LZTYBRN Posted January 18, 2011 Report Share Posted January 18, 2011 I just installed my subs and they sound great, and everything is good, except for these two options. The manual for the amp had a guide for setting the input gain, but it made little sense to me, and it didn't explain the reasoning behind the steps. So, I'm not really sure if I did it right. If I remember correctly, it's set about one third of the way up (120mV-6V.) As for the subsonic filter, the manual has no guide at all, so I'm quite lost. It goes from 20Hz to 50Hz, and my box is tuned to 42Hz, if that helps. So, anyone know how I should set these options? Quote Link to comment Share on other sites More sharing options...
osamio Posted January 18, 2011 Report Share Posted January 18, 2011 (edited) I just installed my subs and they sound great, and everything is good, except for these two options. The manual for the amp had a guide for setting the input gain, but it made little sense to me, and it didn't explain the reasoning behind the steps. So, I'm not really sure if I did it right. If I remember correctly, it's set about one third of the way up (120mV-6V.) As for the subsonic filter, the manual has no guide at all, so I'm quite lost. It goes from 20Hz to 50Hz, and my box is tuned to 42Hz, if that helps. So, anyone know how I should set these options? The input gain should be set to match the output of your head unit (the RCA cable voltage) if you have an aftermarket head unit, it should be 2-4 volts. Consult the manual, then match the gain on the amp accordingly. The Subsonic filter should be set to match the tune of your box...In a ported enclosure, if the sub plays a frequency LOWER than the tune of the box, it loses it's air cushion, and turns into a free-air enviroment. It will cause the sub to over extend and bottom out, and eventually blow the woofer. The subsonic filter is designed to cut off any frequency BELOW where it is set, so set it as closely as u can, if not just above, the tune of your box. **EDIT If your amp is capable of exceeding the rating of your subs, you may need to adjust the gain accordingly, in order to prevent blowing your subwoofers when the volume is up to your maximum listening level, if you need more information on that, then i'd need to know what amp and subs you have. Edited January 18, 2011 by osamio Quote 2009 Cobalt LT Pioneer Headunit 2x Pioneer 6 1/2 (stock amp) 2x Pioneer 1" tweeters (stock amp) 2x Pioneer 6x9 (stock amp 4x Pioneer 6 1/2 Pioneer GM-6400F Soundstream DTR 1700 R.I.P 2x Champion series PRO 12" subs 0 AWG Big 3, Stinger SP1700 battery To come: New or repaired DTR!! Link to comment Share on other sites More sharing options...
Rebel4055 Posted January 18, 2011 Report Share Posted January 18, 2011 Subsonic is usally set 2-3hz below tuning in a ported box, in sealed I forgot. To set your gains by ear turn your HU to your listening volume and then turn the gain up till you start hearing distortion then turn it a bit down from that point. Or if you have a DMM follow this guide. The correct way to set your gains is using a oscope. Quote Rest In Peace mother. January 22, 1955 - February 14, 2013 http://www.stevemeadedesigns.com/board/user/35351-megrch/ Link to comment Share on other sites More sharing options...
LZTYBRN Posted January 18, 2011 Author Report Share Posted January 18, 2011 Thanks guys, seems pretty simple. And I don't see anything indicating the rating of the subs, so my subs: Boss P126DVC (x2) and my amp: Power Acoustik CPT1-4000D. Also, for my head unit, it says the Preamp voltage is 2V. That's the number I match it to right? And out of curiosity, what are the consequences of not setting the gain correctly? Quote Link to comment Share on other sites More sharing options...
osamio Posted January 18, 2011 Report Share Posted January 18, 2011 Thanks guys, seems pretty simple. And I don't see anything indicating the rating of the subs, so my subs: Boss P126DVC (x2) and my amp: Power Acoustik CPT1-4000D. Also, for my head unit, it says the Preamp voltage is 2V. That's the number I match it to right? And out of curiosity, what are the consequences of not setting the gain correctly? Well, i'd be careful, your subs are rated at 1200 Watts RMS, depending on how u wire it, your amp can put out 4000 Watts, that's 2000 to each sub... IF it puts out that much in a real world scenario, for an extended period of time, it will blow your subwoofers. it will over heat the voice coil, and cause the sub to freeze up. Or cause the cone to over extend and bottom out, which can tear the surround. I'd follow the guide in that other post to set your gain so the amp doesn't put out anymore than 2400 watts. Quote 2009 Cobalt LT Pioneer Headunit 2x Pioneer 6 1/2 (stock amp) 2x Pioneer 1" tweeters (stock amp) 2x Pioneer 6x9 (stock amp 4x Pioneer 6 1/2 Pioneer GM-6400F Soundstream DTR 1700 R.I.P 2x Champion series PRO 12" subs 0 AWG Big 3, Stinger SP1700 battery To come: New or repaired DTR!! Link to comment Share on other sites More sharing options...
Rebel4055 Posted January 18, 2011 Report Share Posted January 18, 2011 That amp probably doesn't even do more than 1200... Quote Rest In Peace mother. January 22, 1955 - February 14, 2013 http://www.stevemeadedesigns.com/board/user/35351-megrch/ Link to comment Share on other sites More sharing options...
osamio Posted January 18, 2011 Report Share Posted January 18, 2011 That amp probably doesn't even do more than 1200... But seriously... maybe he should meter it real time, see what it is putting out, and adjust real time... AND in addition i'd be surprised if those subs can handle 1200.... REALLY surprised... Quote 2009 Cobalt LT Pioneer Headunit 2x Pioneer 6 1/2 (stock amp) 2x Pioneer 1" tweeters (stock amp) 2x Pioneer 6x9 (stock amp 4x Pioneer 6 1/2 Pioneer GM-6400F Soundstream DTR 1700 R.I.P 2x Champion series PRO 12" subs 0 AWG Big 3, Stinger SP1700 battery To come: New or repaired DTR!! Link to comment Share on other sites More sharing options...
LZTYBRN Posted January 18, 2011 Author Report Share Posted January 18, 2011 Well I have it wired down to 4 ohms, so each sub is only getting 600W, because I was told these subs could only handle about that much. Should I be good then? (I don't have the CD or a multimeter :/) Quote Link to comment Share on other sites More sharing options...
osamio Posted January 18, 2011 Report Share Posted January 18, 2011 Well I have it wired down to 4 ohms, so each sub is only getting 600W, because I was told these subs could only handle about that much. Should I be good then? (I don't have the CD or a multimeter :/) Ya that should be fine, Set the gain to match your HU output, (2v) and you should be fine. Quote 2009 Cobalt LT Pioneer Headunit 2x Pioneer 6 1/2 (stock amp) 2x Pioneer 1" tweeters (stock amp) 2x Pioneer 6x9 (stock amp 4x Pioneer 6 1/2 Pioneer GM-6400F Soundstream DTR 1700 R.I.P 2x Champion series PRO 12" subs 0 AWG Big 3, Stinger SP1700 battery To come: New or repaired DTR!! Link to comment Share on other sites More sharing options...
LZTYBRN Posted January 18, 2011 Author Report Share Posted January 18, 2011 Sweet, sounds good, thanks a lot for the help. Unrelated question: (doesn't really deserve its own thread) Is there a way to measure dB's at home? Quote Link to comment Share on other sites More sharing options...
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