Please poke some holes in this concept before I waste time

basscooker

basscooker

Commercial User
Apr 11, 2010
5,610
9,648
5,461
Northern KY
Disclosures
Cab fan, hobbyist
#1
Looking for knowledgeable designers input on a thought I had the other day.

I imagined an 8x8 (or 8x10) three way cab. A pair of good robust subs in a ported enclosure, a bandpass 410, and a pair of mids. Three chambers, two port tuned.

I'm figuring the sub chamber and 410 chamber tuned an octave apart, maybe 30 and 60 respectively. Using something like 70/3k as the filter points. (these numbers are just thrown out there). The 410 basically running full range, but high passed at about 70, low passed at around 3k, with a sub and mid drivers taking care of some content on either side of those two points.

Okay, learning hat on. Poke some holes in my concept before I dive into searching drivers and modeling.


A couple things I already know: Big and heavy. Could easily be a mud-maker in high volume situations, and the "sub" is overkill and unnecessary when FOH is present. It could be a power-suck, with low sensitivity subs eating up the majority of the amp's power.

Responses to those: Wheels. Made for use when no FOH is present, two L-pads. Possibly a way to bypass the sub chamber, or give it an independent input. Details, details. First I need to hear if it's a case of physics not caring that my logic says it might work, lol.
 
#3
And there.

Thank you. If I can't come up with the reasons NOT to do something it drives me crazy. When (in this particular case) two days digging through threads, website after website and the cookbook I couldn't find the exact answer, I knew you'd come to the rescue. My sanity thanks you.

/ thread. ;)
 
  • Like
Reactions: agedhorse
#5
What you are proposing reminds me of a Magnatone cabinet that Neil Young uses. They were built for trade shows, and music stores, not for retail sale.


IMG_1403.JPG
 
  • Like
Reactions: spankdaplank, deathness and Sartori
#7
Right. Well maybe I described it wrong. Two 8"subs. Four full range 8". Two 8" mids. Tune accordingly, find good filter points. So beyond those processes of tuning it and finding good frequencies to cross them over, phasing is something that can't be accounted for? I trust you're right, don't do it, but please elaborate. I'm having trouble with understanding how it would be different than three different cabs designed to work together as a 3 way system, but in a single box, tuned for an electric bass. It would require a two channel amp, I guess. Remember though, this thing never even made it to paper yet. Just a bunch of googlying and reading. On a phone. I need glasses now.
 
#8
The phase response of the "bandpass full range" (bandpass type boxes are anything but full range) will almost certainly very different than the other boxes, making a poor choice to combine with other boxes.

This is a more complicated subject than you realize.
 
  • Like
Reactions: tryinalearnDan
#9
basscooker said:
Well maybe I described it wrong. Two 8"subs. Four full range 8". Two 8" mids.
Click to expand...
That arrangement ignores at least three basic rules of speaker design. First, the lower the frequency the more driver displacement you need. If you must use eight 8" then four of them should be subs, two midbasses, two midrange. Even better, six subs and two midrange, since 8" subs go high enough that they don't need midbasses. Second, the higher the frequency the smaller the cone size needs to be for dispersion. So instead of 8" midranges 6.5" would work better, and they must be vertically arrayed, or the dispersion will be halved. Third, you never have different drivers working in the same frequencies. Bag the full range drivers entirely, they've got no reason to be there. Last, why 8" subs? Instead of four 8" subs one 15" would would at least as well, probably better, and cost a lot less.
 
  • Like
Reactions: Jules Meuffels
#11
Purely an exercise in the journey to more complex bass cab designs. I greatly respect, all the knowledge and experience you guys bring to the table. My own doubts came into play immediately, but i couldn't find the right "no" in the mountains of pages i tore through. Thank you all again. Baby steps.
 
#12
agedhorse said:
The phase response of the "bandpass full range" (bandpass type boxes are anything but full range) will almost certainly very different than the other boxes, making a poor choice to combine with other boxes.

This is a more complicated subject than you realize.
Click to expand...
Without being argumentative or asking you to give away trade secrets Andy, from a purely conceptual point of view how would this be tremendously different from two cabs on a stage, one being a sub-woofer and the other a high passed full range complementary cab? If it has to do with the drivers all being in the same cab and/or in close proximity and how the sound waves would propagate/interfere (phasing, combing, cabinet resonance, whatever,...) that would make sense to me.

Thee are some rather full spectrum cabs out there that can already do almost sub lows to fairly high (relative to our ability to hear) frequencies, and they're in a single box. I can see it being a challenging problem - so are you saying that it is a lot more complex than would be worth the end result, or it's not likely that it could ever be pulled off with great results. Just curious to understand the science here a little better. Thanks! :)
 
  • Like
Reactions: basscooker
#14
Peavey had a PA speaker system (3020HT) with the same sort of idea. Two massive cabs and a head. It sounded great, but it was an absolute nightmare to move around... I know. We rented the system for a gig—and the club was in the basement. Never again.

But if you own a club and will never have to move it (or have roadies that you don't care about) go for it!

00281383142059903.jpg
 
#17
If you have money and time to burn and don't mind ending up with a white elephant that you either don't like or isn't quite what you expected (and would be difficult to sell in that case) ... sure, go for it. However, there are so many great options out there that you can actually try out to see if they work for you before taking the plunge. Keep it simple, get an Ampeg SVT and matching 8x10 and be done with it. ;^)
 
#18
2x8" or 2x10" wont give you the lows you're looking for (check the specs).
The thing will be huge and heavy.
2x8" will bundle the highs.
It'll take you more than a year to design and build this thing, if you're looking for perfection and don't have all day, everyday.
In the end very expensive... drivers, woodworking, filters, hardware, etc.
;)
 
#19
Al Kraft said:
Without being argumentative or asking you to give away trade secrets Andy, from a purely conceptual point of view how would this be tremendously different from two cabs on a stage, one being a sub-woofer and the other a high passed full range complementary cab? If it has to do with the drivers all being in the same cab and/or in close proximity and how the sound waves would propagate/interfere (phasing, combing, cabinet resonance, whatever,...) that would make sense to me.

Thee are some rather full spectrum cabs out there that can already do almost sub lows to fairly high (relative to our ability to hear) frequencies, and they're in a single box. I can see it being a challenging problem - so are you saying that it is a lot more complex than would be worth the end result, or it's not likely that it could ever be pulled off with great results. Just curious to understand the science here a little better. Thanks! :)
Click to expand...

A full range band-pass style speaker is anything but full range, nor does it have predictable response suitable for bass guitar. Besides, the phase response combined with the sub cabinet (there will be some significant overlap at the low end if the bandpass "full range" box is run full range) will result in significant phase interactions (peaks plus dips).

There is a reason why you don't see many attempts at band pass boxes intended for high quality bass guitar.
 
  • Like
Reactions: Al Kraft
You must log in or register to reply here.
Top Bottom
Back