Getting the Most Watts to Rear Speakers

Hello, I'm a newbie to ohms and watts and series/parallel wiring, and am wondering how to get the most watts to my rear speakers. Parts 5-channel amp At 4 Ohms, 75W x 4, 250W sub At 2 Ohms, 100W x 4, 350W sub Bridged, 4 Ohms 200W x 2, 2 Ohms 350W sub Speakers RMS Power: 250W MAX Power: 500W Frequency Response: 106-17KHz Impedance: 4 ohm 1. If I run the speakers to the amp, each speaker gets 75W. 2. If I run the speakers in parallel, they will be 2 Ohm. Running one set of wires to the amp gets 100W at 2 Ohms, but the power is split evenly to the speakers, so each speaker gets 50W. This is not a worthwhile move. Here's my quandary, bridged, the amp produces 200W at 4 Ohms. How can I know the bridged wattage of 2 Ohms? Can I run the speakers in parallel to 2 Ohms and plug them to the amp bridged? Would that get me more than 75W per speaker? Thank you --Sandra

Your amplifier is not capable of running 2 ohms bridged. Stereo Separation. Google it before you bridge your high frequency speakers.

you will not hear a difference between 75 and 100 watts. To get the smallest noticeable change (+3db) you have to double the amount of power33 years as a installer now just a retired old guy. Favorite thing to install/topic are remote starts/car alarms. Stop using test lights!!!

Sandragu, PLEASE READ THIS... Personally, I wouldn't even WORRY about adding more power to your speakers with frequency response like you have! That's more like mid-range speakers. I never buy or install ANY rear speakers with frequency response higher than about 25Hz to 35Hz in lows. I use subs, but still like a little bit of lows from my rear speakers. I didn't even know they made rear speakers with F/R that high in the low side! If you concentrate LESS on WATTS and MORE on SENSITIVITY and FREQUENCY RESPONSE, you will find you don't NEED more power to make the speakers come to life! Let me explain a bit more... I'm 62 years old, and have been messing with car stereos since I was like 17. Anyway, one thing I've learned through research, experience, and my MECP Study Guide is that watts are NOT the most important spec to look for in a speaker, especially if you have horrible sensitivity ratings and even worse frequency response specs on your speakers. TRUST ME HERE, you started your post by saying you're a newbie to ohms and watts, so please believe what I'm telling you since I've installed car audio in every car I've ever owned since the 70's as well as for many friends and family members. I do a LOT of research on whatever it is I'm looking for, and what I find helps me make my final decision on my equipment. ESPECIALLY when it comes to speakers! So, when I search for a new set of speakers for ANY car, I start out by comparing frequency response. I look for speakers that get the lowest lows and highest highs for their size (like 6.5's or 6x9's). Then I look at sensitivity. I make a list of the better specs I find. Sure, I also look at RMS and peak watts, but only after narrowing down my choices based on sensitivity and frequency response! You can have a speaker that claims to take a whopping 250 watts RMS and 800 watts peak, but if their sensitivity is like 80dB or 85dB, you're going to have to really crank your stereo before you start to hear the speakers, and thereby introducing distortion into them. (I'm still wondering what speakers YOU have that handle 250 watts RMS!) As for the parallel thing, if you run your 4 ohm speakers in parallel, you turn it into a 2 ohm load, which essentially doubles the output of the amp to those speakers. You do NOT get half and half to each speaker. If your amp puts out 75 watts RMS per channel and you connect 2 speakers in parallel, the amp will now put out 150 watts RMS. Both speakers will get this power, not split between them. But you’ll need to lower your gain control if you run your speakers in parallel. IF you decide to not upgrade your speakers and still want more power, my suggestion would be to run FOUR speakers with the exact same impedance in series/parallel. That means you’re running all your speakers in parallel AND series at the same time. You will end up with the same 4 ohms that you started with, so your amp is safe and your speakers will smile. I noticed you didn’t mention the brand of amp you have OR the speakers, and THAT will make a difference. And what size are your rear speakers? Apparently not 6x9’s. My final suggestion is to look for some replacement speakers with frequency response in the neighborhood of 30-20,000Hz or better and sensitivity around 89dB or higher, THEN you will find you don’t need more power back there! One last note about speakers hooked to amps: most people are misled into thinking they need speakers that handle mega watts but that they should keep their amp's power output way below their speaker's rating to save their speakers, when in fact it's just the opposite. You want your amp to put out MORE power than your speakers handle, mainly so you don't have to turn things up so high to get the speakers to sound good. If you have to turn up your stereo, which pumps all kinds of watts to speakers that aren't even CLOSE to sounding good, you're wasting power and probably introducing distortion. My front speakers only handle 60 wpc RMS and my rear speakers handle 120 wpc RMS, yet my amp puts out a true 75 wpc RMS at 4 ohms yet I'm running all four in parallel with tweeters so now my amp is pumping out 150 wpc RMS yet my speakers are rated at much less! BUT, everything sounds awesome because I know how to correctly lower my gains, plus I'm running everything in the High Pass mode so they don't distort from bass. But yes, I'm running an amp that puts out way more than I should be putting into my speakers. Now if it was the other way around, where my speakers handled 150 wpc RMS but my amp only put out 60 wpc RMS, I'd have to turn everything way up before my speakers started working at their full potential but would probably introduce distortion. Distortion is what kills speakers, not power.

kenwood_nut, that's a lot of bad/incorrect information you provided. Frequency response is important for the frequency range needed per speaker application. There is no need for a speaker in a midrange/tweeter application to have a low frequency response of 30Hz. High efficiency ratings are often a trade off for lower accuracy and tend to become tiring sooner. If an amplifier is putting out 150 watts into a 2 ohm load as in your example with two 4 ohm speakers wired in parallel, each speaker is getting 75 watts. They do not magically get 150 watts each. Distortion does not blow speakers. Overpowering speakers will blow them. Plain and simple. End of story. https://www.the12volt.com/installbay/forum_posts.asp?tid=74226~wirewise~ Verify all wiring with your meter before making any connections!

wirewise wrote: kenwood_nut, that's a lot of bad/incorrect information you provided. Frequency response is important for the frequency range needed per speaker application. There is no need for a speaker in a midrange/tweeter application to have a low frequency response of 30Hz. High efficiency ratings are often a trade off for lower accuracy and tend to become tiring sooner. If an amplifier is putting out 150 watts into a 2 ohm load as in your example with two 4 ohm speakers wired in parallel, each speaker is getting 75 watts. They do not magically get 150 watts each. Distortion does not blow speakers. Overpowering speakers will blow them. Plain and simple. End of story. https://www.the12volt.com/installbay/forum_posts.asp?tid=74226

To begin with, this is NOT incorrect information! Read your car audio magazines and MECP study guide plus your IASCA competition manual, then research speakers half your life, THEN reconsider your comment. NOTHING was mentioned by the original poster that he had midranges or tweeters! He said he wanted more power to speakers with frequency response of 107Hz and up, which is horrible if they're full range. I've never heard of ANYONE not starting with at least full-range speakers in the back, especially when they claim to be 250wpc RMS. So it was safe for me to assume that his speakers were full-range! Sure, I could have been like YOU and assumed they were midrange or tweeters, but I'm not that stupid. And if you can show me a pair of 250wpc RMS midranges or tweeters I'll buy them! You might want to study up on series and parallel and power output also. Running speakers in parallel don't CUT the power to them. You can chose to disagree with me, but you can also keep your sarcastic comments to yourself instead of trying to make me look stupid. I've been into car audio since Kraco and Spark-O-Matic where the top brands (LOL!) back in the 70's, and after 45 years of researching car audio stuff and installing it, with years and years of subscriptions to several car audio publications, I learned a wee bit more than you're thinking I might know. So while you're going around telling people that if your run speakers in parallel you're cutting the power in HALF to those speakers, you might want to look at your first comment to me and tell yourself that same thing. Until then, why don't YOU offer YOUR expertise to this guy instead of waiting for a 62 year old car audio lover to offer some insight. You seem to know more.

wirewise wrote: Distortion does not blow speakers. Overpowering speakers will blow them. Plain and simple. End of story. https://www.the12volt.com/installbay/forum_posts.asp?tid=74226

THAT right there is the absolute WORST comment I've ever read in my life! You obviously know VERY little about speakers! You might want to ask some experts at Crutchfield, *****, IASCA, Car Stereo Review, or heck, even watch some youtube videos! I can show you IN PRINT from SEVERAL articles I've saved in my files, that it IS in fact DISTORTION that kills speakers and NOT power! I can't believe YOU are a moderator of this group and you don't know the truth about distortion VS power killing speakers. What a joke! Kick me out of this forum if you want, but I'm not going to stick around and argue with someone who obviously knows VERY little about car stereos, or at least speakers. Your comment just makes YOU look like an idiot, not me! I can't even imagine why you would post such a comment. I CAN, however, imagine how many people are laughing their heads off at you right now.

kenwood_nut wrote: ... I can show you IN PRINT from SEVERAL articles I've saved in my files, that it IS in fact DISTORTION that kills speakers and NOT power!...

Again, you're posting incorrect information, even if others may have written or believe the same. Distortion without overpowering a speaker will not blow a speaker. Overpowering a speaker will blow a speaker. Please read the following topic: https://www.the12volt.com/installbay/forum_posts.asp?tid=74226~wirewise~ Verify all wiring with your meter before making any connections!

Okay, I'll admit I may be HALF wrong. Apparently more research has been done over recent years that has shown distortion doesn't actually kill speakers, but too much power does. But distortion is NOT good for them, no matter how much or little power you pump into speakers. My main point here to the original person with a question (which YOU didn't offer any help on) was that he doesn't need more power, he probably needs better speakers. It was clear to me that his amp (which seemed over rated) had adequate power, but I still can't figure out what kind of speakers have low F/R in the 100's yet handle 250 watts RMS. But that's another story. But I don't appreciate "experts" who don't feel a need to offer THEIR opinion to someone asking a simple question, but are quick to post a sarcastic reply when someone else tries to offer some knowledge that they don't agree with. I don't CARE if you agree with what I post, but you certainly don't need to come on here acting like you're the God of all knowledge and try to make other members look stupid. So there, after a quick google search and finding that recent studies show distortion doesn't "kill" speakers (but it certainly isn't GOOD for them), I won't tell people that anymore. But I would sure appreciate if people didn't just troll through the forums looking for stuff they don't agree with in an effort to make other members (probably twice their age or more) look stupid. That's NOT what forums are for! I don't donate money to this site to get ridiculed by moderators! I would think as a moderator you would offer knowledge and help to those asking for it rather than wait for others to assist new members then slam them because you don't agree with what they say. END OF STORY!

kenwood_nut, there was no sarcasm in my original reply and no intent to make you look bad, only to provide correct information. Prior to your original reply, the OP's questions had already been answered. Distortion sent to a speaker is neither good or bad for a speaker. See audio distortion. By the way, I started making a living in this field in the mid seventies. We're about the same age.~wirewise~ Verify all wiring with your meter before making any connections!