Final DQX test Results
03-19-2004, 09:20 AM
#6
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
Mark, I've got a funny story for you.
Yesterday I got my Dad's Lab grade RTA going. I was doing graphing up the ying yang....stuff that would make most SQ guys drool.(I was)
I set up the RTA to do a 500 (five hundred...not it's not a typo) point sweep from 20hz up to 5Khz. Let's just say I had tons of resolution. I repeated the test with the microphone in 3 positions, passenger's side, middle of the car, and driver's side. The results were pretty uniform with one exception in the midbass area around 200hz. (but I already knew about that from listening) I lowered my bandwidth from 20hz to 400hz and set my sampling at 200points. This yeilded pretty smooth graphing with lots of detail. Once again, I repeated the sweep from 3 positions to confirm uniformity.
Then I started using the DQX. First I played with X.O. points, then time alignment between the subs and midbass, and mibbass and midrange. Then I started to EQ. I spend several hours working on averaging the peaks and valleys to +/-3db at 105db. At the end of it, I have a really flat graph that averaged pretty well the same from all 3 mic possitions.
Then I got in the car and listened to my work. It sounded dead and unmusical. In short it sounded like crap.
This is not the first time I've had this experience. I once inserted an EQ into a $50,000 2 channel home system and had the same result.
The sound I got from EQing the car flat could have been done using any EQ, the result is not due to Audio Control making a bad EQ. Any EQ can make a system sound bad.
My point is that once again, having great equipment to work with doesn't mean you'll get great results. I'm sure most of you would kill to have access to a good RTA, and a good EQ in your system. My experience says that it doesn't always sound good having flat frequency response.
The signal does get degraded by putting the DQX in the signal path as Fuel37 has heard. I have made this statement before. But as Mark points out, it is possible to have an EQ do more good than bad in a system. I admit that the possibility is there, but you have to work pretty hard to find it.
An RTA is a pretty good tool to tell you what is going on in a car, but it's you're ears that are always the final judge.
DXE?
Adam
Yesterday I got my Dad's Lab grade RTA going. I was doing graphing up the ying yang....stuff that would make most SQ guys drool.(I was)
I set up the RTA to do a 500 (five hundred...not it's not a typo) point sweep from 20hz up to 5Khz. Let's just say I had tons of resolution. I repeated the test with the microphone in 3 positions, passenger's side, middle of the car, and driver's side. The results were pretty uniform with one exception in the midbass area around 200hz. (but I already knew about that from listening) I lowered my bandwidth from 20hz to 400hz and set my sampling at 200points. This yeilded pretty smooth graphing with lots of detail. Once again, I repeated the sweep from 3 positions to confirm uniformity.
Then I started using the DQX. First I played with X.O. points, then time alignment between the subs and midbass, and mibbass and midrange. Then I started to EQ. I spend several hours working on averaging the peaks and valleys to +/-3db at 105db. At the end of it, I have a really flat graph that averaged pretty well the same from all 3 mic possitions.
Then I got in the car and listened to my work. It sounded dead and unmusical. In short it sounded like crap.
This is not the first time I've had this experience. I once inserted an EQ into a $50,000 2 channel home system and had the same result.
The sound I got from EQing the car flat could have been done using any EQ, the result is not due to Audio Control making a bad EQ. Any EQ can make a system sound bad.
My point is that once again, having great equipment to work with doesn't mean you'll get great results. I'm sure most of you would kill to have access to a good RTA, and a good EQ in your system. My experience says that it doesn't always sound good having flat frequency response.
The signal does get degraded by putting the DQX in the signal path as Fuel37 has heard. I have made this statement before. But as Mark points out, it is possible to have an EQ do more good than bad in a system. I admit that the possibility is there, but you have to work pretty hard to find it.
An RTA is a pretty good tool to tell you what is going on in a car, but it's you're ears that are always the final judge.
DXE?
Adam
03-19-2004, 02:49 PM
#9
Guest
Posts: n/a
whoa whoa whoa...
"...At the end of it, I have a really flat graph that averaged pretty well the same from all 3 mic possitions..."
FLAT? flat like as in the line was flat with no pitch to it at all? um, yeah I would think that would sound like total **** actually
flat sounds bad. I shoot for 'smooth' with gain in the bottom two octaves. [img]graemlins/thumb.gif[/img]
"...At the end of it, I have a really flat graph that averaged pretty well the same from all 3 mic possitions..."
FLAT? flat like as in the line was flat with no pitch to it at all? um, yeah I would think that would sound like total **** actually
flat sounds bad. I shoot for 'smooth' with gain in the bottom two octaves. [img]graemlins/thumb.gif[/img]
03-19-2004, 04:12 PM
#10
1000 Watt CAFz'r
Join Date: Oct 2003
Posts: 1,783
I'll email you a screenshot Dukk. PM me your email address if you want.
and yes it was not ruler flat, I had lots of dips and peaks, but nothing over 3 db.
I also agree with you about the bottom 2 octaves, I like to feel that energy.
Adam
and yes it was not ruler flat, I had lots of dips and peaks, but nothing over 3 db.
I also agree with you about the bottom 2 octaves, I like to feel that energy.
Adam
