Questions About My New Subs (w/ Pics)

[07mazda3s]

So Thursday I ordered my 2 15's. I got the Power Acoustik PW2-15M's. Subs At least for a while, I am gonna be pushing them with 250watts rms each.

Here's my problem, at least with the box I have now, it is way louder with the sub/port facing the back of the car. On songs with heavy bass, I worry about the trunk and the window already, and that is with 1 12 on 250watts rms.

I'm worried about blowing the seal on the back window or blowing my trunk latch....sooooo I was just going to build a box with the subs facing into the cab, however, the new box will be sealed instead of ported, but I'm just wondering how much bass I will be sacrificing to save my car....The box for the 15's will only have about 5 inches of space on either side of it going back to the trunk but I am not going to seal it off. So, what does everyone think?

Thanks everyone!

Edited November 16, 2007 by 07mazda3s

[07mazda3s]

Is it a really bad idea to face the box forwards without sealing the trunk?

[dwright27]

that box you have now must be incredibly effecient.

that is some nice flew for that little bit of wattage.

if your window breaks, just get another i really dont see it breaking though. it takes alot of pressure to break glass.

Edited November 12, 2007 by dwright27

[07mazda3s]

that box you have now must be incredibly effecient.

that is some nice flew for that little bit of wattage.

if your window breaks, just get another i really dont see it breaking though. it takes alot of pressure to break glass.

I'm worried about blowing the seal not the window...I just want to know, am I losing a whole lot of bass by firing forwards instead of backwards?

[white_boi_audio]

I'm worried about blowing the seal not the window...I just want to know, am I losing a whole lot of bass by firing forwards instead of backwards?

Well I have heard that if you have a box in the trunk and you face it into the cabin or seal it off if you have fold down seats. The only thing with the subs firing into the cabin there is a bigger area that the sound wave has to create the loud deep bass. If you fire the subs to the back of the trunk the subs tend to create the sound wave and then bounce off the back of the trunk and go forward toward the front of the car. If you just make a box and turn it into the cabin and don't seal it off you will lose loudness etc. Maybe somebody that has had the two different setups could tell you. I know that when I turned my box around I lost output.

[07mazda3s]

I know that when I turned my box around I lost output.

I did too, but my box for 1 12 has like 10 inches on either side allowing air back into the trunk and it is ported...With the 15's there will be like 4 inches on each side of the box and its sealed...I feel like the air flow would be restricted if the subs were faced backwards because there is so little space on the sides for the air to get around into the cabin...I agree with you tho whiteboiaudio, when I face my current setup forward, I lose a considerable amount of output, but my rattling is completely eliminated.

[dwright27]

I did too, but my box for 1 12 has like 10 inches on either side allowing air back into the trunk and it is ported...With the 15's there will be like 4 inches on each side of the box and its sealed...I feel like the air flow would be restricted if the subs were faced backwards because there is so little space on the sides for the air to get around into the cabin...I agree with you tho whiteboiaudio, when I face my current setup forward, I lose a considerable amount of output, but my rattling is completely eliminated.

you lose output when you face it forward because the wave has nothing to "load" off of. as opposed to it loading off the trunk of the car when its faced rearward.

[07mazda3s]

I have a question...If I wire my 15's to a 4 ohm load, they will get a rated 500wrms bridged between the two...If I wire each of them to 2 ohms on a channel of the amp, it can handle a 2 ohm load but is rated 200wrms x 2 @ 4ohms...So will I be better with each sub on a channel @ 2 ohms or the two subs wired together @ 4 ohms?

[Derrick824]

With the 15's there will be like 4 inches on each side of the box and its sealed...I feel like the air flow would be restricted if the subs were faced backwards because there is so little space on the sides for the air to get around into the cabin...

In my experience, larger boxes do better facing forward but they must be pushed all the way to the rear of the vehicle. Moving them just 12" or so forward has resulted in a 3db loss. I've also seen good results facing subs up in a trunk but the rattling was worse then facing the rear.

[07mazda3s]

In my experience, larger boxes do better facing forward but they must be pushed all the way to the rear of the vehicle. Moving them just 12" or so forward has resulted in a 3db loss. I've also seen good results facing subs up in a trunk but the rattling was worse then facing the rear.

Yeah, with sound deadener my rattling is almost unbearable with one 12 sub and port facing back. I'll def fire the new subs forward and try what you said about pushing the box back...

Thanks man I will try that out

Can somebody please help me out with my wiring question...

The amp is rated 200wrms x 2 @ 4ohms but can handle a 2 ohm load on each channel...It's also rated 500wrms x 1 @ 4 ohms.

Will I be better off with a sub on each channel @ 2 ohms or bridged @ 4 ohms....or is the amp internally regulating those to the same exact thing?