sub break-in period

Hey all

I just replaced my 3 10" 8000 series MTX with 3 new ones and was wondering how long they usually take to break-in. I bought the last set 3 months, used from a friend, and they hit extremely hard compared to these new ones. The box is sealed and airtight, and the subs have a good bead of silicone applied.

Exact same sub only these are new.

The just aren't hitting hard or holding the long hits.

I use a 150 amp alt and an SP1700 battery. 14.4 volts always.

Anyone????

The only difference is in the settings after the sub has broken in and become more flexible.  Readjust the gain, crossover and anything else you can think of to tinker with.  It's pretty normal (for a DIY install) to do a system tweak a few times anyway.  The hardest part is to keep yourself from blasting a new sub to full power, right out of the box.  When setting gain on the amp by ear, that's exactly what you have to do.  That's why a recheck of gain setting is in order after a week.  If you're setting gain with a DMM, you can do that with the sub unhooked and save the trauma to the new speaker...and get a more accurate setting.

(If you're setting gain with a DMM, you can do that with the sub unhooked and save the trauma to the new speaker...and get a more accurate setting.)

Is that DMM a digital multimeter? How would I use it to check gain? That sounds like a great idea.

<Break in period is 20 hours playing at low volume.>

I played them pretty hard, especially while setting gain. Do you think that could have already damaged them? 

No, you wouldn't have damaged them doing that.  Playing them hard at clipping level will do the damage.  You just might not have gotten an accurate enough "measurement by ear" because setting gain is listening for distortion, and you might not hear it as well with a new sub.  As far as DMM = digital multimeter, yes.  Read AC volts at the speaker terminals of the amp, with sub unhooked, HU at max clean volume, crossover at full, bass boost off...you will be reading the voltage that you have figured using Ohm's Law as it applies to the power you want to send to the speaker(s) at the ohm resistance on the amp.

A test tone is necessary, played through the CD unit.  You can use 50 Hz for subs, or get the highest reading by trying several freqs in the sub's range.  You can't get a steady or accurate reading by playing music.

E=(PXR)^.5  which is to say:  voltage in AC volts = the square root of (watts of power times the ohm resistance).  You can post your particulars here for some verification of numbers if you want.

Then having set the gain with the meter, you won't have to rely on  hearing distortion at full volume, which can be very difficult to do.  A new sub then can be played at reasonable levels for several hours before show-off time starts.

Excellent! I learned something new today :)