identical subs sound different
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=20499
Printed Date: May 10, 2025 at 12:34 PM
Topic: identical subs sound different
Posted By: Ketel22
Subject: identical subs sound different
Date Posted: October 23, 2003 at 9:33 PM
i have two identical kappa perfect 12.1 and when i play each one alone they have a seperate tone, one is higher than the other. if i play them together the sound is lower and spl is lower than with only one sub, i am running the off of a rockford power 1000a2.
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Replies:
Posted By: bberman1
Date Posted: October 23, 2003 at 9:40 PM
Are you sure they are in phase?
Posted By: Ketel22
Date Posted: October 23, 2003 at 9:59 PM
how would they be out of phase? im just confused beyond belief right now, ive never had this happen before, the subs are in a shared box with a seperation brace in the trunk of my mothers 03 altima. its a rockford 2channel amp rated and 275x2@4ohm the subs have a rms value of 350 and are svc 4ohm subs. this phase thing is completely new to me, plz help. ------------- Quad L Handyman services
Posted By: nedgeworth
Date Posted: October 23, 2003 at 11:21 PM
What phase reffers to is make sure you have the - of the amp going to the - of the sub and likewise for the + side. Also do you have the same problem when running the sub of the same channel on the amp?
Posted By: wvsquirrel
Date Posted: October 24, 2003 at 12:12 AM
The different tones could come from several things, like manufacturing defects in the sub and/or small differences in the chamber sizes of the enclosure. Are you using a Ported or Sealed enclosure? If you're using a ported enclosure, the ports may be tuned differently.
With phase you have 2 settings, 0 and 180 degrees. With 2 SVC's wire like nedgeworth said: + to + and - to - running 1 sub per channel (stereo). ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
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Posted By: Ketel22
Date Posted: October 24, 2003 at 2:17 AM
the subs are in seperate chambers of a sealed enclosure. what can i do to trouble shoot this problem? i will try running them off the same channel this weekend. ------------- Quad L Handyman services
Posted By: wvsquirrel
Date Posted: October 24, 2003 at 2:28 AM
try using the same chamber for each sub, as well as the same channel from the amp. When you were only running 1 sub were you just using the right or left channel, or did you bridge the amp?
If you use the same chamber and same amp channel to run each sub (1 at a time), then more than likely any differences would be due to a manufacturer defect or minor difference in the subs. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
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Posted By: Ketel22
Date Posted: October 24, 2003 at 2:45 AM
i am using the amp in stereo, so i need to take both and and listen to them in the same chamber on the same channel. is that correct? and if there is a difference, i sould be able to get a new sub yes? ------------- Quad L Handyman services
Posted By: DYohn
Date Posted: October 24, 2003 at 7:28 AM
You are probably hearing the differences beyween the enclosures, possibly aided by differences between the amp channels. Run the speakers in mono - if you can't bridge tha amp because of impedence loading, at least set the gains at the same point - lowest possible setting is best - and be sure you are sending a mono signal to both channels. Is the crossover for both channels set to the same frequency? Send the subs a test tone and see if they both reproduce it properly. But, the biggest thing that can affect the SQ besides the driver itself is the enclosure. Slight differences in size, damping, porting, speaker mounting, etc. can make a big difference in sound. I'd bet you don't need a new speaker as much as you need to correct problems in the enclosures and/or the amplifier setup. Besides, if you listen to them both and they both work but sound slightly different, which speaker is defective?
Posted By: wvsquirrel
Date Posted: October 24, 2003 at 7:42 AM
Yes, listen to them from the same channel and the same chamber. To isolate an enclosure issue, listen to them both from the same channel and the same chamber, then use that same channel but switch chambers. If the subs sound the same in one chamber but not the other, then you've got some tweaking to do with the enclosure. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: nedgeworth
Date Posted: October 24, 2003 at 9:32 PM
Well Wvsquirrel has said everything i was going to but i had to leave work! But i'm in total agreeance with him. (Excuse the spelling)
Posted By: Ketel22
Date Posted: October 26, 2003 at 4:03 AM
alright i went and messed with the gains, the subs sound the same now, the only problem that i have is that when i have only one sub on the bass is lower and louder, when both are on the bass becomes quiter and higher.? ne clues?
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Posted By: DYohn
Date Posted: October 26, 2003 at 7:49 AM
You must have something out of phase.
Posted By: Ketel22
Date Posted: October 26, 2003 at 4:03 PM
how can i have something out of phase? i dont understand this whole phase concept?!
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Posted By: ualrbaseball
Date Posted: October 26, 2003 at 9:59 PM
First of all, are you running the subs parallel or running a sub to each channel. Another thing is that you should check the ohms on the subs to see if they are reading 4ohm. The reason I say this is because I have 4 Infinity Kappa Perfect 12's in my Explorer.
Posted By: Ketel22
Date Posted: October 26, 2003 at 10:03 PM
I am running the subs one per channel, what do you mean by "Another thing is that you should check the ohms on the subs to see if they are reading 4ohm. The reason I say this is because I have 4 Infinity Kappa Perfect 12's in my Explorer. " ------------- Quad L Handyman services
Posted By: ualrbaseball
Date Posted: October 26, 2003 at 10:11 PM
The reason I say that because if one of the subs is reading lower than 4ohm then it will recieve more power than the sub that is reading 4ohm. Less resistance means more power for the sub.
And in my case if 1 of my 4 subs was reading less than the rest than one set of subs would recieve more power than the others creating a different sound.
Posted By: Ketel22
Date Posted: October 26, 2003 at 10:14 PM
after messing with the gains and setting them properly both subs sound the same, now the problem i have is that when i have one sub on, doesnt matter which, the spl is higher than when i have both on. like if i put the right RCA the right sub is loud but if i put both in its quiet again, if i plug in only the left RCA the system is loud again. any ideas? ------------- Quad L Handyman services
Posted By: aggie altima
Date Posted: October 27, 2003 at 1:00 AM
Just adding my 2 cents on the out of phase concept. I had the same problem, and I couldn't figure it out either. What I didn't realize was that I accidentally wired one of my subs the reverse of the other one, meaning the positive terminal of one of my subs was going to the negative connection of the amplifier while the other sub was wired correctly. What this did was make my subs travel in opposite directions, practically meaning one was pushing in and one was pushing out. Just make sure that your wiring for each sub agrees with the other one. Follow each terminal of the subs and make sure they go to the corresponding terminal of your box, and that each terminal from the box goes to the corresponding terminal of the amp. I know it sounds like something simple, but believe me, its something simple to overlook. Sorry if this was no help.
Posted By: Ketel22
Date Posted: October 27, 2003 at 1:21 AM
yeha actually while messing with the gains i touched each of the cones with one hand to check this
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Posted By: Ketel22
Date Posted: October 27, 2003 at 11:13 PM
any more help, i really want to get this solved asap, if not im stuck with one usless sub that i didnt have to pay for.
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Quad L Handyman services
Posted By: DYohn
Date Posted: October 28, 2003 at 7:42 AM
The only way that I know of that sound level becomes reduced when you play two subs vs one is that they are out of phase with each other. If each sub sounds right by itself, you do not have defective equipment, you have a defect in the installation. "Phase" means either exactly what aggie altima said: when one speaker is moving out the other is moving in and they are cancelling each other, OR if they are both electrically in phase, it is possible the sound waves are cancelling each other due to speaker position, car interior geometry, or any number of other factors. Here's what I suggest you try: Ensure the speakers are electrically in phase starting by ensuring they are connected correctly + to + and - to -. Trace the wires by hand from the speaker terminals to the amp. Check your feed to the amp. Is it running off a pre-out from your deck or are you using high level signals and a LOC? Check you amp and see if it has a set of "phase" switches and if so, make sure they are set to the same position on BOTH channels. Make sure you are sending a mono signal to both channels of the amp and that it is the same signal. If all this is OK and you still notice cancellation, try moving the subs around. Are they in the same enclosure? Sealed, vented, bandpass, what kind? Try re-positioning it, point it in the oposite direction, make sure there is the same distance from both drivers to the nearest thing in the car directly in front of them, make sure the ports are the same length and not obstructed either externally or inside the box, etc. If they are in separate enclosures, make sure they are not pointing at each other in addition to the above. Good luck!
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