sindaygostl

I WENT TO A SHOP THE OTHER DAY TO LOOK FOR AN AMP I ASKED THEM IF THEY HAVE ANY OTHER TYPE OF AMPS FOR SQ. BESIDES JL AUDIO. I ALSO SAID THAT I WANTED A D CLASS AMP, THE GUY TOLD ME IF I WANT TO HAVE SQ GET AN AB AMP HE SAID D CLASS AMPS ARE SMALL AND STAYS COOLER THAN AB BECAUSE THEY ARE FOR SPL COMPETITIONS, NOT FOR SQ. AND NOW IM CONFUSED. WHAT DO YOU THINK IS BETTER??

dnd2984

iTrader: (6)

he is exacly right.

Class AB amps are made for speakers. THey have cleaner power than Class D

Class D do stay cooler, but there power is mainly made for subwoofers.

I know Xtant has a classD full range amp.

shawhite

ok here is how is goes... amps come in many classes... a class being the less efficent and best fidelity.... to d being the most efficent and the least fidelity... the reason class d amps are used for sub is the fact that they are very efficent.. hint the reason they stay cooler... and also the fact that fidelity is not a big concern when it comes to low freq... the new class t amps are suppose to have the best of both worlds.. extremly effecient with the fidelity of the class a/b amps... like dnd mentioned class d's are usually used on subs while classes a , b or a/b are used with components or door speakers... but that is not saying that you can not use a class a/b on subs.. personally i think it would be a waste of money since most human ears can not distinguish the difference in the 2 amps running subs but to each there own...

sindaygostl

WOW, T CLASS THE ONLY T CLASS AMPS I SEEN ARE THE VISONICS BUT THEY'RE OVER RATED. THEY ALSO MADE A X CLASS AMP.

OK SINCE WE GOT OVER THAT, WHATS THE DIFFERENCE OF A POWER AMP TO JUST A REGULAR D CLASS

GSteg

class A, A/B, B, D, T, G, etc does not have any affect on "sound quality". the classes may be different topologies, but it doesn't have anything to do with sound. they all differ in how they make power.

the distortion rate for a Class D sub amp shouldn't exceed 2% THD. even at 2%, you'll need test tones and a very good ear to distinguish he distortion. but since we listen to music, more reason for us to be able to hear such a thing.

i am willing to bet the salesman does not have any education in amplifier topologies and probably heard it from some mis-imformed person.

Bottom line: classes do not affect sound quality.

sindaygostl

OK, SO WHATS THE DIFFERENCE BETWEEN A POWER AMP TO A REGULAR SUB AMP. PEOPLE I TALKED TO SAID THE POWER AMPS HAVE NO SQ, THEY JUST GIVE HIGH SPL RATING. IS THAT TRUE?

shawhite

hey GSteg i would have to disagree... class have alot to do with fidelity (sound quality).... but i do agree that most people can not hear the difference... i have several electronics books here that will also state that class a amps will be less efficient and have a higher fidelity than class d amps...

GSteg

i'm not sure where the idea came from, but its the same concept as subwoofers. the topologies are different. some subs are underhang, overhang, evenhang, some uses the XBL^2 method, others use BL/Re^2, etc. but its not the topology that gives it away, its the suspension, motor as a whole, etc.


richard clark has an a double-blind A/B testing where u can choose your own amps (class D, class A, etc). he'll buy pass all the processing stuff like the amp's xover, EQ, etc so the only thing left is the amplifying section. til this day, no one has pass his test before. and if u do pass it, you'll be walking away with $10k. not bad eh?

now most class D's can't be used for midrange because of the impulse rate. some class D's are suitable for midrange though. the rest of the fidelity stuff comes from phsycoacoustics.

its kind of like how some people refer to tube amps as "warm" sounding.

shawhite

I will agree that people for the most part can not hear the difference in sound in most classes of amps... but i will bet you if you hook that output up to an oscope you will surely see the difference...

bozzchem

Go here for an in-depth discussion of the differences:

http://www.eatel.net/~amptech/elecdisc/caraudio.htm

Head over to the on-site search engine (#18 in the menu on the right hand side) and type in "amplifier classes" "type D" or something similar.

Perry will explain the differences of each for you.

shawhite

bozz i already know the difference... i am an ET i went to school for electronics.. one of my projects was to build a 4 stage power amplifier out of descret components (no ic chip)... i am not just saying something that i have heard... i have put in the book and lab time on this subject...

GSteg

well sure the o-scope would be able to tell the difference, but thats because distortion rate varies with every amplifier. now the end consumer are the ones that are going to be listening to the music, so its safe to assume that there are no audible differences within amplifier classes.

bozzchem

I don't remember saying anything to the contrary.

I was just providing sindaygostl an online resource that may answer his questions.