DIY FRFR cab with Eminence BETA-12cx

LZRBeam said:
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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Ok, thanks for clarifying.
 
Interesting read. My question is why is the Eminence 2.5K crossover actually crossing at 4K? I have read a couple of folks actually used the 3.5K crossover (instead of 2.5k) to allow the 12" woofer to produce more of the guitar frequencies and therefore make the cab sound smoother. There is usually some trash around 3 to 3.2K in high gain patches, and the idea is to have the woofer deal with these frequencies rather than the HF driver. Also the Beta 12CX has a +6db peak right at these frequencies which could be bad or good depending on the crossover point chosen.
 
Plexi12xxx said:
Interesting read. My question is why is the Eminence 2.5K crossover actually crossing at 4K? I have read a couple of folks actually used the 3.5K crossover (instead of 2.5k) to allow the 12" woofer to produce more of the guitar frequencies and therefore make the cab sound smoother. There is usually some trash around 3 to 3.2K in high gain patches, and the idea is to have the woofer deal with these frequencies rather than the HF driver. Also the Beta 12CX has a +6db peak right at these frequencies which could be bad or good depending on the crossover point chosen.
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Maybe he measured at the 0 dB of corner? Hopefully the OP measured it at the -3 dB or -6 dB point of the tweeter, depending on the crossover design. There's component tolerances, but 2.5k to 4k seems a little too much variance...
 
Hmmm.... my basic xover understanding (i.e. I just Googled it) is this: adding that single capacitor does not "change the crossover point", it just lowers the high-pass frequency to the tweeter.

Using the values from the images, the PXB2.2k5 uses a low-pass at ~2k and high-pass at ~6k -- meaning the woofer is -12dB @4k and the tweeter is -12dB @3k so the 3-4dB overlap (i.e. between 3k and 4k) is going to give a smooth-ish transition. Adding the 3.3uF capacitor lowers the high-pass to the tweeter to ~3k, lowering the -12dB point down to 1.5k. The overlap is now greater (i.e. between 1.5k and 4k) and should introduce a noticeable bump in 2k-3k range, which could certainly be characterized as "more treble" for your average guitar signal.

But keep mind the "more treble" characterization would only be the PERCEPTION... it wouldn't change the overall frequency response at all above 4k or so.
 
benvigil said:
Hmmm.... my basic xover understanding (i.e. I just Googled it) is this: adding that single capacitor does not "change the crossover point", it just lowers the high-pass frequency to the tweeter.

Using the values from the images, the PXB2.2k5 uses a low-pass at ~2k and high-pass at ~6k -- meaning the woofer is -12dB @4k and the tweeter is -12dB @3k so the 3-4dB overlap (i.e. between 3k and 4k) is going to give a smooth-ish transition. Adding the 3.3uF capacitor lowers the high-pass to the tweeter to ~3k, lowering the -12dB point down to 1.5k. The overlap is now greater (i.e. between 1.5k and 4k) and should introduce a noticeable bump in 2k-3k range, which could certainly be characterized as "more treble" for your average guitar signal.

But keep mind the "more treble" characterization would only be the PERCEPTION... it wouldn't change the overall frequency response at all above 4k or so.
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I got a LP at 2800 and HP at 4200 based on the cap values but I have no idea what the inductor values are. I was toying with the idea of buying the Beta 12CX and ASD1001 to play around with. The crossover choice was always the sticky part. Definitely a trial and error approach as stated by the OP. Probably best to save the $50 cost on the xover and put it towards the $250 Dayton plate amp that Mic uses. You can spend $200 on the amp and have a bi-amped active xover setup.
 
Plexi12xxx said:
Probably best to save the $50 cost on the xover and put it towards the $250 Dayton plate amp that Mic uses. You can spend $200 on the amp and have a bi-amped active xover setup.
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Plus you've then got the DSP capabilities of the Dayton amp, which I believe aren't too difficult to program.
 
Nathan M. said:
What you have to take into consideration with the Dayton amps is that there are 4 of them each with a different active crossover which means you will need to select your driver setup first and match the amp to it. Ideally, a plate amp with a user adjustable crossover would be great, much more beneficial than all of the DSP modes provided.

I would imagine that if you are using the common Eminence Beta coax setup that you would use the Dayton amp with the 2.5K crossover, but maybe not.
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Yep. Too bad they don't have adjustable xovers. Ideally, one would need a test bench with a stereo amp and an active LP/HP and dial in a suitable frequency and slope. Or buy both the 2.5K and 3K and keep the best sounding one.
 
Plexi12xxx said:
Yep. Too bad they don't have adjustable xovers. Ideally, one would need a test bench with a stereo amp and an active LP/HP and dial in a suitable frequency and slope. Or buy both the 2.5K and 3K and keep the best sounding one.
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This never occurred to me... I actually have a DBX 223s 2/3-way Stereo Crossover I use to split to my subs. I could use that sucker to test this. :)
 
Plexi12xxx said:
Yep. Too bad they don't have adjustable xovers. Ideally, one would need a test bench with a stereo amp and an active LP/HP and dial in a suitable frequency and slope. Or buy both the 2.5K and 3K and keep the best sounding one.
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Well, their amp crossover is digital, ain't it? If it's DSP driven, and it's not too difficult to program like @Andy G says (which... I doubt haha), then it should be adjustable.
 
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
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How is the DIY speaker holding up?
 
Resurrecting this thread since I just finished a passive DIY build similar to the OP's. The cab is a 1x12 tweed/oxblood from SubZworld. Cannot say enough about the quality of the cab - both appearance and sound. I will order from them again.


1615667339555.png

The system is comprised of:
  • an Eminence Beta-12CX x 12" coaxial driver,
  • an Eminence AS1001 1" HF titanium horn driver , and a
  • PXB2:2K5CX 2-way crossover board
Couldn't be happier with the build. Sounds amazing through my FM3 and Fryette PS 2 amp.

FYI, I had included a 3uf cap with the order to lower the horn cutoff, but after playing through it for a few hours, I decided that it was not needed or desired.

Assembly took about 15 minutes to pop in the speakers, solder 4 wires and mount the board in the cab.

Parts were $186 shipped from Parts Express the cab was $266 shipped, so $452 total. Can knock $4 off for the cap since it is not needed IMO.
 
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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...
I've done similar last year but with Eminence Beta 12LTA Speakers.
Built 2 cabs and used Thiele/Smalls parameter design plan and built cabs completely self.
Sounding good..
Found 2 used speakers in very good, nearly new condition for 35€ each.
Costs per cab with tolex, and hardware about 70-80€.
Just bought a FRFR-112A from Harley Benton and done comparison with the 2 selfmade cabs... Nearly no EQing needed.
 
HereToday said:
Resurrecting this thread since I just finished a passive DIY build similar to the OP's. The cab is a 1x12 tweed/oxblood from SubZworld. Cannot say enough about the quality of the cab - both appearance and sound. I will order from them again.


View attachment 79974

The system is comprised of:
  • an Eminence Beta-12CX x 12" coaxial driver,
  • an Eminence AS1001 1" HF titanium horn driver , and a
  • PXB2:2K5CX 2-way crossover board
Couldn't be happier with the build. Sounds amazing through my FM3 and Fryette PS 2 amp.

FYI, I had included a 3uf cap with the order to lower the horn cutoff, but after playing through it for a few hours, I decided that it was not needed or desired.

Assembly took about 15 minutes to pop in the speakers, solder 4 wires and mount the board in the cab.

Parts were $186 shipped from Parts Express the cab was $266 shipped, so $452 total. Can knock $4 off for the cap since it is not needed IMO.
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Cab looks cool and like a decent deal maybe.
Where did you buy yours?
Only place I found was their Reverb shop, where it's $264.50 + $48.50 Shipping = $313, not that bad, but not $266 shipped.

Looks like the cab is built for a single 12", so you must have had to do a cutout for the horn, yes?

Don't suppose anyone's tried it with the F12-X200, have they?
If that happens to work out, only costs would be the cab and speaker.
 
Dave Merrill said:
Cab looks cool and like a decent deal maybe.
Where did you buy yours?
Only place I found was their Reverb shop, where it's $264.50 + $48.50 Shipping = $313, not that bad, but not $266 shipped.

Looks like the cab is built for a single 12", so you must have had to do a cutout for the horn, yes?

Don't suppose anyone's tried it with the F12-X200, have they?
If that happens to work out, only costs would be the cab and speaker.
Click to expand...
I bought it on Reverb 18 months ago. Welcome to inflation. At the time, I was going to order two. Wish I had!

The horn is integrated on the Eminence (coaxial). No cutout required.
 
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