DIY Budget Cab! How Bad Could It Be?

[popcat]

Only skimmed through this thread, not sure if this has been covered. But, every cab will have resonance points at specific frequencies per various attributes of the cab construction vs. speaker specs. With bass cabs you can easily ruin the speaker(s) from excessive cone excursion at certain lower frequencies while only at what you may think is moderate power/volume per the speaker rating.

If you build this cab by hacking it, you should be very careful about the level you drive it with, and stay well below the rated speaker power limit at lower frequencies (<150 Hz). If the speaker goes, the amp could go with it depending on the robustness/protection of the amp design.

Both WinISD Pro and BoxNotes are free, they are a must have (at a minimum) for better understanding of the cabinet design/layout. Try looking up the make and model speaker to get a hold of the specs to input with these programs.

 

[Downunderwonder]

Egads.

What is the tuning frequency of the original Eden 410 D410XLT ?

Anyone own one? Care to measure it up? Maybe even bounce some rice on a speaker with sinewave signals to conclusively determine the tuning?

OP, what footprint can you put up with?

No rocket science here.

 

[Downunderwonder]

Eden WT550 w/D210XST Cab x 2. Loud, clean low end. Lately I've been running those cabs with the Boogie Subway 800...

borrowing your post Lava.

How's that footprint?

 

[CoffeeLove]

Here are some cabs that seem to have fairly small boxes (and footprint), that would be great to mimic, just not sure the driver could handle it. It is likely the drivers in the cabs listed below were designed to go with small boxes. I do not mind it being taller, but not a fan of a big footprint. I will pick up the free software that "popcat" suggested as well. Thoughts?

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And the list goes on. It would be great to keeep the base/foptprint fairl small, maybe around 13x15" (approx) and then build upward as needed, unless it get ridiculously tall. Maybe that is not possible, but one could hope.

Thanks againg guys, my cab will be better because you are here.

 

[fdeck]

Just a thought, which is that a new driver costs money, but not that much money, and the benefit is that it comes replete with specs that can be plugged into the speaker design software. Plus you can choose a driver whose specs are appropriate for what you want to accomplish. For my own use, the cost of a premium driver was offset by ditching all of the accessories that I don't care about such as casters, corners, jackplate, fancy port tube, carpet, tolex, custom grille, and industrial strength handles.

Another thought is to try what I call "poor mans tolerance analysis." Find a decent design that resembles what you want to achieve. Now play with the parameters, such as box volume and port tuning, and see how the graphs change. My own conclusion from this exercise is that a good design is actually fairly forgiving. We don't have to sweat over the last cubic inch of box or Hz of port. And if a driver does require some extremely specific (and extreme) parameters, then it's probably not the right driver for what you want to do.

 

[CoffeeLove]

Another thought is to try what I call "poor mans tolerance analysis." Find a decent design that resembles what you want to achieve. Now play with the parameters, such as box volume and port tuning, and see how the graphs change. My own conclusion from this exercise is that a good design is actually fairly forgiving. We don't have to sweat over the last cubic inch of box or Hz of port. And if a driver does require some extremely specific (and extreme) parameters, then it's probably not the right driver for what you want to do.

My thoughts exactly, this is meant to be an inexpensive build, and just get the job done at fairly low watts.

My question would be, what parameters can be changed once the box is built? I have those 2x4" port tubes that could be cut down as needed. I could also add another port post-build (as needed). I might shoot for 1.0 cubic feet volume, and then reduce inside volume post-build if needed ( might increase weight a little).

Thanks

 

[Rick James]

I don't care for the Eminence designs. The one you looked at is just too small. The ones that are 1.5 cubic feet per driver are better, but tuned too high. Maximum demands are made on the driver in the 50 to 60 Hz range, and if the cab is tuned to 60 hz or higher the cab runs out of both sensitivity and driver excursion capability really fast below that. You can see that in the Eminence charts.
I like that driver in 1.5 cu ft tuned to 50 Hz. The upper chart I posted here shows sensitivity, which remains strong down to 45 Hz, but the lower chart is more important, because it shows maximum SPL that takes into account both the voice coil thermal rating and the cone excursion capacity. It's much better from 50 to 60 Hz than any of the Eminence configurations.
The 1.5 cu ft size is net, you have to add the space taken up by the port and driver to that, so a gross internal volume of 1.7 cu ft would be about right. A single 4" ID port tube 6 inches long gives the best result.
But even knowing all that you're only about 1/3 of the way to a good design. The rest has to do with building techniques, bracing, damping, and a dozen other fiddly bits that a good set of plans will give you.

 

[fdeck]

My thoughts exactly, this is meant to be an inexpensive build, and just get the job done at fairly low watts.

My question would be, what parameters can be changed once the box is built? I have those 2x4" port tubes that could be cut down as needed. I could also add another port post-build (as needed). I might shoot for 1.0 cubic feet volume, and then reduce inside volume post-build if needed ( might increase weight a little).

Thanks

Aha, I should have clarified. Changing the parameters has to be done in the modeling software, though you can often give yourself the option to change the port length in your final build. In my view, a cubic foot and a 40 Hz port stand a very good chance of producing a workable cab, if the driver comes from an existing bass cab.

 

[CoffeeLove]

Look what I found, forgot I already have carpet from a cab I re-covered years ago, probably enough for two small cabs, sweet.

 

[CoffeeLove]

In my view, a cubic foot and a 40 Hz port stand a very good chance of producing a workable cab, if the driver comes from an existing bass cab.

Ya, the "1 cubic foot" will keep the size down. I am not sure how the softwre works yet, but it would be nice to plug "1 cubic foot" into the program along with my desired base dimensions, and then it give me height/tall and required port size. I know, not everything in life is that easy

 

[seamonkey]

An options
Build yourself a good FRFR cabinet. They work best with cabinet modeling software/pedals
It needs to be accurate, so that it can accurately reproduce all the other cabinets.
There are more and more cab emulation/simulation/modeling software and pedals come out every month now.
And excellent ones that are Certified and Endorsed by the original hardware manufacturer. They are that accurate.
And there's plenty of options to take your own impulse response of any favorite or famous cab and do your own.

 

[CoffeeLove]

Ok, got WinLSD up and running. Since there is know way to know original speaker parameters, I am going to use the specs from speaker listed below, it is supposedly modeled after the same speaker I have, and as others mentioned it has a similar frequency chart/graph to what they experienced with the original Eden speaker. Unfortunately, it was not listed in WinLSD so I will likely be plugging specs in manually. Off to the zoo with my kids, so will get back to this in a few hours (dang priorities).

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[BadExample]

I would like to try some winLSD, maybe listening to some early pink floyd

It's winISD

Did you get the pro version? That would be 0.7x. WinISD

 

[JimChjones]

Another interesting thing to do, if you are getting into winisd, is to input all the details for existing cabinets that you like the sound of (and perhaps some you don't as well). Everything Agedhorse says is IMHO worth paying great attention to, but the bit about every design being a compromise is crucial. So it seems to me that if you can learn a little about what compromises you like the sound of that's going to be enormously helpful. Model up that 4*10, find out what its tuning frequency was, and it seems to me that must help inform a 2*10 or 1*10 with those drivers.

I've been doing some cab building this winter with the aim of getting bulk out of the house, and I did some measurements and crude science. Amongst the things I've learned is that my Fender bass amp has a high pass filter and by the time I get to the 40hz region the *amp* is chopping loads of energy. As I really like the sound of my setup that made me figure that I shouldn't panic too much about that region. The other thing I've learned is that to my ears different length and areas of ports made far less difference to the sound and tonality than the amount of wadding on the cabinet walls inside the cabinet, so for my ears it was far more important to spend time on that than it was to worry about the ports.

Now remember the above are my lessons for *my ears*. My taste in bass sound does seem to be unusual, so sure as hell your mileage will vary.

 

[fdeck]

An options
Build yourself a good FRFR cabinet. They work best with cabinet modeling software/pedals
It needs to be accurate, so that it can accurately reproduce all the other cabinets.
There are more and more cab emulation/simulation/modeling software and pedals come out every month now.
And excellent ones that are Certified and Endorsed by the original hardware manufacturer. They are that accurate.
And there's plenty of options to take your own impulse response of any favorite or famous cab and do your own.

In my view this amounts to building a speaker that's bigger than it needs to be, and adding electronics to correct the response curve.

 

[Rick James]

Another interesting thing to do, if you are getting into winisd, is to input all the details for existing cabinets that you like the sound of .

Modeling software is only accurate up to about 200 Hz.

 

[fdeck]

Modeling software is only accurate up to about 200 Hz.

Indeed. You can get a halfway decent hybrid model by combining the software model below 200 Hz, with the manufacturer's response graphs above 200 Hz, if the latter include off-axis information.

 

[popcat]

Ok, got WinLSD up and running. Since there is know way to know original speaker parameters, I am going to use the specs from speaker listed below, it is supposedly modeled after the same speaker I have, and as others mentioned it has a similar frequency chart/graph to what they experienced with the original Eden speaker. Unfortunately, it was not listed in WinLSD so I will likely be plugging specs in manually. Off to the zoo with my kids, so will get back to this in a few hours (dang priorities).

I suggest you also get BoxNotes and bounce between the two for comparison.

 

[fdeck]

I suggest you also get BoxNotes and bounce between the two for comparison.

Hm, I hadn't seen BoxNotes before. Looks interesting. Note that the name "Box Notes" has been taken by another software app, which might be confusing if you do a search. Here's a link to the right one:

Boxnotes - Free Speaker Design Software

 

[BadExample]

And... is this the one that's supposed to be more accurate for port tuning? [compared to winisd]

Hornresp