jstoner22

iTrader: (1)

i have my doors crossed significantly lower than 150hz and i have never had an issue with any buzzing or rattling.

where else would you have a driver playing 150hz? anything near the rear will really draw attention to it at that frecuency. and next to nothing on the dash will be able to play that low with authority.

matt5112

There comes a point where the sheer sound pressure masks the resonances.

Also what dynamat does is lower the resonant frequency of the panels so it becomes masked by the bass. Clever isnt it... Doesnt actually solve your problem which contributes to distortion none-the-less.

To the post above... do you ever turn the volume past 1?

livesound

Same idea as infinite baffle, using the door as an enclosure or another example would be mounting it with the rear speakers and using the trunk as the enclosure. Not the most popular mount but still an option. The main thing is that there are no leaks from the front to the back of the woofer and its a space saving system.

...all that being said I am planning a dual 8" midbass setup in the front, in small sealed enclosures.

JohnVroom

true

actually lowering the resonant freq may 'solve' (or at least minimize) the issue by avoiding the issue, that is a reasonable solution to move the resonant frequency below the driver range that is exciting the resonance. Also since it is a damping material it will reduce the amplitude of the resonance and its harmonics. Not all solutions in car audio are done as cleanly and simply as a 'properly engineered' solution, true Dynamat it is a bit of a band-aid but the other option may cost a lot of money and be thoroughly impractical . BTW damping material works in recording studios and cost no object stereo rooms quite well

Dynamat or equivalent is a good part of any SQ oriented system, it is a tool in the tool box

matt5112

Recording studios use styrafoam because it actually turns the acoustical engergy into heat.

Last I checked Dynamat wasnt Cornings 70_.

Studios need the destructive room treatments because they need to be able to hear just the music and the mix and nothing else. Not even the speakers can compromise the mix.

But sadly theres still the loudness war somehow...

Real IB = 4 x Vas and a perfect seal.

Its difficult to get either in a car and as such, no one has a real IB and thus has phase issues and defeats the purpose of the IB in the first place.

Using the door as an IB? thats impossible. Unless of course you're mounting say a 2" widerange driver in your door. See above ratio of 4 x Vas. And thats just the minimum of whats considered "worth it" a TRUE IB is 10 x Vas of all the drivers using the enclosure.

Dual 8's as long as they have at least 10 mm of Xmax would make for an excellent midbass solution.

jstoner22

iTrader: (1)

i can have significant volume and not have rattles.
sorry but in my opinion, if your install is such that it "WILL sound bad below 150hz" you are doing something wrong.
masking or not, without dampening=rattles, with=none...i choose with.
if you are talking about just throwing drivers into a stock door sure. but after a decent install, it shouldn't be that that hard to achieve:P

matt5112

Thats ignoring that the driver won't have a proper enclosure.

benny77

you sir, do not realize how a constrained layer damper works.

JohnVroom

NO NO NO Styrofoam is a not a significant absorber of sound and is markedly inferior to other products. it is used for isolation (wall inside a wall) or transition loss maybe and even then there are numerous products that do better, Styrofoam is merely inexpensive and a SUPERIOR thermal insulator. It can function as a transmission loss product but so can any contiguous product, it is simply an inexpensive product approved and expected by construction codes. Damping materials in studio construction are typically used between the finished floor and the sub-floor to limit foot fall sounds and tonal colour.

Of course, I don't know what brought that on and I have no idea what that is about. You can not talk about damping material and bring up fiberglass. They are two wildly different products that do two completely different things (damping vs absorption)

so far your acoustic comments are inaccurate... I am not commenting on other items just the acoustic knowledge

jstoner22

iTrader: (1)

huh?

you stated that anytime you play anything under 150 in a door, it WILL sound bad.
i simply disagree with that statement.



what is the myth up for debate right now anyways? is it me or has it been lost in translation? lol