it would be a better design if the output and input 5 weren't on ...
921455
I originally purchased a RocketFish brand HDMI switch from one of the big box stores for $70 and it didn't work at all. Only one channel would play anything and none of the others would consistently work. Needless to say I returned the RocketFish HDMI switch and purchased this Kinivo HDMI switch. So far this thing is working 100% perfectly with the 3 inputs that I have connected. I have not tried plugging anything into input 4 or input 5 yet, so keep that in mind. As others have mentioned, it would be a better design if the output and input 5 weren't on the sides of the unit.
733931
Good design and decent sound for the price. However, 2 things irritate me about this:
1. It makes an annoying and loud sound everytime it turns on and everytime it goes off after a standby time. When I'm trying to sleep to some music, this sound wakes me up again. This is why I stopped using it for this purpose).
2. There's no button bring it from a standby or off mode. You have to fumble with the back switch and turn it off and on again to turn on the speaker again. This is a bit annoying. The back on-off switch is a bit too stiff for my liking.
3022256
It has been quite useful, but this may be a feature of almost any external storage drive, but the fact of its not having a means of turning on/off without unplugging is a major nuisance.  This is especially the case because it makes a noise when left on, even when it's asleep.  Even worse, it didn't play well with Time Machine in a few instances involving the computer going to sleep, and I had to do a couple full backups from scratch.  Maybe you can blame Apple to some extent, but I wish I could trust the device more to the point of being able to leave it plugged in, rather than backing up periodically.
1993583
The unit does not work, and if I had four monitors (instead of two) that I wanted to plug into it, there would not be sufficient clearance.
4009353
The bad: 1. Displays output voltage by default (which should be assumed to be properly regulated by the inverter wouldn't you think?) and the display only indicates the other options for like two seconds after a button push. That's hardly enough time to even capture the reading. kVA would be a better default display or Input voltage as most users would want to monitor their battery condition and /or battery loading. Selectable would be ideal. 2. The battery terminal nuts have plastic encased knobs that make it impossible to achieve tight cable lug connections. I had to purchase some quality metric nuts which did tighten well to the connection studs. 3. This damn thing draws over an amp from the batteries with no load connected. I believe that means it has a low power factor, but what it ultimately means for us end users is that it will eat up your battery (or batteries) if you leave it powered on even with no load. I have my inverter in my shed connected to a 115ahr deep cycle battery charged by a small solar panel through a charge controller. Works great, but when I turn it on to play something low power (like my radio), it drains it. Then if I plug in something that uses real power (like a saw or vacuum) I have less run time because of the wasted power. RIDICULOUS!!!

The good: 1. It seems to have clean stable power. 2. The soft start is a nice feature 3. Solidly built with the exception of the plastic battery terminal knob nuts. 4. The remote is really a nice feature, and it doesn't seem to draw much power if any when powered off by the remote, although I have not measured it yet.

Bottom line, it's a well made, heavy, good inverter, but too wasteful! Find one that is more efficient under no load or low load conditions unless you only plan to use it fully loaded. I suspect that the power factor is better when loaded (closer to 1).
2129102
I like it, if you use a better power supply it works well. I would buy more.

the big down fall is the crossover is a joke, and the sub control is completely independent of the master volume.
226242
OMG, programming this thing is like setting the combination to a safe.  And it loses it's memory and needs to be reset every time there's a power interruption.  I'll pay the extra price for a switch with a little keypad and a battery backup.
3489584
only 5v input and the software is pretty terrible.  For the money its a powerful tool though. I'd buy another one if this one broke.
1199039
This would be a five star review but I need a PWM controller that switches positive (+).  This one switches negative and for my purpose that makes it unusable without additional effort.  This may not be an issue for you if you do not need to bridge supply - and output -.  Item description does not make this information available.  I was hoping that it would switch at a frequency outside the range of human hearing as I would be using it in close proximity to audio gear.  It does: 250kHz.
1694315
I really like this beautiful and visually striking receiver with plenty of clean audio power output, but it could have been built with tape monitor(s) for patching external devices.  A digital readout for the FM/AM tuner, which is non-existent.  Furthermore, the function keys are not backlit and cannot be read in the dark.  I personally could do without the demo mode, which turns on at random when the selected function source signals are not strong enough to drive the display (Hence the function selected); then the display gives you an unwanted demo light show...annoying!  All-in-All you cannot beat it for the price!
3535849
Note, when this unit works, it actually sounds good. However, it gets one star due to the fact that the "Auto on/off" switch doesn't appear to work as expected. The switch has 3 positions (normal, auto, and trigger). When set to Auto, it is supposed to switch on or off automatically when sound is detected. I have found that the level of sound required is much too loud. Also, it turns off way too quickly, after only a brief period of silence or low sound levels. Therefore, when playing video games the unit constantly shuts off and turns back on several times.

So, I tried to use the "Normal" setting, which is SUPPOSED to disable the "auto switching" and make the power turn on and off by manually pressing the power button. Well, with my unit, the power still automatically turns off when there is no sound detected no matter what position the switch is in (auto, normal or trigger). I have ordered a replacement unit from Amazon, but the quality control appears to be lacking for this company.
4825705
First off, I'd like to say that this receiver is generally well thought out and IF it keeps working for you, then you will likely be pleased with the general sound fields, receiver appearance and operational layout with the following limitations. (the one star is for poor operational quality)

1. If you want to export any of the digital music information out of the receiver to either a zone 2 (like I have in RCA format)or even another digital device in say another room, you are SOL with this receiver.  If you attempt to turn on the HDMI audio out to the TV monitor you're using (in hopes of using it as a digital audio line out), the receiver is designed to shut off ALL speaker output to the room in which it resides, thereby leaving you only with your TV speakers in operation. (apparently some people find this desireable).  The Yamaha RX-V471&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Yamaha-RX-V471BL-5-1-Channel-AV-Receiver/dp/B004QR56R0/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Yamaha RX-V471BL 5.1-Channel AV Receiver</a>&nbsp;I bought as a replacement simply allows one to turn on the digital audio output to the monitor while leaving the receiver speaker sound unaffected, thereby allowing one to buy a audio extraction device&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/HDMI-Audio-Extractor-Digital-to-Analog-Converter-Dolby-Decoder-Optical-Stereo-RCA/dp/B005COKXCO/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">HDMI Audio Extractor Digital to Analog Converter Dolby Decoder Optical / Stereo RCA</a>&nbsp;which allows one to send that data then to another zone.  BTW, for all you "zone 2 line out" hopefuls like myself, NO, that line out is ONLY for inputted ANALOG information and NOT digital down converted analog information.

(note to Onkyo designers......hey guys, how about offering a digital "line out" like you have for the analog section, or maybe even a down converted analog line out?)

2.  The input "naming" capability is very weak as compared to the Yamaha RX-471 as is the on screen programming guide.

3.  What, no "spare" HDMI input jack on the front of the receiver for plugging in computers and what not? (This goes for most all receivers I've seen, even my new Yamaha.)  I mean, come on, couldn't we at least wire up one of the available HDMI ports in parallel with such a front jack?

So, having said the above, I would imagine most users of the Onkyo 509 are generally happy with their purchase (assuming their HDMI jacks don't start failing like mine did virtually right out of the box) given they aren't looking to port all that internet and i-phone music to another room.  The auto room setup was really nice, and generally the receiver all around is well done.  The poor quality control (or is it just a poor HDMI port design?) is a crying shame for a product that might otherwise have been a home run for Onkyo, even with the limitations I have listed above.  Hopefully you've had better luck with your purchase of this receiver than did I myself.
2025694
It could do better if it is just a little less sensitive, meaning it turns on the light too soon.
4767703
The power input port or the plug itself is too small, so it disconnects unless you shim an piece of paper or other item to retain the power connection.
665814
I have to unplug one of the cables when I use one of the inputs, otherwise I get buzz.
42330
I had to return it as 5 of the ports didn't work.
4365150
The only thing I have a problem with is the fact that there are so few aux inputs.  Most of us today have a number of audio sources and there is only CD, Tape, and Aux for inputs.  This is not enough for most of us today.  I had to add an external switching arrangement.