Bucket sub opinions?

[GM]

Has any 3rd party verified this design as "essentially flat from 25 Hz to 100Hz". Seems far fetched for a 8" in just under 19L, without EQ. PE lists a F3 of 58Hz in a slightly larger sealed enclosure. Modeling it in winisd and bassbox6, 25hz is at -16db, doesn't seem like room gain can account for that. I'm also showing a peak around 60-70hz, so not really flat.

None I could find.

Yeah, simmed it in HR [more like 15 L] and it doesn't support ANY of its performance claims plus doubt this 90 W cont. Peerless can handle Several hundred watts transients in the LF.

Still, with the massively high power, low Vas sub woofers + relatively cheap digital EQ, etc., available nowadays it's certainly an excellent value design if you want easy to build and its looks doesn't make it a non-starter.

GM

 

[bigx5murf]

None I could find.

Yeah, simmed it in HR [more like 15 L] and it doesn't support ANY of its performance claims plus doubt this 90 W cont. Peerless can handle Several hundred watts transients in the LF.

Still, with the massively high power, low Vas sub woofers + relatively cheap digital EQ, etc., available nowadays it's certainly an excellent value design if you want easy to build and its looks doesn't make it a non-starter.

GM

That's what I've found, and I'll admit I'm very new to simulating sub performance.

I brought this up on another forum, and the pitch forks came out. With everyone saying I shouldn't question the claims because the designer has forgotten more about speaker design than I'll ever know.

 

[GM]

'Sounds' like a good place to avoid if interested in learning the technical side of the 'art' of audio system design. Which one was it BTW?

GM

 

[bigx5murf]

'Sounds' like a good place to avoid if interested in learning the technical side of the 'art' of audio system design. Which one was it BTW?

GM

It was audiokarma, someone there is making claims that the cylindrical enclosure can't be modeled, or that changing the volume by 1 liter or less changes everything. I'm sure it's only a matter of time before he claims it needs the right brand of concrete or right screw finish.

The closets I could find was this guy's build, with a few small changes.

DIY Home Depot Bucket Subwoofer - Album on Imgur

His measurements are as follows

Can't tell exactly, but looks like his roll off slope follows the simulated roll off fairly closely.

 

[GM]

Interesting! They use to be one of the better mannered, well informed forums back in its early days. A pity.........

Well, if you look at it in 10 dB increments it's actually rolling off quicker, i.e. ~-20 dB/30 Hz, Vs HR's ~20 Hz, so even worse with vented only a ~5 dB 'bump' offset!

GM

 

[GM]

Load it with a Dayton UM8-22 and it's starting to get serious SPL in pairs for matching to H.E. systems even with lossy Le.

GM

 

[bigx5murf]

Load it with a Dayton UM8-22 and it's starting to get serious SPL in pairs for matching to H.E. systems even with lossy Le.

GM

That one looks great with +6db at 30Hz. Makes sense looking at the boosted plate amps they offer.

 

[phivates]

Too bad about AK. So many voices, including drunken hecklers.

 

[twocents]

The simplicity and cost of the driver makes this Bucket Sub an appealing option. Will it work just as good by putting the same driver (Peerless 830667) in a sealed 19L MDF box? Or are there better options for the price and simplicity of the build? I am looking at an affordable passive sub (to be used with full range speakers) for music in a smallish room.

 

[planet10]

i wouls suspect, except possibly for the end sitting on the floor, a cylindrical plastic (or metal) bucket should be considerably better than an MDF box.

dave

 

[GM]

What do you mean? Regarding standing waves, cylindrical shapes should be one of the better, no? Anyhow, at 100 hz the wavelenght is 3.44 meters. I highly doubt it would be an audible problem.

ewollowe: what about sonotubes? More than stiff enough and usually cheap to come by. As chris661 sait, it's just an 8" in a seal box really.

Quite the opposite in one respect; a circle theoretically has an infinite number of identical standing waves, summing to create a null at ~13543/pi/2/diameter with both even and odd harmonics.

Right, based on one of my HD buckets it's around 190 Hz.

Sonotubes, Quikrete concrete column formers, mail tubes are great for various type [ML] TLs and was very popular for DIY subs back in the '90s - early 2000s with small 'full-range' driver TLs in mailing tubes at least by the mid 60s.

GM

 

[planet10]

I was thinking about the wall resonances. In a typical sub no dimension is long enuff to have a\any standing waves of note.

dave

 

[GM]

True, though there must be enough damping to quell reflections comb filtering back through the cone and those of the vent comb filtering with the driver's output.

GM

 

[planet10]

Or the filter in front of the sub means there is nothing to excite the internal resonance.

dave

 

[GM]

True, but one can give up too much usable BW to roll them off enough, so always best IME to solve an acoustical problem with an acoustical solution as much as practical first.

GM