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Discussion Starter #181
As a side note my wife was in the car a couple times this weekend and complained up and down how there is not "low sound" up front as if a car behind me was playing the bass notes, not my car. You need to put the speaker up front to here it, LOL. Shes critical and has a good ear. Also complained that the sound doesn't surround or envelope you, as I really dont have rear speakers running (off deck power only) shes right. So this morning I put in my time delays using measurements (inches converted to ms) and she listened to it again "ok that better, not great, but better". Incredible how timing can make you think a speaker is somewhere else. HA!!
 

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Yes exactly. And if you click all SPL on the top, you should be able to see all the lines on the same plot, to see your system overall.
 

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Ok, so its looks pretty good for the most part.
There were a few sets of measurements there, I chose the one that seemed to be furthest above noise floor. This one the sub measurement didn't seem right, so I didn't include it in the graph. I merged everything together to get a nice picture of the whole system, left and right.


As you can see, they kinda merge together at the lower frequencies.
Was the engine running when you took the measurement? This could be engine noise, with measurement level not being high enough. Or, it could be an accurate measurement, with the similarities between left and right down low just coming to due the acoustics of the car. Also, the tweeters seem to roll of after about 12khz, which seems a bit odd. Not sure why they would do that.

Just to be sure, I would take measurements again at a higher level.
Below is a measurement of my system from a bit ago before I upgraded my speakers, but as you can see from the scale on the left, the overall level is higher, just to make sure no background noise gets in there. Also I took measurements with the engine off. (the two lines are from two different bass knob positions)
 

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Yeah I always take measurements with the engine off. Of course, this time of year, I have lost about 10lb of sweat out in the car with no A/C. I will usually run the A/C full blast for a while with the car in the shade and then turn it off to take measurements (real fast). THX, you are in S. Florida so that must be tough. Got a garage?
 

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Discussion Starter #195
Nope, garage converted into a guest room before i moved to this house. But year is been hot AF down here and the humidity is killer. Under working circumstances as a tech i love the heat and everything including the buckets o sweat it brings, but at night trying to tune the car, not fun.

To be honest I'm not sure if or which of those measurements were taken with the car running or not. I know i had it on for a couple at least (2 sets one using the measurement button the other using the rta button). I was in the back seat to not block the sound going to the microphone. Maybe it would have been smarter to put the laptop on the roof and let the little bit of breeze keep me from melting!

I will start over again tomorrow, making double sure the settings are correct and the engine isn't running. Wouldn't it be smarter to have the engine running as a true example of how we would be listening to the system? I'm probably wrong but i always wondered that. Below is they picture of the microphone placement from earlier today as i was planning things out. I used the 90⁰ calibration file which i hope it's correct.

Spwath, do you mean to say that the engine running causes that merging of the lines down low? I guess that could be possible as the car does have a decent low rumble. As for the recording volume I had it at 21 of 38. I usually max out as far as turning it up at 25-26. Anything higher than that has no appreciable increase in sound, as if the head unit stops at that point.

Should i go to that point or maybe turn up the gains more? To tell the truth i don't know if the gains are setup correctly, I have them on the LC6-1200 at the mid point for the midrange and mid bass, and the tweeter just a hair short of mid point as i think they're too bright in the middle position. As for the levels on the DSP i even have the tweeters down about 5db for the same reason. I don't have an O-scope to setup to clipping etc, maybe with a DVOM?

Not sure why the tweeters would be rolling off at 12k I don't have a filter or anything on them, right now head unit and DSP are both flat. I really don't feel much out of the midbass based solely on the pink noise measurements and my ear. By the way just to be clear the recording files i sent were sweeps from REW, not pink noise. Is that correct?

Sorry for the long post guys lots of info to get in. Thank you!

Sent from my HD1905 using Tapatalk
 

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Actually I wouldn't worry about that rolling of up top. These "cheap" mics are not that accurate in the extremes of the audible spectrum.

Yes, I was saying it could possibly just be getting the engine noise down low. You are right, it might make a difference to have engine running with high voltage, but I wouldn't think it would be too different.
And you can have engine running, just have to make sure that the measurement level is enough above the engine noise level.

I personally just set my gains with a multimeter, worked fine. I do have an o scope, but need to get a 10x probe to set amp gain. Used it to check if head unit was clipping though.
 

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Discussion Starter #197
If i have the engine running and I'm using the sweep from the laptop to the aux input (1/8" jack) i get alternator whine, i remember now i did those with engine off but i will try measure tomorrow to make 100% sure.

I meant about taking into consideration the engine running as part of the tune to approximate how I'd normally listen to the car, rarely if ever do i listen to the system with the engine off. But let's not reinvent the wheel. I'll be sure everything i do is with the engine off.

How did you set the gains using a dvom? I'd love to be able to do that!

Sent from my HD1905 using Tapatalk
 

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I've got the Helix, so obviously my "procedure" is different, but basically I will mute all but the driver I am going to measure, run my uncorrelated pink noise and press record. I record until about 100 averages, stop and save. Then I'll move to the next driver. My pink noise is 4-5 minutes long and I just run it on the loop so I usually just keep it playing. I usually put ear plugs in because I will play it up around 90-95 db (you can see this level in the RTA screen). It's not too loud, but after listening to that crap for a long period of time, my ears start to ring. I'll go through each driver and then go back and name/save them in the main screen (L Tweeter, R Tweeter, etc.).

For setting gains with a voltmeter, start watching around 3:30:

 

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Discussion Starter #199
It's funny (not) I've seen that video a few times and never caught on to the fact of setting gains using the DVOM. Marc's videos are always very informative, good watching. So I went square one and set about to set gains as instructed. I followed the video about and a write up over at Sonic Electronix. In the instructions from Sonic it mentions disconnecting the positive wire from the speaker output (I assume so as speakers aren't actually powered) and I did so. However to my dismay and bewilderment I found a couple issues I didn't know I even had!! First one of my tweeters was hooked up in reverse polarity (no clue how I missed that one) feeling stupid right now,ugh. Second as you might have seen in my latest pics of the trunk/amp board layout, i am using terminal strips to connect the speakers/amp.Well guess what I didn't fully crimp 8 of them!! Soon as i tugged on them lightly to disconnect them I noticed the wire moving freely inside the crimp terminal and if i pulled straight out they came out without even damaging the copper! Needless to say I re-checked all of them to ensure a tight connection. replaced the loose ones and the others were secure.

On to the gain setting, I downloaded from the JL Audio website a set of 50,200,1000 and 8000 sine wave (3 min long) files along the stereo and mono pink noise (15 min those last 2)files to use. Setup my DVOM (glad I didn't sell it when i stopped turning wrenched for a living) for AC voltage and made sure the loose speaker connectors did not touch anything. I fired up the files using the 200 for the mid-bass channels, 1000 for the mid-range and 8000 for the my tweeters.Using the math provided,square root of 125x4 for my particular amp, the voltage should be 22.36 volts. I was able set set it to 22.3 with a bit of patience as the gain pots are touchy things, endless procession of back and forth before getting hat i needed. Interesting side note this was the first time I'd ever seen the "maximized" led light up on my Audio Control amp. They came on just a touch past the 22.3 volts for the tweet and mid-range. The mid-bass channels never lit up even when fully cranked. I set that one back the indicated 22.3 volts and left it there. I honestly didn't set up the Sub gain as I can easily over power the speaker with the Pioneer amp and feel I have a decent amount (lets see what measurements say later).
 

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Discussion Starter #200
Neglected to mention above that I also changed my volume position for testing (25) and also used 28 as my gain set point as it is .75 of the full volume (38).I then began prepping to make a fresh set of REW measurements. Made sure everything as far as EQ etc are all flat, brought back up the tweeter levels in the dsp from -5 to 0. Placed my microphone in the same position (best i could tell) and used the mono pink noise for the individual speaker channels and the stereo pink noise for the "all" speaker recording. Recorded each speaker in succession with 30 averages each (used less the first time). I will include the pictures below. I placed the laptop on the roof of the car with the wires for the dsp and mic coming though the door, to make the measurements.

Also got in the mail today the Bluetooth dongle for the Dayton DSP, this should allow adjustments etc to be made a bit easier on the fly and also stream music using the APTX capability. Tiny little thing, I'll mess with it tomorrow.
 

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