Wattage beyond rated thd wattage...

[PDXooo]

Hey guys - what's up?

Please - can anyone tell me - if an amplifier is rated 50W RMS @ 4ohms THD .005, how much Power would there be at say a THD of .1 or 10?

(IS THERE USABLE WATTAGE BEYOND RATED WATTAGE? )

Let me know please - Thanks...

[KingPen]

Yes there is but it starts to get into distortion. Cheater amps use to use this method by saying it did 100w at .005% distortion where at 1% it was more like 5k. The amount is impossible to generalize. You just need to test it.

[PDXooo]

Situation is - I thinking of getting a Sony amplifier, but I fear I may loose the wattage I intend for my speakers due to low voltage & high ohms due to climate & voice coil heating, & I wanna know if I'd actually get more from the amp instead... Say the am IS 50W RMS @ .005 THD - will I get 60W RMS out of it by say increasing the input voltage slightly? Thanks...

[KingPen]

what are you trying to power? Is a slightly larger amp in your budget?

[PDXooo]

Would you believe more wattage is cheaper? Problem is Amperage... I have a 100A class D option against a 140A class AB option & I want to go with the class D - that's my main desire - it's just that Sony only has like one 'affordable' class D 4 channel amplifier out at the moment(& I live in a hot climate that adds about an ohm of resistance to voice coils by default)making my options extremely limited...

[KingPen]

What is your other option? What is your budget. Not sure I've ever recommended a Sony amp to someone.

[PDXooo]

The other option is still Sony - lol - just a class AB 4 & 2 channel amp(s, instead of a class D 4 & monoblock amp)... The class Ds together cost about $310 & the ABs about $230... The Ds take up less space but the ABs have better HP crossovers...

[KingPen]

Have u looked at PPI yet?

[PDXooo]

Yes I have - I've looked at many brands - it's just that Sony made a change in their product line & I decided to buy their product... Sony has a forum where you can make suggestions on their products & they listened to a suggestion I made(which I am very grateful for) - you follow me? I'm a loyal customer kind of guy... So - in an amplifier with 50W RMS 95W peak - could the RMS wattage go beyond rated? & if yes can you guess & tell me by how much? Thanks...

[KingPen]

I understand what your saying. So the simple answer is yes but in your situation it is not applicable.

[PDXooo]

Please elaborate on 'not applicable' - thanks...

[KingPen]

Meaning your not going to see over 50 watts with that amp where in another situation with a different amp you could see much more. If you exceed the point of distortion on that amp you will quickly be in clipping. Every manufacturer and product will be different. This particular unit is not one you will see the difference with

[PDXooo]

Ok... I understand that... So - do you know of any Sony amplifiers I'll be able to see the difference with, or only PPI? Please list or link me to the model - thanks...

[KingPen]

Lsn't one know for it either. If you need more power you should purchase a larger amp. But the difference between 50 and 60 watts is negligible. You probably won't even be able to hear the Difference. Also note you don't need to match Speaker and amp RMS. You are better to have an oversize amp. Buy a 100w per channel amp if u want to be on the safe side

[666WMD]

Going beyond the rated THD doesn't mean you'll have distortion, and yes you will see more power if you do. Audible distortion is usually around 3-5%THD. An amplifier rated at 0.05% will continue to increase in power up to about 20% before it starts to give a soft clip.
The only reason manufacturers rate their amps at such a low THD is to make them look good, because the uneducated public believes the lower THD rating directly relates to sound quality. In essence it does, but only Superman would be able to audibly hear the difference between 0.05% and a full 1%THD. It all just marketing hype.

If you are dead set on buying Sony, they have the XM-N1004 rated at 70wrms x4 @ 4ohm for $150 on Sonic Electronix or the XM-ZR704 rated the same on Woofersetc. The 1004 is 3" shorter than the 704, and the compact XM-4S is 3" shorter than that but $100 more.

[PDXooo]

Yeah - 666 - thanks - that's the data I was looking\hoping for... & the toss up is between the XM-4S(which uses 40A), it's twin(the XM-1S), the XM-ZR704(which has a better xover but is bigger & uses 50A)& the XM-GTR2202... The first 2\combo use\s 100A the second 130A & I'm concerned on the amperage because my current amp uses 40A & my fog lamps dip with bass - even though my headlights are off... But I'm coming to my final decision thanks to your help...

[666WMD]

A good indication of what an amp will produce is the fuse rating. The bigger the fuse, the more power it will produce. Though Class D will produce more power than a Class A/B for the amperage it draws. So the XM-ZR704 and XM-4S would probably be on par (I'm guessing the XM-4S is Class D to the 704's A/B), and the sub amps you want are comparable as well. I think it'd come down to which pair you like the look of more.

Have you done anything to your electrical system? Big 3 and an AGM battery should solve your dimming problems.

[PDXooo]

Done the big three - but if it means anything my wires are not soldered - they're clamped by bolts... I also have a capacitor but it's too far from my amp to truly matter(very limited space)... Looking into getting LEDs for lighting - & with my planned upgrade I'll need'em... Oh & my alternator does 98A...