ARK

Hi Guys,

I finally got around to getting a Grom adapter with Bluetooth dongle and installing it in my 08 40th Ed. I seem to be having a sound quality issue with music over Bluetooth and am looking for someone who has one of these to do a little comparison for me.

Could you play music over BT then connect your 3.5mm line in and play the same track over that line. Do you hear any difference? With mine, the BT has a pretty bad "hollow" sound, almost and echo. It is like the stereo separation is being greatly exaggerated.

I have a different BT adapter which I use with this phone (Nexus One) and sound through that is indistinguishable from the 3.5mm line.

I'm emailing back and forth with Grom support over this but sense a response of "that's typical for BT" is coming from them soon.

Thanks!

Addicted2speed

Sorry I can't offer a solution, but I just bought the Grom set up a week ago and am experiencing the same issue with my iPhone. If you do get a useful response from Grom, let me know, I would be interested to hear if this is common or if there is a fix for it.

Thanks

firebirdude

iTrader: (3)

The closest I've experienced is with my Pioneer D3 and Blackberry Tour. I streamed audio, but the sound quality and overall loudness sucked.

In addition, I've also used the Jawbone Jambox with bluetooth quite a bit. Exact same results. Sounds much better with the 3.5mm jack.

So though GROM's answer may seem short and a little rude, I think they're correct.

ARK

Thanks for the replies so far.

To elaborate a little more about what I have learned from Grom, their BT uses the SBC codec (common to all BT devices) to compress the audio stream. Grom has suggested that the problem lies with this codec and not their hardware. This certainly could be the case. Re-compressing compressed music with a poor codec could certainly cause some nasty artifacting. Enhanced stereo separation still seems like a weird thing for a codec to cause though...

I paraphrased a bit about their response; they have actually been very good with communication and support so far. I've exchanged 6 or 7 emails with them and support seems to have a good technical knowledge of the product.

That said, I have another BT device (Nexus One Desktop Dock) which streams audio through BT and there is no discernable difference in audio quality between BT and 3.5mm on this. Grom surmises that this device is using a better codec than SBC, which is possible. Not sure if Grom has any plans for upgrading codecs in the future.

I'll update as I learn more.

ARK

Interesting. Grom told me that they test with iphone 4 ios5 and have not been able to reproduce the problem. I'll get my hands on an iphone and test it in my car.

firebirdude

iTrader: (3)

It could simply be that the Nexus One Desktop Dock is much smaller. Maybe you simply can't notice the degradation on that system? Where as sitting in the RX8 and surrounded with 7+ speakers makes it a little easier.

It's like listening to a 128kbps song with headphones, then listening to the same file in the car. Sounds like complete crap in the car.

ARK

Oh, a little confusion, my bad. The nexus one dock is just a little cradle with a line out, no speakers. I had the nexus one dock connected to the Grom 3.5mm line in, in the RX-8. I couldn't tell the difference between BT over nexus one dock and straight 3.5mm from the phone. The difference is very noticeable with Grom BT and 3.5mm though.

Looking into the BT A2DP standard, it requires the implementation of the SBC codec for streaming audio to be in all BT devices, but does not forbid the use of other codecs. It is possible nexus one dock is using a smarter codec than SBC. Although I still have a hard time believing the SBC codec is really that bad.

firebirdude

iTrader: (3)

Oh true. I know what the Nexus is. So I just assumed it was a docking station with speakers. lol

Gerald Nunn

What a coincidence, I also have the 40th anniversary with the GROM installed. My audio through BT isn't great but then I'm not a big fan of the Bose sound system anyways so I just wrote it off as the stereo. The BT doesn't sound any worse then FM to me, however I'll test the difference between line in and the BT tomorrow and post back the results.

ARK

Great, thanks Gerald. Please mention what device you are able to test the BT with. I'm going to borrow someones iphone 4 this weekend to test with mine.

Gerald Nunn

I'm using a Samsung Galaxy II

Gerald Nunn

Well I tried it with my Galaxy S2 and I don't notice any significant difference between the line in and BT. The line in sounds maybe a tad fuller but the difference is pretty imperceptible to my ears, certainly not enough for me to give up the convenience of BT and switch to line in. Keep in mind though I have tin ears and don't consider myself an audiophile. Also I'm already prejudiced against the Bose in the Rx-8 as it sounds a bit hollow to me compared to the Toyota premium system I had in my previous car, a Celica.

Maui

Quick question. The bluetooth uses the "EXT" entry. If you connect your phone, do you use the USB entry or do you have to unplug the bluetooth to do it?
I just ordered the Grom USB + the BT thing. So, I'm just wondering.
Thanks!

Edit:
DUH! nevermind, it has 2 mini-din ports.

Edit #2:
I hope this second question is not as stupid as my first.
Where do you leave the bluetooth flat thingy. I'm thinking to route it all the way through the center console and out on the storage area. I usually leave my phone there connected to the charger. Is this what all of you are doing or do you leave it near the head unit?

Nopstnz8

iTrader: (6)

So with this unit for say the iPhone 4, is it not possible to play music through the dock connector (I highly prefer this over bluetooth playback) but for answer calls, can that then be done over bluetooth without having to switch back and interuptedly? Basically, I love my orignal GROM unit I got years ago, but I'm looking for a way to answer calls without having to plug in an rca connector.

Nopstnz8

iTrader: (6)

Bump