KeepHopeAlive,

I am new to the art of noise reduction in auto's, and you have mentioned that MLV is a great product to suppress road noise from the floor. Can you tell me what is MLV? And where to get it.

http://soundproofing.org/infopages/flooring.htm, explains what it is, but is there a particular brand you can recommend? My sound system is stock OEM, I am just looking to reduce cabin noise. :-)

Thanks.

 

Hey austinman3214 and keep_hope_alive,

Just a note on the PA amps. Hooked em up, quite dissatisfied with them both.Especially the 1600/4. No way this thing is pumping 150 watts x 4 at 4 ohms/ .o2 thd. It might have hit 60 per channel and that not sounding so clean. The thermal protection circuit kicked in on me after about 20 minutes of maybe slightly over 3/4 power operation. I shut it down for a few then it was fine.
The 1800/2 did a slightly more respectable job of powering the JBL GT-515 but still somewhat lacking. The thing is rated at 700 + watts bridged at 4 ohms. I didn't hear that much power going into that sub. There was also lots of annoying low level hum coming from the sub which they couldn't cure.
So I had ABC pull them and throw in a couple Alpine V-Power amps at 30% off retail and a nice three year warranty, the MRP-M1000 for the sub, and the MRP-F300 for the cabin speaks.
So far the M1000 has been great! At a true 500 watts x 1 @ 4 ohms the bass was considerably deeper, more defined and tighter. The sub really performs nicely on this amp, also no more low freq hum. The amp runs very cool where as the Stax got quite warm after only a few minutes. (I realize the class AB amps run hotter then D's normally)
The MRP-F300 sounds only slightly better then the 1600/4 and alot of that has to do with me upgrading to the Polk coax's up front to match the MM521's in back. I got rid of the Boss coax's up front as one already blew.
The F300 was still not loud enough (50w x 4 @ 4 ohm) and clean enough for me. I am seriously thinking of upgrading to a 100 watt x 4 amp. The PDX Alpine looks very tempting but I am already way over budget. I may go with cheaper power up front but with a CEA rating (I'm learning keep_hope_alive.)
Sorry I didn't have a better report on the Stax austinman3214 but if your ears are happy with your's, they are the only ones that matter.
Blessings all.

 

thanks for the update! no real surprise here, that's the way it goes with Power Acoustik. I can say that i would never put their products in any of my vehicles, even if they paid me.

i have an option for you.

bridge the F300 to the fronts - gives you ~200Wx2 @4 ohm - plenty to get those front Polks singing.

Then you can run the rears off the HU, and get a small amp for them later on.

you want the rear speakers to just provide "fill". think of "rear fill" this way:
when you listen to speakers at home you have them in front of you. all of the sound is directed at you from the front. then sound reflects off the back and side walls - slightly attenuated and filtered based on the absorption of the room/surfaces - those reflections have less energy and are delayed. that is what gives a room a spacious sound. to replicate that in a car you need the rear speakers to be at a lower volume, to be delayed electronically, and to be filtered - typically 250Hz-2kHz bandpass - or just run a midrange driver without the tweeter.

i've never been happy with 50W RMS for my fronts - you end up running the amp too hard - which results in increased distortion. if you bridge the F300 you'll have sooo much more clean power going to them.

I will also say that you shouldn't even mess with coax up front - always component speakers so you can properly locate the tweeter.

 

MLV = Mass Loaded Vinyl

there are many sources for MLV, and it's typically rated 1/8" and 1lb/sq.ft. but you can get thinner and thicker stuff.

finding affordable sources of MLV has taken me quite a bit of searching - and most of the results are on my work computers. It only comes in large rolls and is about $1.50-2.00 per square foot.

MLV alone is not enough - it must be decoupled from the floor - i.e. foam or other material.

Second Skin sells their Luxury Liner and Luxury Liner Pro - both are a MLV with decoupling foam.

You can google these terms/companies:
Acoustical Surfaces INC. (Noise S.T.O.P.)
SoundSense (Noise Out, or Vibramat)
Acoustiblok

what you found is about as cheap as it gets:
http://soundproofing.org/infopages/flooring.htm
http://shop3.mailordercentral.com/su...ber=09-00004-F


In order to be effective - you need 100% coverage. think of sound like water - any hole and it gets in (or out). you want enough to have complete coverage on the floor and transmission hump. you want to ensure the lower A/B/C pillars have coverage, and the firewall. You should also consider the doors as a HUGE noise source. doors benefit from deadener that seals up the holes and creates a cavity - a dead airspace is the best way to block noise. You can also apply a layer of MLV to the doors (front and rear). Road noise is bad at the rear wheel wells - and the trunk is always noisy. I can tell you that the quietest vehicles employ both 100% sound deadening/dampening and MLV.

 

Sounds real good keep_hope_alive, I may just give that a try. Those Alpines are solid! It was them or some Fosgates which I have been very pleased with in the past. Your recommendation on the PDX's swayed me toward Alpine going with V-power which was what they had in stock. Would you say there is a major difference sonically between the PDX series and the MRP series?

 

the PDX is designed to get power in a small footprint at the sacrifice of some sound quality. the MRP should actually sound better - watt for watt. not all people will notice, some will. I think Alpine does a good job all around as an entry level to mid-range company. you can do a lot better, buy you also pay a lot more. Those MRP amps are some of the best bang-for-the-buck amps on the market now. I prefer Alpine amps to Fosgate amps - no real reason why as both are solid.

definitely bridge that amp to your fronts and try it out - should only take about 5 minutes. I do recommend using a DMM to help set gains when bridging or running dual voice coil subs - the DMM will let you get the gains equal - don't rely on the position of the **** alone.

For a slight step up in price - the Hertz Energy Power series of amps are very affordable with good SQ and power output. Hertz also has an awesome line of speakers from entry (Energy) to high end (Mille). Do a search for hertzaudiovideo and you can browse their line - they hail from Italy and have the same parent company as Audison (flat-out awesome amps that i will own someday).

 

Hi keep_hope_alive,

I think I finally found an amp that will be loud enough for me.




http://www.youtube.com/watch?v=Ly3VR...eature=related

 

agreed.

also, Hertz has a 15kW amplifier.

you just need a bank of 300A alternators and a bank of batteries...

 

So Im going to be purchasing some second skin damplier material to stop vibrations in my car. I was just wondering how many sq ft I should get if I wish to apply this stuff to my two coupe doors and trunk. I would rather have extra than too little also haha.

Also is there a site that sells them cheaper than the second skin audio site itself?

Thanks for the time and answers guys.

 

you'll only get Second Skin from the manufacturer, I don't believe Anthony distributes it.

Raammat BXT II is a bit cheaper and just as good as standard Damplifier. No one can match Damplifier Pro.

Bust out your ruler and measure the area of your doors and trunk, then add 25% for curves/bends/etc. You would see a benefit from ~10 sq. ft. per door and 40 sq. ft. for the trunk ~ 60 sq.ft. total.