Ohms affect performance?

[Pony]

I just got done building this box for my subwoofers.<br /><br /> <br /><br /> <br /><br /> <br /><br /><br />Right now I have them wired in an 8ohm set-up....any advantage/ disadvantage to rewiring this box with a 4ohm set-up?

 

[Bob_VT]

Re: Ohms affect performance?

It depends on what is driving them. Most stock auto speakers in dash are 4 ohm and most home stereo and aftermarket are 8 ohm.

 

[JB]

Re: Ohms affect performance?

Performance will suffer unless the impedance of the load (speakers) matches the impedance of the source (amp.).<br /><br />Check you amp for output impedance. It is probably 8ohm if it is an aftermarket or premium, 4 ohm if it is an OEM radio. It should be labeled on the amp.

 

[ehenry]

Re: Ohms affect performance?

P.O.N.Y. i had a sub box i would have given you! ! ! Looks just like that one.

 

[Pony]

Re: Ohms affect performance?

Heres the cd player :<br /> http://www.pioneerelectronics.com/pna/product/detail/0,,2076_4039_49927926,00.html <br /><br /><br />I will look at the amp today and see whats written on there. <br /><br /><br />I think my favorite part of the box was actually building it.......used metal flake paint, but it doesnt picture too well.

 

[tommays]

Re: Ohms affect performance?

http://www.crutchfieldadvisor.com/learningcenter/car/amplifiers_faq.html#13 <br /><br />They have a lot of good free advise here that covers all the ways you might do it<br /><br /><br />

<br /><br /><br />tommays

 

[vipzach]

Re: Ohms affect performance?

What amp do you have pony? What ohm spekers are in the box? <br />You need to know what ohm load your amp will handle, before you decide which way to wire it up.<br /><br />edit: The short answer to your question is "yes", ohm's will affect performance. Look at this web site also, I used to install audio/video systems in cars for a living and used it alot when I first started. Car stereo basics

 

[rattana]

Re: Ohms affect performance?

Yes like JB says, you need to match speakers to the amp. If not performance will suffer. Here is another good site for car audio<br /> http://www.bcae1.com/

 

[18rabbit]

Re: Ohms affect performance?

Pony, you can think of ohms as the resistance the audio signal needs to overcome to get from + to -. And you can think of the amp as needing some resistance to prevent it from shorting out. With that in mind, if you use an amp rated for 4ohms to drive spkrs rated at 8ohms, the amp is working harder (twice the watts) to overcome the extra resistance to make the music. Not necessarily an issue if your amp has enough reserve watts (umph) to bring the spkrs up to the volume that you want. Most often what happens is you get less volume than desired at full output, presuming you get enough umph to get past the spkr’s threshold.<br /><br />Going the other way, using am amp rated at 8ohms and spkrs rated at 4ohms means there isn’t as much resistance as the amps wants to keep it from running away. Yup, you get more sound, but that amp is heating up, possibly to the point of melting down.<br /><br />In general, as long as you are adding higher resistance along the path, you won’t damage the equipment, just get less volume. If you reduce the resistance anywhere along the path, you have the potential for things to burn up/blow out. <br /><br />Most quality amps will work to 4ohms min, some to 2ohms, and a few high end amps work at 1ohm. The amp’s specs will tell you how many watts of power the amp is capable of when driving sprks of 2, 4, 6, and/or 8 ohms. Subwoofer spkrs tend to be at the higher end of resistance, 8 ohm systems.

 

[Pony]

Re: Ohms affect performance?

Rabbit, thanks for that explanation.....that pretty much goes along the lines of what i was thinking.<br /><br />The subs are 8ohm capacity. I found a manual online for the model number and verified my series set-up is an 8ohm circuit. have had them wired that way for a year in their old "box" Sounds good <br /><br />The amp is a crunch 300series...its old. , but can handle the ohms im using.<br /><br />thanks for the links everyone

 

[--GQ--]

Re: Ohms affect performance?

Ohms will not affect performance, however speakers with 8 ohms will not handle too much bass since the coil is of a smaller guage wire as suppose to 2 ohms speakers which are designed for higher bass output. Connecting 2 ohms speakers to 8 ohms rated amplifiers will more than likely damage your amp. If bass is what ur after, a 2 ohms set-up is the way to go.

 

[vipzach]

Re: Ohms affect performance?

Originally posted by --GQ--:<br /> Ohms will not affect performance, however speakers with 8 ohms will not handle too much bass since the coil is of a smaller guage wire as suppose to 2 ohms speakers which are designed for higher bass output. Connecting 2 ohms speakers to 8 ohms rated amplifiers will more than likely damage your amp. If bass is what ur after, a 2 ohms set-up is the way to go.

ohms will affect performance. If you have an amp rated at 200 watts with a 4 ohm load or 400 watts at a 2 ohm load, how can you say that ohm's don't affect the performance? Dropping or raising the ohm load affects how much power the amp can put out.<br /><br />"however speakers with 8 ohms will not handle too much bass since the coil is of a smaller guage wire as suppose to 2 ohms speakers which are designed for higher bass output."<br /><br />That is not a very accurate statement. Just because it is rated at 8 ohm's doesn't mean it can't handle much bass. How much it can handle is detemined by its continues power rating, not its ohm rating. The ohm ratings are for when you are adding multuple subs to one amp. For example: You have an amp that can handle a two ohm load and you already have two 8 ohm subs and want to add more, without blowing the amp. You would hook them up parallel and have a two ohm load with lots of bass, using your 8 ohm speakers. Another example: You have an amp that is only rated to run at 8 ohms and have two subs, both are rated at 4 ohms each. You would hook them in series and have an 8 ohm load.

 

[--GQ--]

Re: Ohms affect performance?

Hmmmm I must have been on vacation for too long. I can't think straight. To my understanding the question posted by the originator is, "Does ohms affect performance"? That is a vague question. In which way? What type of music do you listen to?....ect...ect...<br /><br />Speakers are rated in watts and measured in Decibel ( DB ). A decibel meter does not distinguish between low mid or high frequency. It measure noise pouring out of your speakers. <br /><br />Low frequency noise "bass" is not as loud per watts but you can hear it much further. High frequency noise on the other hand is louder but doesn't travel as far. While a person can hear the 100 watts of low frequency bass pouring out of your car a block away, he won't be able to hear the high vocal frequency of the same 100 watts. That is the reason why speakers are designed into three catogories; Low Mid High. Mid and High are restricted to 8 ohms speakers where 2 and 4 ohms speakers use the Low. <br /><br />To answer your question, converting your 8 ohms speakers to 4 ohms will not affect your "performance". If anything, it will not blow as easy. Hint the resistance of the speakers is less which means it will handle more bass. Having said that, your amplifier must be 4 ohms stable or it will have a short life.<br /><br />In conclusion, seting up your 8 ohms speakers into 4 ohms will NOT affect the performance. The construction of the speakers determines its performance such as the size of the voice coil, the type of materials used paper/plastic, the depth of the cone...ect...ect...

 

[waterone1@aol.com]

Re: Ohms affect performance?

PONY, there is some good advice above and some total crap. Unless these are dual voice coil speakers (two coils for each spaker) To answer your initial question: it is NOT POSSIBLE to simply rewire two speakers to either be 4 ohms or 8 ohms. That is not a mathmatical possibility. For instance, if each of your two woofers is 4 ohms, then you can wire them in series which will give you 8 ohms. If you take the same two 4 ohm woofers and wire them in parallel then they will become a 2 ohm load. <br />On the other hand, if each of your woofers are rated at 8 ohms, then the choice is either series (16 ohms) or parallel (4 ohms).<br />With all of that said, since this is 2006, we'll forget all about loads of 8 ohms or higher.....that was old technology. Any amp today should be able to handle a load of 4 ohms or less. In most cases an amp will produce more current and keep the voltage fairly constant as the load impedance goes down. Read your amps power ratings at various loads, and watch what it say's for the minimum rated output impedance. I work in the pro audio world, so I am conservative as to the minimum rated impedance......I won't set up a system to run at that.....I'll sacrifice a few DB's for lower amp temps and greater reliability.<br />There is something that is often overlooked when most people talk about car audio, that is dampening factor. Anytime you have a speaker that moves, it produces back EMF (electromotive force), the amps ability to control the back EMF of a speaker is the dampening factor. The bigger your subwoofers and the lower the impedance, the lower the dampening factor goes. If you like rap music....don't even worry about this.....it won't matter. If, on the other hand, you want your system to reproduce a kick drum, to actually sound and feel like one, keep your load impedance above the minimum rated impedance of the amp. <br /><br />On a final note, all of the above discussions are strictly dealing with the ELECTRICAL impedance of speakers. If you use an impedance meter and "sweep" the ACTUAL impedance of a speaker in a given box you will find that it is not anywhere close to flat for a given frequency range. For example, a single 4 ohm sub in a ported box, may have a minimum of 2 ohms at some frequencies and as much as 10 ohms at other frequencies (depending on the thiele-small parameters of the speakers) and the "tuning" of the box. That is just one reason why two very similar speakers/cabinets can sound totally different. There is a-lot of real science to seperate a good system from a great one.

 

[vipzach]

Re: Ohms affect performance?

Thankyou waterone 1, I was hoping some else that does this or used to do this for a living would come along.<br /><br />I hope that my post did not make it sound like a simple wire change would change the ohm rating of a given speaker.If any of my advice is crap, then please point it out to me. <br /><br />In a VERY GENERAL way, the ohm's do affect the performance and I was just trying to explain to PONY that there might be ways to get more sound from his speakers and amp if he told us what his amp and speaker were capable of handling. I would guess that his amp could handle a four ohm load and if he wants more sound he could run them parallel instead of series, since right now he thinks he has it wired in series, which is 16 ohm's.

 

[waterone1@aol.com]

Re: Ohms affect performance?

Vipzach, no, my "crap detector" didn't go off on your post ...LOL.

 

[--GQ--]

Re: Ohms affect performance?

Originally posted by waterone1:<br />[QB] PONY, To answer your initial question: it is NOT POSSIBLE to simply rewire two speakers to either be 4 ohms or 8 ohms. That is not a mathmatical possibility. For instance, if each of your two woofers is 4 ohms, then you can wire them in series which will give you 8 ohms. If you take the same two 4 ohm woofers and wire them in parallel then they will become a 2 ohm load. <br /><br /><br />Same subject, third round. I'm confused. The statements above seem to contradict each other. It is a boy or is it a girl? Is it red or is it blue? Can you or can you not? I disagree 101%. Imagine two coils of wire each has a resistance of 8 ohms. Connect them in parallel. The combined resistance is 4 ohms. Now imagine the two coils inside two speakers. What you have here is two 8 ohms speakers connecdted in parallel to achieve 4 ohms. To say that it is not possible is not true. Connecting them in parallel however will not affect the speakers performance. "Peak" power handling capability will increase but the "Root Mean Square" value remains the same. Speakers are designed to produce certain frequency; low mid high. You can paint it, sand it, slice it, dice it, place it in parellel or series, tweeters will still produce high frequency noise at the same level it was rated. likewise sup-woofers will still pour out low frequency noise. Accoustic characteristics of a box or EMF has nothing to do with wether paralleling two speakers affect performance. They're just pyhsical characteristic of air movement in a confined enclosure and basic electrical principle.<br /><br />Allow me to brag a little. I don't know too much about anything but electricity is my domain. I don't work for any "Sound Shop" nor do i want to; it doesn't pay me nearly enough. However i've been playing with car audio since i was 16. Since Alpine was sporting the 6 green buttons. Since Vidal was with Sassoon. I am now 32 and yes it is my hobby.

 

[waterone1@aol.com]

Re: Ohms affect performance?

GQ, read my statement again, then consider ohms law. If you start with two 8 ohm resistors(in this case speakers), you have a choice: wire them in series and you get 16 ohms. Connect the same two 8 ohm resistors in parralel and you get 4 ohms.<br />Do the same thing with two 4 ohm resistors (or speakers) your choice is either 8 ohms or 2 ohms.<br /><br />So my statement is true, without changing resistors (speakers) it is not possible, simply by changing the wiring to get 8 or 4 ohms from the same speakers (resistors).<br /><br />As far as sound output goes, the two speakers, in the same box, connected together present a single load to the amplifier. Amplifiers are voltage and current devices. Modern amps are able to (for the most part) produce the same voltage while doubling their current output as the load impedance halves (down to their rated minimum load impedance). Soo........ all of that say's that if the speakers are wired in parralel, they will draw more current from the amp and will produce more sound. Wire those speakers in series and the amp is not going to produce as wany watts (E x I) of output power.<br /><br />The original question on this thread was whether he should rewire his 8 ohm box for 4 ohms. I have pointed out (more than once) that unless he changes speakers, it is not possible. If his two speakers that are in series are resulting in 8 ohms (he must have 4 ohm speakers) then changing the wiring will result in 2 ohms.<br />My other "ramblings" were ment to point out that there is more to sound than just "watts". When it comes to larger cones reproducing bass, other factors (such as dampening factor of amp/load) will impact the "sound".<br /><br />GQ, you didn't say what you did in the electrical field, but it sounds like you are happy. I'm 41, I have a degree in electrical engineering, I have worked in the Pro sound field for over 20 years and have owned my own company since 1992. I have travelled all over the world and am able to have play toys such as my 40 foot boat(that is paid for)so I guess I will say that I'm also happy with what I do.

 

[BoatBuoy]

Re: Ohms affect performance?

And if it's a tube amp, we have to start all over again.

 

[waterone1@aol.com]

Re: Ohms affect performance?

LOL....yep, that would be a whole different game.