Prospect floating block

[gnappi]

I have a Prospect "Custom Shop" with a full block and a user on another forum looking for info on the block and its actual purpose asked about the full vs. floating block.

Since mine has a full block, and potted SD 59's and I've never played a "standard" Prospect with unpotted Seth Lovers I could not provide an answer. I read one thread here and it seemed contradictory.

So if you good folks could answer:

Does the floating block provide better acoustic tone to the electrified sound? Yes/No

Does the solid block afford more feedback resistance? Yes/No

Is the floating block really much lighter? Yes / No

Even the Heritage page on the standard Prospect mentions the floating block but no mention as to its purpose.

Those questions seem to get myriad unclear answers on the web and I hope to get some straightforward replies.

 

TIA

 

 

 

 

 

[cobo]

The blocks in a semi-hollow guitar are designed to help shift and/or dampen the resonant peak frequency of the guitar body.   It helps to think about what's going on mechanically.

Fully acoustic guitars have a big, hollow wooden body that tends to amplify mechanical vibrations from the strings (resonate) at certain frequencies.  Depending on the body shape, what kind of wood, etc., different acoustic guitars sound different because they resonate at different frequencies.  You excite those resonant frequencies when you pluck the guitar string, or when sound waves strike the guitar body from elsewhere.  Hollow/Semi-Hollow electric guitar bodies are designed to resonate a little bit like an acoustic guitar, but most hollow-bodied guitars (like a Prospect) have a fairly shallow body, and so it doesn't resonate nearly as much as a "full" acoustic guitar with its deep body.  Nevertheless, if you play a Prospect unplugged, it will definitely sound "louder" than most solid body guitars because the hollow body of the Prospect has a lot less mass than a solid body gutar, and the solid body is also quite a bit stiffer.  Adding mass and stiffness will tend to push the resonance up to higher frequencies.  

Adding a block to a hollow-body guitar would tend to add more weight and stiffness to the body/pickup mounts, which drives the resonant frequency higher.  Just like tightening a string on your guitar; the resonant frequency of most things will increase when they get stiffer.  A floating block Prospect would probably resonate somewhere between a fully hollow Prospect and a "normal" block that is glued to the front and/or back of the body.  Different sound?  Yes.  Better/Worse?  Depends on what you like.

I also have a custom Prospect, but mine is fully hollow.  The acoustic (unplugged) sound is no-doubt different than yours - probably louder at some lower midrange frequencies because the body of my Prospect isn't as stiff/heavy as yours.  The guitar's vibrations get fed into the strings, and make them vibrate/resonate differently, compared to another guitar with different resonant frequencies.   So my Prospect would also sound different when plugged into an amp than yours.  Plugged in and playing at higher volumes with the amp creates a feedback loop where the mechanical air vibration (sounds) coming from the amp strike the body of the guitar, and excite the body resonance, which mechanically amplifies the amp's sounds.  The vibrating guitar body is connected to the strings, so any strings you're not touching start vibrating at their resonant frequencies, and the pickups amplify (electrically) what the strings are doing, and sends it back to the amp, which amplifies it some more.  It only takes a few tenths of a second for that "loop" to go out of control and the howling begins (to the joy or chagrin of the player/audience - depending on lots of other factors ...).  Placing your hands on the strings to dampen the vibration controls the amount of feedback.

A semi-hollow body with a block will be less likely to howl/feedback in the first place because it has shifted the resonant frequency of the guitar up and somewhat outside the sounds coming from the guitar strings.  But there are still some resonant frequencies in range, and you can get a semi-hollow guitar to feedback as well - you just need to turn up the amp louder, or stand closer to it.  A full solid-body guitar shifts that resonance even higher and is much harder to get the howling going because the body generally doesn't resonate as much in the same frequency band as the strings/sounds coming from the amp.  You can get a solid body to feedback, but that's because the strings and the pickups themselves have resonances that can get excited by really loud amps.

 

[cobo]

I should also add that my fully hollow Prospect is crazy-light-weight.  Great for your back and comfort, but some would even call it unbalanced because the neck outweighs the body.   When you're standing up playing it with a strap, the neck tends to fall towards the floor.  You have to hold the neck up with your left hand to keep the guitar level.  Not a big deal, but it is different than a normal guitar that has more even weight balance between the body and the neck.

[goSteelers]

I have a solid (full) block Prospect, and a floating block Prospect.  The floating block definitely has more acoustic hollow tone, does feedback sooner, but weighs about the same.  The weight is the same because the difference between full and floating is only about 1/8 of an inch.  The wood running down the center of a floating block Prospect does not touch the back (making it floating), but almost.

They both sound great, but I like the sound of the floating block better.  I would love to be able to compare them to a full hollow Prospect -- which I might like even better.  I thought about getting one of those, but I'm afraid that it won't sound "different enough" compared to my floating block, and might feedback too much.  With those concerns, I can't justify the price of one new, and they are so uncommon that you never see them used.

I like Prospects much better than a 335 size, which I consider uncomfortably large.  Even the Prospect feels a bit too large for me, but I found that making your strap a bit longer helps in that department.

To me, the ultimate Heritage dose not exist -- it would be a floating or full hollow Millie -- kind of like a floating or full hollow ES-Les Paul.  But -- the Millie is not a semi-hollow at all, it's a semi-solid (a topic discussed elsewhere), and ES-Les Pauls only come in solid blocks.

[cobo]

6 minutes ago, goSteelers said:

I have a solid (full) block Prospect, and a floating block Prospect.  The floating block definitely has more acoustic hollow tone, does feedback sooner, but weighs about the same.  The weight is the same because the difference between full and floating is only about 1/8 of an inch.  The wood running down the center of a floating block Prospect does not touch the back (making it floating), but almost.

They both sound great, but I like the sound of the floating block better.  I would love to be able to compare them to a full hollow Prospect -- which I might like even better.  I thought about getting one of those, but I'm afraid that it won't sound "different enough" compared to my floating block, and might feedback too much.  With those concerns, I can't justify the price of one new, and they are so uncommon that you never see them used.

I like Prospects much better than a 335 size, which I consider uncomfortably large.  Even the Prospect feels a bit too large for me, but I found that making your strap a bit longer helps in that department.

To me, the ultimate Heritage dose not exist -- it would be a floating or full hollow Millie -- kind of like a floating or full hollow ES-Les Paul.  But -- the Millie is not a semi-hollow at all, it's a semi-solid (a topic discussed elsewhere), and ES-Les Pauls only come in solid blocks.

I'm 100% with you.  My fully-hollow Prospect is very "lively" and responsive, and sounds great.  It's very similar (tonally) to an H530 that I played at Wolfe Guitars while on vacation in Florida last year (my Prospect also has Lollar P-90s, like a '530).  But the most comfortable-to-play guitar I own is my H140, which is even a little bit smaller than the H150/Les Paul.  I think I would really like a fully hollow H140/H150/Les Paul-ish sized body.  Or, perhaps something with a minimally-sized floating block to tame the feedback (I do find my Prospect is a little too lively sometimes ...) and help even-out the weight distribution.

 I played some of the ES-Les Pauls last year and for whatever reason, they didn't excite me.  Might have been the semi-hollow construction, might have been the pickups, etc.  

[cobo]

Just realized I mis-typed something in my original explanation.  Adding mass (without changing stiffness) will usually shift the resonance to a lower frequency.  Adding stiffness (without changing mass) will shift it to a higher frequency.  The block in a Prospect changes the stiffness more than the mass, and that stiffness increase (that shifts the resonant frequency up so that it's more outside the range of the string vibration) is the dominant factor that helps control the feedback issue.

[FredZepp]

If you haven't seen it, there is a section of the video showing making Heritage semi-hollow bodies that illustrates the difference between a semi hollow with a solid block and one with a floating block.  

The floating block just eliminates a small piece of patch wood...  

Here is the video starting at that section...

 

[big bob]

2 hours ago, cobo said:

I should also add that my fully hollow Prospect is crazy-light-weight.  Great for your back and comfort, but some would even call it unbalanced because the neck outweighs the body.   When you're standing up playing it with a strap, the neck tends to fall towards the floor.  You have to hold the neck up with your left hand to keep the guitar level.  Not a big deal, but it is different than a normal guitar that has more even weight balance between the body and the neck.

My full hollow prospect has a bigsby that adds just enough counter balance to fix this problem!

[Kuz]

My 525 was fully hollow (base-plate tuneamatic bridge) and didn’t have any neck dive with a strap while standing.  If I played a guitar that had the neck dive like described, it would be a dealbreaker for me.

I play all my electrics with a strap while standing and I hate neck-diving guitars.

[goSteelers]

20 hours ago, cobo said:

I'm 100% with you.  My fully-hollow Prospect is very "lively" and responsive, and sounds great.  It's very similar (tonally) to an H530 that I played at Wolfe Guitars while on vacation in Florida last year (my Prospect also has Lollar P-90s, like a '530).  But the most comfortable-to-play guitar I own is my H140, which is even a little bit smaller than the H150/Les Paul.  I think I would really like a fully hollow H140/H150/Les Paul-ish sized body.  Or, perhaps something with a minimally-sized floating block to tame the feedback (I do find my Prospect is a little too lively sometimes ...) and help even-out the weight distribution.

 I played some of the ES-Les Pauls last year and for whatever reason, they didn't excite me.  Might have been the semi-hollow construction, might have been the pickups, etc.  

Or the issue with the ES-Les Paul may have  been the notion that they have lost interest in being a quality musical instrument company.  They are closing their Memphis facility, and the just discontinued the DAW product line that they own, Cakewalk, stating that they have now adopted a "strategy that is heavily focused on growth in the global consumer electronics audio business".

[tulk1]

On 1/7/2018 at 9:04 AM, goSteelers said:

To me, the ultimate Heritage dose not exist -- it would be a floating or full hollow Millie -- kind of like a floating or full hollow ES-Les Paul.  But -- the Millie is not a semi-hollow at all, it's a semi-solid (a topic discussed elsewhere),

They are out there. You just have to hunt for them. I've had an original hollow Millie, someone else here ordered one (when ordering customs was affordable) and I know a couple others have been posted. The big difference here, and that may be what you're saying, is they aren't the production Millie that we see now. More of like small Eagles or something. But, they do have the Millennium name on the inside. 

[LittleLeroy]

On 1/7/2018 at 8:04 AM, goSteelers said:

But -- the Millie is not a semi-hollow at all, it's a semi-solid (a topic discussed elsewhere), and ES-Les Pauls only come in solid blocks.

Can you please post a link to the discussion you refer to?  I'm very eager to understand how a Milliennium is not a semi-hollow guitar.  Thanks!

[goSteelers]

7 hours ago, LittleLeroy said:

Can you please post a link to the discussion you refer to?  I'm very eager to understand how a Milliennium is not a semi-hollow guitar.  Thanks!

There are a number of posts about this -- I imagine that searching for the word "kerfing" would find them.

Briefly stated, a Millie is made by routing out a solid piece of wood.  Kind of like a "weight relieved" Les Paul, with the maximum amount of wood removed.  There are a number of other guitars that claim to be semi-hollow that are made this way (e.g. Carvin, Epiphone ES-Les Pauls, Thinline Telecasters, PRS,  etc).  I consider them semi-solid -- they are not as "acoustically resonant" as a true semi-hollow.  Their sides are relatively thick, they weigh more, etc.   A true semi-hollow -- like  an ES-335, Prospect, etc -- is made by attaching separate, thinner (usually laminate) pieces of wood together using kerfing, much the same way an acoustic guitar is built.  The result is a guitar with significantly more acoustic resonance than a semi-solid.  The difference is very noticeable.  I would guess that building a true semi-hollow is much more labor intensive than building a semi-solid, and that's why manufacturers build semi-solids and label them as semi-hollows.

[skydog52]

Here is a picture of what they do. The middle part of the "sandwich".

 

[LittleLeroy]

11 hours ago, skydog52 said:

Here is a picture of what they do. The middle part of the "sandwich".

 

 

Thanks Paul.  Yes, I have seen that pic b4.  Would you describe this as "semi-solid"?  

[skydog52]

4 hours ago, LittleLeroy said:

Thanks Paul.  Yes, I have seen that pic b4.  Would you describe this as "semi-solid"?  

I would say it is a semi-hollow. Especially because since Heritage calls it a semi-hollow. 

Semi-solid is new to me.

Probably a discussion for another thread. Now this one is off subject.

[CJTopes]

I ordered my prospect with a solid block. Somehow that was forgotten and I got a floating block. After playing it I liked the sound so much that I kept it. I have a CS336 that has the solid block and I prefer the floating block. It is more acoustic sounding and it will feedback at high volumes. But,, you can get to that spot where the guitar responds to the amp at a lower volume. Excellent sustain!!! Nice and light too.....

 

[Gitfiddler]

Great photo, CJ!

 

If I order another custom Heritage semi, it will have floating block construction.  Maybe a Millie Pro with F-holes...Hmmmm.

[LittleLeroy]

On 1/7/2018 at 7:15 AM, cobo said:

The blocks in a semi-hollow guitar are designed to help shift and/or dampen the resonant peak frequency of the guitar body.   It helps to think about what's going on mechanically.

Fully acoustic guitars have a big, hollow wooden body that tends to amplify mechanical vibrations from the strings (resonate) at certain frequencies.  Depending on the body shape, what kind of wood, etc., different acoustic guitars sound different because they resonate at different frequencies.  You excite those resonant frequencies when you pluck the guitar string, or when sound waves strike the guitar body from elsewhere.  Hollow/Semi-Hollow electric guitar bodies are designed to resonate a little bit like an acoustic guitar, but most hollow-bodied guitars (like a Prospect) have a fairly shallow body, and so it doesn't resonate nearly as much as a "full" acoustic guitar with its deep body.  Nevertheless, if you play a Prospect unplugged, it will definitely sound "louder" than most solid body guitars because the hollow body of the Prospect has a lot less mass than a solid body gutar, and the solid body is also quite a bit stiffer.  Adding mass and stiffness will tend to push the resonance up to higher frequencies.  

Adding a block to a hollow-body guitar would tend to add more weight and stiffness to the body/pickup mounts, which drives the resonant frequency higher.  Just like tightening a string on your guitar; the resonant frequency of most things will increase when they get stiffer.  A floating block Prospect would probably resonate somewhere between a fully hollow Prospect and a "normal" block that is glued to the front and/or back of the body.  Different sound?  Yes.  Better/Worse?  Depends on what you like.

I also have a custom Prospect, but mine is fully hollow.  The acoustic (unplugged) sound is no-doubt different than yours - probably louder at some lower midrange frequencies because the body of my Prospect isn't as stiff/heavy as yours.  The guitar's vibrations get fed into the strings, and make them vibrate/resonate differently, compared to another guitar with different resonant frequencies.   So my Prospect would also sound different when plugged into an amp than yours.  Plugged in and playing at higher volumes with the amp creates a feedback loop where the mechanical air vibration (sounds) coming from the amp strike the body of the guitar, and excite the body resonance, which mechanically amplifies the amp's sounds.  The vibrating guitar body is connected to the strings, so any strings you're not touching start vibrating at their resonant frequencies, and the pickups amplify (electrically) what the strings are doing, and sends it back to the amp, which amplifies it some more.  It only takes a few tenths of a second for that "loop" to go out of control and the howling begins (to the joy or chagrin of the player/audience - depending on lots of other factors ...).  Placing your hands on the strings to dampen the vibration controls the amount of feedback.

A semi-hollow body with a block will be less likely to howl/feedback in the first place because it has shifted the resonant frequency of the guitar up and somewhat outside the sounds coming from the guitar strings.  But there are still some resonant frequencies in range, and you can get a semi-hollow guitar to feedback as well - you just need to turn up the amp louder, or stand closer to it.  A full solid-body guitar shifts that resonance even higher and is much harder to get the howling going because the body generally doesn't resonate as much in the same frequency band as the strings/sounds coming from the amp.  You can get a solid body to feedback, but that's because the strings and the pickups themselves have resonances that can get excited by really loud amps.

 

nice post cobo!  

May I just say that IMNTBHO the Milliennium is a semi-hollow body, while the other guitars using kerfing are hollow body  guitars with an added center block whether "floating" or "full".

[cobo]

nice post cobo!  
May I just say that IMNTBHO the Milliennium is a semi-hollow body, while the other guitars using kerfing are hollow body  guitars with an added center block whether "floating" or "full".

I wouldn’t argue against that statement, but usually ES-335s and the Heritage equivalent 535s are listed on guitar websites under the semi-hollow category. Some other sites list them as hollow body. Makes it hard to find what you’re looking for sometimes! [emoji41]


Colm

[goSteelers]

11 hours ago, cobo said:

I wouldn’t argue against that statement, but usually ES-335s and the Heritage equivalent 535s are listed on guitar websites under the semi-hollow category. Some other sites list them as hollow body. Makes it hard to find what you’re looking for sometimes!


Colm

I don't know that it matters what you call them, just that one understands that, generally speaking, a guitar that starts as a solid piece of wood, then routed out, will not have as much "acoustic resonance" as one made with separate thin pieces of wood and kerfing.   And within  the latter group, the least amount of wood block on the inside, the  more acoustic resonance it will have (full, floating, none, in order of increasing resonance).   And more acoustic resonance generally means more prone to feed back. 

We don't buy guitars based on  how they are made or what they are called, but  how they sound (among other factors).  So perhaps the right approach is to determine the sound you want, and buy that type of guitar, whatever that is.  I would strongly suggest that anyone looking for acoustic resonance in a guitar try all the various construction methods to hear the difference for themselves.  And play them at your normal level, because  they will definitely feedback differently.  For me, the "more hollow", the more I like it, but there are other factors to consider -- even though I own floating and full block Prospects, and I like the sound of the floating block Prospect the best, the guitar I play the most is a Millie, because  the larger body size on the Prospects is not  as comfortable to me.  But I would buy a full hollow Prospect too, if I could find a good deal on a used one.

[kidsmoke]

56 minutes ago, goSteelers said:

I don't know that it matters what you call them,

well, it matters in that the terms Solid body, hollow body, semi-hollow body have 70 years of history as established terms with specific construction characteristics allotted to them. While later technological advances in production may have allowed for hybrids of those characteristics to muddy the waters, those terms are still, in 2018, squarely attributed to a construction method. 

I don't disagree that a Millie seems to meet our modern sense of semi-hollow moreso than a 535/335, characteristically. The term semi-hollow is for a kerfed, laminated thin bodied guitar with center block. The Millie is the outlier, based on method and industry definition. That MAY change, but it has yet too. Just look at out beloved Heritage website. 

 

[LittleLeroy]

"The Gibson ES-335 (and the closely-related ES-345 and ES-355) remains a special instrument in guitar history. They are acknowledged as the first ‘semi-acoustic’ electrics ever made, and have been in constant production since 1958. The design and sounds they offer confirm their position as one of the most versatile guitars ever made."

"Gibson design legend Ted McCarty felt the ES-335 was right behind the Les Paul solidbody as his most important body design. “I came up with the idea of putting a solid block of maple in an acoustic model. It would get some of the same tone as a regular solidbody, plus the instrument's hollow wings would vibrate and we'd get a combination of an electric solidbody and a hollowbody guitar.” All guitar players owe a debt to Ted McCarty’s vision."

It would seem, although I haven't found 'evidence' to support the idea, the the term "semi-hollow" came from the marketing department who were searching for a way to sell the new design, which was, as history shows, a stroke of McCarty genius.  They seem to have felt that the term "semi-acoustic" wasn't going to get the job done.

"Semi-acoustic model

Gibson released the ES-Les Paul in 2015. It is a semi-acoustic model with f-holes and two Alnico humbuckers. The neck is mahogany, but the sides and back are laminated maple and poplar. A mahogany block runs throughout the body to increase sustain."

In my again NTBHO, the Millie is another breakthrough semi-acoustic design, using carved solid pieces rather than laminated top, back and sides, and a 1/2 center block and rim carved or routed from the same piece of wood.   

[Yooper]

The semi-solid frame is what defines the Millie family best. Too many other dissimilar guitars are semi-hollow and semi-acoustic. 

[LittleLeroy]

13 minutes ago, Yooper said:

The semi-solid frame is what defines the Millie family best. Too many other dissimilar guitars are semi-hollow and semi-acoustic. 

Have you offered this idea to Heritage's marketing department?  Might be more acceptable coming from a MI guy rather than a PA guy...  :-)