My sub/amp set up...

[lewdog123]

I'm in the process of installing a sub/amp combo.

I've built an enclosure with 1/2" mdf 16.5"x13.5"x5 (outside dimensions)...and it sits perfectly under the rear driver side seat.

I will put one 8" JL Audio 3w2-d4 sub (150w rms) in the enclosure and I plan on powering the sub with a Phoenix Gold Tantrum 300.2 amp(75wx2 or 300x1 rms with 4 ohm load). The sub will be config for stereo mode giving me to proper power that it needs.

I'm only concerned about the enclosure depth not being deep enough. I'm with in the spec for the total volume...but it just doesn't seem right. Anyways...we'll see once the amp arrives.

What you guys think?

 

[DS]

It sounds good, but you're paying for amp power that is going to waste with that particular sub. Why not buy the W3v2-d2? With the dual 2ohm coils, you can series them for a 4ohm mono load for your amp to achieve the 300W output. This power level should be fine, unless you are a user that turns every available knob as far past "10" as possible. I built a box several years ago for a VW GTi that used 3 JL 8's in a vented enclosure with 1200W RMS, and the subs are fine to this day. These are newer subs with higher rated power handling also, so you should have no trouble whatsoever.

 

[lewdog123]

DS,
I totally agree with your comment. I actually wanted to get an amp rated at 200W rms...but it doesn't include the feature that I want.
The Tantrum 300.2 has a knob that you can wire up to the dash and control the sub volume. I had this feature hooked up in my last car with an other PG amp and I loved it. But the 200 and 250W models doesn't come with that feature.

For now I think I'll wire my D4 in series to get 8 ohms and bridge it...that should gimme the 150W that I need. Plus if I decide that I need another sub I can wire them in parallel and get 300W into two subs. Thanks for you input though...I didn't even think about what you mentioned.

-Lew

 

[idocpilk]

The depth is always the limiting factor under the seats. However, there are some nice shallow mount subs, even 10" subs, that are under 4" mounting depth. I have 2 CDT MS 100 10" subs under my rear seats and it is more than I need. If you are just putting in one sub and you haven't bought your 8" you might look around for good shallow 10" like a Cadence Mallet, CDT MS 100, Image Dynamic IDQ version 1...they all will fit in under 4" mounting depth.

 

[lewdog123]

Dang...I already bought the sub and my amp is supposed to be delivered tomorrow. I tested my sub on my friend's system and it sounded better than I had expected it would. Thanks again for your input.
-L

 

[lewdog123]

OK...I gots a problem here and I've come here for help...
I got the Phoenix Gold Tantrum 300x1 amp and wired it up...but the problem is that it seems to not be able to provide enough power to the sub. The volume is waaaaay to low...even the factory speakers are much louder in volume.
I'm pretty sure the sub is fine cuz I tested it on my friend's system. Tomorrow I will try to switch amps with my buddy see it if that helps. Anyways...is there anything I should look for The amp is getting about 14 volts...and the sub is about 8 ohms...I borrowed a voltmeter from work. The blue power led on the sub comes on, but it seems as though it's not amplifying the signal at all...it sux and I am very sad Any advice?? Thanks in advance....
-Lew

 

[DS]

Sorry to hear about your trouble.........There are a lot of possibilities as to what is wrong, unfortunately. Here's what I'd do to try to figure it out:

1. Check the DC input to the amp, which you did and saw 13.8V, which is normal. You're ground must be ok, as the amp is on and would not be without a proper + and - coming in for a complete circuit, and the turn-on must be fine as well.

2. Turn on the electrical system in the truck and the radio. Check you AC input from the line level adapter with a meter, as in the RCA output side. There should be voltage coming from the RCA's, not much mind you, I'd bet around 1-2V with the head unit turned up. It should be fluctuating as well, as this is the amp's input signal.

3. If the amp has DC (12V electrical) and AC (audio input), then your amp's "in" side is taken care of, move to the outputs. Grab your meter and check to see if you have AC voltage coming from your speaker outputs on the amp, with the system turned on and playing of course. If you do measure output voltage, you're getting output for the sub. How much voltage are you reading from the amp outputs?

4. You know the sub is ok, but I'd bet the coils are wired wrong. Common myth regarding dual ( or more) voice coil subs is that if you wire the coils out of phase ( as in reversed polarity), the coils will try to move in opposite directions and tear the speaker to shreds. I know installers who actually believe this which is totally sad to know that these morons are being paid to work on others cars. Anyway, if this is the case, the speaker will just sit still, since it's receiving opposite and inverse AC input, doing no damage whatsoever to it. You may have a bit of output if the amp channels are not identical, ie. one channel is outputting different info than the other channel, which sounds a lot like your problem. Check the wiring again. Use a battery to "pop" the speakers inputs to assure that the sub is labeled correctly if you'd like as well.

If none of that works, at least you'll have info and numbers to work with to try to solve the problem. Good luck!

 

[lewdog123]

I think my amp is screwed up.
I turned the signal sense all the way up and also the bass boost all the way up and I was getting pretty good results from the sub. But the amp got really hot and shut it self down within 2 minutes.
I moved the amp into my friend's car and it did the same thing. I don't think that I'm pushing the amp that hard...my sub is wired up as 8 ohms.
I think I might have a defected amp.
DS...thank's for your advice. I tried to measure the amp input (RCA) but I was getting less than 1 volt AC...even on my friend's system...I could have a cheap a$$ voltmeter. Anyways...I appreciate your help. Thanks.
-Lew

 

[DS]

DS...thank's for your advice. I tried to measure the amp input (RCA) but I was getting less than 1 volt AC...even on my friend's system...I could have a cheap a$$ voltmeter. Anyways...I appreciate your help. Thanks.
-Lew

Most higher end head units will send out about 4volts these days, so getting 1 volt through the Line Output Converter is probably normal. If you have the bass boost and the gain turned all the way up and it is still no doing much but the amp shut off, chech the subs wiring again. That amp should run an 8ohm load all day long without complaint; it's barely working to do it.

For the sub to be configured correctly, just run it like you would to a pair of subs, treating each coil like an individual woofer. In other words, + and - from each amp channel to + and - to each sub input terminal. There is no advantage whatsoever running the amp bridged into an 8 ohm load, it will make the same power or more running 4 ohm stereo.

If your amp has 12V or more, which it should, as its electrical DC input, you're fine.

If you are reading varying AC from the outer ground and center pin of the RCA's, you have input.

If the sub is wired for one channel per coil, you are in good shape. If you wire it wrong or a terminal is marked incorrectly from the factory, which has happened believe it or not, they will be out of phase electrically and just pretty much sit there, so you'll know instantly.

If all of this is done and you still have nothing at all, replace your amp's input with something else, like the RCA outputs of a boombox, portable CD or DVD player, the CD player from inside your home, a laptop's RCA outs and so on. This will allow you to check and see if the headunit's output converter is wired correctly.

Good luck!

 

[lewdog123]

Hey DS,
I installed my amp in my friend's car. His setup has been working fine for over a year. He has an Alpine amp running two 12" JL audio's. He has huge power and ground wire. We just swapped out his amp for mine...he was interrested in how my sounded in his car anyways. We also swapped out his sub with mine...so I was running his setup with my amp...again...all fine and dandy.
At first I was suspecting my head unit or my power/ground lines...by putting my amp in my friend's car I've narrowed it down to the amp itself. I was thiking the same thing...my amp should run and 8 ohm sub all day long without a glitch.

 

[DS]

Damn, sorry to hear that. It's always especially disappointing to get a new-in-the-box product that is basically DOA. Makes you wonder about PG's quality control. However, it happens with cheap pawn shop amps and some of the best amps around sometimes. Hopefully you'll have no problem getting it replaced.

 

[lewdog123]

I'm saying...I recieved it on Friday and Thursday night I could barely sleep cuz I was so anxious to get the thing in my car. Now...I gots to deal with returning it to Sound Domain.

 

[DS]

I'm saying...I recieved it on Friday and Thursday night I could barely sleep cuz I was so anxious to get the thing in my car. Now...I gots to deal with returning it to Sound Domain.

Good luck with SoundDomain. They seem to be a lot like Russian Roulette. I know several people who have had to deal with them on warranty issues. One had no problem and all, one had a little difficulty that got resolved within a single phone call and the other just gave up and called the BBB.

SD sells a lot of factory refurb product, you may have got stuck with a B product without realizing it unfortunately.

 

[lewdog123]

I shipped my amp back yesterday and it should arrive @ SoundDomain on Monday...hopefully everything goes smooth and I get my refund.
I went and bought the same amp from the local stereo shop and I threw it in and it work flawlessly. I am very surprised at the amount of bass that the JL and Phoenix Gold combo puts out. It's prolly cuz the cab is small...you can barely here the bass from the outside...but if you get inside, BAM!! I don't even think I need another amp for the hi's cuz my head unit has a built in crossover...if anything I might swap out the stock speakers for some other of higher craftsmanship.
DS...thanks again for your inputs.
-Lew