RC Sound systems?

[SIMON CRAGG]

I am a total sprog when it comes to rc model sound systems. Thinking about getting a Merlin sound system for my soon to arrive Flightline Spitfire. Ideally, I dont want to shell out to many Stella coupons, just want something basic that will do the job. Any experts out there that can point me in the right diection please?. Thx Simon.

[Denis Watkins]

Some reading if no one comes back Simon

**LINK**

[Biggles' Elder Brother - Moderator]

If you buy a conventional cheap system based around loudspeakers it will not work well in a foam aeroplane, you would be wasting your money in my view.

The MrRC system works fundementally differently from a loudspeaker based system. I have explained this here in my post on 21/09/18 at 11:13:15. And works quite well in foam models in my experience.

BEB

[Allan Bennett]

As BEB has said, transducers are probably best for foamy models, partly because they don't require you to cut out a speaker aperture or to then cover it with some kind of grille. It seems to me that, for best effect in a foamy model, transducers should be attached to rigid panels -- e.g. fibreglass or liteply -- glued to the foam so that they can transmit their vibrations more effectively.

Provided you get the impedence right, transducers can be substituted for speakers in any sound system. I use them with my Benedini system in one model, and speakers in another.

[Phil 9]

one of these makes a great sound

[Biggles' Elder Brother - Moderator]

Yaaaaawwwwwwnnnnnn!

[cymaz]

Phil might be on to something....I’m not going to go into the electric/ic debate. It’s pointless, every pilot has his own engine preferences wether by choice or club restrictions.

We had a member with an electric hurricane and a sound system, it was great on the ground and in the pits bit in the air it was poor.

If you want an engine sound look at the possibilities of buying an engine...why have a dog and then bark yourself.

Edited By cymaz on 02/10/2018 22:37:47

[Biggles' Elder Brother - Moderator]

I very much doubt he's "on to something", you see the thread this stems out of concerns a foam model that Simon is thinking of buying!
Besides which, whatever makes you guys think a twin cylinder Harvey look-a-like sounds more like V12 than a digital recording of a V12 eludes me!
BEB

[Martin Harris - Moderator]

Posted by Biggles' Elder Brother - Moderator on 02/10/2018 23:39:03:

a twin cylinder Harvey look-a-like

Looks nothing like a 6' 3 1/2" imaginary white rabbit to me!

...although maybe there's something about the ears?

 

Edited By Martin Harris on 02/10/2018 23:58:26

[Biggles' Elder Brother - Moderator]

Grrrrrrrr! Spool chucker.
OK chaps, fun over. Let's bring this back on topic please. The topic is that the OP would like advice on sound systems, so if you have first hand knowledge of such please feel free to contribute. If not then allow the thread to run without spurious and irrelevant comment. Thank you
BEB

[Tim A]

I have an ESS Sense Hobby RC sound system I brought from RC Castle a couple of years ago. Finally got around to installing it in a VQ Dauntless 46 size. Good sound with transducers and an easy install except I haven't been able to get it to enter calibration mode. By connecting it to a separate channel and setting the low end point the sound now starts just a fraction after motor start, but (there is always a but somewhere) on shut down the sound continues for 20? seconds or so after the prop stops.

Does anyone have experience of this and is there a solution?

By the way these are much cheaper from RC Castle $79.99 than Banggood $180.00?

[YakMad]

I have used the ESS Sense sound system in several models, it sounds ok on the ground but is lost in the air, the sound level is just to low, I even tried it in a twin foam model, the sound level was still too low to hear any proper sounds when the model is flying, the supplied transducers are just too small, I have also had problems calibrating it. I think you would really need to spend a lot more money on a decent sound system if you are serious about getting the proper effect, mine now resides on the bench.

[Biggles' Elder Brother - Moderator]

I have a solution to this that works well Kiwi, but whether you can use it or not will depend on what Tx you are using! I use FrSky (either Taranis or Horus) both running OpenTx. OpenTx means you can eat problems like this for breakfast!

OK, here is what I do. Firstly I create 3 curves that I will use as substitute throttle curves dedicated to the sound system - I'm using MrRC but the principle of this should would with any sound system I guess. The motor runs entirely off the system throttle curve, these new curved don't go near that they just feed the sound system. I can select which curve is the one being inputted to the sound system via a 3-way switch on the Tx.

The first curve is purely for start up. No matter what I do with the throttle stick, the lower 50% of the curve is a very low portion followed by a slow upward ramp to 50%, After which it behaves "normally"

The second is a general flying curve. This is a straight 45 degree line except for the first 10% or so. You see I have the opposite problem to you in that the system goes into shutdown sounds immediately when you reach throttle zero. Now you might think that's fine, but the problem is when I do, say, a loop or a stall turn and cut the throttle at the top I get all the "popping and banging" of engine shut down (a scary moment for my pilot) only to then have the system go into "start up" sounds when I repoen it! Annoying and not very realistic. So this 2nd trottle curve basically never lets the system see "zero throttle" the last 10% of throttle movement is just a horizontal line at 10% sound level - a sort of simulated tick over. Again note that this curve only drives the sound sim, it doesn't control the actual motor which will stop and freewheel.

Finally curve three is a bit of a "spare" for me. I put it in the programming because a) I have three positions on the switch and b) its in the programming infra structure, so if I do come up with a pressing need for it I have it ready "off the shelf" as it were. At present I have looked at using it for shut down effects but haven't reeally done a lot with it. I could, if I had your issue put a timer on it that would ramp down then switch the curve to negative on competion - that should stop it!

Right sorry if this is not a directly implementable solution for you - if not maybe you should think about going OpenTx But even if it isn't it may give you some ideas I hope.

BEB

[Tim A]

Thanks for the prompt replies Guys.

BEB, Thanks for explaining your setup, I am a Hitec user so OpenTx isn't an option but you have given me an idea or two so will have a play and see what might work on my A9. If I can't I will just use it as is. Have thought about going down the Taranis route but the thought of replacing 20 odd Hitec receivers is a wee bit daunting!

As I said in my previous post I already have the sound system on a separate channel but found tonight that if the low end EPA on this channel doesn't match the throttle channel the motor will start when throttle lock is on for safety??

Something else to get my head around, I don't give up on a challenge easily either!

Kiwikanfli.

[Tim A]

Just an update for anyone who is interested. Took BEB's advice and programmed sound to work on a fuel mixture channel (A fuel mix on a Leccy is this a first Haha?).

Got the start to work fairly well prop starts before sound, but got no where with the shutdown in spite of changing the settings. Eventually came to the conclusion that it wouldn't matter what I did it won't help. The control module only goes into shutdown sequence when it sees the throttle at zero.

Obviously shutdown is solely controlled by the module after closing throttle, it then runs until shutdown sequence is finished.

At least is it more realistic than before thanks BEB.