Well, I've already decided that it's time to move on to the next mod (even tho' I don't have my DX6's installed yet!)

This all started when I read the various postings on the Kicker RMB8. As I researched subs, I ruled out installing a TRUE 8" sub in the factory location (not enough depth available), having a custom sub installation in the trunk (too expensive) or putting a sub box in the trunk (eats up too much space). That leaves me with the Kicker RMB8.

Now for the amp. As I perused the selections in a local audio shop, I noticed the Eclipse 36501 5-channel amp (www.eclipse-web.com). It can pump 40 W into 4 channels at 4 ohms and 120 W into the sub at 4 ohms. Best of all, it has 4 high-level inputs, so I don't have to mess with line output converters, and a separate line-level sub input (can use the standard Bose sub pre-out). I was quoted $379 for the amp.

Installing the amp isn't something I really want to mess with, so I'll have it done by the shop. I'll also replace the factory speaker wires with something decent.

Here's my question (drum roll please): I've looked at the work involved with bypassing the EQ, and frankly, I'm not too comfortable with the idea of taking out my center & rear console etc. If I use the EQ'ed output and feed it into the high-level amp inputs, I will still have the crappy Bose high frequency boost to deal with. Will the high-frequency rolloff mod (3.9 ohm/5 W resistor, 4.7 uF non-polarized electrolytic cap) take the extra power of the amp? 40 watts isn't a huge deal, but I don't want to smell smoke coming out of my doors!

For that matter, will extra power for the door speakers make much of an audible difference from the HU amp? Would I get more "bang for my buck" for installing a mono power amp for the Kicker alone?

Sorry for the long post, but I'm hoping to get something workable here.

Thanks again for all the help! This forum and the people on it are an incredible resource.

 

egilsrud,
I can appreciate your enthusiasm and your impatience to upgrade your system.

However, when dealing with coaxial speakers such as the DX6s, there really are only TWO RIGHT ways to deal with the stock HU and its bogus EQ...

1. If you keep the stock headunit and EQ... Use the Tweeter resistor mod and rolloff cap to deal with the factory EQ boost.

2. If you are installing a new aftermarket amp... TAKE THE TIME TO BYPASS THE BOGUS EQ. The work to remove the center console and dash work, etc. REALLY isn't as bad as it sounds. I was very reluctant to do it as well. Iggy posted some instructions with illustrations from the Helms manual that made the steps clear. I did things very slowly and methodically, but I could do it again in about an hour. Nothing was damaged and everything went back together just fine. Unfortunately, when you bypass the EQ you also lose some gain, which did now allow the stock headunit to produce enough volume. So you can't really go the bypass route with the stock HU and still have full volume... thus the need for the tweeter rolloff mod. But if you have an aftermarket amp to make up for the gain, you would be just fine with the EQ bypassed. This would be the preferred way to go with an additional amp rather than to roll things off with power levels at the speaker. The 5watt resistor would probably get hot, and again, it just wouldn't be the best way to handle the frequency response. It does the trick as a mod for the stock HU, but in theory, it's always better to handle EQ at the line level.

If I were you... I'd install the Polks with the STOCK HEADUNIT AND EQ. You have all the parts to deal with the EQ issue in this mode, so I'd do ALL the mods to the Polks and see how things sound to you.

INSTALL THE TERMINATOR MOD REGARDLESS OF WHICH AMP OR EQ SETUP YOU GO WITH!!! IT HELPS IN ANY CONFIGURATION, AND POWER IS NOT A FACTOR...

If you find that you are not happy with the power level of the stock headunit, then you can re-think installing an aftermarket amp. You (or some shop) will still have to remove ALL of the center console stuff just to get to the wires at the back of the headunit to tap the wires and bypass the EQ. Running new speaker wires to the doors would be a lot more work than taking apart the console to get at the back of the headunit. ALSO, THE TERMINATOR MOD IS DESIGNED TO ELIMINATE THE NEED FOR SPECIAL SPEAKER WIRING! That was why I designed it in the first place. What the terminator mod actually accomplishes is to make common zip cord type wiring look like elaborate high dollar wiring to the amplifier. Running bigger gauge wire would provide very little improvement to the door speakers. They do not have that much power running to them at low frequencies where copper losses are a factor. With the terminator mod installed, I seriously doubt that you could tell the difference between speaker wires blindfolded. Not that it would hurt to upgrade the wiring, but it would be more of a placebo effect than a true audible one. But sometimes just knowing that your system is as good as it can be makes it FEEL better to yourself, and therefore somehow sound better as well.

But I'd say first things first... Stay on the path that you have started. See how things sound after the Polks are installed with all of their mods. If you're still not happy, it's easy enough to remove (or just disconnect) the tweeter rolloff mod when you eventually add another amp. You might be happy with just adding a mono amp and an upgraded subwoofer like the Kicker RMB-8 that you speak of. To be honest... since power is logarithmic, a 40watt amp to the door speakers would really only give you about 3db or 4db more SPL over the stock HU. I can't say that that would be worth all of the extra work and money involved. Try the first step and see how you feel about the system before committing to the next level...

The Polks will BLOW THE BLOSE away and right now that should be your first step. If you still need more (and you might) then you are talking about a complete system upgrade that will require serious work and money. This first step is an EASY and CHEAP upgrade that you can do yourself.

We'll talk again after you've completed phase 1 of upgrading the speakers... Hope I've helped you to put things into perspective rather than to have just confused or discouraged you...

GOOD LUCK!
Southbound

 

You can install the amp and bypass the stock EQ etc. but that would be too much work. Just install the Polks with the roll off mods and get a cheap amp for your RMB8....that is the CHEAPEST, easiest way to go with comparable sound quality to your suggested route....at much lower cost. Try it this way first...if you don't like it, you can always add a more expensive amp and bypass the EQ like u planned later...

 

Thanks for the quick followup Southbound and randomwalk101!

In truth, I was already leaning towards installing the Polks with the high frequency rolloff mod as step 1. Then, if I'm still not completely satisfied, I will consider using an aftermarket amp to drive the Polks. Also, I looked at some of Iggy's posts and realized that getting at the back of the HU isn't as onerous as it sounds.

It would be much less expensive to install a mono power amp for the Kicker than a 5-channel amp, that's fer sure!

 

egilsrud,
Yep that's the ticket... start out with step 1 and see how things sound. Then look into upgrading the subwoofer. If you're still not happy... Well then your only choice is to install an aftermarket amp. In that case go to the work of properly bypassing the EQ and remove the rolloff mod from the Polks. You will probably find yourself in and out of the door panels a few times before things are complete anyway. I've had mine off three times now, and still no harm done... just be slow and careful with your work.

What you could potentially gain from the aftermarket amp to the door speakers, would be the flatter response provided by completely bypassing the EQ unit. Also, the sound quality of every amp is different. So some aftermarket amps COULD sound significanly better than the Pioneer/Acura/Bose headunit. even at the same power levels??? A 40watt aftermarket amp wouldn't give you a lot of extra volume, but it might give you a lot of extra clarity... depends upon the particular amp. I haven't listened to any in the TLS to know how much improvement is there to be had. How much does the stock unit suck? I don't really know... it's that damn EQ that really gets in the way. The headunit does at least have a dynamic limiting circuit that keeps the amp from completely clipping into square waves, and it has proven itself to handle dead shorts several times here on this board. It's definitely a lot easier to keep it... but time will tell if you can live with it. Just remember that what you hear in stores, is not what you'll hear in the car. If I went to the hassle of gutting out the wiring and rewiring everything to an aftermarket amp... I'd make sure that I invested in a REALLY GOOD amp... otherwise the gains will be minimal.

One step at a time... hopefully your .05uF caps arrive soon along with your Polks and you can at least be operating under much better conditions!!!

Hang in there!
Southbound