DIY cabinet for 030 system

[fracard.64]

Hello everybody!
I'm owner of a 030 system (D130+075+N2600) in a C37 enclosure. I just recapped the Xover and - after a few hours of burning in - I think they sound better than before. They sound fantastic with a 10W n.f.b. amp but I just lack a little bit of bass. Can anybody help me to choice a new enclosure: backloaded horn, like the C34 or 4530, is it really better than a bigger bass reflex cabinet?. Thank you.
Francesco.:blink:

[Fangio]

Welcome aboard. Tell us a bit more about the environment: application is HiFi, right? Room size, placement, favorite music, WAF etc. can play a role, as well as other options in amplification of course.

A D130 will probably need assistance for VLF, it's hard to get it lower than ~50Hz. Not sure if hornloaded cabinets will change that.

[Beowulf57]

My D130 is mounted in a back-loaded folded corner horn which loads the driver to 40Hz and rolls off at a rate of 12dB/octave below that frequency. I actually get measured usable response to 27.5Hz (lowest note on a concert grand piano). Posts 27 & 28 in this thread: http://audioheritage.org/vbulletin/showthread.php?t=20973&page=4 provide some information.

The D130 has a free air resonance of 40Hz and although I can't claim sub-woofer territory, it does just fine, even for pipe organ and home theatre. Yes, it rolls off below 40-50Hz.

[fracard.64]

thanks to Beowulf57 and Fangio. Fangio, I decided to move back from "commercial" hi fi (Harbeth, Klimo, Copland etc.) to high efficiency, only because I listened better (saving money...;)). I already had a Fisher KX200 from my father-in-law, that "resurrexit" the very moment I connected it to JBL! My favourite music ranges from classic, cameristica and baroque to jazz and contemporary. My room is 6mt.x4,00mt, 4,00 mt height, wood floor, brick and stones walls, with carpets, curtains and normal furnitures. My WAF is EXCELLENT:applaud:(cause my wife loves music too..) .
Beowulf, I remagnetized the D130 (and WOW... what a result!!) and the man measured the free air resonance in about 55 hz for one and 65 hz the other (the data claimed from JBL are optimistic IMHO). I'd be happy if I reach the 40hz or below :D. I tried a test CD for all the frequencies, but below the 40hz I could hear hardly anything. I viewed your fantastic speakers, I think they are some kind of a Hartsfield, which building - unfortunately - I can't afford; maybe the C34 or 4350 can give the same response results in low frequencies?
Thank you again.

[sba2]

"... I remagnetized the D130 (and WOW... what a result!!) and the man measured the free air resonance in about 55 hz for one and 65 hz the other (the data claimed from JBL are optimistic IMHO). I'd be happy if I reach the 40hz or below...

The fs on my two d130s are also above the published data--

43596

[Beowulf57]

I'm curious...what was the improvement you noticed after the D130 was re-magnetized?

fs specifications for the D130 varied from 37Hz-40Hz-55Hz across the years. The actual in use system in cabinet resonance (fc) will depend on the loading provided by the design. I don't know the differences between the D130 and the D130F (designed by JBL for Fender...I believe), but there are some for sure; the inductance of the coil is certainly not the same (even assunming the specs noted below, are for the D130F and not the D130, and I suspect the cone, surround and spider are also different. There is also the question of differences which may result from reconing?

Yes, I would expect the bass response to be very much affected by the cabinet and room placement. The C34, C40 (back-loaded folded horn), etc. might appreciably change the LF response.

The back-loaded folded corner horns I use provide excellent loading on the driver (the size of the horn mouth and the length of the horn is limited only by the dimensions of the room walls). I don't get sub-woofer bass and cannot reproduce 16Hz organ pedal notes (not much music gets down below 40Hz in any case) but I do get excellent bass impact and transient response which is more important to me than "special effects" bass.

You might also have room dimension nulls affecting the lower end and could experiment with placement, cabinet elevation to name a few. Do you use corner placement?

[BMWCCA]

I don't know the differences between the D130 and the D130F (designed by JBL for Fender...I believe), but there are some for sure; the inductance of the coil is certainly not the same (even assunming the specs noted below, are for the D130F and not the D130, and I suspect the cone, surround and spider are also different. Best I can recall, Harvey mentioned the only difference being a slightly larger voice-coil gap to prevent binding when the basket was over-torqued and twisted by the ham-fisted Fender speaker installers. :dont-know

[Beowulf57]

Best I can recall, Harvey mentioned the only difference being a slightly larger voice-coil gap to prevent binding when the basket was over-torqued and twisted by the ham-fisted Fender speaker installers. :dont-know

I love it! :applaud:

[fracard.64]

Since I read that Alnico degrades after 15/20 years, with loss in efficiency and my speakers are 30 years old, I decided to try. Believe me, the improvement isn't only on paper, but audibile: more sensitivity, efficiency, finally, more sound. In Italy there is only one firm that can do the work http://www.hiend.it/(with less than 15$ for each speaker). Now all the speakers measure more than 100db and are finally "pair":). Before the treatment the 075 were very different in terms of efficiency, cause Alnico degrades in different way for each speaker, depending upon multiple factors (heath, clima, amplification, use, etc...). But the different f.s. for the D130 remain. Unless they are originals, never reconed, the man (mr. Montagna) told me its rare to find a couple of that speaker with the same frequency response, cause the different rigidity of the cones, spider, surrounds, itself the fabric assembling can determine those differences.
I also read that there are not substantially differences bettween D130 and D130F. For the placement I can't use the corner, and a floor placement wasn't good (too bloomy and confused bass), so the speakers are now on a stand 50cm. height.

[Fangio]

My WAF is EXCELLENT:applaud:
A very italian answer.. :D

But seriously, not everyone here is allowed to put 4530's or C34's in their living room. ;) Congrats, carry on.


FWIW, I have a sort of pro 030 system with 075's & K130's so my interest in the thread topic is not only academic.

[Beowulf57]

Since I read that Alnico degrades after 15/20 years, with loss in efficiency and my speakers are 30 years old, I decided to try. Believe me, the improvement isn't only on paper, but audibile: more sensitivity, efficiency, finally, more sound. In Italy there is only one firm that can do the work http://www.hiend.it/(with less than 15$ for each speaker). Now all the speakers measure more than 100db and are finally "pair":). Before the treatment the 075 were very different in terms of efficiency, cause Alnico degrades in different way for each speaker, depending upon multiple factors (heath, clima, amplification, use, etc...). But the different f.s. for the D130 remain. Unless they are originals, never reconed, the man (mr. Montagna) told me its rare to find a couple of that speaker with the same frequency response, cause the different rigidity of the cones, spider, surrounds, itself the fabric assembling can determine those differences.
I also read that there are not substantially differences bettween D130 and D130F. For the placement I can't use the corner, and a floor placement wasn't good (too bloomy and confused bass), so the speakers are now on a stand 50cm. height.

Fascinating...my D130 and D131 are approximately 45 years old and have never been re-coned or re-magnetized. As well they have never been driven by more than about 25 watts of tube amplification. Actually the last time I checked to see what actual power was being drawn when I listened to music as loud as I ever do, it was around 2 watts. With the room loading provided by the folded corner horns that is enough to drive most people out of the room...even the house.

Having listened to the same speakers for so many years, it is quite possible that I do not notice any loss of sensitivity as it may have come on gradually. Certainly I have never noticed any sudden decrease in sensitivity or need for increased amplifier input. I used to listen in PP pentode/tetrode mode, but for the last 10 years have been solely in triode mode with directly heated triodes (6B4G) that provides around 15 watts...never needed anywhere near that much though.

What amplification are you using with your system? How much power do you apply to your speakers at the loudest levels?

The other indicator that might point to a slight loss of sensitivity in the bass drivers is that I have decreased the output on the LE85s roughly 2-3dB below the lowest and mid (see below for the reason the two different positions)setting on the LX5 crossovers (500Hz). This provides a more pleasing tonal balance between bass and midrange...but then again the D130/131 show a rising response into the midrange and I was not happy with the tonal balance when I tried the N1200 crossovers (1200Hz): Much too much midrange emphasis.

The D130 and D131 are specified to have a 2dB sensitivity difference and it is interesting that I set the LX5 at its lowest setting for the D131 and the mid setting for the D130. This provides a much more balanced bass/midrange similarity between the left and right channels.

I may consider re-magnetzing the drivers, but at the moment I can't notice any problem.

[fracard.64]

Beowulf, I wrote an answer that was a little novel, and the connection went down...I think God exist.
In summa summarum: I bought the speakers from a man who reputed the system having about 97db. During my first hearings it seemed to me less than what he declared and less what JBL claimed in technical data. I listened with an Fisher KX200 (36W, class A/B, with a normal negative feedback) and all seemed to me a little bit sluggish. Mr. Montagna isn't too far from my town and so....
Now I listen with the pre Klimo Merlino (not the best dynamic preamplfier) + Italian tube power amp (10W no-negative feedback, class A, using 8 Brimar CV4055 and two drivers G.E. 6189 N.O.S., one of the cleaner and dynamic amp I ever heard..). The result it's so better than before with the Fisher...However, I don't have any Vu meter, so I judge by the volume knob position: after remag i can't reach 09.30 if I don't want the Police arrest me and my wife...I think I don't use more than 4/5 watt to get down the house walls.
I was pushed to remagnetize by my first listening, so if you are satisfied you don't have to do nothing. The Xover is very simple and I just recapped it like "Baron030" teached in this forum: the higs, mids and Lf are in their place and they do a good job for me. Now the music lives and that's all.

[Beowulf57]

Beowulf, I wrote an answer that was a little novel, and the connection went down...I think God exist.
In summa summarum: I bought the speakers from a man who reputed the system having about 97db. During my first hearings it seemed to me less than what he declared and less what JBL claimed in technical data. I listened with an Fisher KX200 (36W, class A/B, with a normal negative feedback) and all seemed to me a little bit sluggish. Mr. Montagna isn't too far from my town and so....
Now I listen with the pre Klimo Merlino (not the best dynamic preamplfier) + Italian tube power amp (10W no-negative feedback, class A, using 8 Brimar CV4055 and two drivers G.E. 6189 N.O.S., one of the cleaner and dynamic amp I ever heard..). The result it's so better than before with the Fisher...However, I don't have any Vu meter, so I judge by the volume knob position: after remag i can't reach 09.30 if I don't want the Police arrest me and my wife...I think I don't use more than 4/5 watt to get down the house walls.
I was pushed to remagnetize by my first listening, so if you are satisfied you don't have to do nothing. The Xover is very simple and I just recapped it like "Baron030" teached in this forum: the higs, mids and Lf are in their place and they do a good job for me. Now the music lives and that's all.

D'accord! The soul of music is the final reason for all this work.

It is likely that my amplification system has quite a bit to do with my speakers' performance...no sluggish or muddy sound, but rather a clear rendering of harmonic textures, excellent dynamics from top to bottom and with a real enjoyment of instrumental timbres and character and the nuances of the musicians' interpretations. I think this has much to do with the monoblock Class A P-P triodes (about 12dB NFB), great Peerless output transformers and separate tube regulated power supplies. These power supplies made an enormous difference to the clarity, control and dynamics of the sound...no sagging B+ when large bass transients come along.

Sounds like a delightful Italian tube amp and like you are happy with your sound!

Amante della musica,

Douglas