LED works but labview speaker does not oscillate.

[ankyxia06]

1, This circuit oscillates with LED (in multisim 14).

2,This circuit does not oscillate with speaker (labview, in simulation it only beeps twice and becomes silent, playback time 10 s, sample frequence 220 Hz), then changed on R1 from 47k to 10000k and C1 from 1 nF to 100 uF, it does not oscillate at all with all attempts. Any suggestion on changing some parameter to make this work?

[tipa]

Это косяк самой программы. Посмотрим, что скажут создатели MS. Скорее всего промолчат, как всегда.
Я пытался неоднократно запускать звуковые файлы в программе, получал то же самое,- короткие "дзинькалки", а дальше-молчок...
Файл в формате "ms" скиньте пожалуйста.

[ankyxia06]

thanks, I googled your answer in Russian for translation. 

could it be possible that you can pull some MS master for this issue?

please type in English as I am a totally stranger to Russian. 

[tipa]

Good. Put the browser 'Yandex', there is a wonderful translator, especially technical texts. 
There is no ground on your oscilloscope
Manifold (collector ) Q2 in the air

[tipa]

I simulated your circuit. It is unstable and gives large impulse surges. Found this one on the internet. It works better, although it is also not perfect.  Although the frequency is adjustable

[tipa · Accepted solution]

Your transistors have large spikes.

Внизу справа время симуляции, но звуковой файл всё равно короткий получается.

[ankyxia06]

hi Tipa, it inspired me. now it works if I only wire speaker between load resistor(or LED) and Q2 collector, speaker works. thanks. 

For the grounding issue. 

Once I learned that labview speaker only has one lead and the other one is by default grounded, that's why I DID not ground the Q2 as it is grounded via speaker.   it is from one of the netusers. today I checked with Ni homepage as below (photo 1 below). it looks like you are right that the it is not grounded, correct me if wrong. 

if it is by default grounded on the other lead, then my 2nd circuit is grounded with Q2, so today I tried put different resistance load under Q2 collector to ground, it also ocillates (with 1ohm to like 1000ohm), but it does not oscillate with 3000ohm so I guess it would be related to resistance/impedance. so when I put back speaker to replace the load resistor, it did not oscillate. So I guess the speaker has a high or very large impedance. 

simply sharing my logics and free to tell if some of the intepretation is wrong. 

snapshot from Ni multisim

[tipa]

Thanks for the info. I think it will come in handy someday.

У него нет ёмкости и очень большое сопротивление, так что через него коллектор подключать неправильно.