BJFE / BearFoot fx Guitar Effects Community

I would love to know more about the difference in tone between open and closed back cabs? Does anyone have experience with both kinds? I've always had open back. Feedback would be much appreciated. Thanks!

I have both in a 2x12 with vintage 30's.The differences are closed back is directional ,mids more pronounced and boomy where the open back fills the room and has a focused lowend.Closed back will give you that thump also.My drummer likes the open back so he can hear me better.

mfolet wrote:I have both in a 2x12 with vintage 30's.The differences are closed back is directional ,mids more pronounced and boomy where the open back fills the room and has a focused lowend.Closed back will give you that thump also.My drummer likes the open back so he can hear me better.

Thanks for the feedback mfolet! This seems to confirm what I've read on TGP. I guess I'll just have to hear one to tell if I like it or not.

I played nothing but open backed combos for years, & open back works well for most any situation, but there are a few caveats... You can somewhat tune the sound by careful placement from the wall behind an open backed cab. This works exceeding well if you have the time an inclination. What this does is aligns the sound waves coming from both the front & back of the speaker. Sometimes even an inch or two can make a huge difference in finding the sweet spot where the sound really comes together. If you do gigs & have minimal time to set up, or play large or outdoor venues where there is no wall behind you, then all bets are off for tuning this way. There are many options for open back cabs, including the size, shape, & location of the opening, as well as convertible cabs that have a panel that can removed for one cab that can be both open & closed back...
Closed back cabs always have the "wall" behind you in the same place. Some speakers work/sound better in closed back cabs. A few years ago I started hearing about "detuned" cabs, which are closed back cabs that have some speakers removed, & the open speaker hole effectively becomes a huge port for the sound coming from the back of the speaker to exit thru the front of the cab. A 4x12 cab would have 2 speakers removed, & rewired for the proper impedance. Kevin O'Connor of London Power was the first to research this & did copius amounts of research to find the ideal dimensions for various speaker configurations. Since all I played was open back combos, I had no way to experiment with "detuned" cabs until I found a product called the Sound Enhancer, which is basically an amp stand for a combo amp that's also a folded horn for the sound waves coming off the back of the speaker(s), effectively turning an open back combo into a detuned cab, as well as putting the wall behind you in the same place, & pointing the front of the speakers up towards your ears. I bought one used & it works exceedingly well. It changes the response significantly, so I needed to alter my normal EQ settings to accomodate the changes. The Sound Enhancers come in 5 sizes for various size combo amps...
Then there are ported cabs, with many schools of thought out there on the how dimensions, port size, & port location will improve response.
All of these options depend on what kind of music & tones you're after, and which speakers are used.

yeah, i an an open back combo guy.

and a closed back 4x12 or 2x12 cab guy.

even better to have BOTH onstage, and switch between them like eric johnson

Many years ago, I used to frequent a local blues jam/open mike, & the guy that hosted it had this absolutely phenominal sounding Super Reverb. While it was a mite overpowered for the tiny stage in this small club, it was one of the best amps I've ever heard. Because of the tiny stage, you had to stand right in front of the amp with the beatiful sound from the speakers blowing right past your ears about knee level. While playing onstage it sounded really bad, couldn't hear diddley squat, so no way to tell how it sounded out front. Early on I would reach around & turn it up a little in an effort to hear it better. BAD IDEA! Not only was it way too loud then, but it also took it out of the sweet spot where this amps mojo was... It was a hard lesson to learn. These days I can still play onstage when things sound terrible up there, & not having the benefit of a good mix via stage or in-ear monitors, but it helps tremendously to be able to hear what the amp really sounds like.

Cobra wrote:Many years ago, I used to frequent a local blues jam/open mike, & the guy that hosted it had this absolutely phenominal sounding Super Reverb. While it was a mite overpowered for the tiny stage in this small club, it was one of the best amps I've ever heard. Because of the tiny stage, you had to stand right in front of the amp with the beatiful sound from the speakers blowing right past your ears about knee level. While playing onstage it sounded really bad, couldn't hear diddley squat, so no way to tell how it sounded out front. Early on I would reach around & turn it up a little in an effort to hear it better. BAD IDEA! Not only was it way too loud then, but it also took it out of the sweet spot where this amps mojo was... It was a hard lesson to learn. These days I can still play onstage when things sound terrible up there, & not having the benefit of a good mix via stage or in-ear monitors, but it helps tremendously to be able to hear what the amp really sounds like.

Newarkwilder just snagged a '68 super reverb, 100% original, for less than half what a "vintage dealer" would sell it for

he is driving it here tomorrow, and it's going to my OWN mad genius amp guy here in florida, George Sholz. -- George was Harry Joyce's apprentice, and the inheritor of that trademark. He is a VERY GOOD amp tecnician, and he has the same passion for fixing amps that Bjorn has for making pedals and amps. They are very similar people, really.

Anyhow, George is gonna to the "typical" restoration job with his "private stock" parts (stuff he has collected since the 70s), and then do two modifications to the circuit to me it as exact a circuit as the 65 blackface super.

if George will let me, I will take pics and video of the process. George is very private, and I only bring COOL people to meet him, or have work done, because he will turn many people away if they have a bad attitude or he simply doesn't like their amp (he refuses to work on many pc board amps, mesas, etc......i don't blame him. it sucks to work on those)

But once it's done......that super....set with volume at 6...and the BJF pedals in front of it.....LOOK OUT.

i'm gonna bring my BJF board and demo it for George. he is HARD to impress. the skreddy i showed him barely piqued his interest. he has only made ONE fuzzpedal, because he has a stash of various OC series trannys he had kept from the 70s. I may take pics of it if he lets me. the inside is SO OVERBUILT it's almost funny. 5mm traces on the PC board, big WIDE traces, like an amp!

o good old fender super, set on 6, with a strat or a tele or a guitar with p-90s and a few good pedals is all a man REALLY needs in many ways

This is a really interesting read regarding speakers & directivity:

http://www.thegearpage.net/board/showth ... p?t=470956

Honestly- I think if you can manage it, its worth having both all the time. Right now, my "big gig" set up is just a Budda 18w (louder than a marshall 50 watt) 1x12 combo sitting ontop of an Orange 2x12 Combo. The Combo uses a Budda Fat70 I believe- its got a roundness to the treble and a nice full low end, all in the combo open back. The 2x12 has Vintage 30s in a closed back configuration which seems to produce a tighter and meaner low end, more aggressive mids and a more in your face treble since its unidirectional. I love my tone without the extension cab, but the way it adds live lets me feel like I'm cutting through a bit better. I'm not a speaker fanatic though- I could use some lessons and more knowledge on the subject as well.

While I'm far from an expert, I've been busy doing quite a bit of research & experimenting with cabs & speakers. After all, speakers are what we're hearing when we play electric guitar, the final link in the tone chain.

How speakers & cabs interact with the surrounding environment, which is never consistent, has a huge impact on what we actually hear. There are so many variables that can alter the sound, including the air in the room, placement of the cab in the room, where your ears are in the room, etc... Change one variable even the slightes little bit & you have a different sound.

I go thru these stages where I need to experiment with speakers & cabs, & since swapping speakers to find the best match is a realtively inexpensive way to improve your tone. It can be a huge PITA though, since it's time consuming, & true A/B comparos are impossible. Newer speakers generally need alot of time to break in, so any tone testing done won't yield accurate results unless they are broken in... Some folks are cool with whatever they have/use, end of story. There are many tried & true combinations that just work & make sense, ie Marshall plexi & 4x12 with greenbacks, or Fender Tweeds & Jesesn alnico's, etc... Mixing dissimilar speakers can be really cool, where one speaker can fill sonic territory that another is lacking...

I think it's worth the time to find good matches, plus it's fun! Especially if you're thinking outside the box of conventional wisdom, & are searching for alternatives to what's universally accepted. No different than trying/changing different guitars, amps, pickups, strings, pedals, etc, to find tones that work the best... There are a staggering amount of speaker designs available to achieve certain tones, & the same holds true for cab design. Trying to make sense of it all is daunting, & there is a lot of technical data to work with, as well as the usual amount of mumbo jumbo, hype, & mis-information. What works for some may sound awful to others, but it can be a good guide as a starting point.

Right now my experimenting is centered around finding the best speakers for my 5e3 Tweed Deluxe head, & a Marshall inspired 2x12 slant cab, as well as what works best for the LoMo in both the 2x12, and a 1x12 ported cab. I'm definitely looking for primo Marshall type dirtsounds, but cleanup is also paramount to me, so I search for speaker(s) that can do both without much dropoff in tone quality on either end of the spectrum. I'm inching closer to the ideal combinations, within my time & budget restraints, which is always a factor! LOL!!