discussion Sound deadening the car. And a few audio upgrades.

[lowfat]

Are the right speakers louder or quieter? I can see them being slightly louder by default so that the driver's seat is the optimum listening spot.

Do none of your control devices have any kind of balance option?

All the right speakers are louder. Which IMO is just wrong. Your legs are blocking a lot of directional sound from the driver door speaker. So you end up hearing nothing at all from that speaker in this setup.

I had looked in to using the DSPs briefly. Thought it seemed difficult. But taking another look maybe I can do it. Not sure how I can get them exact but I'll give it a shot.

Hmm. Actually might be difficult. When using the DSPs to set delay and frequency curve corrections I bypass the infotainment and go straight to the amps. I guess I'll have to try hooking up the laptop via bluetooth and hopefully it is high enough quality where I can use it. I have my doubts tho.

EDIT: Guess I shouldn't be bypassing the infotainement during the DSP config anyways. As most infotainment does some sort of EQ, which would be applied outside of my correction.

 

[lowfat]

Did have a lot of issues yesterday trying to tune. Had issues w/ the amp where 1 channel just wouldn't work. Zero output. Tried every test I could think of. Eventually just toggled the switch from 5 channel to 3 channel mode and back. And it started working. Rather hope that doesn't happen again as the amp is under a seat lol.

Anyways I did manage to get the channels equal level. Was pretty damn easy TBH. I changed 1 DSP to left channel the other to right. Then assigned one of the onboard pots to be used as a gain. Played a test tone then just matched the voltages.

First I am just doing alignment w/ the dash speakers. Red line is the right speaker, which is always first as its the furthest away from listening position. Then green is when both are played. You can see there are a couple peaks that have turned in to valleys. This is caused by wave cancellation caused by the speakers not being equal distance to listening position. So delaying the driver side speaker you can get the audio to arrive at the same time, lessening the wave cancellation.


And this is after applying a 1.15ms delay to the driver side speaker. Damn near perfect. Using a USB mic does add a bit of error due to clock drift caused by the computer itself. But I am really happy. Ignore all the numbers before 400Hz. The speakers are crossed over from 500-6000Hz so anything below that doesn't matter.


Will be doing a lot more today hopefully.

 

[lowfat]

The car gets about 3 hours of it being off testing audio before the battery dies.

The laptop got around 4 - 4.5 hours of battery, which ain't too bad.

But I spent almost all day out there attempting to tune. I do believe I am finally getting it. I believe I have the speakers time aligned. It still doesn't sound right to me. But hopefully after the EQ is applied things sound better.

I have finally figured out how to export the measurement curve and how to edit the file so I can add it to SigmaStudio. EQing the dash speakers first. Then once they are done, I'll take a measurement with both the dash + door speaker playing. Then EQ the door speakers to compensate for the frequencies the dash speakers are playing.


Blue line is the frequency response taken in the car. The red is the projected response after it applies the EQ.


Back to work tomorrow. But now that all the equipment is installed it shouldn't take long to apply the EQ and test.

 

[lowfat]

Did make a lot of progress tonight after work.

Dash speakers before EQ.

And then after EQ. They are about 5dB quieter than before so I'll have to turn up the gain a bit. But pretty smooth curve. The slight downward slope is intended.


The right hand speaker. The light green is after EQ. Besides highs this speaker didn't require much.

And the left speaker. This one is hard to correct. I put a couple of 2x6s where my legs would be
. Purple is before. Green is after EQ. And red is both L+R channels. The dip @ 400Hz has to be phase cancellation as just the left speaker alone doesn't exhibit the issue. Not sure I can fix this anyway. The dip @ 900Hz may be fixable.


But the bigger issue is I still feel like the right side is louder. Even tho I measured w/ a multimeter. At the very least the highs are a lot more noticeable. Tomorrow I'll have to take a bunch more measurements of everything and probably consult w/ the pros in the FB group.


As like all my 'hobbies' this is so much more work than I expected.

 

[lowfat]

Spent 3 hours in the car last night and an hour before work this morning. I am having one hell of a time trying to get it to sound good. They are just overly bright and fatiguing. I like the speakers in my house so I decided to measure them.

The Paradigm SE11 MK3 + a tiny Klipsch sub that I use on my PC. Overall I love these speakers. I knew the tweeters weren't very good but they are pretty terrible. I plan to rebuild cabinets for these. Will definitely will be going w/ better tweeters when that happens.


And the B&W DM602s I bought a month ago. I love these. And the frequency curve is pretty flat. So why does the car sound so harsh. Hmm....

 

[lowfat]

I thought I had everything aligned. When you play the same audio out of both speakers it should be 6dB higher, which is twice as loud. Obviously in a perfect world, which car audio isn't. When the combined output is lower than the other 2 its wave cancellation. I asked the experts what is going on here and they believe the speakers aren't time aligned perfectly.



So I spent a few hours trying to adjust the delays and try different settings. But my measurements are never exact. I thought the issue was the USB mic I was using. Since the way it tests for delay is by playing a chirp from the furthest speaker before and after every measurement. Then it it has a reference to compare the other speaker against. I thought this just added inaccuracies.

So I did repeated runs back to back. Here is the left speaker. 99.9% the same over 3 runs. I did it 4 just previously and all 4 were the same.


But then the right side. All 3 runs are different. They are ranging up to .045ms in just my 3 tests. And since my reference speaker is on the right, all my measurements are likely off.



I am using 2 separate DSPs, one for each channel. I do have 2 others I can swap in to see if I can get stable results or no. Maybe I'll have to swap in the more expensive DSP I have on order as it is more powerful and can do 8 outputs, which is enough for everything. Would suck tho as I need that one for my noise cancellation speaker project.

 

[lowfat]

So I did swap out that DSP. Not sure it was actually an issue or not. What I ended up doing was just multiple measurements back to back. Then as long as 2 were identical I deleted any outlier. Finished up alignment.

Then finally hooked up the sub. At first I was having some issues. No sound. Checked for AC voltage on the sub out on amp. Nothing. Started fiddling w/ switches and crap on amp and did get voltage out. But I also smelt faint burning electronics on the amp. Hmm. But it seems to be working so I hooked the sub back up. Working. Spent the next couple hours EQing. I do have that dip around 400Hz. It isn't caused by alignment as originally was thought. It seems it is the stock HU has a phase correction for the stock speakers. Not sure if I can correct for it yet. Anyways I took it out for a short drive and I absolutely love it. It sounds fantastic. I still have feel as if the right side is louder a tad and I'm not exactly sure why. I also still need to correct the delays for everything to account for the sub. Which shouldn't be too hard. I'm sure everyone is sick of all my graphs. Hopefully I can start cleaning up the interior and putting it back together shortly.

 

[djbrad]

Love the graphs, I'm learning that you can calibrate audio a lot!

You don't understand a job until you see all the work done.

The winning line is near!

 

[Shadowmeph]

My Lexus has a fair amount of road noise but I am not sure I would go to those lengths to quieten it up well maybe if I was like 30yrs old or younger hehe mind you it would help allot when listening to the stereo but then I only listen to the news so I don't think that it matters that much . dont get me wrong the sound system, in this old car is very good I have tried it out it sound great but like mentioned the road noise is a little loud so need to crank it up to hear everything clear when moving down the road I tested out my cars sound system using classical music which many different tones but again I didnt use any software just used my ears

 

[lowfat]

The sound deadening was 100% worth the hassle. And TBH I should have just stopped there.


The audio tho.... Always 1 step forward 1 step back. I thought I was happy w/ the sound but I'm not. Some music sounds great, other music just doesn't. So I go about doing more tuning. Something ain't right w/ the sub.

It should be mostly like this. But an increase in 20-40Hz due to the 'cabin gain' in the car.


But what I get is this. From 50-100Hz it should be flat not this massive rollercoaster. A 15dB natural drop makes no sense to me.


*sigh*