yup i agree! I see it worthless if you have no EQ to fine tune it to your likings, but its definitely nice if you have an EQ to go along with it.



One thing with an EQ alone that lacks is the ability to boost or cut. On some system, the response may be so low that if you max the boost on the EQ, your overall response for that freq might not be high enough to where you want it at. Same goes with cutting. I can recall a moment where I used the stock headunit in a honda civic hatchback with just an LOC. The resonance of the vehicle was naturally boosted to a high level that even with the EQ at -6db, It was still too peaky. Granted honda probably the lower freq more so the customers will have some bass. lol. I prefer to start with the FR as flat as possible so I don't run into boost/cut problems.

 

It's the EQ's ability to boost/cut that you would buy it for, so I'm not really sure what you mean when you say it lacks that ability.

Second, you can't boost something that isn't there. If a particular frequency range was cut somewhere along the way, even the best EQ is going to have a difficult time making it sound alright... kind of like trying to increase the red in a picture when all you have to work with is a blue and green crayon. Once the red has been heavily removed, that's all she wrote. So, you can't blame the EQ for not being able to accomplish the impossible. But there's nothing to say you can't pick up an EQ with a +/- 12dB boost/cut, or even 24.

I have a tough time imagining a signal that's so peaky in a particular frequency range that couldn't be toned down to soething reasonable with an EQ (unless it was so peaky no one in their right mind would have allowed it to get that way in the first place). Should it happen, though, consider picking up a parametric EQ and set more than one band around the frequency of interest... or buy an EQ with a higher boost/cut figure.

 

Now what if you run into a situation where say 100hz was measured and it was down by 10db? Sure you can use a +/-12db to raise it up to 0db, but most EQ for car on the market have a 1/3rd octave at best. You're going to boost some other freq that was not intented to be boosted. Then again, I prefer to start out with a flat FR as my platform. It makes fine tuning for me much easier. Everyone has their cup of tea though. Unfortunately, the stock headunit's EQ makes it hard for most people to achieve a flat frequency response.

Again, I only see it as a use for stock headunits because of the built in DSP. For aftermarket deck, an EQ alone should be more than adequate.

 

If 100 Hz was already down by 10 dB when it hits the EQ, there's not much hope of recovering it to a normal level. EQs aren't miracle workers... you can't cleanly bring back a signal that has been squashed so heavily. If you're worried about affecting signals arounf 100 Hz, use the parametric as I mentioned before and set the Q to a suitably high value.

 

the stock headunit's EQ may have cut some of the freq low enough that you can't recover with just an external EQ alone. I am willing to bet that alpine, if they are still making s2k decks, lowered the cut by a lot on some freq. This is probably why its hard to boost it to the level you want with just an EQ. Take out the headunit's DSP and essentially you'll have a flatter response. Unfortunately, you can't defeat the DSP that is built in the headunit, which is why JL created the cleansweep.

the onboard DSP is limiting the headunit's potential from having a flat response. the Cleansweep attempts to correct this problem so you can start out fresh with a flat FR.

If the stock deck's EQ cut 100hz down by 10db, it doesn't mean it doesn't exist. It does exist, just that you aren't allowed to boost it up more than you want to. Get rid of the onboard EQ and you'll get close to 0db. Now I fully agree that an EQ will not boost if there was nothing to start with, but the stock headunit does have something to start with..it's just restricted by the EQ.

 

You got it correct with the first paragraph, but then lose it with the final paragraph. The problem with the Clean Sweep is it cannot bypass the onboard EQ/DSP settings of the stock head. Since it cannot bypass it, it can only modify the post-EQ/SP signal. If this post signal has had a frequency range heavily squashed, no amount of processing power is going to be able to return it to a normal level without a serious amount of distortion being added in.

That being said, it's not doing anything a standalone EQ couldn't do for the same money, and at least you have more control over the final output with a standalone EQ. If the cut is so heavy a standalone EQ can't bring it back form the dead, there's not much hope any other piece of $400 equipment is going to have, either.

 

Again, I haven't used this piece of equipment, but I think it could be useful.

Being able to correct the signal before it gets to the other electronics could be pretty useful- car interiors play hell with acoustics. Trying to EQ a car with a troublesome interior for frequency response AND an OEM EQ designed to compensate for shortcomings of the OEM system is a double whammy.

Also, who knows if the aftermarket EQ that you purchase will have the proper center frequencies? I haven't shopped for an EQ lately but I doubt that a 30 band stereo EQ with adjustable Q is going to be inexpensive. And if it is, you still have the issue of tuning the thing. My experience with RTA's and the old Audio Control EQs is that proper tuning is time consuming, quasi-effective as far as eventual results, and that a "flat response" (which is usually no better then +/- 3 db on adjacent EQ bands) sometimes still sounds really bad.

Sure, it could be done, and there is probably a better performing solution than that JL box. But, for the average consumer, to be able to start with a clean signal that is properly matched to the aftermarket amplifiers (no noise, linear volume response, etc) and overcome the OEM EQ, AND provide an AUX input for another source- XM, Sirius, ipod, whatever- without paying an installer big bucks to try to make it all work properly- the JL deal looks like a pretty good solution.

As an added benefit, that unit should easily transfer to another vehicle when it comes time to trade cars.

OEM integration is the wave of the future in the 12V world.

 

the level of integration now disgusts me... i have been known to walk away from considering some cars w/ too much stereo integration.