Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
My Receiver is 75 watts (speaker ?)
- Thread starter benlee
- Start date
- Sort by reaction score
you probably wont have a problem. unless you bought a fairly expensive receiver, your receiver really isnt 75 watts a channel especially with all channels driven as would likely be the case when your surrounds are running
the receiver manual says 75 watts per channel rms into 8 ohms, 2 channels driven, 20 Hz to 20 kHz,....
says can connect speakers with an impedance of between 6 and 16 ohms. Whereas, speaker says Nominal Impedance: 4-8 ohms.
Roughly, the watts your amp puts out doubles as the impedance (ohms) is halved. so 75W at 8 ohms, 150W at 4 ohms. Speakers are not uniform in their impedance across all frequencies, yours appear to vary from 4 - 8 ohms depending on the frequency of the tone. Speaker Watt ratings should be comfortably higher than the amp driving them.
Your amp has the potential to blow out the speakers, so restrict the volume control to half way or under and DON'T crank the bass or engage the loudness compensation switch at high volume.
The other issue is that inexpensive amps/receivers tend to have a lot of distortion at the higher end of their power range. A distorted signal at 50 watts can do more damage to speakers than a clean signal at 50 watts.
Your amp has the potential to blow out the speakers, so restrict the volume control to half way or under and DON'T crank the bass or engage the loudness compensation switch at high volume.
The other issue is that inexpensive amps/receivers tend to have a lot of distortion at the higher end of their power range. A distorted signal at 50 watts can do more damage to speakers than a clean signal at 50 watts.
Hi
To the original poster. Typically, home audio is rated at 6 or 8 ohms and automotive is rated at 4 but some raise it to 6 ohms.
My normal formula is to match the RMS power of both the amp ( per channel ) to each speaker. Not perfect but rarely it can be...If ever. Matching peak wattage is not a very good idea because, as you pointed out, it is extreme difficult to determine what true efficiency an amp can perform when even getting close to it's tested "peak" power output. Reasonable efficiency to maintain a continuous output power level may drop off after 50% of peak volume or even less on cheaper quality amplifiers / receivers.
To the original poster. Typically, home audio is rated at 6 or 8 ohms and automotive is rated at 4 but some raise it to 6 ohms.
If your amp is only rated down to 6 ohms and the speakers as low as 4 ohms you risk damaging the amp, as it requires more work from the amp to run low-impedance speakers.
If you decide to risk it, like others have said, careful with volume, as you could destroy the speakers. I can drive my 110 continuous/440 peak watt rated speakers to damaging levels with my 120w/channel amp pretty easily.
Hi
) to be able to confirm that for you. It's much quicker for a speaker to burn out as the cooling mechanism for the voice coil isn't designed for overheating and only for normal operation. So, it is quite easy to "burn" a speaker.
Anywho...
If you do decide to "risk it," I honestly don't see any permanent or otherwise worry-some damage affecting your amp though just listen closely the first time you test this setup for any distortion at your preferred volume level.
A little end FYI. Proper "break in" of brand new speakers is very important for maximum performance and lifespan. Break in procedures allow the surround and spider to be slowly stretched to full working potential without any tearing of the fibers.
Trying not to ramble. If the resistance ( ohms ) is significantly different, the amp may have to work that much harder. I don't see this being that big of a problem nowadays as most semi-current amplifiers ( including receivers ) have overload and overheating protection that will turn off the amp 99.9% of the time before anything of worry will happen. I also don't see too much with this one but another way is excess energy required by the amp when a speaker is either notably under or over powered, it creates overheating by having the voice coil exceed it's maximum range of motion ( xmax ). The voice coil stops moving forward for a moment, thereby creating heat from resistance and thereby also wear. This also happens again during the same cycle when the voice coil moves backwards and stops. This is what "burns out" a speaker and also causes distortion ( distortion is caused by the speaker not moving fluently ). Prolonging this heat buildup puts extreme wear on the speaker and soon it will not be able to perform properly and will always sound distorted ( at any volume level ). I would think in theory if the overload / overheat protection isn't quite sensitive enough in the amp, that this prolonged slow buildup could possibly damage it though I've never pushed an amp that far ( one or two speakers maybe
) to be able to confirm that for you. It's much quicker for a speaker to burn out as the cooling mechanism for the voice coil isn't designed for overheating and only for normal operation. So, it is quite easy to "burn" a speaker.Anywho...
If you do decide to "risk it," I honestly don't see any permanent or otherwise worry-some damage affecting your amp though just listen closely the first time you test this setup for any distortion at your preferred volume level.
A little end FYI. Proper "break in" of brand new speakers is very important for maximum performance and lifespan. Break in procedures allow the surround and spider to be slowly stretched to full working potential without any tearing of the fibers.