Sorry in advance for the long post, but I want to lay the groundwork for my question. So, this weekend I got my amp rack installed with my two amps all hooked up. I have a PG ZX400ti on my front comps and a PG Tantrum 1200.1 on my "old school" 12" Solobaric. Now I am aware that this is only one 12" sub, and an old, inefficient one at that, but I figured this sub would rock without the help of any subwoofer level adjustments. For some songs I have to raise the sub level on my Alpine 9813 to get the sound I like, which surprised me. Maybe the two amps are putting a strain my electrical system (I upgraded the alt-batt and batt-chassis ground so far)? Maybe my expectations were set just too high ahead of time. Don't get me wrong, the thing "hits" to the point that I can feel the bass when I am crusing at high RPMs (which didn't happen before when my sub was powered by the 400ti). I suppose I expected too much. I am seriously thinking of building a ported box for this sub as a little experiment, as this would give me some more SPL without sacraficing SQ too much With that said, I have NO idea where to start with getting some specs on a ported box for this sub. This topic was explored in the following thread: http://caraudiotalk.com/forum//index.php?s...?showtopic=2865 Michael kindly got me some sealed box specs and like the Kicker manual says, Bassbox pro did not recommend using this sub in a ported box. However, polecat PMed me and said this sub would work well in a ported box (geolemon also claimed the same as polecat). So here is the dilemma - how can I get some design specs on a ported box if software doesn't even give them? I don't want to guess about this, but I am not sure what other options I have besides educated guesswork. Thanks for any advice you guys can give me.
Simply model it up using BassBox or WinISD... I'm sure BassBox won't stop you from modeling it up in a ported box. WinISD is nice in that you can overlay the curves of multiple enclosures... You'll see right off the bat that the sealed enclosure rolls off sooner than the ported enclosure, meaning the ported enclosure will be louder at most frequencies. Your observations might even be frequency dependent... Perhaps the sub rolls off too soon for your expectations, it might even be the sort of system that I generally like in my commutermobiles, but doesn't really have enough "oomph" to rock hard or boom on rap. With that sort of a system, if that's truly what you've ended up with... the SQ should be great (I don't hear you complaining about it), and it shouldn't be a boom-mobile... it should blend well with the music, realistically. If so, don't feel bad about needing to engage bass boost, or increase subwoofer level, to make it boom... of course you'll need to. If it just doesn't seem "quite up there" enough, you could try simply building a larger enclosure for it. Or, you could build the ported enclosure - which will be larger by nature - using a PVC port, which will allow you the option of going to Home Depot to buy a $5 removable port plug, so you can run either ported OR sealed whenever you wish to seal the box off. I'm actually building a box for my Pathfinder right now.. It's going to use three 3" ports. It'll be tuned to about 29hz with all three ports open. It'll be tuned to about 23hz with one of the ports sealed off. And I've got the option to run sealed by blocking them all off. B)
Shitty Alpine Pre-out voltages. Typical complaint. Set your preouts to max and set your gains. Alpine's preout measurement is grossly overrated.
Yeah, I've read that you have to max out the levels on the HU for it to output the "rated" output from the Alpine HUs... But it doesn't really matter... just adjust the gains accordingly... I don't remember what I measured the output voltages at with my HU...
Thanks for the initial thoughts guys. I am thinking I have a little more adjustment on my amp's gains, which would help. I just thought before I ever put this sub/amp combo in that I wouldn't have to adjust the sub level much, if at all. I can deal with overrated pre-out voltages on my HU - that's what the gain knob is for on my amp. As for the SQ of this sub, I am very pleased with it. That is not a problem. It's that extra "oomph" I'd like more of. I am not a bass-head who wants to feel like he is about to vomit from the bass, but I like to feel the pound of a bass drum in ALL my rock and metal music, not just some songs. And in line with what geolemon said, I think certain frequencies come across louder in the box I have now (the factory recommended box). Certain freqiencies roll off too much and a bigger box would likely help alleviate that problem. For instance, I played RHCP "Suck my Kiss" and the bass drum was tight and crisp, but still had a nice punch to it. Songs off Tool's Undertow hit hard too. So I know this sub/amp combo *can* give me the right amount of "thump" I want. I plan on building a bigger box per the specs Michael gave me recently - this would give a flatter response. I want to do that AND build a ported box and have some fun comparing the two to be honest. I will download WinISD and play around with it and see what kind of ported enclosure specs I get.
BTW, thanks for the suggestion. I set my gains with the sub level at ZERO, so I will just go the opposite direction and set the gains with the sub levels maxed out. On an aside, I know most here like Pioneer over Alpines, but so far I am pleased with the sound the Alpine produces, but I would love to be able to hear a Pioneer in my car someday. That is the curious person in me, which could also cause me to go bankrupt...well, maybe not bankrupt, but put a dent in my bank account.
eh, my Alpine's pre-outs are plenty high for me. Beats my old eight-year-old Sony Mobile ES deck and it's 1/2 volt preouts. You don't need high preamp voltages, unless you've got some noise floor that requires a higher Signal/Noise ratio to drown it out... ..but my opinion has always been that's masking, not addressing, the problem.
Yes, the actual RMS voltage output of my Alpine's pre-outs are the least of my worries. As long as I have at least 2 V, then I am happy. Thanks for the feedback though guys - it was very helpful.
