WDPinit

Quite confused with how to "tune" my amp, a Rockford Fosgate Prime R500X1D. It's powering a pair of 12 RF P1s in a ported box. Tried tuning this on my own, but haven't had much luck. They sound like crap and I can barely even hear my music (gain is at 5 btw). If anyone could help me with some tips on tuning the amp so it sounds better and not like a giant fart I'd really appreciate it. Here's a pic of the amp:

cyberquest

typically you want to turn your head unit to 75% of its full volume, anything above that and your going to get a bunch of distortion. once you find your 75% volume range then start tuning the amp to match.. its best to turn the low pass crossover on so it filters out any frequency above a certain point, i usually set mine on 80hz so it will only play tones below that and it filters out all the highs. then slowly bring the gain control up until you hear distortion from the subs then back it down just a hair.

SMD (steve meade designs) actually sells a tool to help you set the gain on the amp and it retails for around $150. a little pricey if your just setting up one amp but if your like me and are always installing them in different cars and installing for my buddies its a very useful tool.

WDPinit

Thanks a lot! I have the same amp, but it is powering an Infinity Kappa 12 now! The sub is 350W RMS but Crutch field says it will take 500W just fine. I tried doing a little tuning yesterday on my own, but the directions you gave are much better than what I had lol. What exactly is this distrotion going to sound like? Under powering is clipping and overpowering is a bad banging sound from the sub hitting too hard apparently?? Also, is it best to have my trunk wide open for this or will that hinder the sound?

cyberquest

distortion is more the sound of the sub hitting too hard in a sense, it will go from a crisp sound to having a not so crisp sound. you can have your trunk open because your listening to the sub itself, if you can stand it i typically have my ear pretty close to the sub so i can hear when the sound from it changes while turning up the amp.

Rockford Fosgate is one of my favorite companies for amps (Mb Quart is another) but rockford rates the power of their amps a little differently then most companies. your amp is rated at 500x1 @ 2ohms but they also rate it with what they call Dynamic Power and that rating is 647 Watts x 1 @ 2-Ohms 0° Res. and 333 watts @ 4-ohms.
R500X1D - Prime 500 Watt Class-D Mono Amplifier | Rockford Fosgate®

do you know if your sub is running at 2 or 4 ohms? to get the full power from the amp your sub would need to be running at 2 ohms.

WDPinit

Is dynamic powe just their way of saying peak power? And yes the Kappa is at 2 ohms. It actually has a switch you flip for 2 or 4 ohms. Honestly, I think I'm just being super sensitive to trunk rattles and it's distracting me. I dont see how 500W with gains at 4/10 and no bass boost could distort this thing. Also, do you prefer your ski pass open or closed?

cyberquest

after a little reading i think you may be correct on the dynamic power, just another way of saying peak power or non-constant power.

there is also a way to set the gain on a amp using a multi-meter to set the gain on your amp and i have used this method before. you basically take the wattage of your amp and multiply it by the ohms its running at. so your amp is a 500 watt amp running at 2ohms so thats 1000 watts, then you divide that by the square root which would be 31.62 volts. you basically disconnect the subwoofer and turn your head unit to its 75% volume level and hook the volt meter up to the positive and negative leads of the amp that go to the speaker and turn your gain up until your meter is reading the 31.62v and thats supposed to be roughly the point of where it reaches distortion.

one thing you want to make sure is if your head unit has a built in crossover that you can set you dont want to use it and the amp crossover at the same time. if you have your head unit crossover set to 80hz then you want to turn off the amp crossover or turn it up all the way, or if you have the amp crossover set to 80hz then you want to turn off the head unit crossover. you may also try setting your crossover to a little lower setting like 60hz and it may clear up some of the distortion to your liking. i typically set my sub amp to 80hz then use the HPF (high pass filter) on the head unit for the door speakers to 80hz. that way the door speakers are playing tones above 80hz and the sub is playing notes below 80hz that way you get a full range of tones.

and i am not sure what you mean by "ski pass"

WDPinit

Thanks for all the help! I have been able to set everything better and it turns out my low pass was set too high and I had read the numbers on it wrong earlier lol. Big improvement! Sounds clean and it hits quite hard for sealed.

cyberquest

awesome, glad i could be of help. .happy bumping.

Bchester6

If you have a slope switch (12db, 24db) you may want to mess around with it as well. When you have matched 80hz x-over points as stated above sometimes notes become muddy,due to overlapping and cabin gain, and lose definition esp. if your sub amp is set to a 12db slope. I highly recommend using a 24db slope if this is the point you wish to crossover at but it is all up to you the listener.

WDPinit

Sorry, I just saw this lol. Anyway, my amp doesn't have a slope switch. My line out converter is nothing fancy either, just a PAC. The LOC is connected at the factory sub as well. I don't know if sound quality is suffering greatly from those factors lol. Do you think trunk rattles are hurting sq that much? This is a sealed Infinity Kappa, so I'm definitely being more picky with sound compared to my ported RF P1 Punches. It's odd, rock and those rap songs that go real low sound sound pretty good, but a lot of techno and other rap doesn't sound too swift.

cyberquest

well there is your problem.....your listening to techno.....lol.

tapping into the subwoofer may be causing some of the unwanted sound since the factory amp is already using a crossover of some sort. tapping into the rear speakers may yield better sound quality. i have used the cheap pac models before and havent had any problems with them.

Bchester6

I think most people elect rear speaker wires because it's a full range signal that passes through. Subwoofer wire is only an option if you can grab it pre-amp, provided your amp can process the balanced signal successfully. The amp in this thread cannot so there you go. I have had great success with Audiocontrol stuff as it has bass restoration that helps compensate for the dreaded factory "roll off" on their subwoofers.

Toyang90

Hi

WDPinit

So you you think if I spend what $90 or $100 on an Audio control loc I'll be able to get rid of that roll off? I'm not quite sure where the loc is tapped in at, but I just assumed the factory sub when I was stuffing stuff under the rear deck for rattles hoping it'd help. Also, I assumed so because I can control sub volume from the factory head unit. If a different LOC will fix the roll off maybe I should go for that instead of deadening my trunk? Btw you and Cyberquest have been a great help so far

WDPinit

Wait if I sent a pic could you guys tell where it's tapped in? Could I easily have the signal changed to the rear speakers if it's at the sub?

Bchester6

Just find the post-amp wiring schematic for your car and match it up. Deadening your trunk still needs to happen bro...

WDPinit

Haha I'll get to deadener soon. This will just help with the roll off for now. Now when I tap in at the rear speakers, is sub volume controlled by the fader option now? I really don't want the rear speakers up too much considering that I have aftermarket comps up front.

Bchester6

If that's the route you decide a Bass knob is your best bet. RF has a module

WDPinit

I have considered a bass knob in the past. I actually turned down the gain a bit and the lpf I set just a tiny bit lower, and then opened up the ski pass (middle seat) and it sounds better because I guess not as much bass is bouncing off the trunk. Btw, is going infinite baffle hard to setup? I think this sub would do well if I went with a smaller amp ofc

Bchester6

Infinite baffle isn't a problem... finding a subwoofer is going to be the challenge. Not many can perform up to expectation as it is typically the third option after sealed and ported enclosures. I know of only an experienced few that have actually pulled one off. If I were you I would start with sound deadening and if you still aren't satisfied then upgrade your equipment. Your system is only as good as it components...

cyberquest

the last sub box i built was a Labyrinth box and i was amazed at the sound it produced. the labyrinth allows long low frequency sound waves to easily escape while short high frequency waves remain trapped unable to cause unwanted cancellation and distortion. the only problem with a labyrinth box is that they are rather large because of the long port design.

here is the one i made using a single Skar Audio 8" MA subwoofer. the box was 30" wide, 16" deep, and 10" tall and this is the size needed for just a single 8" box so one needed for a 12" sub would be very large. but the sound quality is amazing. this box was intended for a hatchback car where a ported box will sound the best, i am not sure how well it would work in a trunk.




here is another box i built for my daily driver for a single 12" American Bass sub, this is a L Slot box, just picture the Labyrinth box without the center piece of wood. its sitting in the back of the same style car as the one pictured above just a different car but the hatch is exactly the same. notice the size difference in the box for the 12" sub, for this box to be a Labyrinth box it would be much larger.

Bchester6

Those do produce amazing sound quality but the amount of space needed to make one is insane. My buddy had a single 12" JL (don't know model or version) and the thing took up his entire cargo area, no shit. Awesome in many ways but 4th option probably.

cyberquest

i am curious how many Cubic Feet his box is, having too little of airspace for the sub could be causing some of the problem also. according to the specs of the Kappa 12" it requires .9cf of space and its saying thats taking the speakers displacement in to account. so if the box uses 3/4" wood it would need to be 12x12x15.75 to have .909cf of space, if its 5/8 thick wood then it would need to be 12x12x15.25 to have .912cf.

to me even for a sealed box that seams like very little airspace especially if you wanted a more boomy sound from the box. its calling for 2.5cf for a ported box again its taking speaker displacement and port volume into account, they say to use a 4" port thats 10" in length. the 12" American Bass sub box i have pictured has 3.5cf of space and has a much larger port tuned to 32hz.

WDPinit

It's a 1.0 Cuft box with polyfill. I think it actually has a fair amount of boom to it. I went with sealed as opposed to ported because I wanted to try a tighter sound and for the sub to be able to handle more power as I didn't feel like buying a new amp. On certain songs, this thing can really get the mirror to shake on those low notes, but I feel like the 35-50hz range could do to sound a little better with rap and electronic. This is probably because I get the most rattles in this range. I am not looking to spend a lot on deadening and I found 20 sq ft of NVX deadening for a trunk kit on SonicElectronix. It is thicker than Dynamat Extreme and only costs $55! You really can't beat that price and it has a 4.9 review. If you want to see my box in a pic let me know.

cyberquest

pics never hurt i would be interested to see how much space the box takes up. i am pretty happy with the factory sound system which is not like me, normally i like to rattle the windows but i guess the Acura has more of a luxury car feel to it and it doesnt feel like the type of car to have a crazy system in. i do have plenty of stereo equipment laying around though and may do i single 8" later down the road.

with only 1cf of space your going to get the desired tighter bass you want, but like your experiencing the lower tones are going to lack a little bit. the polyfill does help "trick" the sub into thinking there is more airspace though.

WDPinit

I your opinion on the whole luxury thing and not wanting an all out system is because you have an RL which is on the nicer end of the spectrum. I see my TL as a good mix of sportiness and luxury. I would imagine the factory system in the RL sounds better due to nicer stock components and more factory sound deadening for a quieter drive. I'm pretty young, so I like a lot of bass, but I do want it clean sounding. I could never go with an 8 since they usually don't get too low. Also, the funny thing about my sub is that it may lack at times in the 35-50 hz range, but those notes at 35 hz and under actually come out surprisingly well for sealed! I have used test tones and have gotten it to hit like 24 hz or so. Once I get rid of the rattles I should be pretty happy with this thing. I mean almost any rock song sounds impressive due to this thing! I'll take a pic of the box tomorrow morning for you to show you that it doesn't take up much space.

Bchester6

A little Polyfill goes a long ways so don't over do it as it can have negative affects as well. I had a 12" Perfect sub in a sealed single cube a long while back and I don't remember it getting crazy low anyways but definitely what I would call a SQ driver. Maybe drop down the x-over point to 70hz? This is also where a 24db slope on your amp would be an effective tool to play around with.

WDPinit

I went pre-fab and the Polyfill was already in there, so I can't imagine it being too much by the looks of it. I actually took the lpf down a bit and it seemed to help. Unfortunately, there isn't a slope setting on this amp. Besides the rattles, I would definitely recommend the Kappa. I got it for $110 shipped, which isn't a bad price at all for what it is. Infinity just came out with their new Kappa subs that go for around $200 and they look AWESOME. Search them up on Infinity.com if you have the time.

cyberquest

i didnt think about the differences between the TL and the RL, i am new to the Acura scene and i have only owned mine a couple of months. my factory system has ten speakers, one in the dash, two tweeter, front and rear door speakers, two rear deck speakers, and a 8" Bose sub. i believe i am the third owner of the car and the first two owners of the car were older people so the stereo probably was set to more talk radio then rap stations....lol. the person i got it from was in the active military and was away from the car as much as he drove it. so the stereo still sounds very good because i dont think its had a lot of abuse. my navigation system does not work so i have no way to adjust the sound and without having those adjustments the stereo is very impressive for a factory system.

and i never gave much faith to 8" subs either until i built a 0.5cf box for a regular cab truck for my son and used a newer company sub called Skar Audio. in a regular cab truck there is not a lot of space for speakers behind the seat and my son is very tall so we didnt want to compromise his leg room so we built a box that would sit on the hump of the trans tunnel between the driver and passenger. because we had such little room to work with and he wanted a ported box i used 4" PVC pipe for the bass port and the entire port extended outside of the box. it came out of the box under the dash and did a 90 degree turn and then had about 18 inches of tube that extended under the dash just above the passengers feet. when we first fired the sub up we just both looked at each other in great amazement because it sounded like a 12" sub.

i dont have a pic of it in the truck but i do have a pic of the box in the hatch of the same car i built the labyrinth box for.


here is the same sub in a box i built for a friends volvo station wagon that wanted a small box that could be removed easy when he needed to use the third row seat.


i am now a huge Skar Audio fan, their MA 8" sub is one bad mofo and can hit low notes like you wouldnt believe. its a dual 2ohm sub so it can run at 1ohm and with the right amp this sub will rattle you to the bone.

WDPinit

Haha, that 8 with the pipe port is bad ass! I have heard good things about Skar and Sundown, their stuff is said to out out loud and clean bass at a decent price. I won't doubt that it gets loud, especially with it being near the driver. My TL doesn't have Bose, but it has ELS. For what it is, it's decent quality. I put different component speakers up front and was surprised that the factory speakers were actually made of halfway decent materials, so I assume the RL is just as good or better. Different sub is a recommended upgrade because the OEM is probably some cardboard pos like in mine. Be sure to check the forums on how to fix the nav, because changing out the head unit in Acuras is not a simple task aside from the RSX and old models!

cyberquest

yes Skar and Sundown are some good stuff, from what i understand the owners of the two companies were partners at one point that went their own direction. Skar seems much more reasonably priced then Sundown and for a person thats always on a budget price is always a factor for me. thats why i always build my own speaker boxes because its much cheaper to buy a sheet of wood, some wood glue and caulking then it is buying pre-made boxes. my buddy has a shop next to my house and he does window tint and stereo stiff and i am able to get my stereo equipment at his cost so thats very helpful. and since i have been building my own boxes i have got pretty good at it and i have done tons of research and anytime he needs a custom fit box he always gives me a call.

here is one i built for a newer style Monte Carlo SS to house two 15's and there was not a lot of space so i had to be creative with the bass ports. he had a pre-made box but it was so wide it would fit between the strut towers and wouldnt go all the way up against the back seat and the subs sat inches away from the trunk so he had no trunk space at all. i had to narrow the box a lot to get it to fit and did not have much room for the ports.


here is another one i built for a hatch back car to house two 8's and they wanted it to angle with the rear glass so the sound would bounce off the rear glass.




i have done a little research on the navi system and mine has the dimly lit black screen so it seems my unit in the trunk needs sent to alpine for repair. being this close to the holidays its not at the top of the list, tax time is probably when it will get fixed

WDPinit

Those are some nice boxes! You shouldn't see building your own boxes as a result of being on a budget, but instead see it as getting the sound you want. I honestly am considering ported as long as the overpowering amp won't blow the sub with it being ported and all... If I decide to go ported maybe in like January or something would you build me a box for SQL if I paid you?
Here's my box btw. Nothing fancy it cost me like $40 online lol

cyberquest

yeah i could build you one but shipping would be expensive. funny thing is i have some friends going to a car meet in Branson MO in 11 days so they could bring the box down to you....lol.

i do happen to have this box sitting in my kitchen just taking up space, i sold the American Bass sub that was in it to the person that is going to Branson. the only thing is he lives 2.5 hours away from me but i am not working right now so i have plenty of free time.


the box is 16" tall, 24" wide, and 18" deep so you would need to measure to make sure it would clear the rear deck. i would take $60 for it but you would have to pick it up from Branson. i can give you the address of the hotel they will be at.

WDPinit

Sorry man, but I am not ready for a box just yet lol I'm on the fence about it. I also live 3 hrs away from Branson anyway haha

cyberquest

thats fine, its just chance i had one already made laying around and had a friend coming to your state in 11 days. he actually would have to pass through st louis on the way there and back.

here is my car when we went down for the car meet in 2009 (black and gold one)

WDPinit

I like that thing lol. It also looks really good for it's age, too! You don't see too many Conquests around anymore ay all(correct me if it's the wrong model lol). Btw I made another adjustment to the LPF and the sub sounds even better hahahaha

cyberquest

good job glad you got it sounding a little better!

your correct its a Chrysler Conquest, i restored that one in 2008, that one was a 87. the car i traded for my Acura was also a Conquest, it was a 84 all original with 59,000 miles on it and i drove it from Ohio to Louisiana to make the trade. if you made that 3hr trip to branson you would see a whole bunch of them......lol.

WDPinit

Well, just when I thought everything was sounding good I'm having amp problems... It keeps going in and out of protect mode and in protect mode little to no bass... Had this happen a few months ago but it would stay in protect for a longer period of time. The cause of that was the fuse would get kinda loose at some spots and it wasn't touching the wires or something always which kept the amp from getting correct power. Guy at the shop put in a new fuse and gave me a bag of fuses that don't get loose but just stop working altogether when they're done for. Any ideas? The sub doesn't sound bad when it plays so idk

cyberquest

i would double check the ground and make sure its getting a good connection. i am not sure where yours is grounded but some people like to use just a self taping screw for the ground and i am guilty of doing it myself once or twice. make sure where ever your grounded you use a wire wheel on a drill or some sandpaper to ensure your getting a good metal on metal ground. i am not sure if you can access the strut from the trunk but thats a good place to get a nice strong ground from since they use larger bolts that you can really tighten down.

the only other thing i can think is the amp is drawing more power then the power wire is able to transfer, from your pic it looks like your using a 8ga power wire which may be a little small since your pushing the amp harder now. most amp kits come with about 16ft of power wire to ensure you can get from the battery to the trunk and resistance increases the longer the wire is.

its all about how much amperage your pulling with your amplifier, to figure this you take your RMS power and multiply it by 2 then divide it by 13.8 volts. your amp is 500rms so times 2 thats 1000, divide that by the 13.8 and your amperage draw is 72.46. the reason you multiply your amps wattage by two is no amp is 100% efficient amps are only about 50% efficient, this means that half the amperage is used to for the audio output and the other half is lost as heat. so with your amp being 500w its actually pulling about 1000w of power from its source.

so your amperage draw is 72.46 and here is a small chart with recommended wire gauge size based on the length of your power wire.


i would double check the ground to make sure its grounding good and if that doesnt solve the problem then i would turn the gain on the amp down a little and see if it will stop kicking into protection mode. if turning the gain down does make it stop then you may need to upgrade to a larger power cable.

cyberquest

on another note you may be able to get away with the 8ga power wire if you install a high current power cell battery. this acts as a second battery for your audio system and will shorten the length of your power wire from the battery to the amp. this stores power so that when your bass hits and the amps peak power draw is reached its pulling its main power from this smaller battery rather then pulling all the power through the full length of wire from your main battery.

this is the one i use, its a Kinetik HC600 and cost around $50 and is rated for 600watts.