Impedance rise, not your typical question

[all4spl]

Ok I will try to make this simple, since I am sure there are a few on here with more knowledge than myself on this topic.

Here is my setup before the question, Old subs Dual 2ohm, wired parallel down to .5ohm during a burp at 51Hz I see rise (duh) up to 1.8ohm. New subs are dual .5ohm wired Series/Parallel down to .5ohm during a burp 51Hz I see rise up to 3.8ohm.

Now understandably there are going to be inherent differences in the subs as they are NOT made by the same company, nor are they same breed of sub. Old set are all ferrite magnet motor, the new set are ferrite with a neo ring. Older set of subs has less motor (size) than the newer subs.

My QUESTION is, can the rise I am seeing differ based on the way I have the .5ohm subs wired? Example current wiring is Series each sub then Parallel the subs together vs wiring them Parallel each sub and then Series the subs together. What I mean in case I am unclear is the wiring to achieve .5ohm nominal which can be done series coils per sub then parallel the outputs or parallel coils per sub then series that output.

Old Subs specs

New Subs specs

[hispls]

The ratio should be roughly the same for you if you say wanted to wire down to .12 ohm and hope the amp "sees" .6 ohm.

So you know any change may make that change. Move the box, change the port, open a window etc. Definitely changing subs and definitly even changing coils or suspension in the same sub. You should go to Partsexpress and buy DATS if you want to see where your impedance is at any given frequency. That is the correct tool for the job if you want to play the low impedance burp game.

[all4spl]

Term lab shows me the info so I don't need a DATS, so no I am not guessing what my impedance(s) are at burp.

And like my post states, this is a question of whether or not the way the subs are wired makes a difference.

[hispls]

Term lab shows me the info so I don't need a DATS, so no I am not guessing what my impedance(s) are at burp.

And like my post states, this is a question of whether or not the way the subs are wired makes a difference.

Termlab tells you, but not without potentially putting your amp in an unsafe state. Seriously, bro. If you can buy DD supercharged subs and a Termlab magnum 100$ for the DATS is peanuts and you'll totally get your money's worth out of it.

From my experience the ratio is close to the same though. For example, I was running D2.8 coil in series rising to @ 20 ohm, dropping to 1.4 rose to right around 4. That was being driven by a 4 ohm amp. I was at a DB Drag looking for a bit to beat the other guy in my class and that's the ONLY time I've really tried the wire at 1/3 rated impedance thing. As you probably know, it's risky business.

[all4spl]

Let me be clearer in my question then, what I am asking is if there will be a difference in wiring each subs coils in series, then paralleling the subs together verses paralleling each coils subs then series wiring them together.

The end results in terms of resting impedance is the same.

[Triticum Agricolam]

The electrical side of things isn't my area of expertise, but whether you wire series-parallel or parallel-series the result should be the same.

If you are rising from .5 ohms up to 3.8 I suspect you have quite a bit of compression, either port or power compression. Have you tried testing at half power to see what your rise is at that level of output? I'd be curious to know.

[all4spl]

Well the subs are literally brand new and VERY VERY stiff, the enclosure and power has all remained constant the only change is the subs and the impedance of the coils. Sundown dual 2ohm subs to DDs dual .5ohm subs.

The sundowns rise from .5 to 1.8 @ 51Hz, the DDs go from .5 to 3.8 @ 51Hz. So power is down a lot, score is too, but just trying to figure out if the wiring could be effecting it at all. If the DDs need time to break in, then not sure if I am going to use them at finals this year but I am exploring all the options.

[ToNasty]

That sub is going to stay stiff. I have a year old dd3515 sc. That mt buddy has now. It's still stiff as shit.

[ShadeTreeMechanic]

I believe that the ts parameters are measured with coils in parallel. Coils in series the inductance doubles. Coils in parallel the inductance is halved. Over a single coil that is. More inductance in the load requires more capacitance in the amp output to help keep voltage vs current phase reasonable. Maybe Tony D could tell us how this affects the impedance rise.

[all4spl]

DD has recommended to parallel the coils then series the subs together, so I am going to try that today after work and see if it tests differently.