4355 evnts plans

[frablake]

Hello,
Is there anyone who couls give me the events plans for 4355, Please.

Regards
Francis

[speakerdave]

I'm not sure what you mean. Construction drawings?

[frablake]

I'm not sure what you mean. Construction drawings?

Yes if you have them!

[speakerdave]

Here they are:

http://www.audioheritage.org/vbulletin/showthread.php?11166-4355-Monitor-Plans&highlight=4350

[frablake]

Here they are:

http://www.audioheritage.org/vbulletin/showthread.php?11166-4355-Monitor-Plans&highlight=4350

Lot of thanks, but i don't understand the real size of the events lengh. I have just bought a JBL 4355, but they are in very bad condition. Events are destroyed...Could you explain me how i can make them, in what material, and exactly what are the sizes???

Kind regards
Francis

[Odd]

All measurements are in the drawing, in inches.
1 inches = 2.540cm
You can build with plywood or MDF.

[frablake]

All measurements are in the drawing, in inches.
1 inches = 2.540cm
You can build with plywood or MDF.

On this pic: I have not the size of the events! Have you more details about them! Lengh, etchttp://www.audioheritage.org/vbulletin/attachment.php?attachmentid=16228&stc=1&d=1150660163

[ivica]

On this pic: I have not the size of the events! Have you more details about them! Lengh, etc



Owing to the JBL info :
http://www.jblpro.com/pub/obsolete/4355.pdf

that 4355 internal volume is about 265Lit ( 9.5ft3), and that tuning frequency is 32Hz, it seems that for 5"3/8 tube mean length would have to be about 6"3/8, but looking at the presented figure, it seems to me that they are over 11" in length, but if box is tuned on about 27Hz, then the ducts length would be about 11"1/2
Regards
ivica

[Odd]

Ok, the length of the duct, port.
Can not find the exact measurements, but you can find more info here (http://www.audioheritage.org/vbulletin/showthread.php?10971-4350B-4355-Difference)

Use Google to search the forum.
site: audioheritage.org jbl ......





On this pic: I have not the size of the events! Have you more details about them! Lengh, etchttp://www.audioheritage.org/vbulletin/attachment.php?attachmentid=16228&stc=1&d=1150660163

[yvonf]

Hello JBL lovers :)

By the way I am looking for the same information.....

And the answer you gave here is NOT correct (sorry...:dont-know:) : in the 4355 the duct port is NOT vertical mounted ; so the appreciation on a (little) plan isn't so efficient... despite we have also a front view which should "theoricaly" trigo-solve the problem, but in this case the precision would be "pour le moins fantaisiste"... :blink: - I did it !

(I send also PM to Rick-Saeman but no answer... holidays ?) :beach:

Anyway :

It's an old dream for me to have these 4355.... and, until I have the "correct" house, I start one month ago, to modelise in 3D this fantastic monitor with "SolidWorks" and to complete that job (very big job - I already spend on it an hundred "holidays hours"... ), I need a bunch of details...

Here they are :

- thickness of the bafle (3/4 like 4350 or 1 like other main panels ?)
- list of panels with rockwool (all ? outside mid-bass box ? behind bafle ?.....)
- bolts standart (UNC, UNF, SW, BSF, .......) (*)
- RVB informations for blue of the bafle, grey of the compression stuff (ex : 2311) and "blue-grey" of the grille tissus....
- name (or the more similar) of the JBL font (used for label - not for the sigle)
- and of course : the duct port !!!!

For this last, the needed informations are :
1st - angle (just one ? - on the original technical doc, it appears have two...)
2nd - lenght of the first part
3rd - lenght of the second
The sw calculate all the dependant ! "très pratique" !!! :p)
- insertion lenght in the bafle

exemple :


56306

Rem : Well understanding, the lenghts and angle describe in this picture are only aproximate deductions from pictures ....

And to prove the reality of my work that I will - of course - give to this forum (up it's complete... ), some exemples :

The famous duct port :


56308


A partial 3D view of the monster :


56309

Rem : the JBL logo on the 2441 support is just to test "stamp" on a piece (actualy, i learn this sw... and I'm not a specialist but "je me soigne !" )

Anyway, it's amazing ! Imagine : you can move around, see inside, light some parts...... :bouncy:

SO gentlemen PLEASE - PLEASE - PLEASE, answer ..... :help:

French and best regards :)

Yvon

(*) : Anglosaxons should consider ISO....... :crying:

[frablake]

Owing to the JBL info :
http://www.jblpro.com/pub/obsolete/4355.pdf

that 4355 internal volume is about 265Lit ( 9.5ft3), and that tuning frequency is 32Hz, it seems that for 5"3/8 tube mean length would have to be about 6"3/8, but looking at the presented figure, it seems to me that they are over 11" in length
Regards
ivica
Thanks..i understand you, but i would like to know the right angle between the two tubes, and the right lengh of each other.
I was quite amazed when i have looked into the cabinet, by the event form!!!

[frablake]

Hello JBL lovers :)

By the way I am looking for the same information.....

And the answer you gave here is NOT correct (sorry...:dont-know:) : in the 4355 the duct port is NOT vertical mounted ; so the appreciation on a (little) plan isn't so efficient... despite we have also a front view which should "theoricaly" trigo-solve the problem, but in this case the precision would be "pour le moins fantaisiste"... :blink: - I did it !

(I send also PM to Rick-Saeman but no answer... holidays ?) :beach:

Anyway :

It's an old dream for me to have these 4355.... and, until I have the "correct" house, I start one month ago, to modelise in 3D this fantastic monitor with "SolidWorks" and to complete that job (very big job - I already spend on it an hundred "holidays hours"... ), I need a bunch of details...

Here they are :

- thickness of the bafle (3/4 like 4350 or 1 like other main panels ?)
- list of panels with rockwool (all ? outside mid-bass box ? behind bafle ?.....)
- bolts standart (UNC, UNF, SW, BSF, .......) (*)
- RVB informations for blue of the bafle, grey of the compression stuff (ex : 2311) and "blue-grey" of the grille tissus....
- name (or the more similar) of the JBL font (used for label - not for the sigle)
- and of course : the duct port !!!!

For this last, the needed informations are :
1st - angle (just one ? - on the original technical doc, it appears have two...)
2nd - lenght of the first part
3rd - lenght of the second
The sw calculate all the dependant ! "très pratique" !!! :p)
- insertion lenght in the bafle

exemple :


56306


And to prove the reality of my work that I will - of course - give to this forum (up it's complete... ), some exemples :

The famous duct port :


56308


A partial 3D view of the monster :


56309

Rem : the JBL logo on the 2441 support is just to test "stamp" on a piece (actualy, i learn this sw... and I'm not a specialist but "je me soigne !" )

Anyway, it's amazing ! Imagine : you can move around, see inside, light some parts...... :bouncy:

SO gentlemen PLEASE - PLEASE - PLEASE, answer ..... :help:

French and best regards :)

Yvon

(*) : Anglosaxons should consider ISO....... :crying:

Sublime travail, bravo...où puis je "visiter" cette merveille, sur quel site web ou avec quel logiciel.

Avez vous des infos plus précises quant à la réalisation des évents? il semble que non...mais si oui, je suis preneur...

Encore mes félicitations pour votre travail

Francis

[frablake]

Hello JBL lovers :)

By the way I am looking for the same information.....

And the answer you gave here is NOT correct (sorry...:dont-know:) : in the 4355 the duct port is NOT vertical mounted ; so the appreciation on a (little) plan isn't so efficient... despite we have also a front view which should "theoricaly" trigo-solve the problem, but in this case the precision would be "pour le moins fantaisiste"... :blink: - I did it !

(I send also PM to Rick-Saeman but no answer... holidays ?) :beach:

Anyway :

It's an old dream for me to have these 4355.... and, until I have the "correct" house, I start one month ago, to modelise in 3D this fantastic monitor with "SolidWorks" and to complete that job (very big job - I already spend on it an hundred "holidays hours"... ), I need a bunch of details...

Here they are :

- thickness of the bafle (3/4 like 4350 or 1 like other main panels ?)
- list of panels with rockwool (all ? outside mid-bass box ? behind bafle ?.....)
- bolts standart (UNC, UNF, SW, BSF, .......) (*)
- RVB informations for blue of the bafle, grey of the compression stuff (ex : 2311) and "blue-grey" of the grille tissus....
- name (or the more similar) of the JBL font (used for label - not for the sigle)
- and of course : the duct port !!!!

For this last, the needed informations are :
1st - angle (just one ? - on the original technical doc, it appears have two...)
2nd - lenght of the first part
3rd - lenght of the second
The sw calculate all the dependant ! "très pratique" !!! :p)
- insertion lenght in the bafle

exemple :


56306


And to prove the reality of my work that I will - of course - give to this forum (up it's complete... ), some exemples :

The famous duct port :


56308


A partial 3D view of the monster :


56309

Rem : the JBL logo on the 2441 support is just to test "stamp" on a piece (actualy, i learn this sw... and I'm not a specialist but "je me soigne !" )

Anyway, it's amazing ! Imagine : you can move around, see inside, light some parts...... :bouncy:

SO gentlemen PLEASE - PLEASE - PLEASE, answer ..... :help:

French and best regards :)

Yvon

(*) : Anglosaxons should consider ISO....... :crying:

En fait je trouve qu'il y a déjà beaucoup d'informations ...peut-on s'envoyer des MP?

[speakerdave]

JBL has long been tight-lipped about the details of the port ducts in its cabinets. For one thing, they were not particularly interested in having the cabinets replicated while the speakers were in production. A more important reason now is that in a DIY cabinet many if the details of construction will vary from the factory version, and these variations may affect the length of duct needed to achieve the desired tuning. In other words, it is very likely your cabinets will need to be individually tuned. Still, it is desirable to know as many of the details as possible, so what is needed here is for someone owning a pair of factory cabinets to make some careful measurements and post them here just as has been done with the 4345, 4333, 4430 and others. Perhaps a forum member who has a pair can take the time.

[ivica]

JBL has long been tight-lipped about the details of the port ducts in its cabinets. For one thing, they were not particularly interested in having the cabinets replicated while the speakers were in production. A more important reason now is that in a DIY cabinet many if the details of construction will vary from the factory version, and these variations may affect the length of duct needed to achieve the desired tuning. In other words, it is very likely your cabinets will need to be individually tuned. Still, it is desirable to know as many of the details as possible, so what is needed here is for someone owning a pair of factory cabinets to make some careful measurements and post them here just as has been done with the 4345, 4333, 4430 and others. Perhaps a forum member who has a pair can take the time.

Interestingly to say, for the JBL model 4355 internal volume (265Lit) and the tuning frequency (32Hz) were given in the:
http://www.jblpro.com/pub/obsolete/4355.pdf

but from the most of the DIY people that have a "contact with" the original seems that tuning frequency is about 27Hz, even though that with 32Hz tuning calculated response is 'flatter' and -3dB point is lower then tuning of about 32Hz. I believe that in the room 27Hz tuning would give lower response.

[frablake]

JBL has long been tight-lipped about the details of the port ducts in its cabinets. For one thing, they were not particularly interested in having the cabinets replicated while the speakers were in production. A more important reason now is that in a DIY cabinet many if the details of construction will vary from the factory version, and these variations may affect the length of duct needed to achieve the desired tuning. In other words, it is very likely your cabinets will need to be individually tuned. Still, it is desirable to know as many of the details as possible, so what is needed here is for someone owning a pair of factory cabinets to make some careful measurements and post them here just as has been done with the 4345, 4333, 4430 and others. Perhaps a forum member who has a pair can take the time.

Hi Sir
lot of thanks for your comment. It is very interesting.

[frablake]

Hi Sir
lot of thanks for your comment. It is very interesting.
Hello Sir, i find a 36.69 cms lengh for 25Hz. Do you agreee?

[speakerdave]

Hello Sir, i find a 36.69 cms lengh for 25Hz. Do you agreee?

If someone says "sir" in my presence I always get whiplash looking around to see who they're talking to.

I don't have any data on the tuning of the 4355, but that length seems way long, certainly much longer than what we know from sketches. Where did you get the 25 Hz target figure?

[speakerdave]

Here's another thread on the box:

http://www.audioheritage.org/vbulletin/showthread.php?12037-4355-Enclosure-Plans

[frablake]

If someone says "sir" in my presence I always get whiplash looking around to see who they're talking to.

I don't have any data on the tuning of the 4355, but that length seems way long, certainly much longer than what we know from sketches. Where did you get the 25 Hz target figure?

25 Hz is the best for two 2235H.

[speakerdave]

25 Hz is the best for two 2235H.

I don't know? I'm really not the one to be your cabinet tuning consultant, but . . . . where did this "best" tuning come from?

Is that JBL's tuning?

Isn't JBL's tuning 32 Hz? I thought you wanted to replicate the original.

How many ports does your duct length assume?

[frablake]

I don't know? I'm really not the one to be your cabinet tuning consultant, but . . . . where did this "best" tuning come from?

Is that JBL's tuning?

Isn't JBL's tuning 32 Hz? I thought you wanted to replicate the original.

How many ports does your duct length assume?

Here is the source:

Courbe de réponse, FB et Fréquence de coupure à -3 dB :


Définition
Paramètre
Valeur
Formules de calcul


Volume bass-reflex
VB
256.0 L
Volume de calcul


Coeficient de volume
N
4.02
VB/(VAS*Qtsb2)


Optimisation de la courbe de réponse
Opt
FB est forcé à 24.9 Hz


FB pour 256.0 L
FB
24.9 Hz
Précision du calcul à 0.1 dB


Niveau à 24.9 Hz
EFB
-8.8 dB
Niveau à FB


F à -3 dB pour 256.0 L
( En champs libre (http://petoindominique.fr/php/champs_libre.php), donc dehors )
F-3 dB
37 Hz
Chapitre enceinte bass-reflex (http://petoindominique.fr/php/br.php)
Arrondi au dB le plus proche


F à -6 dB pour 256.0 L
( Niveau à -3 dB dans votre salon )
F-6 dB
29 Hz


F à -12 dB pour 256.0 L
F-12 dB
21 Hz


F à -24 dB pour 256.0 L
F-24 dB
13 Hz



Courbe de réponse en champs libre du JBL 2235H, VB = 256.0 L, FB = 24.9 Hz, le 0 dB correspond à 100.0 dB/2.83V/m.
Rouge : Réponse en champs libre. Bleu : Réponse avec car gain.
Vert : Correction Hi-FI embarquée ou Room gain. Pente : 0.00 dB/octave en dessous de 0 Hz.
http://petoindominique.fr/mysql_s/graph_br_db.php?dbabr=a:11:%7Bi:0;d:19.58236526575 50013600484817288815975189208984375;i:1;d:24.89999 999999999857891452847979962825775146484375;i:2;d:9 17.460021972656022626324556767940521240234375;i:3; d:256;i:4;d:6.998000571265351688055034173885360360 14556884765625;i:5;d:0.263319286316610001730253998 175612650811672210693359375;i:6;d:0;i:7;d:0;i:8;d: 35;i:9;d:10;i:10;d:70;%7D
Of course i want to replicate the original, but i have to resolve the event problem..so i use mathematic to do that..

[speakerdave]

I'm no good with French. If you want to use this approach, then try it and see if you like the result. If you do, all is well.

[Lee in Montreal]

@ frablake. I suggest using a simulation software to get your "best" tuning. "Best" is only a compromise. What good does it make to tune to 27Hz if you loose many db at, say, 35Hz, or hit max excursion at even low levels...

Lee

[4313B]

25 to 30 Hz is fine. I usually tune to around 28 Hz. The dimensions of the stock JBL ducted ports are arguably meaningless unless you use the same fiberglass fill JBL used.

[ivica]

Here's another thread on the box:

http://www.audioheritage.org/vbulletin/showthread.php?12037-4355-Enclosure-Plans

Unfortunately, there is NO DATA about the ducts.....:-()
Regards
Ivica

[ivica]

Here is the source: Courbe de réponse, FB et Fréquence de coupure à -3 dB :

Définition
Paramètre
Valeur
Formules de calcul


Volume bass-reflex

VB
256.0 L
Volume de calcul


Coeficient de volume
N
4.02
VB/(VAS*Qtsb2)


Optimisation de la courbe de réponse
Opt
FB est forcé à 24.9 Hz


FB pour 256.0 L
FB
24.9 Hz
Précision du calcul à 0.1 dB


Niveau à 24.9 Hz
EFB
-8.8 dB
Niveau à FB


F à -3 dB pour 256.0 L ( En champs libre (http://petoindominique.fr/php/champs_libre.php), donc dehors )
F-3 dB
37 Hz
Chapitre enceinte bass-reflex (http://petoindominique.fr/php/br.php) Arrondi au dB le plus proche


F à -6 dB pour 256.0 L ( Niveau à -3 dB dans votre salon )
F-6 dB
29 Hz


F à -12 dB pour 256.0 L
F-12 dB
21 Hz


F à -24 dB pour 256.0 L
F-24 dB
13 Hz



Courbe de réponse en champs libre du JBL 2235H, VB = 256.0 L, FB = 24.9 Hz, le 0 dB correspond à 100.0 dB/2.83V/m. Rouge : Réponse en champs libre. Bleu : Réponse avec car gain. Vert : Correction Hi-FI embarquée ou Room gain. Pente : 0.00 dB/octave en dessous de 0 Hz.

Of course i want to replicate the original, but i have to resolve the event problem..so i use mathematic to do that..


It has to be aware that in 4355 there were TWO DRIVERS, so their mutual coupling has to be considered too. That is the reason why some has used 2234 pair instead of 2235 drivers.... Unfortunately most of the programs do not "pay attention" to the drivers mutual coupling, because in such situation drivers mutual distance is important parameter over frequency ( distance = lambda/2) say 150Hz ~ 250Hz...
Nice presentation at;

http://www.zainea.com/mutualcoupling.htm (http://www.zainea.com/mutualcoupling.htm)

I2/I1 = 2*[1 + sin(k*d)/(k*d) ],

where k= 2*pi/Lambda,
d= drivers center distance

This is for on-axis response, but for off-axis response, the problem would be more complicated in some On JBL DD66000 such is visible too. ElectroVoice product literature: "When two speaker systems are placed side by side, the woofer cones “mutually couple,” causing the two systems to act as one system with twice the effective cone area at very-low frequencies, giving an additional 3-dB increase in maximum acoustic output. Mutual coupling will occur when the frequency is such that the center-to-center distance between the two woofer manifolds is less than about one-half wavelength." Fo = c/(d*sqrt(n)) Where "c" is the speed of sound in the air in metres per second (normally 343 is used, but can vary slightly according to air temperature and humidity). "d" is the distance in metres between the two speakers "n" is the number of sources. Fo = 344 / ( 0.5m * 1.4142 ) = 487 Hz

http://www.diyaudio.com/forums/subwoofers/52414-mutual-coupling-question.html#post585439

From the JBL Sound System Design Reference Manual:
".......The phenomenon of mutual coupling always comes to our aid in increasing the power output of combined subwoofer units. Figure 7-6A shows the transmission coefficient for a direct radiator as a function of cone diameter. The solid curve is for a single unit, and the dotted curve is for two units positioned very close to each other. In addition to the double power handling capability afforded by the two units, the dotted curve shows a 3 dB increase in transmission coefficient at low frequencies. This is due basically to the tendency for the two drivers to behave as a single unit with a larger cone diameter, and hence higher efficiency. Thus, at B, we see the relative response of a single woofer (solid curve) compared to two such radiators (dashed curve). Note that the upper frequency transition point for the pair is 0.7 that of the single unit. The more such units we combine, the lower the effective cut-off frequency below which mutual coupling is operant. As an example, let us pick a large cinema with the following physical parameters: V = 14,000 m3 S = 3700 m2 T60 = 1.2 seconds R = 2500 m2 We will use the JBL 2242H LF transducer. Taking into account its power rating and its dynamic compression at full power, we note that its power output in acoustic watts will be: WA = (WE x reference efficiency)10-dB/10 where WE is the transducer’s continuous power rating (watts) and -dB is the transducer’s power compression at full power. Substituting the values of WE of 800 watts, reference efficiency of .004, and power compression of 3.3 dB, we get the value of 15 acoustical watts. The reverberant level in a space with a room constant of 2500 is then: LREV = 126 + 10 log 15 - 10 log 2500 = 104 dB SPL We can now construct the following table: Number of Units Maximum Level Power Input 1 104 dB 800 W 2 110 dB 1600 W 4 116 dB 3200 W We cannot continue this process much beyond that shown here. What happens is that the frequency below which mutual coupling takes place falls below the nominal cutoff frequency of the system, and eventually all we see is a simple 3 dB increase per doubling of elements. For multiple subwoofers outdoors, it is best to assume that levels fall off according to inverse square law. I would welcome a simpler explanation. ......"

Regards Ivica

[stephane RAME]

http://www.jblproservice.com/pdf/Studio%20Monitor%20Series/4355.pdf

Stéphane

[yvonf]

Hello

Some forumers ask for the 4355 CAD Solidworks...
You can download it at :
http://www.mediafire.com/file/6thltu57c0d9tae/JBL_4355_-_Dossier_technique_Solidworks.rar/file

Please keep in mind than all the dimensions are correct exept the event !

Sincerely :)

Yvon

[discus96]

Hello

Some forumers ask for the 4355 CAD Solidworks...
You can download it at :
http://www.mediafire.com/file/6thltu57c0d9tae/JBL_4355_-_Dossier_technique_Solidworks.rar/file

Please keep in mind than all the dimensions are correct exept the event !

Sincerely :)

Yvon


Thank you yvonf,


Great Job with Solid Works!

[yvonf]

Thank you yvonf,
Great Job with Solid Works!

Hello
I forgot to reply to you to thank back for this sympatic message :)
More than 100 download and only you.... ;)
Yes actually it took a lot of hours ! :spin: but by the way, an opportunity for me to learn this CAD software :p
Happy new year
Sincerly
Yvon