I don't think this is right

[time2kyl]

So, inspired by the loud tunes from last weekend's reunion I've decided to see what is up with my stereo. The amp and tower speaker set up is the same as when I bought it so I've got a couple questions. I'm sure I could find the answer somewhere on here but let's face it, I'm lazy. Plus I'm a mechanical engineer and tried to sleep through all my electrical engineering classes.

So my HU, Sony CDX-R30M 52Wx4 the only thing I've replaced, runs into my amp, Sony Xplod XM-2200gtx. The amp is 2 channel bridgeable.

Output Power:
2 x 200W RMS (20Hz to 20kHz) @ 4Ohm 0.1% THD - at 14.4 volts
2 x 250W RMS (20Hz to 20kHz) @ 2Ohm 0.15% THD - at 14.4 volts
1 x 500W RMS (20Hz to 20kHz) @ 4Ohm 0.15% THD - at 14.4 volts (Monaural)

I have 4 Sony XS-V1635X, 250w peak, 65w rms, 4 ohm in two, what look like homemade, separate cans on the tower, 1 front facing and 1 rear.
Now the interesting part, all speakers come off the left channel of the amp and each speaker has its own terminals on the cans. I've played with the level on the amp and the sub level on the HU, but can't turn the HU up above about 25 before it cuts out. At that level I still can't hear the music when I'm riding and that just sucks. :(

I've attached a picture of what the set up is. Help please so I can :ro: :ro:

[chpthril]

I'll take a stab @ this just to test my own knowlage but we need philwsails or spharis to get in on this :ro:

Ok, if i'm reading this right, you are powering all 4 (4 ohm ea) speakers off of 1 channel of a 2 channel amp, or are they bridged? (out side - and out side + of the 2 channels being used for all 4 spkrs).

If they are powered off 1 channel, with out doing the math, I think that's about a 1/2 ohm load at the amp. That could be why the signal is clipping when you turn it up.

Here is what I would do: Run 2 spkrs (1 can) in parallel to each channel. This will give the amp a 2ohm load per channel. Bassed on your specs, this will give you an output of 250W/channel for about 125W to each speaker. This would require you to run another speaker wire up the tower.

[dogbert]

I agree with chpthril. The bigger problem is that the amp may not be stable at 1 Ohm. Also, each time you reduce the resistance (half the Ohms), you increase the power to the speakers. It's not quite double, but it's getting up there (I'm sure one of the smarter people can tell you the formula). Also, your amp is definitely overpowering your speakers. You might be better off putting each channel in series rather than parallell the way you have it.

[spharis]

but can't turn the HU up above about 25 before it cuts out


That's b/c if your diagram is correct, it is wired at 1 ohm. Thank god it has built in overload protection that is actually working, or you would hvae more problems than you already do.

You need to rewire the stereo the way the second diagram is posted. You should have two speakers on the left channel, and two on the right. Each channel will be wired in parallel, in other words, positives to positives. This will net you 2 ohm load on the amp channels, and give you the best output with lowest noise for the setup.

If you do not want to undertake the routing of new wire to the tower, because the wattage is so low, and assuming you have at minimum 14AWG wire to the tower, you can make some simple changes and get the amp stable, and speakers performing.

You need to bridge the channels on the amp....look at the amp and see which are labeled bridge, and move the appropriate wire t the other channel. In other words either the pos or the neg from the left will move to the pos or neg on the right side. Now go to your tower, and wire the speakers in series-parallel. You want to wire the left cans pos-neg-pos-neg with the wiring, and the same on the right. Then take the input pos and the output neg, and combine them to the appropriate lead back to the amp.


Here is a diagram.....the two connections on the left will bridge at the amp.
http://www.rockfordfosgate.com/rftech/woofer_wizard/4_4ohmSVC_4ohm.gif

Good Luck.

[philwsailz]

Been on the road, and it looks like I am late to this party, but I will agree with most everything written above. You need to get away from the one-ohm load.

Follow CHP and Spharis' recommendations and report back with an update on how the changes worked. If you have any further questions, post here; we can help for sure!

[time2kyl]

I knew I should have been getting better performance. The speakers are not bridged, only coming off the left channel. I'll go ahead and run new speaker wire and get back to you all with the results.

Who knows, maybe I'll just say screw it and buy some new NVSs and call it good :D

[chpthril]

Who knows, maybe I'll just say screw it and buy some new NVSs and call it good :D

Great Idea :ro: :ro: :ro:





But you will still need to rewire :mad: :D

[philwsailz]

I knew I should have been getting better performance. The speakers are not bridged, only coming off the left channel. I'll go ahead and run new speaker wire and get back to you all with the results.

Who knows, maybe I'll just say screw it and buy some new NVSs and call it good :D

Hah!!!!

:p :p Just be sure to wire them correctly!!!! :p :p

[time2kyl]

I just want to know who wired it that way to begin with. The last owner or if someone put it in that way for him.

Time to start saving for Christmas presents for me!!! :ro:

[chpthril]

I just want to know who wired it that way to begin with. The last owner or if someone put it in that way for him.

Time to start saving for Christmas presents for me!!! :ro:

Phil and I know a guy that would, Dont we ;) :rolleyes: :D :ro:

[zad0030]

Phil and I know a guy that would, Dont we ;) :rolleyes: :D :ro:

dont say zad.... :rolleyes:

[chpthril]

dont say zad.... :rolleyes:

Oh no, not you, but a so colled "pro" that Phil knows through the stereo biz and I know because I am having to go behind him a fix a cluster@%#$ :confused: :D

[dogbert]

Been on the road, and it looks like I am late to this party, but I will agree with most everything written above. You need to get away from the one-ohm load.

I think that's the first time I've seen you write that. :D :D

See, some of us do pay attention :D

[chpthril]

I think that's the first time I've seen you write that. :D :D

See, some of us do pay attention :D

LOL :ro: see, you can teach old dogs (no pun intended) new tricks :D

[dogbert]

I knew that was coming :ro:

[philwsailz]

:)