Drumgar69

ok, I put the box into the HHR. I loaded it into the hatch corner. I figure .61 cubic ft tuned to 41. I was worried about high tuning but it sounds good now. It played the skrillex just fine with authority. I got the "wow" from my friend. Dont know why Sundown put a box build together for single SA 8 at .97 @ 28hz. I guess everything should be double checked before building. Thanks everyone for you help.

Hey strange duck I see you got drag racing video's up on you youtube page. Im going to NHRA RT66 races today. I love Nitro and tire smoke.

the 2x4 are 9.75" and I put 11 of them in. Also I took out the 3rd 8" short leg of divider that created the port. So I have shortened the port which adds volume to the box. I left that divider inside the box which I calculated @.03 cubic feet of space. So 11 boards at 3.5" x 1.5" x 9.75" plus the 8.5" x.75"x 9.75" port baffle now glued to the inside.

Well it is definetly to big of box. Playing with torres I input the parameters of this box and the net volume was right at 1 cubic foot and tuning at 28hz. This would have been a good box for a SA 10. I wonder if it is just a mistake on Sundown website because it does not fall into their own recommended box sizes. It could be my math is wrong as I am new to Torres. Any way I decided at this point I would frankenstein this box for testing, or put into the burn pile. I took out the 8" third leg of port and reduced internal volume by adding 2x4 into the inside to take up room. After slopping it to gether with glue and trim nails I put it back on the amp. The smaller internal space is definetly controlling the excursion of the sub and it is handling all the power of the crown amp now no problem. I estimate a net volume of .67 cubic feet tuned to 38hz. Now it just doesnt hit low at as good as it used to so probably something is off with this......grrrr frustrating making a box and it not sounding good. Here is a pic of the added mass to inside of box.

I think thats were my unrealistic expectations comes in. What sounds good to someone is subjective, but to me the sub does not sound as punchy as I would like. I have proved that this takes well over rated power and should be fine with 750-900 watts going to it, its just its not very loud in my garage in the open, or not as much as I thought it would be in the back of the HHR. This is a learning process for me and I appreciate the input.

ok, I think my problem may be in the box design. I have been using test sine waves from files downloaded from this site. Using the crown amp, which has clipping protection and will bring power down when clipping. Since I dont have a device to measure db I am just using my ears to hear how loud and clean this woofer plays. I tested using 40,50,60, 70 hz sine waves, cooling the coil down to 97 degrees between pulls. To my ears the box performs better @ 40hz than 60 or 70. I am not sure if its is mechanical limitation noise or distortion or what, it makes a loud BRRRRAAACCCCKKKK noise at the high end of 50hz and 60hz. The sub is 2 ohm voice coils wired in series. My friend who I built this for listens to mostly rock and the occasional skrillex type stuff just to show off system. I think a box re-design my be need to get better spl in the 50 to 80hz range. 40hz=72v max=1296W 50hz=63v hit noise=992w 60hz=74v hit noise=1369 70hz=65v=1225w

This is bugging me pretty bad. I decided to take the box out of friends car for testing here in my garage. I lent him a single BA 15" in sealed box to use while I test this this sub out. I have a Crown CDI 1000 bridged which is capable of 1000 watts. The Crown should be comperable in output to RF 750 according to the SMD amp dyno testing. I am running sine waves of different frequencies seeing how much it can take. Im letting it cool down between runs. I really wish I had a program and mic to check the spl output. Any tips you guys can throw my way would help.

pulled the sketchup model from Sundown site. There is actually no information about what the internal volume or tuned frequency is. I guess I just assumed it was within the recommended range since it came from their website. I started adding up dimensions to calculate the internal volume. I am not sure wheather to add the slot port volume to the volume of box or not. If so This box is well over 1 cubic foot. Anyone from Sundown on this formum regarding their recomended box dimensions?

I dont have the dimensions on me right now.On sundown website they have a sketchup and cut sheet for the recommended box. I followed that hoping to take the guess work out of boxbuilding. Btw the box i built out of 3/4 furniture ply from an olf entertainment center and glued and screwed pretty tight. Ill get the dimensions when i get home.

Here is some info on system I put in for a friend on his 07 HHR. The Box I built is the design off of the Sundown site, which is the recomened ported box for a single 8. Amp is Fosgate Prime 750D with subsonic filter set at 30ish. We are using stock HHR head unit, which is unpowerd to be used with factory amp. Ive had to turn the gains down pretty low on the RF prime amp, and only push the stock deck to 80%. I do not have an O-scope so I am not for sure that there is no clipping. I will say this is impressive for an 8" sub. I had expected more after watching youtube videos and surfing forums talking about how much these subs can take. The little sub seems to come alive when you push it pretty hard, but we have been hearing that awful noise when it bottoms out. I assume I need to make the box smaller to help control the sub from hitting mechanical limit. Do you think I should make a smaller box, or just realize I had too high of expectations for a single 8". Here are some pics of the box. Regards, Wes