Hi all,
I've had a pair of the Behringer B3030A monitors for a while, and I quite like them. They sound pretty full-range, nothing really missing, and go pretty loud for the size of the box. I quite like them.
Naturally, I dismantled them.
Everything looks pretty good:
- Sensible electronics (though I'm not particularly experienced in that area)
- Solidly built MDF cabinet, with reinforced baffle around the midbass driver, around 30mm thick there.
- Decent drivers
- Chunky speaker wires
A couple of things I did note that might be improved upon:
- No internal bracing
- The 6" midbass driver has a fairly narrow window to the back of the cone, and the extra-thick baffle means I can barely get a finger to the cone.
- Connectivity. It would be nice to be able to connect a 3.5mm jack cable and play music, instead of messing around with XLR devices.
Note that I'm not going to advocate swapping drivers, cables, capacitors etc. There are better ways to spend money than a pair of esoteric capacitors with no measurable benefits. Some good whiskey has much a much better price to performance ratio.
Swapping drivers out is also a no-no. This particular driver complement demands a higher-than-usual crossover point, and dropping in a different set of drivers would mean a re-design of the crossover. You might as well just start from scratch.
So, on to the mods...
The slot ports go down the sides of the cabinet, exiting near the bottom inside, so cross-bracing the sides is difficult. However, it's easy to brace between the baffle and back panel. I used a 1.5" wide strip of 18mm plywood. Cut to about 133mm long, it wedges in nicely. Generous quantities of PVA secured it. The top and bottom panels have some extra blocks around the edges for support, and the midbass driver's shielded magnet is quite large, so I didn't bother bracing that way.
Next up, I took a sharp knife to the cabinet, and cut away a rough chamfer around the midbass driver. This took quite a while since the material is quite thick. Sandpaper smoothed it out with a slight round-over. Afterwards, I could easily get two fingers to the back of the cone, so airflow has been improved. Since the woofer is running quite high (3.4kHz), that'll reduce midrange reflections, too.
Lastly, connectivity. I've drilled a pair of holes in the bottom of each amplifier. On each speaker there'll be...
1x 3.5mm jack socket (input)
1x 6.35mm jack socket (output)
One side of the 3.5mm input goes to the input stage on the amplifier (or just to a couple of the XLR pins). The other channel goes to the new 6.35mm jack socket, which will act as an output to feed to the other speaker via a guitar cable.
With that installed on both speakers, either will be able to be used as the master speaker and feed out to the other one. I think the left speaker will be the master (personal preference), so the right channel of the 3.5mm input will go straight to the output jack.
I'm waiting on the connectors arriving so I haven't done that bit yet. As for the rest, I can say the sound has improved a little. There was some gain at the low end, to a point where I've had to use the LF rolloff switch to tame it a little. Hey, free headroom.
I haven't noticed any epiphany-like improvement to the sound. I think perhaps transients are a little sharper, but I could be fooling myself.
The improvements suggested probably make things better, and certainly don't make things worse. It's also cured the itch to open these up and see what can be done with them.
Cheers,
Chris
I've had a pair of the Behringer B3030A monitors for a while, and I quite like them. They sound pretty full-range, nothing really missing, and go pretty loud for the size of the box. I quite like them.
Naturally, I dismantled them.
Everything looks pretty good:
- Sensible electronics (though I'm not particularly experienced in that area)
- Solidly built MDF cabinet, with reinforced baffle around the midbass driver, around 30mm thick there.
- Decent drivers
- Chunky speaker wires
A couple of things I did note that might be improved upon:
- No internal bracing
- The 6" midbass driver has a fairly narrow window to the back of the cone, and the extra-thick baffle means I can barely get a finger to the cone.
- Connectivity. It would be nice to be able to connect a 3.5mm jack cable and play music, instead of messing around with XLR devices.
Note that I'm not going to advocate swapping drivers, cables, capacitors etc. There are better ways to spend money than a pair of esoteric capacitors with no measurable benefits. Some good whiskey has much a much better price to performance ratio.
Swapping drivers out is also a no-no. This particular driver complement demands a higher-than-usual crossover point, and dropping in a different set of drivers would mean a re-design of the crossover. You might as well just start from scratch.
So, on to the mods...
The slot ports go down the sides of the cabinet, exiting near the bottom inside, so cross-bracing the sides is difficult. However, it's easy to brace between the baffle and back panel. I used a 1.5" wide strip of 18mm plywood. Cut to about 133mm long, it wedges in nicely. Generous quantities of PVA secured it. The top and bottom panels have some extra blocks around the edges for support, and the midbass driver's shielded magnet is quite large, so I didn't bother bracing that way.
Next up, I took a sharp knife to the cabinet, and cut away a rough chamfer around the midbass driver. This took quite a while since the material is quite thick. Sandpaper smoothed it out with a slight round-over. Afterwards, I could easily get two fingers to the back of the cone, so airflow has been improved. Since the woofer is running quite high (3.4kHz), that'll reduce midrange reflections, too.
Lastly, connectivity. I've drilled a pair of holes in the bottom of each amplifier. On each speaker there'll be...
1x 3.5mm jack socket (input)
1x 6.35mm jack socket (output)
One side of the 3.5mm input goes to the input stage on the amplifier (or just to a couple of the XLR pins). The other channel goes to the new 6.35mm jack socket, which will act as an output to feed to the other speaker via a guitar cable.
With that installed on both speakers, either will be able to be used as the master speaker and feed out to the other one. I think the left speaker will be the master (personal preference), so the right channel of the 3.5mm input will go straight to the output jack.
I'm waiting on the connectors arriving so I haven't done that bit yet. As for the rest, I can say the sound has improved a little. There was some gain at the low end, to a point where I've had to use the LF rolloff switch to tame it a little. Hey, free headroom.
I haven't noticed any epiphany-like improvement to the sound. I think perhaps transients are a little sharper, but I could be fooling myself.
The improvements suggested probably make things better, and certainly don't make things worse. It's also cured the itch to open these up and see what can be done with them.
Cheers,
Chris
Nope, I stopped there. The results were decent, although there's the inevitable directivity mis-match that happens when you cross a 6.5" driver at 3.4kHz.
I ended up selling them to a fellow HiFi person, who wanted a decent pair of active speakers for a second room. The mods I implemented meant it was very easy to plug in a device and enjoy the music.
These days, I've built a pair of 8" 2-way speakers with compression drivers, passive crossover around 950Hz. Driven by an easy-to-use amplifier and digital source, they sound excellent.
Chris
I ended up selling them to a fellow HiFi person, who wanted a decent pair of active speakers for a second room. The mods I implemented meant it was very easy to plug in a device and enjoy the music.
These days, I've built a pair of 8" 2-way speakers with compression drivers, passive crossover around 950Hz. Driven by an easy-to-use amplifier and digital source, they sound excellent.
Chris
Bit of a write-up here: FIR Processing | grimshaw-audio
Including some measurements and how I used FIR filtering to flatten the phase shifts caused by the passive crossover.
I need to re-do them with proper wood - the 12mm ply from the local chain hardware store is low-quality and warped. Fortunately, I know where I can get good 18mm birch ply, so that's a project on the list.
There are a few directions I'm interested in exploring with this concept:
- Higher-end drivers - Seas Excel, and one of the latest 1" HF drivers
- More LF drivers - The HF driver has a very easy time in these speakers, with approx 20dB of attenuation in-line. Moving to 4x 8" drivers would increase voltage sensitivity (especially if I got silly and wired for 2ohm - not applicable with the current amplifier) and decrease LF distortion. Maybe go to a 2.5-way MTMWW.
However, my income has been near-completely wiped out by the virus, so HiFi projects are on pause for now. That's okay, though. The system sounds excellent and gets used in one way or another for about 10 hours per day.
Chris
Including some measurements and how I used FIR filtering to flatten the phase shifts caused by the passive crossover.
I need to re-do them with proper wood - the 12mm ply from the local chain hardware store is low-quality and warped. Fortunately, I know where I can get good 18mm birch ply, so that's a project on the list.
There are a few directions I'm interested in exploring with this concept:
- Higher-end drivers - Seas Excel, and one of the latest 1" HF drivers
- More LF drivers - The HF driver has a very easy time in these speakers, with approx 20dB of attenuation in-line. Moving to 4x 8" drivers would increase voltage sensitivity (especially if I got silly and wired for 2ohm - not applicable with the current amplifier) and decrease LF distortion. Maybe go to a 2.5-way MTMWW.
However, my income has been near-completely wiped out by the virus, so HiFi projects are on pause for now. That's okay, though. The system sounds excellent and gets used in one way or another for about 10 hours per day.
Chris
By all means.
I've got a few options available to me but I seem to heading down the "'there's no replacement for displacement" path? Have a Faital pro 15" mocking me everyday for not sticking it in an enclosure yet.
My biggest weakness is the software side of things. I've got a mini dsp and dsp hd, still trying to get my head around fir, phase linearity, gated measurements and all the rest of it
I've got a few options available to me but I seem to heading down the "'there's no replacement for displacement" path? Have a Faital pro 15" mocking me everyday for not sticking it in an enclosure yet.
My biggest weakness is the software side of things. I've got a mini dsp and dsp hd, still trying to get my head around fir, phase linearity, gated measurements and all the rest of it
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