Alright so ive come across a few setups recently that have dynamat or some form of sound deadener inside the walls of the box. is there any gain at all to doing this?
And second, ive tuned my amp with a DMM, but now my subs are hardly hittin. i know this is supposed to prevent clipping? but even at high volumes, my clipping light hardly ever lit. im not sure if im doin something wrong or what
Forget about sound deadening inside the enclosure. Imo...if your enclosure it resonating, you need bracing. "window" style bracing is a far better way to prevent the this.
As for tuning w/ a DMM.....yea....for get about this, for all intent and purpose. I have already posted vids on youtube to show that tuning w/ a DMM or O-scope can mean next to nothing.
The given info online about tuning w/ a DMM is FAR to generalized. It is based on tuning to a 0dB ref 60hz tone for the most part, and I don't know about you, but I have NEVER played a 0dB ref 60hz tone for daily listening.
Setting the gain by ear (if you know what you are doing) is the best method. If your amp offers a clip-light, this offers a secondary method.
If you did set your gain w/ DMM, watch my vid here: http://www.youtube.com/watch?v=SmkWY1e68P8
You can see from the vid, that even though the signal is clean at 60hz, it is VERY distorted at 30hz. (both 0dB ref tones) Box rise/ apparent load to the amplifier will play a major roll in where and when clipping will happen.
The only REAL way to avoid clipping altogether is to have an amplifier that is FAR more powerful than the intended level of play you want requires. If you allow for this, you have 'head room'. So, say you want 1000wrms output at all loads 1ohm (guessing that your nominal dcr is 1ohm) and above. But, impedance may be upwards of 4...or 8...or 16....or 32ohm+++!!!!! Depending on subwoofer enclosure, vehicle acoustics/loading and freq. So....if you want 1000w clean, DMM measurements at 60hz based on voltage from the amp @ 1ohm nominal means NOTHING!!!!
So, if you TRULY want a CLEAN 1000w output from your amp that is wired to 1ohm dcr. You must first have an amp capable of 1000w output at the highest achievable active impedance presented by your subwoofer....given the environment and freq it is presented.
The best advice I can give is "play it by ear". BUT!!!!! Only if you have a seasoned ear!!!!! Otherwise, follow the clip-light!
see im new in this stuff so i dont know if i would be able to hear the distortion since it can be pretty masked by subwoofers especially at low low frequencies. most of what i listen to has some low lows in it. so tell me if this would work: i play maybe a 30hz test tone and turn the gain up as far as it goes until the clipping light comes on.
on the amp i have it as low as it goes at 77hz. but i think theres one in the eq on the head unit and thats set at 60hz so im not too sure
okay heres what i did to tune it: i played the most demanding song i have at the loudest i would ever play my music, and i set the gain so it peaked a little over 54.77 volts at the most demanding point. should this be good? the way i had it tuned before, using the test tone, it was 55 volts at 50hz, 0db, but with any song i have, it rarely peaked over 30 volts
IMO ditch the DMM and don't worry about the volts. You had it right by playing the most bass intensive song you have at max listening volume. Point the subs right at your face and then start with the gain low and gradually turn it up until you can begin to hear note distortion and back it off a little. Then to make sure you haven't gone too far play the subs for a couple good songs and then check the center of the cone to see if its hot and smell for hot voice coils. A little warmth is ok after a good 10 minute session.
well i tried that way, and it seems pretty hard to hear the distortion. From what ive understood though, the point of clipping is at 54.77 volts for a 3000 watt amp at 1 ohm, so i just have it set up so it doesnt go above that much. It seems to be working pretty good so far. my voltage gague is dipping below 13 a lot less than it used to, and it still gets pretty loud
yeah im pretty sure ive got the tuning about right now. its not hittin as hard as id like anymore but maybe that will change once i finish this ported box
imo the dmm is only good for a referance point. taking into account imp rise, voltage drop, and knowing that music is dynamic your never gonna see that amount of voltage except on a test tone. id set it with the dmm then play the best bass song you have and tweak the gain a little untill its right where you want it.