Alpine CDA-9887 + KTX100-EQ: Notes
I’m making these notes in the hopes that they will help others who tune their Imprint-based systems using the Alpine KTX100-EQ. I am using it with the CDA-9887 head unit, and I’m increasingly glad that I purchased instead of renting because it’s hard to get right.
In general, the system does exactly what it says, it results in a pleasingly flat system with all speakers time-aligned, and the image up on the dashboard. I really like the way it sounds, and it’s amazing. However, I do have complaints, which I am going to detail here:
Set everything to flat before you start!
So… if you set the parametric/graphic EQ, or the delay compensation, or the enhancement, it will interact with the Imprint settings. You really want the enhancer turned off! Why doesn’t it say this in the manual somewhere?
Did you do funky stuff with speaker phase?
If you’ve done anything funny with phase, undo it now! I had swapped the phase on my front tweeters intentionally, and forgot about it. (Well, it sounded better that way.) If you’ve done this or any other tricks (switch the phase of the right side door speaker, etc), undo it now. The Imprint software assumes all of your speakers are in phase, and does not compensate for this!
My system sounded *really weird* because the front and rear tweeters were perfectly equalized and delay-compensated, only to cancel out at the driver location because of the phase. Don’t do this!
Your non-imprint settings interact With Imprint
If you change your EQ settings after storing an Imprint preset, it will mess it up. Same goes for the Timing. In general, if you use Imprint, you can’t touch the manual settings. Why doesn’t it say this in the manual?
The Pros remove The Headrests
That’s right. Professionals remove the headrests before starting.
Don’t use 3-way crossover mode!
My system is pretty normal: there are full-range speakers in the doors and on the rear deck, and a sealed sub in the trunk that runs off of the right channel only. The rear deck speakers are 6x9s, so I would really prefer to feature the Quart separates in the front doors, which I found I could accomplish by switching the 9887 to 3-way mode and rolling off the treble for the rear deck. There’s a switch on the bottom of the 9887, that lets you select either four-speakers-plus-sub mode, or 3-way mode.
So, why am I telling you all this? Because if your speaker is in 3-way mode, the Imprint software will think you only have two speakers, it will totally make something up, and then it will let you upload it to the head unit. And it will sound.. pretty good. And then, if you’re me, you’ll drive around for a few weeks wondering if this was really worth the extra money.
So, if you’re going to use Imprint, don’t do this–I reprogrammed mine to four-speakers mode and Imprint sounds amazing.
Did it detect all your speakers?
Here’s another hint. After taking measurement 1, look to make sure there is a circle next to each speaker in your car. If not, this means Imprint did not detect that speaker. (I accidentally pulled the wires out of my sub at one point, and did an entire measurement before I noticed it wasn’t working.)
Why did it erase slot 2?
When I uploaded a preset to imprint slot 1, the one in slot 2 disappeared. Is this right?
I have a Tripod for the Mic — Now What?
The manual suggests getting a tripod. This is good advice–I tried just using old cardboard boxes and it’s almost impossible to put that mic where you want it. So, I’ve been using a Targus 42″ travel tripod, and it’s ideal for this–I just shove the legs to any length I need–it’s not the highest quality tripod I’ve ever seen, but because it’s a travel tripod the legs can be folded very small, which is nice.
But some things are not clear. For example: when you are supposed to take a measurement at the headrest position (as indicated by the mic icon over the headrest), should the mic be where the head goes, or where the headrest is? Also, my headrests are up high to prevent whiplash–should the mic go in front of the headrest, or should the headrest be removed?
I think this is important, because when I rest my head back on the headrest, the stereo image moves from the dash and seems to be coming from the passenger seat–I must be doing something wrong–it’s setting up the delay times perfectly for a head slightly in *front* of where my actual head sits. :)
Just a little more information? Please?
If the program had a status window that printed out simple log messages as it worked, I would feel much more confident that it was working right. For example, it’s clear that the software is making decisions like this:
Testing right front speaker.
Found right front speaker.
Calculating gain and delay time.
Testing right rear speaker.
No right rear speaker found.
I know it’s generally useless information, but when you’re standing there for 15 minutes watching your car go “blip blip blip”, you’ll actually read it.
A Little More Control. Just A Little.
Other things I wish I could adjust.
- I wish I could put just a little less power into the rear speakers, and equalize for that.
- I wish I could raise the high-pass frequency on the front door speakers–they distort too soon from bass.
- I wish I could superimpose my own EQ preference
Heard of Linux?
The control software is .NET, so it should be trivially easy to run it under Linux using mono. However, they have linked to microsoft DLLs, so this does not work.
I normally wouldn’t care, but my laptop runs Linux. I’m getting tired of carrying the water-cooled game computer up to the garage.
A one-day rental is too short.
After spending all Sunday measuring my car, I only have one of the two presets saved, and that one doesn’t sound right if I put my head on the headrest. You probably won’t get it right on the first try.
Done whining for now
Anyway, that’s my notes. Enjoy.
Updated: spring of ’09 — speaker phase information.
