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batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS

8Ohm speakers on 6Ohm amp...

Greetings;

I have a nice set of Bose Bookshelf speakers that I'd like to keep using, when I get rid of my vintage 1991 Kenwood receiver. The Surround System I'm thinking of getting has 6Ohm speakers.

Question: Will I destroy the amplifier if I connect 8Ohm speakers to an amp that's expecting a 6Ohm load?

Specifically, I'm considering the Sony HT-DDW790 or maybe the 990.


russotto

join:2000-10-05
West Orange, NJ

Generally a higher impedence speaker results in lower efficiency but not damage to the amp.


batsona
Maryland

join:2004-04-17
Ellicott City, MD

Meaning you have to pump the volume up higher to achieve the equivlant result as you would against a 6-Ohm speaker?



Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2

Yes, it won't be as loud (at the same setting). It will be 25% less efficient.

See if the amp has a switch for setting a different OHM rating. I've seen some with the choice of 4 or 8, but often not 6.


batsona
Maryland

join:2004-04-17
Ellicott City, MD

The Sony seems to be rated at 6-Ohm only. No switch for 4-Ohm or 8-Ohm. Since the Sony has settings to balance the volume between rear, R/L, and center, the lower sound coming from my 8-Ohm speakers won't be an issue, because i can compensate.



dadkins
Can you do Blu?
Premium,MVM
join:2003-09-26
Hercules, CA
kudos:18
reply to batsona

8 OHM on a 6 OHM amp will be less load on the amp - but will yield less volume at same volume setting(as others have stated).

No damage will occur!
--
Think outside the Fox... Opera



Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2
reply to batsona

I mis-read your post(s). I thought the speakers were the odd rating, not the receiver. Since the receiver is one of those all-in-one setups, there's no harm in Sony making the receiver 6-ohm capable. They expect people to use their 6-ohm speakers with it.



HRM
God Bless America
Premium,MVM
join:2002-02-03
Darien, CT
kudos:1

No issue at all as others have mentioned. The only side effect would be more heat, so just make sure (like will all amps) that there is good air circulation.



dadkins
Can you do Blu?
Premium,MVM
join:2003-09-26
Hercules, CA
kudos:18

said by HRM:

No issue at all as others have mentioned. The only side effect would be more heat, so just make sure (like will all amps) that there is good air circulation.
More heat? Less load = less heat.
Higher resistance - less load.
--
Think outside the Fox... Opera


HRM
God Bless America
Premium,MVM
join:2002-02-03
Darien, CT
kudos:1

You have to turn the amp up higher to get the same volume. It will run hotter. It would be the same heat only if he keeps the volume the same, but warmer if he turns it up.



dadkins
Can you do Blu?
Premium,MVM
join:2003-09-26
Hercules, CA
kudos:18

At max volume setting, the amp will run cooler with 8 OHM speakers than it will with 6 OHM speakers.

Less load = Less heat.
--
Think outside the Fox... Opera



jim61

join:2000-09-10
Vermilion, OH

1 recommendation

Quote from another forum:

Your receiver feeds voltage to your speakers. For every volt that it feeds to an 8 ohm speaker it will have to deliver one eighth of an amp. Current equals voltage divided by resistance; that's Ohm's law. (We'll skip the complexities of reactive loads for now.)

The good news is that your receiver was designed for 6 ohm speakers. This means that it is capable of delivering one sixth of an amp for each volt. It can but, with eight ohm speakers, it doesn't have to. As pdq points out, it doesn't have to work so hard. The only drawback is that you will get less power - for which read less volume. Power equals voltage multiplied by current. Your receiver feeds the same voltage to your 8 ohm speakers but you only get 75% of the current that you would have got with 6 ohm speakers.

It's like having a light fitting marked "Max 100 watts" but you've only got a 75 watt bulb. That lower power bulb won't damage your light fittimg but it won't be as bright either. Actually, reducing your power by 25% isn't nearly as bad as it sounds. It's only 1.25 decibels and most people (apart from the audio experts on this forum) would hardly notice unless you told them. Just turn the volume up a bit.



dadkins
Can you do Blu?
Premium,MVM
join:2003-09-26
Hercules, CA
kudos:18

Thank you!



IllIlIlllIll
EliteData
Premium
join:2003-07-06
Hampton Bays, NY
kudos:7

1 recommendation

reply to batsona

just dont do the reverse.
you would not believe the amount of shorted amplifier units i get in my shop from customers connecting 4 ohm spkrs to 8/16 ohm amps that crank the volume up for long periods and those that connect 2 or more 4 ohm spkrs per channel to an 8/16 ohm amp.
i see this very often with car amps.
--
S.C.P.D. Live Scanner Feed
N.C.P.D. Live Scanner Feed



Anonymous_
Anonymous
Premium
join:2004-06-21
127.0.0.1
kudos:2
Reviews:
·Time Warner Cable

4 edits
reply to batsona

should be no issuse i run 4ohm Speakers with no issuse(back speakers)

front speakers L-R are 3Ohms Center is 6ohms

(Sub is 3ohms)

the APM is speakers only = 8ohms
/ SUB only = 4ohm

it gets to 0C at night here so heat is not an issuse

i have yet to fry the reciver IT's FROM WAL-MART too
lenoxx HT-395