Bit Ten Install and Tuning

pentoncm · January 2012

Now we just need some basic headunits with optical out. They've got to come if there are going to be this many processors on the market with digital in. Alpine is going the other way, I feel as though their prices go up but they are offering less. They are focusing too much on Pandora and multimedia apps than the music.

All in all what is happening is really good for the SQ market with all the competition. The bit one came out and revolutionized processors and it has been a big hit. Now these new processors are taking the next step all pushing each other to make the best product. I have read that Audison is developing a new version of the Bit One (no details on release) but all of this will drive a better processor in the end. It would be nice if their DRC could tune in the future like the ARC and Alpine processors.

arun1963 · January 2012

pentoncm wrote: »

what the heck is a Bessel Crossover?

The long of it goes over my head, but the short end is that, it's similar to the LR filter but causes less phase shift around the xover point.

arun1963 · January 2012

Yeah, the one drawback with the bit series is that you can't tweak on the go. Was spoiled for that with the pio

MacLeod · January 2012

It does look like some good things are heading our way. There was a time where there were some pretty slim pickings for processors. I guess nobody wanted to spend nearly $1000 on one. I dont understand why they have to be so expensive. I can see $400-500 but this $700-1000 is ridiculous. I guess youre probably paying for R&D mostly.

I do like the idea of being able to tune via a laptop. I love tinkering around with computers so that would be fun but having my H700 remote right there all the time is very nice. I could tune at red lights or out in the parking lot after work. Would have to get used to giving that up.

The H800 looks to be cool but its godawful expensive and Ive heard a lot of complaints about noise with it. Dont know why Alpine cant make a processor that isnt riddled with noise issues.

I hope if Pioneer comes out with a new processor that they make their time alignment in MS and not inches for God's sake. That was so annoying to work with.

arun1963 · January 2012

On the bit10 we TA using both inches and ms. You set the distance in inches and then fine tune in steps of 0.2ms. I fine with it really, cause at the end of the day you're doing it by ear. I agree that the processors should be cheaper. I guess if more people knew how to tune there would be a greater demand and prices would come down.

You should open a tuning school Mac. $300 for a 1 week course :biggrin:

MacLeod · January 2012

Nobody would pay. Who wants to pay for tuning lessons from somebody that cant win a championship in 5 tries! :biggrin:

arun1963 · January 2012

The champions seem to be high strung and closed individuals. We would rather have you the way you are, thanks. At least this way you've still got the fire burning. If you'd won a couple, the challenge would be gone and you wouldn't know what to do with yourself :razz:. The guys who know you from the lanes, know your tuning skills. I've heard it from more than a couple.

arun1963 · January 2012

I'm really frustrated. I have this brassy vocal thing going, which is bugging the hell out of me. It seems like I've tried everything. Cut the 3-4khz range. then tried the 600-1.6 rznge, played around with the balance between 2-2.5khz and even tried to mask it out by adding a touch of fatness in the 250-400 range. Everything works to different degrees but no permanent resolution.

Everything apart from this sound nice. I need to get over this issue in order to focus on the other areas and see what can be tweaked there. I think maybe it's just the effect of reflection. I'm going to cover the dash with a think towel and see if that helps in solving it. At least I'll know one way or the other. It's this gratey texture in the vocals that sound stretched. It could also be how the mids and tweets are blending in the 1 octave around the xover point.

Maybe I just need to step away from this insanity, for a bit:biggrin:. Any ideas?

pentoncm · January 2012

OK lets break it down.

(1) which driver is the vocal thing coming from? Both sides? Is it the mids or the tweets?
(2) Besides vocals is there an instrument that jumps out at you? I'm wondering if there is an issue somewhere in the 1.2 to 2.5kHz region.

pentoncm · January 2012

arun1963 wrote: »

I'm really frustrated. I have this brassy vocal thing going, which is bugging the hell out of me. It seems like I've tried everything. Cut the 3-4khz range. then tried the 600-1.6 rznge, played around with the balance between 2-2.5khz and even tried to mask it out by adding a touch of fatness in the 250-400 range. Everything works to different degrees but no permanent resolution.

I have some suggestions for you :
(1) Try cutting 800Hz more on the far side, I have near -4.8, far -6
(2)1.25kHz, I have near -4.8db, far .5.5
(3) 1.6kHz I have near -5db, -5.5
(4) 2kHz I have near -3.5, far -5.5
(5) 2.5kHz I have -4, far -5.3
I would also suggest that you raise your 250Hz to 400Hz levels on the far mid. Mine are in the -2db area there.

I know we have our xovers set differently, I'm at 4kHz.

arun1963 · January 2012

pentoncm · January 2012

I have a question for you guys. I've been looking around the DIYmobile forums at different people's opinions of where center should be. Many are very stubborn and have absolute views about what is correct.

I see that you have two general options each with their own disadvantage.

(1) Center in the middle of dash. This causes equal stage width but at the expense of accuracy. The location of notes will not match up with a 2.1 or headphone comparison. In this case you will not hear notes from 2 feet to your left side out of the car.

(2) Center in front of driver. This is how I have it set in my car. I do it this way because it is my preference to hear vocalists in front of me. Also, I like hearing instruments on the far right and far left. Example, I can hear cymbal crashes beyond the left mirror move in front and then move to my far right. I find this more enjoyable. I agree that here there is compression on the left side, but it is not something terrible.

I see each as a compromise. I see no absolute right, each has trade offs associated. Do you want even stage width? Or would you rather have a slightly compressed left side, but that could be considered more accurate regarding location of instruments? With a stage centered middle of dash, won't the stage only go as far the physical driver such as pillar or door. In my car my stage extends beyond my left mirror which I prefer.

arun1963 · January 2012

I am fussed about close to equal width on both sides. Not only width, but equal mass as well. In most cases the vocalist is recorded at centre stage. I used to place the vocalist around the rear view mirror. With this configuration my width was just beyond my A pillars on both sides.

Then Mac made a point in post 56, where he mentioned the placement of vocals should be off set slightly to the right of the rear view (for you'll sitting on the left). I tried this and now the vocalist is just beyond the left edge of the rear view (I sit on the right). A couple of things that I noted:

1. For some reason, the overall tonality is much better. I had some tonality issues that I could never cure with the centre stage at the rear view. I have no clue why it happened.

2. You have to watch the mass of the near side stage very closely, else you can quickly get to a point where the far side has great definition and weight, but the near side feels empty.

3. By moving the centre stage I lost a bit of width on my near side. The width of the stage remains the same except the whole thing is shifted slightly to the far side.

Taking this idea from one of the posts on diyma.

X = edge of stage
P = Pillars
C = Centre stage
@ = where you're sitting

This is how I had it earlier:

X--P

C

P--X

This is how I have it now:
X---P----C

P-X

I achieved this by going back and balancing for L/R a touch to the left of where I would earlier. That plus a little tweak on delays. Based on your description, this is how you have it:

X--P--C----X----P

Chances are if your centre is right in front of you, you may not have much width on the far side. I would definately not want the centre in front of me cause that means a squished stage and loss of accuracy. I'm curious about how Mac see's this and what his ideal stage would look like.

pentoncm · January 2012

My stage goes from just a teeny bit left of my left side mirror and over to my right pillar. I have very good stage width but it is asymmetric. The downside to this setup is that the left is compressed as compared to the right.

Theoretical question, would my left side be less compressed if my mids were in kick panels?

arun1963 · January 2012

Kicks panels are good for depth. You would actually lose a bit of width (vs doors) unless you vented the mids in the kick panels. Where you place your vocals, is purely related to where you balance L/R for each frequency and how you set the TA.

pentoncm · January 2012

How do you guys have the SPL meter when measuring. Point it at the drivers? Hold it forward? I go for a Center in front of me but I was holding the SPL meter where my left ear would be for left side measurements, and then I would hold it near the right ear for right side measurements? Should I hold it more in the center?

MacLeod · January 2012

I lean back as far as I can and place it about where my head would usually be and point it slightly towards the direction of the speaker playing the test tone. Its not a super great mic so it wont have the same off axis measuring capability that your ears do and turning it slightly towards the speaker will help get a more accurate reading.

Remember, reflections wont be measured so let your ears be the final judge. If the SPL meter says that 800Hz is 6db hotter on the left side but it sounds the same to you, leave it. Your ears and brain are a far more reliable source than some $50 SPL meter from Radio Shack.

arun1963 · January 2012

I normally do this sitting in the back seat and then hold the meter about where my head would be. I like Macs idea on angling the meter towards the driver thats being measured. Will try it next time I do the sweep.

Once I've done the neasuring and balancing, I will go back and play the tones just to make sure they all align roughly in the same vertical plane. I'll do the 1.6-5khz range playing both the mids and tweets. If say at 3khz the mids image up high but the sound also pulls a bit towards one of the tweets then I'll cut that side on the tweet a bit or play a bit with the delay (whichever works better) to get both sets of drivers to deliver a point source image.

MacLeod · January 2012

Ya don't want to sit in the back seat because your body and especially your legs, will alter the output of some frequencies. That's why you have to do all your tuning and measuring while you're sitting in the front seat so you can take all that into account. Its especially important when you take up a lot of space because yore fat like me.

arun1963 · January 2012

*Facepalm*, no bloody wonder how it measured, was never how it sounded the best. To the point, where I just put the damn thing away. The first few times I did it sitting in the front seat, till I had this brain wave. Yeah, I'm tall and fat so yes I do take up a ton of space. But even the times I did it in the front seat, the readings for the 1-4khz range were almost always screwed up. Not so much for L/R balance but for overall intensity. I am quite sure the ear perceives this range louder than what it measures, due to reflections. You mentioned this as well.

For a technical idiot like me, it's actually easier to do the L/R balance looking at the image and listening to tonality. I've finally got astable image and decent tonality. Music sounds good.

Mac, can you back up to post 104 on the width thingy and describe what your ideal stage width would be?

MacLeod · January 2012

Ideal stage width is outside the car. That's hard to do and requires some serious trial and error in speaker placement. Mark Eldridge's NASCAR is the one that does it the best but its literally a sound system with a car built around it so it kinda doesn't count IMO.

With the mids in the doors, if they're low and forward enough, it can work decently with a tweeter up high. The door speaker is usually outside the A pillar so your brain hears it outside the A pillar but since your brain is also telling you the sound is coming from the tweeter in the pillar, it splits the difference and so it can sound like its just outside the A pillar. This trick usually doesn't work on the far side setup that much because you're hearing it directly on axis almost so your brain doesn't have to do as much interpretation as it does with the off axis, near side speakers. But basically you're not going to get width outside the A pillars without actually having a speaker that is physically outside the pillar.

pentoncm · January 2012

I have a question about time aligning tweeters to the mids. My mids are in the door and the tweeters are about 3 inches away. Right side tweeter is three inches to the right of the driver woofer, left tweeter three inches to the left of passenger woofer.

I have played with added delay to the tweeters to raise the stage. There is a point on the driver side where there is .5ms delay (compared to woofer) where it sounds like the tweeter is at the edge of my driver side mirror. Although this sounds good like this, is this trick tonally accurate. Is the tweeter out of acoustical phase? Also this trick doesn't work on the passenger side. I can only get the tweeter to line up with the woofer. Also playing around with the delay of the tweeters does affect the tonality of the system. At some points it sounds like the tweeters are brighter and the midbass is lower, others when the midbass stands out more and the tweeters are more laid back. When the tweeters are brighter is this because the woofers and tweeters are more in phase with each other?

I am planning this week on going through a range of delay setting times and measuring 4kHz (xover point) when the tweeter and woofer are playing. I should be able to find when they are in phase by finding what delay setting gives me the highest intensity at the xover point right?

Any thoughts guys, thanks.

arun1963 · January 2012

If you're playing the mid and tweet on the far side, the drivers would be in acoustic phase when you hear them as one point source. The very low end will still drag a bit towards the mid. But yes you want the majority of sound from one point preferably higher than the physical level of the driver. Mounting the tweet physically higher helps in pulling up the image higher.

It's tougher to achieve this on the near side because a) the drivers are physically closer to you and b) because they are much more off axis than those on the far side. You have to watch the lower end FR on the near side lighten it up a bit to float the image higher on the near side.

I'm a great believer in setting the TA two drivers at a time. The sub and the far mid, then the two mids, next the mid and tweet on one side then the other and lastly the two tweets together. Then playing all drivers and integrating everything with a bit of tweaking.

arun1963 · January 2012

pentoncm wrote: »

I am planning this week on going through a range of delay setting times and measuring 4kHz (xover point) when the tweeter and woofer are playing. I should be able to find when they are in phase by finding what delay setting gives me the highest intensity at the xover point right?

If 4khz is your xover point thenplay only the mids and get L/R balanced. Then do this playing tweets only. Get them imaging up in the same vertical plane. Now play both sets of drivers together. If the image remains in one place they are in phase. If one set of driver images up where you set it and the other pulls towards the speaker then you need to tweak the TA a bit. Not sure if that made any sense :biggrin:

arun1963 · February 2012

I've been playing around a bit with the axis on the drivers. My tweets are on the dash and were firing at ~ the opposite B pillars. Or at least at that edge of the headrest. I always had issues with the near tweet, it was too on axis and the early reflections off the dash/windshield never let me get the top right quadrant on the image right. A fair bit of the highs on the right side dragged to wards the tweeter.

I turned both tweets more off axis. So that now they're firing at a point about 6" ahead of the B pillars, on the side windows. Almost immediately the issue with the right tweeter was better. The 2-5khz range was not as loud, hence easier L/R balance. Although by getting them to fire across the dash I'm actually adding to the amt of reflections, but due to the longer pathlengths they are more delayed and hence less in your phase. TA seems to work much better. Over all, better tonality and depth. Added per ception of depth was a big bonus.

I spent the first few days tuning as also checking to see if any major problems crept up, ones that I may have missed in my initial euphoria. All seems good so far. The sound is much better. Overall I cut my 1.6-4khz range a bit as well and opened up 10+ a bit more. I have'nt felt the need to tweak for last day or so. One thing I think I'll need to do a bit is to make the sound a bit more dynamic, maybe paly around a bit with the two ranges, but its not so bad for now.

Oh!! and I measured the FR of how it sits and I came up with a curve that is quite close to the FM curves I posted earlier. Of course it's not as smooth as that curve but the flow is fairly simmilar. I found that really interesting. Shared the findings on diyma and got slammed by the RTA flat crowd. Got one confirmation and nod from AW :biggrin:.

pentoncm · February 2012

Yeah I saw that on DIY. There are some stubborn people over there. I like it over here where people are still willing to learn.

The flat response is total crap. One person had posted that the engineer or producer would have recorded the signal flat so you should play the signal with a flat eq. This is completely wrong and they don't know anything about how albums are recorded. Albums are not recorded flat.

Dare I go into this again? If we are supposed to listen to drivers with a flat response therefore every high end headphone manufacturer would aim for a flat response. You can go check the response of almost any headphone over at headphone.com. None are flat.

I just don't understand the argument. Go flatten the response in your system so that 60Hz is at the same intensity as 1kHz and having everything flat. Are you going to bet money that when the kick drum hits that it sounds like there is a drum in your car? Its going to sound like crap. I guess then the flat EQ people will then tell you that real drums aren't accurate and that their car is the true reference. :idea:

pentoncm · February 2012

For instance in rock music, electric guitar is equalized post recording to achieve a specific sound. This is widely known, big example being what happend to Nevermind back in the day. Butch Vig equalized the guitar parts making it sound fuzzy by changing the frequency response which ticked Cobain off.

Even if a producer/engineer recorded an album so that every frequency was perfectly 'flat' that would be based off of his opinion and his gear. His studio monitors would have a specific response and the room would alter the sound. If he is using headphones, those are colored.

pentoncm · February 2012

I have some new EQ settings to post after trying my best to L/R balance with the SPL meter. I think I have phase of the tweeters under control. Have any of you tried getting the tweeters in phase by using pink noise. I listened to 4kHz pink noise that I L/R matched and then messed with the delay. You can hear it move really easy and tell when the tweeters are in and out of phase with each other.

arun1963 · February 2012

pentoncm wrote: »

I have some new EQ settings to post after trying my best to L/R balance with the SPL meter. I think I have phase of the tweeters under control. Have any of you tried getting the tweeters in phase by using pink noise. I listened to 4kHz pink noise that I L/R matched and then messed with the delay. You can hear it move really easy and tell when the tweeters are in and out of phase with each other.

arun1963 wrote: »

If 4khz is your xover point then play only the mids and get L/R balanced. Then do this playing tweets only. Get both sets of drivers imaging up in the same vertical plane. Now play both sets of drivers together. If the image remains in one place they are in phase. If one set of driver images up where you set it and the other pulls towards the speaker then you need to tweak the TA a bit. Not sure if that made any sense :biggrin:

Did you try what I suggested? Did it work?

arun1963 · February 2012

Typically, the max phase shift will occur at the xover point. However phase will vary with frequency and amplitude. So once you get the mids and tweets in phase at 4khz, do check the phase coherence at 3 and 5khz as well.

Bit Ten Install and Tuning

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