Vertical cab stacking---the only way to play

[Melvin7822]

reflections have always less power than direct sound... now figure how comb filtering works with two sources with the same power!
your book are talking about one source, I guess.. the same applies to more sources, but they are at the same acoustic power.

I think when we get into sources with the same power, we get into frequency summation or "beaming" if you will. I guess it all comes down to what you believe comb filtering includes.

However, the one thing I do agree with is that vertical stacking should affect dispersion, because the summation is on the vertical plane.

 

[ZolkoW]

However, the one thing I do agree with is that vertical stacking should affect dispersion, because the summation is on the vertical plane.

yes, I think it's been mentioned already here, or in the other topic, that simply going to vertical doesnt eliminate CF, just helps dispersion horizontally. (If I understood correctly)


anyway: last saturday I played on a 15+4x10 stack, and one noticeable effect was, that if I didn't stand right in front of it, I couldn't hear myself very well. two steps sidewise, and half the volume.. I don't know, if it's because CF or what, but it was noticeable with this current rig.

 

[Melvin7822]

yes, I think it's been mentioned already here, or in the other topic, that simply going to vertical doesnt eliminate CF, just helps dispersion horizontally. (If I understood correctly)


anyway: last saturday I played on a 15+4x10 stack, and one noticeable effect was, that if I didn't stand right in front of it, I couldn't hear myself very well. two steps sidewise, and half the volume.. I don't know, if it's because CF or what, but it was noticeable with this current rig.

I would argue that what you're hearing is summation where the frequencies are converging in the center and appear less off axis because of this. I think the object of this whole post is to actually point out that a point source is best for dispersion.

 

[ZolkoW]

I would argue that what you're hearing is summation where the frequencies are converging in the center and appear less off axis because of this.

I1m not sure if I understand correctly... is this summation something different than CF?

a point source is best for dispersion.

Sure, but mostly one driver is not enough..

 

[billfitzmaurice]

I would argue that what you're hearing is summation where the frequencies are converging in the center and appear less off axis because of this. I think the object of this whole post is to actually point out that a point source is best for dispersion.

The point is that a line source is best for dispersion. A 4x10 is not a line source and suffers a narrow dispersion angle as a result. I know it's a long thread, but you should read it from the beginning.

 

[Melvin7822]

Sorry Bill,
I did read it from the beginning, but as you say it is a long thread and a lot to remember. What you are saying does make sense and I mixed up the points. Sorry, ZolkoW.

+1 on the line source being the best for dispersion.

 

[Rick Auricchio]

Bill, I presume you meant:

A [square-box] 4x10 is not a line source and suffers a narrow dispersion angle as a result.

 

[Stumbo]

anyway: last saturday I played on a 15+4x10 stack, and one noticeable effect was, that if I didn't stand right in front of it, I couldn't hear myself very well. two steps sidewise, and half the volume.. I don't know, if it's because CF or what, but it was noticeable with this current rig.

Isn't this similar to standing in front of a (for example) 4x10 and the bass player keeps turning up to hear him/herself but FOH, the volume is so deafening that it ruins the mix.

Stand to the side of your cabs, it seems to me, will do the same thing. Isn't that why certain cabs have speakers on the sides or on the bottom? To increase dispersion?

As has been posted many times before, IME, you have to go out FOH about 50 feet to hear how you actually sound in the mix. IMO, If it sounds good to you, that's as far as you have to go as far as analyzing your sound. Otherwise, you can experiment until it does.

 

[Rick Auricchio]

I've never seen a cab with drivers on the side. As for the bottom, it could be for efficiency.

Having good house sound is what we're after when avoiding the "power alley" cancellation issues. But dispersion of the mids is what generally makes the bass intelligible in the mix. Bad dispersion means we can't hear ourselves onstage either.

High stage volume often wreaks havoc with PA support. Poor stage audibility makes people turn up, and the FOH engineer loses every time.

 

[billfitzmaurice]

Bill, I presume you meant:

Not counting all the vertically aligned 4x10s on the market, of course.

 

[ZolkoW]

After finishing my second 1x12, I think I'll go for a vertical 3x10. it's OnTopic :-D, closer to my ears, easier to put in the car (easier than an equivalent volume cube), has stiffer walls than a cube (needs less bracing), looks unique, BUT I can't stack my head on it
I must stand it on the floor... I hope the sound will satisfy.. If not, I can still put the drivers into a cubic box ;-)

 

[billfitzmaurice]

BUT I can't stack my head on it
I must stand it on the floor...

That is the number one reason why bass and guitar cabs are made with the dimensions that they are, going all the way back to the first combo amps of the 1930's.

 

[Stumbo]

That is the number one reason why bass and guitar cabs are made with the dimensions that they are, going all the way back to the first combo amps of the 1930's.

So is it that the cabs that sounded pretty good back in the day plus held the head on top were built on guesstimates?

If, say the Sunn 2000s cab, was reverse engineered using today's software, how far from ideal would it be?

I wonder what Mr. Sundholm would have to say on this?

Just curious....

 

[John D Harris]

After finishing my second 1x12, I think I'll go for a vertical 3x10. it's OnTopic :-D, closer to my ears, easier to put in the car (easier than an equivalent volume cube), has stiffer walls than a cube (needs less bracing), looks unique, BUT I can't stack my head on it
I must stand it on the floor... I hope the sound will satisfy.. If not, I can still put the drivers into a cubic box ;-)

I use a thin foam rubber pad between my CX-310 and my rack case and then use bungie cords to make sure the case doesn't go anywhere.

 

[billfitzmaurice]

So is it that the cabs that sounded pretty good back in the day plus held the head on top were built on guesstimates?

If, say the Sunn 2000s cab, was reverse engineered using today's software, how far from ideal would it be?

I wonder what Mr. Sundholm would have to say on this?

Just curious....

The original Sunn 200S was designed entirely through guesswork. Not only that, Sundholm called it a folded horn. It wasn't. He'd heard of the term, didn't know what it actually meant, and applied it to his cab, which was actually a bass reflex with a reverse flared duct. It did work better than most cabs of its day, but that's because it used premium drivers in a ported cab, as opposed to the cheaper Jensens etc. in sealed cabs that were the norm of the day.
There was nothing intrinsically wrong with design via trial and error, more properly known as Empirical Design. Prior to Theile/Small it was pretty much the standard design method. The advantage to using T/S isn't that it will give a better result, it's that you can accurately predict the result, removing guesswork from the process.

 

[ZolkoW]

I use a thin foam rubber pad between my CX-310 and my rack case and then use bungie cords to make sure the case doesn't go anywhere.

thanks.. yes, the CX310 isn't much narrower than a rackmount head

OFF:
by the way.. is the 310 really a horn design?
is it possible/does it make sense to build a horn into such a small (or into my 1x12 ) box? what I understand from horns is that they help achieve better efficiency... but for a lof freq coupling they have to be large (1/4 wavelenght minimum?).. don't they?

 

[Stumbo]

The advantage to using T/S isn't that it will give a better result, it's that you can accurately predict the result, removing guesswork from the process.

Thank for the info.

 

[John D Harris]

thanks.. yes, the CX310 isn't much narrower than a rackmount head

OFF:
by the way.. is the 310 really a horn design?
is it possible/does it make sense to build a horn into such a small (or into my 1x12 ) box? what I understand from horns is that they help achieve better efficiency... but for a lof freq coupling they have to be large (1/4 wavelenght minimum?).. don't they?

Most of EA's cabs are supposed to be 'transmission line' enclosures.
Comments from one of our talkbass cab design guru (forget which one) indicate that it indeed could not have a long enough rear wave path to qualify -- more like a cross between a TL and a regular ported design.
I think it is more about linear response of the low end and eliminating rear waves bouncing back through the cone (the insides of the cab behind the drivers are stuffed with foam) than efficiency.

It does have a tighter low end than any of my previous cabs (Bergantino HT322 & Schroeder 410R).

 

[jeffgnr90]

I have an Acoustic b115neo and an Acoustic b410. how would I set that up to est optimize it's performance. Regardless, I'm planning on selling both these cabs for something else, preferable 2 210's or 2 215s. what should I get to best push my 600w 2ohm head? I know ohms plays a factor but I just don't know what to do speaker-wise. I play in a 3 piece "prog" rock band and use lots of OD/distortion. Im kind of going for that Geddy Lee type sound like from Moving pics which I have down prettty good, atleast to my ears.

 

[Floyd Eye]

That's great Jimmy and I am happy that you are so happy. I think I'm going to stick with the 810 for a bit longer though. No offense.