What do you know about a 100% DD setup?

[wickedwitt 10+ year member]

So you can sit in someone's car, take a blind test, and tell if the subs are playing at 2ohms or less based on distortion levels?

The difference between 2ohm and 1ohm, more than likely not. The difference in 2ohm and .25ohm, more than likely so. I'd be even more invested in the fact of the unnecessary strain placed on the electrical system, the amps themselves, and the woofers when running significantly low resistance configurations.

 

[audioholic 5,000+ posts]

The difference between 2ohm and 1ohm, more than likely not. The difference in 2ohm and .25ohm, more than likely so. I'd be even more invested in the fact of the unnecessary strain placed on the electrical system, the amps themselves, and the woofers when running significantly low resistance configurations.

Now we get to the meat of the discussion. Does amplifier topology or design play no role in THD at a given impedance? You think you can hear the difference netween a class A/B at 2ohms and a class D at .5ohm? Can you explain how 10000 watts @ 1ohm places significantly more strain on a charging system than does 1000 watts @ 8ohms? Lastly, how does 1000 watts fed to a subwoofer at .25 ohm kill it faster than 1000 watts fed to a sub at 8ohms?

 

[LosIsATool 5,000+ posts]

Pot. Kettle. Black. Just because you don't know anyone that can clamp 8k+ at 2ohm with their Warhorse with DSP (a wonderful signal integrity device), doesn't mean I won't be able to. Trust me, I'll be putting clamp results up here for everyone to see just exactly what I get. If I get 9500 at 13.8v wonderful. If I get 7500 at 13.8v wonderful too.
Your logic is backwards here. .25 ohm daily is stupid. It stresses an electrical system, provides a greater opportunity for amp failure, and by extension woofer failure. It also, technically reduces sound quality, but people already care so little about true SQ with sub frequencies they play 'SQ' subs at 4ohm and less. I would never run a sub at less than 2ohm for daily and never run a mid at less than 4ohm. If I could get the power I wanted, I would run 4ohm for subs and 8ohm for mids, but we have yet to get into a world where 8k at 4ohm and 1200w at 8ohm is easily achieved.

tl;dr Don't know about you, but I like my music to be loud and have a good sound

JBL Crown

 

[Falcons 5,000+ posts]

its gettin mad serious in this thread

 

[LosIsATool 5,000+ posts]

Now we get to the meat of the discussion. Does amplifier topology or design play no role in THD at a given impedance? You think you can hear the difference netween a class A/B at 2ohms and a class D at .5ohm? Can you explain how 10000 watts @ 1ohm places significantly more strain on a charging system than does 1000 watts @ 8ohms? Lastly, how does 1000 watts fed to a subwoofer at .25 ohm kill it faster than 1000 watts fed to a sub at 8ohms?

Yes.. You can tell the difference between a budget .5ohm and a quality 2ohm. Efficency. Higher THD

 

[audioholic 5,000+ posts]

Yes.. You can tell the difference between a budget .5ohm and a quality 2ohm. Efficency. Higher THD

So is the difference in the 'quality' or the impedance? Again, topology and/or design plays no role, right? .5ohm always sounds bad?

Generalizations have gained a bad reputation for good reason.

 

[LosIsATool 5,000+ posts]

So is the difference in the 'quality' or the impedance? Again, topology and/or design plays no role, right? .5ohm always sounds bad?
Generalizations have gained a bad reputation for good reason.

Not always. Just when a amp isnt designed for it. Im sure a MMATS .05 amp sounds better then running a AQ at .5

 

[Danometal 10+ year member]

It would seem to me that running an amp at an impedance near a dead short can't be good in the long run.

 

[audioholic 5,000+ posts]

It would seem to me that running an amp at an impedance near a dead short can't be good in the long run.

Define 'near a dead short'. Is an A/B at 2ohms closer, or further, away from a dead short than a D at 1ohm.

Again, generalizations have earned a bad reputation for a reason.

 

[Danometal 10+ year member]

Define 'near a dead short'. Is an A/B at 2ohms closer, or further, away from a dead short than a D at 1ohm.
Again, generalizations have earned a bad reputation for a reason.

A lot of fuses measure ~ .3 ohms. So, 2 ohms is obviously further from being a giant fuse than 1 ohm, no matter the topology, IMO.

 

[audioholic 5,000+ posts]

A lot of fuses measure ~ .3 ohms. So, 2 ohms is obviously further from being a giant fuse than 1 ohm, no matter the topology, IMO.

Obviously the ruse rating is all that matters.

 

[Danometal 10+ year member]

Obviously the ruse rating is all that matters.

Huh? Nothing I wrote has anything to do with fuse ratings, just random impedance readings I took with my DMM and some fuses (and wires, etc.) I was juxtaposing the fact that fuses are supposed to act without resistance... to an amp likewise being ran near the point of zero resistance. There's a reason nearly every amp company only advertises power output down to 1 ohm, and no less.

 

[sacsking916 5,000+ posts]

when holic enters the thread, shit gets real ha ha ha.

 

[wenn_du_weinst 10+ year member]

So if you were to build an SPL setup, you just start building boxes with total guesses? After choosing a sub by completely guessing as to its specs/capabilities? That's a lot of guessing, bro.
And even if I believed you, that still doesn't account for all those other people who aren't building an SPL setup.

You go to term pro and see how many burp cars go off of t/s, I'll save you the trouble none. Pretty much it is an educated guess to start off with. I can deff tell your old school by the way you talk.

Was this on a 16V setup? I can see that being the case. Do you by any chance have a link to the results? FWIW, people have clamped the original IA 40.1's at just under 8kw on a 16V setup.

m4a's will not run 16v they shut off at 15.5



and to wicked, don't blame me if your to scared to run .25 nominal daily I was running aq's do you think I was looking for sq? You have a picture of solox's in your avatar do not lecture me on anything revolving sound quality

 

[wickedwitt 10+ year member]

Now we get to the meat of the discussion. Does amplifier topology or design play no role in THD at a given impedance? You think you can hear the difference netween a class A/B at 2ohms and a class D at .5ohm? Can you explain how 10000 watts @ 1ohm places significantly more strain on a charging system than does 1000 watts @ 8ohms? Lastly, how does 1000 watts fed to a subwoofer at .25 ohm kill it faster than 1000 watts fed to a sub at 8ohms?

The difference is, it doesn't take near as many watts to get loud on an 8ohm system as it does a .25 ohm system. That is how you have less strain.

Also, the impedance question on it placing more strain on a charging system. Using: Amperage= √ (watts/ohms), you find that lower impedance does require more amperes; therefore, requiring more of an electrical system. As far as killing a speaker faster, it is obvious if it is fed below the impedance of the coils. If it is not below the impedance, I can't accurately describe why that would kill a woofer faster other than the general amperage data calculated by the formula I just used.

I would definitely say that amplifier design plays a role in THD, as being engineered to run at different ohm loads, the amps windings and resistors will be built differently. The effect of electrical current at said resistances (and voltages but it's unfair to talk of factor y when we are trying to isolate factor x) will be different.