AAIIR - Acousticoils

[jmerring]

Have any of had any experience with these slide inserts that increase resistance; assumably to make the horn play more easily and in tune?

http://WWW.DMAMUSIC.ORG/ACOUSTICOILS/" target="_blank (cut and paste the url, please, if neccessary)

I am considering trying one, to help me with 4th valve C and F (2 & 4 ledger lines below).

Thanks for any opinions.

[tbn.al]

Come on, guys! Mr. P himself endorses this thing. At least his name appears in front of an endoresment.

[imperialbari]

As they are advertised these devices appear to work perfectly as contributors to the pension fund of an elderly gentleman. And as the price after all isn’t higher, nobody notifies the police about this thinly veiled charity scam.

However something similar has worked in the real world of brass instruments.. Just about all modern professional level French horns come with valve slides needing a permanent pull for proper pitch. One certain wrap named after the maker introducing it in America, Carl Geyer, is notorious for not having the written high Bb (concert Eb) speaking at all on the Bb side of the double horn. Very impractical in solo work and in high orchestral passages.

There has been much speculation why only this model/wrap was affected. Some found out that an important node (or maybe rather a bug) was located in the 1st valve at exactly the stretch, where the bore was increased due to the slide pull. One repairman found some tubing identical to that of the male slide branches. He cut off two lengths equivalent to the slide pull and placed these pieces of tubing inside the female slide branches for an overall uniform bore of the first slide. The high Bb/Eb popped out of the Bb side of that horn and everybody involved were happy.

K

[jmerring]

Guys (and gals, as appropriate; not one of you actually answered my question. I really would like to improve the notes. They play VERY sharp, even with the 4th slide almost dangling from the horn and the main slide out two inches. Please, if you don't have an answer to my question, don't post anything. Thank you.

[Casey Tucker]

i actually purchased one of the theses not to far back and have tried it only on the main tuning slide in both my F and CC. i found that when placed in the F there wasn't a noticeable difference but when inserted into my CC i notice a lot (more good than bad). as far as tuning goes i haven't noticed much of anything; my tuning has stayed the same. (which is OK with me ) the sound has also stayed the same, but that's an opinion of course. (i recorded myself before i bought it and about 3 days ago) i have noticed an increase in pressure which i like but am a little worried about. i now can start at a lower volume with a clear articulation and response but at the same time i often wonder if a) i'm now depending on the device, or b) it was all in my head and some extra time practicing would do the same thing. at the moment i'm starting to ween myself off of the acousticoil and that you could probably get the same or better results by spending the time it takes in a practice room. oh, and practicing is always WAY cheaper. my $.02.

-CT

[james]

I've been given two of these for free and both sit in my storage closet. Only a change of slide-length or a change of buzz will result in a change of intonation. Want a better solution? Buy a $20 Korg tuner and the "Tuning CD".

Edit: If intonation is the concern, then this gimick item won't help you: Only a change of slide-length or a change of buzz will result in a change of intonation.

-james

[imperialbari]

Guys (and gals, as appropriate; not one of you actually answered my question. I really would like to improve the notes. They play VERY sharp, even with the 4th slide almost dangling from the horn and the main slide out two inches. Please, if you don't have an answer to my question, don't post anything. Thank you.

You don’t own no thread, especially when you didn’t tell anything relevant about your situation until your second posting. You didn’t tell the pitch of your instrument, but now it is possible to deduce that you play a 4 valve BBb tuba. Your combined length of main bugle and 4th valve tubing cannot bring the pitch down sufficiently even if main and 4th slides are pulled.

You very likely can forget about acousticoil. The problem rather is, that you have one of the rare instruments where the 4th valve doesn’t lower the main bugle a fourth but a major third.

Tells us the brand and model and post photos displaying all of the 4th valve wrap for comparison with the main bugle.

It isn’t advisable for a person unable to pose a question properly to lay down the rules for those who can provide the answers.

This posting was unduely kind towards you, so go behave.

K

[jmerring]

I thank you for the responses; I really did not mean to be nasty. Imperialbari - you are a fountain of knowledge and I thank you for your reprimand. I play a Miraphone 186 BBb (1 year old). I assume that you and almost all the other posters on this board are familiar with the horn. I did not know about the fourth valve dropping closer to a third, than a fourth. That is one of the problems, I guess. My practice time is another issue, entirely and I know I don't put enough in. Lastly, I finally have a definitive opinion from one of you ... I won't waste my money.

Many thanks,

Jim

[jmerring]

No nastiness at all! This is funny stuff. We were all just dancing around the answer, thinking how clever we were and falling on our collective faces. So we then just laid it out there for you. I certainly hope that you did not think that any of OUR feathers had been ruffled!

I really DID think I had ruffled feathers. I will develop a thicker skin (that will be on my list of evolutionary processes over the next 10 or 12 thousand years).

Bloke, thanks for the info about your band's solution. It would seem to be very logical. My fourth slide pulls about 5 inches, and I am STILL badly sharp (unless I just blow the hell out of the note; you know, FF even if the part is written pp). Now to find a GREAT repairman in South Florida ... the best ones are up north of here at least 600 miles.

[imperialbari]

It stands that the given combination of instrument and player comes out sharp on the two most common notes fingered 4 on a BBb tuba. bloke has come up with one potential reason for the problem, even if I wonder why Miraphone would fail on its old reputation of building maybe less than exiting instruments, but very reliable instruments.

A cross check may be done to see if this tuba has been intruded a hat, a toy, or another physical entity.

If the valves are set up correctly by the maker, the said C and F shall sound slightly sharper when fingered 1+3 versus fingered 4. If these notes also sound extremely sharp when fingered 1+3, then an obstruction of the main bore would be very likely.

It might be worth hosing out the main bugle and if there are no obstructions there, also the valve tubing. While I had a bathtub I covered the bottom with a large towel and placed the tuba there with the leadpipe pointing upwards. I took the handle off the shower hose and put the hose to the leadpipe, so that the bore was flushed with warm water. Make sure you have a firm grip on the hose. Also make sure all slides are pushed all the way in. If the water pressure is too high the slides may pop out when the valves are activated.

My new home has no bathtub, so there I put the towel on the bathroom floor and then carry out the same procedure.

K

[jmerring]

Unless someone has been playing my horn, while I wasn't looking; there is no obstruction in it. I am it's first owner and it is my 'child.' I have tried reversing the 4th valve (left to right) and that helped a little bit. My knowledge of the inner workings of rotary valves is limited (at best), but I am going to ask my local repairman if the 4th is aligned correctly, because I have been noodling around with the back cap to increase valve speed (it slows to a crawl if the cap is too tight - which I am sure all of you know). Thank you again, friends. BTW, if there is a simple way for me to check valve alignment; could someone fill me in (pictures, please ... no big words ...OG stupid!).

[iiipopes]

On all rotary valve horns, including especially Miraphone, when you unscrew the bottom rotor cap (the one you have been adjusting) you should see two notches filed into the rotor casing to indicate alignment, and one notch on the rotor that should line up with each casing notch in closed and open positions respectively. If they don't line up, and it's something more than a straightforward replacement of bumpers will fix, then, and everybody sing along to the tune of the William Tell Overture:

To the tech, to the tech, to the tech, tech, tech!

[jmerring]

Wow; thanks for the information, guys! I will look VERY closly at my caps and alignment marks (magnifying glass). I hope this helps. I probably screwed it up to start! Again; OG STUPID!!

[Roger Lewis]

Another thing to check are the ferrules on the main tuning slide. I have seen a number of horns that came over with European slides (where the pitch is A=443 or so). If the main tuning slide ferrules are about 3/4 of an inch long and not closer to 2 inches, then you most likely have Euro slide on it and have been successfully lipping a lot of stuff down, but it just doesn't work on the 4th valve. The change in main slide would add about two inches or so to the whole horn and it should make everything more stable.

Just a whacky, fleeting thought.

Roger

[tubaguy9]

Another thing to check are the ferrules on the main tuning slide. I have seen a number of horns that came over with European slides (where the pitch is A=443 or so). If the main tuning slide ferrules are about 3/4 of an inch long and not closer to 2 inches, then you most likely have Euro slide on it and have been successfully lipping a lot of stuff down, but it just doesn't work on the 4th valve. The change in main slide would add about two inches or so to the whole horn and it should make everything more stable.

Just a whacky, fleeting thought.

Roger

That's actually exactly right. I had a band director that had the exact same type horn you (jmerring) had, and it was always pulled waaay out, and he talked to someone from Miraphone at a convention, and got an American tuning slide at no cost to him. So you might ought to consider that...

[MaryAnn]

Getting back to the acousticoil: If you want to check for yourself what it does and does not do, just cut yourself a strip of plastic from a thin plastic bottle, and start inserting it (coiled) where you feel like in your tubing. That should show you exactly the results. The acousticoil is a pretty thin piece of plastic, so a thicker piece from a bottle should get you "even more results" than the true article.

MA

[jmerring]

Greg, you're a riot!

My understanding that increased resistance = smaller bore. That having been said; I checked the alignment on the 4th rotor (took the back cap off) and it is (visually) right on. There is an infinetesimally small mark on the rim of the back cap, that I assumed should also be in approximate alignment with a corresponding mark on the exterior of the rotor body. I was not able to find any such mark (a strong magnifying glass was used), so I made my best guess and just put the back cap on, finger tight. I do not have a screwdriver small enough to actually tighten the cap/rotor, but the action is quite fast and the intonation has not changed. I will take it to a tech ASAP, to do it right.
The ferrule on my main slide is 2 inches long, I must make the other assumption that it has the correct length of tubing. The darn thing just will NOT come down in pitch on the aforementioned notes. I suppose that if I had a slide kicker on the main slide, I could force the horn down for those pitches (whenever it would make any difference, i.e., a note played for more than a beat at say, mm=60). Any faster, and those notes are not noticable to our primary audiences.

Whew! Thank you, everybody.

[imperialbari]

bloke’s assumption of a too short 4th loop/slide becomes more and more likely.

Do you know how to check slide lengths against open notes? Not that this method is any more exact than the combination of the tuba’s being in tune with itself and of your playing skills.

The length of the 4th slide may be checked by playing F at the bottom of the staff open against the same note fingered 4. If the latter version is sharp, then pull the 4th slide until that F is the same on both fingerings.

I have met very odd tuning patterns in some low end instruments, but I tend to refuse to believe that the low C and the low F are sharp with just about the same amount without the reason being traceable to the length of the 4th valve loop.

K