# HELIX HEC USB VS BT THE REALITY



## audiocholic (Dec 5, 2016)

Hi guys,



I have come accross 2 local realtime end users claiming nothing was gained even though on paper specs state otherwise and that bt was more then great but we always want better right  well is usb really better do we notice any sonic improvement?


has anybody went from Helix HEC BT to upgrade to HEC USB and can chime in and comment there findings?


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## audiocholic (Dec 5, 2016)

no one wants to chime in for this old fella?


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## Souths1der (Aug 27, 2014)

I started with the HEC USB. I had some issues. I'm an android user and I could never find a OTG cable that reliably charged the phone while connected to the Helix. About once a week it just wouldn't connect. I would have to do a combo of disconnect-reconnect and switching the speed until it finally connected. So I switched to the BT one and was more pleased. No connection issues. Phone could also be charging. I could connect. I thought everything sounded the same, nice and clear. I stream primarily, so I don't have a huge frame of reference. I'm working on moving more toward using a DAP player though.


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## tonynca (Dec 4, 2009)

If you have Tidal Masters or some other hi-res streaming get the USB. If you have Spotify get Bluetooth.

The biggest difference between Tidal Hi-Res (24bit/96khz) and Spotify 320kbps is separation and clarity. I would switch between the two and I could hear a night and day difference. If you are feeding the USB dac vs Bluetooth Spotify the difference will be a lot less.


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## jrwalte (Mar 27, 2008)

As said, your source material is all that matters. A connection cannot be any better than the source. A streaming service like spotify is one of the worst so bt would be perfectly fine. You use hi rez files played back on phone or tidal hifi and you will get an advantage to using a wired usb connection.

But then not everyone will notice the difference, depending on their audio equipment and themselves.

Personally i use android auto wireless. It's the same quality as wired.

Sent from my SM-N960U using Tapatalk


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## audiocholic (Dec 5, 2016)

tonynca said:


> If you have Tidal Masters or some other hi-res streaming get the USB. If you have Spotify get Bluetooth.
> 
> The biggest difference between Tidal Hi-Res (24bit/96khz) and Spotify 320kbps is separation and clarity. I would switch between the two and I could hear a night and day difference. If you are feeding the USB dac vs Bluetooth Spotify the difference will be a lot less.



the source unit will be LG V30 plus (this phone does support hi res etc)
and indeed I will be using Tidal as an app.


so in this case I should gather there will be a noticeable difference between hec bt and hec usb and that I should definatley go for hec usb correct?


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## audiocholic (Dec 5, 2016)

Souths1der said:


> I started with the HEC USB. I had some issues. I'm an android user and I could never find a OTG cable that reliably charged the phone while connected to the Helix. About once a week it just wouldn't connect. I would have to do a combo of disconnect-reconnect and switching the speed until it finally connected. So I switched to the BT one and was more pleased. No connection issues. Phone could also be charging. I could connect. I thought everything sounded the same, nice and clear. I stream primarily, so I don't have a huge frame of reference. I'm working on moving more toward using a DAP player though.



Thanks for the reply, I too use an android (LG V30 plus) though I dont mind not being able to charge the phone as I do a 40min one way trip and my phone barely looses %10 charge on this journey ,can always recharge at the office/house


so in this case if I'am not after a OTG cable that will both charge the phone and connect to the phone/dsp will all be ok?

I mean if I just go phone usb out to helix dsp is there still chances I will face connection issues like you did yourself?


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## Twonks (Nov 10, 2007)

I started with an android phone into a P-Six via a BT card and APTx signal. Worked well enough but the phone kept interrupting advising me to turn the volume down before I damaged my ears (was on full volume to ensure the best signal into the DSP), and I got occasional half second drop outs.

Combined with the hassle of not being able to charge as I couldn't find the right OTG cable meant I got a USB card, ipod shuffle and camera kit as soon as I could. Much better usability (until recently when Apple decided not to support the USB audio to Helix and stopped charging it).

I do prefer the USB Audio android app over all, so if the problems have been solved in the few years since I used it, the BT card isn't a bad option.


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## jrwalte (Mar 27, 2008)

Twonks said:


> I do prefer the USB Audio android app over all, so if the problems have been solved in the few years since I used it, the BT card isn't a bad option.


This comment is contradictory... USB Audio but over BT? I don't get it.

You could try using the Android Auto app on the phone. Even without using a HU interface, the app may lock the usb audio output to line level like it does for the HU.


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## Twonks (Nov 10, 2007)

jrwalte said:


> Twonks said:
> 
> 
> > I do prefer the USB Audio android app over all, so if the problems have been solved in the few years since I used it, the BT card isn't a bad option.
> ...


Sorry, I should clarify. I prefer the usb audio app as a front end over all others. Think I used it initially with the bt connection and of course the usb audio whilst I had android. 

Not sure how the app works nowadays as it’s years since I last used it.


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## Loud Residence (Feb 7, 2020)

Do you know if the hec bt module for a helix dsp pro mk2 is compatible with the helix dsp ultra? I have a helix dsp ultra and someone is selling his hec bt module that he had in a helix dsp pro mk2. Just wanted to know if it will work in the helix dsp ultra?


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## Bnlcmbcar (Aug 23, 2016)

I know the *USB HEC* from my Pro Mk2 was the same and fully compatible in my Ultra.

The only difference was the cover plate.


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## crdi_lover (Jul 19, 2018)

Loud Residence said:


> Do you know if the hec bt module for a helix dsp pro mk2 is compatible with the helix dsp ultra? I have a helix dsp ultra and someone is selling his hec bt module that he had in a helix dsp pro mk2. Just wanted to know if it will work in the helix dsp ultra?


Browsing Audiotec-Fischer website, both the HEC-BT modules are different and DSP specific. 

HEC-BT for DSP PRO/MK2 PRO









HEC-BT for ULTRA


















Sent from my ONEPLUS A3003 using Tapatalk


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## Bnlcmbcar (Aug 23, 2016)

Pretty certain it is the same module just different cover plates.

I installed and used my MK2 USB HEC in my Ultra while I was waiting for the Ultra USB HEC to arrive.

HEC modules come with a specific cover plate that is matched to the specific DSP dimensions. Once you install the HEC module the stock cover plate does not have openings for the added HEC module feature, like an opening for the usb input for the USB HEC module or a spot for the Antenna for the BT HEC.

The module itself is the same.

If you use a HEC from the MK2 for the Ultra:

1) You would have to buy a cover plate individually. (Check with dealer if they are willing to.)

or

2)Drill/Create opening on original stock plate

or

3) Not use a cover plate or fabricate one yourself

or

4) Sell the MK2 HEC and just buy the HEC kit for the Ultra


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## Loud Residence (Feb 7, 2020)

Do you know what hec is better? The hec or the hec bt?


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## Bnlcmbcar (Aug 23, 2016)

Never used the BT HEC so I cant offer much on that.

As of now, using the USB HEC is the most direct and hi res signal input for a Helix DSP.

USB HEC is at 192 kHz / 32 bit (USB Audio)
Digital Coax is at 192 kHz / 24 bit (SPDIF)
Digital Optical is at 96 kHz / 24bit (SPDIF)
BT HEC is at 44.1 kHz / 16bit (aptX codec and A2DP codec)
What your ears can perceive as far as bitrates vs your value of a wireless connection will have to be the deciding factors.


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## rivkinbangayan (Mar 8, 2019)

For those iOS users experiencing charging problem with the USB hec with camera kit, I noticed that my phone only charges when I plug it in with 50% or more battery. 


Sent from my iPhone using Tapatalk


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## dumdum (Feb 27, 2007)

tonynca said:


> If you have Tidal Masters or some other hi-res streaming get the USB. If you have Spotify get Bluetooth.
> 
> The biggest difference between Tidal Hi-Res (24bit/96khz) and Spotify 320kbps is separation and clarity. I would switch between the two and I could hear a night and day difference. If you are feeding the USB dac vs Bluetooth Spotify the difference will be a lot less.


Usb hec is no better sounding than my pioneer dab headunit, ie poor compared to digital direct into the processor via coax, there is a thread occurring at the minute, I am going to add in frequency responses with the same file from the same source into my ultra of a usb hec vs a cheaper topping D10 (granted the topping measures excellently, but it still costs way less than a usb or bt hec)

I have topping vs bt hec was night and day when you look at the freq response (particularly the low end sub 80hz... was pretty much the same above 80hz to 19.5khz, but also more detailed, better, higher soundstage with more separation between instruments etc hence why I checked freq response to see if it was that I was hearing), but I will say the bt hec had more detail than my alpine 178bt for the same frequency response except the bass end (again mid and treble was similar except the top end rolled off early (I measured the alpine via usb and vs bt vs the bt hec vs a topping d10 via coax


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## Bnlcmbcar (Aug 23, 2016)

dumdum said:


> Usb hec is no better sounding than my pioneer dab headunit, ie poor compared to digital direct into the processor via coax, there is a thread occurring at the minute,


What where you using as a source for your USB input? The same D10 Topping?

If not, I wouldn’t go as far to say that as a ‘definitive’ just yet regarding the the USB input being worse than the Coax input.

Definitely post your findings and share but remember that is what they are with your given equipment. A more solid test would be to use the same digital player source for both the USB input and coax input to better compare the input
differences.

Using a phone or device on the USB and using a different device like the Topping D10 on the Coax is not truly a precise comparison/experiment.


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## dumdum (Feb 27, 2007)

Bnlcmbcar said:


> What where you using as a source for your USB input? The same D10 Topping?
> 
> If not, I wouldn’t go as far to say that as a ‘definitive’ just yet regarding the the USB input being worse than the Coax input.
> 
> ...


In my first test I was using my iPhone XR as a source into the topping, bt hec and alpine headunit via bt and usb

Currently using a Samsung tab a 10.1” when I began using the usb hec, I had a good ten days using that, and then I dropped the topping in on weds night and have had 12+hrs listening (mainly because peter (ps sound sent me three playlists and I lost 5-6hrs on the weds night  )


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