how to improve my sytem

[Klaus]

Hey everybody

My cabinets are about 20 years old and i would like to start a new DIY-project.

My set up:
2235 H
2118 J
2404 H
Amcron 1201

They sound loud and powerfull but i would like more low end and more hifisound. Should i go with two 2235 H per new cabinet and replace the 2118 J or the 2404 H and biamp them ?

Any idea?
Thanks for your help
Regards

Klaus

[Alex Lancaster]

Is the picture upside down?, if not, put the woofers on the bottom.

[boputnam]

Hey, Klaus... :wave:

Great idea to put this to the Forum! ;)

Alex is right - you should get better imaging with the HF closer to ear-level. That will bring more HiFi sound.

What is the interior dimension of that cabinet (less the interior volume of the 2118 subenclosure)?

What is the port tuning?

What network are you using?

[Klaus]

Originally posted by boputnam
Hey, Klaus... :wave:

Great idea to put this to the Forum! ;)

Alex is right - you should get better imaging with the HF closer to ear-level. That will bring more HiFi sound.

What is the interior dimension of that cabinet (less the interior volume of the 2118 subenclosure)?

What is the port tuning?

What network are you using?


The interior volume is 5,3 cf. Subenclosure 0,5 cf
The port : 3,94 X 3,94 X 5,51
The network is DIY. Unfortunately i do not know much about it.
Thanks
Klaus

[Ian Mackenzie]

Klaus,

Sounds like you have a well engineered system, I recall kits marketed by Goldsound in the USA using similar components.

You could try bi amping the system after the 2118 crossover point to extend the performance or better capacitors in the passive crossover.

Alternatively, if you were to lay the system on its side with some low profile stands you could add a mid range horn on top like a 2397 (see the Library for alternatives) between 1200 - 8000 hertz and upgrade the crossover network.

This would sharpen up the clarity of the system and make it more of the classic 43xx vintage.

Another idea is to replace the 2404 with the 2344A/2426 driver, again crossing over around 1000-1200 hertz, the 2344a has found favour among our most senior members.

If you check out the Widgets 4355 thread he has the horn resting in the top of the enclosure.

I expect you would find this an advantagous way to start a new diy project with your existing system.

Ian

[boputnam]

Originally posted by Ian Mackenzie
...I recall kits marketed by Goldsound in the USA using similar components. Well done, Aussie!! :yes:

Gold Sound Kit 11 (http://www.goldsound.net/kit11.htm)

Notice they cross at 300Hz and 5,000Hz...

I'd say you're on to something, Klauss. Notice the orientation of the cabinet, and the "reviews"... :thmbsup:

Gold Sound Link (http://www.goldsound.net/home.htm)

[Robh3606]

Hello Klaus

That's a nice set up. Should kick. I would take a look at the Gold kit posted, reorient the drivers into an offset vetical array and see what's up with the crossover and tunning on the box. You have dimensions and depth on the port so we can get an idea where the box is tunned??

Rob:)

[Klaus]

Originally posted by Robh3606
Hello Klaus

That's a nice set up. Should kick. I would take a look at the Gold kit posted, reorient the drivers into an offset vetical array and see what's up with the crossover and tunning on the box. You have dimensions and depth on the port so we can get an idea where the box is tunned??

Rob:)

Thank you all for your help.

Interior volume is 5,3 cf. Subenclosure 0,5 cf
The ports : 3,94 X 3,94 X 5,51
What about two 2235 H per cabinet?

Regards Klaus

[Guido]

Hi Klaus!

This is what I got in BB6. Looks good!

For me this sounds like a xover Prob.

Could you show us a pic of the xover?

[Klaus]

Originally posted by Guido
Hi Klaus!

This is what I got in BB6. Looks good!

For me this sounds like a xover Prob.

Could you show us a pic of the xover?

Hey Guido

The pic from the xover comes soon. I have to open the cabinet.:bomb:

Klaus

[Klaus]

Originally posted by Klaus
Hey Guido

The pic from the xover comes soon. I have to open the cabinet.:bomb:

Klaus

[boputnam]

Originally posted by Robh3606
You have dimensions and depth on the port so we can get an idea where the box is tuned?? Here's what my run at BBPro tells me - Fb is 29.6Hz.

I've assumed:

Net volume = 4.8ft3 (net of sub-enclosure)
Damping = "Typical" (cabinet walls, none on baffle)
QL = 7
QLv is default (not specified)

[boputnam]

Venting:

[boputnam]

Originally posted by Guido
This is what I got in BB6. Looks good! Hey, Guido...

What Fb did your run yield...? :hmm:

[Ian Mackenzie]

The crossover looks okay for a production unit.

The 2nd crossover point is a stretch for both the midrange and tweeter, this is where you can amend the design by adding a horn and driver.

The guys can help you out with the re work on the crossover.

If you seriously wont to play with different kinds of drivers consider an electronic crossover unit. Robs system is setup like this, ask him for details. You could then use an upper midrang dome like the 093 and a dome tweeter like the 035/055/066...very hifi.... without having to consider matching driver sensitivity as you do in a passive crossover.

The system will give differing bass response pending position in the room as configured, better to have lesser bass than boom.

Where are your Boxes located? The repositioning the boxes.
What sort of amplifier are you using?

The thing about JBL is you can always add a little bass in with an Equaliser or tone controls to extend the bottom end.

Ian

[Guido]

Originally posted by boputnam
Hey, Guido...

What Fb did your run yield...? :hmm:

Bo I ended up with

Fb 31,05 Hz

[Guido]

Klaus, can you name the values on the xover parts?

Maybe you can draw a schematic?

Then we will maybe be able to improve the system

[Klaus]

Thanks Alex, Bo, Ian, Robh2306 and Guido for your help.

Analysing your answers the problems are:

Orientation of the speakers

Replace the MF and HF speakers ?

Xoverproblems:

Sorry i think the xover is a DIY project. On most of the parts are no numbers.
:confused:

Here is a closer look of the inner section of the cabinet.

Klaus

[Klaus]

sorry here is the pic

[Guido]

One can see that the original speaker mounting holes are still there.

Other interesting thing is that you have a K140 reconed to 2235H.

[Klaus]

Originally posted by Guido
One can see that the original speaker mounting holes are still there.

Other interesting thing is that you have a K140 reconed to 2235H.
Hey Guido

The speakers are mounted in this cabinet only to test the soundquality.

Oh yes my 2235 H are reconed K 140. Is this a problem ? (minor quality)

Thanks
Klaus

[boputnam]

Originally posted by Klaus
sorry here is the pic Hey, Klaus...

You need to put batting (fiberglass wool) on ALL sides of the cabinet, and the back. You should cover the bracing, and network housing, too.

This is very important.


Also, with all that modification to the baffle (from different transducer mountings...), you might not have good airtight. Have you glued all those pieces in-place so they are airtight...?

[Ian Mackenzie]

Good idea to test for leaks as Bo's says...our official "fart master".

Use and audio sinewave if available


Ian

[Mr. Widget]

Originally posted by Klaus


They sound loud and powerfull but i would like more low end and more hifisound. Should i go with two 2235 H per new cabinet and replace the 2118 J or the 2404 H and biamp them ?



You should be able to get plenty of deep bass from that woofer in those cabinets. You may need to push them up to a wall or into corners to get the lowest bit out of them. Short of adding EQ to the system to boost the bass, you're apparent lack of bass may be due to the relative driver to driver balance. You may want to explore lowering the output of your mid bass driver a bit.

More importantly, looking at your system, there is an obvious lack of an actual midrange. Taking the 8" mid bass driver up to 5KHz is really pushing it. I think if you were to add a 1" or 2" compression driver with an appropriate horn it will improve your system in two ways. First it will give you a significantly more detailed midrange with better dispersion, and second, it will afford you greater flexibility in voicing the system.

All in all, I think you have a good start there.

Widget

[Klaus]

More importantly, looking at your system, there is an obvious lack of an actual midrange. Taking the 8" mid bass driver up to 5KHz is really pushing it. I think if you were to add a 1" or 2" compression driver with an appropriate horn it will improve your system in two ways. First it will give you a significantly more detailed midrange with better dispersion, and second, it will afford you greater flexibility in voicing the system.


Please give me more information about the driver/ horn system.

Thanks
Klaus

[Mr. Widget]

Originally posted by Klaus



Please give me more information about the driver/ horn system.

Thanks
Klaus


There are so many to choose from, I don't know where to begin. There are of course economic considerations as well as personal taste.

You might look at the 2344A horn with a 2421, 2425, or 2426 driver. This type of horn is designed for constant directivity so the on axis response falls off as frequency goes up. This requires a crossover with built in EQ or it requires an out board EQ circuit or equalizer.

You can use a tractrix horn like an Edgar salad bowl with any of those drivers. It would be simpler to implement since it's response doesn't require an external EQ.

A third more costly solution both in terms of cost and physical space would be a 2441 or 2445 driver on a 2397 diffraction horn.

All three of these options while being quite different from one another could be added to your system to produce excellent results.

Widget

[Robh3606]

Before you go down the road of adding a compression driver I would look up the 4612 techsheet to see how JBL set-up the crossovers. That box uses 2 2118J's and a 2404. One 2118 runs fullrange the other is lowpassed with a simple crossover on the 2404. Driver ballace could very well be you problem. I would work with what you have and get it tweeked the best you can then think about dropping in a compression driver.

http://www.jblproservice.com/pdf/Cabaret%20Series/4612B.pdf


Rob:)

[4313B]

Originally posted by Robh3606
Driver balance could very well be you problem.Absolutely. You might also want to contact Ron Gold and see how he did his passive filters.

[Guido]

Originally posted by Giskard
Absolutely. You might also want to contact Ron Gold and see how he did his passive filters.

Yep! Perfect Idea!

It is nearly a Ron Gold design you have.

[Klaus]

Thank you all for your great help.
Klaus