Ohms Question For Experts

Hy everyone, I've got a novice question which I need help on...I'm currently running my front stage with a 4ch amp at 60wrms(stereo) at 4ohms using the front 2chs. I was using the rear chs on a pair of coaxils, now they are just waiting to be filled in. I will be using deck power instead on the coaxils and will run these rear chs bridged(200wrms/mono) on a 8" midbass driver instead to get a 3way system up front. My question is that my amp is stable down to 2ohms at 100wrms(stereo)...how do I configure my setup so that the front chs will be putting out 100w(stereo) and the rear chs 200w(mono)??? Please help me out brothers!!!! BTW, my amp is a PG T400.4, front stage is Boston Rally comps.

I checked the specs at Phoenix (Tantrum 400.4), and you can do 50rms x 4 @ 4 ohms, 100rms x 4 @ 2 ohms or 200rms x 2 @ 4 ohms(bridged). I'm assuming your front 2 speakers are 4 ohms. According to your manual your amp is stable down to 2 ohm bridged. If you bridge the 2 front speakers (run in parallel using Left Front + and Right Front -) you'll produce a 2 ohm load, giving you apx. 100 watts per front speaker. I would suggest keeping them the way they are now though (1 speaker per front channel). I hate bridging when you don't have to. As long as your 8" sub is 4 ohms, then hook it up to the Left Rear + and Right Rear -. That will give you your 200rms Bridged to the rear channels. Bridging Squirrel

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Yes, max power will be at 2 ohms for the front, because bridging is only good for subs (who wants a mono car?). So you'll probably have to put 2 4-ohm speakers in parallel if you really want that 100W. Only subs tend to come in 2-ohm versions (well usually 4-ohm DVC to make 2-ohm). 2009 Pontiac G8 in planning stage

HU: ?

Speakers: ?

Amps: ?

wvsquirrel wrote: If you bridge the 2 front speakers (run in parallel using Left Front + and Right Front -) you'll produce a 2 ohm load, giving you apx. 100 watts per front speaker. I would suggest keeping them the way they are now though (1 speaker per front channel). I hate bridging when you don't have to. Bridging

What I'm trying to achieve vwsquirrel is more watts for my front stage, cause I'm not really happy with how loud it is now, but I also don't want to lose SQ so what is my best option here. Thanks again bro. I got these specs of www.epinions.com: Frequency Response 58Hz-20kHz Impedance Rating 4 ohms Manufacturer Part Number RC51 Peak Power 100 Watts Recommended RMS Power Range 200 Sensitivity 93 dB

I think you got your specs reversed... usually Peak Power is more watts than RMS (I think it should be 100 watts rms and 200 watts peak) Keeping them in just parallel (1 speaker per channel, not bridged) will give you apx. 50 watts per front speaker), but will save SQ. If you bridge the front speakers and run them in parallel you should get apx. 100 watts per front speaker. You don't have to re-wire them inside the car to get the parallel configuration (meaning you don't have to rerun wires throughout the car), just hook the + of each up to the Left Front +, and the - of each to the Right Front -. Be aware that if you do this, you will sacrifice SQ and you will only get a MONO signal. Your front left/right signals will be the same (not stereo anymore). This is why bridging is usually only done for subs. If you're not happy with the sound (not loud enough) and want to keep SQ, I'd suggest getting a more powerful amp to run them that wouldn't require bridging and would allow you to continue in Stereo, not MonoSquirrel

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So how could I see a 2ohm stereo load(100X4) using my setup? I'm still unclear about this Squirrel, I just copied+pasted the info as it was on the site, but I noticed that also. I just bouth this amp so I'm not to anxious to sell it...although for the right price I might Dragonrage said: "So you'll probably have to put 2 4-ohm speakers in parallel if you really want that 100W." What would be the results if I did this? I'm just trying to get the most out of this amp and work w/ what I have right now w/o sacrificing SQ, although I know I'm prob. sounding like a dumbass.

I know you're probably getting confused, so I'll type slowly Just kidding! No one is a dumbass here. The only stupid question is the one that never got asked. I'm not a professional installer, but here goes anyway. Hope you're sitting down 'cause this is gonna be a long one! First, here's an example of running two 4 ohm speakers in parallel to get a 2 ohm load (courtesy of Rockford Fosgate) (the diagram shows SVC subs, but the principle is the same for your speakers) To get the 2 ohm load you either have to OPTION 1 Bridge and wire parallel (meaning all +'s are wired together and all -'s are wired together, + of each up to the Left Front + and the - of each to the Right Front -). But again, you will be in mono OPTION 2 You could wire both speakers to 1 channel (wired in parallel useing only 1 channel [both going to Right Front + and Right Front -, or Left Front + and Left Front -]) for a 2 ohm load. That's not a bridge (since you're only using 1 channel instead of 2) and would have 100w on that 1 channel. But, since you would have 2 speakers on that 1 channel, each speaker would still only get about 50w and you would be in mono again (which defeats trying to keep SQ). So your best bet is to keep each front speaker on it's own channel (retaining stereo and SQ) at 50w per speaker (even though you would still be underpowering your speakers with this amp). OPTION 3 There is another trick you can do but it means sacrificing that 8" sub. Most 4 channel amps have 2 sets of inputs (1 for the front channel and 1 for the rear), which allows the one 4-channel amp to act as two 2-channel amps (which is why you can bridge 2 channels, but don't have to bridge the other 2 as well). Most people automatically think Front and Rear (Front Left/Right AND Rear Left/Right) with 4 channel amps, but you can also make them strictly Left and Right (Front Left/Right OR Rear Left/Right) instead. When you bridge, the signal gets changed to Mono (usually Left channel input). Well... Run the Left Front RCA from the HU (Head Unit) to the Left Front input on the amp, and switch the Front input to Mono. Run the Right Front RCA from the HU to the Left Rear Input on the amp, and switch the Rear input to Mono as well. I know it sounds wierd because of the way the amps are marked, but it really depends on where the signal comes from, not where it ends up. Even though the amp thinks it's receiving a mono Front and Rear signal, it is really receiving a Stereo Front only signal. You can now bridge the Front Left speaker on the amps Front channels (Front Left + and Front Right -) with a 4 ohm load (200w), and the Front Right speaker on the amps Rear channels (Rear Left + and Rear Right -) with a 4 ohm load and 200w. Presto, bridged amp for max output and stereo retained. I've done this before and it works. In fact, I'm getting ready to rewire my car this way, and add a second 4 channel amp that I already have to do the same thing with my rear speakers. WARNING If you do what I just described, then you will be running your component speakers at their PEAK level of 200w per speaker and run a serious risk of blowing them. You will also not have the use of the 8" sub and would require another amp for that. OPTION 4 You would have another option available if you were to buy another 8" sub (making it 2-8" 4 ohm subs total). According to your manual, your amp is stable at 2 ohms bridged. So, using the wiring configuration that I just described above (OPTION 3), also wire the 8" subs in parallel with the front speakers (meaning the front bridged amp channel will have the Front Left speaker and an 8" midbass sub for a total of 2 ohms, and the rear bridged amp channel will have the Front Right speaker and an 8" midbass sub for a total of 2 ohms). Your manual doesn't give the exact output specs for running 2 channels bridged @ 2 ohms, but I can tell you that each of your 2 normal speakers should receive at least 100 watts each, and each 8" sub should receive at least 100 watts as well. Lower ohms=less resistance=more power output(watts), which is why I said you would get at least that amount, and actually should get more than 100 watts per speaker/sub. I think this is the closest you will come to reaching what you're trying to do with the equipement you've got (plus the additional 4 ohm 8" sub). I would not suggest trying this option with only 1-8" sub because your power balance to the 2 front speakers will be different, which will throw the stereo effect off balance (1 side will be louder than the other) If you decide to get a different amp, I suggest either a 2 channel amp pushing 100w x 2 @ 4 ohms for the front speakers and another for the 8" (which you never gave specs for), or a different 4 channel amp that pushes 100w x 4 @ 4 ohms (instead of 2 ohms). If your amp is as new as you say, I'd exchange it. I hope this helps. Please let me know if I confused you Squirrel

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Well, vwsquirrel, what can I say...you have been a tremendous amount of help Wish there was more people as helpful as you! Option #4 is just about perfect. All i need now is to find a pair of 4ohm midbass drivers. Can you name some good ones? If I do #3 is there any why I can do that and protect my speaker from getting blown, until I do obtain the mids?

You're welcome, glad to help. I have to give props to the rest of the Forum though, without them I wouldn't have the knowledge that I have. Unfortunately I don't know much about 8" midbass drivers. Velocity mentioned a few in your other post, and also said the ones you mentioned were a good place to start as well. Judging by your amps manual ( Tantrum 400.4) you can do several things to help save your speakers until you get the 8" subs... 1) Turn down your Input Sensitivity (gains) on the front and rear channels of the amp. It's labeled as Sens and you have 1 for the front and 1 for the rear. Make sure you turn them both to the same thing! Otherwise you'll get a power difference and the stereo effect will be out of balance. And since you'll be using the amp for Front Left and Right (instead of Front and Rear) balance becomes very impoutant! It's wierd, because to turn it down, you have to turn it to a higher number (Higher Number=Lower Sensitivity). Turn it Counter-Clockwise to decrease the sensitivity (turn it towards the 4, not the .2) You can turn it back up to match you HU's output once you get the 8" subs. 2) Your amp has an 18db booster on it (called Twin-T Bass Eq) and it's labeled as Bass on your amp (right beside your Sens (sensitivity) adjustments). Turn this to 0. Again, you have 2 of these, 1 for the front and 1 for the rear. Without the 8's, you don't need that extra 18db to your front speakers. Let us know if there's anything else you need help withSquirrel

"No more Cpt. Kirk chit chat"

If its too loud, then you're too old

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