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maabx
10-13-2005, 06:39 AM
http://www.glht.net.cn/aa/bbs/upload/cpb2_200412811259.jpg


Can anyone comment on the 'grille bars' placed across the tweeter. Is this just protection from poking fingers? The above picture is the S38II. The first Studio series (S38, S310, S312, etc.) had only one central horizintal bar across the tweet. I have seen other JBL series using EOS where one vertical bar is used. The center bar has a smallish 'cap' which cover the center of the tweeters dome. I thought I had read somewhere at one time that the center cap prevented beaming, but why the extra bars?

Thanks, Mike Brown

Titanium Dome
10-13-2005, 07:59 AM
Here's the Ti tweeter and EOS Waveguide on a PT800. One bar w/cap here.

clmrt
10-13-2005, 08:42 AM
Mapleshade's tips for better sound would have you snip those out...:blink:

maabx
10-13-2005, 10:01 AM
That is precisely why I ask. If the intention was for protection of the tweets, I would not hesitate to snip them out. If their is some other purpose, well....:hmm: not sure.

Zilch
10-13-2005, 10:14 AM
I've seen documentation describing the purpose/utility of the contact lens.

Damping, I think.

Don't MAKE me find in now.... :banghead:

maabx
10-13-2005, 10:35 AM
OK, using the phrase "contact lens" I found the following:

http://www.jblpro.com/pub/obsolete/8325a.pdf

It states "A unique acoustic "contact lens" is an integral part of the tweeter design. It aids in flattening the high frequency response by shadowing the center of the dome of the tweeter."

I wonder why the second and third bars were added to the S38II, S310II, etc.?

Titanium Dome
10-13-2005, 10:40 AM
OK, using the phrase "contact lens" I found the following:

http://www.jblpro.com/pub/obsolete/8325a.pdf

It states "A unique acoustic "contact lens" is an integral part of the tweeter design. It aids in flattening the high frequency response by shadowing the center of the dome of the tweeter."

I wonder why the second and third bars were added to the S38II, S310II, etc.?


I'd say that the extra bars are for protection. If they were a distinct design improvement, I'm guessing we'd see them on newer, more expensive models.

Mr. Widget
10-13-2005, 11:08 AM
There have been many tweeters over the years from various vendors with a dot of some sort over the center of the dome. It reduces what would otherwise be a bright sounding on axis response.

Mapleshade... geez. Don't forget to wash the extra electrons off of your speaker cables at the end of each listening session... Mapleshade has just the soap for the task. Only $40 for enough special soap for 100 listening sessions. A bargain really...


Widget

JBLnsince1959
10-13-2005, 12:43 PM
I wonder why the second and third bars were added to the S38II, S310II, etc

because these were sold at Best Buy and people would stick their fingers in the tweeters and screw them up.

Ian Mackenzie
10-13-2005, 12:57 PM
The device is used to correct and the otherwise problematic phase cancellation/peaking issues with domes in certain applications. Just consider why compression driver use a phase plug...

JuniorJBL
10-13-2005, 01:00 PM
Mapleshade... geez. Don't forget to wash the extra electrons off of your speaker cables at the end of each listening session... Mapleshade has just the soap for the task. Only $40 for enough special soap for 100 listening sessions. A bargain really...


Widget


Do they carry woofer and tweeter bearings.......

pelly3s
10-13-2005, 04:01 PM
Do they carry woofer and tweeter bearings.......


they are expensive. they also sell a decive for reallignment of the electrons on the incoming power inorder to increase low end response in your amp

scott fitlin
10-13-2005, 04:18 PM
they are expensive. they also sell a decive for reallignment of the electrons on the incoming power inorder to increase low end response in your ampYes they do, that device is called a " Linear Electron Migrated Frequency Recapitulator "!

I hear they do wonders for Bose!

:)

JuniorJBL
10-13-2005, 04:43 PM
Are the LEMFR's:blink:

scott fitlin
10-13-2005, 05:01 PM
Are the LEMFR's:blink:About $1900ea!

But, if your not snobby about brand names, and can live with not having boutique salon brand names on your audio devices, the LEMFR,s can be had for the budget price of merely a few bucks, available at your local Radio Shack, just get some " Ferrite snap on cores " for your AC cords!

But please, dont tell everyone, as Sopranotronics is making millions selling LEMFR,s that are essentially the same as the RS ferrite cores, the only real difference between the two is the fancy " teflon " outer jacket to protect the ferrite from chipping!

Thanks for understanding!

;)

pelly3s
10-14-2005, 04:48 AM
they also help prevent skin effect which mind you doesnt kick in until around 2 or 3MHz but it will help so you dont hear it

maabx
10-14-2005, 05:09 AM
It is actually kind of ironic that this thread has turned into a sales pitch for Mapleshade. Because I placed an order for their Golden Helix speaker cables on June 28th of this year and still don't have the product. I have not cancelled the order because I want to see how long they will keep the order and still pretend to be filling it every time I call them for a status. As of about six weeks ago, it was going to be shipped within two weeks. I think it's time to get my monthly status. ;)

clmrt
10-14-2005, 06:10 AM
Sorry about that.


Anyone with MSSSSLFD, or whatever that analysys SW is, want to snip out the dome sheild and measure the effect?

Earl K
10-14-2005, 06:53 AM
- Hmmm, I wondered what you guys were going on about .

- So, thank the heavens for Google™ .

- Here's MapleShades' Tweaks section . (http://www.mapleshaderecords.com/tweaks/index.php)
- After a quick look around, I still couldn't find that cable wash . ;)
- For their products; they do offer a 30 day, unconditional, moneyback guarantee .
- I've read Zilches, JBLsince1959 , and Titanium Domes postings' on DIY speaker cable tweaks. Those testamonials coupled with my own experiences on the sound of capacitors would prevent me from any immediate dismissal of this companies products. ( Though that shouldn't be construed as an endorsement ) .
- Here's Enjoy the Musics' review (http://www.enjoythemusic.com/magazine/equipment/0502/clearview.htm) on some of this companies products .
:)

Mr. Widget
10-14-2005, 09:14 AM
Open up your wallets boys... they love you.

I have bought one of their sampler CDs... they have a very back to basics sound to their recordings. It sounds like the musicians are in a large live room with simple honest mike techniques... very basic sort of home made sounding, but it is refreshing for a change of pace.

...but little towers to keep your wires off the floor so they don't touch synthetic carpet??? Get the cable wash. It'll do even more for you if you use it in your ears.


Widget

Earl K
10-14-2005, 09:52 AM
...but little towers to keep your wires off the floor so they don't touch synthetic carpet??? Get the cable wash. It'll do even more for you if you use it in your ears.

- Good One ! ( I wonder what Hydro must expect as a loss factor when burying wires vs the stringing of overhead transmission lines / I do know they think it's a major PITA ! to implement just for those few farmers left out on the land ) ;)

- Seriously now, was there actual cable wash listed at that site ?

:p

Mr. Widget
10-14-2005, 10:01 AM
- Seriously now, was there actual cable wash listed at that site ?


Hell no!

I am sure with nice packaging (with applicator), a slick name, and some story about it's effectiveness, I could sell the stuff... you guys.:banghead:


Widget

scott fitlin
10-14-2005, 06:04 PM
Hell no!

I am sure with nice packaging (with applicator), a slick name, and some story about it's effectiveness, I could sell the stuff... you guys.:banghead:


WidgetWell, my mother always said, " You can sell shit, IF you package it properly "!!!!!

:rotfl:

Titanium Dome
10-14-2005, 10:26 PM
Well, my mother always said, " You can sell shit, IF you package it properly "!!!!!

:rotfl:

I'm not sure how I feel about that, since I've never met your mom but it sounds like she's talking about me. :o:

scott fitlin
10-15-2005, 10:03 AM
I'm not sure how I feel about that, since I've never met your mom but it sounds like she's talking about me. :o:No she wasnt talking about you! This is something she has said from wayyyyyyyy back when. You see, having always been in the amusement buisiness ( Coney Island ) you would be absolutely amazed at what people will fall for, what you can convince them of, if you have a great line of gabber! Seriously, they will believe anything, and buy almost anything!

Theres also another saying! " If you can`t dazzle them with brilliance, baffle em with Bullshit " !

There are some things in the audio market, I believe fall into these categories.

;)

speakerdave
10-15-2005, 10:44 AM
Mapleshade! I've seen their catalogue; it came in the mail after someone gave me a subscription to Stereophile. It's a collusion--OK it's not a collusion, but it might as well be. The tweak marketers shirttail on the glowing reviews for outrageously priced audiophilia. I think it's about compensation. You may not be able to spend $30,000 for an amp, but you can lay out $1300 for a set of wires and hear the difference, which makes you tweak and validates all the other equipment you have (which you could afford) as first rate in its price range. Things like the wire towers are just a little further down the food chain.

David

oldschool
10-15-2005, 05:39 PM
Well i emailed jbl and they told me the three waveguides make the high freq more stable when it comes to dispersion. and protection.I'm no expert,but it would seem having the center waveguide in the center would help stop beaming,but the other two would hinder dispersion.I may try removing those two,unless anybody thanks having three could improve the sound on my s3811s.thanks dennis