I've had this setup for a few years now and it just hasn't ever really been all that loud and deep, so... I'm here for help.
My setup consists of the following;
Alpine CDA-9833 (4 Volt preamp output)
Infinity Reference 611a which puts out 657+RMS at 2 ohms.
(2) Infinity Kappa Perfect 10.1 subs 350RMS each
MTX Bass Slammer box (Trapezoid shaped w/ .65 cu/ft per chamber)
Streetwires 4ga wiring
Lanzar 1.2 power cap (some say they help, some say the don't, some say they act as a voltage leveler. All I know is that I got it due to my old setup dimming the hell out of my lights and this new setup with this cap doesn't unless I use two or more power windows at the same time. However, the old amp was an A/B Class and this Infinity is a D Class, which supposedly causes less strain on the electrical system)
Now the specs of the subs call for a sealed enclosure of .6 cu/ft, but I ended up get a .65 cu/ft (per chamber) box. Doing this I'm sure changed all the other specifications for the box, but I went ahead as if the box was merely .6 cu/ft and lined it with 1" of polyester batting bought from Wal-Mart (I think/thought the batting I bought is about the same thing as fiberfill). Again, since the enclosure is .05 cu/ft larger than specs called for, I may have caused more issues lining the box according to specs. After all these years I'm just not content with the bass output of these subs. My amp gain is slightly above 1/3 of the way, the low pass is about in the middle(however it is at 80Hz on the HU), and the DBO is adjusted somewhere in the 30-50Hz range with the boost half way up. As for the HU, most of the time it is on the Rock setting (mostly because I just can't seem to tweak the EQ by ear), if not Rock then the Flat EQ setting.
Now for anyone familiar to alpine HU's I generally listen to it from 12-16 with the bass level anywhere from 8-13. I know I could just turn the volume up higher if I want more bass, but most songs have the speakers screaming at volume level 15. As for turning the Sub level up to 15 I just never felt it was good to max the volume out on anything (just a little pet peeve of mine).
If there is any other information I left out that might be of help let me know.
What a coincidence, i have the same subs running off the same amp! I don't think you're box is too big. However, i get a lot more deep bass from my subs by porting them. Look at THIS response plot, and you can see what a dramatic difference it makes. At 30hz, the ported box is 6.5 db louder than the sealed. If it's deep bass you want, the only way to go is ported. I love my old infinty subs, and they raise hell in the right enclosure.
They are good subs, they sound very clean in my sealed box, they just don't seem to hit as hard as I hoped. My old JL 10w0's seemed to hit just as hard and on a mere 97 watts (well more than that since the amp was CEA compliant) Also, thos were only rated at like 85 dB vs. the infinity's 94 dB sensitivity. As for going with a ported box, no room. The sealed box I got barely clears the rear speaker baffles.Unless I built the box myself I wasn't able to find one that would fit and I have little knowledge on building sub enclosures. My next setup will likely sound much louder since I plan on using Second Skin in the car. My current setup doesn't have any sound deadening material installed and so I'm sure I'm loosing a few decibels from frequency cancellation. Believe me, even though I don't feel it's hitting as hard as it should, my car rattles like a paint can. Corsica's weren't meant to have systems.
Having said that I guess I may have answered why it is my subs aren't hitting as hard as they should. However, I am hoping there is something I can do, other than spending $250 to sound dampen my car, to improve the bass. I don't know, maybe I was hoping someone would be like, "Hey, you need to set the low pass to X, the DBO to X, the boost to X, the gain to X, and the HU needs to be set so and so." But I know no one can do that since there are too many variables.
As for that graph, the sealed box appears to be 1.236 cuft while the ported is 2 cuft., this must mean they had two subs in the enclosure, right? Where'd you get that from? Any idea what the power is feeding each setup? Also, any clue as the where the subs are mounted? in a room doing a bench test? In a car? Do you know if both boxes are built to Infinity's specs? Also, it looks as though the ported ones are playing frequencies all the way up to 1kHz, which can't be true. Given how flat the response curve is I can only assume they are being tested in a lab or something since a car wouldn't allow such a flat response.
I'm not so sure why I'm wanting to know so much. I already know that ported enclosures are louder than sealed enclosures.
You should set the lowpass on the headunit or on the amp, but not both.
The graph i linked is for 2 subs, and the response plot is 647 watts at one meter, in open air. It goes to 1khz for every sub, but frequencies above 100 hz aren't affected by the enclosure, so just ignore anything above that. On my amp i have the subsonic filter set to 27hz, and the DBO at zero. That doesn't help you much, because you're using a sealed box. The head unit equalizer is flat, the bass boost is at zero, and the sub level is set to zero. I can't tell you where to set your gain, it requires some trial and error. It depends how strong your RCA signal is. The amp has a clip indicator light, so if that's coming on you know the gain is too high. Occasional flashing is okay, a solid light is definitely bad. The DBO boosts frequencies based on where the subsonic filter is set, so try adjusting your subsonic filter up or down.
Sensitivity settings are pretty useless. That 93 db rating is for a ported box. The sensitivity for 1 watt/ 1 meter in a sealed box is around 87 db. Even that isn't a very good indicator of how loud it will play.
Ah, so those weren't in a vehicle. I thought being inside a car would yield different results than that since some frequencies get a boost and others don't due to the vehicle's acoustics.
You must have your box tuned somewhere around 30-35Hz, right? I have my DBO set around 45Hz since I've always liked the sound I got from my other amps that had fixed boosts at 45Hz. However, since I haven't a clue as to the exact frequency it's set at I may just go ahead and turn it down to 20Hz and the boost to 0 and hear how that sounds(the subs are supposed to be able to hit as low 18Hz if I recall correctly). As for the HU EQ, I use Flat now and then, so that's not a problem to use and the boost is always off anyways. However, the sub volume level can't be turned to zero or else I'll barely hear the subs. Now with the gain, my HU has a 4 volt output and the amp can handle up to what, a 6 volt input? I may not have the gain up high enough, but I didn't want to have them distort so I stayed low. The clipping indicator light has never once lit up (to my knowledge), so I'm sure the gain isn't too high. Problem is that I have, in the past, set the gain higher, but even at 3/4 of the way up I didn't notice any distortion. I'm just afraid to ruin the subs and/or amp because I wasn't able to hear that there was a problem. I guess I could go ahead and crank the gain up again and just stand there while I play a few songs with intense bass to see if the clipping light comes on at all. With my luck, the **** light is burned out, even though I bought it new.
Correct. Infinity recommends tuning those subs at 35 hz, but i prefer lower. If you set the subsonic filter to 45 hz, then all bass below that frequency will be filtered. That's cutting out quite a lot of material. A 6.5" sub can go deeper than that. You could probably go without a subsonic filter at all, but i don't think there's a way of defeating it on that amp. Definitely try it lower than 45, and give it a bit of boost if that's your thing. Hope that light is working!
Noooo!!!! I messed something up a short while ago. I decided to reset the gain and crossovers on the amp and change some on the HU. I turned the gain down on the amp, LPF to 32, DBO to 20, boost to 0. Then on the HU I turned the LPF to with a slope of Flat to bypass the filter. Turned the volume up to 20 and went to set the gain, at just over 3/4 gain I saw the clipping light start blinking, so it works. I backed the gain down to half way and the light no longer blinked, but there seemed to be a good amount of bass coming out and causing all sorts of distorting rattles from the car(I never listen to audio at that level). I thought at first the LPF on the amp must have issues beings that it was putting out a good amount of bass. With half gain I decided to turn the LPF up until I could hear distortion, I don't know what the cut off was at, but it was around halfway so maybe close to 200Hz, at this point the subs were trying to play frequencies they must not have liked because I was hearing all sorts of horrible distortion. I want to say it sounded like the subs were bottoming out, but I'm not certain what that sounds like. I backed the LPF down to about 1/3 of the way, so maybe 100Hz. I still heard that ungodly noise, so I backed it all the way down to 32Hz and I could still hear it some. So now I'm not sure what I did, but I've got something messed up. If I turn off the subs it goes away, but this could just mean that the subs are causing something in the car to make that noise. Now I'm stick with the damage I've caused for being an idiot. Oh well.
This may seem like a stupid question, but are you sure both your subs are connected and playing? If they're in a shared chamber, one could be playing and make the other one look like it's working when it's actually just being pushed around by the other. And did you mean to say you had the subsonic filter(HPF) set to 20? The Dynamic Bass Optimization(DBO) is a bass boost circuit. If you set it to 20, you would certainly get distortion.
Both sure looked to be pounding away when I had the gain up. The two chambers are divided by a wall (it's a MTX Bass Slammer box). However, I guess I wouldn't know for sure if they came disconnected without taking them out to look. I know both box terminals are at least connected to the amp though. If one sub did become disconnected then that would mean the amp was pushing 450 something RMS to a 350RMS sub, which probably would cause it to bottom out and distort. Guess I'll have to take them both out and look. As for the DBO, I thought it consisted of both the HPF/subsonic filter/boost frequency selector (20-80Hz) and the separate boost level adjustment (0-12dB). Anyways, yes the subsonic filter(HPF) was at 20Hz and the boost level was at 0dB
Perhaps it is a body panel making all the racket. Just floating ideas to you. If the subs have their own chamber, it would be obvious if only one was playing.
I don't see an issue with the method you used for setting your amp up, but i could be wrong. You had your volume set to 20, but is that the highest volume you typically reach? The gain should be set with the volume as high as you can get it before your full-range speakers sound bad. The LPF shouldn't cause the sub to bottom out regardless of where it's set, but 100 hz is a good starting point. If you have a head unit that allows you to adjust the sub LPF from the driver's seat, use it.
It may be some part of the car, but it did it even after I turned the gain down to almost nothing (well, .2 volts or whatever the lowest input sensitivity level is on my amp). As for the volume, the Alpine HU goes up to 30, but I never listen to it at levels above 18, EVER. Usually the highest level is 15-16, unless the particular song is very quiet (such as Linkin Park's My December). When setting up the sub amp I turned off the internal power of the HU so I didn't have interference from the rear deck speakers making me think the subs are the ones distorting. Had I left the internal power on I'm fairly sure the Blaupunkt 6x9's would have been distorting (before level 20) on the particular music I was playing, if not, **** would they be screaming. AS for the LPF, I bypassed it on the HU since someone said you shouldn't be using both the amp and HU's LPFs. The amp's LPF can go up to 320Hz, but the subs are only good up to 200Hz, or so the specs say. I'm not sure what the sound was I heard, it was most likely whatever the sound is when you try to have subs play frequencies well above their capability. As I said, I bypassed the Alpine's LPF and used the Infinity's LPF which can go up to 320Hz, but there's no telling on the amp at what frequency you have the LPF set, it only has 32Hz and 320Hz marked. Truth be told, with it up as loud as it was and causing so many rattles in the car I had to strain to hear if it was the subs distorting (which hurt since they were so loud). Because of this, I know I turned the LPF on the amp up higher than I should, but I just couldn't tell if the subs were distorting or not. By the time I was able to distinctly tell it was the subs I had the LPF on the amp half way up or maybe even a little more(I wasn't able to look at the amp with where I had my head).
Weigel21: It may be some part of the car, but it did it even after I turned the gain down to almost nothing (well, .2 volts or whatever the lowest input sensitivity level is on my amp).
It may be some part of the car, but it did it even after I turned the gain down to almost nothing (well, .2 volts or whatever the lowest input sensitivity level is on my amp).
I really hope that is a misprint. .2 volts is the HIGHEST gain setting, not the lowest. Even if you had the LPF set to 1000 hz or a bagillion, the sub will not care. It will play what it can, and garble the higher frequencies.
Yeah, sorry, I got myself confused, I think it just says Min and Max on the amp anyways, I'd have to look. I guess 6 volts would be the minimum then huh. Anyways, it was turned nearly all the way counter clockwise. As for doing anything with the system today, that's out of the question anyways since it's been raining all **** day and I can't pull the car into the garage since it's used as storage of other crap.
If I can't get this setup straightened out then I'll likely just pull the subs so I don't ruin them (if I haven't done so already). Within the next year this car is going to be my winter beater anyways, so it doesn't need a system. Oh, speaking of winter, would the fact that it was fairly cold out when I was setting the amp have anything to do with what happened? I didn't play the music at low volume to warm up the subs before cranking it up for setting the amp. Does pushing a cold speaker nearly to it's limits have any ill effects.