# who uses a closed back/front ported guitar cabinet?



## GTmaker (Apr 24, 2006)

HI folks
Coming from a "bass player background, the best sounding cabinets I ever used where allways closed back/front ported.
Why not for guitar ?
Who makes these cabinets and are they as good for guitar as they are for bass?
G.


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## greco (Jul 15, 2007)

Did you see this?
Guitar Cab Porting Question

I know that @mhammer has been interested in this approach to speaker cab design.

These are often mentioned in the Jazz Guitar Forum...


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## GTmaker (Apr 24, 2006)

thanks for the reply Dave...the linked article has way too much "techie talk" for my brain...
The cabinet pics are well in the range of what I was talking about.
Here are 2 pics of a "full" ported cabinet.
G.


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## Grab n Go (May 1, 2013)

Yup, I use closed back, ported 1x12 cabs. They perform as you'd expect. The low end is definitely enhanced. The bass control on most of my amps is usually dialled back as a result. Depending on the amp, that's actually a good thing.

But I do like open back cabs as well, especially for Fender combos.


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## greco (Jul 15, 2007)

My DV Mark Little Jazz (8 " speaker) is rear ported. I turn the bass EQ virtually OFF ...as do many others, apparently.


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## vokey design (Oct 24, 2006)

1 x 12 Speaker Cabinet by Stephenson Amplification
I have used these before, they are massive both in sound and size for a 1x12.


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## High/Deaf (Aug 19, 2009)

Three of my 112 cabs are closed back ported designs:

Mesa Thiele
Mesa widebody closed back
Sunn (Fender) 112 extension cab for T50C amp


Ported guitar cabs make a lot of sense because of the increased efficiency and the narrow b/w of the signal.


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## mhammer (Nov 30, 2007)

I just returned from picking up the tolex for a compact ported bass cab I am hoping to finish today or tomorrow. A quartet of 5" full-range Marsland drivers that purportedly go down to 60hz. The outside dimensions are 18 x 16 x 12. I'm using a slightly more complex port that has the air backflow from the speakers travelling about an extra 3 feet until they reach the opening on the front. It was based more on what could be physically achieved within the space with the wood (solid pine) than on any math. I just figured that the farther the longer wavelengths had to travel, the more they would be reinforced.

It's been a real bear to build, largely because there is a whole lot of I-have-to-do-this-before-I-can-do-that. For instance, the speaker jack is at the back. Running a suitable wire to the speaker leads requires that all the cotton sound-deadening stuff inside be attached first, but then the cable has to snake its way over and under things that, themselves, cannot be installed until the wire is. And of course, since I'm not going to tolex the inside, those surfaces along the bottom port that would be visible from the outside have to be painted before any cotton padding or tolex or interior structure gets installed. The list of this-before-that seems to get longer every day.

But I'll post as-it-gets-assembled pics when I'm done.

I was reading in_ Vintage Guitar_ magazine yesterday about the Tone Ring cabs that the blonde Fender Bandmasters and a few other models used for a short while. When you see their internal structure, you're impressed, but you quickly realize that, as brilliant as they were, they ran completely against Leo Fender's simple-to-build-and-simple-to-repair ethic. These guys make repros of the Tone Ring cabs and have more pics available.



http://beaverbottoms.net/tone_ring.jpg


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## KapnKrunch (Jul 13, 2016)

vokey design said:


> 1 x 12 Speaker Cabinet by Stephenson Amplification
> I have used these before, they are massive both in sound and size for a 1x12.


Ditto. I own one. Absolute keeper. Light enough to carry in one hand.

Also: A 2x12 cabinet that is 14"-16" deep will become a "detuned" cabinet by simply leaving one speaker out. Think of "detuned" as ported without being tuned to any specific freq (as ported cabs are). This offers the most complete freq response and virtually all the volume of two speakers. (According to tests by London Power)


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## rwe333 (Feb 18, 2006)

I used a Rivera TAC112 for years, always my fave cabinet. It's a Thiele-aligned dual front ported cabinet. I'm now using a slightly revised design of mine, build by a local woodworker. Very pleased, but very much designed around an ElectroVoice 200w EVM12L; I'm using the similarly designed Eminence EM12 right now. Good for clean or overdriven, very musical, easy to mic/record, projects like a (good) 2x12.


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## KapnKrunch (Jul 13, 2016)

GTmaker said:


> thanks for the reply Dave...the linked article has way too much "techie talk" for my brain...
> The cabinet pics are well in the range of what I was talking about.
> Here are 2 pics of a "full" ported cabinet.
> G.
> ...


If the vent across the bottom is equal in area to the speaker, then this is a detuned cabinet, not a ported cabinet.


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## Roryfan (Apr 19, 2010)

The matching cab for my Suhr Badger 30 is a closed back, front-loading 112 with 2 small front ports. I’ve tried many speakers in it but have never been 100% happy & tend to prefer some of my other cabs.


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## greco (Jul 15, 2007)

KapnKrunch said:


> If the vent across the bottom is equal in area to the speaker, then this is a detuned cabinet, not a ported cabinet.


That is interesting! 

Thanks for this info.


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## greco (Jul 15, 2007)

Roryfan said:


> The matching cab for my Suhr Badger 30 is a closed back, front-loading 112 with 2 small front ports. I’ve tried many speakers in it but have never been 100% happy & tend to prefer some of my other cabs.


I wonder if it can only sound optimal with the parameters of the speaker it was originally designed for?
Just a thought.


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## KapnKrunch (Jul 13, 2016)

greco said:


> That is interesting!
> 
> Thanks for this info.


Not only interesting but dead simple. The OP doesn't seem to be interested in a lot techie calculations. Me neither. Detuned works, but I have never experienced many other cab designs so my opinion is certainly not definitive.


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## Roryfan (Apr 19, 2010)

greco said:


> I wonder if it can only sound optimal with the parameters of the speaker it was originally designed for?
> Just a thought.


I bought the cab unloaded & believe the stock speaker is the WGS version of a V30. The first speaker I tried was a nicely broken-in MIE V30, which is what the stock speaker aspires to. It was OK but didn’t wow me at the time. 

Besides the V30 I’ve tried a vintage G12-65 (congested), a Scumback M75-PVC 65W version with the Nomex cone (NO bottom end at all, which surprised me), a Scumnico (nice & smooth but almost too polite) and a 30W Hellatone, which is a broken G12H30 70th Annie. The Hellatone is the best so far, it has the broadest range of frequencies but can be strident at times. Kinda wish I’d kept the UK V30 to A/B with the Hellatone.

The guy I bought the cab from said that he found it to be very sensitive to speakers, a G12M65 Creamback was very muddy but a G12H75 was incredible, which parallels my findings of the ‘80s G12-65 vs. 30W Hellatone.


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## KapnKrunch (Jul 13, 2016)

@Roryfan Dang, that's disappointing, eh? Especially from a brand name associated with excellence. Speakers make a huge difference but at least they should deliver good sound, if not exactly what you are looking for. I have a couple of Hellatone V30's in my Garnet combo. They are good, but I still swear by the AllTone 1250 if a variety of great sounds is what you need. YMMV.


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## tdotrob (Feb 24, 2019)

I use a Marshall 1933 closed back ported 1x12 with a 1983 g12-65 for band rehearsal for ease of carry and I love it. Best 1x12 I’ve run through after going through many. Love it


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## zdogma (Mar 21, 2006)

I've used both the Mesa and I have a 212 Z best. Both good cabs with enhanced low end tightness.


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## Roryfan (Apr 19, 2010)

KapnKrunch said:


> @Roryfan Dang, that's disappointing, eh? Especially from a brand name associated with excellence. Speakers make a huge difference but at least they should deliver good sound, if not exactly what you are looking for. I have a couple of Hellatone V30's in my Garnet combo. They are good, but I still swear by the AllTone 1250 if a variety of great sounds is what you need. YMMV.


The amp itself is great, esp. when plugged into a Derrick Bell 2061 (slant 212) loaded with a pair of early 70s G12H30s, so it may not be the fairest of comparisons. And I am keeping my eyes peeled for a G12H75.


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## TVvoodoo (Feb 17, 2010)

I dropped a 15R chassis into this old bass combo box, and put a 12" in there. Significant improvement on the low end, 
and I made the back end on pins so you can swivel it open closed. I like it closed better.

Ignore the guitar. Couldn't get rid of it fast enough, these things drive a guy to drink.


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## Spellcaster (Jan 7, 2008)

This box was a butchered mess when I bought it. The original 12's had been replaced by a set of 15" JBL's in off-round holes and someone had hacked a pair of vent holes in the front. I took the optimal enclosure dimensions for the JBL's from a plan on the Lansing Heritage forum, decided that the box was a bit undersize for the drivers, but might be better with a set of properly sized ports. I recut the holes for the 15's, created some port ducts , and did a bit of cosmetic refurbishing. It actually sounds quite credible now. The JBL's are K140 bass drivers, but driven with my vintage Twin Reverb for guitar or my Rumble 150 for bass, it sounds better than it's got any right to.

From past experience designing and building sub cabinets for vehicles, I've found it tough to predict what port sizes will sound good and properly load the speakers to get good power-handling. I got lucky on this box.


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## GTmaker (Apr 24, 2006)

KapnKrunch said:


> Ditto. I own one. Absolute keeper. Light enough to carry in one hand.
> Also: A 2x12 cabinet that is 14"-16" deep will become a "detuned" cabinet by simply leaving one speaker out. Think of "detuned" as ported without being tuned to any specific freq (as ported cabs are). This offers the most complete freq response and virtually all the volume of two speakers. (According to tests by London Power)


I got the same results one time when I left out the 10" speaker and closed the back from this cabinet.
The remaining 12" Canibus Rex sounded great by itself with the 10" detuned hole left by the 10" speaker.
G.


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## High/Deaf (Aug 19, 2009)

Great looking cab, @Spellcaster . But NO, I don't want to help you move it. 




KapnKrunch said:


> Ditto. I own one. Absolute keeper. Light enough to carry in one hand.
> 
> Also: A 2x12 cabinet that is 14"-16" deep will become a "detuned" cabinet by simply leaving one speaker out. Think of "detuned" as ported without being tuned to any specific freq (as ported cabs are). This offers the most complete freq response and virtually all the volume of two speakers. (According to tests by London Power)


It should have exactly the volume of two speakers, if the power is the same and the impedance is still matched. 

It is an internet myth that, those things remaining equal, 2 speakers will be louder than 1. I see it all the time, have seen the pseudo-scientific explanations and have never had anyone provide proof of it actually happening, because it defies the laws of physics. At least on Earth.


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## KapnKrunch (Jul 13, 2016)

Different story if the two speakers are separated sufficiently to produce a LARGER (not louder) acoustic field. Is this true? To my ears it is... but what do I know?


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## High/Deaf (Aug 19, 2009)

KapnKrunch said:


> Different story if the two speakers are separated sufficiently to produce a LARGER (not louder) acoustic field. Is this true? To my ears it is... but what do I know?


Just perception, power can't be lost or gained. If it seems to be louder somewhere (like on the periphery), you've made it quieter somewhere else (like directly in front). 

It isn't always that simple though. If you take a sealed box with 2 speakers, you may increase efficiency by unsealing the box (removing one speaker) and get a slight increase in level (nowhere near 3dB as I've seen claimed for multiple speakers). In the hi-fi world though, the trade-off in bandwidth flatness isn't considered worth it - that's where you see lots of passive radiators and hardly ever opened or detuned boxes.


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## KapnKrunch (Jul 13, 2016)

High/Deaf said:


> Just perception.


Yeah. Perception via a larger acoustic field. It's real, then. But not louder.

As far as the hi-fi world goes: I am with JB Welder. Audiophools. More stupidity there than with musicians, if that is possible.


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## High/Deaf (Aug 19, 2009)

KapnKrunch said:


> Yeah. Perception via a larger acoustic field. It's real, then. But not louder.
> 
> As far as the hi-fi world goes: I am with JB Welder. Audiophools. More stupidity there than with musicians, if that is possible.


LOL

My old mentor used to call it 'hi-futility'. He was highly technical and appreciated the tech but not the snake oil.

It is a joy to hear a really well-sorted out hi-fi system. A system that just lets you hear the music and place yourself in it. But some people go way beyond that with crazy non-technical gobbledy-**** that just is bragging rights at the stereo shop.

Hi-fi shopping used to be the worst experience ever, as well. It always started with "You want new speakers, what kind of electronics do you have?" To which, any answer that wasn't product they sold was deemed insignificant or downright damaging to the glorious speakers they were about to sell you. Man, what a dick measuring contest that used to be.

My mentor/boss also thought I was crazy for "still using tube amps". He also believed any distortion was bad (by definition, it is an undesirable artifact) - oh, we used to have some energetic rows over that one. LOL


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## mhammer (Nov 30, 2007)

One of my undergrad profs was Al Bregman, the godfather of what is termed "auditory scene analysis" ( Auditory scene analysis - Wikipedia ); the way that we assign all the stuff coming into our two ears to discrete sources and directions. (I think Steven Pinker and I were in his class together, during my final year at McGill). Bregman essentially applied many of the concepts of gestalt psychology - which was primarily a vision-oriented approach to perception - to the realm of sound. We're all familiar, even if intuitively, with many of the basic gestalt principles, such as the way we separate what lands on our eyes into "figure" and "ground", the way we "close" visual elements that are broken, the way we group things together that are close together and similar to each other, the way we perceive continuity in otherwise broken elements, and so on. The same things apply in sound. For instance, with the space between notes, how do we "know" it's coming from the same instrument, especially when there is substantial spacing between what the same musician played a little while ago, versus now? How do we hear this instrument coming from the left and that one coming from the right, especially given that we only have two ears and sound always bounces off surfaces to reach both ears? Why do we hear a steady and pitch-fluctuating copy of the signal as "chorus" (i.e., two musicians attempting the same series and timing of notes)?

Worth reading up on. It will also inform one's approach to sound image, fidelity, mixing and post-production, and a host of other aspects of sound in music.


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## Michael Baker (Jan 23, 2019)

I suspect that the reason you don't see more "hi-fi" guitar cabinets is the limited frequency range, and the very real "this is what the classic cabinets always were" prejudice against something new.
Acoustic/jazz amps often look to have "extended" frequency range so they have tweeters and larger "woofers" - some even have either crossovers or dedicated hi and low amplifiers.
Seal/Ported/Tuned cabinets are generally designed to produce better low frequency sound from a given speaker then to reenforce high frequencies. Some to the best guitar amps used 15" speakers to produce more low frequencies, but lost some of the highs - which is why Fender continued to use open backed cabinets for their combos.
I could see using a designed ported/tuned cabinet for an acoustic or jazz-oriented amplifier with a 10" speaker to get the lowest frequencies in a smaller package. 
The use of closed cabinets, especially the classic 4 x 12" and the 2 x 12" for Marshall and Fender was more to allow greater SPL's from the existing speakers than for any specific frequency design. While the 2 x 15" Blackface Bassman bottom produced a lower frequency, the sound at the fundamental frequencies was not that much more than the classic 4 x 10" combo.
Considering the reams of print that have been published about speaker design for "hi-fi", and how little that has actually been incorporated into "mainstream" guitar amp speaker design, it goes back to the basic limitations of the sound being produced.


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## Markus 1 (Feb 1, 2019)

mhammer said:


> One of my undergrad profs was Al Bregman, the godfather of what is termed "auditory scene analysis" ( Auditory scene analysis - Wikipedia ); the way that we assign all the stuff coming into our two ears to discrete sources and directions. (I think Steven Pinker and I were in his class together, during my final year at McGill). Bregman essentially applied many of the concepts of gestalt psychology - which was primarily a vision-oriented approach to perception - to the realm of sound. We're all familiar, even if intuitively, with many of the basic gestalt principles, such as the way we separate what lands on our eyes into "figure" and "ground", the way we "close" visual elements that are broken, the way we group things together that are close together and similar to each other, the way we perceive continuity in otherwise broken elements, and so on. The same things apply in sound. For instance, with the space between notes, how do we "know" it's coming from the same instrument, especially when there is substantial spacing between what the same musician played a little while ago, versus now? How do we hear this instrument coming from the left and that one coming from the right, especially given that we only have two ears and sound always bounces off surfaces to reach both ears? Why do we hear a steady and pitch-fluctuating copy of the signal as "chorus" (i.e., two musicians attempting the same series and timing of notes)?
> 
> Worth reading up on. It will also inform one's approach to sound image, fidelity, mixing and post-production, and a host of other aspects of sound in music.



This is incredible from a few vantage points:
1) To apply Gestalt theory to a physical science - (who'd have thunk?)
2) To have Steve Pinker as a class mate. (I'm reading "the stuff of thought" right now)

Fascinating - Thanks

Markus


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## mhammer (Nov 30, 2007)

Markus 1 said:


> This is incredible from a few vantage points:
> 1) To apply Gestalt theory to a physical science - (who'd have thunk?)
> 2) To have Steve Pinker as a class mate. (I'm reading "the stuff of thought" right now)
> 
> ...


If I occasionally show glimpses of cleverness, it's because Steve and I had a common education, up to a point.

Al was a phenomenal teacher. In one class, he had us emulate a CPU. We situated the desks in a large rectangle and each of us was assigned a function found in the architecture of CPUs at the time (1974-75). I think I was a buffer or the accumulator. Someone else was the arithmetic logic unit someone else was a shift register, and so on. We relayed the relevant bits to the appropriate person occupying the relevant function, after we had each done whatever action or transformation was our job. Not exactly gigahertz processing!  Quite the hour; complemented by study of Miller, Galanter, and Pribram's cognitive psychology classic "Plans and the Structure of Behavior", which dovetailed perfectly with the early days of artificial intelligence. Quite the set of classmates. One of them had been a volunteer, working with the famous Washoe the chimp. Ironically, that year my hour in his very "mentalist-friendly" class was followed immediately by a 3hr seminar with a hardnosed behaviourist, held in his office, while he told his secretary to hold all calls, and he'd lock the 5 or 6 of us in his office. One of those classes where you absolutely HAD to do all the assigned reading because there was no way to hide at the back of the class and avoid questions. Both highly worthwhile experiences. Steve wasn't in that one. I think I would have noticed him. 

Al is apparently still showing up to the office at the age of 80-something, though he doesn't teach anymore. His former faculty position is now occupied by Daniel Levitin.


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## Markus 1 (Feb 1, 2019)

Amazing experience 
A good teacher teaches life... not just subject matter. 
And now Levitin as a follower. Big boots following big boots


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## Frustrated Bassist (Apr 5, 2016)

GTmaker said:


> HI folks
> Coming from a "bass player background, the best sounding cabinets I ever used where allways closed back/front ported.
> Why not for guitar ?
> Who makes these cabinets and are they as good for guitar as they are for bass?
> G.


The 112 cabinet in the OP's photo is a bass reflex cabinet, specifically a 'mouth breather', which is exactly what it does. You sacrifice a bit of bottom end tightness and get more bass and low mids volume from the box. Half way between an open back and a sealed cab but the volume gain center is at a lowered frequency. More suitable for smooth than crunch but authentic for a 1960's - 1980's solo or bottom cab for every genre of music popular at the time (except where a Marshall is driving the guitar). From what I can see, I give that cab a '10', as a mouth breather. That is a perfect build for a 112 for guitar. Keep in mind that what comes out of the port is a millisecond delayed and altered version of what just came off the front of the cone. The port adds warmth and depth to the tone, with the focus on bass and low mids.
They are ideally used at floor level and generally not tilted, as they are technically a bass bin. They make great bottom cabs for Traynor, Fender, Vox, most or all Eminence speakers, Celestion 'H' magnet speakers but generally not so good if you want to drive Celestions hard or go high gain, as it will get sloppy. Celestion 'M' magnet speakers in one of these will give you vintage Vox but will have flabby bass at higher volumes. They also work well as a stand alone but how well is determined primarily by your gain/volume and cab tuning.
Vox made a 212 cab with a bottom port that was about 1/3 the cab height, the VR212 cabinet. Ampeg, Peavey and Traynor all made tall 412 mouth breathers in the 1970's - 80's The first mouth breather I ever used was an 80's Crate 212 solo and it took maybe three power chords to fall in love with it. When it comes to the 'traditional' Marshall sound or modern high gain, holes in your cab(s) is the last thing you want. You want the cab to be water tight for that.
The cab in the picture is 'proper', with the shelf and light damping material on the top and sides. If you pack the cab you are just robbing the port. The other side of that coin is that they can be boomy at volume but that resonance is part of the design principle and that is where tuning the cab with damping comes in. Dollarama comes in handy for that as they have different thickness' and densities of foam matting for a few bucks. That includes the interlocking foam mats they sell. For spun or batt damping, don't use fiberglass or Rockwool if you can avoid it. Spun polystyrene, etc, is the way to go now and is what all the manufacturers now use. The stuffing from a cheap Walmart pillow, etc. If you find you need to pack the box, you need a tighter bass response speaker, or it just isn't the right cab for what you are trying to do with it. No cab does everything.

Converted 1970's Peavey Classic 100 combo box. I removed and remounted the baffle/grill at the top and used the rear tube protection panel for the shelf. Loading it with a pair of 16 ohm Eminence/Fender blue label 100 watters which I am getting tomorrow. Currently loaded with a pair of 8 ohm Oxford 12T6-9's, which were Fender's stock 12's for pretty much everything in the late 1960's - early 1970's. I generally use it as a stand alone for guitar and bass with an Acoustic Model 250, 100w ss head and it works like a charm. These are the Bassman 12's, after all. It does see some action solo with my tube amps as well. It has 1/8" Dollarama foam matting stapled to the sides, a shelf/drawer liner I bought on a roll for maybe 3 bucks.
The speaker to its left is another mouth breather, a 1970's bass reflex bin, probably Radio Shack, made in Canada and OEM loaded with the same 15" Utah speaker that was used in the same period 15" Bassman cabs.


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## Frustrated Bassist (Apr 5, 2016)

TVvoodoo said:


> I dropped a 15R chassis into this old bass combo box, and put a 12" in there. Significant improvement on the low end,
> and I made the back end on pins so you can swivel it open closed. I like it closed better.
> 
> Ignore the guitar. Couldn't get rid of it fast enough, these things drive a guy to drink.


Tiesco Mosrite clone?


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## TVvoodoo (Feb 17, 2010)

Frustrated Bassist said:


> Tiesco Mosrite clone?


No some japanese off brand called Prestige


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## Frustrated Bassist (Apr 5, 2016)

TVvoodoo said:


> No some japanese off brand called Prestige


Yup, a Tiesco.








Prestige 1960s


Prestige Japanese made guitars in 1960s for St Louis Music, USA Images eBay: Images 1960s Made in Japan Prestige nylon string guitar courtesy of Mark Sivdas 26 Jun 22




jedistar.com


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## BMW-KTM (Apr 7, 2015)

I run a Thiele cabinet under my Mark V-35 to create a mini-stack.
It absolutely brings some power, tightness and focus/clarity to the bottom end along with a bit of a bump in overall volume which has the side effect of improving clean headroom if I want it. Not that it needs much improvement. For 35 watts you can get some surprisingly loud clean tones, more-so with the Thiele cab.

I replaced the MESA Engineering logo plate with a Boogie plate to match the amp.
I also replaced the nickel grille washers with black washers.
I think it's a much cleaner looking setup this way.

Pay no mind to the EQ sliders or knob positions. I had centred them all out to protect my top secret proprietary tone recipe  but after handling the rig some of them moved.


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## greco (Jul 15, 2007)

BMW-KTM said:


> I had centred them all out to protect *my top secret proprietary tone recipe*  but after handling the rig some of them moved.


Good one! LOL


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## BMW-KTM (Apr 7, 2015)

greco said:


> Good one! LOL


I actually centred them just for the express purpose of making that joke.
That's what a sick puppy I really am.


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