: Southbound, you worked magic in figuring out how to counteract the Bose EQ. Most of the time I leave the Bass and Treble flat; sometimes I'll boost the treble one or two clicks.

Being a perfectionist, I occasionally ponder bypassing the HU amp and EQ, and installing a high-powered 4 channel amp. However, I think the cost would be high relative to the improvement in SQ. I would have to pull out the HU and mess with the wiring, potentially inducing warranty issues. Plus, I would probably need to add crossovers (or at least bass blocking caps on the speakers) to reduce the bass going to the Polks, as the Bose EQ takes care of that in my current setup.

For those of you on the fence regarding the Polks - if you can still get your hands on some, DO IT NOW! It's the simplest, most cost-effective change you can make to the stock system.

Whew! That's it. I'm done with my audio mods. Except for the Pioneer XM receiver I saw...gotta have that...must have that...

Southbound

Congrats egilsrud! Another satisfied modified upgrade. You are right in that the saga NEVER ends... You will ALWAYS wonder how much better things could get. I do the same... but I've held off going further (so far) because I can now live with the SQ.

Regarding your "scare" Yeah, somehow you had to have a short on one of the rear wires or terminals. Luckily the headunit self protects itself. I am beginning to think that it also has a high temperature shutdown. If you couldn't locate the source of your short, and things just came back by themselves after waiting for a time period... I would guess that the amp had to cool down before it would let itself power back up. The amp DOES RUN HOT in normal operation. During a short circuit full current foldback mode, it would run extremely hot. This may be what you experienced?

Thanks for the updates and the compliments. Good luck with your subwoofer mods!

Southbound