okay simple enough one has more electricity or whatever. but what i want to know is sound quality wise. lets say i have an amp 250w rms @ 4ohm, and it also runs at 500w rms @ 2ohm. wouldn't i be better off to buy a sub that is capable of 500w rms @ 2ohm rather than a sub that's 250w rms @ 4ohm? I would guess the 500w sub would pound a lot harder, keeping out brands and model #'s, by looking at the numbers. thanks.
Replies (5)
audeogod on 02/1/2005 21:52:05
It's my understanding that with almost any amp, the distortion factor goes up when you run it at 2 ohms. So, since you asked about SQ, or sound quality, then I'd say go 4 ohms.
I can't say for sure, maybe someone else can, but it would seem that this would be a little less important for bass, than it would be for midrange and treble.
Look at the amplifier's ratings, if numbers is all you want to use. Some will say an output wattage at 4 ohms with a THD(total harmonic distortion) of 0.something. Then it will also say this again for 2 ohm as you have listed above.
If it just tells the wattage output at different ohm loads, but no THD, then it will be hard to determine without hearing it. At least it would be for me. There may be some other way that I don't know about to tell.
Remember, a THD of 0.1 or less is supposed to be beyond the range of human hearing, meaning you wouldn't notice that amount of distortion. I've actually seen Jensen amps that said 0.5 before. That would be a lot! But you said no brand name mentioning, so just close your eyes and don't read this last sentence. Oops, too late. Sorry.
audeogod on 02/1/2005 22:05:16
Well, now I'm not sure if that's 0.1 or 0.01 that's supposed to be inaudible. I think it's 0.1 and I hope someone else will back me up on one or the other.
Reason I was thinking this is that I was trying to remember. That Jensen amp said an output of so many watts at 4 ohms at 5% THD. Now when you make that a decimal, it's 0.05. Maybe that's what it meant and not really 0.5. Been too long. It was years ago.
P0werLifter on 02/1/2005 22:15:03
When wiring subwoofers or other drivers to net a certain ohm load at an amplifier all your doing is changing the resistance to flow. The higher the ohm, the more stable the load, cleaner power, but less overall power is allowed through. The lower the ohmage load, the less stable, but more power is allowed through.
In general Fullrange speakers are 4ohm, and subwoofers have a variety to choose from, most comming being (Dual Voice Coil 2 , 4ohm) and (Single Voice Coil 4 , 8ohm). The reason being subwoofers have different ohm options is so it gives you the ability to wire the subs to match your amplifiers load capabilities to get the most power.
When dealing with sub's, and lowering ohms in general there is more distortion that is allowd through but as long as you have a quality amplifier with good THD ratings and your amplifier is stable at the ohm load your giving it then you wont notice a difference in distortion between 4 to 1ohm load ratings.
Also you talked about buying a sub that is 250rms compared to a sub that handles 500rms. Keep in mind that subwoofers will perform to max potential with less power than the RMS rating. It just depends with what kind of enclosure you have it in etc. Also keep in mind that everytime you double the RMS wattage you only gain +3 dBs. So to answer your question, a 500watt Sub will be 3db Louder compared to a subwoofer that is 250watt Rms, (Note: a +3dB gain at 120dB and above is really inaudiable to the ear)
Just make sure when selecting a subwoofers ohm ratings and power ratings that you consider the wiring options, and the RMS value of the subwoofer and amplifier. NOT the MAX power!!!!
uochronos on 02/2/2005 02:44:46
most human ears cant detect THD distortion below say 5%....
Chronos
musak99 on 02/2/2005 06:01:43
ok thanks guys i understand now. weird how not everyone is using 2ohm...seeing that there's only a bit more distortion but that may not be audible to the ear
thank you
Replies (5)
audeogod on 02/1/2005 21:52:05
It's my understanding that with almost any amp, the distortion factor goes up when you run it at 2 ohms. So, since you asked about SQ, or sound quality, then I'd say go 4 ohms.
I can't say for sure, maybe someone else can, but it would seem that this would be a little less important for bass, than it would be for midrange and treble.
Look at the amplifier's ratings, if numbers is all you want to use. Some will say an output wattage at 4 ohms with a THD(total harmonic distortion) of 0.something. Then it will also say this again for 2 ohm as you have listed above.
If it just tells the wattage output at different ohm loads, but no THD, then it will be hard to determine without hearing it. At least it would be for me. There may be some other way that I don't know about to tell.
Remember, a THD of 0.1 or less is supposed to be beyond the range of human hearing, meaning you wouldn't notice that amount of distortion. I've actually seen Jensen amps that said 0.5 before. That would be a lot! But you said no brand name mentioning, so just close your eyes and don't read this last sentence. Oops, too late. Sorry.
audeogod on 02/1/2005 22:05:16
Well, now I'm not sure if that's 0.1 or 0.01 that's supposed to be inaudible. I think it's 0.1 and I hope someone else will back me up on one or the other.
Reason I was thinking this is that I was trying to remember. That Jensen amp said an output of so many watts at 4 ohms at 5% THD. Now when you make that a decimal, it's 0.05. Maybe that's what it meant and not really 0.5. Been too long. It was years ago.
P0werLifter on 02/1/2005 22:15:03
When wiring subwoofers or other drivers to net a certain ohm load at an amplifier all your doing is changing the resistance to flow. The higher the ohm, the more stable the load, cleaner power, but less overall power is allowed through. The lower the ohmage load, the less stable, but more power is allowed through.
In general Fullrange speakers are 4ohm, and subwoofers have a variety to choose from, most comming being (Dual Voice Coil 2 , 4ohm) and (Single Voice Coil 4 , 8ohm). The reason being subwoofers have different ohm options is so it gives you the ability to wire the subs to match your amplifiers load capabilities to get the most power.
When dealing with sub's, and lowering ohms in general there is more distortion that is allowd through but as long as you have a quality amplifier with good THD ratings and your amplifier is stable at the ohm load your giving it then you wont notice a difference in distortion between 4 to 1ohm load ratings.
Also you talked about buying a sub that is 250rms compared to a sub that handles 500rms. Keep in mind that subwoofers will perform to max potential with less power than the RMS rating. It just depends with what kind of enclosure you have it in etc. Also keep in mind that everytime you double the RMS wattage you only gain +3 dBs. So to answer your question, a 500watt Sub will be 3db Louder compared to a subwoofer that is 250watt Rms, (Note: a +3dB gain at 120dB and above is really inaudiable to the ear)
Just make sure when selecting a subwoofers ohm ratings and power ratings that you consider the wiring options, and the RMS value of the subwoofer and amplifier. NOT the MAX power!!!!
uochronos on 02/2/2005 02:44:46
most human ears cant detect THD distortion below say 5%....
Chronos
musak99 on 02/2/2005 06:01:43
ok thanks guys i understand now. weird how not everyone is using 2ohm...seeing that there's only a bit more distortion but that may not be audible to the ear
thank you
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