Dynamatted my drivers today, should I do the PRs too?

pietsch288

Is there a thread "for dummies" that I can follow/research. I love the rt3000p's and the cs1000p for what they are... but that doesn't mean they can't get better. I never imagined that the 3000's would be such a huge step forward over the other speakers I have had in the past. So if I can make them better I'm all for it. thanks rich

pietsch288

or maybe DHS speaker service??

F1nut

There are a lot of threads on crossover upgrades, but I don't recall seeing one for your speakers. Basically, it involves replacing the caps and resistors with ones of higher quality. The upgrades will make a vast improvement in the sound. If you're not up for doing them yourself, you might want to talk with member VR3.

What is DHS speaker service?

westmassguy

F1nut wrote: »

There are a lot of threads on crossover upgrades, but I don't recall seeing one for your speakers. Basically, it involves replacing the caps and resistors with ones of higher quality. The upgrades will make a vast improvement in the sound. If you're not up for doing them yourself, you might want to talk with member VR3.

What is DHS speaker service?

That would be me F1nut

pietsch288

ok westmassguy, what are guys doing to the rt3000p's to improve sound, I assume I have to mod the tops and the bottoms. I would also like to mod the cs1000p to match.

DHS speaker service....Is what I found when I goggled(polk xover mod). Apparently he is a member here/has a web site dedicated to moding xovers/has a ebay "buy it now" service for mods. I guess I figured because he was a member everybody would know who he was. thanks for the help.....rich

westmassguy

pietsch288 wrote: »

ok westmassguy, what are guys doing to the rt3000p's to improve sound, I assume I have to mod the tops and the bottoms. I would also like to mod the cs1000p to match.

DHS speaker service....Is what I found when I goggled(polk xover mod). Apparently he is a member here/has a web site dedicated to moding xovers/has a ebay "buy it now" service for mods. I guess I figured because he was a member everybody would know who he was. thanks for the help.....rich

Rich, I already replied to your email this morning. Check your junk mail folder.

F1nut

westmassguy wrote: »

That would be me F1nut

So it is, thanks!

leftwinger57

explain this to me .I know Dynamat is a sound deadening material mostly used in car interiors.Now I do not hear any rattles,scraping ,just movement of the surrounds themselves w/ my 2b s so if none of the usual suspects are noticed when and why would you do this. Forget about x-overs and cables for a moment, just this stuff.

westmassguy

leftwinger57 wrote: »

explain this to me .I know Dynamat is a sound deadening material mostly used in car interiors.Now I do not hear any rattles,scraping ,just movement of the surrounds themselves w/ my 2b s so if none of the usual suspects are noticed when and why would you do this. Forget about x-overs and cables for a moment, just this stuff.

In this application, Dynamat adds mass to the light weight, stamped steel basket frames Polk used. Light weight steel can "ring" or resonate when exposed to certain frequencies. When these frequencies excite the frame, within the range of human hearing, it can make it's way out through the cone or passive radiator, and distort or smear the image. Pull one of your woofers and tap on it. You'll hear a distinct ringing sound. Once the Dynamat is applied, the added mass mitigates the ringing. You can't eliminate it completely, without re-designing the entire woofer. The Dynamat reduces it to a level that most people cannot hear, or is masked by the music.

ozzy44

I understand where adding mass to the speaker basket will subdue the 'ringing' of the driver in FREE air. However, once the driver is securely mounted, the ringing is gone. I proved this by pressing the driver against the baffle while tapping on the basket......voila, NO RINGING! I fail to understand how adding Dynamat to a MOUNTED driver will improve the sound quality!

Gardenstater

If you pressed a bell against a particle board box with a thin foam rubber gasket around the rim using the palm of your hand it wouldn't sound the same (assuming you could still actuate the clapper) because you have lowered the resonant frequency and you are dampening the vibrations. You are coupling it to the masses of the particle board and your body. Now put some constrained layer dampening material on the bell like Dynamat Xtreme and you will hear that it sounds even more muted, even if you were clamping it somehow without your hand.

F1nut

ozzy44 wrote: »

I understand where adding mass to the speaker basket will subdue the 'ringing' of the driver in FREE air. However, once the driver is securely mounted, the ringing is gone. I proved this by pressing the driver against the baffle while tapping on the basket......voila, NO RINGING! I fail to understand how adding Dynamat to a MOUNTED driver will improve the sound quality!

One problem with your experiment, there are no hands pressing on the rear of the driver baskets inside your speakers.

The soundwaves inside a speaker will cause a thin stamped steel basket to vibrate. That vibration creates distortion. Damping the basket helps to clean up the sound reaching your ears. It's pretty simple stuff really.

Most drivers today have cast aluminum baskets for a very good reason, they don't ring.

gp4jesus

Ordinary pipe wrap. Cheap, VERY easy to get and use. I confess Dynamat, SecondSkin, and similar/like products can’t be beat to cover larger surfaces.

Wrap it around your magnet shields*, on your drivers’ frame spokes, and most any other semi-shinny/shinny surface does all kinds of good.
*RTi A series shields ring like bells

Gardenstater

gp4jesus wrote: »

Ordinary pipe wrap. Cheap, VERY easy to get and use. I confess Dynamat, SecondSkin, and similar/like products can’t be beat to cover larger surfaces.

Wrap it around your magnet shields*, on your drivers’ frame spokes, and most any other semi-shinny/shinny surface does all kinds of good.
*RTi A series shields ring like bells

A future mod I am planning on is to put some Armacell on the inside of the basket spokes in my MW drivers, to see if there is any audible improvement/change at all. In theory it might help to dampen some of the internal acoustic back wave reflections and reduce the amount coming back at the cones from behind.

gp4jesus

Gardenstater wrote: »

A future mod I am planning on is to put some Armacell on the inside of the basket spokes in my MW drivers…

I had not considered some sound WILL reflect from the inside of the “spokes.” I’ve put it the outside.

Gardenstater wrote: »

…to see if there is any audible improvement/change at all. In theory it might help to dampen some of the internal acoustic back wave reflections and reduce the amount coming back at the cones from behind.

The front side of drivers should be the only source of sound. This kinda parallels diffraction pads.

I’m gonna do this the next time I open a speaker. I have two more surround speakers to prep for the day I expand to 7 channels. Also one of my towers’ internals needs some attention - add that to the process.

Gardenstater

Yep lets both try it. Seems like a pretty easy mod to check out I got the idea from reading a patent of a Vandersteen midrange driver.

gp4jesus

Thanks so much for voicing this simple idea that will help better manage those “pesky” upper mid range frequencies something the RTi/RTi A series need all they can get. Sorry for my long windedness too

Do ya think you’ll get to one channel by early pm, July 6th lol? Have you or do you plan to Hurricane nut (H-nut) the driver’s screw holes? See Jesse’s “Having fun RTi A series speakers” thread for details.

At the moment I have five working channels but in the middle of a ginormous backyard project. I have two pairs of surrounds - one pair free to mod at my leisure. Part of my surround speaker mod is removing the XO and re-wiring to bi-amp them. Another is H-nutting* the driver screw holes of any closure I open. I limit this mod* to any driver handling the mid range and below.

Side note: for those hesitant. I learned the value of simple mods like this when I Armacell-ed one speaker at a time and in between doing each speaker, listened to both, one at a time w/tweets disconnected*. Cranked up, I heard loud, metallic, non-musical sounds coming from the unmodified speaker.
*the RTi/RTi A series speaker make these easy to do. I’m sure other makes & models can too

See ya soon George

Gardenstater

gp4jesus wrote: »

Thanks so much for voicing this simple idea that will help better manage those “pesky” upper mid range frequencies something the RTi/RTi A series need all they can get. Sorry for my long windedness too

Do ya think you’ll get to one channel by early pm, July 6th lol? Have you or do you plan to Hurricane nut (H-nut) the driver’s screw holes? See Jesse’s “Having fun RTi A series speakers” thread for details.

At the moment I have five working channels but in the middle of a ginormous backyard project. I have two pairs of surrounds - one pair free to mod at my leisure. Part of my surround speaker mod is removing the XO and re-wiring to bi-amp them. Another is H-nutting* the driver screw holes of any closure I open. I limit this mod* to any driver handling the mid range and below.

Side note: for those hesitant. I learned the value of simple mods like this when I Armacell-ed one speaker at a time and in between doing each speaker, listened to both, one at a time w/tweets disconnected*. Cranked up, I heard loud, metallic, non-musical sounds coming from the unmodified speaker.
*the RTi/RTi A series speaker make these easy to do. I’m sure other makes & models can too

See ya soon George

Roger that Tony. I think I can see my way to remove an MW and try the Armacell mod before you come. Should be pretty easy. I'm rockin' the Rob's Rings (xschop) and they are permanently JB weld epoxied into my speakers. They kick **** and are an even bigger improvement than Dynamat.

gp4jesus

Gardenstater wrote: »

Roger that Tony. I think I can see my way to remove an MW and try the Armacell mod before you come. Should be pretty easy. I'm rockin' the Rob's Rings (xschop) and they are permanently JB weld epoxied into my speakers. They kick **** and are an even bigger improvement than Dynamat.

I’d love to know more about “Rob’s rings.” Save save the details for the visit. I’m curious - shouldn’t his 6.5” rings fit* any Polk 6.5” driver? Meanwhile I’ll try to take some very careful measurements. If so*, he may have another customer for 4 to start and perhaps 4 more later on.

Concerning the Armacell mod: I’m FAR more interested that YOU can hear a diff/improvement comparing one modded to the other un-modded. I encourage you to complete that on your schedule, not mine. You hearing a diff is good enough to prompt me to follow suit in due course.

However if you don’t complete the second before the 6th, at 63 I hope, but may not hear a diff as my hear isn’t what was even 2-3 years ago. Back in the 80s I had been to a few LOUD concerts (Rush, 10th row center at the Garden) numerous jam sessions, and a one round, unprotected direct exposure to an Army tank’s main gun blast. A guest on the range told me: estimated at 186 dB.

That’s it for now. The rain stopped gotta go. Can’t wait for the 6th.

Tony

gp4jesus

To anyone reading this: Armacell your drivers’ frame surface that faces the backside of the cone - it’s worth the trouble.

He modded one speaker and had me listen w/out saying which was which: I could hear the difference.

Gardenstater

Tony I wish I had done both of them for when you were here. I have been enjoying this latest mod for almost a month now and it is a huge bang for the buck. I know everyone has heard this before but I am hearing things in albums I know and love and have an intense audio memory of, that I never heard before!! I hope others will try it and report back. I posted pics and details in the other thread "What did you do to your stereo rig today?".

gp4jesus

Pour fresh cup of Joe or a tall cold one while read my long-winded reply…

Simple: as we discussed in July, like the Diff pads for your tweets, your mid drivers are much closer to being the single midrange sound source for your mid frequencies resulting in less smearing of the image. Can’t wait to do the same to my speakers, even the surrounds!

Right now my honey-do list is too long and compelling. That and my shop space isn’t ready to tackle any tweak projects.

Sorry for the de-rail: I just PU another Rotel 981 at about 30% less than typical. Now that I have a spare*, gonna follow a DIYaudio thread that guides most any reader, handy w/soldering iron, through cap refreshing, etc** to restore and upgrade its SQ. One subscriber raved about the SQ improvements.
*I will use it, when I expand to 7 channels
**not limited to just caps.

Sorry for the 2nd de-rail: A couple of my “tweaker” friends w/better ears than I consider this…

“GRP Live in Session”
https://m.youtube.com/watch?v=985KYeLenBo

https://m.youtube.com/watch?v=pUpvhWtKK1U

…one of the best Live contemporary jazz they’ve ever heard. Give them a listen on YT though it SQ doesn’t do them justice. If it stirs you, the CD* or LP* is worth the $. Two tracks in particular: “Morning Dance” and “Reverend Lee.” (RL) RL”s vocals right near the can test or tax your mids. Years ago this same track, while demo-ing speakers, uncovered that one channel’s polarity was reversed!
* I have both plus DVD downloaded from a VCR tape.

Keep plugging away. Tony

Tony M

I got goose bumps from head to toe with this one about midway through. The ending was a little shrill but still...She can vocalize and the band IS tight.
https://youtu.be/pUpvhWtKK1U

gp4jesus

I’m really glad you like it.

I’m also sorry I forgot to mention I was surprised to learn the tracks on these YT vids have parts edited OFF the CD* & LP. And I hafta make 2 small corrections…
* I’ve listened to many times over the last 35 years

“… RL’s vocals right near the end can test or tax your speakers’ mid range.” as Tony M attested.

That speaker demo was in a showroom in which the reversed speaker polarity was discovered.

plastic_avatar

Drenis wrote: »

This is how you dynamat PRs. Once you do that and tap the basket, you become a believer in this mod. It applies across the board with the MW's as well.

Ollllld thread, I know.

What is meant by tapping the basket?

xschop

westmassguy wrote: »

pietsch288 wrote: »

I assume I should "mat" the 6"ers in the satalite speakers as well as the 8"ers in the sub? rich

Any woofer or passive radiator with a light weight, stamped steel basket frame will theoretically benefit from the Dynamat

This is bond. I've recently done a set of TSi drivers and it took out the tinny, ring sound as well.
While you're at it, you should consider doing @Gardenstater's foam basket mod. Very worthwhile improvement in midrange.

https://forum.polkaudio.com/discussion/195562/must-try-mod-foam-inside-the-stamped-steel-baskets-yes/p1

gp4jesus

Sorry for the long post

plastic_avatar wrote: »

What is meant by tapping the basket?

The “basket” is a midrange’s or woofer’s frame. Some will have cast aluminum frames. Tap it w/screwdriver or small wrench, you may hear it ring - more likely w/stamped steel. Home theater speakers will have shielded magnets that, IME, rings loudly just like a bell!

Regardless, covering the outer basket surfaces damps ringing. It also drastically reduces reflected midrange frequencies from ~500hz on up. Covering the magnet*, especially if shielded, takes the above a bit further.
*do not cover any magnet vent holes

Thanks to xschop for posting a link to this other thread…

https://forum.polkaudio.com/discussion/195562/must-try-mod-foam-inside-the-stamped-steel-baskets-yes/p1

…sings the merits of applying the same to the part of basket that faces the driver’s backside further reducing reflected sound.

I’ve cited this as a very easy & equally CHEAP tweak. I posted in that other thread “before” and “after” pics of a shielded Polk mid/woofer from 5 years ago.

Tony

plastic_avatar

I eat long posts for breakfast. It's my favorite way to start the day

Tapping = Ohhhhh. I was thinking like tapping an engine for re-threading spark plugs holes or something. Now I understand

I'll get foam and tape and mat this week. And caulk. I'll disassemble my Monitors and do the basket mods to them, too!

Thank you guys for the follow-up!

xschop

F1nut wrote: »

Upgrading the components on your crossovers are a must do.

Not if you're running a 15wpc Crown amp.😂

plastic_avatar

Drenis wrote: »

This is how you dynamat PR's:

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Your attention to detail and precision is amazing.

How did you cut the matting to allow dhaping like that?