First, let me start by saying I love my Mustang. It is my 3rd. Anyways, I have all the basic bolt on: mass air, 70mm tb, upper/lower manifold, Steeda cam, bassani headers and x-pipe. I had Flower Master mufflers with dumps and it was way too loud and at 2,000 rpm's the car would shake. It was great for setting off car alarms...problem was it was all the time.
So I switched to Edelbrock's SDT(Sound Deflection Technology) mufflers with 2 1/2 tailpipes and much better. I understand it's a Mustang and when I step on it I want to hear it, but not so when under daily easy driving.
I would really like to get the rumble or resonace down to a minimum. Any recommendations on quiteing exhaust. For now I just purchased audio damping matting to install around the car.

What else can I do to reduce this? Sound(resonace) really kicks in from 1,900 rpm to 2,200 rpm.
Has anyone tried sound damping cones(behind the headers or end of the tailpipes)? I seen them for sale but do not know of anyone using them.

I know that dudes who run turbos sound much more quite but I am looking for a cheap and easy fix to this problem.

Any help or ideas would be great.

 

just buy electric cut outs. go from dumps to tails in a few seconds. the cones will probably hurt performance but you can sure try them. i use to run dumps too, just gets kind of annoying when its all the time. i enjoy my tails since its still loud to everyone outside of the car

 

Right. I got ride of the dumps and running 2 1/2 tailpipes now. Big help, just looking to do something more if possible. Thanks!!!

 

Does anybody know of the quitest sounding mufflers besides from the stock mufflers?

 

I had magnaflow on my old camaro(dont shoot me mustang fanboys!) going to stock manifolds and i loved them.. At idle, it had a nice little rumble like any v8 should have and if you drive easy and calm.. it wasnt loud at all.. What i really liked about them is when if you go hard on the gas pedal.. it awakes a beast and it sounds so nice. Im going to slap magnaflows on my new mustang when i get some money.. The flowmasters on it are nice but i dont want half the city looking at me driving calming and having it sound like i have 800hp under the hood when i only have about 200.. lol

 

keep your cats on, that'll muffle it some....

as for mufflers, I dunno, my mac catback is loud, but not hugely loud.... but everything seems louder in a convertible, roof up or down

 

I have no cats. I am sure that adds to the volume. Really dont want to put them on for now. Way expensive.

 

i have cherry bomb extreme mufflers. DAMN do i love these things. they are the short little 1 chamber mufflers, not glass packs. they're quiet with a good rumble at idle and when cruising, but if i lay into the gas they'll scream their A$$'s off, i also have an off-road pipe.
i've had 03-04 cobra owners come up to me and ask me what i have on my motor and i can still say i'm stock cause there has been no work done what so ever, they dont believe me and i pop my hood. then i tell em the exhaust i have and how much it ran me and their jaws drop haha. all in all my exhaust with the o/r pipe and the mufflers w/install ended up costing about 270 bucks

 

Get some hi-flow cats for the Bassani X...

 

slp makes a muffler called the superflow or its the power flow, its a straight through design but has a lot of packing inside and is pretty quiet and you won't hurt performance. they are a little pricy though