Hey all...
I have an old pair of B&O BEOVOX speakers that I'd like to compliment with a sub (or subs). However, I have size restraints -- 8" depth maximum.
I've found a design that looks promising: https://techtalk.parts-express.com/...mini-sub?238765-Voxel-a-mini-sub=#post1929280
Am thinking of maybe making two, to give sufficient SPL to match my speakers.
There's a bit of an issue however, which is that the above design does not include a crossover.
I don't know much about such things, but I do have another system which is a pair of JBL Control 5 paired with JBL SB-5 sub (all passive speakers). If I'm understanding correctly, the way this sub works is that the full range signal gets fed to the subs, then the crossover is a high pass which goes to the 'tops' or 'satellites'.
I could put a similar crossover in the design linked above, but what worries me is that there is no frequency adjustment in the enclosure design, i.e. the speaker is facing outward and will kick out frequencies all the way up to its maximum response (probably about 1.5khz).
The JBL sub has inward-facing speakers in a 'triple bandpass' design, so all it seems to kick out is stuff below the x-over frequency.
https://www.diyaudio.com/community/threads/jbl-control-sb5-modifications.390917/
so... wondering if anyone can suggest a design that would fit my 'compact' requirement but also satisfy my need for a crossover (aiming around 150hz... the BEOVOX fall off fairly sharply at 100hz)
I have an old pair of B&O BEOVOX speakers that I'd like to compliment with a sub (or subs). However, I have size restraints -- 8" depth maximum.
I've found a design that looks promising: https://techtalk.parts-express.com/...mini-sub?238765-Voxel-a-mini-sub=#post1929280
Am thinking of maybe making two, to give sufficient SPL to match my speakers.
There's a bit of an issue however, which is that the above design does not include a crossover.
I don't know much about such things, but I do have another system which is a pair of JBL Control 5 paired with JBL SB-5 sub (all passive speakers). If I'm understanding correctly, the way this sub works is that the full range signal gets fed to the subs, then the crossover is a high pass which goes to the 'tops' or 'satellites'.
I could put a similar crossover in the design linked above, but what worries me is that there is no frequency adjustment in the enclosure design, i.e. the speaker is facing outward and will kick out frequencies all the way up to its maximum response (probably about 1.5khz).
The JBL sub has inward-facing speakers in a 'triple bandpass' design, so all it seems to kick out is stuff below the x-over frequency.
https://www.diyaudio.com/community/threads/jbl-control-sb5-modifications.390917/
so... wondering if anyone can suggest a design that would fit my 'compact' requirement but also satisfy my need for a crossover (aiming around 150hz... the BEOVOX fall off fairly sharply at 100hz)
The thread implies a 2.1 channel amplifier was used. This would power the subwoofer and the satellites, with an active crossover built into the amplifier. Those are pretty common since active crossovers tend to work better at subwoofer frequencies, and passive crossover parts can cost more than an inexpensive 2.1 amp in some cases.
Here are a couple 2.1 channel amps at lower price points with decent ratings. There are more options out there.
https://www.parts-express.com/Lepai...-VDC-3A-120-VAC-Power-Supp-319-308?quantity=1
https://www.parts-express.com/Lepai...TPA3118-with-Power-Supply-310-4003?quantity=1
Here are a couple 2.1 channel amps at lower price points with decent ratings. There are more options out there.
https://www.parts-express.com/Lepai...-VDC-3A-120-VAC-Power-Supp-319-308?quantity=1
https://www.parts-express.com/Lepai...TPA3118-with-Power-Supply-310-4003?quantity=1
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The design you favour requires a separate amp with a line-level low-pass filter.
The JBL Sub-5 is a bandpass sub. It doesn't need a crossover. The driver receives a full range signal but only bass frequencies escape through the ports.
Depending on your amp any passive sub will need to be dual-coil, even so, you are likely to run into impedance problems.
Unless you specifically want to build the sub from scratch yourself, your design is typical of those found in dumpsters everywhere. Every discarded high-end computer speaker system or low-end home system theatre comes with a sub of similar specs.
The JBL Sub-5 is a bandpass sub. It doesn't need a crossover. The driver receives a full range signal but only bass frequencies escape through the ports.
Depending on your amp any passive sub will need to be dual-coil, even so, you are likely to run into impedance problems.
Unless you specifically want to build the sub from scratch yourself, your design is typical of those found in dumpsters everywhere. Every discarded high-end computer speaker system or low-end home system theatre comes with a sub of similar specs.
Thanks for the replies. At this point I'm actually wondering if buying something like this might be a better option: https://www.thomann.de/ie/ld_systems_sub_88.htm
I'm sure it will illicit many sniggers, but I'm in a very temporary situation at the moment in a static caravan. So, my speakers (B&O Beovox S30) will be up in the corners of the front room (the only place where there's any space), and I hope to 'hide' the sub behind a settee with the port facing upwards.
Just add insult to injury, my 'amp' will be the ubiquitous 4x35W car stereo... with 2x35w outputs driving the tops and the other 2x35w outputs in parallel to the sub.
Let the laughter ensue....
I'm sure it will illicit many sniggers, but I'm in a very temporary situation at the moment in a static caravan. So, my speakers (B&O Beovox S30) will be up in the corners of the front room (the only place where there's any space), and I hope to 'hide' the sub behind a settee with the port facing upwards.
Just add insult to injury, my 'amp' will be the ubiquitous 4x35W car stereo... with 2x35w outputs driving the tops and the other 2x35w outputs in parallel to the sub.
Let the laughter ensue....
I don't think anyone's going to laugh at you, where you are, or what you want to do. Everyone's at different places in their lives with different needs.
At lower price points, it gets hard to do much better than stuff you can buy off-the-shelf or used.
The model you referred to looks like a reasonable option. Bandpass boxes can leak some higher frequencies out of their ports, but it's not typically a problem in practice. Orienting the port away from the listeners can help, if that winds up being an issue.
As with most stereo purchases, if you can buy one from a place that allows for returns that would be best. If it does what you want, keep it and be happy. If it doesn't, reevaluate the approach with the new things you learned.
And let us know how it goes for your project, whichever way you go.
At lower price points, it gets hard to do much better than stuff you can buy off-the-shelf or used.
The model you referred to looks like a reasonable option. Bandpass boxes can leak some higher frequencies out of their ports, but it's not typically a problem in practice. Orienting the port away from the listeners can help, if that winds up being an issue.
As with most stereo purchases, if you can buy one from a place that allows for returns that would be best. If it does what you want, keep it and be happy. If it doesn't, reevaluate the approach with the new things you learned.
And let us know how it goes for your project, whichever way you go.
