PDA

View Full Version : S3100 resonant frequency



Bernard Wolf
10-27-2003, 09:29 AM
Hi - I know on the last forum someone answered this question for me but I can no longer find the posting. Does anyone happen to know what the resonant frequency of the 3100 is ? I am planning to use some EQ and do not wish to boost below that frequency.

Many thanks - Bernard

4313B
10-27-2003, 09:43 AM
G.T. thought it was in the 30 to 35 Hz range but he couldn't remember for sure. I believe that he recommended not boosting much below 30 Hz. You can measure Fb yourself or have it measured by someone with the necessary equipment. Here is a link that describes several methods JBL recommends - JBL Enclosure Information Manual (http://lansingheritage.org/html/jbl/plans/1979-manual.htm)

Bernard Wolf
10-27-2003, 10:27 AM
Thanks Gisgard. I think you are right about the 30-35 hz range as that is what I also seem to recall. I guess I may try to borrow an ocillator and give it a whirl. I am thinking of trying a Marchand Electronics WM8 BASSIS bass correction eq.

Thanks

Jan Daugaard
10-29-2003, 02:19 AM
Hi Giskard,

some time ago you provided the T/S parameters for the ME150H as follows:

Fs = 38 Hz
Qms = 6.4
Vas = 130.3 liters
Cms = 0.116 mm/N
Mms = 0.153 kg
Rms = 5.708 mohms
Xmax = ?
Xmech = ?
P-Dia = 337.5 mm
Sd = 0.089 sq.m
Vd = ?
Qes = 0.35
Re = 5.6 ohms
Le = 1.12 mH
Z = 6.72 ohms
BL = 24.2 N/A
Pe = ?
Qts = 0.33
no = 1.969 %
1-W SPL = 95.09 dB
2.83-V SPL = 96.64 dB

I'm still wondering what Rms and Pe are?

Earl K
10-29-2003, 05:30 AM
Hi Jan

Hope this helps;


Fs = 38 Hz I believe you'll find it's more like 28 hz. Since you have a pair . Why not take out one of those brutes and measure Fs for us . Pics would be nice .


Rms and Pe ???

I don't know what Rms might represent .

Pe is power handling in rms watts.

It looks like JBL didn't do a full TS workup. That's likely because the speaker wasn't meant for "over the counter" sales. Reconing appears to be a no-go. Only replacement drivers appear to be avaliable. That sort of makes sense. There may be a huge QC issue at play here. Something more than just dropping a 2235h cone-kit into a 2227h must be at work here. Tinkering with added mass , etc. to get the target weight mms / Fs would be my speculation . Maybe even a rim-ring shim is necessary to centre the coil in the gap - it's all unknown to me .

regards <. Earl K :)

4313B
10-29-2003, 07:37 AM
"I believe you'll find it's more like 28 hz."

One might obtain that Fs after break in, which would also change other parameters. Bottom line - measure the TS parameters of your own drivers after you break them in.

"It looks like JBL didn't do a full TS workup."

This is internal information - it isn't for general public consumption.

"That's likely because the speaker wasn't meant for "over the counter" sales."

You got it :)

"I'm still wondering what Rms and Pe are?"

Here are some links you can read through -

UNDERSTANDING LOUDSPEAKER DATA (http://editweb.iglou.com/eminence/eminence/pages/params02/params.htm)

Impedance measurement and Thiele-Small parameters computation (http://www.purebits.com/appnote16.html)

There are many, many other sites you can get information from as well.

Jan Daugaard
10-29-2003, 11:30 AM
Hi Earl K,

I downloaded 2 pictures of the ME150H in August 2002, probably from this site, so I don't have to take one of my four S3100 apart to see it.

Jan Daugaard
10-29-2003, 11:33 AM
And another picture of the ME150H:

Earl K
11-22-2004, 04:43 PM
And up we go !


One might obtain that Fs after break in, which would also change other parameters. Bottom line - measure the TS parameters of your own drivers after you break them in.

I've only broken in 2 of my 4 ME150H woofers. Both settled into an Fs of about 27.5 hz.

And yes, the rest of the TS parameters are in need of some updating .

I might pay someone in the new year to do a pro workup of them .

, Earl K

Bernard Wolf
11-22-2004, 06:17 PM
Thanks for that info Earl.... now I know I can boost down to 30 hz. That should save me the need for a sub.


Bernard

Earl K
11-22-2004, 06:26 PM
Hi Bernard

You're welcome. :D

Remember though, the "box tuning" of your S3100 is not likely much lower than 32 or 33 hz ( my guess based on running some tunings ) .


Have you ever "sized" your enclosures to get a "guesstimate" of their internal volume ? FWIW, that enclosure "seems" quite oversized for the unofficial TS parameters . ;)

It seems these newer generation woofers don't mind operating as "under-damped" systems .

regards <. Earl K

Bernard Wolf
11-22-2004, 06:40 PM
Hi Earl - well, I'm not much of a "techie" - just like to listen to music :) ... but with reference to what you just posted, I was lead to believe that the s3100 was overdamped ..:confused: what gives ? In any case, as I do now boost occasionaly at 40hz, depending on the music, 32 hz would be real interesting although I will need a different eq as mine bottoms out at 40.

Bernard

Earl K
11-22-2004, 06:51 PM
Hi Bernard,

Regarding what I just posted above. It's merely speculation on my part based on running numbers through a software package with suspect TS parameters .

My woofers are operating in @ 2.8 cu' test enclosures - tuned to about 40 hz.

This size, definately gives a very "over-dampened" sound . Very constrained .

That's why I was curious about the internal dimensions for the S3100.
Both you and Jan have spoken very highly of this system .

<. Earl K

Bernard Wolf
11-22-2004, 06:56 PM
well then, I will try to figure out the internal dimensions for us all. Let you know.. if I manage that is.. these things are angled as you know so it might take some creative math, at which I am not too good.

B

Earl K
11-22-2004, 07:05 PM
Thanks !

Bernard Wolf
11-22-2004, 07:21 PM
well, my wife just "helped' me with this but I am not certain of the resuts - she came up with 1.66 cu. ft. Does this make sence ? The enclosures are: inside dimensions : approx 39" high, 20" along the front, 13" along the side 9" along the back and then angles up for 15" till it meetts the far side which is 2 " deep. Does this help at all ?

B :banghead:

Earl K
11-22-2004, 09:14 PM
Hi Bernard

Actually, 1.66 cu ft is quite small for the size of enclosure you have .

I expect the volme is in the area of 4 to 6 cu ft .


Does this help at all ?

Yes it does .

I'll take a look at this tomorrow morning. I can extrapolate an internal volume from the dimensions you've posted .

Thanks ! <> Earl K

Bernard Wolf
11-23-2004, 05:56 AM
Thanks Earl - btw, those dimensions are approximate internal as I allowed 1" on all measurements, i.e the front external is actually 22".

Bernard

Earl K
11-23-2004, 06:22 AM
Hi Bernard,

I calculate a "gross" internal volume of @ 4.5 cu ft.

"Net" internal volume is likely smaller considering the displacement of that H2600 horn. I don't think the typical 1" fiberglass "stuffing" will offset that horns' large internal dimensions .
So, my guess, is that net "virtual" volume is around 4 to 4.25 cu ft.

Thanks for the measurements !

<. Earl K

spirou38
11-24-2004, 04:06 AM
Hi Bernard,

One year ago I owned a pair of S3100MKII. I think the woofer was also a ME150HS. I am shure that the woofer was slightly hihger from the floor than on the S3100 and that the resonnace frequency was not exavtly the same.
I remember that I mesured a big bass boost of 14 dB at 32 Hz. I hope it could help you.

Pascal

Bernard Wolf
11-24-2004, 06:17 PM
Hi Pascal - thanks for the input, but from all the info I can gather the MKII is exactely the same other then the neobendyume tweeter. That bass boost seems awfully high.. where was the speaker placed ? In a closet ?:D BTW, I see you now own another type of JBL - I don't know the nomenclature - how does the sound differ from the S3100?

Bernard

spirou38
11-25-2004, 04:18 AM
Hi Bernard,

Yes, the S3100 compression driver is a 2426H and in the S3100 it's a 275ND, but there are also physical differences between the S3100 and the S3100MKII that we had in France : on the latter, the woofer is about 3" higner from the floor side and the cabinets have not exactly the same dimensions, the MKII is higher ( I hope you will understand my poor english :rolleyes: ). I will try to find the ad about the S3100 and the S3100MKII if I kept them. If you are interested in, I know that I have a test of the S3100 that I founded in "La nouvelle revue du son", but sorry, it will be in french :D and I can send it to you or email you a scan.

Unluckyly I couldn't put my pair of S3100MKII neither in the toilets nor in the bathroom :mad: , so I was obliged to put them in the dining room that was about 48 square meters :D and changing the position of the speakers didn't change the 32 Hz bass boost. The best position was about 0.9 meters from the side walls and 1.5 meters from the rear wall.

Before bying my 4344MKII, I had to sell my S3100MKII because my wife said I had enough speakers :mad: ( at that moment, I also owned a pair of JBL S2600, a pair of Martin Logan Sequel II and a pair of Infinity Kappa 7 ) ; and I bought a pair of 4344MKII. The speakers that are used are ME150HS ( same than S3100 ), 2123H, 275 ND ( same than S3100MKII ) and 2405H. Thus, I had a trouble with one of the 275ND which level was more than 6 dB lower than the good one, but, thanks to Giskard, I changed it and now it works very fine :) . Also thanks to my Tact RCS that, in correction mode, succeded in correcting the problem ;) .

Pascal

Bernard Wolf
12-06-2004, 11:50 AM
Hey Pascal - you never did tell me how you thought the S3100 compared to the 4344 MKii. I am very curious to know because I have yet to hear any JBL other than the S3100 and so have no idea where they stack up in comparison to the other more conventional JBL's. Your opinion would be of real interest to me seeing as you have had both.

Thanks - Bernard

spirou38
12-06-2004, 01:26 PM
Hey Pascal - you never did tell me how you thought the S3100 compared to the 4344 MKii. I am very curious to know because I have yet to hear any JBL other than the S3100 and so have no idea where they stack up in comparison to the other more conventional JBL's. Your opinion would be of real interest to me seeing as you have had both.

Thanks - BernardHi Bernard,

My S3100 were MKII model with 275ND instead of 2426. As I also owned S2600 with 2426, so I can tell you that the MKII is smother, nos as metalic than the non MKII model, and the treble seems to go higher and easier.

Now, the differences between the S3100 and the 4344MKII : you can compare with cars : the 3100 has a 4 cylinders engine and the 4344MKII a very powerful 8 cylinders : the 3100 has the same bass driver than the 4344 but in a smaller cabinet and the mid/ high driver is a 2426.

Instead of a 2426, the 4344 has a 2123 for mid bass, a 275ND for medium and a 2405 for high frequencies. So imagine the difference ! On my 4344, I recently mesured a bass boost of 19 dB at 29 HZ in the same room where I had my 3100 ; the boost is higher than in the 3100, but the frequency is lower, probably because of the size of the cabinet. But with the TACT RCS2.2 correction room system, it is not a problem :D .

Always about the bass, it is different, its cleaner in the 4344, thus using the same speaker because they are bi-amped and in the 4344 there is a switch to bypass some components ( a 6 mH choke in the bass section and capacitors and resistors in the medium section ). You can easily hear the difference with the switch !

About the mid bass, medium and high frequencies, you get much more details, it also seems to be faster and much more easier. But the 3100 has a dispersion horn that makes a lot of work. It reminds me the Everest serie.

However the 3100 is always a 4 cylinders ... but you can add a turbo on it : a friend of mine tweaked his 3100 several years ago. I know that he damped the outer side of the horn ( I think it was with lead and tar ) and he added a 2405H for high frequencies. I will ask him if he kept some notes about his mods.

Note that you can qualify S3100 and S3100MKII as very good speakers, even if they are just 2 ways, don't forget they have a fabulous dispersion horn. I prefer a S3100MKII to a 250Ti or even to a Ti10K that are too insipid, too flat and without life.

A good new, Bernard : when I sold my 2600 and 3100, I gave the buyer the tests of the specialised revues, but before I scanned them, and yesterday I found them on an old save of my computer :) ! But the bad new is that is is in french :( . If you need of those tests, I could send you those by mail.

I hope I answered to your questions. Don't hesitate if you have any others.

Pascal

Bernard Wolf
12-06-2004, 03:16 PM
Thanks Pascal - that helps a lot. I'm surprised your friend would damp the horn as it is some kind of space age plastic to begin with and I really do not see how it would ring. You are right about the asymmetrical horn being fabulous - I would be hesitant to trade that for anything I have ever heard. I guess like everything else there are always trade-offs.

Thanks for the offer of the articles but I have some revierws from the British mags that will do me, plus I know what I hear :D . I have thought about a supertweeter and perhaps some day I will.. as for the bass.. in my quite large (650 sq.ft) listening room I do get enough extensiion for me with the help of some eq.

thanks again

Bernard

spirou38
12-08-2004, 08:05 AM
.

... a friend of mine tweaked his 3100 several years ago. I know that he damped the outer side of the horn ( I think it was with lead and tar ) and he added a 2405H for high frequencies. I will ask him if he kept some notes about his mods ...


PascalHi Bernard,

Sorry, my friend didn't add a 2405H, but that tweak was often done especially on S3100 non MKII, probably because of the 2426. But he put lead all around the dispersion horn, glued with a kind of tar and bi-amped his 3100. I forgot asking if he bypassed the choke in the low pass filter :( .

Pascal

Bernard Wolf
12-11-2004, 08:47 PM
Hi Bernard,

I calculate a "gross" internal volume of @ 4.5 cu ft.

"Net" internal volume is likely smaller considering the displacement of that H2600 horn. I don't think the typical 1" fiberglass "stuffing" will offset that horns' large internal dimensions .
So, my guess, is that net "virtual" volume is around 4 to 4.25 cu ft.

Thanks for the measurements !

<. Earl K
Hi Earl - so then tell me, what does this mean ? If your drivers are running 'overdamped' at 2.5 cu ft. internal volume what does this make the S3100 ? I have been led to believe that they are also overdamped. If this is so then what kind of internal volume would it take to make them 'damped' and, I assume, put out deeper, not more - as they do plenty as is - bass?

Bernard

Earl K
12-12-2004, 04:42 AM
Hi Bernard


If your drivers are running 'overdamped' at 2.5 cu ft. internal volume what does this make the S3100 ?

I imagine that the S3100 has an overall system tuning that is fairly close to sounding "Critically Damped".



I have been led to believe that they are also overdamped.

No , I doubt if that is the case. Although; combining the deep gap of the ME150h woofer , with it's Aquaplassed cone and then adding in the passive crossovers' load resistors, will give a woofer/box/system "tuning" that sounds controlled or "tight". To some peoples "ears" - this might sound "over-damped" .


If this is so then what kind of internal volume would it take to make them 'damped' and, I assume, put out deeper, not more - as they do plenty as is - bass?

I'm just speculating here - but from my experience in just listening to this highly controlled woofer ( and comments from you and others like Jan ) - the woofer might happily operate in a 6 cu' enclosure ( as in the days of yore ) before giving a "hint" of starting to "lose it". On paper ( according to my "blinking/fritzing" software ) this becomes an overall sytem tuning of around .425. This is "underdamped" territory, no matter what "box tuning or Fb" is actually chosen. It'll provide an extended but "droopy" bottom-end curve that would require a complete redesign of your S3100 crossover ( so don't go there ). It might be useful in the bottom box of an MTM setup . I might eventually try that out .

regards <> Earl K

Bernard Wolf
12-12-2004, 06:46 AM
Hi Earl - thanks again for all of your thoughtfull information. You may well be right that the ME150h has been made to sound tight but somewhat rolled off in the bass. I really did think, though that many times I have heard of this tranducer being refferred to as 'overdamped'. I wish there was more detailed information available on this site but for some reason the S3100 is not mentioned at all in the listings. I wonder why ?

Anyways, thanks again and happy shovelling ;)

Bernard

Earl K
12-12-2004, 01:10 PM
Bernard ,

I really did think, though that many times I have heard of this tranducer being referred to as 'overdamped'.

Well I forget ( of course ), but was I a member of this informed crowd - that talked about this specific woofer being "over-damped" ?
:spin: :rotfl: :spin:

regards <. Earl K

johnaec
12-12-2004, 04:49 PM
combining the deep gap of the ME150h woofer , with it's Aquaplassed cone and then adding in the passive crossovers' load resistors, will give a woofer/box/system "tuning" that sounds controlled or "tight". Frankly, I was really surprised no one from the forum picked these up - 'seemed like a good deal...: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5734907771&ssPageName=STRK:MEWA:IT

John

Earl K
12-12-2004, 04:59 PM
'seemed like a good deal.

Yeh, I "watched" that auction, the final price was a great deal, IMO, for someone who's looking for this sort of bass/midbass accuracy .

Worth Mentioning ; This ME150h woofer is "not" a subwoofer as mentioned in that eBay advert.

The 2235h out-"woofs" the ME150h in the VLF range. So there will likely be more people who favour its' ( the 2235h ) sonic-balance or signature .

<. Earl K

4313B
12-12-2004, 07:01 PM
I really did think, though that many times I have heard of this tranducer being refferred to as 'overdamped'.The ME150HS, like many JBL low frequency transducers, is overdamped by design.

Bernard Wolf
12-12-2004, 08:17 PM
Frankly, I was really surprised no one from the forum picked these up - 'seemed like a good deal...: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5734907771&ssPageName=STRK:MEWA:IT

JohnMan.. wish I would have seen that .. at the price they would have made a good back-up although I wounder if will ever use mine up.:confused: I am 55 yrs old you know! Heck of a price - $295.00 the pair!!

Bernard