DRE and PS Engineering
My number 1 and 2 choices would be a DRE 244e, than the PS Engineering PM1000 (now PM1200) or PM3000 (stereo).
DRE went out of business recently, but you should be able to find a new 244e still in stock. I would not hesitate to buy one today. Don't know why DRE went under; they where best rated by Aviation Consumer. They where a small family business. I bought mine at Oshkosh, so I met the principles. They made a top quality product and probably made min profit. That's too bad, it's a great product. Also top of the line is PS Engineering. PS Engineering has been around for a while. I have owned both DRE and PS-Eng. They are pretty close. However if the out of production thing bothers you about DRE, than the PS-Eng is first choice IMHO.
You get what you pay for, especially with an intercom. Some intercoms are very cheap and do it by cutting corners. Yes they are VOX (voice activated) but they have one VOX control. What that means is when you the pilot speaks, BOTH mics open and let more background noise in. Same with the passenger, they speak, both mics open. Also the filters and amplifiers give the sound quality or lack thereof.
You can tell the DRE or PS Engineering and other high end units have separate VOX circuits, because they have individual volume and squelch controls for each the pilot and the passenger.
Stereo? If you are going for stereo you want a stereo intercom, one that has left and right channels for stereo aux music input and stereo headsets. The lower priced so called "stereo" intercoms sometimes are really mono inside. The top line units also have more power and better music intercom control, such as how the the music fades back in very gradually after time when the radio or crew communications stops. I think a true stereo intercom is a must for music, but if you're on a budget, not picky and not going to buy stereo headsets, you can save cash with mono unit. Also there are more wires for a stereo intercom. If you are not going to use it than mono is fine.
I have used the DRE, PS-Eng, Sigtronics and Flightcom. The old Sigtronic's I used where very basic panel units we had in rental planes I gave flight instruction in. They worked is all I can say, nothing special, but that was a long time ago. The Flightcom was a portable unit I had in my RV-4. It was pretty mediocre and got rid of it for a panel mounted PM3000. No comparison. Also the nice thing about the PS Engineering was you set the squelch and forgot it. Never used a Softcomm or Flighttech. Never heard of Flighttech? Again you get what you pay for.
I don't care about "voice recorders" ATC read back features or cell phone inputs. Some headsets have those features built-in if they turn you on.
You may like a $150 intercom, but you will love a $450 intercom. I am all for budgets, but the intercom is such a basic thing you use all the time, I think going top shelf is money well spent. However if you don't fly with passengers much or music, than who cares, you don't even need an intercom.
One brand top brand is NAT - Northern Airborne Technology Ltd.; NAT makes top of the line TSO'ed commercial communication units, you might find in EMS or sightseeing helicopters or corporate turboprop aircraft for example. The
AA80 is their general aviation unit. The
AA83/82 is the stereo one. Sometimes you see the mono ones on eBay. If I saw a stereo NAT for sale I'd buy it. Not sure they these units are still in current production.
Dave Clark's top of the line intercom looks good. Never used one, but they show up on eBay sometimes. They have high quality specs. However looking good is not the same as sounding good. They also make a low cost unit that is on par with the ones you mentioned.
The above is my opinion and does not reflect the opinion of management.
The best thing to do is go try them in a plane, which is easier said than done. You have to hear the quality of sound. The "secret technology" of an intercom is how it keeps from clipping voice at the ends, sound quality and ability to pass voice with out passing the noise. They are not all the same. Some are rich and some are tinny. You can't go wrong with the ones I mentioned. Considering DRE is not in production and NAT is kind of rare or the models I mentioned out of production, PS-Engineering would be my first choice for a new unit (1000/1200/3000).
PS-Engineering does makes an entry level unit, the PM501. That would be a great intercom if you are on a budget.