Mono-block amplifers fact and fiction

[cal 10+ year member]

Class D are more efficient at lower ohm loads than Class AB, but at high ohm loads that isnt true. Also Class D amps sound just as good as Class AB if you buy a quality Class D amp.

well, ive been doing some research and have not seen many of these amps you speak of with less than .1 thd and before the class d most amps were .05 or less . again its just a simple comparison and not saying newer amps are not as good. for example my audiosystem amp is considered a higher quality amp and its @1. thd so go figure .

 

[winkychevelle 10+ year member]

well, ive been doing some research and have not seen many of these amps you speak of with less than .1 thd and before the class d most amps were .05 or less . again its just a simple comparison and not saying newer amps are not as good. for example my audiosystem amp is considered a higher quality amp and its @1. thd so go figure .

and this is why u buy an amp with head room

an amp that puts out 100w at .1%thd isnt really bad spec wise if u are using 50w which could possibly be the .005%thd you are talking about if you remember in the past alot of amp were seriously underrated and since they were rated for 50w at .005% but actually push and were used at 500w what do you think happened to the amps thd when it was driven harder? it when up of course

 

[quackhead 10+ year member]

well, ive been doing some research and have not seen many of these amps you speak of with less than .1 thd and before the class d most amps were .05 or less . again its just a simple comparison and not saying newer amps are not as good. for example my audiosystem amp is considered a higher quality amp and its @1. thd so go figure .

The advancement of technology in the power supply switching devices is just beginning to allow the best Class D's to approach so so Class A/b THD levels at higher frequencies. There again it depends on how the manufacturer presents the rating. Example: .08% at 1watt/4ohms or

 

[cal 10+ year member]

and this is why u buy an amp with head room
an amp that puts out 100w at .1%thd isnt really bad spec wise if u are using 50w which could possibly be the .005%thd you are talking about if you remember in the past alot of amp were seriously underrated and since they were rated for 50w at .005% but actually push and were used at 500w what do you think happened to the amps thd when it was driven harder? it when up of course

nope i dissagre do you remeber when fosgate and a few others had birth sheets? if they did not meet the thd they did not pass . i have a few old birth sheets that show true power not underated and meet thd ratings . im not going to argue this as it does not help op and this is the 3rd time i say it newer amps are not bad just not the same thd as older class ab is all .

 

[quackhead 10+ year member]

nope i dissagre do you remeber when fosgate and a few others had birth sheets? if they did not meet the thd they did not pass . i have a few old birth sheets that show true power not underated and meet thd ratings . im not going to argue this as it does not help op and this is the 3rd time i say it newer amps are not bad just not the same thd as older class ab is all .

What do you think of the Class G/H ?

 

[winkychevelle 10+ year member]

nope i dissagre do you remeber when fosgate and a few others had birth sheets? if they did not meet the thd they did not pass . i have a few old birth sheets that show true power not underated and meet thd ratings . im not going to argue this as it does not help op and this is the 3rd time i say it newer amps are not bad just not the same thd as older class ab is all .

and yet the birthsheets where measured at 4ohm on a perfect 14.4 electrical and with a resistor load. i agree the old amps were built like tanks but look at the money paid for them back then and now factor in inflation and look in that price range.

personally i wont run a high current amp in my car from the 90s but to be fair the fosgate powered 12 i just put in my car has a 300w high current amp built in its running at .5 bridged straight from fosgate

 

[cal 10+ year member]

What do you think of the Class G/H ?

to be honest ive been doing more research on my mono amp so i dont know what that is . also when i look to buy something i do alot of research. dont get me wrong im no engineer, i just goggle before i buy and do alot of reading . back in the day when class ab was the only thing around and most decent amps pretty much carried the same price tag what seperated them was the the thd and rms ratings .

 

[rebelfromva 10+ year member]

and yet the birthsheets where measured at 4ohm on a perfect 14.4 electrical and with a resistor load. i agree the old amps were built like tanks but look at the money paid for them back then and now factor in inflation and look in that price range.
personally i wont run a high current amp in my car from the 90s but to be fair the fosgate powered 12 i just put in my car has a 300w high current amp built in its running at .5 bridged straight from fosgate

what amp is this?

 

[cal 10+ year member]

and yet the birthsheets where measured at 4ohm on a perfect 14.4 electrical and with a resistor load. i agree the old amps were built like tanks but look at the money paid for them back then and now factor in inflation and look in that price range.
personally i wont run a high current amp in my car from the 90s but to be fair the fosgate powered 12 i just put in my car has a 300w high current amp built in its running at .5 bridged straight from fosgate

i agree 100 percent as every amp in my car is korean built . as for the price tag u cant compair american made with korean labor. also caraudio in the 90,s was more about low power, these days its all about big power and low cost .

 

[TheUnderFighter 10+ year member]

Not sure what your "friend in the business" was talking about. But a mono amp, is an amp with 1 channel. Most tend to be Class D. And most modern ones tend to be 1 ohm stable. It's all stated in the specs.

Was there something you had a question about specifically?

 

[av83 10+ year member]

Class D are more efficient at lower ohm loads than Class AB, but at high ohm loads that isnt true. Also Class D amps sound just as good as Class AB if you buy a quality Class D amp.

The good full range class Ds are good. JL HDs, ZED, Alpine PDX, Hertz to name a few. I feel something is missing but most audiophiles love them

I have a Kenwood Excelon XR-4S (it's a 120X4 class d) that I let sit around for months without ever hooking up (other than to test when i bought it off craigslist). Figured it would sound like crap on the highs. I finally hooked it up.... and was blown away. Sounded as clean as my Eclipse, and has 3x's the power. And it's tiny, to boot.

 

[winkychevelle 10+ year member]

what amp is this?

its the amp built into the p300-12 and p300-10 loaded enclosures i popped the sub out to set the gain and was surprised to see a .5ohm voice coil and a two channel amp bridged still is pretty efficient though 30amps of fusing and im only using 10guage knu speaker wire for power and ground run straight to the batt for no bad ground problems

 

[rebelfromva 10+ year member]

its the amp built into the p300-12 and p300-10 loaded enclosures i popped the sub out to set the gain and was surprised to see a .5ohm voice coil and a two channel amp bridged still is pretty efficient though 30amps of fusing and im only using 10guage knu speaker wire for power and ground run straight to the batt for no bad ground problems

hmmmm. I'd like to see pics of this

 

[winkychevelle 10+ year member]

hmmmm. I'd like to see pics of this

if i happen to take it back out soon which hopefully the car will be getting a headunits shortly and i will need to reset the amp anyway ill take a pic of it. its literally just two pcb boards with transformers and such on it no heat sinks. i suspect the amp would blow before the sub.

the loaded enclosure isnt really loud but its ok for my daily driving im planning on a ia flatlyne in a custom ported box and an ia 5.1 and 3.4 with the ia comps but the 3.4 is still in the works so this is just to hold me till then

 

[srb 10+ year member]

Why are all the op's posts in bold?