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Old 07-23-2010, 03:16 PM   #1
JimShaw JimShaw is offline
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Default Is there any sound quality difference between using 4Ohms vs 8Ohms?

Is there any sound quality difference between using 4Ohms vs 8Ohms on the same speakers?

What I mean is this: If I have speakers that have a switch that can be changed from 4 to 8Ohms and a receiver that has no problem pushing either, is there a difference in sound quality between the two settings?

My thinking is this:
If I played a movie using 8Ohms speakers then switched the speakers over to 4Ohms and played the same move, the only difference in sound between the two would be that I have to turn the volume down on the 4Ohms to match what was heard by using 8Ohms, correct? The quality is the same for both?
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Old 07-23-2010, 03:38 PM   #2
Johnny Vinyl Johnny Vinyl is offline
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Quote:
Originally Posted by JimShaw View Post
Is there any sound quality difference between using 4Ohms vs 8Ohms on the same speakers?

What I mean is this: If I have speakers that have a switch that can be changed from 4 to 8Ohms and a receiver that has no problem pushing either, is there a difference in sound quality between the two settings?

My thinking is this:
If I played a movie using 8Ohms speakers then switched the speakers over to 4Ohms and played the same move, the only difference in sound between the two would be that I have to turn the volume down on the 4Ohms to match what was heard by using 8Ohms, correct? The quality is the same for both?
What you're describing is a game I wouldn't want to play. Whether movies or music, I would NEVER entertain the thought of switching speaker impedance. First, there is ZERO benefit to be gained and second, you can do some serious damage to your speakers or components if not timed properly.

Play your speakers at their recommended impedance and don't change it.

John
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Old 07-23-2010, 03:51 PM   #3
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Quote:
Originally Posted by JimShaw View Post
Is there any sound quality difference between using 4Ohms vs 8Ohms on the same speakers?

What I mean is this: If I have speakers that have a switch that can be changed from 4 to 8Ohms and a receiver that has no problem pushing either, is there a difference in sound quality between the two settings?

My thinking is this:
If I played a movie using 8Ohms speakers then switched the speakers over to 4Ohms and played the same move, the only difference in sound between the two would be that I have to turn the volume down on the 4Ohms to match what was heard by using 8Ohms, correct? The quality is the same for both?
If, as you say, the receiver can handle 4 ohms, then there would be no need to worry about potential damage.

You're right that they would play louder in the 4 ohm position. The lower impedance does cut the damping factor in half, and whatever losses are attributable to the speaker wire itself are also doubled.

One other potential benefit to using the 8 ohm setting is that any amplifier noise will be reduced by the same factor as the loudness difference.

These are all miniscule factors, but that's where we are.

It would help to know what speaker you are using. There might be some other effects to consider based on the method being used to change the impedance.

Last edited by srrndhound; 07-23-2010 at 03:54 PM.
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Old 07-23-2010, 03:56 PM   #4
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The ohms are a measure of resistance or load that is presented to the power source (amp, avr, etc.)
Some amps are stable at 4 ohms because they are built to be able to operate at that load. Some amps are not stable and then the problems start. If the amp is not designed to work at 4 ohm loads then you will likely suffer: excessive heating of amp, distorted or poor sound quality, possible amp failure that could lead to speaker damage. Follow the guidelines in your owners manual for your amp. If it says stable at 2 ohms, 4 ohms, 6 ohms, 8 ohms or whatever, DO NOT use a speaker that is not compatible, follow the instructions.

Also, almost all speakers load ratings change during use. I can't remember if electrostatics change bu they likely do not. The rating you see on your speaker is an average or a minimum load that will be presented to the amp. Temporary fluctuations during listening should not be sweated. This does not negate the fact that you should not run 4 ohm speakers with an amp rated at 8 ohms only.

The volume increase you mentioned is normal. You could think of the amp power like a garden hose. Water flows at high volume but low pressure if there is no nozzle (8 ohm) where as if you cover the end of the hose 50% (4 ohm) then you end up with reduced volume of water but much higher pressure. The pressure is what makes the speaker move = watts. Good amps can sometimes double their watts if the ohms change from 4 to 8. The mfg. will let you know this in your manual.

rock on
mark

I have the same receiver 7002. I think it is only stable down to 6 ohms. There is a sticker on the back. The amp does allow you to combine 4 channels to 2 to double the power. Refer to manual on how to do this.

Last edited by airkitty; 07-23-2010 at 03:59 PM. Reason: update
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Old 07-23-2010, 06:24 PM   #5
JimShaw JimShaw is offline
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Quote:
Originally Posted by John72953 View Post
What you're describing is a game I wouldn't want to play. Whether movies or music, I would NEVER entertain the thought of switching speaker impedance. First, there is ZERO benefit to be gained and second, you can do some serious damage to your speakers or components if not timed properly.

Play your speakers at their recommended impedance and don't change it.

John
Why is it a game?

I can run 4,6 or 8Ohms through my speakers and any setting is recommended by its manufacturer.

I don't think you understand my question.

My question was: is there any differences in sound QUALITY between 4 vs 8Ohms
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Last edited by JimShaw; 07-23-2010 at 06:33 PM.
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Old 07-23-2010, 06:26 PM   #6
JimShaw JimShaw is offline
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Originally Posted by srrndhound View Post
If, as you say, the receiver can handle 4 ohms, then there would be no need to worry about potential damage.

You're right that they would play louder in the 4 ohm position. The lower impedance does cut the damping factor in half, and whatever losses are attributable to the speaker wire itself are also doubled.

One other potential benefit to using the 8 ohm setting is that any amplifier noise will be reduced by the same factor as the loudness difference.

These are all miniscule factors, but that's where we are.

It would help to know what speaker you are using. There might be some other effects to consider based on the method being used to change the impedance.
SpeakerCraft AIM8 Fives have a switch that can change impedance from 4, 6 or 8Ohms
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Old 07-23-2010, 06:31 PM   #7
JimShaw JimShaw is offline
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Quote:
Originally Posted by airkitty View Post
The ohms are a measure of resistance or load that is presented to the power source (amp, avr, etc.)
Some amps are stable at 4 ohms because they are built to be able to operate at that load. Some amps are not stable and then the problems start. If the amp is not designed to work at 4 ohm loads then you will likely suffer: excessive heating of amp, distorted or poor sound quality, possible amp failure that could lead to speaker damage. Follow the guidelines in your owners manual for your amp. If it says stable at 2 ohms, 4 ohms, 6 ohms, 8 ohms or whatever, DO NOT use a speaker that is not compatible, follow the instructions.

Also, almost all speakers load ratings change during use. I can't remember if electrostatics change bu they likely do not. The rating you see on your speaker is an average or a minimum load that will be presented to the amp. Temporary fluctuations during listening should not be sweated. This does not negate the fact that you should not run 4 ohm speakers with an amp rated at 8 ohms only.

The volume increase you mentioned is normal. You could think of the amp power like a garden hose. Water flows at high volume but low pressure if there is no nozzle (8 ohm) where as if you cover the end of the hose 50% (4 ohm) then you end up with reduced volume of water but much higher pressure. The pressure is what makes the speaker move = watts. Good amps can sometimes double their watts if the ohms change from 4 to 8. The mfg. will let you know this in your manual.

rock on
mark

I have the same receiver 7002. I think it is only stable down to 6 ohms. There is a sticker on the back. The amp does allow you to combine 4 channels to 2 to double the power. Refer to manual on how to do this.
Mark

Marantz has told me the SR7002 is stable at 3.2Ohms. This is the requirements for THX certification which the SR7002 is.
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Old 07-23-2010, 08:13 PM   #8
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I am gong to have to say no to thisÖ It may perceive to be better quality because itís louder. Some people argue that about the lossless TrueHD, DTS Master and PCM. They are hearing a louder version of the other codec and think itís better, when itís the same lossless soundtrack.

But the question should go back to you, since you yourself, said that you had to turn it down. What you were doing was turning it down to about the same SPL.

When you turned it down to come close to the same SPL with the 4 or 8, did one sound better over the other?
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Old 07-23-2010, 09:38 PM   #9
JimShaw JimShaw is offline
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Originally Posted by HAMP View Post
I am gong to have to say no to thisÖ It may perceive to be better quality because itís louder. Some people argue that about the lossless TrueHD, DTS Master and PCM. They are hearing a louder version of the other codec and think itís better, when itís the same lossless soundtrack.

But the question should go back to you, since you yourself, said that you had to turn it down. What you were doing was turning it down to about the same SPL.

When you turned it down to come close to the same SPL with the 4 or 8, did one sound better over the other?
I was talking a hypothetical. I haven't tested anything at this time.

What I said was...

If I played a movie using 8Ohms speakers then switched the speakers over to 4Ohms and played the same move, the only difference in sound between the two would be that I have to turn the volume down on the 4Ohms to match what was heard by using 8Ohms? The quality is the same for both?

It seems to me that the only difference between the two would be that you would have to turn the volume down on the 4Ohms to reach the sale sound level but the quality would be the same.
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Old 07-23-2010, 10:26 PM   #10
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Hi Jim,
There could and would likely be a detrimental sound quality change going from 8 to 4 ohms. Here's why for example: a passive sub rated to handle 220 watts at 8 ohms and your receiver producing 110 watts at 8 ohms. You take and swith the sub to 4 ohms and the receiver responds by doubling it's output watts to 220. This appears like a likely good thing but consider this. You have not changed the current available to the subs only the watts. The current is what is actually controlling the subs motion so you are stressing the amp (see previous post) and increasing the volume but you are going backwards on speaker control because the amp is stressed. Now in this example I use a sub because the impedence or ohms of the sub can really drop at low frequencies and high volumes. So you are chilling watching a good blu ray at a pleasant volume when a nice deep impact happens on the movie. What happens? Your amp might cough or clip or how ever you want to describe it but the essence is this when you really want everything to work it's best it will be more likely to fail. Fail in the sense that some control of the sub will be lost.
Thanks for letting me know the specs on the 7002. I was at the office and did not have the manual in front of me.
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Old 07-23-2010, 10:30 PM   #11
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Quote:
Originally Posted by JimShaw View Post
I was talking a hypothetical. I haven't tested anything at this time.

What I said was...

If I played a movie using 8Ohms speakers then switched the speakers over to 4Ohms and played the same move, the only difference in sound between the two would be that I have to turn the volume down on the 4Ohms to match what was heard by using 8Ohms? The quality is the same for both?

It seems to me that the only difference between the two would be that you would have to turn the volume down on the 4Ohms to reach the sale sound level but the quality would be the same.
The reason I asked what speaker you had in mind turns out to be important. The Aim8 speakers have switches that let you tailor the tone quality, and these settings affect the impedance:

>>Frequency Settings
When selected, the settings will have the following result:
-3dB: Reduces the loudness of the selected frequency (bass & treble)
0dB: The selected frequency (bass & treble) remains at neutral level
+3dB: Increases the loudness of the selected frequency (bass & treble)

When adjusting the bass frequency, the impedance will be affected as indicated below. Be sure to stay within the impedance guidelines of the amplifier you will be using to power your system.
-3dB: The impedance is 8 ohm
0dB: The impedance is 6 ohm
+3dB: The impedance is 4 ohm <<

So the answer is an emphatic yes--changing the the impedance will make a big difference in sound quality. But not because of the ohms ratings--that is just a byproduct of changing the tone settings.
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Old 07-23-2010, 10:34 PM   #12
JimShaw JimShaw is offline
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Quote:
Originally Posted by srrndhound View Post
The reason I asked what speaker you had in mind turns out to be important. The Aim8 speakers have switches that let you tailor the tone quality, and these settings affect the impedance:

>>Frequency Settings
When selected, the settings will have the following result:
-3dB: Reduces the loudness of the selected frequency (bass & treble)
0dB: The selected frequency (bass & treble) remains at neutral level
+3dB: Increases the loudness of the selected frequency (bass & treble)

When adjusting the bass frequency, the impedance will be affected as indicated below. Be sure to stay within the impedance guidelines of the amplifier you will be using to power your system.
-3dB: The impedance is 8 ohm
0dB: The impedance is 6 ohm
+3dB: The impedance is 4 ohm <<

So the answer is an emphatic yes--changing the the impedance will make a big difference in sound quality. But not because of the ohms ratings--that is just a byproduct of changing the tone settings.
Yes, the treble does change when switching BUT the bass doesn't. The bass switch changes the Ohms settings. it doesn't really do anything to bass.
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Last edited by JimShaw; 07-24-2010 at 01:22 AM.
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Old 07-24-2010, 01:07 AM   #13
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Quote:
Originally Posted by JimShaw View Post
Yes, the treble does change when switching BUT the bass doesn't. The bass switches changes the Ohms settings. it doesn't really do anything to bass.
I'm just reporting what the manual says. I believe they say bass because it adjusts the loudness of the woofer relative to the tweeter, and that covers everything up to wherever the tweeter kicks in, maybe 2 kHz? It's not like a normal bass control.

As you can deduce, the woofer is 4 ohm, and the switches each add 2 ohms to reduce the loudness of the woofer by 3 and 6 dB.

Last edited by srrndhound; 07-24-2010 at 01:10 AM.
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Old 07-24-2010, 01:24 AM   #14
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Quote:
Originally Posted by srrndhound View Post
I'm just reporting what the manual says. I believe they say bass because it adjusts the loudness of the woofer relative to the tweeter, and that covers everything up to wherever the tweeter kicks in, maybe 2 kHz? It's not like a normal bass control.

As you can deduce, the woofer is 4 ohm, and the switches each add 2 ohms to reduce the loudness of the woofer by 3 and 6 dB.
I have 6 AIM8 Fives in my ceiling right now and all the bass switch does is change the Oms setting
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Old 07-24-2010, 03:46 AM   #15
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Quote:
Originally Posted by JimShaw View Post
I have 6 AIM8 Fives in my ceiling right now and all the bass switch does is change the Oms setting
I've already explained what the woofer switch does in some detail based on the manufacturer's information. Is there some confusion? If you think it does something different, I'd recommend taking that up with the manufacturer.
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Old 07-27-2010, 12:01 AM   #16
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Quote:
Originally Posted by JimShaw View Post
I have 6 AIM8 Fives in my ceiling right now and all the bass switch does is change the Oms setting
As stated earlier, the adjustment your referring to is designed to change the bass output of the speaker. It is stated on page 5 of the following manual:

http://www.onidserv.com/resources/sp..._manual_en.pdf

However, if you use a receiver and have your speakers set to "small," then your speakers are probably not receiving any audio information below 80 Hz, or whatever your low frequency cut-off is. So, in other words, changing the settings will not do what the manufacturer intended, which is fine. I would recommend leaving the speakers in the 6 ohm position, since that is considered the normal +/- 0 setting.
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Old 07-27-2010, 12:10 AM   #17
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Quote:
Originally Posted by kingofgrills View Post
As stated earlier, the adjustment your referring to is designed to change the bass output of the speaker. It is stated on page 5 of the following manual:

http://www.onidserv.com/resources/sp..._manual_en.pdf

However, if you use a receiver and have your speakers set to "small," then your speakers are probably not receiving any audio information below 80 Hz, or whatever your low frequency cut-off is. So, in other words, changing the settings will not do what the manufacturer intended, which is fine. I would recommend leaving the speakers in the 6 ohm position, since that is considered the normal +/- 0 setting.
I talked to SpeakerCraft techs today and was told the Bass switch does two things. Changes the speakers to 4. 6 or 8Ohms depending on setting. PLUS it also changes how much bass comes from that speaker. I was also told that the switching to: +3, more bass/4Ohms does not effect the bass going to the power sub at all but does give a little more bass from the speaker.
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Last edited by JimShaw; 07-27-2010 at 12:13 AM.
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Old 07-27-2010, 06:37 AM   #18
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Impedance of a loudspeaker is not a measure of sound quality. Same for Sensitivity.

* What is though is the design, the implementation of the various drivers, their compatibility with each other, the x-overs, the box integrity, the totality of the parts (smooth phase angle, power room response, frequency response on and off axis, smooth impedance curve without too high variations, waterfall response, etc.).

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