Foam sub box lining affecting tuning?

[Outbacksound 1]

I have 4 RF Punch Stage 1's (I know they suck, temporary until I can get more money). I just lined the inside of my box with mattress padding (cheapo, I know). Before I put the foam in the box was tuned to 29 Hz. Did the airspace the foam took up make my box smaller? I built the box with 4 separate chambers, each one being 1.805 cu. ft., which is slightly larger than the recommended 1.79 cu. ft. per sub. So is the box smaller now and have a different tuning? Also, is fast double bass bad for these subs? I have them on a horrible Xplod amp wired at 2 ohms ~600 rms. They sound good, but I know I'll be getting something else asap.

[KU40 173]

Why did you put that in there?

If it's acting like polyfill it will seemingly raise the size of the enclosure about 10%, which would lower the effective tuning frequency 1-2 hz.

Why would double bass be bad for speakers? Isn't that there, um, point of existence?

[Outbacksound 1]

I put it in the box to lower distortion and try to increase bass response.

It sounds better, but I think I lost some output because I have to turn the sub level up in order for it to sound the same as it did before.

Do you think it wasn't neccessary? There's less distortion. I did the big three but my lights still dim badly. Do I need a bigger alternator? My lights dim even when I hit the brakes with no system on or anything else i.e. heated seats, mirrors, heat, a/c, whatever. Do I have a bad ground somewhere?

[jcarter1885 995]

I put it in the box to lower distortion and try to increase bass response.

It sounds better, but I think I lost some output because I have to turn the sub level up in order for it to sound the same as it did before.

Do you think it wasn't neccessary? There's less distortion. I did the big three but my lights still dim badly. Do I need a bigger alternator? My lights dim even when I hit the brakes with no system on or anything else i.e. heated seats, mirrors, heat, a/c, whatever. Do I have a bad ground somewhere?

Read New Topic Guidelines, gives us more information (nobody can tell you what your electrical will need if we dont know what upgrades you have, what stock components you have and what all equipment you are using in the car ). Thankx

[Outbacksound 1]

Sorry. I have a new 85 amp alternator (stock size), a new duralast battery (both failed at the same time).

Stereo equipment:

RF Punch P1S412 (4)

Sony CDX-GT32W (deck)

Sony Xplod XM-1652Z (amp)

Sony Xplod XS-R1643 (speakers)

2&4 gauge wire run throughout

60 amp inline fuse to amp

I know this junk is the worst walmart stuff I could have in my car, which is the worst car I could have (1996 Subaru Legacy Outback), but I have bills and I can only save 50-100 bucks a week towards things. I don't care to hear it's the worst stereo ever because I allready know that. My question is why do my lights dim when I just press the brake or roll up a (power) window? With no stereo on or anything else electrical? Should I get a yellow top deep cycle battery? Or am I gonna have to shell out the $300 for a HO alt.? I replaced the factory grounds from the battery to the frame and from the engine to the chassis with 2 gauge wire, and covered terminal ends with dielectric grease. I had a 1 gauge wire running from my alt. to my battery, but it didn't help at all, and I could only put the screw on the alt. post about 3/4 to one turn, so I removed that. At this point, it's an electrical problem with grounds somewhere, or my system is killing my battery and alt. again. I know caps are only band-aids to the system but would one help? Or are they a complete waste of money?

[bigrank916 72]

If there is no stereo on or anyhting else and it does that, then it sounds like you have a power prob in the vehicle. Maybe your alt is getting bad?

[jcarter1885 995]

Sorry. I have a new 85 amp alternator (stock size), a new duralast battery (both failed at the same time).

Stereo equipment:

RF Punch P1S412 (4)

Sony CDX-GT32W (deck)

Sony Xplod XM-1652Z (amp)

Sony Xplod XS-R1643 (speakers)

2&4 gauge wire run throughout

60 amp inline fuse to amp

I know this junk is the worst walmart stuff I could have in my car, which is the worst car I could have (1996 Subaru Legacy Outback), but I have bills and I can only save 50-100 bucks a week towards things. I don't care to hear it's the worst stereo ever because I allready know that. My question is why do my lights dim when I just press the brake or roll up a (power) window? With no stereo on or anything else electrical? Should I get a yellow top deep cycle battery? Or am I gonna have to shell out the $300 for a HO alt.? I replaced the factory grounds from the battery to the frame and from the engine to the chassis with 2 gauge wire, and covered terminal ends with dielectric grease. I had a 1 gauge wire running from my alt. to my battery, but it didn't help at all, and I could only put the screw on the alt. post about 3/4 to one turn, so I removed that. At this point, it's an electrical problem with grounds somewhere, or my system is killing my battery and alt. again. I know caps are only band-aids to the system but would one help? Or are they a complete waste of money?

Since your alternator is so low, I would get a bigger battery up front or get a HO alternator because your stock alternator is barely covering the basics with the car on and no accessories playing. I would also check to make sure that your grounded to good locations and all the paint is sanded off (if you get a DMM and find a spot with 0 resistance then your good).

[KU40 173]

Go to autozone or somewhere and have your alternator and battery load tested. If your lights dim just by pushing on the brake pedal or rolling up a window one of those almost has to be going bad. A capacitor will do nothing for you.

[Outbacksound 1]

Go to autozone or somewhere and have your alternator and battery load tested. If your lights dim just by pushing on the brake pedal or rolling up a window one of those almost has to be going bad. A capacitor will do nothing for you.

I used a multimeter a few days ago. The battey had 12.75 volts with the car off and 14.4 volts with the car running. I then had someone turn on the lights and the voltage went down to 14, and with the fog lights on it whent down to 13.8. With the brake pedal pressed, it went down to 13.5. However, after turning off the lights and releasing the brake, it stayed at ~13.8v. I just replaced the alt. and the battery about a month ago. The car was overheating every couple days, and I would pull over and put water in the radiator because coolant was flowing out of the resoivoir pressure hole. One night it started to rise when I was a 1/4 mile from my house, so I thought I could make it home. The second I pulled into my street, the car stopped. Engine kept running, but RPM went to 0, all my dash lights came on, and boiling coolant smoke poured out from under the hood. An hour later I turned it over, and it started up fine, but the battery and emergency brake light stayed lit. After a few days, my car was turning over slowly, so I got the battery tested at autozone, and they said it was no good. With the battery replaced, my battery light on my dash, as well as the e-brake light, were both still on. Tested the load at autozone and the alt. wasn't doing anything. Had about 12.5v with the car running. So both were replaced the same day. Could they, or at least the alt. be going allready?

[bigrank916 72]

What does that mean? The alt was doing nothing.

[Outbacksound 1]

What does that mean? The alt was doing nothing.

It means the alternator was dead. My car was basically an R/C car, running solely on the battery. Once the car is started, the car should be using the electricity produced by the alternator to run everything; spark plugs, lights, anything electrical. While the car was running it was producing as much voltage as when it should be off. It should have been 14-14.4 volts when running, so that determined the alt. was dead.

[KU40 173]

Try turning on your AC. If the voltage dips down into the 12s and stays there (at or below the battery's resting voltage), you have a bad alternator. You may have just gotten a weak one when you replaced it, or if your car still has the overheating issues that may have hurt it. Heat is the worst enemy of anything electrical, even just the ambient heat from the engine.

[///M5 2,833]

I'd remove the mattress padding as it isn't helping with ANY of your goals. I'd also set the gains on that amp ONLY with an oscilloscope as I am sure you a driving it well into clipping.

[Outbacksound 1]

I was going to take out the padding, but I wanted to achieve better sound quality from these drivers, and i think they sound better. They sound less muddy and a little more accurate. I don't turn them up all the way, because they're loud enough at mid-volume. The only H.O. alt. I can find is the Fitzall from PowerBastards.com. Is this a reputable site? I've checked all other online parts stores and they don't have them for a subaru. I also don't know if I want to put another $300 towards an alternator for this car. I just spent 150 on this new one, and I'm not going to have this car forever. I have the gain on the amp a lIttle less than 3/4. It puts out 390 watts per channel at 2 ohms (I think). So since I have two sets of drivers each wired in parallel, each sub should be receiving less than 150 watts, which would be within their RMS rating. Unless my amp is a little strong, they should be ok, right? By the way, I don't have, or know where to get an oscilloscope, nor do I know how to use one. Ive heard it shows electrical fluctuation in a wave pattern but this is basically useless info to me.

And thanks to everyone for posting

[///M5 2,833]

Unless there is something seriously funny with your box, the "less muddy and more accurate" is not related to the stuffing. Placebo effect only.

I am not so sure that amp will do power, so I'd set the gains real conservative if you don't have a scope.

[KU40 173]

Also, if I'm reading what you wrote correctly, you are incorrectly thinking you are only getting about 300 watts per channel because you only have the gain 3/4 up. The gain is not a volume knob, it doesn't work like the volume setting on your head unit. You very well could be getting full power from the amp at that setting, and could even be passed that and into clipping. It all depends on the signal voltage from the head unit to the amp. The gain is only to match the amplifier to that input voltage.

[Outbacksound 1]

I read that standing waves inside of a box will produce a sound that comes through the cone with the sound waves coming off of the front of the cone, which causes distortion. An open celled foam will absorb certain frequencies and produce better sound. But I fell as though I did lose a lot of sound. I'm going to think about removing the foam, because it's a hell of a process to get my box out of my car and take the subs out, etc. So you think I should turn the gain on my amp down to prevent overdriving and clipping?

[Outbacksound 1]

You might find this interesting- I'm not saying your wrong, but this is a different view on gain level

http://www.teamrocs.com/technical/pages/gains.htm

[Impious 1,476]

I read that standing waves inside of a box will produce a sound that comes through the cone with the sound waves coming off of the front of the cone, which causes distortion. An open celled foam will absorb certain frequencies and produce better sound.

Standing waves are not going to occur within the enclosure due to the small size of the enclosure compared to the wavelength for subbass, unless you have an enclosure the size of a room or are running your subwoofer up to several hundred hz.

[Impious 1,476]

You might find this interesting- I'm not saying your wrong, but this is a different view on gain level

http://www.teamrocs....pages/gains.htm

Don't pay too much attention to that article, as there's not much worthwhile information contained in it. He's merely contributing to what he's apparently attempting to disspell, as outlined in the opening sentence....All that article proves is he really doesn't understand the function or use of a gain control.

[Outbacksound 1]

Don't pay too much attention to that article, as there's not much worthwhile information contained in it. He's merely contributing to what he's apparently attempting to disspell, as outlined in the opening sentence....All that article proves is he really doesn't understand the function or use of a gain control.

Yeah, I read a lot more after I posted that link and I have seen the error of my ways.

On a side note, how many layers of damplifier would make my roof cut out it's obnoxious nonsense?

[ChristianMcKay 1]

I think you're going to have to be a bit more specific when you say, "it's obnoxious nonsense."

[ChristianMcKay 1]

I have 4 RF Punch Stage 1's (I know they suck, temporary until I can get more money). I just lined the inside of my box with mattress padding (cheapo, I know). Before I put the foam in the box was tuned to 29 Hz. Did the airspace the foam took up make my box smaller? I built the box with 4 separate chambers, each one being 1.805 cu. ft., which is slightly larger than the recommended 1.79 cu. ft. per sub. So is the box smaller now and have a different tuning? Also, is fast double bass bad for these subs? I have them on a horrible Xplod amp wired at 2 ohms ~600 rms. They sound good, but I know I'll be getting something else asap.

Also, I have two of these subs, and putting it in a ported box is a bad idea for fast double bass. I think you would probably rather go sealed. I have mine sealed and they handle fast double bass drums perfectly.

[Outbacksound 1]

It vibrates so bad that it produces a note you'll hear a 1/4 mile away. My rear drivers side door vibrates really bad, and the hatch does too, but I'm going to try New weatherstripping for the door and the hatch because it's not the sheet metal that's making the noise. They travel in and out visibly.

I mainly listen to heavy bass music, bass testers, rap, but I like to listen to hard music too, just nowhere near as much. Sealed boxes sound deeper I hear, but not as loud. I honestly don't care if they aren't as loud if they play lower notes louder. But tuning so low I finally got the sound I was looking for, as well as improving SQ.

They're in a box facing up. Should I make a box, sealed w/ 2 facing the front, and 2 facing the rear, or keep with the face up design?

[///M5 2,833]

It vibrates so bad that it produces a note you'll hear a 1/4 mile away. My rear drivers side door vibrates really bad, and the hatch does too, but I'm going to try New weatherstripping for the door and the hatch because it's not the sheet metal that's making the noise. They travel in and out visibly.

I mainly listen to heavy bass music, bass testers, rap, but I like to listen to hard music too, just nowhere near as much. Sealed boxes sound deeper I hear, but not as loud. I honestly don't care if they aren't as loud if they play lower notes louder. But tuning so low I finally got the sound I was looking for, as well as improving SQ.

They're in a box facing up. Should I make a box, sealed w/ 2 facing the front, and 2 facing the rear, or keep with the face up design?

And you were worried about your subs sounding clean in your box??

There is a link in my sig to SDS. Applying some dampener to the areas that flex the most is definitely the first starting point. "How much" depends a lot of "vibrates so badly" but starting by covering 25% of the exposed metal would definitely get you moving in the right direction.