You are here

Log in or register to post comments
nikitos
nikitos's picture
Offline
Last seen: 2 years 1 month ago
Joined: Sep 27 2012 - 8:01pm
What impedance speakers for my vintage amp?

Hi all,

So I cheaper out and purchased some vintage equipment for my first setup - a Rotel RA1500 TT and an Akai AA5000 integrated amplifier.

The amps is apparently rated at 45 watts per channel at 4 ohms and 30 watt at 8 ohms. So could you please tell me what kind of speakers will serve this amp the best?

Thank you

jackfish
jackfish's picture
Offline
Last seen: 1 year 1 month ago
Joined: Dec 19 2005 - 2:42pm
Any loudspeaker with a nominal impedance of 4 to 16 Ohms

and a sensitivity of 85dB/1w/1m or higher will work with that amplifier. If you have a largish room you probably should consider sensitivity above 88dB/1w/1m.

commsysman
commsysman's picture
Offline
Last seen: 2 days 21 hours ago
Joined: Apr 4 2006 - 11:33am
SPEAKERS

Most speakers will be in the 4 to 8 ohm range, so impedance is not the problem.

I would definitely suggest that you get speakers with high sensitivity, preferably 90 db/watt or so, since the power rating is relatively low. 

The Monitor Audio Bronze BX-2 or BX-5 would be good choices.

KEF and Wharfedale are other good ones to consider.

Check Carlton Audio-Visual in Australia and AVAustralia.

nikitos
nikitos's picture
Offline
Last seen: 2 years 1 month ago
Joined: Sep 27 2012 - 8:01pm
Hmmm ok, I guess I need to

Hmmm ok, I guess I need to learn what speaker sensitivity is!

Thank you! Any more light and knowledge!?

commsysman
commsysman's picture
Offline
Last seen: 2 days 21 hours ago
Joined: Apr 4 2006 - 11:33am
SPEAKERS

Speaker sensitivity is rated in db/watt/meter.

This is determined by applying 1 watt of power to the speaker and measuring the loudness in acoustic decibels, or dbA, 1 meter in front of the speaker with calibrated instruments.

Each 3 db change represents twice as much. Each 10 db is 10 times as much (the scale is logarithmic).

For example, a speaker rated for 90 db/w/m is twice as sensitive as a speaker rated 87 db/w/m.

40 watts of power applied to a speaker with 90 db/w/m with give an acoustic output of 3db + 3db + 10 db +90db = 106 dbA. To get that same sound level with a speaker rated at 87 db/w/m will require 80 watts of power from the amplifier.

Another way of looking at it is this; a speaker with a 87 db/w/m rating needs twice as much amplifier power as one rated 90 db/w/m to produce the same amount of sound.

A less sensitive speaker needs a lot more amplifier power to give the same result.

With your relatively low-powered amplifier, speakers rated 90 db/w/m or higher will most likely give you plenty of loudness. If you get less sensitive speakers, your amplifier may be inadequate.

 

nikitos wrote:

Hmmm ok, I guess I need to learn what speaker sensitivity is!

Thank you! Any more light and knowledge!?

  • X
    Enter your Stereophile.com username.
    Enter the password that accompanies your username.
    Loading