Bit Ten Install and Tuning

pentoncm

I've tried having my near mids delayed by between 3.25 and 4ms, and far mids 2 to 2.92ms. In all cases it sounds better when I invert the phase of the sub. I had been hesitant to add even more delay, I'll go and try adding even more and see how it sounds.

arun1963

Where is the sub placed and which way is it facing? How is the eq set for the 20-80hz range?

Can you describe 'sounds better' a bit?

arun1963

Check the polarity of connection from your amp to the sub. If the polarity is reversed (+ from amp connected to - at sub), then reversing the phase will actually bring the sub back in phase. I'm just trying to eliminate all possible options.

pentoncm

Polarity is good, positive going to positive and vice versa. There is no phase switch on the amp. Sub is in the back corner on driver side, side firing towards the opposite side of the car. Also the rear seat is always down on the passenger side to make sub more efficient and cool my 4 channel amp. I've tried different positions before and this position was the best. I don't like the sound of the sub against the seat and firing back - it sounds empty, and in the corner and firing rear is too boomy. Subsonic is turned all the way down to 5 Hz.

If I don't reverse the phase, kick drum sounds weak. Upper bass sounds good but there is no low end impact. Kick drum sounds up front but low end is just missing. Inverted phase on bit ten, there is much more low end energy and it is up front. Here it sounds like the sub and mids are cooperating in the crossover region smoothly. Without phase reversal it sounds like the sub is not doing as nearly as much.

Can some amps cause the signal to undergo a phase shift compared to the full range amps?

EQ is flat up until 60Hz (-1.5db), 80Hz (-7.5db), 100Hz (-9db).

arun1963

Its possible that your issue is not phase related, but one of integration between your sub and mid bass. You have the spl meter right?

Measure the 20-160hz range using the pink noise and the spl meter.

1. Sub only
2. Both mids only
3. Sub and mid playing together.

Dial in your TA before you do this. Let's see what comes up.

MacLeod

Dont be skurred to add more delay. I have my driver side tweeters delayed by 6.5 ms. It aint gonna hurt anything. If it doesnt sound good, you can switch it back.

arun1963

Wow I've never gone out that far. What's the delay on the near side midbass and mid range?

MacLeod

Mids are about the same IIRC cause theyre right next to the tweeters. The mids are the furthest forward driver in my system. Theyre in A pillars while the tweeters are in the sail panels about 4" behind the mids so I was able to keep their delay about the same value.

arun1963

One of the continuing challenges for me, is overcoming mindsets and stepping out of the comfort zone. On these settings I have pulled up the 80-200 hz a bit but the biggest change is in the 2-5khz at the near mid and tweet. This range is now pulled up ~1.5-2.5 db on the near side mid and cut by about 2-2.5db on the near tweet. This range is now dominant from the mid. The way I had it setup earlier, I think the tweets carried a lot more. The touch of hollowness on vocals is gone and the upper mids are much more fluid. Not tight and a bit harsh like earlier.

pentoncm

I haven't had the time to go through and do the measurements with my SPL meter. I did go through quickly and play with delay and phase. So I tried increasing the delay even up to 6ms. Through the entire range from 3.5ms to 6ms it sounds better when the phase is inverted. The 3.8 to 4 ms range sounds optimal to me right now, adding more delay sounds like there is less bass.

I am thinking that even though the wires from the box to the amp are in phase, I might have hooked up the actual sub inside in reverse order in the box (+ side of voice coils going to - terminal on the box). When I had the ported db sub in I had played with reversing the phase but it made it sound worse, like there was less bass and it moved it to the rear (in the same 3.5ms to 4ms region). Now with my new sub it is the opposite, revering phase makes the kick drum sound much deeper and realistic sounding, and it just sounds like there is more bass. Basically it sounds like the sub and mids are cooperating with sub reversed while in phase it is mostly the mids.

MacLeod

Well if thats what it takes to make it work best, then thats the answer. At the end of the day, its your ears that matter and if thats what sounds best then thats the way it should be. If you get more bass output with the phase switched then that is the correct phase. If you lose bass energy then youre getting cancellation and that means the phasing is incorrect.

arun1963

Most people who are serious tweakers will eventually realize, that there is a huge subjective side to sound, beyond the numbers. Once you accept that, it opens up a whole Pandora's box in terms of what is legit and what is purely your ears and mind playing tricks on you. This is a partial list of some of my observations. I wonder how many are true and how many are myths.

1. The same setting will sound different with and without a passenger upfront. With a passenger up front you will lose a bit of the lower end.

2. Engine, road and wind noise will obviously lead to cancellations and hence change in sound. Even the airflow from your a/c or heater will interfere with the sound dispersion and you will hear that difference.

3. On cold winter days / nights you will feel a loss of the lower end, till the cabin heats up.

4. Sound in a car is mostly about trade offs. In most cases you will get something at the cost of something else.

5. Some days are just better hearing days than others.

6. Knowing when to stop and save the settings is critical.

7. Once you get to a decent level, its easy to develop mindsets and tweak within a narrow band. That will limit your progress.

6 was always a weakness, 7 is something I'm discovering recently. I had made a list of 16 points for this post, but I think I'll start with these. Would rather be ripped on 4 of 6 than 12 of 16 :biggrin:

pentoncm

Totally agree with the winter day thing. I first noticed it like 7 years ago ,even with stock systems and no sub it sounds like there is less low end. The question is is there really less bass because some components need to warm up or is our perception of bass reduced when we are colder or the air is colder that the sound is travelling through?

MacLeod

arun1963 wrote: »

1. The same setting will sound different with and without a passenger upfront. With a passenger up front you will lose a bit of the lower end.

Itll depend on where the speakers are located. If theyre in the kick panels or in the doors, then a passenger will block their line of fire and youll generally mainly get a center image shift to the left. Dont think Ive ever noticed less low end. Dont think that would make a difference. If anything it would increase it as there isnt as much empty space in the car with a passenger in there.

2. Engine, road and wind noise will obviously lead to cancellations and hence change in sound. Even the airflow from your a/c or heater will interfere with the sound dispersion and you will hear that difference.

Wont interfere necessarily, just drown it out. The AC wont matter much at all unless youve got it blasting on high. Road noise will easily mask all the intricate details that you were up all last night trying to tune in.

3. On cold winter days / nights you will feel a loss of the lower end, till the cabin heats up.

Hmmm, not sure about this one. I would think this might just be from youre freezing your **** off and cant feel as good as in warmer temps.

4. Sound in a car is mostly about trade offs. In most cases you will get something at the cost of something else.

Nah. You can get as much as you want but itll depend on how far youre willing to go with the installation. Tuning will only get you so far. A car with stock speaker locations just doesnt have the same potential as a car with a much more custom installation as in mids in the kicks in sealed enclosures.

5. Some days are just better hearing days than others.

Aint that the truth. Some days I think everything sounds like a dying cat then the next day its not so bad.

6. Knowing when to stop and save the settings is critical.

Its all a work in progress. You stop tonight because your ears are fried and save your preset then start again the next day or two after youve had some time to live with it and pick things out you like and dislike.

7. Once you get to a decent level, its easy to develop mindsets and tweak within a narrow band. That will limit your progress.

Again, this will depend on your install. You can reach the maximum potential of your install after a while. If youre not making any more progress and arent satisfied with the sound then its time to look into moving the speakers around and getting some better pathlenghts going on.

arun1963

***Tube light response***

Thanks bro. Picking up on point #7, I wrote that cause I felt that I was kind of stuck in a rut. Nice sound but not really improving at the pace I wanted. Over the last week or so, I've gone and redone practically everything. However, I still landed up more or less where I had started from in terms of sound quality. I was also sure that I had not hit the limits of my placement or tuning skills. Something had to give.

So I went back to your 08 finals tuning sheet that you posted in one of my threads. I know, different setup, environment, placement etc etc. But there had to be something there and there was. I looked at the printout of your sheet with that of the equal loudness curves. I still had to account for the natural peaks in the car, but boy it feels like being catapulted into a different level. I need to go back and do the L/R again, for sharper imaging. But I think I'm just going to soak this in for a few days :cheesygrin::cool:.

pentoncm

Arun or Mac, my far tweeters are measuring about 2db-3db hotter in the 4-10kHz region. Do you normally get this in your car or in vehicles you have measured?

arun1963

It will depend on a lot of factors like where the tweets are mounted, the axis relative to your ears, how close they are to reflective surfaces like the windscreen, pillars, dash etc. If you have the tweets mounted lower, then they will have a lesser PLD difference between them and the far tweet which is more on axis will be hotter in this range. 10-12khz is typically the beaming range for most 1" tweets and for sure the more on axis tweet will be hotter here.

In my case since the tweets are on the dash the PLD between them is much higher. Hence the near tweet is much hotter in the 2-5khz range and the far tweet is hotter in the 10-12khz range. Go with what your ears tell you. Most spl meters aren't very accurate in the 5khz+ range. Play the tweets only and try to get the image centred where you want it. Be carefull with the 2-4khz range from the tweets as this can add smearing, kinda like a snowy / diffused effect to the sound.

pentoncm

Check out the Audison Facebook wall. Two new products including the Bit Play HD and Bit Tune.

I think the Bit Tune looks interesting as this is Audison's first autotuning product. It looks like something dealers/installers will buy, but thats just me speculating. The mic apparatus looks fancy and they are marketing it as being better with a response closer to human hearing. It looks like you will be able to select multiple target curves as opposed to imprint and others that just give you a flat response. Anyway it would be cool to run it and try a few different curves and compare with manual tuning. It just generates a setup file that you would input into the Bit processor. You would then be free to tweak as you wish.

Bit Play looks like a new type of media center deal that can interface with anything type of drive you want. This media center runs every type of file including FLAC and OGG. You could encode all of your cd's as FLAC and keep it all in your car.

arun1963

http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eqloud.html

These are the Fletcher Munson equal loudness curves. They represent the human ears sensitivity to frequencies across the ten octaves. The chart shows that the human ear is most sensitive to frequencies in the 2-4khz range and least sensitive to the lower frequencies. While the relative sensitivity will change with the decible volume you're listening at, the basic pattern remains the same.

Once you move beyond the 2-4khz range the ears sensitivity again starts to decrease. If this is an accurate representation of our hearing pattern, then it stands to reason that while eq, you would want the sub frequencies to be the loudest with a gradual roll off in intensity to about 200hz. You would want 400hz to about 1khz to be flatish but lower by about 2-3dbs from the 60-200 range.

Going further, 2-4khz would be the range that you cut the most and you would set this ~ 3-4db lower than the 500-1khz range. You would start raising the level again around 5khz - 10/12khz. Opening 10-12khz range would also give you the airy sound and shimmer on your highs. Beyond about 8-10khz there would be a natural roll of in the car and your hearing in anycase. Once you have dialed things in take a FR response playing all drivers, and you should end up with a curve similar to the FM curves.

Point to note : The above does not take into account the peaks and imbalance that you would have at different frequencies which you would need to correct independent of these graphs. But yes, these graphs are a good trendline. Attached below is Mac's tuning sheet from '08 Finals. It pretty much follows the same pattern. For his install in the Honda, if he did a FR response curve I'm willing to bet that the curve would be close to the FM curves. Ofcourse we can't copy his settings cause they are for a different vehicle, placement, equipment, xover points etc etc. But I think the trend stands out.

Thanks Bro, I don't know how many times I've gone back to that sheet and eveytime I've learned something new.

arun1963

I'm not good with the science side of sound. Most of the technical stuff around this hobby goes over my head. These charts are an exception. Or maybe I'm just looking at them differently now. For instance, they explain why you lose your lower end when you turn the volume down. The difference between the most and least sensitive frequencies rises as turn the volume down.

It also explains why your ears would be more sensitive to any discrepancy in the sound, in your sensitive zone. Any sharp peaks or dips, L/R imbalance, phase issues to an extent, reflections and comb filtering etc. As also why you wouldn't bother about the difference between 0.1 and 1% THD in your lower end. It also explains why home and car audio are so different. Cause none of this would matter in your typical 2ch set up with you in the sweet spot.

But with this hobby, it always comes down to doing it by ear. With shaping the curve, you're covering for the way you hear and the effect of your environment, but you're still going to dial in the tonality by ear. The curve is just getting you in the ballpark. Mac shared his sheet about three years ago and I first saw the FM charts about a year back. I guess that proves if you stick with the hobby the sound will get better. No matter how much you suck at it. :biggrin:

MacLeod

pentoncm wrote: »

Arun or Mac, my far tweeters are measuring about 2db-3db hotter in the 4-10kHz region. Do you normally get this in your car or in vehicles you have measured?

Yes because the far side tweeter is more on axis with your ears and the higher the frequencies go, the more directional they become and their volume increases the more on axis you are to them and likewise the volume will drop more the more off axis you are. So it is natural that most of the upper frequencies from the most in axis driver will be louder.

I'd almost forgot about that tuning sheet. Those things were very handy and a nice backup in case you accidentally hit the wrong button and lost all your settings the night before finals!

pentoncm

Mac, thanks for posting your tuning sheet. It was helpful to see how your L/R differed on your mids. My near side sounds just a tad weak on the midbass and I'm trying to find where the problem is. Before I had cut everything from 160 to 400Hz by about 4.5 to 5db. I have to find the right balance but it sounds better to me bringing up 160Hz and 250Hz up to the -3db,-3.5db area. I need to play around with 250, 315, and 400 more though.

I feel that I am making progress.

MacLeod

Got a couple questions about that Bit Ten.

Are you guys running optical outputs to it or thru RCA's?

If its RCA's, how it doing for noise? I know my Alpine H700 when getting the head unit's analog output has some decent hiss if you turn the volume up pretty high.

Im thinking about getting one of these things for my system but will be using an analog output and dont want to do it if Im going to be losing 1 point every time for hiss. MECA judges are turning into noise **** these days.

arun1963

I had mine wired thru line level to start with and the tweets would randomly go into hiss mode. Just like you mentioned. I'm now running it with RCA's and it's good so far. The bit10D which takes digitial in is supposedly clean on this front.

The bit10 though will not let you do a 3way. I think with the 10D you can technically run a three way, but two of the three drivers on one side would share an eq between them. It's perfect for a 2way plus sub though. You will love eq in 0.2-3db steps :biggrin:

pentoncm

I only hear hiss when there is hiss in the recording like many rock tracks at the end of the song. On better quality material it is dead quiet. The noise should be lower with a headunit that has a higher output voltage. My Kenwood sends out a 4V, so the gain on the Bit Ten input is really low, around the 1 marker out of 5 (not voltage scale, it relates to amount of gain).

If you have a way to send a digital signal to the Bit Ten D it would be even better. If you want to invest in the new Audison Voce amps then the Bit Ten D can output 8 channels digitally all the way to the amps.

The Bit Ten D comes with the DRC remote while the Bit Ten doesn't. It costs the same to get the Ten D as it does to get the Ten + DRC.

Does it make sense that the processor should be more quiet if you use the DRC? If you don't use the remote, then you turn the Bit Ten output all the way up and then use your HU volume as the main volume control. This works but if you don't turn the HU all the way up then the processor receives a lower input signal (instead of 4V you could be sending 1 or 2V easy). This could lead to more potential noise in the system during average listening. I have the DRC so my HU is always turned up to max so the Bit Ten is always getting the maximum signal which should reduce noise.

MacLeod

Hmmm. No 3 way huh? That sucks.

The new MECA CD is going to have a zero bit track on it so theyll play it (dead silence) and turn the volume up to something like 30/36 on my Alpine and if they hear hiss, thats -1 point. Ridiculous really but thems the rules.

I had a CD player (9861) that has an optical output but its crapping out on me. Wont auto feed the CD, takes like 30 seconds to read the CD once you get it in there and its making funny noises. The first Alpine head unit Ive had a problem with in 20 years of buying Alpine.

So I really dont want to have to spend $600+ on a CD player with an optical output and thats assuming they even still make one! I dont think Alpine does and Im not sure who does other than those big $1000 double DIN touch screen DVD players. If I could get a processor that would work with an analog output but not have that damn hiss, that would be cool. Its bad enough Id have to slap $800 on my credit card for a Bit Ten, $400 for a laptop (but my wife really wants one so that can be more justified) and then have to buy a new CD player on top of that when my Alpine 9855 is still working great and looks cool too.

pentoncm

$800 for Bit Ten? No way. Bit One is $1000 up to 24db/octa and has 8 channel output. Bit Ten $400, Bit Ten D $600. DRC is $200 if you want to add it to Bit Ten. So you want to set up a three way plus sub? I would just go with the Bit One, see if you could find it on sale or something. Bit Ten has slopesve. Bit One goes up to 48db/octave. The Bit processors are supposed to be the cleanest on the market.

MacLeod

Oh OK. The Bit One was the one I was thinking about. The Bit Ten might still be am option tho. I need to look into that. I've got time alingment and crossover on my 9855 so maybe I could use that for my midbass or something. $400 is a lot more reasonable to maybe I can figure something out.

pentoncm

Check this out http://www.mobileelectronics.com.au/article/news/ps8_processor_from_arc_audio/

Looks like Arc Audio is joining in the processor fight
31 band parametric, and what the heck is a Bessel Crossover? Also you can change the Q of the crossovers? Audison better watch out

arun1963

Looks like SQ is making a comeback. Four new processors out or on the way. Arc, Helix, H800, 360.3. Pio is launching the P-80 which is an upgraded version of the P-880/800. Lets you go 3way+sub with improved interface ability. Alpine though seems to be going the other way.