Two problems - one message

SiriusBlack · Post by **SiriusBlack** » Mon Dec 20, 2004 8:59 pm

Alright..

So, I'm setting at home doing nothing, and I get a call from my buddy telling me that his subs that weren't due in until Wednesday, have come in today. He asks me if I have a 12" box that he can use for one of his subs, and remembering an old box I had sitting in the garage, I said yeah, and drove over to his house.

We bolted one of his 12"s inside of this box, and plugged it into his home stereo. Immediately, it sounded like s***. So, I came to the conclusion that maybe it needed a break-in session. (I can't remember where I heard about this from, but anyway...) We put in some song from Bass Mekanix and had it on repeat for about 2 hours, open box, and with about half way stretch. I figured that after 2 hours, it would be good. So, I put it back in the box, and hook it back up to the stereo, and get the same crap.

So, I'm setting there wondering WTF could be going on, when my buddy comes up with the plan to put my system back in my car. (I took it out over a month ago so I could sell the car, but I've pretty much talked myself out of selling it) We bring the subs to my house, and spend hours putting my old system back in my car, and finally get my PPI amp and everything set up, and I hook the sub up to my PPI amp, and it sounds exactly the same. I managed to tune it until it sounded a little bit better, but it still has this terrible "BOING" noise to it when it hits. It's not very loud, but you can hear it.

Now keep in mind, we never did get around to testing the other sub. It may be the same thing, and this may just be because it's a new sub. All of my subs have always been used. I chose this route because it was better for me on my wallet.

On to my second problem...

After he left, I hooked my 2 RE8's up to my PPI amp. Everything sounded nice and clean for a little bit, then I shut off the car for a second to run in and get a soda, came back out, put it into acc. and the bass sounded like... I don't know. Anyway, I pop the trunk, and I see that one of my subs is flexing, and the other one is over flexing. I start messing with settings, and I couldn't get them to stop, so I thought maybe it was the RCA's. I start disconnecting them by unplugging the left channel, and... they went back to normal. Everything was fine, but I was running only the right channel. I plugged the left back in, and they went back to crap. So, I then tried only the left channel, and no right. Worked fine.

So basically, what I'm saying... If I have 1 RCA cable plugged in, it's like having 2 and everything works normal, but when I have both plugged in, it over flexes one of the subs, and they both sound like a hairdryer. It's a weird "whururur"ing sound. I didn't have this problem with my buddy's RE12, but I only had his sub on 1 channel, and not both.

Ideas? Suggestions? I'm completely stumped on what's going on. It appears to me that something is damaged in the PPI amp. I have an Eclipse amp I may try later. If that doesn't do the trick, then I have another set of RCA's I can use, but from the looks of it, I don't think it's the RCA's. I tried L on R, then R on L, then L on L and R on R, and no matter how I configure it, if there's only one plug, it works fine... 2, and it sounds like trash and makes this weird noise.

Thanks in advance for any help. I appreciate it, and if you need to know anything or have a question for me, let me know, and I'll get back to you ASAP.

Justin from Detroit1 · Tue Dec 21, 2004 5:59 am

First off, you should never hook up a car subwoofer to a home audio receiver, that's just asking for trouble. A lot of home audio receivers can't even handle the impedance of a car audio subwoofer. You may have damaged the first sub this way. When you were breaking it in (which, by the way, is a process which takes generally 50 hours and the subs should only be played at 1/4 volume) you said you has it "open box". What do you mean? You had the sub just sitting in open air? If it isn't an open air driver (which very few subwoofers are, this could damage the sub, too.

Post by **GlassWolf** » Tue Dec 21, 2004 9:21 am

1: don't run car speakers on a home audio amp. most home stereos are only 8 ohm stable.
2: never run a sub out of a box. it gives no suspension to the sub, and will cause damage. a break in period means running the sub for several hours IN the proper box, at low to medium volumes, without cranking it up.
3: you had no LPF on the sub, which is why it sounded awful.

with your second issue:
1: bad amp ground
2: damaged RCA cable
3: damaged amplifier
it's most likely one of those three.

Mithrandir · Post by **Mithrandir** » Tue Dec 21, 2004 9:28 am

the boing probably means the sub is blown, thats the exact sound i had when i blew my 3 mtx thunder 8000s, i thought you could only damage the reciever by playing a car sub in your home?

progrocker · Post by **progrocker** » Tue Dec 21, 2004 11:38 am

You tell 'em Glasswolf.....er sorry, couldn't resist

SiriusBlack · Post by **SiriusBlack** » Tue Dec 21, 2004 12:09 pm

Geez... I'm so stupid.

I had no idea that it would damage the subs if they were run in open air. As for the home stereo thing, I knew they were 8ohm, but I figured it would switch over. Guess not. I'll try the other sub today if I get around to it, and if it doesn't make the sound, I'll figure the other one is blown/damaged.

Now that I think of it, I did forget to mention that the sub was hooked up to an amplifier for a home stereo subwoofer. Not sure if this makes any difference or not, but I thought I'd mention it. It wasn't just a regular speaker connection.

As for my problem... I'm hoping it's a bad ground. I put a whole stereo (wires/cd player/amp/etc) in my car in around 3 hours, so nothing's perfect. I put the ground in a place where it should have worked, but may not because it's not where I had my last ground. If that doens't work, I'll try the other amp, and if that works, I guess I'll check on getting my PPI amp repaired.

Thanks guys.

Justin from Detroit1 · Tue Dec 21, 2004 1:04 pm

SiriusBlack wrote: Now that I think of it, I did forget to mention that the sub was hooked up to an amplifier for a home stereo subwoofer. Not sure if this makes any difference or not, but I thought I'd mention it. It wasn't just a regular speaker connection.

Thanks guys.

Doesn't matter. Most home amps are made to run at 8 ohms.

Dustin from Huntsville · Tue Dec 21, 2004 1:15 pm

You can run a sub open air like that just fine (not sure why you'd want to do that though other than just to test to see if it works) but you can't send much power to it otherwise the sub will bottom out / over excurt.

As long as your home stereo amp is capable of a 4 ohm load (which a lot of newer ones are....) then it's perfectly fine to do so. If its not able to do so, then ya, it could be bad for the receiver... shouldn't do anything to the sub though.

Have you only been playing the subwoofer by itself? or do you have your mids and highs hooked up as well? Sub-bass playing by itself is going to sound retarded regardless of how great a sub you have.

And as mentioned earlier, if your sub is making a "Boing" sound, then it's probably blown. I'd probably quit messing with the sub before the voice coils unwind all over the place and create a short and fries your amp with it.

And as far as breaking in a sub or any speaker for that matter, I've never seen any empirical data showing a benefit of doing this. I used to think it was needed and made a difference, but it seems to be a bunch of crap now. It's just something the so called elite 'audiophiles' have made up. Same as the need to break in your RCA or XLR lines with a special machine or using a magic marker on your CD to make it sound better, or a special ink that you can put on your resistors to make the music more transparent. Funny stuff

SiriusBlack · Post by **SiriusBlack** » Tue Dec 21, 2004 4:46 pm

Thanks a bunch Dustin,

I called up my buddy and he says that he thinks that the "boing" noise is actually an air leak around the mounting points. There's this thick carpet that's on the box and I think if we tear it off, that might stop the noise.

I really don't think the sub is blown (nor do I want to think that). We had the sub on a cheapo Regent surround system from Wally World. I'm pretty sure it's 8ohm. We didn't have the sound up loud enough for the sub to bottom out (for whatever it's worth), because I know exactly what this is like. I tore up an older Sony Xplod like that... on purpose :woohoo:

BTW - the reason we had the sub "open air" (out of a box, running) was to test it to see if it worked. Then, like little children, we became amazed at what we saw, and continued to play.

Thanks guys.

Jszar · Post by **Jszar** » Tue Dec 21, 2004 5:36 pm

its important to remember that if you aren't sure of what you're doing, ask questions first before you do something. you could have, if you haven't already, blown the sub and/or damaged both your car amp as well as your home amp. this is a good lesson to learn from, just take it as that.

btw, most people here get to the board ever couple hours. so next time you have a question post and be patient. depending on the company, most won't take products back if they were't installed by a certified installer, or if they can prove you installed it improperly. if that happens, you're at a loss of money.