Passive push test...

hochpt21

I've seen various threads on this but don't remember what the outcome should be.

The mid woofers are supposed to slowly return...correct? Three to five seconds?

I just tested my 2a studios and the mid woofers return immediately. Do I have a leak? If so...how much SQ is being compromised?

hochpt21

Is there an extreme loss in SQ?

I'm hoping to get the xovers done at some point so I'll have to address it then.

F1nut

You push the PR in and HOLD it in while watching the mid-drivers, which will pop out, then start to slowly recede. They do not stay all the way out. You count how long it takes them to recede. 2 to 3 seconds is average, 5 seconds is highly unlikely.

nooshinjohn

I had a 4 to 5 second leakdown on a set of 1.2TL's, but I used the same count method as Nbrowser did.

nooshinjohn

nbrowser wrote: »

nooshinjohn wrote: »

I had a 4 to 5 second leakdown on a set of 1.2TL's, but I used the same count method as Nbrowser did.

1 one thousand, 2 one thousand, 3 one thousand...not scientifically accurate but...close-ish.

Yep... worked for hide and seek too.

westmassguy

nbrowser wrote: »

F1nut wrote: »

5 seconds is highly unlikely.

hrm my Monitor 5's last a good 5 count before the MW goes all the way back, my SDA 2s, about 4 seconds. Then again I don't use a stopwatch so times are approximate...lol

hotchp, yeah it'll be a loss of SQ as the MWs aren't effectively coupled to the passive with a good sealed cabinet, bass obviously is suffering.

Makes sense for the Monitors 5s, they only have a single woofer. Each woofer adds a little more leakage. The spiders are porous, and the dust caps are screen type.

Schurkey

...and when you release the PR, the woofer cones will suck into the cabinet. This requires approximately the same amount of "return time" as when you pushed-in the PR.

hochpt21

F1nut wrote: »

You push the PR in and HOLD it in while watching the mid-drivers, which will pop out, then start to slowly recede. They do not stay all the way out. You count how long it takes them to recede. 2 to 3 seconds is average, 5 seconds is highly unlikely.

I'm an idiot. I've tried this a bunch and was just disappointed because they returned immediately.

Even though you all capped HOLD I didn't catch on until recently re-reading it.

My seal is fine on both speakers.

I'm an idiot.

voltz

I did that same for a few times and had my scratching my head cause I used loctite powergrab around all sides and corners inside. I felt the same way when I figured out my mistake.

boston1450

hochpt21 wrote: »

F1nut wrote: »

You push the PR in and HOLD it in while watching the mid-drivers, which will pop out, then start to slowly recede. They do not stay all the way out. You count how long it takes them to recede. 2 to 3 seconds is average, 5 seconds is highly unlikely.

I'm an idiot. I've tried this a bunch and was just disappointed because they returned immediately.

Even though you all capped HOLD I didn't catch on until recently re-reading it.

My seal is fine on both speakers.

I'm an idiot.

I bet there are people out there that have owned them for years & never done this.

PolkieMan

The right one holds much better than the left. So where are most leaks found around the subs?

hochpt21

PolkieMan wrote: »

The right one holds much better than the left. So where are most leaks found around the subs?

I'm obviously not the expert, but I would venture to say if one is holding better than the other, the leak is the seal on the driver that is not holding. Do you have new gaskets/armacell and/or hurricane nuts/larry's rings?

PolkieMan

No it's all original except for the tweeters and the crossovers. I did suspect something as my 1C's seem to have more bass. I took one screw out and you can feel and hear the air coming out of the hole if you hold your ear up about two inches from it. I ordered a stethoscope on Ebay they are cheap about $5. These are getting ready to have their 25th anniversary in my home in July.

hochpt21

Congrats on the anniversary

Take the drivers out, buy some cheap Armacell from Home Depot and replace the gaskets. Get some hurricane nuts or Larry's rings and I bet you'll be set. While the drivers are out, throw some dynamat on the baskets and glue the magnets.

Cheap but effective modifications.

leftwinger57

Same advice here. When some said their mid woofer return was over 5 seconds I'd say that they are stretching things a bit w/ their times. Once one does seal the cabinets,install either Larry's Rings or H-Nuts and very important if your old gaskets are questionable make new ones and the effect was that dramatic. Certain mechanical mods that one can do very easily does pay off and this opinion is coming from me, the one who refused to believe mods could improve on my wonderful bone stock 2Bs. I was proven wrong,fully admit it and was glad to do the mods.
Dynamat Extreme-free, Black Hole-5-$12 C/L, Larry's Rings-$60--Armacell-$8 and Liquid Nails I think was $6 for a large tube.

PolkieMan

Thanks I have got some work to do I just need to extra time. But I gather that it's the driver seals that are the most leak prone. Has anyone had a reason to do the terminal cups because of a leak?

teekay0007

PolkieMan wrote: »

Has anyone had a reason to do the terminal cups because of a leak?

Didn't need a reason, PolkieMan. Just took care of it while I was in there and cutting away on the Armaflex strips...easy peasy! However, you should hold off on doing it until you have H-nuts w/screws or Larry's rings ready to go, so you can fasten them down tight for a good seal. Otherwise, you're likely to strip out your wood screws.

While you're in there, you should also 1) put a bead of Loctite Power Grab around all your drivers' magnets and in any of the cabinet seams if necessary, 2) apply Dynamat Xtreme to your drivers' and PRs' baskets and 3) maybe put some strips of Black Hole 5 or Sonic Barrier (acoustic foam) behind your drivers.

Then, finish them off with some nice spikes and you're there. Heck, you've already done the biggest part of the whole SDA upgrade process in rebuilding your crossovers (w/Sonic caps, Mills resistors and Gimpod's boards) and upgrading the tweeters.

There's lots of sonic gain yet to be had there, now get after it!

PolkieMan

Yea I need the time off, not to complain a lot of Texans, are out of work.