Database Users

[Q] What Volume SHOULD the speakers achieve? whats the spec

Friends obviously a LOT of Nexus 7 owners have complained about sound issues, from obviously defective units to the simple issue of volume being inadequate for use
My question is what is "normal" on this device? anyone know a db / sound-pressure at radius specification?
other than obvious noise through a speaker, how does anyone know if their unit is "normal" ?

cognus said:
Friends obviously a LOT of Nexus 7 owners have complained about sound issues, from obviously defective units to the simple issue of volume being inadequate for use
My question is what is "normal" on this device? anyone know a db / sound-pressure at radius specification?
other than obvious noise through a speaker, how does anyone know if their unit is "normal" ?
Click to expand...
Click to collapse
My speaker is defective, and in need of going out for repair/replacement, but the volume seems like it will be fine for my needs once the rattle/vibration is fixed. It only happens at certain frequencies, so I can still get a solid sense of the output level.
Trying to determine the exact db at a specific distance isn't going to do you much good, because it will be based on either the loudest frequency, or 1khz. The 1khz rating is somewhat reasonable to use, but what if there's a massive spike there (and on small speakers, there generally is). Say it could hit 95-100db at 1khz, it still will likely only hit about 5db at 40hz. See where I'm going with this?
I don't know, I could grab my spl meter, and run a whole series of tests at 1 meter in a quasi-anechoic environment (though it's really cold outside here), if you're really that keen on finding out precise measurements of the frequency output over the 20-20 range. Seems a little overboard for a 7" tablet though. I would consider the volume more than adequate for listening to the news, or voip calls, but there isn't a tablet that exists where I would be happy with the sound of the speakers for music.
Of course, I'm kind of picky about these things.
From what I see in the boards, there are three types of view points on the output.
1. Plenty good for normal use.
2. Terribly low for music.
3. Flat out broken, so you can only turn it up half way (the second is my current situation).
Also, don't forget that the speaker is in the back, so you'll have to keep it turned around or bouncing straight off of a hard surface, to get the full output to your ears. Some cases may also significantly reduce the output as well.

more questions: if we presume/conclude "there is a volume problem even when the speakers are not defective", then two follow-on questions:
1. is it JUST speakers?
2. combo of lousy speakers and a problem with the DSP/firmware/software/etc.... ?
I think it is 2 but I'd love to hear a root cause on the whole issue.
with SOME music sources I can get through the speakers a little bit louder response, at FULL volume max'd - than I can with MX Player on a video with the Player set on Volume Boost [200%].
in the case of MX Player, its basically worthless through the speakers both from a dynamics standpoint [obvious...] and just volume unless you are in a stone-quiet area and are craning toward the device to hear.... and you have acutely good hearing.
Then, if one is unconcerned about warranty: anyone have suggestions on replacement speaker that perhaps would help?

cognus said:
more questions: if we presume/conclude "there is a volume problem even when the speakers are not defective", then two follow-on questions:
1. is it JUST speakers?
2. combo of lousy speakers and a problem with the DSP/firmware/software/etc.... ?
I think it is 2 but I'd love to hear a root cause on the whole issue.
with SOME music sources I can get through the speakers a little bit louder response, at FULL volume max'd - than I can with MX Player on a video with the Player set on Volume Boost [200%].
in the case of MX Player, its basically worthless through the speakers both from a dynamics standpoint [obvious...] and just volume unless you are in a stone-quiet area and are craning toward the device to hear.... and you have acutely good hearing.
Then, if one is unconcerned about warranty: anyone have suggestions on replacement speaker that perhaps would help?
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Click to collapse
#2
When I connect the Nexus 7 to my car stereo inline, via the headphone output, I get mixed results. I generally have to crank the car stereo way up, which can cause voltage induction through the 1/8" to RCA connector, if I have the Nexus charging simultaneously.
Now granted, induction of this sort is not something that is a Nexus only problem, and has more to do with the quality of cable shielding. If I move the USB charger so that it doesn't line up with the headphone output wire, the problem is reduced.
However, the issue is more that the headphone output is somewhat inconsistent, so that means that some audio will require me to turn the stereo to a level where the inductance is moot, and sometimes I will have to turn up the stereo to the point where charging and listening to audio through the car stereo is just brutal. Of course, you weren't asking specifically about car audio, but it leads to my theory.
Now, here in lies why I think it's you're "#2". If it were purely hardware, there shouldn't be that great of a difference from the headphone jack, assuming relatively similar reference volumes from the source. So software would seem to be at play here, as well as hardware.
As far as the speakers go, I don't think you'll be able to replace the internals. They're a very awkward shape, which probably doesn't help, and there is very little room in there.
Your best bet would be to find out if there is an external speaker option which can easily work for tablets. I listened to an Ipad 4 last night, and it wasn't good either. I think you have to consider the size of these things. A speaker the size of your pinky nail, can only be asked to do so much. Trying to cram one the size of your thumbnail in there, won't do much more, and just wouldn't fit.

now we're talking real issues. thank you.
yes, compared to any of my other android or pc or apple devices this one is uniquely odd
all as you have noted. inconsistent, output device matters, etc.
I admit I'm skewed by the ipad Mini - if you get a chance, sample that in terms of speaker performance. I have not access to Ipad 4 in my shop.
in my case, there is no distortion that I can observe/detect with my ears - clear enough, but there's not much substance there, oddly except for notifications which are crystal clear at full volume, if not particularly loud [my ancient droid optimus is louder - obnoxiously so which is why I keep it on vibe].
bladebarrier said:
#2
When I connect the Nexus 7 to my car stereo inline, via the headphone output, I get mixed results. I generally have to crank the car stereo way up, which can cause voltage induction through the 1/8" to RCA connector, if I have the Nexus charging simultaneously.
Now granted, induction of this sort is not something that is a Nexus only problem, and has more to do with the quality of cable shielding. If I move the USB charger so that it doesn't line up with the headphone output wire, the problem is reduced.
However, the issue is more that the headphone output is somewhat inconsistent, so that means that some audio will require me to turn the stereo to a level where the inductance is moot, and sometimes I will have to turn up the stereo to the point where charging and listening to audio through the car stereo is just brutal. Of course, you weren't asking specifically about car audio, but it leads to my theory.
Now, here in lies why I think it's you're "#2". If it were purely hardware, there shouldn't be that great of a difference from the headphone jack, assuming relatively similar reference volumes from the source. So software would seem to be at play here, as well as hardware.
As far as the speakers go, I don't think you'll be able to replace the internals. They're a very awkward shape, which probably doesn't help, and there is very little room in there.
Your best bet would be to find out if there is an external speaker option which can easily work for tablets. I listened to an Ipad 4 last night, and it wasn't good either. I think you have to consider the size of these things. A speaker the size of your pinky nail, can only be asked to do so much. Trying to cram one the size of your thumbnail in there, won't do much more, and just wouldn't fit.
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Where to start - new Joying Android Head Unit issues

Hi,
I've just installed a new Joying Android Head Unit and I'm pretty disappointed by the sound quality - in fact it's awful - on radio and playing very high quality mp3s - I know it's not the car speakers because they sounded great on the old system.
So I came here wondering if there is anything I can do about it?
I've installed PowerAmp app and tweaked the equalizer, however the sound always sounds tinny - especially noticeable on the base.
At the moment I'm only getting sound from the front speakers which could be a wiring issue..
Looking around I notice there is a soldering solution to fixing the radio sound - is this a general fix for sound output? Anyone tried it?
Finally, would fitting an external amp improve things, or would the signal from the Joying unit still be too poor?

Yeah I completed 7floor's sound mode on mine. It helped with the squashed sound and tinny-ness now the sound is better, not that of a brand name head unit, but better.

welcome to the world of chinese android HUs. Add an external DSP and external amp. That would give you the most noticeable boost. Find a good deal on a used amp from your local craigslist, and for DSP, check out the minidsp 2x4. It's roughly $100 and is fantastic.

Can anyone explain the difference between DSP and Amp, and how this links in with the HU?
I get that the HU has the audio controlled by the Sound Processor IC which is controlled by the MCU - and the point of the mod is to control it via Android.
Does the DSP replace the processing of the Sound processor with/without the MCU, or does it process sound afterwards?
The Amp presumably comes last and only serves to boost the power of the provided signal.
I'm happy to buy a decent dsp and amp, as I think the android unit is fab apart from the sound quality, if the quality I can eventually produce rivals that of a reasonable audio system.
Sorry, but I'm somewhat of a noob when it comes to car audio systems.

dsp -
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4
lets you set electronic cross-overs, equalization, and time alignment. Effectively a super advanced sound processor that overrides the HU sound processing. So what you do is set the HU EQ to flat, so that it's not doing any sound processing to the signal, and let the DSP do the work. the minidsp even has tools that let you auto-eq the system using an app called REW. Similar to how home audio receivers have tools like accueq etc.
an amp is exactly what you say. It becomes essential if you swap out the stock speakers for nicer ones that require more power. They accept low level RCA inputs, as does the DSP, so if you plan to add a DSP you may as well add an amp.
This becomes quite a bit of work to set up, as it's a lot of laborious wiring. But if you want the best sound out of these things, it's the way to go. I hated the stock audio system in my car, so for me it was a no-brainer. I'm on a quest to squeeze the best sound I can out of my unit, and while I'm still not quite there, it's miles better than where it started.

Hisma said:
dsp -
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4
lets you set electronic cross-overs, equalization, and time alignment. Effectively a super advanced sound processor that overrides the HU sound processing. So what you do is set the HU EQ to flat, so that it's not doing any sound processing to the signal, and let the DSP do the work. the minidsp even has tools that let you auto-eq the system using an app called REW. Similar to how home audio receivers have tools like accueq etc.
an amp is exactly what you say. It becomes essential if you swap out the stock speakers for nicer ones that require more power. They accept low level RCA inputs, as does the DSP, so if you plan to add a DSP you may as well add an amp.
This becomes quite a bit of work to set up, as it's a lot of laborious wiring. But if you want the best sound out of these things, it's the way to go. I hated the stock audio system in my car, so for me it was a no-brainer. I'm on a quest to squeeze the best sound I can out of my unit, and while I'm still not quite there, it's miles better than where it started.
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Click to collapse
Did you ever use the mini dsp and if so how was the quality with Android being the source? Did you do the 7floors sound bypass mod as well or is there a better method now? I have 2 amps, 1 mono 1 4channel and would like better control and quality on my rk3188. Thanks

New Car Stereo

I was hoping someone could help.
I need a new 2 Din, Full Android Car Stereo which satisfies the following:
1) Has 4 channels and a subwoofer out
2) The subwoofer out is of normal voltage (ie 4v or above)
3) There is a built in Gain control for the sub on the head unit
4) There is a built in crossover for the speakers and sub so that not too much bass is going to the speakers and not too much mid/treble is going to the sub
5) the above 2 features will be active and work while using 3rd party apps like poweramp etc
All the other stuff like wifi and bluetooth and OBD2 support is assumed as they all seem to do this.
i would appreciate any advice because whenever i email sellers it takes a day to get back to me every time and the answers are always vague and unclear.
many thanks in advance

2-4 I think you're asking too much at this point.. I don't think any of the chinese Android units can meet these requirements at this point. They have SUB output, but no built in crossover which works out of the box. Some units, I believe MTC of sorts, had the hardware but it wasn't hooked up properly, so some people were able to make it work by soldering in some trace wires on the board and moving two resistors. Not something for anyone unless you have good skills in soldering.
For now, I just use an external 3-way active crossover. It works fine. At the moment I'm using the built in amplifier, but will install an amplifier soon as the built in one isn't very powerful, only about 4x15-18W according to the datasheet of the amp IC they used.

Hilari0 said:
2-4 I think you're asking too much at this point.. I don't think any of the chinese Android units can meet these requirements at this point. They have SUB output, but no built in crossover which works out of the box. Some units, I believe MTC of sorts, had the hardware but it wasn't hooked up properly, so some people were able to make it work by soldering in some trace wires on the board and moving two resistors. Not something for anyone unless you have good skills in soldering.
For now, I just use an external 3-way active crossover. It works fine. At the moment I'm using the built in amplifier, but will install an amplifier soon as the built in one isn't very powerful, only about 4x15-18W according to the datasheet of the amp IC they used.
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Hi mate, thanks for your response.
So what i have at the moment is the head unit below:
https://www.amazon.co.uk/dp/B01CGA5...483542345&sr=sr-1&keywords=android+car+stereo
A fitter came and set up my sub and amp from my old car. The rca goes straight from the sub out of the unit into the amp at the back which powers the sub.
The problem i am having is that when i want to hear the sub i have to turn the bass up - when i turn the bass up too high the speakers crackle as the equaliser is universal.
Someone recommended me a PAC LD-10 low pass line which will increase the voltage to the amp for my sub and give me a knob to control the level....will fitting this be enough to do the job?
can you send me a link to your 3-way cross over?
thanks

I'm not using a special crossover by any means, just a standard crossover which are readily available. Not sure the specific one I use, but it looks pretty much identical to this one but with a different color:
http://www.lazada.com.ph/boschmann-mobile-audio-electronic-crossover-23-way-xm-3a-9196761.html
The PAC LD-10 will increase the line level yes, so you get a good signal over 4V. As far as I know, this is a pure preamplifier (or signal booster if you will), without any sort of crossover. It has separate controls for left/right, so you can adjust balance, but that's about it. You can read all about it here:
http://www.pac-audio.com/productDetails.aspx?ProductId=264&CategoryID=28
You get them on Amazon/ebay for $18.49 plus shipping.

Hilari0 said:
I'm not using a special crossover by any means, just a standard crossover which are readily available. Not sure the specific one I use, but it looks pretty much identical to this one but with a different color:
http://www.lazada.com.ph/boschmann-mobile-audio-electronic-crossover-23-way-xm-3a-9196761.html
The PAC LD-10 will increase the line level yes, so you get a good signal over 4V. As far as I know, this is a pure preamplifier (or signal booster if you will), without any sort of crossover. It has separate controls for left/right, so you can adjust balance, but that's about it. You can read all about it here:
http://www.pac-audio.com/productDetails.aspx?ProductId=264&CategoryID=28
You get them on Amazon/ebay for $18.49 plus shipping.
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Thanks mate.
Does the sub-out on my unit not limit the frequency to say 120 or 150 and below? So hopefully i will just need a crossover for the speakers...?
So if i need a PAC LD-10 for the sub and a crossover for the speakers will my battery be able to cope with powering both of those as well as the Head Unit?

When I hooked up the subwoofer in my car to the SUB output on my head unit, it sounded awful. It seemed to play full range sound without any crossover, and the sound was greatly improved when I installed the crossover. I didn't have an issue with it being too low though, so depending on the way your amplifier and head unit is designed, your results may vary. If you plan on using aftermarket amplifiers for all the speakers, I recommend using an external crossover, either one like I use or the one that is built in on the amplifiers themselves, as many come with that already.

Hilari0 said:
When I hooked up the subwoofer in my car to the SUB output on my head unit, it sounded awful. It seemed to play full range sound without any crossover, and the sound was greatly improved when I installed the crossover. I didn't have an issue with it being too low though, so depending on the way your amplifier and head unit is designed, your results may vary. If you plan on using aftermarket amplifiers for all the speakers, I recommend using an external crossover, either one like I use or the one that is built in on the amplifiers themselves, as many come with that already.
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the amp connected to my sub has a built in filter and gain. The gain is on max but i can only hear the sub properly when i turn the bass up on my equaliser, but it still doesnt thump like it did in my old car. The other issue is that the speakers crackles as soon as you start turning the volume up after that. I dont think i need an amp for the speakers as they can even take the Head Units power as they crackle when i turn it up....unless this is becasue the audio quality is so bad.....jesus i never realised this would be so complicated when i had it fitted.

i forgot to remind you as well - will the normal car battery power these devices and headunit...and i also have my amp in the boot...

Speakers will always perform better with a strong amp vs a weak amp. And a weak amp can make good speakers crackle even if they're far from their max power output, due to the amplifier not being able to handle the load. If you have a car with a proprietary amplifier system which uses weird inputs, it may be a challenge to make it work properly and you might be better served replacing that amplifier with an aftermarket one. Don't throw the stock factory amp away, if you ever want to reinstall the OEM system when you sell it or similar. If not, selling it may give a nice income as some of these go for a premium.
---------- Post added at 01:03 AM ---------- Previous post was at 12:59 AM ----------
Oh, and yeah. A standard car battery and alternator should be able to handle a normal sized sound system, even if it's aftermarket. I wouldn't be worried about installing a head unit, a 4x50W amp and a monoblock amp for the subwoofer. Perhaps I'd go to the step of installing a capacitor if the subwoofer was more than 200W and the dash lights started dimming, but this is usually only an issue if you install a huge sound system. Normal listening levels never reaches high power demands..

Hilari0 said:
Speakers will always perform better with a strong amp vs a weak amp. And a weak amp can make good speakers crackle even if they're far from their max power output, due to the amplifier not being able to handle the load. If you have a car with a proprietary amplifier system which uses weird inputs, it may be a challenge to make it work properly and you might be better served replacing that amplifier with an aftermarket one. Don't throw the stock factory amp away, if you ever want to reinstall the OEM system when you sell it or similar. If not, selling it may give a nice income as some of these go for a premium.
---------- Post added at 01:03 AM ---------- Previous post was at 12:59 AM ----------
Oh, and yeah. A standard car battery and alternator should be able to handle a normal sized sound system, even if it's aftermarket. I wouldn't be worried about installing a head unit, a 4x50W amp and a monoblock amp for the subwoofer. Perhaps I'd go to the step of installing a capacitor if the subwoofer was more than 200W and the dash lights started dimming, but this is usually only an issue if you install a huge sound system. Normal listening levels never reaches high power demands..
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spot on mate - the major issue with my oem kit is that it was fibre optic from the main head unit to the back amp. However the guy that fitted the stereo for me asured me that the power from the HU would be more than enough to power the speakers in the car...looks like he was wrong!
So in summary i can buy one of these as the amp for the 4 speakers
http://www.crutchfield.com/S-JbbC3Sa3qOK/p_500MRVF300/Alpine-MRV-F300.html
And then get the PAC LD-10 for the sub and that should be me done right? In theory...LOL

I don't see any reason why it shouldn't work, but I don't know anything about the headunit you have so I have no idea if it has good or bad preamp outputs. It does look like a pretty standard Rockchip based unit, so I suppose it would work fine.
Powering speakers with the built in amplifier works, but only to a certain point. It's mostly good for your bog standard OEM speakers from a mid to low class vehicle. Anything premium or larger setup in a luxury vehicle typically requires a bit more power than the internal one can give. I know they write 4x50W on the box for the head unit, but that number is a peak output power at 10% THD or something, horribly overrated. hehe. Not sure if your head unit uses the same amp IC as the Joying ones, but I checked the datasheet on that and it was at 4x15W at 4 ohms when it crossed the 0.1% THD mark, and you typically don't want to go beyond that.

Hilari0 said:
I don't see any reason why it shouldn't work, but I don't know anything about the headunit you have so I have no idea if it has good or bad preamp outputs. It does look like a pretty standard Rockchip based unit, so I suppose it would work fine.
Powering speakers with the built in amplifier works, but only to a certain point. It's mostly good for your bog standard OEM speakers from a mid to low class vehicle. Anything premium or larger setup in a luxury vehicle typically requires a bit more power than the internal one can give. I know they write 4x50W on the box for the head unit, but that number is a peak output power at 10% THD or something, horribly overrated. hehe. Not sure if your head unit uses the same amp IC as the Joying ones, but I checked the datasheet on that and it was at 4x15W at 4 ohms when it crossed the 0.1% THD mark, and you typically don't want to go beyond that.
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ok - i have booked in the fitting;
- a 4 x 50w rms amp with variable crossover for the speakers
- Line driver for the sub with variable gain
One more question. I have an RMA set up on the Head Unit. Is there a "best full android head unit" that i can buy and send this one back?
I want the unit with the best balance of being fast cpu (the one i have does lag a bit when trying to go in and out of apps and i am not used to that as i have always had decent android devices - it can be very frustrating), enough ram and 16gb storage minimum and also better sound quality than the one i have.
From what i gather they are all pretty similar in regard to the above but is there one out at the moment which stands out from the rest in terms of sound quality but keeps the full android and decent cpu?

Well, at the moment the best units around is the Intel Sofia based units with 2GB ram, they come with 32GB internal storage as well. I have the Joying JY-UL135N2 and I'm happy with it. As with all of the chinese Android head units, it has a few quirks, but it doesn't have any dealbreaking stuff. Plus it has fully working Bluetooth, just that they removed it from the Settings menu.. hehe. There's a thread here on the forum on how to make the full stock Bluetooth settings open, so that's really great!
Here's my head unit: https://www.carjoying.com/joying-ne...-wifi-mirror-link-entertainment-multimed.html
And here's the thread for full bluetooth: https://forum.xda-developers.com/an...elopment/bluetooth-settings-launcher-t3504526
The biggest problem with it is that it doesn't have a good heatsink on it, so the CPU gets pretty hot. It still performs smoothly, so not a big issue but I don't like that it runs so hot so personally I'm gonna attach an Intel stock CPU cooler from a desktop with thermal epoxy, and that should take care of it.

Hilari0 said:
Well, at the moment the best units around is the Intel Sofia based units with 2GB ram, they come with 32GB internal storage as well. I have the Joying JY-UL135N2 and I'm happy with it. As with all of the chinese Android head units, it has a few quirks, but it doesn't have any dealbreaking stuff. Plus it has fully working Bluetooth, just that they removed it from the Settings menu.. hehe. There's a thread here on the forum on how to make the full stock Bluetooth settings open, so that's really great!
Here's my head unit: https://www.carjoying.com/joying-ne...-wifi-mirror-link-entertainment-multimed.html
And here's the thread for full bluetooth: https://forum.xda-developers.com/an...elopment/bluetooth-settings-launcher-t3504526
The biggest problem with it is that it doesn't have a good heatsink on it, so the CPU gets pretty hot. It still performs smoothly, so not a big issue but I don't like that it runs so hot so personally I'm gonna attach an Intel stock CPU cooler from a desktop with thermal epoxy, and that should take care of it.
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ok great. I appreciate this
so just to clarify, with your stereo, there is no Bluetooth in the settings? So is there no way to pair your phone to make/receive calls unless i use this workaround? Why in the hell would they do that??
Also does this unit have usb flash ports so i can plug my 128gb flash drive in?
Also does it have sub-out?

nk33 said:
ok great. I appreciate this
so just to clarify, with your stereo, there is no Bluetooth in the settings? So is there no way to pair your phone to make/receive calls unless i use this workaround? Why in the hell would they do that??
Also does this unit have usb flash ports so i can plug my 128gb flash drive in?
Also does it have sub-out?
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EDIT
Actually i can see the sub -out.
It says bluetooth 4 on the site....if i only want to use the Bluetooth for making calls etc i am assuming i wont need to do the mod?
i use wifi tethering from my phone anyway - not Bluetooth - i am assuming this stereo will be ok with this.
damn this stereo looks good.
should i be worried about the heat? i am seriously thinking of buying this and getting them to fit it along with the other equipment...and send the other one back for a refund

The bluetooth works out of the box, but it's somewhat limited with their not so good bluetooth dialer app. It works to call and such, and limited pairing, but you only get full use of it if you do the mod mentioned in that thread. It's pretty easy to do that mod though. And yes, it has sub out but there's no built in crossover or anything.

Most likely it will work well despite the heat. In the worst case, would you be comfortable in opening it and installing a heatsink on it? Thermal epoxy seems to be the way to go there, Arctic Alumina Thermal Adhesive is the one I'm gonna use, just waiting for it to show up in the mail.
http://www.arcticsilver.com/arctic_alumina_thermal_adhesive.htm

Hilari0 said:
Most likely it will work well despite the heat. In the worst case, would you be comfortable in opening it and installing a heatsink on it? Thermal epoxy seems to be the way to go there, Arctic Alumina Thermal Adhesive is the one I'm gonna use, just waiting for it to show up in the mail.
http://www.arcticsilver.com/arctic_alumina_thermal_adhesive.htm
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Ok, I have ordered the head unit you have.
I will ask the fitter if he is willing to add a heatsink for me.
If it has an intel sofia processor… surely the processor has a heatsync gel and hearsink already?? It surely will overheat without one…?
Tell me are the audio specs better than my current unit? What is the rms on the speakers and the sub out voltage?
Sent from my SM-G925F using XDA Free mobile app

I have no idea what the output voltage is on the sub or preamp outputs, but the built in amp is 4x15-18W rms at 0,1 %thd. I can post a datasheet to the amplifier IC they use if you want. The sub output seems loud enough, I just use an active crossover on it with the gain set at 0 db.

@Hilari0 I disagree that the sofia units are the best. Mainly because the whole chipset was a failure and development stopped and you will never get updates and never see android 6 even. So after 2 years it is garbage. Also MTK based quad core units are slightly faster and support Android 6, 4G/LTE etc. natively.
http://www.pcworld.com/article/3063...-tablet-markets-after-cutting-atom-chips.html
I myself bought an Ownice C500 after considering all the options. It was also cheaper and so far there does not seem to be any problems reported. The only downside is that it has 16GB storage, but well I am thinking I will stick in an SD card if it ever becomes a problem.
Also C500 units have a subwoofer out but I don't know if it completely satisfies the requirements of the OP. I just ordered a C500 unit myself and waiting for it although I won't use the subwoofer out.

Running at high volume safe?

I've recently fitted an Xtrons PB88UNVP (MTCE_GS_V2.88_3) PX5 headunit. The speaker power is 4x45W (probably pretty standard on these things) and generally sounds good.
However, it's quieter than my previous WinCE unit and I find I have to run it higher up the volume scale for a decent listening volume.
Sometimes I like my music loud, and I can turn it up to MAX (30) without deafening myself or even experiencing clipping from the headunit's amplifier - output is still clean and undistorted. I'm running the EQ fairly flat and Loudness is set to ON.
My question is - NOT what volume should I be listening at in my car to still hear the engine, traffic around me and be safe on the roads - BUT is it safe to run these headunits at 25-30 (83-100%) continuously/for extended periods? Will it overheat or be damaged by running at this sort of volume?
Thanks

I noticed the exact same thing - again, compared to my previous WinCE units, just like you. These Android units just seem significantly less powerful in comparison. I have a feeling that the 45Wx4 max rating (I know it's not RMS) is a little on the "wishful thinking" side. My WinCE units (18->25Wx4 RMS, 50Wx4 max) seemed considerably more powerful.
I haven't seen these Android units list the RMS power, but I have a feeling it's lower than a lot of the older WinCE units. It also seems like the volume scale is just "different" - it doesn't start getting even somewhat loud until the volume is 2/3rd's of the way up or higher.
It's really hard to say if they are clipping or not in those upper ranges, but I have a feeling they may be - depending on how you have the EQ set - even if you can't hear the distortion.
To me, it seems like you have to sacrifice a lot on the audio side of things for the flexibility that you get from Android.

@jtrosky: I have noticed distortion when the EQ is set to the Rock preset, which is very bass-heavy, and is turned up high. I don't personally like heavily biased EQ profiles and would prefer to run it as flat as possible across the frequency spectrum. A little bit of tuning seems to help these units particularly though. I agree with you that their amplifiers are weak, or rather underpowered. That said, my experience so far is that at medium volumes it sounds alright, to the extent that I didn't notice my sub wasn't working at first.
So do you regularly run yours at two thirds volume or above and do you think they can handle it for a sustained period?
Has anyone ever fried one of these?

Honestly, I connected an amp shortly after installing, so I can't say how they would last over time if used at louder volumes frequently with the internal amp. To me, it seems like they have the volume control setup in a way where it doesn't get very loud until at least 2/3rd's volume - and then every click makes a substantial difference. So I wonder if they just have the volume scale "tuned" differenlty than other head-units? But my point was that the unit can be clipping without you even hearing any distortion - clipping is not always audible. I had a LOC hooked up for testing briefly and it had a "clipping" light - and I was seeing clipping way before any distortion was audible. I think these units use pretty poor quality amps.
I've actually removed the Android head-unit completely and went back to my older WinCE-based unit. Just was not happy with the Android unit (sound quality, noise-related issues, etc).

I've actually removed the Android head-unit completely and went back to my older WinCE-based unit. Just was not happy with the Android unit (sound quality, noise-related issues, etc).
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Click to collapse
That's sad to hear. I deliberated for so long before taking the plunge and buying one. I like the Android platform, and the few niggles I have with mine aren't sufficient to make me want to change it... yet.
I must admit though, when I made my first post I had been listening to DAB, which is probably the quietest source. FM is probably 15% louder at the same volume setting, and is the loudest of all the sources. I don't know if there is any way to make this louder, as a USB device, and there is no volume 'boost' option within realzoulou's DAB-Z app (only a <= 100% setting).
FM on full whack does distort a bit, but it's too loud to listen to constantly, so while a bit weak I think the on-board amp should be capable of more.
Better control of volume on different sources within Android would be nice, do you know if this is possible?

You can alter the volume of each source in the Factory Settings, under the "Voice" tab...
If you are coming from a stock radio with stock speakers, the Android head-units may be an upgrade in terms of sound-quality. But for me, coming from an aftermarket, high-quality WinCE unit, the sound quality just wasn't up to par. The WinCE unit I'm referring to (Dynavin N7) has high-quality audio components though (4V pre-outs, "high-resolution Burr Brown 24-Bit Digital to Analogue converters", etc) - so once I got used to the sound quality of the Dynavin (or even the Rosen GM1010 befoer it), it was hard switching over to the Android unit. Believe me, I went to great lengths to make it work, but it just wasn't mean to be, considering the sound-quality downgrade and the noise-related issues I had with the Android unit.
Don't get me wrong - I liked almost everything about having full-blown Android as the OS - it's just the sound quality that I wasn't 100% happy with - which, to me, is very important.

Viper4Android for cars

I've seen a few posts recently about how to set up Viper4Android on an Android head unit, so thought I would start this thread so that we could share some ideas. The configuration that I posted below is what I came up with in 15 minutes of experimenting yesterday. It's not a definitive or optimum config, it's just what I came up with, but I am very happy with the result. The purpose of this thread is to share ideas and configurations, due to there being a complete lack of this kind of information anywhere else that I could find.
First, a disclaimer: I'm half deaf, have constant ringing in my ears, and I am most definately not an audiophile, so take anything I say below with a grain of salt. Having said that, I do appreciate clarity when listening to music, so that is always my priority.
So I installed an android head unit in my car last week, installed the Hal9k ROM which came with Viper4Android (V4A) pre-installed. I've played around with V4A on my phone before with goods results, it's mainly geared towards phones with earphones, so don't expect too much from it using it in the car. But I played around with it yesterday and came up with a setup that I am really happy with, it gives in my opinion a richer, fuller sound, with no loss of clarity.
So here is what I did:
1) Select the speaker icon down the bottom. The headphone setup certainly has a lot more options available, but I went with the speaker setup as that's what I'm using.
2) Turn on the Master Limiter
3) I turned on Playback Gain control for a specific reason. My head unit has a bit of hiss with no signal at very high volumes. I can't hear it while the engine is running, but it's there. Bumping up the playback gain control let me turn down the gain on the head unit (look in Factory Settings) which reduced the hiss, but without any clipping or distortion that I can hear. I set Strength to 2, Max Gain to 9x, and output threshold to -1db.
4) I turned on the FIR equaliser. I was using the equaliser in the Amplifier app that came with my head unit, but I would rather just have all of these settings in one place, so I set the Amp equaliser to flat, and made all of my adjustments within the FIR equaliser. My setup tends to be a bit bass-heavy to my ears, so I just use the equaliser to gently taper off the bass, and I leave everything else flat. But just adjust it so that it sounds right to you in your car with your choice of music.
5) I turned on Reverberation. I dare say many will scoff at this, but I like the effect. It makes the sound more "full", without any loss of clarity that I can hear. I used fairly minimal settings to achieve this effect. Room size = 25m2, Sound Field = 6m, Damping Factor = 20%, Wet Signal= 20%, Dry Signal = 50%.
And that's what I came up with in 15 minutes. I'm really happy with the result though. Hopefully that will give others a starting point to do some more experimentation. And if you have your own ideas, please share them here

jrobbom5 said:
I've seen a few posts recently about how to set up Viper4Android on an Android head unit, so thought I would start this thread so that we could share some ideas. The configuration that I posted below is what I came up with in 15 minutes of experimenting yesterday. It's not a definitive or optimum config, it's just what I came up with, but I am very happy with the result. The purpose of this thread is to share ideas and configurations, due to there being a complete lack of this kind of information anywhere else that I could find.
First, a disclaimer: I'm half deaf, have constant ringing in my ears, and I am most definately not an audiophile, so take anything I say below with a grain of salt. Having said that, I do appreciate clarity when listening to music, so that is always my priority.
So I installed an android head unit in my car last week, installed the Hal9k ROM which came with Viper4Android (V4A) pre-installed. I've played around with V4A on my phone before with goods results, it's mainly geared towards phones with earphones, so don't expect too much from it using it in the car. But I played around with it yesterday and came up with a setup that I am really happy with, it gives in my opinion a richer, fuller sound, with no loss of clarity.
So here is what I did:
1) Select the speaker icon down the bottom. The headphone setup certainly has a lot more options available, but I went with the speaker setup as that's what I'm using.
2) Turn on the Master Limiter
3) I turned on Playback Gain control for a specific reason. My head unit has a bit of hiss with no signal at very high volumes. I can't hear it while the engine is running, but it's there. Bumping up the playback gain control let me turn down the gain on the head unit (look in Factory Settings) which reduced the hiss, but without any clipping or distortion that I can hear. I set Strength to 2, Max Gain to 9x, and output threshold to -1db.
4) I turned on the FIR equaliser. I was using the equaliser in the Amplifier app that came with my head unit, but I would rather just have all of these settings in one place, so I set the Amp equaliser to flat, and made all of my adjustments within the FIR equaliser. My setup tends to be a bit bass-heavy to my ears, so I just use the equaliser to gently taper off the bass, and I leave everything else flat. But just adjust it so that it sounds right to you in your car with your choice of music.
5) I turned on Reverberation. I dare say many will scoff at this, but I like the effect. It makes the sound more "full", without any loss of clarity that I can hear. I used fairly minimal settings to achieve this effect. Room size = 25m2, Sound Field = 6m, Damping Factor = 20%, Wet Signal= 20%, Dry Signal = 50%.
And that's what I came up with in 15 minutes. I'm really happy with the result though. Hopefully that will give others a starting point to do some more experimentation. And if you have your own ideas, please share them here
Click to expand...
Click to collapse
I downloaded Malay Mod {and got the Full Version}. It also came with V4A but I hear no difference no matter what I've got selected. Mine has "Headset - Phone Speaker - Bluetooth Device - USB/Dock" tried them all ..
My headunit pushes amps via RCAs, so maybe it doesn't work through those channels?
Good ideas on your tuning {I've for tinnitus too}.