Can I drive 4 Kplisch RB-81 speakers with my NAD C-352?

[Gankette]

Forum Members:

Thanks for hearing me out.

I own a NAD C-352 integrated amp (80 watts at 8 ohms) and have a pair of Kplisch RB-81 speakers. The combo sounds great.

I am thinking of adding another pair of speakers (in the same room, the idea is to get a fuller sound). The NAD amp has outputs for 4 speakers.

Questions:

Is the NAD 2352 powerful enough to drive 4 speakers of the size/efficiency of the RB-81? At a loud (ish) level?
Do I need a more powerful amp?
Since the RB 81 is discontinued, I was thinking of buying RB-81 II speakers--a direct succession. Good idea?
What other speakers would match well with my RB-81s? I like bookshelf designs.
What other considerations should I be aware of?

With many thanks,

Gankette

 

[Ugg10]

The RB81 are quoted at a nominal 8ohms but no details on their minimum impedance which is the important number to look for. The Nad only has two stereo channels therefore by adding two pairs of speakers you halve the nominal impedance therefore two 8 ohm speakers is the same as one 4 ohm speaker, the lower the speaker impedance the harder the amp has to work to generate the sound. If the minimum impedance is say 5 ohms at some points in the frequency range the amp will be driving 2.5ohms which is not a very good idea Especially at louder levels.

The Nads tend to have decent power supplies there theoretically four speakers like the RB81 can be run off that amp.

However, having two pairs of stereo speakers in one room is generally not a good idea, any sound stage size (ability to determine where instruments are left and right or front to back) will be lost and it will all sound a bit mono all coming from one source and may sound more muffled. We’re you planning on putting them both in front or having then in the four corners of the room, either is not a good idea generally. If you want a more immersive experience the putting the cash into a decent pair of headphones and maybe a headphone amp may be the way to go

Just my 2p worth.

 

[muljao]

If you want a bigger sound you'd be better getting bigger speakers rather than running two sets

 

[Gankette]

The RB81 are quoted at a nominal 8ohms but no details on their minimum impedance which is the important number to look for. The Nad only has two stereo channels therefore by adding two pairs of speakers you halve the nominal impedance therefore two 8 ohm speakers is the same as one 4 ohm speaker, the lower the speaker impedance the harder the amp has to work to generate the sound. If the minimum impedance is say 5 ohms at some points in the frequency range the amp will be driving 2.5ohms which is not a very good idea Especially at louder levels.

The Nads tend to have decent power supplies there theoretically four speakers like the RB81 can be run off that amp.

However, having two pairs of stereo speakers in one room is generally not a good idea, any sound stage size (ability to determine where instruments are left and right or front to back) will be lost and it will all sound a bit mono all coming from one source and may sound more muffled. We’re you planning on putting them both in front or having then in the four corners of the room, either is not a good idea generally. If you want a more immersive experience the putting the into a decent pair of headphones and maybe a headphone amp may be the way to go

Just my 2p worth

 

[password1]

If 2 speakers isn't filling the room, you need larger speakers.

As stereo music is recorded for 2 channels, duplicating.both channels will mess up the sound stage.

The exception would be dance/house type music where the positioning of vocals and instruments perhaps isn't as important.