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dansk_84
05-15-2009, 10:58 AM
Hi Guys

Im pretty new to this whole speaker/amp/watt/ohms game so if some of my terminology is wrong please forgive me :D. Basically my question is want to make sure that the speakers i have chosen for my home built speaker cabinet are suitable for the power amp that will be powering them.

First of all ill show you the power amp i will be using.

I am planning to buy a Alesis RA300 power amp
http://www.alesis.com/ra300

The rated output per channel are:
* 4 ohms: 150 watts RMS per channel
* 8 ohms: 90 watts RMS per channel
* 8 ohms: 300 watts RMS, bridged mode

Now the speakers i am planning to use with this amp are 2 Celestion Vintage 30.
The specs of the speakers are shown below:

Power Rating 60W
Nominal impedance 8Ω and 16Ω
Sensitivity 100dB

Now if i run 2 16Ω speakers in parallel the total ohms will be 8, is that correct?
Next if running speakers in parallel will that double the wattage, so will the power rating amount to 120W?
Will is be ok to run 120W and 8ohms worth of speakers off a 8 ohms 90 watts RMS per channel?

I look forward to a to hearing your opinions

Dan

Feanor
05-15-2009, 11:17 AM
Hi, Dansk,

I have added some my answers below ...


Hi Guys

Im pretty new to this whole speaker/amp/watt/ohms game so if some of my terminology is wrong please forgive me :D. Basically my question is want to make sure that the speakers i have chosen for my home built speaker cabinet are suitable for the power amp that will be powering them.

First of all ill show you the power amp i will be using.

I am planning to buy a Alesis RA300 power amp
http://www.alesis.com/ra300

The rated output per channel are:
* 4 ohms: 150 watts RMS per channel
* 8 ohms: 90 watts RMS per channel
* 8 ohms: 300 watts RMS, bridged mode

Now the speakers i am planning to use with this amp are 2 Celestion Vintage 30. I'm not familiar with these speakers specifically, but I think I can answer.
The specs of the speakers are shown below:

Power Rating 60W For the home user, the maximum power rating of the speaker is pretty much irrelevant -- don't be concerned if your amp will supply much more power.
Nominal impedance 8Ω and 16Ω I think you mean they are 16 ohms each?
Sensitivity 100dB The overall sensitivity of the system will depend on the cabinet and cross-over network as well as the speakers themselves.

Now if i run 2 16Ω speakers in parallel the total ohms will be 8, is that correct? Yes, that's correct.
Next if running speakers in parallel will that double the wattage, so will the power rating amount to 120W? Yes, it will double the maximim power handling to 120 watts total.
Will is be ok to run 120W and 8ohms worth of speakers off a 8 ohms 90 watts RMS per channel? Yes, there's no problem running two 16 ohm speakers in parallel. (Note that the amp will "see" 8 ohms and deliver 90 wpc per its specification.)

I look forward to a to hearing your opinions

Dan

dansk_84
05-15-2009, 12:12 PM
Hi Feanor

Thanks for quick response and for clearing up them questions, it was very helpful. Ive found the whole speaker and amp subject quick confusing.

With reference to the part where i mentioned the resistance of 8ohms and 16 ohms i ment you can buy 8ohms and 16ohms speaker :D.