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Discussion Starter · #1 ·
I thought it would be a good idea to collect all the tips people have in one thread. There is a lot of information on DIYMA, but it is getting kind of buried, and people may not have seen it.

This thread is for hints and tips, not for Alpine/Imprint haters - start another thread for that if you must.

Essential Reading

Important Tutorial Post from an Alpine Trainer

Source thread for the above with more info

Tips from someone at Audessy at the bottom of the post

Dang's review of the H650 and Imprint, his comments are important, coming from a good tuner

9887 Imprint review thread, very long, much nonsense, but important information is imbedded in it
 

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Discussion Starter · #2 ·
Imprint pre-run checklist for 9887

This is the list of actions that I perform before each Impint run. It is long because I have actually missed about 1/3 of them in the past, usually because I was in a rush.
  1. Mark ear positions on windows with masking tape
  2. Remove headrests, lay them on backseat
  3. Turn key to "Accessory" position, not the one just before "Accessory"
  4. Turn on head unit
  5. Check that balance is centred
  6. Check that Bass and Treble are zero'd
  7. Set Sub level the way you want it*
  8. Set amp gains appropriately **
  9. Set subwoofer gains down by 6-12 dB
  10. If running active, set the crossovers in the head unit to the values required (only necessary if changing them from the last run)
  11. Turn off HU and remove faceplate
  12. Connect mic to control box
  13. Connect contol box to HU. Make sure the green LED comes on.
  14. Connect control box to laptop. Listen for "USB connected" beep.
  15. Setup mic in the first position
  16. Start Imprint and select left front seat

* Some say to zero it, some say to use a number in the middle of the range, the smartest answer is probably 15 since that is actually full output on Alpines. I will use 15 on my next run.

** 1/2 or just under on my SS Ref500SX seems good for the midrange. 1/3 or a little higher on my PPI4240 for the tweeters
 

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Discussion Starter · #3 ·
Imprint tuning hints

  1. Mark ear positions on front and rear windows. Sight across the car to line up the mic fore and aft and up and down for each measurement position. This is super important.
  2. Tune for the drivers seat, nobody else in the car gives a ****.
  3. Follow Scott's recommendations for mic positions (all at head position fore and aft), taking measurements forward on the seat (as directed by the software) seems to rob you of bass. I may try Chris from Audessy's recommendations one day when I'm bored.
  4. Set sub gain down before running, back up again afterward. Don't get carried away though. If you set the gain too low, the sub will not be detected and will not be EQed or T/Aed.
  5. It may be necessary to set the gains on the tweeter amp down a tad after running Imprint.
  6. You can vary the tilt of the curve applied by manipulating the gain of the tweeter amp. I am still figuring out how to do this consistently. If the gain of the tweet amp is relatively high, the post Imprint result will look very flat in the graph, but sound very bright. If it is juuust right, there will be a general sloping down that sounds quite good. If the tweet gain is too low (even if it sounds OK), Imprint may not detect the tweets, and no joy results.
  7. If running active, Imprint has no idea what kind of drivers you are using so set the crossovers yourself in the 9887 before running Imprint - it will respect the crossovers. In fact, the only crossover Imprint will set in an active setup is between the sub and the mid, and it will usually be wrong. I think, however, it might do a better job if you are running a conventional setup with two pairs of passives. It would set an appropriate crossover that makes the front and rear both blend the best with the sub.
  8. If running active, protect the tweeter from the mls chirp, it is full range. Use a cap or set a HP on the tweet amp.
 

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Discussion Starter · #10 ·
Personally, I have not seen anything to prove it even exists.
 

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Discussion Starter · #21 · (Edited)
This post compares RTA results to the Imprint result screen from my latest Imprint run.

This Imprint run is the first since I installed my PA BB175.4 amp to run my mids. Initially, I just plugged the PA in place of my SS Ref500sx, and set it's gains to sound good in the previous Imprint setup. The first RTA trace is that setup, but with Imprint turned off.



The second trace shows the levels set prior to the new Imprint run. I just try to get the tweeter level set to look similar to the top octave of the mids, or a little lower. The tweeter highpass is 2.5Khz/12dB.

Before running Imprint, I also turned the sub gain down 12dB, and applied an 8dB narrow notch @ 40Hz to try to knock down the 45 Hz resonant peak. Those changes are shown in this trace.



The following two shots are the Imprint filter result predictions. I always load the "Reference" and "with Midrange Comp" curves, but generally try to use the "reference" curve.




This RTA trace is of the results when the "reference" curve is used.



The red trace is with the sub gains still turned down, the blue trace shows the result of turning the gain up to maximum on the sub amp, and another 2 dB cut to the 45 hz peak.

These results sounded good in the Bass and lower MR, but were really too bright. I have been driving around with this setup for a couple of days and have been progressivly turning down the tweeter level. I have a result now that sounds awesome at medium to highish levels. I think I have likely turned the tweeters down by about 6dB. I will try to setup the RTA to take an after measurement.
 

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Discussion Starter · #23 ·
Crossing the mids and tweets closer together makes no difference to the dip at all. The low crossover on the mid is my latest effort to take some of the energy out of the audible 1.8kHz resonant peak. I have tried symmetric and asymmetric crossovers from 1.6Khz to 3.2Khz, and all tend to be harsher and brighter sounding.

I tried flipping phase a few months ago and was not happy with the results. I am going to try it again though.

At this point, my car is absolutely the best I have ever heard. That is not saying lots, since I do not go to competitions. The few show/demo cars I have heard have driven me away through a combination of hip-hip and obnoxious loudness. I have ridden in a few cars with premium OEM systems, and this one beats the ones I have heard for detail and natural, up-front bass.

This setup is the smoothest and appropriately bassy enough for the highway. My system has to support 5 and 8 hour highway trips without being fatiguing. The increase in power to the mids has made an enormous difference.

There is more work to do, but the results to this point are certainly useable enough.
 

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Discussion Starter · #25 ·
I just set up for one seat. The only time it matters is on long trips when I take a break in the passenger seat. The rest of the time, my wife really doesn't care or notice. I think I only ever set it up for "all" once, and was not that crazy about it.
 

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Discussion Starter · #27 · (Edited)
Normally, I set the sub/mid crossover before running Imprint. In the past, the few times I let Imprint set the crossover itself I was not satisfied. I experimented with 63, 80, 100, and 125.

Since I had more power available for the mids I decided to try something different.
This time, I actually set the sub/mid crossover flat and let Imprint set the crossover itself. I have to be honest, this has provided the most consistently up front bass I have ever had.

It looks like there is a hole centered around 100Hz, which does make me wonder if there is a phase issue, assuming Imprint set the crossover at 100. I will try reversing phase on the sub and see what happens. Probably screw something else up.
 

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Discussion Starter · #51 ·
Imprint defeats all settings on the headunit...if it didnt, everyone could get 3way active to work.
This is incorrect for the 9887. Imprint respects the crossover settings in the headunit. This can be confirmed by using an RTA after tuning.

The last few times I ran Imprint I even let it set the sub crossover. I am not a bass head and prefer higher sub crossovers for better integration anyway. I get very consistent up-front bass.
 
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