Is the DSP stereo's bass weaker than standard 10-speaker?

[bluesandbmws]

I have a 07 M Roadster - without Nav.
In my car, using the aux input results in a major loss of bass.
Bass is fine with MP3 discs! I've done a/b tests between the mp3s and my ipod and the difference is huge. I'm not sure why this happens, but I've moved to using mp3s almost exclusively for this reason.
You may want to try mp3s before making any changes to your system.

[CFoote]

Originally Posted by bluesandbmws

I have a 07 M Roadster - without Nav.
In my car, using the aux input results in a major loss of bass.
Bass is fine with MP3 discs! I've done a/b tests between the mp3s and my ipod and the difference is huge. I'm not sure why this happens, but I've moved to using mp3s almost exclusively for this reason.
You may want to try mp3s before making any changes to your system.

I agree that the AUX Input weakens the signal. I have the "EQ" set to "Rock" on my IPhone and it helps a bit...

Chris

[chickdr]

Originally Posted by CFoote

I'm pretty sure the THX system started in '07, if you look at the press release it was in '06, past the time the 2006 model year started. I don't think they implemented the THX system midway through the 2006 production process...

[edit: Just looked at '06 brochure, did not mention THX certification, but '07 brochure does]

Chris

Very interesting. It amazes me BMW would spend the money they did to do a major freshening in 2006 and then add a completely new stereo system in 2007. I knew they added an Aux-input, but this is a relatively minor addition since the radio always had an aux-in on the back anyway. I always assumed I had the THX system. I guess I don't(and maybe this is for the better...).

[CFoote]

Originally Posted by chickdr

Very interesting. It amazes me BMW would spend the money they did to do a major freshening in 2006 and then add a completely new stereo system in 2007. I knew they added an Aux-input, but this is a relatively minor addition since the radio always had an aux-in on the back anyway. I always assumed I had the THX system. I guess I don't(and maybe this is for the better...).

It's strange man, I'll never understand the Germans I know, for 2 years you'd think they would have left well enough alone...

I haven't heard a THX system for myself, but I've heard the highs are a bit more shrill than the non THX system and that its tough to tune that out since our cars don't have EQ settings like the NAV cars.

FYI, in case you are interested, here are the brochures...

http://www.bmwz4roadster.net/bmw_z4_brochure.htm

Chris

[iPhoneEngineer]

Very informative discussion going on here...more reports are helping build a picture of who has this problem. It seems that most of the people who are disappointed with bass performance ironically have the "best" featured equipment: Navigation and THX certified speakers (Carver subs).

Does the pre-THX premium sound also employ Carver subwoofers? I take it you can have THX speakers without Navigation, but not without DSP?

In my experience with my system, playing from CD has the same problem as AUX. The first time I used the sound system in my car was with a CD, and I was immediately disappointed. I guess I was a fool for not bringing a disc to the dealership and signing a fix into the sales agreement, but I didn't think there would be any problem not easily covered by the warrantee.

Anyway, sorry to disappoint about the testing...but I was unable to compare to my friend's base Roadster, or get to my factory rep appointment today. I had a suspected carcinoma removed from my back and left with 5 sutures, when I wasn't expecting any. It's damn near impossible to drive without stressing the area.

I'll come up with a test procedure this weekend and post results for my car, but it won't be until next month that I can see the factory rep at BMW Mountain View. I'll get in touch with Stevens Creek and see who has the earlier appointment, if I can extract the date from either of them before the turn of the month...

[thekurgan]

Originally Posted by iPhoneEngineer

Very informative discussion going on here...more reports are helping build a picture of who has this problem. It seems that most of the people who are disappointed with bass performance ironically have the "best" featured equipment: Navigation and THX certified speakers (Carver subs).

Does the pre-THX premium sound also employ Carver subwoofers? I take it you can have THX speakers without Navigation, but not without DSP?

In my experience with my system, playing from CD has the same problem as AUX. The first time I used the sound system in my car was with a CD, and I was immediately disappointed. I guess I was a fool for not bringing a disc to the dealership and signing a fix into the sales agreement, but I didn't think there would be any problem not easily covered by the warrantee.

Anyway, sorry to disappoint about the testing...but I was unable to compare to my friend's base Roadster, or get to my factory rep appointment today. I had a suspected carcinoma removed from my back and left with 5 sutures, when I wasn't expecting any. It's damn near impossible to drive without stressing the area.

I'll come up with a test procedure this weekend and post results for my car, but it won't be until next month that I can see the factory rep at BMW Mountain View. I'll get in touch with Stevens Creek and see who has the earlier appointment, if I can extract the date from either of them before the turn of the month...

I believe the non-THX system uses different subs. I had to have a carver sub replaced, and the dealer ordered the wrong one, it did not match, and it wasn't a carver branded sub. Also, I believe you are right about the dsp, for THX, it has to be there, but not looped through the navi unit.

[vicj]

Originally Posted by chickdr

Very interesting. It amazes me BMW would spend the money they did to do a major freshening in 2006 and then add a completely new stereo system in 2007. I knew they added an Aux-input, but this is a relatively minor addition since the radio always had an aux-in on the back anyway. I always assumed I had the THX system. I guess I don't(and maybe this is for the better...).

No no no.....

The THX system is EXACTLY the same for MY 06, 07, and 08....except for the addition of the Aux input in 07. It's all the same people. The Sound system was developed for 06 models, but the CERTIFICATION itself did not come from Lucasfilm until march of 06. That's why it didn't make the 06 manual. The system is the same.

[vicj]

Originally Posted by thekurgan

I believe the non-THX system uses different subs. I had to have a carver sub replaced, and the dealer ordered the wrong one, it did not match, and it wasn't a carver branded sub. Also, I believe you are right about the dsp, for THX, it has to be there, but not looped through the navi unit.

You may have gotten the wrong sub, but the Carver subs are not branded with carver anywhere on them. They were DESIGNED by carver, however, they were built by Philips...and DO have the Philips branding on them. The original woofers you pull out of your car will have part number 65126915841, and woofers after 4/07 will have part number 65139143268. Both the same woofer, just different part numbers. The mystery as to why BMW constantly changes part numbers for the same parts is anybody's guess, but they do it across the board.

One sure giveaway is price...the THX Woofers cost about $217 each, while the subwoofers for the non-THX subwoofers cost about $65. The part numbers for the non THX subs are: 65126915840 to 6/06, 65134167255 from 6/06 to 04/07, and 65139143269 currently.

Another interesting Note, the Current SUBWOOFER part number for the NON-THX system, 65139143269, is the same part as the Mid-bass woofer in the front kickpanel for the THX system. This is why some people believe they get "more" bass from the non THX. It's a much more efficient midbass driver, however, it does not play nearly as low as the THX subwoofer driver. So, the non THX subwoofer plays a little "louder", but it's at a higher frequency. It doesnt "Thump" like a real subwoofer should.

[chickdr]

Originally Posted by vicj

No no no.....

The THX system is EXACTLY the same for MY 06, 07, and 08....except for the addition of the Aux input in 07. It's all the same people. The Sound system was developed for 06 models, but the CERTIFICATION itself did not come from Lucasfilm until march of 06. That's why it didn't make the 06 manual. The system is the same.

Glad you cleared that up. What you said makes a lot more sense to me. As an aside, where are the carver subs? Behind the seats? I thought they were in the front kick panels as I don't really feel any significant air movement coming from the lower drivers behind the setas.

[vicj]

Yes, they are behind the seats, behind that rectangular pop off grill. You "hear" the front more, because they are playing midbass frequencies, which you can "hear" more clearly. The subwoofer frequencies are more about "feel". They are not large subwoofers, and will not move a lot of air when doing the "hand test" to feel for moving air. To work in the enclosures provided, they have a VERY stiff compliance, and a very low Xmax. They just aren't designed to move tons of air.

However, I have done a very simple test and felt firsthand how effective they can be. I just took them out and drove the car around for a couple days. It becomes very clear immediately how much the subs contribute when you do that. there's still plenty of midbass from up front, but it just isn't anchored like it should be at the bottom end. Remember, these aren't large, 4-ohm subs, like most aftermarket applications. They are 6.5 inch, 10-ohm subs. 100 watts into a 10-ohm load is not going to knock anyone's socks off in a listening test.

So, could they be better? Perhaps. A larger sub that won't be choked off by the tiny enclosure, with a lot more power may work out, and that's what I'm going to do. The risk is that the enclosure size may cut off the bottom frequencies somewhat in a larger sub, and I may be better off with the 6.5. we'll see....

[CFoote]

Originally Posted by vicj

No no no.....

The THX system is EXACTLY the same for MY 06, 07, and 08....except for the addition of the Aux input in 07. It's all the same people. The Sound system was developed for 06 models, but the CERTIFICATION itself did not come from Lucasfilm until march of 06. That's why it didn't make the 06 manual. The system is the same.

I stand corrected then, as I thought that this would be something BMW would have advertised/bragged about in 2006 when the facelift/refresh happened. Maybe Lucas/THX dragged their feet on getting the certification done.

BMWs parts system definitely makes it harder to figure out when things changed. As you mentioned, the part numbers constantly change and its nearly impossible to figure out the reasoning behind that.

Chris

[MrTomas]

fwiw, I have found this MP3 to be usefull and enlightening:

http://sinan.ussakli.net/basstest/5-100.mp3

With DSP off, I hear my Carver subs cut in at about 4 sec. They rise to a max from 11-13 secs and trail out at about 20 secs. Then cut back in around 34 secs, hit the max from 47-49 secs, and trail off again at 56 secs.

You can hear the front mid-base speakers cover the range from around 20-40 seconds give or take.

If you put the DSP on for this track, you can hear some interesting loudness/volume effects.

[iPhoneEngineer]

Well, I finally got the testing done last week, but have been totally swamped since. The results imply that the poor performance I notice is probably due to the front "midbass" speakers rather than the Carver subs.

It seems that 65-130Hz is the weakest range. In fact, around 68Hz, my test showed only about 3dB difference to background noise...compared to over 30dB at around 200Hz.

I used an iPhone 3Gs with "SPL Meter" (free) to measure, and its readings correlated well with my ear's perception, so I think the microphone is relatively balanced. However, the microphone on the camera automatically adjusts sensitivity for different volumes, so pay attention to the screens only.

The tones were generated with "AudioSigGen" (free), through the Aux input, with the stereo on volume level 4 (four presses of the steering wheel volume up after turning it down completely).

Let me know what you guys think of this result, and if anyone can repeat it!

http://web.me.com/goodsonscott/video...%20Testing.m4v

[Diokaef]

Interesting is that the system on my 08 is totally different from my other 08 (sold) even the radio buttons are different then any other MC that I ever saw, the car sound is incredibly better then the other one as well and I have the NAV, also I did a side by side with another M few months back and mine is louder. I really don't know why tho but I know that I never saw a M with that type radio.

The buttons on mine have a aluminum ring on them and also 2 more buttons with this symbol on it (-)

[r4gs]

Originally Posted by Diokaef

Interesting is that the system on my 08 is totally different from my other 08 (sold) even the radio buttons are different then any other MC that I ever saw, the car sound is incredibly better then the other one as well and I have the NAV, also I did a side by side with another M few months back and mine is louder. I really don't know why tho but I know that I never saw a M with that type radio.

The buttons on mine have a aluminum ring on them and also 2 more buttons with this symbol on it (-)

mind showing us a photograph?

as for sound quality, i stated in a separate thread that radio playback quality is poor in comparison with playback from an audio or mp3 cd. the difference is marked and i actually think, after listening to high quality recordings on an audio cd, that the sound system is among the best i've heard. this is in comparison with bang & olufsen systems in mercedes, the bowers and wilkins systems in jaguars and the bose that are in so many cars nowadays.

[Diokaef]

Yes give me a few days and I will post some pictures up.

[vicj]

Originally Posted by iPhoneEngineer

Well, I finally got the testing done last week, but have been totally swamped since. The results imply that the poor performance I notice is probably due to the front "midbass" speakers rather than the Carver subs.

It seems that 65-130Hz is the weakest range. In fact, around 68Hz, my test showed only about 3dB difference to background noise...compared to over 30dB at around 200Hz.

I used an iPhone 3Gs with "SPL Meter" (free) to measure, and its readings correlated well with my ear's perception, so I think the microphone is relatively balanced. However, the microphone on the camera automatically adjusts sensitivity for different volumes, so pay attention to the screens only.

The tones were generated with "AudioSigGen" (free), through the Aux input, with the stereo on volume level 4 (four presses of the steering wheel volume up after turning it down completely).

Let me know what you guys think of this result, and if anyone can repeat it!

http://web.me.com/goodsonscott/video...%20Testing.m4v

Ay yi yi...testing with an Iphone, with a cheap free Pink Noise through the Aux jack, and you expect ACCURATE results??
My bass has a smooth roll off, from a -3DB point of about 65HZ, down to -6DB at 40HZ. Pretty standard for a small sub in a small, sealed enclosure.

My test was done using an IASCCA Gold CD with a 1 minute Pink Noise loop recorded at 80db at Scheffield laboratory, an Audiocontrol SA-3055 Real Time spectrum Analyzer with a professionally calibrated microphone. Audio Volume was calibrated to exactly 80db before testing.

The free phone widget SPL Meter I downloaded to my Droid showed a 20db increase at 40HZ when I simply spoke into it. Total garbage.

[MHeavNC]

I find my Carver system to be very interesting... Lady Gaga sounds great, but Van Halen sounds like crap!! WTF?

[Diokaef]

Originally Posted by r4gs

mind showing us a photograph?

as for sound quality, i stated in a separate thread that radio playback quality is poor in comparison with playback from an audio or mp3 cd. the difference is marked and i actually think, after listening to high quality recordings on an audio cd, that the sound system is among the best i've heard. this is in comparison with bang & olufsen systems in mercedes, the bowers and wilkins systems in jaguars and the bose that are in so many cars nowadays.

Here, this is mine.

[r4gs]

^ i don't have nav and can't compare my head unit with urs, but i definitely do not have aluminum-trimmed control knobs. diokaef, is urs among the last production m's built?

[Diokaef]

Originally Posted by r4gs

^ i don't have nav and can't compare my head unit with urs, but i definitely do not have aluminum-trimmed control knobs. diokaef, is urs among the last production m's built?

Yes I think so. it's a 08, I got it new on 09.

[Diokaef]

I know that the pictures don't show well but is kind like chrome finish or polished aluminum.