I recently hooked up a sub all the way at the end of the trunk. now, on some faster music, I noticed the bass sort of lagging behind the rest of the music. now, I've heard about type 4 ported boxes lagging because the bass has to bounce and come out of the port. but this is a type 1 sealed box. any ideas?

I also noticed the right and left channels of the rca pair to the sub were swapped... does this affect anything?

 

Hey miwa...

I had the same problem when I first installed my sub. I drove for a while like that, but it became unbearable. So, what I did was (I don't know if this is your problem, too) rewire the the sub. I have JL 12", and the wiring diagram was a bit confusing, but I rethought the wiring, and rewired it, the way that the diagram showed, and it worked fine. No more lag for me...I listen to trance and stuff, and I noticed the lag on these tune the most...Try looking at the diagram again. Don't know which subs you have but for the JL, there were like 6 different ways to wire the damn thing...go figure.

Hope this helps.

 

yes!! exactly.. its showing up on atb's dedicated. :o fast paced music. it seems like the sub is playing catchup. alright, I'll go take a look at the sub's wiring . I have an alpine type S. what did u end up wiring your JL for? two ohm? four ohm?

thanks

 

4ohm, I think...it was a while back so I don't recall...I think I had to wire it in series, but I had it wired in parallel. Not quite sure how or why this works, but if it works...I guess...

Trance was the main problem. Also, I noticed that after rewiring the sub, it wasn't as loud. But I'm sure I have to play with the gain and all that stuff...

 

People sometimes wire speakers out of phase when they have issues like this. A simple way to do this would be to flip positive and negative on the SPEAKER wire as it comes out of the amp. Some competitors wire one side of the front soundstage out of phase to use this "delay" to their advantage.

David

 

hrrm.. that probably explains why when I did a phase reverse on sub output on my head unit, it seemed to have gotten slightly better.. but if I try, I can still hear the lag. I will doublecheck the wiring this weekend. maybe the guy set it on 2 ohm resistance and its getting 300watts of rms power instead of the 200rms that it 'likes'. maybe its over-powered and lingering on stuff from all that excess excursion?

 

Superdave is right...I, too, thought that it was the positive and negative reversed, but thankfully that wasn't my problem...Since I still had lag PLUS it sounded horrible when I tried to reverse the polarities...The wiring fix, I did by chance, and it worked for me...I hope it works for you too...It's sounds MUCH better without the lag...

 

I thought of one more thing that could be causing the time lag you are talking about. It is possible that you have the sub playing too high and it is pulling your attention to the back of your car. Low frequencies of about 60 Hz and down are largely non-directional as far as our hearing is concerned. As you make the sub play higher than 60 Hz, you will notice the subs placement more and more. Competitors often deal with this by getting bass up front, which just means they add a midbass speaker to play down to about 60 Hz and then pass everything below that to the sub. If you have a variable crossover, play with it and you will see what I mean. Good luck getting it to sound good.

David

 

I would first switch polarity on the sub and see if this helps. Then like Superdave said, lower your gain a bit. If it is too high your creating mechanical noise (everything else in the car starts to vibrate and hum when the bass hits leaving the preception it's the sub when its not- its the rest of the car resonating afterwards). Also lowering the xo point may be the trick also. Only do one tweak at a time to determine its affectivness.

 

hemoglobin: I reversed phase with the wires physically today and .. well.. the effect was the same as doing it with the headunit .. it works.. but on a few types of songs .. u could hear it if u tried .. most trance is okay so its bearable.

I then put the wires back the way they were and left the phase at normal. I then proceeded to reverse phase the interior speakers based on what superdave mentioned earlier. I think this produced the best effect.. better than just reversing phase on the sub. now I have to try hard to hear the lag on the same song. Its there.. but not as badly noticeable. I think this worked better cuz it allowed the lows to finally make its way to the front while the interiors were busy "lagging"

in a better world, I'd have an alpine DSP to handle time delays.. but I guess I'll live with this its good enough. I have yet to hear it on my dream dance cd tracks. that ATB - dedicated track was just weird I guess. with this solution, even the second atb track that did lag .. doesn't lag anymore.

superdave: it wasn't just a "notice placement" type lag.. it was like "off sync" style lag .. I think it was so far to the end of the car that it takes waay too long for the bass to travel. so the phase solution worked out better.

brewboy: I've known about the XO bit .. but I wasn't aware of the phasing bit. so anyway.. resonating lag... interesting theory. that might be why it sounds better with less bass. yea.. my gain is already down. I look for clean sound versus 'rock the block', but lowering the bass level a little bit did improve the issue a bit too.

thanks to all who clued me in on what phasing was and all the other possible solutions. it sounds good now Enigma's 1990 cd plays pristine. Friends freak from the clarity of the system. I'm happy ..

 

Glad to hear everything worked out. Good job.

David

 

Miwa, not sure what you did on the fronts concerning polarity, but it is most common to reverse phase on the mid-bass driver on the passenger's side only. The tweeter on the same side is wired normal polarity. Don't know if you can do this with your speaks, can do them on the xo?. I have reversed phase as described to widen the "sweet spot" staging with good results. Good luck.

 

well.. I reversed the polarity straight out from the amp because it was the easiest place to do it. from there, I guess everything in turn got reversed. I did only for the passenger side originally and yes.. it sounded amazing in the driver's seat but it sucked for the passenger. Seeing that I'm a sharing kind of person, I decided not to go that route. I ended up doing it for both fronts and realized that it sounded good. I then did it for all the interior speakers. So far, I haven't heard any adverse effects. If you know of any, please do tell now before I bust up my components!! thanks..