Dynamat Poll, yes or no? If so how much?

please post that email

 

isn't there frost king insulation at Lowe's that works just as well as any deading material? I remember reading it on a thread here..

 

Well my lesson learned is that I may have thread jacked, lol. And that most noticeable noise reduction will be heard while parked. That the Tacoma has wind noise problems, probably from the glass and door seals meaning that this mod may also help (http://www.tacomaworld.com/forum/2nd-gen-tacomas/57536-soundproofing-wind-noise.html) and lastly I may not have to put as much funds into this as originally planned.

 

Sorry StZu for the delay in posting the email....

---- Steven Solazzo <steven@stereoclarity.com> wrote:
It's actually a very significant difference. It's hard to see that unless you really understand the decibel system though. I'm happy to explain it though.

Much like the Richter Scale, the decibel system is a logarithmic scale meaning it's based on the logarithm of the unit itself. Lost story short each decibel is not an actual unit of measure. So the difference between 39 and 40db is not the same as the difference between 119 and 120db. In fact, the difference between 119 and 120db is SIGNIFICANTLY higher.

I'll try and apply this in a meaningful way. If one speaker on 100 watts creates a sound that is 100db loud how loud do you think two speakers each getting 100 watts would be? You'd think it would be 200db since there are twice the number of speakers but that's actually not right. The sound of both speakers would only be 3db louder!

Check out this picture from the link. It definitely helps put things in perspective.
http://upload.wikimedia.org/wikipedia/en/thumb/a/a0/X_and_log_x.svg/214px-X_and_log_x.svg.png

The general rules of thumb with speakers is that you can gain 3db by doubling the number of speakers or doubling the power to the single speaker. Think about that, the speaker making 100db on 100watts will only yield 103db on 200watts. Crazy isn't it?

It's kinda like automotive 1/4 mile drag racing. A tenth of a second when racing 16 second civics down the strip isn't a large win margin and the physical gap between cars is very small. But when top fuel dragsters are running 5 second 1/4 mile times a tenth of a second is a HUGE margin and could be bus lengths!

Now go back and look at the numbers we posted. [?]
Steven Solazzo Founder and Owner
www.StereoClarity.com

Thanks Steven for the education.... I hope there's not a test!?

 

nice explanation Steven. And thanks for posting this email.

 

You're welcome guys. Hopefully that helps put the numbers in perspective.

And I agree with Mark, the most noticable difference will be when parked since the huge amount of wind noise enters from areas not treated by noise products. The good news for me though is that SQ judges like the car to be parked.

 

Thats a 6db increase... 3db for twice the number of speakers at 100 watts total and 3 db for twice the power 200 wats vs 100 watts.

 

You're exactly right, I must have been half asleep when I wrote that. Hopefully someone can edit that post.

Just doubling the number of speakers doubles the cone area which increases the efficiency of the whole system yielding 3db. If the power were to double on the subs and each got it's own 100 watts (for 200 total) it would yield +6db.

Which brings up an interesting topic as well. If you're running an amp at 4 ohms or something and it's stable at 2 adding another sub and wiring it in parallel will give you a very loud increase in SPL. It's a win win situation.

 

do it yourself and save some $'s.

 

Also not always true. I am getting a JL HD900/5 amp... it runs 4x100 at 4 ohms and 1x500 at 4 ohms. At 2 Ohms it runs 75x4 watts and the sub channel does 1.5-5 Ohms at 500 watts. Its specifically calibrated to run at 4 ohms for sound quality and overall performance.

IMO its the best amp for a system in a Tacoma if the power needs suit you and you dont mind the price tag ($600-750 depending on where you buy). It uses much less power than many traditionl dual amp set ups with an A/B for the highs and older Class D for the sub. Better sound quality and lower noise floor than PDX5 or Zed Leviathan.

Also, decreasing the resistance (ohms) decreases the damping factor and decreases sound quality. It also decreses the effeicieny of your amp as more power is lost to heat. Decreasing ohms is not "free" extra power.

 

going from 100 watts going to 1 sub to 200 watts going to 2 separate subs, 100 watts each, is a 3db gain

 

Of course. Amps like the JL with RIPPS and the PDX series are a nice little exception.

I run the JL in my Tacoma for those reasons as well. I don't think anyone here will really notice the change in dampening factor though. You also left out that every time the impedance is halved you double the distortion. It's likely to be inaudible on most normal systems.

It was a nice touch though that the JL makes 500 at 4ohms. I'd gone from running those Tang Bands at 1ohm on another amp (which was wonderful) and now I can raise it to 4.

I don't believe so. Try modeling some subwoofers like I've done in Unibox. As you can see from the data, two subs results in the efficiency of the system going up 3db. (top middle column) When you graph the results and throw 200watts at the system instead of 100 on a single sub you gain 6db.

 

that messed up, although there are many variables there that could cause the extra gain.

 

Pretty crazy right?

And I think it goes without saying that when we talk about 3db or 6db gains it's approximate and not an exact value. It should be close though.

 

I was thinking of some Dynamat just to cut down on the road noise. How'd this turn out for you?

 

I've seen it done a couple time, works great but takes a lot of Dynamat

 

If you're looking to block road noise the proper material to use is Mass Loaded Vinyl. Dynamat is for resonances.

 

Is closed cell foam horrible at reducing road noise vs mass loaded vinyl? Id prefer to keep weight down and not just throw weight at the noise issue which is the standard, easy cure. My concern is primarily mud tire road noise.

 

Yes, foam wont do much. You don't have to add too much weight though. I did the whole truck and added 55lbs of MLV....and that was the WHOLE truck and all 4 doors.

 

It's pretty heavy stuff man not gonna lie. If you like it though then that's on you. It helps A TON with road noises. It's ridiculous how quite it gets. I've been inside a lexus is300 with all of it on and without. Huge difference.