Cab Build Questions...

hennessybass · #1 06-28-2010, 03:21 PM

Hey guys, I am trying to find a new cab, and I'm getting close. I can feel it!! I have found some stuff I like, but I am considering a custom build - LDS maybe? Anyway, I have a few ideas and want to run them by everyone and see what kind of feedback I get...

My set up is a 64 NOS Jazz or a 69 tele bass. Straight into my amp - currently using a Fender Bassman 100, but might upgrade to a 200watt tube amp. No effects, nothing fancy. I like "old school tone." No tweeters! Looking for something tight and focused - don't want my low end getting away from me.

So I really like the Berg NV412 and that's probably what I'll go with, if I don't do a custom job...

Can I just have someone build the same box as the NV412 and put Neo speakers in it. The NV412 is a sealed cab, so there shouldn't really be a problem with "Tuning" the cab for the specific speakers, right?

The cab is 3'tall, 2'wide, 15"deep, sealed. I get the whole "dropping speakers in a box" thing, but does that matter with a sealed cab? I'm not doing anything crazy - the box size is proven --The NV412 and the NV610 are the exact same box - different speakers. So it's not exactly like Mr. Bergantino specifficly engeniered either one of those cabs specificly for their respective speakers, right? It's just a good box size for say 610s or 412s.

Any concerns with doing this? Is there something that would make my custom cab sound bad? Any thoughts??

The only other design thing I might change is NO tilt back casters - I'm over 6 ft and don't want to be hunched over rolling this beast around. I had an Ampeg 410HLF and hated the tilt back thing. I think 4 swivel casters is easiest to move. So, I would put removable swivel casters on the side -- roll it in, flip it up, and remove casters for playing. With this, I would probably put two handles on the opposite side (top when it's being moved / side when played) of the casters so that the cab is transported and moved as a horizontal cab, but then played as a vertical cab. When rolling the thing around in the horizontal position, it would only be 1foot wider than an average 410.

Petebass · #2 06-28-2010, 03:50 PM

Quote:

Originally Posted by hennessybass

the box size is proven --The NV412 and the NV610 are the exact same box - different speakers. So it's not exactly like Mr. Bergantino specifficly engeniered either one of those cabs specificly for their respective speakers, right? It's just a good box size for say 610s or 412s.

Wrong!

When you're talking sealed cabs, the cab size is certainly less crucial than for ported cabs, but it's still important.

The more critical factor is picking drivers which are suited to a sealed cab. You're looking for high X-max, high QTS, and an appropriate EBP.... usually <50 but this isn't a hard and fast rule so there's also a fair bit of modelling and even some trial & error required.

There's more to it than first meets the eye.

chiplexic · #3 06-29-2010, 07:32 AM

As great as Bergantino cabs are I have found it interesting that, that same cab has been used for the 610,the 412 and I think the 215 NV cabs.
No doubt he knows what he's doing! I have done some DIY builds and mock ups of different ideas (not necessarily successfully). If anything I actually find it encouraging that 1 cab was able to be used for so many uses.
The one side note to that is, Jim B. obviously has his drivers custom spec'ed. So that adds a whole different angle on why that one sized cab has been so versatile.

Try looking at Eminences, select a speaker, and look at the file for different cab ideas. They usually have at least one for a sealed cab for each driver. Kind of interesting to see what size they choose for that sealed cab. Also down load for free WinISD software for cab design. You can mock up many scenarios for you ideas with many drivers. And you can add a driver if it isn't already on their drop menu.

billfitzmaurice · #4 06-29-2010, 07:37 AM

Quote:

Originally Posted by hennessybass

I get the whole "dropping speakers in a box" thing, but does that matter with a sealed cab? .

It does. The drivers and cab must be properly matched for a good result in the low end, and as is always the case with a one-way system horizontal midrange dispersion will suffer if the drivers are not vertically aligned.

chiplexic · #5 06-29-2010, 07:43 AM

Quote:

Originally Posted by billfitzmaurice

and as is always the case with a one-way system horizontal midrange dispersion will suffer if the drivers are not vertically aligned.

Is this more effective when the speakers are in a single row as opposed to say two verticle rows side by side? Like an Ampeg 810 would be?

billfitzmaurice · #6 06-29-2010, 07:50 AM

Quote:

Originally Posted by chiplexic

Is this more effective when the speakers are in a single row as opposed to say two verticle rows side by side? Like an Ampeg 810 would be?

Yes. Dispersion on the horizontal is inversely proportional to the width of the source. Side by side rows of tens will have horizontal dispersion about the same as a twenty-one.

That's why users of vertical 2x15s find that their mids are just as good as, if not better than, 610/810s.

will33 · #7 06-29-2010, 05:22 PM

Quote:

Originally Posted by hennessybass

Can I just have someone build the same box as the NV412 and put Neo speakers in it. The NV412 is a sealed cab, so there shouldn't really be a problem with "Tuning" the cab for the specific speakers, right?

.

You could but it wouldn't sound like the Berg. For one, they are proprietary drivers, meaning although they may have started with a common design frame, different aspects of the speakers have been tweaked to get a sound that particular engineer wanted. Using an off the shelf speaker, may sound good, but not the same.

Also most commonly available speakers are design for use in ported cabinets. There are a few that are not but they are few. Speakers designed to perform their best in sealed cabs have parameters/designs different than typical vented box speakers. There are some that can do ok in either but whether going vented or ported, you'd be getting what, 85% at best of what you could be getting.

Bill's point about horizontal dispersion is one overlooked by most builders. Most common bass cabs still have a hotspot when centered on them like a guitar 212 or 412 does. Move off to one side and you lose a lot of mids and highs.

muddycreek · #8 06-29-2010, 06:23 PM

If you're considering LDS, it sounds like you need to have a good dialogue with Don and tell him your design goals and ideas, and let him help you reach them. That'd be why you were paying him in the first place.

A few inches here or there away from the Berg dimensions could be all the difference for the specific drivers you and Don pick out to reach your goals.