Dirty-South Blues Harp forum: wail on! > side vents
side vents
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asterix135
6 posts
Oct 11, 2012
1:19 PM
I recently got my first Marine Band, and I'm wondering what purpose the side vents on the cover plates serve.

As far as I can tell, they

1) Make it harder to create an airtight cup
2) Make me leak air into my mouth when I'm tongue-blocking the 2-draw
3) Redirect some of the sound away from anyone listening in front of you and dissipate it out the sides

None of which seem particularly like good things.

But these seem to be a selling point on some harps, so I figure there must be something good about them.
Adam Hamil
50 posts
Oct 11, 2012
1:43 PM
I love the side vents!!!! They allow me that much more variation in my tone. I"ve never had much of a problem cupping them. I usually TB out of the left side of my mouth on the 1 and 2 holes, so i don't have that problem either.

They add a brightness to the tone that some people love and some people hate. I've also noticed that the vents seem to make the harp louder then non-vented harps.
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C. Adam Hamil
HOHNER CERTIFIED Free Reed Instrument Technician
Milsson
40 posts
Oct 11, 2012
1:58 PM



Last Edited by on Oct 11, 2012 2:02 PM
SuperBee
618 posts
Oct 11, 2012
1:52 PM
Definitely louder and brighter. Asterix, I think your point 3 is imaginary. I also don't understand your point 2; how could a vent on the cover make air leak into your mouth?
As for an air tight cup, well I don't know. What I do know is that it didn't seem to give L'Walter too much trouble.
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arnenym
79 posts
Oct 11, 2012
2:07 PM
I'm a no vent lover. The vents do not make the harp louder, just brighter.
I have done tests on special 20 with drilled holes in the short sides if the covers. No changes in volume but the brighter sound cuts through the mix better. A disadvantage is that they also gives feedback issues when you amplify the harp. If you're not very good at cupping and got big hands/long fingers..
Marine Bands is for other reasons a louder harp It is not the vents. If you want it even louder you could try a Hetrick Bamboo comb or a Dick Sjoeberg comb. It makes a big difference.
BTW. I seal the side vents on my MB's ;)

Last Edited by on Oct 11, 2012 2:15 PM
STME58
259 posts
Oct 11, 2012
2:27 PM
From a manufacturing perspective, the vents allow the metal to draw into the die easier and allows the compound rounded corners at the front so a Marine band doesnt have the seams in the front corners like a Lee Oscar does.

Last Edited by on Oct 11, 2012 2:28 PM
walterharp
956 posts
Oct 11, 2012
2:30 PM
yup, I am a side vent sealer. But can play either way. I think that it is probably somewhat of a myth that it is louder with the side vents.. Louder to the player maybe because more sound goes that way, but less is directed to the mic without a tight seal, and it is easy to get a loose seal to alter tone with the side vents plugged. Joe Speirs suggests a small piece of electric tape on the inside if you want it sealed, which works well and has no cosmetic effect
asterix135
7 posts
Oct 11, 2012
2:32 PM
Super Bee -

My point 2 comes from tongue blocking on the right side of my mouth (I seem to have coordination problems when I try tongue blocking on the left side). When I'm doing that, my top lip is over much of the top cover plate, and my mouth is kind of wrapped around the left side of the harp. Without side vents, things are sealed off nicely. With the side vents, when I inhale, air comes into my mouth through the side vent, since I don't seem to be able to seal off that hole. Maybe I need to adjust my lip position?

Adam - how do you get variation in tone? Is it something to do with hand vibrato and the holes?
ElkRiverHarmonicas
1327 posts
Oct 11, 2012
3:29 PM

Last Edited by on Oct 12, 2012 5:52 AM
SuperBee
619 posts
Oct 12, 2012
4:24 AM
Interesting info David. But why do you start with "it has nothing to do with any of this"?
What has nothing to do with what?
Just seems a weird way to insert into a discussion. Do you mean "you cats have no idea what your talking about"?
I mean I could understand that, but the OP asked what is the purpose of side vents.
Most posters said they change the tone. A couple said the make louder. We were told it doesn't make loud, changes tone.
Then you chime in with it has nothing to do with any of this, and proceed to tell us that side vents change the tone. Oh but not just a change in tone. Overtones. Yeah ok. So a change in...sound. As distinct from...tone

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Last Edited by on Oct 12, 2012 4:26 AM
ElkRiverHarmonicas
1329 posts
Oct 12, 2012
5:55 AM
I was talking about this:
"Redirect some of the sound away from anyone listening in front of you and dissipate it out the sides"
Didn't mean to come off like an ass.




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David

____________________
At the time of his birth, it was widely accepted that no one man could play that much music so well or raise that much hell. He proved them all wrong.
R.I.P. H. Cecil Payne

Adam Hamil
51 posts
Oct 12, 2012
6:41 AM
@ astrix135 What I mean is that the vents give me more tonal options. I can chose to cover the entire back and vents for one tone, or just the back and not the vents for a different tone. I could just block the left side vent, or just the right side vent. w/o the vents you don't have alot of these options. I like to be able to cater my tone to each song.

@David I completely agree that the vents allow certain overtones to be present. Or take certain ones out. IMO the ability to control your overtones is a major factor in creating the correct tone for the song. This is also very important when playing and trying to blend with other musicians.
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C. Adam Hamil
HOHNER CERTIFIED Free Reed Instrument Technician
robbert
147 posts
Oct 12, 2012
6:48 AM
Great information. Thanks for the discussion. David, I'm glad I read your earlier post before the edit. Lots of good info and history there.

As with many threads on the forum, this brings my awareness to something about the harmonica I had not thought much about previously.

The entire subject of tone, tuning, and how the harp sounds in relation to other instrument during the performance of a song is becoming increasingly more important to me.
SuperBee
620 posts
Oct 12, 2012
7:11 AM
No no I'M sorry. Didn't mean you should delete the whole post. It was full of interesting info.
If billy shines was still here, he would tell you what's up with me, as he told us all so often. And in my case this time he would be 100% correct. I'm workin on it.
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isaacullah
2146 posts
Oct 12, 2012
8:04 AM
Here's the link to Dave's site on side vents: http://elkriverharmonicas.com/harp_school/1890s

There is some really fascinating info there, and I totally think Dave has it right on the money about what side vents add to the tone of a harp.

I also think, however, that they do make it harder to get a tight seal for those of us with out SBWII sized hands! Lol! For that reason, I've come to the conclusion that for me, non-vented covers make for a better amped tone. I wonder if the reduction in overtones from non-vented harps also makes for a difference in the amped tone too? Tube distortion is well known to add it's own set of overtones. Is there some "magic" in the combination of overtones from vented harps and those from the tubes, or does it clash? In my own, extremely subjective opinion, I hear the amped tone of non-vented harps as being more "compressed", "focused", and "dark", and the amped tone of vented harps as being "wider", "brasher", and "brighter". I don't presume to answer this question for everyone, but these days, I'm personally liking the more focused tone of non-vented harps....

As a side note, there is a way to hold the harp, shown to me by Dan Kaplan, that basically negates the side-vents. You use the left hand with the thumb open and wrapping around your chin and mouth like a megaphone (the same thing you do when you want to yell across a canyon or something), and the right hand like a flap that seals off the other side. In this way, you can make a vented harp get a much more focused sound. I haven't found a way to also hold on to, let alone to cup, a mic while using this grip, so it's purely for acoustic playing for the time being...
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Greg Heumann
1813 posts
Oct 12, 2012
8:00 AM
I have relatively small hands. I can get a full deep cup and am told I have excellent amplified tone with my Seydel 1847's - however I cannot get a full cup on a side-vented harp. I like them OK for acoustic work, NOT for amplified.
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GMaj7
111 posts
Oct 12, 2012
8:25 AM
At SPAH, Bertram from Seydel demonstrated something pretty cool... Using a non-vented harp, he was able to generate a sound from a reed at the opposite end of the harp. Not that I could replicate this, but it was interesting. He said that vents on the side allow just enough air to escape so this extra tone doesn't pop out unintentionally. Even on his full-length Session style covers, he had cut or drilled small vents.
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Greg Jones
16:23 Custom Harmonicas
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walterharp
957 posts
Oct 12, 2012
10:49 AM
Looking at Daves cool info on side vents and the Harrision harmonica patent linked there
http://elkriverharmonicas.com/yahoo_site_admin/assets/docs/US20090308223.126173637.pdf

is pretty interesting stuff!

thanks for the cool site Dave
ElkRiverHarmonicas
1330 posts
Oct 12, 2012
11:06 AM
Here's a better one than the one I had:

At Harrison, we spent a great deal of time studying the dynamics of side vents during the R&D phase. When I got there, I soaked it all up and talked to Brad for hours about what he'd discovered in the science of side vents. That research was far more detailed than I'm relaying here, or even that I remember.
I think it was probably the most comprehensive study of side vents that had been done since Richard Seydel Sr. was working on it in the 1890s. His original Bandmaster design was closed in the back and air came in from four side vents. The bottom side vents were funnel shaped - and they worked as air funnels, not sound megaphones as commonly thought. Jacob Hohner spent a great amount of time - also in the 1890s with a different tonal concept that created a side vent by default on the Mouse Ear Marine Band. All that went into the really unique side vent the B-radical had.
Now before I started working for Harrison, I spent about a year studying side vents myself. Harrison's data was obviously a lot more scientific than mine and Brad came to more detailed conclusions than I did, but in the end, we came to the same conclusion -

Side vents have nothing to do with sound. The change in tone is from the reed itself. The difference is air flow. When you change anything about air flow, you change the tone of the harmonica. This is the primary reason embossed harps have embossed tone, you change the airflow. One of the things specifically outlined in the B-radical patent was the airflow.

One interesting thing about side vents. With a side vent, it doesn't change the tone that's already there. It adds overtones. If you've got a good ear, you can hear this by blocking and unblocking the side vents. First try blocked, then unblock. As you open the vents, the original tone you had is still there, but there are specific overtones added to it.

There was a question presented a few years ago if side vents really did change the tone at all. I did a sound test where recorded a single note with me blocking and unblocking the side vents with my thumb and another recording of me just moving my thumb back and forth near the sound vents, but not actually getting close enough to block. I put it up on the site and all of the several dozen people who wrote in correctly identified there was a change in tone on the one where the vents were actually blocked.

One of my findings was that side vents affect tone more on the draw reedplate than the blow reedplate, because the air comes into the draw reeds deeper inside the coverplate (if you are looking in from the back). It's not quite as pronounced as you might think and I'm not sure I could really expect anybody really to hear it, but I can hear it.

If you are testing side vents, the modern Marine Band actually has the least significant side vent of any. The side vent isn't big enough. If you want to hear something obvious, do your testing on a prewar Seydel Bandmaster or Prewar Hohner Mouse Ear Marine Band.

This is only one of the many, many things we discuss today - and a lot of them 'modern' advances, that were well understood in the 19th Century. If you spent enough time looking at old patents, catlogs, etc. you'll see them. The basic concept of the Suzuki Overdrive is one that was done in the 19th Century. The Turbolid is another. The 19th century version of the Turbolid was a Seydel development in, I think, the 1890s. It was metal, but you snapped it on and off just like a Turbolid and it had a similar rounded shape.
I could go on and on with these.

If you read the B-radical patent (linked to above) you'll see three pages of drawings and a hell of a lot of text devoted to side vents and airflow. The B-radical side vent was designed specifically to be a variable side vent. All you had to do was cup it tightly and you've closed the vent.
Thus, you could go from vented to unvented in a single solo to change your tone.

Last Edited by on Oct 12, 2012 4:38 PM
MP
2506 posts
Oct 12, 2012
12:31 PM
Very good post Dave! i'm a big fan of side vents and my sweetest sounding MB is a mouse ear. giant side vents.
i experimented putting side vents in Special 20s (ala Kinya Pollards instructions) but didn't notice any difference in tone. (of course i opened the backs too.) i did about five or six and a couple of LOs to boot.

according to your post i suspect those oblong pill shaped vents are just too bloody small to make much of a difference.
Thank you for sharing your knowledge. Mark


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groyster1
2047 posts
Oct 12, 2012
2:36 PM
I have had many special 20s and mb1896 backs opened....it most definitely increases the volume....but side vents...maybe not....
ElkRiverHarmonicas
1331 posts
Oct 12, 2012
4:19 PM
There is no question in my mind about side vents giving more tone. I can quantify this added tone with a blocked/unblocked vent - that when the vent is unblocked, there is not only the tone that was there when it was blocked, but addition overtones that come in, mostly treble. The only real question is, is it a tone that you like. It is OK not to like certain tones.

This is one of my favorite things to talk about, the 1890s tonal revolution. I hunger for knowledge about it. Even after years of studying it, I don't know 1/10 of what I want to know. I really need Seydel's Bandmaster patent, but I can't find it. Richard Seydel Sr. invented the side vent. Just because Jacob Hohner's mouse ear Marine Band had a de-facto side vent doesn't mean he invented it. He wasn't thinking about air at all. There is no doubt in my mind that much of the tonal change Jacob Hohner heard was due to air flow changes. That's doesn't mean his concept was not valid. I think it was brilliant. I think Richard Seydel Sr., Jacob Hohner and Brad Harrison are the three most brilliant harmonica designers ever. They are the Triumvirate of revolutionary harmonica design - the obvious main difference being two of them were descended from people who had already created large harmonica companies.

Jacob Hohner invented another concept, the idea of the coverplate as a sounding board. The ENTIRE idea of the Marine Band - the mouse ear as he invented it - read the patent to see Jacob's own words (translated into English) on it. Pat Missin downplays that somewhat on his site and it's one of a very few things Pat and I respectfully disagree on about harmonica history. He makes a valid point about it, but I don't agree with it. I think Jacob Hohner's was a very valid concept. His idea was minimize all points of contact with the reedplates, so the coverplates could resonate more freely as a sounding board - kind of like how a guitar works. Pat's contention is that there isn't much vibration in the coverplates. After all your hands deaden it, right?
Well, if you lay a tooth on the coverplate as you play a note, you will feel the vibration on your tooth. It is true that when you cup it tightly, the vibration is diminished, but it is still there. You can also test Jacob hohner's theory by gripping your harmonica tightly, then remove that grip (while keeping the back open) and seeing if there is a change in tone. It seems very obvious to me, but I understand not everybody can hear it. I can hear it.

I also did an experiment on a wood table once. I put my ear on the table, then tapped it on the side away from my ear. I could hear the vibrations traveling through the table. Then I am six feet, two inches tall and 240 pounds. I laid my whole body on the table and did the same thing. The vibrations still traveled through the table to see how they would travel with my body on the table - thus deadening like your hands on a harmonica coverplate would and the tapping could still be heard just as loudly. These are the things we do at the Elk River Institute for Advanced Harmonica Studies so you don't have to.

So, some are thinking, well how does resonate from the coverplate if your hands are covering the whole dang things? Well, your hands are not covering it all. They can't. Half of the coverplate surface is INSIDE the harmonica. Even theoretically, the most you could dampen would be half of the surface.

So, next question on the minds of non-believers, well, Dave, if this is true, why is there not more difference between the tone of the vented Marine Band and the tone of the old, handmade Old Standby?
Well... get back non-believers or the rain will never come. Here's the reason, the original Old Standby was vented. That's right, it's been under your nose all these years. I have never heard a single person say the Old Standby has side vents. If you have one, look at it from the side. They are there, right in the top corners. The Marine Band has these small top vents as well, but they aren't as pronounced and most of the side air goes through the big vent

Last Edited by on Oct 12, 2012 4:39 PM
ElkRiverHarmonicas
1332 posts
Oct 12, 2012
4:40 PM
Dang just noticed two of those posts got automatically cut for length. Who knows what gems went unsaid. I probably rambled enough on this anyway. ;)

One thing I remember typing that got cut was response to Adam Hamil's remark that some people think they are louder. I think they are, slightly. I don't think it's because sound is coming out closer to your ear, I think it is because of increased air flow. I might test that someday.

I don't know if typed anything above to the contrary. I was just thinking about when I figured out it was air and not sound going through those side vents and had kind of forgotten earlier about when I discovered it.
I had come to the conclusion before I worked at HH that the side vents had nothing to do with transmission of sound. But I had no idea what it was. I was in Chicago, the very heart of Yankeedom, and was discussing this mystery with Brad. He says, "your problem is, you're not thinking about air."
I stood silent for a while and the puzzle pieces all started coming together all these wheels started turning and I was very excited. Once the concept started rolling in my head and I had a grasp of it, I asked a million questions, and he answered them and showed me things his findings on the subject.
That was one thing I really loved about Brad. If you were trying to grasp a concept, he wouldn't cram a lot of information down your throat. He would spend the time - and it took far more time than just telling you - to help you make discoveries. That was so exciting.
You'd say "I'm having trouble understanding how side vents work" and he wouldn't ramble on with all this info like I just did. He would say something like "you're not thinking about air," he would literally stand by in silence and wait for your questions. let you have that excitement of discovering it on your own." It was totally typical of him. When I say it was the best job I ever had, it was for reasons like that.
If you worked for him and you had a thirst for knowledge and a hunger for making yourself a better person, he was an incredible man to work for. If you were working for him and had none of those things, you'd probably think he was a horse's ass, because he was constantly trying to instill those things in his people.

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David

____________________
At the time of his birth, it was widely accepted that no one man could play that much music so well or raise that much hell. He proved them all wrong.
R.I.P. H. Cecil Payne

Last Edited by on Oct 12, 2012 5:10 PM
boris_plotnikov
789 posts
Oct 13, 2012
6:16 AM
Thanks for info, David!
I like side vents only for diversity and usually use them on a less used (spare) harps. I have small hands and cupping is not easy for me.
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HarpNinja
2766 posts
Oct 15, 2012
10:29 AM
I GREATLY prefer side vents in all keys. Open backs, maybe not, but for sure side vents!

I downloaded some iPad stuff to show the differences in numbers, but have had little time to work on sharing this. I'll do my best to actually show the differences this week. The problem was I had a very specific method I wanted to do, but didn't have all the right stuff, ie, OOTB harps.

I think I can do several experiments on several brands in the key of A and D now. We'll see. The plan is to simply play a 4 draw and a 4 blow on each harp stock, then with various covers. The app I have should let me snap a pic of the EQ and dB of each note.

My hypothesis is that the covers, regardless of harmonica, will change both the EQ and dB of the instrument. If I had time, which I really don't, I'd do this both acoustic and amped. For now, acoustic with the iPad mic will have to suffice.

I can see there being an issue with every note not being in the extact tuning from harp to harp...I'd rather not have to tear apart 2-4 harps and retune, but I suppose that might be an issue??????
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Mike
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Willspear
204 posts
Oct 15, 2012
11:51 AM
Side vents i feel are fairly important. Massive sonic difference always on tap with change of cup.


I must be the minority in feeling too much emphasis is put on bass all the time. Heck with vents I can still cup so tight that extra reeds sound.

Vents give the ability to brighten sound in a big way easily without relaxing the seal around the mic. The change is much more than relaxing the covering of holes in the upper octave when not used.

I feel too many people are afraid of mids/treble and presence. Which are all essential to get cut in a mix.

Last Edited by on Oct 15, 2012 11:54 AM
ElkRiverHarmonicas
1342 posts
Oct 15, 2012
12:31 PM
Pretty much all that extra tone from the side vents is treble. If you can't pick out the actual tone that's added, play a note and then cover the vent. The pitch will sound like it actually gets flatter.

I think probably the most true side vent test you could would be to play a draw note on a B-radical with the drawplate isolated ventwise (the blow and draw vents are connected. Then cover and uncover it. I have to do that someday.

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David

____________________
At the time of his birth, it was widely accepted that no one man could play that much music so well or raise that much hell. He proved them all wrong.
R.I.P. H. Cecil Payne

Last Edited by on Oct 15, 2012 12:33 PM
isaacullah
2158 posts
Oct 15, 2012
12:44 PM
@Dave: I just tried the vent-covering/uncovering thing with some marine bands, including my pre-war G harp. I dunno... I can't tell if I really hear something or if it's my mind pulling tricks on me... Is it a tonal change? A volume change? Am I changing my embouchure when I move my finger to cover the vent? I can't tell! I need someone to do a double blind recording and post it here so I can listen to it... We need science! :)
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ElkRiverHarmonicas
1344 posts
Oct 15, 2012
12:57 PM
GOnna make a new thread. One thing I learned at the SPAH 2010 comb test was that the player is probably the last person who can hear stuff. This test I posted in the new thread will be probably be very helpful.

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David

____________________
At the time of his birth, it was widely accepted that no one man could play that much music so well or raise that much hell. He proved them all wrong.
R.I.P. H. Cecil Payne

Last Edited by on Oct 15, 2012 1:09 PM
walterharp
958 posts
Oct 15, 2012
2:49 PM
yeah, need a harmonica blowing machine to make the note the same way and blind listeners.

also curious if using the thumb to block the vents does not damp the cover plate vibrations any.. so something light that covers it would be better than mashing a thumb against it
ElkRiverHarmonicas
1348 posts
Oct 15, 2012
5:38 PM
Surprised it took somebody that long to mention that. Pick up a harp and try it.

But I wasn't mashing. Just blocking.


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David

____________________
At the time of his birth, it was widely accepted that no one man could play that much music so well or raise that much hell. He proved them all wrong.
R.I.P. H. Cecil Payne

HarpNinja
2770 posts
Oct 16, 2012
5:38 AM
Yesterday I took snapshots of an "A" Marine Band, stock, with different covers in Sound View. The issue was I had to use two hands to take the snapshot, and although I came up with a solid approach for doing this, I didn't feel it was very scientific.

I was going to share the pics anyways, but they are PNG files or something and I can't upload to flickr and must have to convert them or something.

At any rate, you can visually see the differences between covers, for sure. I used a 512 band eq for the pics. I used the following covers, stock, Crossover, Special 20, and opened Special 20.

Tonight I will go ahead and record the playing with different covers into Audacity and then playback through studio monitors. I'll take pics during playback instead and see if I can upload the audio and pics to Youtube or something. I am not good with this stuff.
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Mike
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Horwellston
8 posts
Feb 10, 2019
2:01 AM
I'm a cupping guy.

On harps with no vents I'm always activating the other reeds miles on the harp from where I'm playing because my cup is so tight and the air is has nowhere else to go.
With marine bands and their vents I never have this trouble.
nacoran
10059 posts
Feb 10, 2019
12:49 PM
Horwellston, that's actually a technique! I use it sometimes to get a 10 blow with a 1 draw. :)

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Nate
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