Note 17 - Segment Information - Segment Disclosures (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2018
Revenues	$ 8,863,726	$ 7,514,068	$ 29,232,976	$ 23,011,082
Operating Income	686,461	(178,127)	3,411,722	1,417,132
Depreciation and amortization	225,681	143,469	623,317	337,200
Interest expense		4,388		14,205
Income Tax Expense (Benefit), Total	118,310	(73,749)	675,457	2,793,590
Long-lived assets	6,051,148		6,051,148		$ 6,452,061
Total assets	42,015,775		42,015,775		41,860,797
Intersegment Eliminations [Member]
Revenues	257,302	96,192	724,271	186,010
LRAD Segment [Member]
Revenues	8,302,811	7,012,430	27,606,026	22,094,790
Operating Income	660,106	(63,257)	3,245,060	1,507,264
Depreciation and amortization	149,331	62,665	392,296	187,433
Interest expense
Income Tax Expense (Benefit), Total	118,310	(73,749)	675,457	2,793,590
Long-lived assets	2,381,722		2,381,722		2,478,144
Total assets	37,029,052		37,029,052		36,770,872
LRAD Segment [Member] | Intersegment Eliminations [Member]
Revenues
Genasys Segment [Member]
Revenues	560,915	501,638	1,626,950	916,292
Operating Income	26,355	(114,870)	166,662	(90,132)
Depreciation and amortization	76,350	80,804	231,021	149,767
Interest expense		4,388		14,205
Income Tax Expense (Benefit), Total
Long-lived assets	3,669,426		3,669,426		3,973,917
Total assets	4,986,723		4,986,723		$ 5,089,925
Genasys Segment [Member] | Intersegment Eliminations [Member]
Revenues	$ 257,302	$ 96,192	$ 724,271	$ 186,010