Wondering if anyone can help me troubleshoot my sound system. I have a KDC-MP8017 HU and 4 coax Nakamichi speakers, running off a 5ch Alpine amp. Also a sub in the trunk.
The problem is that I am not getting almost any bass from the 4 speakers. After I put an amp in they sound much brighter and cleaner, but there is still no bass. Even my stock setup on Honda Accord had way more bass to the speakers... Do you guys have any ideas what could be wrong? They are suppose to be good quality speakers... I don't think it's the amp since I had the same problem prior to having it installed. Could the HU not be installed incorrectly?
Thanks

 

When you say you're not getting any bass...

what kind of frequencies are you talking about? Do they produce normal rock-guitar range midbass OK? Do the cones of the speakers move when music is played at a normal volume? Can you feel vibration travelling through the door panels (if you're not extremely dynamatted up) during musical (ala rock, light rock, classical, jazz, etc) songs with a lot of midbass present?

The frequency response of the current model Nak 6.5 coax's start at 70Hz. I haven't personally heard the nak's but given their reputation, I'd say they're pretty sound-quality emphasized.

If you're listening to a lot of rap or techno with a lot of low-frequency bass, they're not going to do a whole lot on that, I'm guessing. Their strong range should be the midbass range, not necessarily around 70-100Hz.

But if you aren't even getting good midbass reproduction, there could be a problem. Perhaps reversed polarity, although this usually happens by accident on one speaker and not a set of 4. Another problem could be how the speakers are mounted. Are they flush & sealed with no air coming out around the edges? Did you use the stock speaker pods, or do you have custom enclosures? Also, how did you wire them up to the amp? Aftermarket shielded speaker wire directly running to the amp?

Some 6.5 two/three-ways are more geared towards just producing lower-end bass, usually ones that don't have very good sound quality. These days, I seem to notice stock paper cones in a lot of cars are kind of aimed at producing lower frequency bass and not necessarily midrange. This could be why the accord's system seems to have "bumped" a little more - I'm sure the Nak's are 1000 leagues better in terms of sq though. The eclipses I have in my sig's freq response start at 90Hz - they don't match the stock bose paper cone woofers for low-end, but they don't distort nearly as easily, adn the sq is much better than the bose, even going from tweets & woofers to coaxs.

 

More than likely your crossover on the amp is set too high and the lower frequencies are being cut off. Check and see where your crossover frequency is. If it is in the 200 and up range, turn it down!! It should be around 120 or so. Then you will get more of the bass you are looking for in your interior speakers. Hope this helps!