DIY FRFR cab with Eminence BETA-12cx

Hello all...

Does anyone know the voltage of the 3.3uf cap that LZRBeam added in parallel (I PM'd him about it some days ago but haven't heard back)?

I have everything he described coming in the mail … except for the cap. I noticed there was different voltages when I went to buy it and I didn't want to get the wrong thing (does it even matter?).

Thanks in advance for any help
 
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<MACHINE> said:
Hello all...

Does anyone know the voltage of the 3.3uf cap that LZRBeam added in parallel (I PM'd him about it some days ago but haven't heard back)?

I have everything he described coming in the mail … except for the cap. I noticed there was different voltages when I went to buy it and I didn't want to get the wrong thing (does it even matter?).

Thanks in advance for any help
Click to expand...

Voltage ratings do matter, yes. Generally, use a capacitor rated at least twice the voltage than it'll be used for.
Can you see the part number or voltage rating of the already existing 3.3uf cap? Use an equivalently rated cap in parallel, should be fine.
 
Cool, thanks for the reply!
I did find a pic of the crossover but couldn't make out any numbers. When the unit arrives in the mail I'll take a look.
I actually did think to do that, but was trying to get the data before it arrived so I could pick one up (cap) locally and put it all together right away.
 
LZRBeam said:
Hi guys,

I've been working on a DIY FRFR cab project that turned out pretty nice so I wanted to share with everyone. I started with an empty single 12" cab from SEISMIC audio (Luke 1x12C). I loaded it with the BETA-12cx and the ASD:1001 horn. I used the eminence PXB2:2K5CX crossover. I did a simple modification to the high-pass section of the crossover by adding an additional 3.3uF cap in parallel with the existing 3.3 uF cap. That lowered the corner freq of the horn down from about 4 kHz to 3 kHz, and gave me a very close response to my ZLX-12P.

Cab $150
BETA-12cx $75
ADS1001 $30
Crossover $45
3.3uF cap $1.50

Great price for a nice FRFR system!

I did the last bit of EQ tweeking with the output GEQ of the AXE. The low-end was a little hot, so that was easy to fix. (This is a closed-back cabinet.)

It sounds great tilted back a bit, and has good dispersion.

View attachment 38960 View attachment 38961 View attachment 38962
Click to expand...
Thank you so much for share this informations.
Recently I post a Thread asking for this informations, because here (Brazil) I can't find an FRFR cab style to buy, so I want to build one!
Now I've got a new problem... find Eminence parts!
Thank you again!!
 
<MACHINE> said:
Cool, thanks for the reply!
I did find a pic of the crossover but couldn't make out any numbers. When the unit arrives in the mail I'll take a look.
I actually did think to do that, but was trying to get the data before it arrived so I could pick one up (cap) locally and put it all together right away.
Click to expand...
According to this picture, this cap is 250 VDC.
290-635_ALT_0.jpg
 
Yes ... I saw that, but the shipping price to Brazil is more than the sum of the 3 items, almost 250USD. In this case, I'm gonna look for this itens here!
 
Would this capacitor work: Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor? (sorry the board won't let me insert the link to the Parts Express website).

Also, to wire it in parallel, does one simply solder each lead of the capacitor it to each lead of the capacitor on the crossover board?
 
Furlan said:
Would this capacitor work: Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor? (sorry the board won't let me insert the link to the Parts Express website).

Also, to wire it in parallel, does one simply solder each lead of the capacitor it to each lead of the capacitor on the crossover board?
Click to expand...
Yes, and yes.

Make sure the second capacitor is attached in a mechanically sound manner before soldering it. The solder joint may fail if you are relying on it for mechanical strength, especially given the vibrations in a speaker cab. If there is space, try and wrap the capacitor leads around the leads on the original capacitor.
 
Furlan said:
Would this capacitor work: Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor? (sorry the board won't let me insert the link to the Parts Express website).

Also, to wire it in parallel, does one simply solder each lead of the capacitor it to each lead of the capacitor on the crossover board?
Click to expand...

That should do it.

To wire in parallel, yup, you can piggyback one cap to another. Either on top or on the side. Probably a good idea to use a glue gun to secure the new cap too, protect the solder joint against vibrations and whatnot. (Some capacitors have polarity, "head and tail" if you will. Doesn't look like the case here, but FYI.)

*usual disclaimer of, be safe and don't kill yourself with electricity, if you're not sure get someone who knows to do it.
 
Andy G said:
Yes, and yes.

Make sure the second capacitor is attached in a mechanically sound manner before soldering it. The solder joint may fail if you are relying on it for mechanical strength, especially given the vibrations in a speaker cab. If there is space, try and wrap the capacitor leads around the leads on the original capacitor.
Click to expand...

Thumbs up!
Something like this:
11-c-d-piggybacked-caps.jpg
 
To my ears, shifting the crossover to 3 kHz boosted the treble enough to eliminate the need to remove the pad.
 
LZRBeam said:
To my ears, shifting the crossover to 3 kHz boosted the treble enough to eliminate the need to remove the pad.
Click to expand...

So when you say "boosted the treble," are you talking about boosting 3~4kHz? Cus that seems relatively a small range to call "treble," so I'm confused as to what you're talking about.
 
The net-effect of moving the high-pass section of the crossover down from 4 kHz to 3 kHz provides a boost in the response between 3 and 4 kHz; and probably extends somewhat beyond 4 kHz; although I have no test data to prove that claim. I used my ears.
 
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