SRS 1.2TL with Blackhole 5 Damper
Comments
-
These are very similar to what I use: http://www.amazon.com/Pachi-Paradice-EMT-UTILITY-SCISSORS/dp/B000S96A2A/ref=sr_1_3?s=hi&ie=UTF8&qid=1293722014&sr=1-3
Face -
The picture makes it look as if the edges are soft and it has a soft plastic glow to them. Are they really sharp? (Pics can be deceiving) My scissors are sharp sharp and are of that length. Since we are talking about cutting through a sponge of over an inch of thickness, and this stuff is thick, the cutting may not be as "easy" as cutting through carpet. Know what I mean?Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
That may work, but I could see it making a mess.PolkMaster1 wrote: »Face -
I read somewhere that they used a saw to cut through the BH5 with good results. Cant remember where I read it. Again, I have not tried this, nor do I have access to carpentry items - most of us apartment dwellers do not have such things lying around, unless we do carpentry for a living. I am not one of them.
The scissors I use look almost exactly like those pictured in the link. They still don't cut through like butter, but it's a lot easier than anything else I've used.PolkMaster1 wrote: »Face -
The picture makes it look as if the edges are soft and it has a soft plastic glow to them. Are they really sharp? (Pics can be deceiving) My scissors are sharp sharp and are of that length. Since we are talking about cutting through a sponge of over an inch of thickness, and this stuff is thick, the cutting may not be as "easy" as cutting through carpet. Know what I mean?"He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche -
Face -
This is what I used to cut the BH5. And they are sharp.
http://www.staples.com/Westcott-KleenEarth-8-Scissors-with-Microban-Straight-Handle/product_816195?cmArea=SEARCH
Isn't it good to know that Polkies are earth friendly? :biggrin:Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
The other scissors are better as they offer leverage, those silly green things would be better off in your kitchen than utility/tool chest. :biggrin:"He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
-
We can ask what ToolForLife used to cut his BH5. Just a note about my experience with the cutting process with the tools I used, for peices bigger than an inch - expect to go over cutting the area with a knife and scissors a couple of times at least.
Your milage may vary with the tools you have at your disposal.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
I bought them at least a year ago, before the BH5 was ever a thought in my head. I can tell you those things are sharp and their edges are thick!!!
With the edge angled scissors, yeah, I can see where they offer leverage in the angle handles. The key is that they have to be sharp and sturdy. The edges look too thin in that picture which may be a liablilty for the BH5 project. Cant say for certian because I dont have them in my hands. Yours may be sharp and thick though.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
I think I'm spending more time on this forum than actually evaluating the speakers...Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
PolkMaster1 wrote: »And here are the drivers... all alone and distant from its home....
How did you get them to shine like that,windex?PolkAudioClyde -
I haven't seen the material you are having to cut but I've cut a lot of bat insulation with a utility knife. I lay a board along the cut line and press down with my knee making the insulation very thin and it's easy to cut.
Just a suggestion that might help.
Were you not happy with the speakers as they come from the factory?
Very interesting thread thanks for posting.TO ERR IS HUMAN. TO FORGIVE IS CANINE. -
I know most of you probably have a Sharpie with or near your workplace, ready to identify components as you put a project together. My 2nd best marking implement is a SILVER Sharpie, which shows up GREAT in the case of black or any other dark colors..
My third is the cheepie etching tool, that runs on a single AA battery, and will allow you to (not very elegantly, mind you) mark on any hard surface..
Just throwing my .02 in there..
So, has there yet been a consensus of which dampening products is predominant at this time? I just happen to be rebuilding a pair of CV D-9's that I purchased back in '82, and used for 10 years with a good ol' Peavey PA-400.
The 15" bass driver had crumbling rubber surrounds, which prompted me to give the entire unit a makeover, from the grille to the rear connectors..''
I'm not ready at this moment for the dampening material, but it's a comin' up soon, so any push in the right direction would be appreciated!
So far, it's been new 15" drivers, replaced the rear spring connectors with 5-way banana cup-mounted connectors, which had plenty of room to add a 1/4" TS for future possible wiring needs.
Right now, I'm installing the 4" "PrecisionPort's" from psp-inc, just "filling in the holes" from the cardboard tubes that came from the OEM. The new driver numbers made the new dual 4" ports 13.5" (including the flares internal/external).
[ TIP O' THE DAY FROM AN OL' FOSSIL.. ]
If you are looking for "surround material" for a circular speaker up to 15", example, my D-9's have a 1" x .25" deep route around the cutout for the 15" driver.
[ ENTER WALMART ]
Walmart has a "placemat," originally made for the dining room table. It is a 1/8"-3/32" woven mat with very thin concentric circles. It is advertised, and it truly is EXACTLY 15" round. The concentric circles are roughly .25" each.
So after removing the 20 year old foam sheet that was originally placed there, I carefully cut the last 4 "circles" off of the placemat, and voila! a PERFECT surround damper.
Oh, and I still have the LAST 14" sitting here, so I can "do" one of the other four speakers or "crossover-in-a-cup" ( I simply refuse to make the obvious joke of "3-way, one cup"). The cost of the mat? $2 I have seen them at Walmart, Meijers, and Biggs in my area (can't tell I'm a late niter, can you?).
I've got a few mid's to swap out and give a listen.. The CV D-9's run two different sized speakers in parallel off the same mid-port of the crossover, but each has a slightly different aural range.
Since CV wanted to play around with a parallel universe, I'm going to throw in a ribbon in parallel with the provided tweet, and using an L-Pad to adjust, see if I can get a good musical "feel" by incorporating a ribbon that goes up to 40kHz.. To the uninitiated, the frequencies out of hearing range (18k-20k or so), vibrate the bone behind the ear, which is the "feel" you get when you hear glass break. It's just a "what-if." There's actually plenty of space for it on the frontside, though I'm also going to try it from the rear - again, just "playin' around" and seeing what happens..
My test setup is an old Crown 402 coupled with a CD/CD-SA player and some seriously crazy sonics from Telarc.
Cheers!
Rick -
FYI -
Just to give everyone an update and some sort of closure, I decided that the polyfil used in combination with the BH5 sounds better in both speakers compared to the BH5 without polyfil.
Now... the next question is pad the sides, or not to pad the sides, using BH5, Sonic Barrier, or no barrier.
Stay tuned....Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
I have found dampening the sides of the cabinet has done more than the back ever had.
I a stripe pattern instead of solid covering. Especially in the area near the drivers and PR.
Both of my SDA2's cabinets got a little to resonant at certain frequencies. I would say somewhere around a low E that gives the cabinet a buzz. I used Dynamat on the back and sides and never heard it again.
I had Monitor 10's that got buzzy as well but it was much lower in the speakers range. I did more experimentation with this speaker and found just placing an X pattern on the sides and back eliminated the resonance. -
I'm wondering whether or not a mod of this type is only beneficial in the case of speakers with cabinets on the larger side. I'm about to kick off a project to do up an uber pair of 4.1TL's, where I'm throwing every mod I know of at them. Do we see an application for this dampening in CRS+ cabinets, particularly where the rear of the cabinet is the opening for the passive radiator?Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
-
I'm wondering whether or not a mod of this type is only beneficial in the case of speakers with cabinets on the larger side.
That is a good question which I have pondered after the completion (?) of the project with these set of speakers. Would smaller speakers, such as those that are bookshelf or rear channel speakers would benefit or be hindered by BH5? Since I do not have any experience with damping smaller speakers, I can only speak to the point of which would make logical sense.
If we assume that Polyfil is used pretty much in every speaker that is made for indoor home audio (at least using the Polk Audio speaker line as a model speaker), smaller speakers such as bookshelf and rear channel speakers move sound, in a smaller volume compared to the full-range floor standing speakers. This is based on size of cabinet, type of drivers, and quantity of drivers. Since the cabinet would be on the small side, not as much air would be moved (or displaced) as a big cabinet would. Factor in that you would have not as much room to work with inside such a small cabinet compared to the big floor standing speakers. I believe using a thick material such as BH5 would do more harm than good for the small speakers. I would say that if someone wanted to add damping material to their small speakers, it may be best to use an alternative competitor such as Sonic Barrier, where they sell damping materials in thickness of 0.5, 0.75, and 1 inch material. This may be better suited for the smaller speakers compared to BH5's damping thickness at 1.35 inches.
Hopefully, someone may find this to be good sound advice and would post their experience.
PM1Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
PolkMaster1 I completely agree with your assessment, as there is less internal volume to play with on normal bookshelf speakers.
But CRS's are not normal bookshelf speakers. I would guess that CRS's could push nearly as much air as say a SDA2b, although there internal volume is smaller they do have the same compliment of drivers but a 10" Passive compared to the 12" Passive on 2b's.
So do you think BH5 would help in that situation? Or would you think a thinner material like SB or Dynamat would be sufficient? -
The other problem with CRS+'s, remember, is that the passive radiator is on the rear of the cabinet. Correct me if I'm wrong, but the application of BH5 described here is to the rear wall of the cabinet only. Specifically for CRS+'s, this is not easily accomplished, and definitely not doable behind both drivers. You could, possibly, apply the BH5 to portion of the rear cabinet that doesn't include the opening for the PR, but then one of the drivers will have the BH5 behind it and the other won't (offhand I don't recall if it's the dimensional or stereo driver that is back to back with the PR). It's not sounding to me like this mod is particularly advisable specifically for the CRS+ cabinet, but I continue to be interested in hearing advice from the myriad of people here who are far smarter than me!Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
-
PolkMaster1 I completely agree with your assessment, as there is less internal volume to play with on normal bookshelf speakers.
But CRS's are not normal bookshelf speakers. I would guess that CRS's could push nearly as much air as say a SDA2b, although there internal volume is smaller they do have the same compliment of drivers but a 10" Passive compared to the 12" Passive on 2b's.
So do you think BH5 would help in that situation? Or would you think a thinner material like SB or Dynamat would be sufficient?
Hello Joe.
I do not have personal experience with the CRS (or the CRS+) speakers. I looked them up and have mixed feelings about damping this speaker. It is roughly the width and half the depth of a standard size pillow. The radiator in the back makes it a bit confusing on how best to go about damping it. If you are serious about damping, I would recommendation the following:
1. Contact PA Customer Service. Tell them you plan to add additional damper to the speaker and see what they say on where to damp, the daming you plan to use, and the thickness of the damping material you plan to use (such as BH5, Sonic Barrier, or another type of damping material). If that fails or for additional advice, I offer the following:
2. Take a look inside the speaker and see where the polyfill is layed out. Ask PA where the polyfill should be laid out for best results. Polyfill can be moved around and shifted in a speaker over time, which can cause diminishing results. Once you have the polyfill layout information, use this as a guide for where you plan to dampen.
3. Do not dampen the PR area. This statement is based on the recommendations that were given to me by PA and other sources who have been instrumental in my modification.
4. Do not remove the cover taping on the damping material when starting this project. You may not like the results, so it would make removal and modification easier.
5. Given the depth of your speakers, you may be able to use BH5 to dampen the back with pleasant results. You may want to start with Sonic Barrier if you want to keep costs low and work your way twords BH5 at a later time - BH5 is $55 a sheet last I checked. If you plan to dampen the sides, it may be best to use lighter thickness, such as Sonic Barrier or other dampen material.
Again, I do not have the CRS, so I cannot say for certian that everything I layed out in the material specifics will give you total 100% satisfaction with your speakers, but the outline on how to proceed should be a solid foundation on how you will want to proceed with the project.
Hopefully this answers your questions.
Good luck!!!
PM1Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
The other problem with CRS+'s, remember, is that the passive radiator is on the rear of the cabinet. Correct me if I'm wrong, but the application of BH5 described here is to the rear wall of the cabinet only. Specifically for CRS+'s, this is not easily accomplished, and definitely not doable behind both drivers. You could, possibly, apply the BH5 to portion of the rear cabinet that doesn't include the opening for the PR, but then one of the drivers will have the BH5 behind it and the other won't (offhand I don't recall if it's the dimensional or stereo driver that is back to back with the PR). It's not sounding to me like this mod is particularly advisable specifically for the CRS+ cabinet, but I continue to be interested in hearing advice from the myriad of people here who are far smarter than me!
Good point you make. Maybe one can use Sonic Barrier and apply it to the sides. One may want to think about applying it to the rear wall of the CRS' drivers ajacent to the PR.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart.
