How do cabs even work?

[mayoayox]

whats the baffling do? how does that all affect the tone? i can read schematics but i still dont really understand physical sound design after the signal leaves the amp

Prompted by a five watt world video on the Ampeg B15

I can watch videos comparing 4x10 vs 1x15 or closed vs open back, but I still have a hard time with some vocabulary words like Baffling, and how that affects anything. I've also seen intricate double box designs from people building for their cars sound system -- how does sound travel through a box like that?

I might have a hard time understanding in text, but ive tried Google and YouTube and searching this forum. ANY help is appreciated, but a YouTube video is doubly so.

 

[Hoochie Coochie Man]

I don't know why, but your post reminded me of a quote I first heard at least five decades ago:
Eros spelled backwards is Sore.

If you search TB for posts I made about Eros, you may find where I posted about Eros amplifiers. When we hauled some of the really big Eros amps and cabinets around (especially one of the four-fifteen cabs) back in the 1970s, I made the same observation you did.

 

[Hoochie Coochie Man]

Jazz dog.
My post about Eros

View attachment 1146282 View attachment 1146275

I used to frequent a music store back in the 1970s whos owner was an electrical engineer, (and violinist), who built a factory to manufacture his own line of PA, guitar, bass amplifiers, and speaker cabinets. The company was called Custom Electronics & Engineering, and used the brand name Eros.
I mentioned to the owner of a music store in the same town that if he ever came across any Eros amps, that I would be interested in buying one. A week later, they told me that they had just acquired some Eros speaker cabinets. I purchased two 115 bass cabinets that had never been sold by the original company, and had been stored in a barn since the mid 1970s. Some time later, I was able to buy an amplifier that was assembled recently using new-old stock parts from the original defunct company that had been stored in the barn, combined with a newly constructed reproduction enclosure. These amps used a couple different Dynaco power amps combined with a preamp section of their own design. This one was called The Bass Master and used a Dynaco MK II power section. The speaker cabinets were insanely heavy. They were constructed of high density particle board. I remember helping a guitar player haul one of these that had FOUR 15 inch speakers in it up a flight of stairs. I was a strong young man back then, and it still was a lot for two of us to handle. I bought this rig purely for the personal nostalgic value it holds for me to remember the old days. It is a very cool amp. We think the speakers are Eminence. They have aluminum dust caps, with a screened hole in the center.

 

[Wyvern]

Factually, one of this is consistent with my 40 years of professional speaker design. This sounds like you got some (inaccurate) AI assistance with these statements of "fact".

The only thing indisputable is your preference for what you like personally.

No Ai, no facts, just my experience which is minimal for guitar and bass cabs- so I'm not stating anything as fact. I've only had like 4 cabs, and demoed a couple more.

I hate AI with a passion, I won't give it one drop of water!

I know a little bit more with home audio, I have an okish 7.1.2 Atmos home audio system- Polk signatures were dead cheap during COVID. I used to ressurect dead sprakers growing up


But please correct what I said, I am curious to learn more.

 

[agedhorse]

No Ai, no facts, just my experience which is minimal for guitar and bass cabs- so I'm not stating anything as fact. I've only had like 4 cabs, and demoed a couple more.

I hate AI with a passion, I won't give it one drop of water!

I know a little bit more with home audio, I have an okish 7.1.2 Atmos home audio system- Polk signatures were dead cheap during COVID. I used to ressurect dead sprakers growing up


But please correct what I said, I am curious to learn more.

From your text below:

Open bottom port cabs sound open, sealed cabs sound compressed, single port cabs sound like closed cabs with more sub-bass response.

Makes no sense as that’s not how it works. Maybe it applies to a single cabinet that you happened to listen to, but that’s not because of bottom port versus single port or sealed topology.

Small cabs sound more middy, oversized cabs tend to have less bass and more openess.

Cabinets sound like they do because of the drivers used, the skill of the designer and their intent. If anything sad a generalization, larger cabinets tend to have greater low frequency extension. Openness has nothing to do with cabinet size.

10's sound flat (even) 12's have a "V" shape usually (enhanced lows and highs) 15” have more high mids and woofy lows.

None of this is accurate, it’s driver and designer influenced and I can give more examples of speakers that are the polar opposite of that you describe than speakers that fit your description.

 

[Wyvern]

From your text below:



Makes no sense as that’s not how it works. Maybe it applies to a single cabinet that you happened to listen to, but that’s not because of bottom port versus single port or sealed topology.



Cabinets sound like they do because of the drivers used, the skill of the designer and their intent. If anything sad a generalization, larger cabinets tend to have greater low frequency extension. Openness has nothing to do with cabinet size.



None of this is accurate, it’s driver and designer influenced and I can give more examples of speakers that are the polar opposite of that you describe than speakers that fit your description.

I figured most the sauce is in the drivers themselves, surprised that the actual cabs don't have more generalization.

I do know as far as guitar cabs I haven't seen an open one I liked, with the same cream backs, the sealed ones sound fuller. But as you mentioned a small sample size would be over generalizing.

 

[MYLOWFREQ]

You can place a speaker in a box, and if you wire it correctly and feed it right, it will make a sound.

I've never designed a cab for a speaker, but I guess it's somewhat similar to treating your room acoustically. What's in theory won't completely match your objective measurements. And to make things more complicated, there might be different reasons to that. When it comes to designing a cab, the equipment you use to take the measurements and the room transfer functions in which you're taking the measurements in all play a role.

Long story short: I think having an acoustically treated room and a good equipment with low noise and a flat frequency response is harder than building the cab itself (I might be exaggerating it a little bit, but not by too much. )

 

[agedhorse]

You can place a speaker in a box, and if you wire it correctly and feed it right, it will make a sound.

I've never designed a cab for a speaker, but I guess it's somewhat similar to treating your room acoustically. What's in theory won't completely match your objective measurements. And to make things more complicated, there might be different reasons to that. When it comes to designing a cab, the equipment you use to take the measurements and the room transfer functions in which you're taking the measurements in all play a role.

Long story short: I think having an acoustically treated room and a good equipment with low noise and a flat frequency response is harder than building the cab itself (I might be exaggerating it a little bit, but not by too much. )

Designing a (properly designed) speaker cabinet is no different than designing a complex spring-mass resonant system, plenty of math behind the modeling software along with an understanding of what the equations mean.

Treating the room is more a matter of managing reflections and absorptions, again the math can become complex but very different from speaker enclosures.

I have designed both, mostly large public performance venues, and IMO there's a little more subjectivity in designing acoustic spaces and treatments. There are also things that simply can't be changed within a venue which makes the choices and budget more difficult.

 

[hbarcat]

How do cars even work? What does an engine do? How does all that affect my drive to work?

I'm not trying to be a smart ass, but your questions are incredibly complicated. Knowing the answers requires a significant investment in time and effort, which cannot possibly be achieved by reading a few internet posts.

Several others on this thread have linked to authoritative resources. I'm sure that more will be posted.

 

[davepen]

All sounds are about moving air, especially low frequency sound. Ported cabinets move more air, thus more sound.

Is it good sound or crappy sound? That’s where the math comes in.

 

[bass player 53]

whats the baffling do? how does that all affect the tone? i can read schematics but i still dont really understand physical sound design after the signal leaves the amp

Prompted by a five watt world video on the Ampeg B15

I can watch videos comparing 4x10 vs 1x15 or closed vs open back, but I still have a hard time with some vocabulary words like Baffling, and how that affects anything. I've also seen intricate double box designs from people building for their cars sound system -- how does sound travel through a box like that?

I might have a hard time understanding in text, but ive tried Google and YouTube and searching this forum. ANY help is appreciated, but a YouTube video is doubly so.

Bob Gallien, founder of GK, gives his thoughts about cabinets, among other things.

Cliff Engel | Interviews - Gallien-Krueger

 

[agedhorse]

All sounds are about moving air, especially low frequency sound. Ported cabinets move more air, thus more sound.

Is it good sound or crappy sound? That’s where the math comes in.

Ported cabinets don't necessarily "move more air", they "move air differently" which is why drivers for sealed cabinets are designed differently than for ported cabinets.