Need some advice, I need to purchase a 4 channel amp the choice between sundown 125.4 or ice 150.4

The only thing that's holding me back from buying the sundown is I've just read its a D class compared to the SPL ice 150.4 which is a a/b class. Would there be a big difference in sound quality on my mid & tops? I use a sundown 1500d v3 on the bass but I need a 4 channel to go with it.

Thoughts please

Technically speaking, there's no difference in sound at all. In the early days of class D, full range amps were full of problems with upper end response that's true. The class D amps had to switch on and off (digital signal) at super high frequencies to get smooth high frequency output. Thats because it takes double (or more) on the digital signal to produce the equivalent output frequency (i.e. to produce a 10khz output frequency the amp would need a digital signal frequency of at LEAST 20khz). At least I think that's how I remember reading that.

Though today's full range class D amps are VERY commonplace and those limitations are gone with any amp that's worthwhile.

Now the SAX-125.4 is new, so very few can speak to their use of it, but I would imagine it's perfectly fine.

Wanted to add though, I remember CA&E doing a blind listening test with a tube amp, class d, class a/b, and a class T (or G, been a LONG time since I read it). All connected to the same source and speakers with a switch for the listener to switch between each one. The results were surprising in that everyone could consistently hear a "difference", although it was very slight and only the better trained listeners really noticed it. However that difference was finally attributed mostly to the front-end or input stage differences of the class d, a/b and t amps than anything else as it was measurable later in a lab. As far as listening tastes, especially at higher volumes, everyone liked the tube amp the best. The reasoning for that is the difference in how distortion works between a transistor and a tube.

That's if I remember that article correctly.

Wanted to add though, I remember CA&E doing a blind listening test with a tube amp, class d, class a/b, and a class T (or G, been a LONG time since I read it). All connected to the same source and speakers with a switch for the listener to switch between each one. The results were surprising in that everyone could consistently hear a "difference", although it was very slight and only the better trained listeners really noticed it. However that difference was finally attributed mostly to the front-end or input stage differences of the class d, a/b and t amps than anything else as it was measurable later in a lab. As far as listening tastes, especially at higher volumes, everyone liked the tube amp the best. The reasoning for that is the difference in how distortion works between a transistor and a tube.

That's if I remember that article correctly.

If that is the test from 5-7 years back, there were several problems with the test methodology that would render the results of that test void. It didn't "prove" anything.

There are only 5 things that can contribute to a "sonic character" of any amplifier, regardless of topology; Power, distortion, noise, frequency response and gain. For two amplifiers to sound different, there must be an audible (not just measurable, but audible) difference in one of these categories. Nothing else matters, literally.

It is entirely possible to build an amplifier of any of the usual classes (A, A/B, D, etc) where the distortion is inaudibly low, the noise is inaudibly low and frequency response is inaudibly flat. That leaves differences in power and gain structure. It is also possible to build an amplifier of any of the usual classes where the distortion is audible, noise is audible, or the frequency response has audible deviations.

What does this mean? The class of the amplifier doesn't mean anything. Two amps can sound indistinguishable, and two amps can sound different.....but it has nothing to do with the class of the amplifier and everything to do with the 5 items previously listed.

Psychoacoustics almost always have you picking the louder setup in an A/B comparison. Exactly how many high end shops promote the more expensive gear.

As for sonically telling the difference between amps, sure you can hear differences but not from the aspect of one that is better or worse only the differences in the categories that Imp described above.

I have all class D in my boat and everyone raves on how good it sounds. Of course I think it sounds like shit, but that isn't the amps fault. Lol

Psychoacoustics almost always have you picking the louder setup in an A/B comparison. Exactly how many high end shops promote the more expensive gear.

As for sonically telling the difference between amps, sure you can hear differences but not from the aspect of one that is better or worse only the differences in the categories that Imp described above.

I have all class D in my boat and everyone raves on how good it sounds. Of course I think it sounds like shit, but that isn't the amps fault. Lol

I knew you liked royal purp, but didn't know to that extent.

Edited October 31, 201212 yr by stefanhinote

Toooo funny Stefan....LOL!

Edited October 31, 201212 yr by chicagofan

If you already have a Sundown , get a second one for the look, at least !!! And don't forget D class amps are less hard on the electrical.

But I know SPL D is big in Europe, and easily available .