what impendence am i acheiving that a 49-51 hz tone?

[Dirtrider4eva 10+ year member]

So I should be measuring it at my max volumes and low volumes?

Or can I derrive a parabolic function bassed on the slope of the two points?

I just want to know if I can use my sub at .6 ohms at a 50hz tone. Box is 4cubes, tuned to upper fourties, .sub is aq hdc3 15 a coils

 

[shizzzon 10+ year member]

This is going to sound like a worthless paradox..

But the only way to measure the impedance curve accurately is when you are playing that 50hz tone...

But if you are playing that tone.. then obviously it WILL play it...

So the question should be what will be impedance curve look like at 50hz?

And the question i have for you is, why do you need to know?

I am assuming you are wanting to know about 50hz because you will burp there.

Well.. burping is so quick when done properly that many competitors actually burp under 1ohm on 1ohm stable amps, actual impedance reading.

I'm not condoning the safetyness of it because it all depends on time and current\voltage..

But 0.6ohm is not drastic by any means.

A lot of us competitors may actually choose to run their equipment at that DCR load for daily.

Again, not saying you should because I know from this post you do not have the experience in knowing what to sense for but for burps, there should be no worry whatsoever as long as your amp is 1ohm stable.

The only way I could see a potential problem is if you were tuned to like 35hz and trying to burp at 80hz...

The closer your tuning and burp note is, the more likely your impedance curve at that point will be pretty high.

Example- I had a box 7yrs that was 8cuft for 1 15 on a 1500w amp.

Tuned to 29hz, burp at 31hz.

Wired at 0.7DCR

Burped at 4.2ohms

 

[Moble Enclosurs 10+ year member]

I peak at 49-51 in my car, im running a dvc 1.2ohm, and ita strapped on 2 aq1200s, I want to know If I could burp it when dropped to .6ohm, and only at my specific 49-51hz tones?.because if the impedence at those specific tones are useable I would do that for comps..

Even if the impedance is within range of the amplifier, you have to consider excursion of the driver as well and the phase correlation also. Once these are figured, and within range, you will be able to know if you can fully use the potential of the system for specific frequencies. Just some other things to look at as well if you can.

 

[Moble Enclosurs 10+ year member]

This is going to sound like a worthless paradox..
But the only way to measure the impedance curve accurately is when you are playing that 50hz tone...

But if you are playing that tone.. then obviously it WILL play it...

So the question should be what will be impedance curve look like at 50hz?

And the question i have for you is, why do you need to know?

I am assuming you are wanting to know about 50hz because you will burp there.

Well.. burping is so quick when done properly that many competitors actually burp under 1ohm on 1ohm stable amps, actual impedance reading.

I'm not condoning the safetyness of it because it all depends on time and current\voltage..

But 0.6ohm is not drastic by any means.

A lot of us competitors may actually choose to run their equipment at that DCR load for daily.

Again, not saying you should because I know from this post you do not have the experience in knowing what to sense for but for burps, there should be no worry whatsoever as long as your amp is 1ohm stable.

The only way I could see a potential problem is if you were tuned to like 35hz and trying to burp at 80hz...

The closer your tuning and burp note is, the more likely your impedance curve at that point will be pretty high.

Example- I had a box 7yrs that was 8cuft for 1 15 on a 1500w amp.

Tuned to 29hz, burp at 31hz.

Wired at 0.7DCR

Burped at 4.2ohms

Precisely. There are MANY cases that even if the amp is capable of min 1ohm, people have burped a lot lower. But I'm not saying this is a good idea to try if you are very concerned with damaging equipment. Just saying it's been done no problems. But likely due to the knowledge of what that .6ohms WILL do, and to those who hvae done it, Im sure it wasn't just guess work either.

 

[Dirtrider4eva 10+ year member]

Well the amps are strapped.. so technicslly 2 ohm

Im not to worried about the excursion and phase at this point.. R

I want toknow if I can do thst.lol. Thats it.

 

[Dirtrider4eva 10+ year member]

anyone brah

 

[wenn_du_weinst 10+ year member]

relying on impedance rise to save your amps is a sure fire way to fry them

 

[Moble Enclosurs 10+ year member]

That is probably why no one answered right away, because we have told you that all of those factors are important, but then you said you did not care about them. . When you are considering a burp, you have to consider everything involved in what it takes, and excursion and phase and correct impedance matching are very important to understand and know what your design does for each of those. We just don't want you to damage the gear is all.

 

[Dirtrider4eva 10+ year member]

im not saying i dont care. but its not that simple. going around an answser isnt what i asked for. going from .6 ohms..

im not relying on rise. im trying to figure out if I can play a 49-51 hz tone with my sub at .6ohms on a 2 ohm stable strapped amp.

isnt the tone at a higher volume going to pull up the impedence drastically?

excursion is only going to increase the impedance i thought..

how does phase play such a large factor?

 

[shizzzon 10+ year member]

you are not relying on "rise" but you expect a tone at a hgih volume to "pull" the impedance up?

You are talking in circles now..

Now since i know you are strapping at a stable load of only 2ohms.. wiring to 0.6 DCR, is NOT SAFE.

You might be able to get by with it but the amount of current that will be produced internally will\can eventually meltdown the Fets, etc...

 

[Dirtrider4eva 10+ year member]

you are not relying on "rise" but you expect a tone at a hgih volume to "pull" the impedance up?
You are talking in circles now..

Now since i know you are strapping at a stable load of only 2ohms.. wiring to 0.6 DCR, is NOT SAFE.

You might be able to get by with it but the amount of current that will be produced internally will\can eventually meltdown the Fets, etc...

alrighty, there and done. thanks.

 

[Moble Enclosurs 10+ year member]

im not saying i dont care. but its not that simple. going around an answser isnt what i asked for. going from .6 ohms..im not relying on rise. im trying to figure out if I can play a 49-51 hz tone with my sub at .6ohms on a 2 ohm stable strapped amp.

isnt the tone at a higher volume going to pull up the impedence drastically?

excursion is only going to increase the impedance i thought..

how does phase play such a large factor?

I see you got your answer, so I am going to edit this to say....good luck.

 

[Dirtrider4eva 10+ year member]

sub is face and port to hatch. i drive a 2000 celica hatch..

if the amps shouldnt be run that low. i wont do it. easy enough.

i just thought if the tone played acheived an impedence of over 2 ohms.. i shouldnt have a problem. i darn well know that playing at a 2.4 ohm woofer, plus rise, plus tone rise, and all those other factors are easilly pushing me up a few ohms. if i am correct.

 

[Dirtrider4eva 10+ year member]

also, if there is someone who wants me to tell them a ton of variables needed to help me calc this out. ill do it..

i got the box plans, obviously can take measurements, etc.

but im doing what i know.ha.

 

[FtheNutHuggers]

No worries. My specialty is more in acoustics rather than home electronics anyhow, so I have some learning in that field when it comes to circuits, but I assure you, anything car related or sound related in acoustical reproduction in car or home audio, watch out. Lol.

How are you calculating the effects of kinematic viscosity, (velocity profile in general), resonant impedances, phase of impedance and impedance effects of geometry of trunks, hatches, rear seats, rear window and seating location?