Poor SQ

Ishouldbeworkin

I got my Alpine HU and my pxah701 processor and the fiber optic installed, and threw a little more stuff in to dampen road noise while I was at it... then on the way back from my home town in a dark area in the middle of nowhere..hit a truck tire.. wrecked the front bumper of my g35 doing like $2500 in damage and couldn't see my car for 2 weeks or play with any of my new gear.

But, I am back now and time to start tuning all over again...

While I was working on everything, I redid the ground mounts under the rear seats...scraped the paint really well and added some washers to keep the wire loops in good and tight. So far, it's starting better than last install. No engine noise ...

I have not really tuned anything yet, but I will begin tomorrow. So far I have noticed that the bass started out really really loud and boomy... I had to turn the gain on my PA 1200.1 all the way down and set my sub on my sound processor to -12 and cross it at 40Hz with a 30 db slope just so i could stand to listen to it little.

I also had to increase the gain on my PA 500.4 to about half way, but still hear no appreciable noise with the fiber-optic in play. At the current settings, I can turn the HU up to 35( max ) and still be listening at a comfortable level. This will change, I am sure as i get in and begin to take measurements and make adjustments.

It does seem a bit strange to go from worse to better gear and go from good to bad sound. I guess it shows how much tuning before really did help. Will drive out to the park tomorrow for some place with no background noise to do my measurements.

Thought I might post some pics of the install etc. also while I am at it. Note, I had already started disassembling on the "before" pic, lol.

arun1963

believe it or not, I was all set to bump my post count by wondering where the hell you went Haven't read your post yet. Just read the title and posted this. Pics mean you've been a busy boy.

arun1963

Random post on tuning......

One of the great things about tuning, is that if you stick with it, it teaches you to listen and hear the difference. So if you cloud'nt measure a range accurately, you'd have to go with your ears. I don't think we know enough about sound and how we hear, to put everything down into pat formulae. Measurements at best are starting points.

So while your PLD may measure 17", you may find that it sounds best at 10". But if you manage reflections you could set it closer to 17 and have a wider stage. While you can use the spl meter and test tones for the 20-500hz range and get very accurate results, reflections muddy the readings beyond 800hz. The meter gets a bit more accurate after 5-6khz. So 800hz to 5khz has to be set by ear. That is why this range is the toughest to balance for L/R and then level match.

When you get this range right not only will you have good tonality, but you will be able to open up the highs and locate the vocalists mouth on your image. Of course all the other things have to be in place as well. If this range isn't set properly and everything else is, it just won't sound right.

Having a processor in your sound chain is highly beneficial in this range. What the mids are doing at 3khz are not what the tweets are doing. So having one adjustment for both will work better for one set of drivers and maybe poorly for the other.

When tuning the 800 - 5khz you're thinking and tuning across four different ranges. Your mid bass, midrange, upper mids and into your tweets. If you boost something here you may have to fill in a bit from either the mid bass or from your top end or both, depending on what your boosting.

A bit extra at 200 and 315hz gives you the initial feeling that your mid bass has greater punch. What it also does, is to muddy your mid bass and mid range. Both frequencies are about the max that you can run them at and then not going further. If you still feel you have to, something else is wrong some where. There's also a major L/R imbalance happening at 315hz.

500hz is part of the frequency chain that anchors your image. 50-60hz at the bottom, 500hz and 1.2khz in the middle and 6-8khz at the top. Balance here helps in anchoring the image. Boosting a bit across this chain, brings the sound alive after you have got everything well balanced but a bit dull.

It bears mentioning that 1=1.25khz is where your sibilance issues are starting the pronounced and stretched 's' sound. If your L/R balance is out over the 1.25-3.5khz range, you may also face the issue of the 'aahh' sound. 1.25khz-2khz is also where your brain starts to process height cues. Frequencies that are much louder on one side, will generally shape up louder than those around them even when corrected for l/r. Once balanced they generally need to be pinched down on a bit. 160hz, 315hz, 3.5khz are some.

800hz and 8khz are the two ends you look at while opening the vocals. Vocals go lower, but thats only for finishing touches. These two frequencies are linked and once balanced, you boost or attenuate them together. This is the also the range that has the max information on most music.

800-5khz is also the range used to open up the vocals. It does not mean adding 'air' to the sound. Air, is at 12.5khz and what you add at the end. If you open 800 and 8khz a bit, you will have to fill in the extra space available by boosting everything in between and vice versa. Of course while maintaining l/r balance for all frequencies. With the sr's there is a distinct peak at 800hz so this is also something you have to account for. Boosting too far at 800 hz dulls the snap in your mid bass. 3-3.5 is beaming, your far mid is much stronger than your near mid.

The op posted this graph after his initial tuning sessions. Whatever the settings that yeilded this graph and assuming L/R balance, here's what I would do. I'm going purely on how loud the test tiones sound when I have things set somewhat to my satisfaction.

I'd boost a bit at 125 about in line with 100, maybe pinch down a bit at 80hz. I'd have to hear it to know for sure. Pinch down a bit at 160 and more at 250-315. I bring down the 1-1.6khz range a bit, around 75db. Even when set well you may find these a bit brighter than those around it. I may look at boosting 3.15khz in relation to the 1-2khz range. Try it both ways see what sounds better. Bring 5khz & 6.3khz down and open up 12.khz a bit. I was'nt really going to add this last para since its not right to post it without hearing it to know for sure. I just have a strong hunch that it would shape up better this way.

Last bit, if you're measuring for L/R for 1khz+ with the test tones, try doing it in a quiet surrounding with your windows rolled down or by covering your dash with a big beach towel. A thick pile helps.

arun1963

hey, ISBW how goes the tuning? No news.......:)

arun1963

Welcome to the wonderful world of temp mount . Play with angles on both axis. Don't be in a rush to do the permanent mount.

Both you and TTT are facing the same issue. 1-4khz is much louder from the far side and this is an important range for vocals and the harmonics of most instruments. Beaming causes this range to swamp the image way to the left. The left and centre stage are squished together in front of you and to your left and you dont have much of presence to the right.

The more the difference between on axis / off axis, the bigger the issue of beaming. Hence doors are the worst place to mount your speakers, if you don't have L/R eq to tame the beaming. TA may help slightly but it's not a cure, for sure.

Which is why kicks were the rage with sq competitors in the late 80's to early 90's. It reduced the on axis off axis issue and reduced the PLD as well. DSP ofcourse hadn't been invented back then.

In your situation (assuming you have your mids in the door), I'd try the following to see if it worked. Bring your tweets on axis, thats the way the sound the best. Cut the mid at around 2khz on the steepest slope. Run the tweet down to like 3.15khz again on like an 18db slope. By staggering the mids and tweets you're creating a bit of a hole at the problem frequencies, so the impact of beaming may be reduced. Play with the slopes a bit. You may need to boost a bit at 2-3khz to maintain tonality.

I know crossing at 4-5khz gives great height and better definition, but all that is kinda wasted if your stage doesn't have the width and presence. You may still have have a slightly blurry image (instruments, vocals moving around your stage as they go through different frequencies) but your stage would be wider and more balanced.

The vocalist is recorded centre stage 99% of the time and its important to place this at least around the centre of your windscreen. This way left and right stage have equal space to develop and you would get good width.

Kicks may work really well for you. Hope this helps.

TakeTheTime

Yeah I can see that, Arun. For me the issues on the far side is reduced more when I cross lower...

arun1963

Hows the tuning going on the prs?