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Everything posted by airofu

  1. Thanks it could be something like that will have a play around a bit more
  2. I know I designed it as I entered the figures in myself What I'm trying to work out now is why two different programs are giving me different net volumes when both dimensions are entered the same like in the screenshots. The difference I am seeing is that they are calculating the total port volume differently for some reason which I can't work out.
  3. I really like the subboxpro design program, but I am still not sure why Torres is giving me different net volume unless I did a type somewhere regardless of final volume and tuning? I just don't want to go ahead with anything if subboxpro is somehow wrong vs Torres?
  4. Thanks for the feedback, the bit I'm still stuck on is that subboxpro gives me 2.5 net after port displacement which is what I was aiming for originally, but Torres/yourself is saying the 2.68 net which is pushing it like you say. Is subboxpro wrong?
  5. Hoping to check the subboxpro design I've got here looks ok before I start it? eg. net volume and port length are calculated correctly thanks
  6. I'm building up a box for my Skar VXF 12" (0.14ft displacement, pushing around 1700rms currently) looking at 2.5ft net tuned to 28hz and 30sq port. I've designed the box dimensions in subboxpro external height 17.56" x Width 17" x Depth 25.44" to fit in the back and happy with it, but then I checked in Torres and I think I copied it all the same, but I noticed Torres gives me about 0.18 less port displacement so more net volume 2.68 - not sure how Torres is designing the port in terms of location and bends in the box. But basically is the subboxpro design accurate and looks ok?
  7. Just wanting to add more in, if I use an oscilloscope to adjust my amp gain, am I right to assume that if the voltage calculated is higher then what I thought I would get, I am simply getting more power from my amp before clipping which is good?
  8. Thanks, I've only got 800rms on it right now and can tell it wants way more! My alternator is 180a - I was playing it safe with a 1500rms amp, or could I push a higher wattage amp like 2.5k? Big 3 not an option...
  9. Still finalizing amp but looking at Skar RP-1500 - 1500rms at 1ohm, don't think I will be upgrading this. I do like lows and a flatter response...but I'm just wondering how noticeable it will be going from a 2ft box which seems ok to only 2.5ft in terms of output/lows?
  10. I've currently got a new Skar VXF 12" in a 2ft box tuned to 28hz, would there be a noticeable gain changing to a larger 2.5ft (or bigger) 28hz box? I understand it should hit a bit lower and louder which I am after, but will it be noticeable from a 2ft box which seems to be average for a 12"?
  11. Looking at the Skar RP-1500 myself, for the money and dyno ratings (slightly underrated) looks the best value.
  12. Installed an older monoblock amp, powers up ok, but noticed it going into protection mode each time the bass hits (even with sub disconnected, worse when it is and seems to draw heaps of power as the car lights flick also, but no output to the sub), I'm guessing something is overloading on the amp even with gains down, can it be repaired easily? Swapped over to a working monoblock on the same cabling and works fine.
  13. Just wanted to clarify that setting my SSF and LPF with DMM on my amp is to multiply or divide by .707? I've read both and different for each.... I thought it was multiply to set a lower voltage for both eg: - SSF at 25hz - set volume get voltage multiply by .707 - play 25hz test tone and set SSF until i hit this lower voltage? - LPF at 80hz- set volume get voltage multiply by .707 - play 80hz test tone and set LPF until i hit this lower voltage?
  14. Thanks for the replies looking at a Skar SDR which is potentially a little underrated. If I am playing music as a daily, it sounds like you can also go a bit above RMS as it's not always going to peak the wattage based on the music/impedance rise?
  15. Just using a multi meter and oscilloscope (same as a DD1?) to work out estimated distortion free output from the amp, with a hypothetical 600rms sub and 1500rms amp at 1ohm. Do I set the amp hard at 600rms to match the sub or give it a bit more due to playing music not tones/impedance rise? 800rms? more?
  16. If I have a subwoofer that is 600rms rated 1200w peak - but an amp that can do 1500rms, what should I set my max output too on the amp for this sub? I get having a bigger amp gives me more headroom and less likely to distort as it won't max out as would be this case, but do I still set the amp as max output for the rated 600rms? I read about 50% more....but is that headroom vs actual power to the sub?
  17. Thanks all, seems like I am on the right track. Will look at 45 or rounding all the port edges (assuming it might drop my port length by an inch or two)
  18. Thanks, I think I doubled up a wall internally like you said equals about 1.42cft for the port now...which brings it down to about 19" wide like you say which is good to know! Is the tuning length as easy as measuring the port from the middle? or do the 2 turns and inside port somehow change the way I should be l looking at it?
  19. I've run some figures, hopefully I am on track. 28hz port at 40 square inches is 2.5" by 16" and 47.24" long with 0.75 MDF would take up 1.91cft gross - I added this to a box design for 2.5cft internal volume (plus 0.15 sub displacement) to get a box that seems to just fit with total external dimensions of 21" wide 17.5" high and 26.74" deep. Will making the slot port a U inside, change the length/tune that I am not thinking off?
  20. I'm hoping I can get some ideas and help on a box I want to build for a single American Bass XR 12" - looking at pushing about 1500rms and wanting to tune at 28hz as I want it to hit nice and low. Sounds like pushing the box to 2.5cubes is the way to go (unless smaller is recommended based on tune and power?), sub displacement at 0.15cft, 0.75inch MDF, my maximum outside dimensions are 21" wide (would want to reduce this as much as possible) 17.5" height, and 26" deep which can stay if it works. I am mainly having trouble keeping to 40 squared inches of port area which seems to be the minimum based on the box and power? The box design software won't give me a U port (colored red, will this work?) and is where I am stuck as the port is too long for just an L:
  21. Thanks, keep us updated on your box and how the XRs sound. Seems like a bigger box seems to help dig the lows in general from what I've read....
  22. Make sure the remote bass remote is up, turn LPF higher and subsonic lower to test it's not cutting the frequencies out somewhere in the middle, I've also made the mistake of setting my gains with my subsonic filer and LPF on (and HU settings not flat) which messes with the DMM readings ....though it sounds like you have covered all these things....amp issue? Though I imagine if it's putting out the right voltage it should be ok.... On break-in, I noticed my sub seemed to hit a bit lower after a few weeks of usage, but as mentioned not a night and day difference.
  23. I'm looking at making a box for a single American Bass XR 12, looking at giving it about 1500rms and wanting to tune low 28hz for most output down low and relatively flat response. How big should I go, consensus seems to be about 2.5cft max? Lower 2-2.25cft? Also based on all this would 40 square inches of port area be sufficient?
  24. Just wondering what's the best position in the trunk if I am designing a new sub box (around 2.5cft - 28hz) for my SUV. I've gathered generally rear facing will be best (if not which direction would be recommended for sub and port?) but sort of have 3 designs, one with the box right back to the rear seat, about midway and a lower but longer box getting the sub much closer to the rear. I am guessing the longer box closest to the rear trunk will load the loudest? Other ideas?
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