Verically aligned speakers

[Myth_103]

Quick question regarding vertically stacked speakers. It's my understanding that it is a great idea as long as everything lines up. However, do you get the same benefits when 1 of the 2 speakers is slanted back (like the Mesa boogie vertical stacked 2x12)? It's on a different plane.. So I was wondering if there were any cons to this?

[Mr. Foxen]

Not as good as vertical, but better than horizontal basically, it is all about width of radiating plane.

[Myth_103]

That's what I was expecting. Thanks!

[billfitzmaurice]

Originally Posted by Myth_103

Quick question regarding vertically stacked speakers. It's my understanding that it is a great idea as long as everything lines up. However, do you get the same benefits when 1 of the 2 speakers is slanted back (like the Mesa boogie vertical stacked 2x12)? It's on a different plane.. So I was wondering if there were any cons to this?

Tilting the top driver back so you can hear it has some value, though it would be much better to tilt the bottom driver. That keeps the acoustical centers of the drivers closer together, which is always a good idea, whereas tilting the top driver puts them further apart. And, unless you've got ears mounted on your calves, you can't hear the highs coming off the bottom driver. But a cab like that would 'look funny', so don't count on ever seeing one from a manufacturer.

[rekesbass]

Originally Posted by billfitzmaurice

Tilting the top driver back so you can hear it has some value, though it would be much better to tilt the bottom driver. That keeps the acoustical centers of the drivers closer together, which is always a good idea, whereas tilting the top driver puts them further apart. And, unless you've got ears mounted on your calves, you can't hear the highs coming off the bottom driver. But a cab like that would 'look funny', so don't count on ever seeing one from a manufacturer.

I had a cab that had that configuration...it was a Sunn(from the 80's) with an 18" on bottom angled back and a 12" on top firing straight out...it was a beast of a cab(taller,deeper,wider and heavier than any 2x15) but, sounded pretty good..would fill any room\stage...kinda wish I still had it...although my back says NO

[jokerjkny]

Originally Posted by billfitzmaurice

Tilting the top driver back so you can hear it has some value, though it would be much better to tilt the bottom driver. That keeps the acoustical centers of the drivers closer together, which is always a good idea, whereas tilting the top driver puts them further apart. And, unless you've got ears mounted on your calves, you can't hear the highs coming off the bottom driver. But a cab like that would 'look funny', so don't count on ever seeing one from a manufacturer.

hey bfitz,

kinda curious, can you elaborate this further?

why would putting the drivers closer together be more beneficial?

[ehque]

Originally Posted by jokerjkny

hey bfitz,

kinda curious, can you elaborate this further?

why would putting the drivers closer together be more beneficial?

The closer the cone centers, the smaller the potential path difference from the cones to any point in space. The smaller the path difference, the lesser the comb filtering.

[billfitzmaurice]

Originally Posted by rekesbass

I had a cab that had that configuration...it was a Sunn(from the 80's) with an 18" on bottom angled back and a 12" on top firing straight out...it was a beast of a cab(taller,deeper,wider and heavier than any 2x15) but, sounded pretty good..would fill any room\stage...kinda wish I still had it...although my back says NO

If that cab had been properly crossed-over from the 18 to the 12 there would have been no reason to tilt the 18, as it would not have been sourcing any directional mids.

The closer the cone centers, the smaller the potential path difference from the cones to any point in space. The smaller the path difference, the lesser the comb filtering.

+1.

[JimWasHere]

Originally Posted by billfitzmaurice

If that cab had been properly crossed-over from the 18 to the 12 there would have been no reason to tilt the 18, as it would not have been sourcing any directional mids.

+1.

Making sure I understand this right... The comb filtering only occurs in the grossover region, and it's effects are limited/reduced by getting the acoustic centers closer? This is why we use really steep crossovers in 4 way foh systems, and vertically align stuff resulting in a line array at higher frequencies? Which was my understanding before, I'm just trying to make sure I understand it correctly.

[GBassNorth]

I remember seeing a Bassman 412 cab that had the speakers in a diamond layout, all 4 speakers tilted towards a center point (top tilted down, bottom tilted up, left tilted right and right tilted left). Never got a chance to hear it so no comment there.

[pfschim]

Originally Posted by GBassNorth

I remember seeing a Bassman 412 cab that had the speakers in a diamond layout, all 4 speakers tilted towards a center point (top tilted down, bottom tilted up, left tilted right and right tilted left). Never got a chance to hear it so no comment there.

don't have the acoustic science cred to comment on the quality of this Fender "tilted" 4x12 cab design, but I can say from personal experience with one that it did not sound or work very well.

[Mr. Foxen]

Originally Posted by GBassNorth

I remember seeing a Bassman 412 cab that had the speakers in a diamond layout, all 4 speakers tilted towards a center point (top tilted down, bottom tilted up, left tilted right and right tilted left). Never got a chance to hear it so no comment there.

The speakers were all miles apart and the box was massive but still with no air inside, so it was all a bit fail. The worst part of the bad sound was the fact the box was made badly though, split seams and stuff that made serious bad noise rather than some compromised dispersion. Trace Elliot made a much more compact three speaker one (the top one pointing down was major fail with the fender, the up an outward ones are kind of good), one up, two facing to the sides, inward as it were, good idea, crap sales from looking weird, and impedance being odd.

[Downunderwonder]

Originally Posted by JimWasHere

Making sure I understand this right... The comb filtering only occurs in the grossover region, and it's effects are limited/reduced by getting the acoustic centers closer? This is why we use really steep crossovers in 4 way foh systems, and vertically align stuff resulting in a line array at higher frequencies? Which was my understanding before, I'm just trying to make sure I understand it correctly.

You've extrapolated incorrectly.
Comb filtering occurs at all frequencies, directional and subwoofer. Crossovers are designed to minimise phasing I believe, gets way over my head but someone will fill you in on a lazy Sunday.

[lo-freq]

Originally Posted by billfitzmaurice

...

But a cab like that would 'look funny', so don't count on ever seeing one from a manufacturer.

6x10 instead of 2x12, but there it was (now discontinued):

Thunderfunk 610

12x5:

http://www.philjonespuresound.com/pr...photos/210.jpg

[RobJ]

Originally Posted by rekesbass

I had a cab that had that configuration...it was a Sunn(from the 80's) with an 18" on bottom angled back and a 12" on top firing straight out...it was a beast of a cab(taller,deeper,wider and heavier than any 2x15) but, sounded pretty good..would fill any room\stage...kinda wish I still had it...although my back says NO

I have one in storage, I believe the model number is 8028. I agree it does sound pretty good but is really a beast to move around; I seem to recall it weighs in at 148 lbs. Thankfully mine has the pop out casters which helped a lot back when I was using it.

[billfitzmaurice]

Originally Posted by Downunderwonder

Comb filtering occurs at all frequencies, directional and subwoofer.

It only occurs when multiple sources are more than 1 wavelength apart center to center.

Originally Posted by billfitzmaurice:
If that cab had been properly crossed-over from the 18 to the 12 there would have been no reason to tilt the 18, as it would not have been sourcing any directional mids.

Making sure I understand this right... The comb filtering only occurs in the grossover region, and it's effects are limited/reduced by getting the acoustic centers closer? This is why we use really steep crossovers in 4 way foh systems, and vertically align stuff resulting in a line array at higher frequencies? Which was my understanding before, I'm just trying to make sure I understand it correctly.

See above. That is one of the functions of a crossover, but you also don't get combing if you don't cross over at a high enough frequency where their acoustic centers can be more than a wavelength apart, so prevention of combing is accomplished both electrically and physically.

there it was (now discontinued):

TalkBass Forums: The Bass Guitar and Double Bass Online Community

12x5:

Page or File Not Found | Phil Jones Pure Sound

Those have the upper drivers aimed upward. The better method is to have the lower drivers aimed upward.

[lo-freq]

Originally Posted by billfitzmaurice

...
Those have the upper drivers aimed upward. The better method is to have the lower drivers aimed upward.

Not familiar with that cab; I thought that was what he was talking about (like the Marshall 4x12 where the top two are slanted upward a bit).

...My bad!

[JimWasHere]

Originally Posted by billfitzmaurice

It only occurs when multiple sources are more than 1 wavelength apart center to center.

See above. That is one of the functions of a crossover, but you also don't get combing if you don't cross over at a high enough frequency where their acoustic centers can be more than a wavelength apart, so prevention of combing is accomplished both electrically and physically.
Those have the upper drivers aimed upward. The better method is to have the lower drivers aimed upward.

This connects about 6 things that I've all recently learned.. Thanks

[MIJ-VI]

Originally Posted by billfitzmaurice

Tilting the top driver back so you can hear it has some value, though it would be much better to tilt the bottom driver. That keeps the acoustical centers of the drivers closer together, which is always a good idea, whereas tilting the top driver puts them further apart. And, unless you've got ears mounted on your calves, you can't hear the highs coming off the bottom driver. But a cab like that would 'look funny', so don't count on ever seeing one from a manufacturer.

[billfitzmaurice]

Originally Posted by MIJ-VI

As already noted that infamous Fender was one of the worst bass cabs ever created. In addition to exceedingly poor construction the cab interior volume was too small for a decent low end, it was loaded with guitar drivers, and exactly who was that tilted down top driver supposed to be aimed at? But otherwise it was a dandy.

This is what the side view of a cab with the lower driver tilted back would look like: