Batting question

Olivesaxer

Hello - I have recently started to tear into my monitor 7, series 2's.

Tweeters on order, woofers and PR's dynamatted, box locktited, and a couple of rings of moretite around all the seals.

All of these things have been done with close reference to the mods that Polk Folk are doing here. So thank you all.

I also have only done these mods on one speaker (so far) while keeping the other stock so that I can get some good comparison curves to share with the masses. (Once I get the readings off of the two, I will complete the mods on the other speaker as well).

My question has to do with the batting material in the box. Mine simply had what looks like an upholstery batting sheet rolled up tightly and stuffed behind the tweeter. The images that I see online of mods have more batting than my speakers did, and have it positioned behind the tweeter and the woofer. What is necessary? What is preferred?

Thanks in advance.

-Patrick

F1nut

Remove the Mortite, horrible stuff. Get some real gasket material from Parts Express.

Jaybeez

F1nut wrote: »

Remove the Mortite, horrible stuff. Get some real gasket material from Parts Express.

I knew this was coming before I even opened the thread!

Olivesaxer

As promised - here are the response curves of an unmodified Monitor 7 vs a modified Monitor 7 (with the modifications described above). For comparison, the last image is a SRS 3.1TL unmodified.

This was performed in the same room in roughly the same position with a Pink Noise generator.

Thanks.

Unmodified Monitor 7 Series 2:


Modified Monitor 7 Series 2:


SRS 3.1TL (Unmodified):

tonyp063

The batting should be rolled up & stuffed behind the mid-woofer. Do not get it behind the passive or tweeter.

F1nut

In the original Monitor 7 and Series 2 the polyfill should be stuffed up behind the tweeter and mid-driver.

Don't forget to get rid of the Mortite.

tonyp063

Thanks Jesse, I stand corrected. For some reason I thought it was mid-woofer only.

Olivesaxer

F1nut wrote: »

Remove the Mortite, horrible stuff. Get some real gasket material from Parts Express.

What would you recommend? After redoing #2 last night, it is leaking like crazy, so yes, I'm very interested in not having to work with Mortite.

CH46E

Olivesaxer wrote: »

F1nut wrote: »

Remove the Mortite, horrible stuff. Get some real gasket material from Parts Express.

What would you recommend? After redoing #2 last night, it is leaking like crazy, so yes, I'm very interested in not having to work with Mortite.

I just ordered some of this a few days ago. Seems to have great reviews. Sorry its out of stock now but should replace the Mortite right?

CH46E

Oliver, would you happen to have any pics of the dynomat you put on the drivers? Im waiting on a few more parts and will be doing my 12b. Would like to do everything at once.

boston1450

Is that the same stuff as Armacell they sell at HDepot

pitdogg2

boston1450 wrote: »

Is that the same stuff as Armacell they sell at HDepot

no it doesn't compress as easily as the Armacell. I have used both.

michaeljhsda2

boston1450 wrote: »

Is that the same stuff as Armacell they sell at HDepot

I don't think it's the exact same stuff, but it's similar.

Olivesaxer

Thanks - this is awesome.

Regarding batting - Speaker 2 was again stuffed with a rolled up sheet of batting only behind the tweeter. The tightness of the factory batting indicates it was only behind one driver (either the tweeter or the woofer). If as some of you suggest, I should put batting behind both the tweeter and the woofer, I will have to go get more.

Is there any precedent to this - or does it matter?

Thanks in advance.

boston1450

I tacked mine up so it wouldnt fall down with small staple gun. Others may chime in with better thoughts

jmur

I also have a couple questions about batting.

I have a pair of Monitor 10 with a date of April 1 1977 that is stuffed with batting from top to bottom. Should I change that to be like what you recommend above?

I recently picked up a pair of RTA-12B and they also have batting the length of the speaker, but it's a single sheet that's not tight and has a slit in the center for cables to go through. Leave this as is?

I also have Monitor 7C and 7 Series 2 and they both have the batting like you describe. I think it's against the upper part of the MW drivers to hold it in place so it's behind the top part of the MW drivers.

Thanks

F1nut

It should never be behind the passive radiator.

Unknown

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Unknown

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mhardy6647

n/a

Braddles63

I have several vintage Polk models and have followed the no batting behind the PR rule but when i picked up some Monitor 7A's they were full top to bottom with batting. When i did the regular upgrades i left the batting out of the bottom of the box but found them too bass heavy and boomy. So i put it all back and this improved the balance.

HzTweaker

boston1450 wrote: »

I tacked mine up so it wouldnt fall down with small staple gun. Others may chime in with better thoughts

Try hot glue.

F1nut

Staples work much better and you only need a few.

None of the vintage Polk speakers ever had battling behind the PR's. If you've got boom a few possibilities are the speakers are too close to the back wall, your power source is a bad match, your room sucks or there's an air leak.