Rattling/distorting Speakers

[sykikchimp]

I installed MB Quart RSC 216 Component Speakers in front, and MB 4x6 coax in back of my S13.  When I get even somewhat deep base on the front 6 1/2's they begin to distort??  MB Quart claims these speakers are good to 38 hz or some crap.  I have a nakamichi MB-75 6-disk in dash changer pushing the speakers.  No amps.  Any suggestions?

power on Head-unit:  4-channel high power amplifier (40watts x 4) and 4 low-level RCA outputs

[HaLo]

You should try pushing those component with a small amp. &nbsp;My guess is that the distorsion is coming from your head unit, and not the speakers. &nbsp;40wx4 isn't that much power ya know. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=''>

[sykikchimp]

also I thought the crossovers that come with the components would cut out any base the mids couldn't handle. &nbsp;Is that correct? &nbsp;The 4x6's in the back don't distort at all. &nbsp;I have 80hz base blockers on them too,

[DuffMan]

40 watts on a deck is probably arround 15 clean watts in real life. The deck isn't really enough to push those speakers.

[sykikchimp]

thats what I was thinking. &nbsp;Should I buy a 4 channel amp and push all four on it? or should I buy a 2 channel amp and just push the components on it? &nbsp;How big of an amp should I buy? &nbsp;Suggestions? &nbsp;I like SQ not SPL. &nbsp;But I like to listen to my Really clean music LOUD. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>

[200sx]

Yup, those speakers will need a small amp to push them properly. &nbsp;Like Duffman said, the 40w x 4 is only about 15 w. &nbsp;40 watts is PEAK power.. check your specs for your head unit, and look for the RMS wattage. &nbsp;(thats what it will put out normaly) &nbsp;Also.. trying to push high power speakers with low power will hurt them eventually.

[jyt747]

I'd suggest getting a 50x2 amp to power the components. Not a whole lot of power, but it'll sound good. I actually just got the same components as you. Now I'm just waiting for some more money for an amp, probably phoenix gold or something.

[sykikchimp]

btw - specs on the MB Quarts:

Specs: &nbsp;
Impedance: 4 Ohms &nbsp;
Frequency Response: 40-32k &nbsp;
Sensitivity: 86 dB &nbsp;
Power Range: 60-130 watts &nbsp;
Crossover Freq: 3700Hz Hz &nbsp;
Crossover Slope: 12 dB/octave


suggestions on what you would use to push?

[240 2NR]

I'll agree with most people here on the issues of distortion, that you are probably over driving your amp. &nbsp;I would also bet that more speakers have been blown due to running under powered distorted signal, than too much clean power (stock speakers and 1000 watt amps excluded from this bet).

However if you are getting rattling, you may want to look into that since it will only get worse with more power. &nbsp;I had a rattling mounting bracket when i custom fabbed a panel to fit 6.5s in my S13. &nbsp;Ended up taking them out and lining the back of the panel with dynamat. &nbsp;Worked out pretty good. &nbsp;Only rattles at really, really low bass at high volume. &nbsp;The rattle could also be lose cd's in you door pockets or something similar.

[junia]

I agree with everyone but try this first. &nbsp;try swapping out the + and - on one of the front speakers. &nbsp;I've been doing some car stereo work for a while on the side and I've noticed that sometimes having the speakers hooked inphase or out of phase can improve the sound quality. &nbsp;make sure all of the wires for all your speakers are connected correctly too because that could also cause some problems. &nbsp;You don't need a whole lot of power to get good sound quality(but don't expect to be pushing out 20000db's though). &nbsp;I have a pioneer that pushes 50x4max and I'm actually pushing two ten inch subs including my other speakers. no distortions or anything, and I'm actually making my mirrors shake.

[sykikchimp]

I'm pretty sure that I am not pushing enough power to the speakers. &nbsp;I am going to take the door panels off and play them that way and see If I still have the distortion/rattling. &nbsp;I used 1/2" MDF which made it a tight fit under there. &nbsp;If it still rattles and I can rule out rattleing b/w the door and the mdf, then I'm gonna buy an AMP.

Any suggestions on Power and brand of amps for this Application? &nbsp;I'm also gonna be getting 1 or 2 12" Infinity Perfects soon. &nbsp;I'll buy a seperate amp for them though.

[geeaj]

Since your gonna pull it all apart, you may want to check and see if your speaker connections are grounded. Loose connections can cause noise similiar to what you described. Or, your cone could be destroyed due to pumping out high decibels powered by a high distortion head unit.

Also, 40watts a channel is plenty for pushing that 6.5, if the power output has low THD - total harmonic distortion. Most head units are pushing in excess of 1% distortion at x db, which equates to shitty sound. You want THD specs in the .05 range or less. Most head units suck as far as sound quality IMHO>

I am guessing your MB quarts are pretty efficient, i forgot what the technical term was, but I believe SPL is the rating for speaker efficiency. The audio heads can chime in here.

[geeaj]

Sorry, should read your specs. 86db isn't a very efficient speaker, you should pickup a little four channel to power your speakers.

[geeaj]

If you got money to spend, I really like Precision Power or HiFonics for a woofer amp. The PPI's have select a modes so you can run 6/5/4/3/2/1 channel. You can even run a 4 channel mode with a mono sub channel.

I prefer this setup myself...

One amp, lots of options, and not having to worry about wiring in a relay when you have more then two devices activated by remote wire.

[200sx]

Relay? Pardon my ignorance (if it is such) but you can just 'jump' the remote on from amp to amp... as long as it they are good amps, with a soft turn on/off (which MOST amps are these days). &nbsp;I have been wiring up stereos (mine and others) for years... and havn't had a problem doing it this way. &nbsp;The 6/5/4/3/2/1 set up is cool... but I prefer the good old 2 or 4 chanel amps. I fint it easier to wire up/tune the system. &nbsp;One amp for subs, one (or two) for mids and high. &nbsp;As far as A good amp to run those componants, I'd go with the above mentioned, as well as Alpine, Rockford, or Pyramid. &nbsp;That last one was a joke. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>