Silly bass cab idea?

[Ayek]

So I got a Hartke Transporter 1x15 bass cab with a Black Widow inside. It sounds pretty good. Problem is the shitty cab construction vibrates like all fuck and it walks around and ruins any amp that dares to sit on it. I ain't got much bread to spend on a new unloaded cabinet and I am restricted by my geological location and I don't have the space and tools to build one properly. So I was thinking of getting some 1" square or so wood to brace the corners internally and using some plywood I got to add an additional layer to it, as it's only about a 1/2" thick. Bad idea? I don't think it could make it any worse.

[Corey Y]

No need to add extra plywood, the bracing would do the trick fine. Although 1" square might be excessive. Some insulation would probably be a good idea as well. All you're trying to do is prevent excess vibration, so it's just a matter of increasing rigidity and dampening.

[Mr. Foxen]

Cross bracing is the best way, sticks from one side to the other. Adding thickness is the heaviest way to achieve the least in terms of stiffness, cross bracing is light and does the most.



Also line it with knobbly foam.

[Ayek]

Sounds like a plan, then. Though I was thinking of just bracing in along the inside of the corners as I won't be able to get anything longer than the 15" that the speaker hole allows. Kinda like what's done here:

Except I only got the speaker hole to work with unless I bust the thing apart, which I want to avoid.

[Mr. Foxen]

Corners that are stuck together are already the stiffest points on account of being corners. If they aren't stuck together, then its already busting apart. The middle bit of the panel flexes which is what you need to stiffen.

Edit: someone posted pics of doing it on another forum: http://basschat.co.uk/topic/179802-i-finally-got-around-to-dampening-bracing-my-laney-cab/

[Ayek]

Right-o then, looks like a winning ticket.

[mortlock]

does the physics jive??

[Ayek]

Are you referring to the cab dimensions in relation to the speaker? The cabinet I have is very similar in dimension to a peavey with the same speaker.

[jibberish]

anyone ever play with H-PAS or other type of bass enhancing speaker designs for music?   you can make 6" woofers thunder in the right enclosure. obviously the 6" can only move so much air so it has volume limts to be sure. i suppose several drivers could be used.   i could only imagine what a couple 10" in a larger enclosure would do.

i also always contemplated a road/stage bass enclosure that was transported in like 2 nested halves that you took apart and re-attached for a 2x volume cabinet for performance.

[Mr. Foxen]

Vast majority of bass cabs are tuned resonators, the H-PAS is one alignment, nothing special there except marketting BS, the fact the arrows go in one direction on the video pretty much shows that. Picking a speaker for low end is about looking at the Xmax spec, that is how far it goes back and forth and is the major determining factor in how much volume displacement it has and thus its maximum low end SPL. Then you tune and enclosure to it to be suitable for the sort of sound you are after, either flat as low as it can (max flat amplitude response) or with a bass hump where you want it (usually where your ear is sensitive, like car subs).

[jibberish]

the reason i mention this, is that i rebuilt a pair of phillips speakers. they had 2 6" woofers and a std phillips ferrofluid tweeter. i totally melted these speakers down heh.

SO, i rebuilt them with kicker long throw 6" woofers(100w CONTINUOUS powr handling each) and a new phillips style tweeter.

these are god's speakers now. unbelievable how rich, deep and powerful the bass is, and these werent any fancy cabs, just a small vent in back. THEN i got to thinking about what would these drivers be like in an enhanced bass cab like an H-PAS or transmission line column or w/e. if i paid attention to the mid's better, those would be stellar home speakers. super musical, just a bit thin in upper mids, but they are the best low volume speakers ever since they have the extra full bottom end.

my DCM time windows coincidentally are a pair of 6" woofs and a pair of phillips style ferrofluid tweeters in a TLC.  they are world class fidelity. Why? 6" woofers move really fast and dont smear out upper bass/low mids due to inertial delay distortion and secondary cone flexing. the TLC enhances the deep bottom end and they are flat to 30hz (no they dont thunder. would need subs to add the thunder). nothing images like time windows and super snappy drivers are a big part of that too.

and in conclusion: fancy bass enhancing enclosure designs are not just marketing bs. they really can set up a system nicely....so maybe someone can get same amount of bass from 1/2 the amount of drivers if they are clever with the cabinetry

[Mr. Foxen]

H-PAS according to the diagram is just a standard ported enclosure with added marketing BS. Transmission line have a massive phase difference between the line output and the cone output, although those don't actually matter, much like the 'inertial delay' doesn't. There is no such thing as a free lunch with cabinet tuning, transmission line need to be huge and stuffed just right to work properly, horns limit your passband and are also huge. Heimholtz resonators like standard ported enclosures are the most practical since they are easy enough to model to be able to match them to drivers in software. Cone flexing is a cone breakup mode, and those are often beneficial for musical purposes as it can improve dispersion and add punch to the mids as it tends to be a bit of distortion in the midband that is useful musically.

[moose23]

Helmholtz

[jibberish]

H-PAS according to the diagram is just a standard ported enclosure with added marketing BS. Transmission line have a massive phase difference between the line output and the cone output, although those don't actually matter, much like the 'inertial delay' doesn't. There is no such thing as a free lunch with cabinet tuning, transmission line need to be huge and stuffed just right to work properly, horns limit your passband and are also huge. Heimholtz resonators like standard ported enclosures are the most practical since they are easy enough to model to be able to match them to drivers in software. Cone flexing is a cone breakup mode, and those are often beneficial for musical purposes as it can improve dispersion and add punch to the mids as it tends to be a bit of distortion in the midband that is useful musically.

ok. i know we have contrasted stereo vs music reproduction before, especially the musical distortion vs reproduction clarity.  i have never played with H=PAS.  but reading, it seemed pretty cool.
so tuned ports it is...
From looking at every music setup pretty much ever, i kind of figured it always works out to number of drivers for music since that is what everyone does, except maybe bose. but always have to toss out the things im wondering about.

  back in the stereo world, Klipschhorns, one of Klipsch's first designs was a big mambo cabinet that fit in a corner and actually used the wall as part of the bass horn structure to get that last bit of really low end that you need a huge horn for.   and as you noted, TLC's have to be loaded correctly.  hence the preference of 6" woofers so the cabinets can stay a reasonably small size. there was a small EPI tower that i believe maybe even had a 4" long throw. the thing was maybe 30" tall. amazing sound for a tiny ass speaker. after seeing that in operation, i always sort of checked out any other TLC style cabinets.

[Ayek]

I done the cross bracing thing on my cab a while back and stuck some wood in the corners on account of the cabinet being even more of a poorly constructed piece of shit than I first realised. Glued and screwed it all up. Seems to do the trick, first test was sitting the amp on atop of it with an opened beer on top of the amp then turning up. Shook the floor, but not the beer. I haven't lined the inside of the cab on account of not having the stuff when I had it open. Here's pictures.

[Mr. Foxen]

Good work. Mattress topper stuff from Walmart is apparently good for lining, but don't have it in Asda-Walmart over here, I just use knobbly foam from packing. The bracing sorts the low end, the lining will give a bit more clarity in the mids/treble.

[Ayek]

I know a dude who build A/C ducting and I could prolly hit him up for some of the insulating they use