Out of phase question

 

Silver Member
Username: Dpaw20

FL USA

Post Number: 119
Registered: Mar-05
Ok, so I did the battery thing and i did one sub at a time (ive got 2 alpine type r's) and each one went in. I did both at the same time and both went in. Should they be going out instead of in? When they're hooked to my amp and its playing, one of them seems to be moving a tad bit slower or behind the other one. Im confused here so anyone who knows about this please help.
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 525
Registered: Nov-04
you prolly had the polarity backward if both went it.
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 526
Registered: Nov-04
**you probably had the polarity reversed if they both moved inwards instead of outwards.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 120
Registered: Mar-05
polarity? How do I change that?
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 528
Registered: Nov-04
just flip the battery the other way.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 121
Registered: Mar-05
so my neg wires actually pos wires? Do I just put what I though were - wires into the + on the amp and vice versa?
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 531
Registered: Nov-04
yeh.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 122
Registered: Mar-05
did that, and the subs looked even more out of phase playing. Im just going to get a professional to do it.
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 7607
Registered: Dec-03
it doesn't matter if they go in or out as long as they move the same direction at the same time.
listen to the subs. switch phase on the amplifier 180 degrees and listen again.
whichever way has the best response, leave it that way.
problem solved.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 123
Registered: Mar-05
its not that simple. Every way I wired them (without switching the wiring inside the box on the actualy subs) they look out of phase. I wired them the right way I think, but I want to feel like everything is right anyway. This being my first system Ill always be worrying about things. I want to get a professional opinion on everything and be done with it. Thx for all the help guys.
 

Silver Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 946
Registered: Sep-04
I hope it ain't that Obcon box.

:P

Did you purchase both those Alpines new from the same place? If you did you might want to check to make sure both's voice coils are wired the same especially if it seems you're getting more excursion from one. If you've got a multimeter just measure the resistance at each terminal cup. They should be close to the same for each sub.

Also if you're running those subs with two separate channels you might do better rewiring the voice coils or subs in series and bridging the amp. They're might be some funky things going on if you have unbalanced output to each as they both "share" the same port.

-Fishy
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 7611
Registered: Dec-03
my opinion is professional!
haha

you have two DVC subs. are the coils wired in parallel or series? are the subs wired to the amp in parallel or series? is this a mono amp you're using?
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 124
Registered: Mar-05
mono amp and it should be in parallel. Is it possible to draw a picture put it in the thread? If I could show you you could tell me if it's right or wrong. Also, if my subs have 8 gauge terminals and im using 12 gauge speaker wire would that have any effect?
 

Gold Member
Username: Subfanatic

Walton, Ky

Post Number: 2141
Registered: Dec-04
it would just restrict the amount of power going to the amp
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 125
Registered: Mar-05
do I need 8 gauge wire?
 

Gold Member
Username: Subfanatic

Walton, Ky

Post Number: 2144
Registered: Dec-04
dont need it, im running 8 through my whole system and i need like 0, im just looking for a cheap place to order a bunch of it lol
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 126
Registered: Mar-05
good
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 7619
Registered: Dec-03
for speakers you don't need anything more than 14awg. speakers are a high voltage, AC circuit. you don't build up heat in speaker wire the way you do in high current DC voltage circuits like amplifier power and ground wiring.

take the subs out of the box.
make sure you have a jumper wire from positive to positive and another wire from neg to neg on the terminals. that'll have the coils in parallel.
then connect the box terminals to one pair of the pos/neg terminals.
wire both subs directly to the amp pos to pos, neg to neg.
that's straight parallel, in phase. set phase switch to "0" degrees on the amp.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 127
Registered: Mar-05
I kinda get what you said but not really. I have it wired like this: I have a jumper wire on a set of +,- on the same sub for both subs. Then with the remaining + and - on each sub, I wired them to the box, then from the box to the amp. Man a picture from paint would help a LOT, but I dont think you can on this thing.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 128
Registered: Mar-05
Actually, it might not be parellel, but the subs are dual 2ohm VC and wired to 2ohms (or im trying to lol).
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 129
Registered: Mar-05
whats your email so I can send the picture to you?
 

Silver Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 948
Registered: Sep-04
Hmmm.. If you have just one single wire going from the pos of one voice coil to the neg of the other then you have the voice coils in series and the subs in parallel(the dual speaker connections on mono amps are common to each other) for a 2 ohm load total. Look here:

http://www.jlaudio.com/tutorials/wiring/index.html

Does it look like the 3rd diagram from the top except for each sub going to a separate set of outs on the amp?

If so you have everything wired right if you're looking for a 2 ohm load.

Since you have two ports on that box(one going to each sub) that are connected to one larger port maybe you're getting some oscillation of the air mass which effectively connects the two chambers. I would think that could exagerate any slight phase differences between the two subs. I'm not at all familiar with that type of ported enclosure. Maybe Glass or one of the other pros could take a look at that box and give us some input.

Here's the thread:

https://www.ecoustics.com/electronics/forum/car-audio/132200.html

Here's my impression of that obcon box's configuration:

http://home.comcast.net/~guppyrig/wsb/media/322068/site1083.JPG

Is that about right D P?

-Fishy
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 7632
Registered: Dec-03
oh you have dual 2 ohm coil subs. ok.
you have one set of coils wired + to - and the other set of coils wired to the terminals on the box, for each sub. that's series, which gives you 4 ohms at each speaker terminal.
wiring both speaker terminals on the box directly to the amp would give you a 2 ohm load.
that's all correct.
if you want to test each sub's polarity using the battery, just be sure both subs move the same direction when you connect the battery.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 130
Registered: Mar-05
http://www.jlaudio.com/tutorials/wiring/index.html the third one down is how I have my subs wired. Im trying to get them wired to 2ohms. My subs are dual 2 ohm. Are they wired right?
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 131
Registered: Mar-05
and yah fishy, thats what the box is like
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 132
Registered: Mar-05
Fishy, I have a mono amp. There's only one set of outs on the amp. I put the + from each sub from the box terminal to the + on the amp and same for -.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 134
Registered: Mar-05
bump
 

Silver Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 968
Registered: Sep-04
Yeah you're cool.

If you'd like to test whether that port configuration is causing a phase problem try clogging up the inner ports real tight with a couple rag's or some other fairly dense material

If the subs still appear to be playing out of phase then the port probaby isn't the problem. If there seems to be an improvement take out those rags and try it with the outer port sealed. If you're still good and are liking the way it sounds you might want to think of sealing the outer port more permanent-like, say with a piece of mdf and a few drywall screws.

Sealed will give you less ouput, but may sound a lot nicer.

-Fishy
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 135
Registered: Mar-05
yah, I went to some guy today (not car audio store) who is a electrical engineer, but didnt know s*hit about car subs. He didnt even know how to set the gains. He set them real low because he said "any louder and the windows will break. This car isnt made for that (its a 2000 Jeep Grand Cherokee"...so he dont know what hes talkin about. Im ganna go to the car audio store and see what they think.
 

Silver Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 973
Registered: Sep-04
Try the rag trick.

If you clog those inner ports tight enough it will emulate a sealed enclosure fairly well. You could try just sealing the big port but you'd effectively still have a "port" connecting the two chambers.

A port between two equal chambers would have a resonant frequency close to that of the same port playing in half the volume of one chamber. I know this isn't your typical port connecting both chambers(you have the external vent as well), but its similar. How similar? I honestly don't know, but with a typical "chamber connecting" port if the two drivers are out of phase around this resonant frequency I'd think this port's airmass could begin sympathetic vibration, alternately "pushing" on one sub while "pulling" on the other.

I wouldn't think this would be a good thing and could exaserbate phase differences and posssibly lead to some cancellation around this frequency. I really don't know how much this would effect how it sounds, but could explain why your subs look like they're playing out of phase.

It could be just that they're actually slightly dissimilar drivers. However, clogging up those internal port openings would pretty much remove that thing from the system.

Taking your system to a shop may prove fruitless unless you find someone who's had some experience with this type of port configuration or if this phase problem's cause lies elsewhere.

Lol, any of that make sense? Even if it didn't you could satisfy my curiosity and try sealing those openings.

I really think that looks like a cool port setup. Its simple, doesn't effect driver depth, yet still stiffens the center of the enclosure. I'd like to try it, but not if it has issues which could lead to reduced SQ.

:-)

-Fishy
 

Silver Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 974
Registered: Sep-04
After thinking about it some more those subs would have to play at least 90 degrees out of phase for there to be any cancellation(unlikely), but your subs could alternately unload slightly at high volumes which wouldn't do much for sound quality.

I wish someone here who knew more about this stuff could comment. I'm really just guessing here.

Where's Richard Clark when you need him?

:P

-Fishy
 

Gold Member
Username: Invain

Michigan United States

Post Number: 2079
Registered: Aug-04
Yeah really. Him and his 100" sub. I'm sure he might know a thing or two.
 

Bronze Member
Username: Erushnak

Post Number: 18
Registered: Oct-04
I borrowed 2 10 type e alpines awhile ago from a buddy and they bumped better then expected. Anyway though, they seemed to be way out of phase at a high level but lower it looked normal. After playing with the wiring and confirming I had done it correctly I just left it as is and they sounded just fine.

If you ask me I'd say don't worry about it as long as they sound fine, it may be some wierd thing with alpines, on purpose or otherwise.
 

Silver Member
Username: Dpaw20

FL USA

Post Number: 143
Registered: Mar-05
man, my box is tuned too high. Obcon never emailed back, but on the song "You Run It" by Three 6 Mafia I figured out that you can just bairly hear the lowest sounds. It'll change in bass lines, it'll go................."BOOM(Higher)--BOOOOOOOM!(Middle low)--hardly heard from subs...(lowest). Some songs sound good, but some with the lowest frequencies just dont get loud. Hope all that made sence lol.

Also, sometimes it sounds puncy, and not boomy and I know it's suppost to be boomy. How do I stop that/fix it?

I want to build my own box, but im affraid it would be too complicated. I got most of the tools I think i'd need, but I dont know how to do it. I could probably do the construction, but I have hardly an idea of what design, size, etc. Maybe I'll just save up and get a custom...I dont know.
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