Bayuk89 Posted June 27, 2016 Report Share Posted June 27, 2016 I built a box for my two SA-18's its 10.5 cubes after displacements tuned to 32hz with 127 inches of port powered off a 1500 watt rockville M4 amp..... Its loud dont get me wrong, but i feel like i wanna buy a better quality 2-2.5k amp and build a new box. On this woofer box app i downloaded off the google play store it shows a graph of the bandwidth when i plug in the T/S parameters, box size and tuning and cabin frequency (my dodge ram 1500 is about 40-45 hz) and the graph shows 145.2 dB @ 38 Hz @ 938 watts. Im tuned to 32hz and graph shows my bandwidth to play 30-60 hz fairly flat across.... when increase the box size from 10.5 to 12 cubes and change port from 127 inches to 140 inches the bandwidth didnt change very much but my wattage went from 38hz @ 938 to 34hz @ 1089 watts ( on the same 1500 watt amp.... i tried 10 cubes net ( smaller box to help control cone movement with extra power now ) with 130 nches of port ( keep the velocity up ) tuned to 32hz on 2500 watts and it said i peaked at like 37 hz but only on 788 watts ???? Box too small for extra power choking it out ?. My goal is to play 25-50 hz i prolly wont compete with these subs, i just want my lows to be loud and have authority. Though about building 12 cubes net tuned to 29 hz with 140 inches of port on 2500 watts Link to comment Share on other sites More sharing options...
Broke_Audio_Addict Posted June 27, 2016 Report Share Posted June 27, 2016 Get a new amp, then see if you want a new enclosure or not, But I doubt you will, that amp is holding you back. That being said a lot of people's definition of "music" is a clipped 30 hz sine wave with some 80 IQ knuckle head grunting about committing crimes and his genitals. Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 Basically i wanna build a ground pounder...... i know the sa-18's dont have a whole lot of suspension travel (compaired to others) so i dont expect it to move as much air as a zv4 lol but i know the sa-18 can get down for what it is. I just need some better direction from more experienced guys on how to accomplish my goal. Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 Get a new amp, then see if you want a new enclosure or not, But I doubt you will, that amp is holding you back. No doubt there lol honestly i like this little bastard but i need more powaaa. Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 I could keep the box as is @ 10.5 and add on the port externally to tune it to 29hz.... port is 6.25" wide by 20.5" tall for two 18's im not sure if 2500 watts at them with 127 inches of port is too small and choke them out... prolly need more port area with more power ? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted June 27, 2016 Report Share Posted June 27, 2016 I could keep the box as is @ 10.5 and add on the port externally to tune it to 29hz.... port is 6.25" wide by 20.5" tall for two 18's im not sure if 2500 watts at them with 127 inches of port is too small and choke them out... prolly need more port area with more power ? Generally speaking, more power requires more port area, you want to keep port velocities low for best efficincy. With ported boxes, more excursion capability doesn't always mean more output. This is because you peak output often comes at tuning, where excursion is low. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 ^^^^^ i hear you man if my current box is built for 1500 watts, throwing 2.5k at it i was thinking i need more port area. Im finding its all trial and error and i understand i prolly wont get the exact answer i want and i just have to play with it.... so is 127 inches of port too small for 2500 watts ? Prolly need 140-150 inches of port with the extra wattage ? Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 im tuned at 32 i can play down to 26 safely but my bandwidth plays 30-60 hz pretty flat (according to my SPL graph on the bass box app) anything before or after is on the down slope.... figured i retune from 32 to 29 i can move my bandwidth more down low. Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted June 27, 2016 Report Share Posted June 27, 2016 im tuned at 32 i can play down to 26 safely but my bandwidth plays 30-60 hz pretty flat (according to my SPL graph on the bass box app) anything before or after is on the down slope.... figured i retune from 32 to 29 i can move my bandwidth more down low. Yeah you should be able to play a little lower, but a 3 Hz change in tuning isn't going to make a big difference, it may not even be noticeable. I checked your port velocities in simulation. At 127 sq in, you have quite a bit of head room before port velocity will become and issue. 2500 watts should be no problem at all. I also agree with Broke and think your amp may be holding your back. The first thing I would do is make sure you are getting all the power out of your amp that you can. I don't remember how you set your gains, but there may be some more performance you could get there. The next step after that would be to go to a larger amp. As far as you box goes, you could play around with lowering tuning by extending the port externally. Your port area should be sufficient up to as much power as those subs will take. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
Bayuk89 Posted June 27, 2016 Author Report Share Posted June 27, 2016 ^^^^ my amp was tuned with a DD-1 with -10 dB when i had my no name battery under the hood and my power and grounds were 2ga welding cable. I upgraded my power and grounds to 1/0 welding cable, added a deka 1131mf in the truck tool box and replaced the no name starting battery with a deka group 65 and replaced my cheap walmart RCA cable with stinger 6000 series. Since then the subs played alot louder and i could smell coil within a few minutes at full tilt, so i took a paintmarker and marked the gain setting and turned it down about 1/16 th of a turn. Certain songs i get stinky coil but nothing like how it used to be, i need to retune the amp with -5 dB now but i lost the guys number who had a DD-1 so i have to buy my own. I agree with broke audio and you, No doubt the rockville is holding me back. Last time i clamped it when i had my 15's i got a lil over 900 watts (according to the math) prolly still getting 900-1000 watts with this new sub stage but i also know box design can effect amps usable output. Link to comment Share on other sites More sharing options...
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