Jack build European material

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Bill Fitzmaurice
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Re: Jack build European material

#16 Post by Bill Fitzmaurice » Sat Sep 25, 2021 3:43 pm

Jean Mi wrote:
Sat Sep 25, 2021 2:19 pm
1 no tweeter, 1 low tweeter (4 ohm resistance in serial on the high pass filter input), 1 full tweeter (direct input on the high pass filter
If you're saying what I think you're saying don't do that. There is a 4 ohm resistor in the high pass filter. Another 4 ohm resistor in series with it will have no effect.

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Seth
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Re: Jack build European material

#17 Post by Seth » Sat Sep 25, 2021 9:32 pm

Jean Mi wrote:
Sat Sep 25, 2021 2:19 pm
Hey Guys

I am close to finish (I take my time) I finaly order the Caps

Find some pictures of the work

I machine the rear panel to add the speakon connectors plate

Image

Some electrical circuit test (I build it with a 3 way switch : 1 no tweeter, 1 low tweeter (4 ohm resistance in serial on the high pass filter input), 1 full tweeter (direct input on the high pass filter)
I use mastic (sifka 1FC to seal the speakons)
Image

Focus on the circuit (low pass and high pass)
21092509042626040617587407.jpg
Final rear panel with insulation
21092509042826040617587408.jpg

I also glue washers to avoid to stamp to seal screwing the panel on the main case
21092509052926040617587410.jpg
Picture of the main case with insulation (you can see the connector to connect the circuit to the tweeters)
21092509042926040617587409.jpg
Then I do the leak test and the burn in test (30h 30hz)
21092509053626040617587415.jpg
My jack almost finished (I just to add the final wood sheet, I have to do it again cause first time I have a problem with the glue and the wood sheet cause the wood sheet makes waves when glue was dry, so I bought other one directly with adesive on the rear..)
21092509053826040617587416.jpg
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Jean Mi
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Re: Jack build European material

#18 Post by Jean Mi » Tue Nov 02, 2021 3:23 pm

Bill Fitzmaurice wrote:
Sat Sep 25, 2021 3:43 pm
Jean Mi wrote:
Sat Sep 25, 2021 2:19 pm
1 no tweeter, 1 low tweeter (4 ohm resistance in serial on the high pass filter input), 1 full tweeter (direct input on the high pass filter
If you're saying what I think you're saying don't do that. There is a 4 ohm resistor in the high pass filter. Another 4 ohm resistor in series with it will have no effect.
Here the scheme of what I have done (it is what I understand from the explanations :" . If the array sounds overly bright place the 4 ohm resistor between the jack connection and the 5.6uF capacitor, which reduces sensitivity by 2dB"

Image

In fact the switch is a 3 way one. First position full Tweeter (4ohm resistor is shunted) ; midle position all tweeters off ; second position tweeter -2dB.

The difference between the 3 positions can be really heard (with normal music, I cannot see any diffrence playing bass even slapping on the D string)

Jean Mi
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Re: Jack build European material

#19 Post by Jean Mi » Tue Nov 02, 2021 3:30 pm

In other hand ,

I finalize the jack

As said before I use marpple wood sheet then I had corners and handle

Image
https://nsm09.casimages.com/img/2021/11 ... 651298.jpg



Image
https://nsm09.casimages.com/img/2021/11 ... 651302.jpg

Image
https://nsm09.casimages.com/img/2021/11 ... 651301.jpg

Image


Regarding the sound. I was very surprised. The sound is very neutral it gives you back the sound of the source (if the source is bad or unbalanced the jack will give it to you as it is) . First I thought "there is no bass" but when I adjust the balance to the low and push the volume it seems to have no limit. So I am really happy of it now !

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Tom Smit
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Re: Jack build European material

#20 Post by Tom Smit » Tue Nov 02, 2021 9:38 pm

:clap:
TomS

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Seth
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Re: Jack build European material

#21 Post by Seth » Wed Nov 03, 2021 11:40 pm

Jean, that came out looking real nice. Good job :thumbsup: I'm glad you're happy with the results.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Jean Mi
Posts: 14
Joined: Mon Apr 05, 2021 1:36 pm

Re: Jack build European material

#22 Post by Jean Mi » Tue Nov 09, 2021 10:08 am

Hey Guys,

I am in trouble, when I push the sound a lot with lot of low frequencies, I can heard parasite noises like "BZZZZ". I will check the cable tight and the crossover plate if I can add stiffer fixation... May you have other ideas of what can give those parasite noises ?

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Seth
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Re: Jack build European material

#23 Post by Seth » Tue Nov 09, 2021 10:25 am

Jean Mi wrote:
Tue Nov 09, 2021 10:08 am
Hey Guys,

I am in trouble, when I push the sound a lot with lot of low frequencies, I can heard parasite noises like "BZZZZ". I will check the cable tight and the crossover plate if I can add stiffer fixation... May you have other ideas of what can give those parasite noises ?
Not always, but a lot of times the issue isn't the cab. Before you spend too much time tearing into the cab looking for loose stuff, put a new battery in your bass, try a different amplifier, a different cable. If there's no improvement and the noise persists, try isolating and locating the noise by listening through a hose/tube while probing around the cab.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Bruce Weldy
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Location: New Braunfels, TX

Re: Jack build European material

#24 Post by Bruce Weldy » Tue Nov 09, 2021 11:13 am

Jean Mi wrote:
Tue Nov 09, 2021 10:08 am

when I push the sound a lot with lot of low frequencies, I can heard parasite noises like "BZZZZ".
It could be several things, but if you are "pushing the sound a lot with lot of low frequencies" by turning up the bass on the amp - try turning the bass knob down and just increase the volume. Turning up the bass knob almost always creates a crappy tone and adds too much excursion in the driver.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

howiez
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Re: Jack build European material

#25 Post by howiez » Tue Nov 09, 2021 8:32 pm

Very nice!

Jean Mi
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Re: Jack build European material

#26 Post by Jean Mi » Thu Nov 11, 2021 7:00 am

Thanks, I will try this weekend, I am aslo not 100% sure it came from the cab cause I plug my headphone instead the cab with same adjustement and I can heard the same kind of parasite sound. My bass is passive one, I will try with another one and also with sound from aux input to see...

Jean Mi
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Re: Jack build European material

#27 Post by Jean Mi » Fri Nov 12, 2021 10:25 am

I try today, It is strange. I use aux in and I push the volume, sound was lound and clear (through TC ELECTRONICS BQ250)
Then I try with 2 bass, the only difference was the output power of the bass but with the same final sound level I have the same effect.
In fact it sounds more like overdrive rather than BUZZ , rather than if something was saturating... I will try with direct output to the driver (without cross over, maybe something wrong in it...)
With the TC ELECTRONICS BQ250 it start to happen when gain the middle and master 1/3... (With or without compressor)
I also try to feel the driver moves, I put my fingers rougly 5 mm far from the static position and the membrane never tought my fingers...

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Seth
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Re: Jack build European material

#28 Post by Seth » Fri Nov 12, 2021 11:02 am

Jean, if you're hearing it in your headphones too, it's not the cab. Seems like the signal is getting clipped in the amplifier portion of the BQ250, likely the input (post EQ section) since you're hearing it in headphones too. Something along those lines. That is, if you're absolutely 100% sure your bass pickups are passive. Have you tried it with the passive/active switch on "active"? Same result?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Jean Mi
Posts: 14
Joined: Mon Apr 05, 2021 1:36 pm

Re: Jack build European material

#29 Post by Jean Mi » Sun Nov 14, 2021 3:24 pm

Seth, Thanks for your feeb back, you are true I try again with my headphones and at the same level of Gain and Master switches position I have the same result. So it is not from the Jack ! but from BQ250.
I try to change the passive/active input switch, the output level reduce a bit but if I turn switches to have the same output level I have the same saturation... same when I play with the BQ250 compressor. I will see with BQ250 users to see if the behaviour is same...

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Bill Fitzmaurice
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Re: Jack build European material

#30 Post by Bill Fitzmaurice » Sun Nov 14, 2021 4:24 pm

Put the master at full, use the gain to control the volume.

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