Brandon Steck

Hey all. I've been having this problem for almost a year, but it's tax time and if I have to replace something I'll have some money, so I've just started going after it aggressively. Right now I have an Eclipse 5423 HU, Diamond Audio s600s component speakers run off of a 600x2 amp (I'm not that worried about the rears as far as this is concerned). I also have an Eclipse equalizer. Here's the deal. In my old car, a 2001 Honda Prelude, I had basically the same setup except the amp was an Eclipse amp only pushing about 85w. It sounded amazing, it put others with much more expensive systems to shame. Clean and crisp up to the max volume setting. Now that I have essentially the same thing in my 350z it sounds . . . not so good. No matter what adjustments I make on the equalizer, the amp, and the head unit, there is a section of frequencies that are MUCH louder and harsher than the rest. More specifically, it's the higher mid and lower high range, if you get what I'm saying. For some reason, even with these frequencies all the way down on the EQ, they are shouting to no end. My friend is an installer at Best Buy, so he and I took the crossovers out of the doors and messed with turning the settings down on that. No luck. The only changes to be made are to lower the tweeter between +2, 0, and -2 db. They're currently on -2. So what we did was we took a pair of Kenwood components with their own crossovers and hooked them up to the amp to see if it was the speakers or something else. The Kenwoods, while a much lower quality speaker, still exhibited the same thing. Overall smootness on low mids and high highs, but the area in between was noticeably dominating the rest. For example, U2's With or Without you . . . about a minute into the song there's a whistle type noise that's in the background. This whistle is absolutely piercing. Also, Bono's voice, when he gets into his higher range, is piercing as well. Another example . . . in Breakfast at Tiffany's (kind of a fruity song, but good for tests), it sounded excellent, but when the chorus came in and there's a lot of that upper middle range, it's awful. Anyway, the Kenwoods had the same problem. So now we're down to, it's the amp or it's the head unit. The head unit does not offer a terrible amount of adjustments. It's pretty much limited to a high and sub crossover, as well as a frequency setting for the treble and bass. Both do nothing to help the problem. For this reason, I'm thinking it's the head unit. I don't think the amp, since its primary function is power, would have much to do with this, am I right? We tried the settings for the high pass but to no avail. I've talked to Diamond customer service and I have the high pass at their recommended setting. This brings me back to the head unit. The only thing I'm having a hard time with is that I had the same head unit in my Prelude and it was perfect. My girlfriend, who went from an '01 Civic to an '04 Spec V is having the same problem, except her system is the EXACT same equipment that was pulled out of her Civic and put into her Sentra, basically the same equipement as me except with a Rockford amp. Sounded great in the Civic, terrible in the Sentra. I know imaging definitely plays a part in building a system, but these are $500 a pair speakers. There's no way they should sound like this. Anyway . . . please help!!

Brandon

Dean_S

So what changed between the two systems??? For your description it sounds like the amp and the installation. Installation does matter but I don't think that's your problem. You don't what the 600x2 amp is but I wonder if it's just not good compared to the Eclipse you had previously.

Jason Fulton

Maybe toy with the x-overs on the amp? Otherwise it is most likely in the install. Where are the tweets mounted? All cars are different and theres a good chance that z may like something different. If its too harsh reflect them off the windshield. You should not be eq'ing yet when you are having this many problems. Another reason for having more midbass reponse is because the z door may be more sealed off and a much better home for the IB mid, where as hondas have jack shit for deadening in doors (i've got a civic, it blew until i deadened it). My advice would be to pop the tweets out, pull out the double sided tape or sticky tack and experiment with the tweets in different places. I find it very hard to believe that this is an equipment problem. But what kind of amp is it? and I'm going to assume that the 600x2 is a max rating (which means nothing).

One other thing is make sure you completely fade out the rear speakers, rear fill typically just messes things up, and troubleshooting comps will be very difficult with them. Turn of your sub as well.

eddie-M

Check the gains on the amp, sometimes reversing polarity on the tweets softens the image. Install is very important. So dont assume your 600 dollar speakers are going to sound good if you dont do the install properly. Also the crossover setting should be at highest 80Hz, where are the speakers located, door, kicks, a pillar?

Listen with your ears and not your eyes.

Brandon Steck

I've adjusted everything possible on the amp. I went to Sound Advice last night and ended up walking out with an Alpine cda-9835. I think my problem is with my head unit, so I figured I'd try a new one. Sound Advice's return policy is 60 days, even if they don't install it, which is pretty sweet. The guy I talked to was very accommodating. I usually feel bad if I buy something and they know there's a good chance of me returning it if it doesn't work how I want, but the guy just said if it doesn't do what I want it to, bring it back. So that was good. I'm hoping this will put an end to all this BS, plus it's a pretty cool head unit, so if it works I'll be ecstatic. From the reviews out there, I don't think I could find a better HU. This thing has mad adjustments, and the ipersonalize feature grabbed me. The ipod support is a good feature also, even though I don't have an ipod for now.

imported_Dave Bronsveld

My experience is that freq resp problems like you describe are usually caused by cancellations caused by reflecting sound.

Different cars have different shapes and so the same speakers can sound very different. Many cars bounce the sound around in the foot-well resulting in a terrible looking response curve.

You might want to take the car to a shop with a RTA and check to see what's happening. Instead of a straight line, your chart might look like sawteeth due to "comb-filtering" - sections of the freq spectrum alternately accentuated, and diminished.

Some things you might try... Double check your polarity on all the speakers - make sure they are all in phase.

Mount your tweeter as close to the mid-woofer as possible. Also, make sure the mid-woofers have a nice sturdy mounting surface. Try a different location. Sometimes a steeper slope crossover can help.

Good luck....some cars are tough...

Aaron Howell

Sounds like the midrange is out of phase. Very common in cars....

If you have bought a alpine 9835, there isn't much stopping you from going active and ditching those passive networks.