class d amps and 4 ohms and below speakers?

[stpierre76]

Hi all,

I was told or read more like it, that class d amp don t generally fair well with 4 ohms speakers expecially if they dip below 2 ohms?Is that true?And why?How does it affect the amp or sound.

Also, if this is the case how deos that differ from solid state amps?

regards

 

[ID.]

AFAIK they are solid state amps (as opposed to tube amps), although I think most solid state amps are traditionally class A/B.

 

[MattSPL]

You will probably find that a lot of amplifiers, be it class A, A/B or D, don't do very well with 4ohm speakers, unless they are rated to do so. And this generally costs a lot of money.

The problem being, that most 4ohm speakers will probably dip to 3, 2, or even 1ohm.

I had a Krell Kav300iL integrated amp. Rated at 200w/ch @ 8ohms, and 400w/ch @ 4ohms.
I used it with some B&W N803's that dipped to 3.2ohms i think it was. It was fine at normal listening levels, but caused massive heat from the amp and a loss of control in the bass when pushed really hard.

I had the same issue with some 4ohm PMC's on the same amp, but later upgraded to a Krell FPB200 that was stable at 2ohms. This was a massive improvement, even though the 8 and 4ohm wattage figures were the same as the integrated amp.

Chapter audio make some very nice class D amps that will drive 1ohm loads

 

[stpierre76]

thanks mattsl for your reply and input.very interswting.So how do i know what amp will perform admirrably with 4 ohm speakers that may dip below.

I am looking at the totem arros or may be neat motive se2.The arros are 4 ohms but not sure if stable or not.Don t know the neat, but thinkl 8 ohms.will look it up

sincerely yours

 

[MattSPL]

It will all depend on your listening tastes.

If you never listen at rock concert levels, then a 4ohm speaker should perform very well with a decent amp with good current ability.

Like the Krell integrated amp i mentioned above, at listening levels below very loud, it performed very well.
But if you want massive volume and bass control ability, then you need an amp that is stable below 4ohms. But then, the speaker has to be able for these volume levels too.

The neats are 6ohm i think.

Cheers

Matt