I'm looking to design a portable (backpack) speaker. This will be a two-way speaker with DSP, and I'm trying to figure out how to do the subwoofer part. The volume occupied by the subwoofer part would be around 12 to 15 liters. As for characteristics, I want the subwoofer to be more or less flat down to 35 Hz if possible, so deep rather than boomy. As for power, somewhere in between 70 and 150W is my ballpark.
A 4 ohm driver would be ideal as my amplifier can only push around 70-80W into 8 ohm speakers, but 8 ohm could be justifiable if a really nice driver is available. As for budget, around €80 max for the driver would be ideal (I might build 2 for stereo). I'm a newbie to subwoofer design, but from what I've gathered, drivers for compact designs benefit from low Vas, low Fs, low Qts, and high Xmax. With this in mind I combed though the SoundImports catalog and made a spreadsheet of every woofer within that budget range (see attachment). The most promising contenders I found were the Peerless by Tymphany SLS-P830946 and the Dayton Audio DCS165-4. I couldn't find a good 8 ohm contender.
As for the type of enclosure, I was thinking of either a folded transmission line speaker or passive radiators.
I could use some wisdom here. If someone could point me in the right direction or provide some resources I would appreciate that.
A 4 ohm driver would be ideal as my amplifier can only push around 70-80W into 8 ohm speakers, but 8 ohm could be justifiable if a really nice driver is available. As for budget, around €80 max for the driver would be ideal (I might build 2 for stereo). I'm a newbie to subwoofer design, but from what I've gathered, drivers for compact designs benefit from low Vas, low Fs, low Qts, and high Xmax. With this in mind I combed though the SoundImports catalog and made a spreadsheet of every woofer within that budget range (see attachment). The most promising contenders I found were the Peerless by Tymphany SLS-P830946 and the Dayton Audio DCS165-4. I couldn't find a good 8 ohm contender.
As for the type of enclosure, I was thinking of either a folded transmission line speaker or passive radiators.
I could use some wisdom here. If someone could point me in the right direction or provide some resources I would appreciate that.
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Is it for a party crowd situation or personal use only?
I would suggest that you'll struggle to get high output and low bass in such a small enclosure, and you'll need to balance compromises depending on intended use
I would suggest that you'll struggle to get high output and low bass in such a small enclosure, and you'll need to balance compromises depending on intended use
In that small of an enclosure, a TL is probably out of the question.
A PR design is a bit more feasible, but 12~15 liters is a bit small to do down to 35 Hz with any authority, particularly outdoors. The DCS165-4 is a decent start - I've got the 8" version in an MLTL that I still use. If you want to move more air, look at one of the Tang Band options, like the W6-1139SIF or the neo magnet version.
A PR design is a bit more feasible, but 12~15 liters is a bit small to do down to 35 Hz with any authority, particularly outdoors. The DCS165-4 is a decent start - I've got the 8" version in an MLTL that I still use. If you want to move more air, look at one of the Tang Band options, like the W6-1139SIF or the neo magnet version.
Thank you for your reponse.
A folded transmission line of 2m with a cross section of 25cm² occupies 5 liters, excluding the walls. The cross section can be doubled and it's still only 10 liters. Is this not enough?
That's only 50W. Is this worth it?
You might experiencing some difficulties trying to fit a driver into a path with a cross-section of only 50 cm^2. It will have to be at least around 17 cm wide to accommodate the 6.5" driver's width, which means that it can only be 3 cm (1.15") deep. Most 6.5" drivers gave larger mounting depths 🙂.
I haven't personally used the Tang Band drivers, but I've heard good things about them.
I haven't personally used the Tang Band drivers, but I've heard good things about them.
I'm not sure I understand. I was thinking of doing something similar to what DIY Perks did in this video.
Yeah, I wouldn't call that TL. At least not a TL designed by the modern techniques used these days.