GAIN OVERLAP EXPERIMENT for SQ

[Serhal702]

First of all my system is an active setup:

Pioneer DEH-80PRS

1 Arc Xdiv2 1100.1 running @3ohms (with bass knob)

1 Arc Xdiv2 600.4 4x150wrms

Morel Virtus 602 component set w/ sealed and deadened doors bandpassed 80-2500hz

JBL w12gti mkii sealed @ 1.0ct^3 lowpassed @ 80hz 

24db slopes all around, and eq only has cuts no boosts. 

I set gains with a DD-1 at -5db for mids, and -10db for the sub. The gains on the amp for the tweeters are all the way down, somewhere between -0db and -5db to be safe. I also try to download 95% of my music as FLAC and play it through USB connection through the headunit.

I listen to all kinds of music, but usually stay away from modern rap with huge sine wave bass lines. I try to stay in the clean limit for how loud I can go for a specific album of music, but I really wanted to know the numbers of how high i could really turn it up with no extra distortion from clipping etc.

I tried to tackle this issue by uploading a track into audacity for analysis. I started with Canada by Devin Townsend. I pick a louder selection from this piece and analyzed the plot spectrum. I chose 16834 for size and log for axis. It showed that the highest peak was at 77hz @ -13.7db. If I just look at the entire piece of music there are peaks at -.4db. Does anyone know how these are different or correlated? Does this mean I can play this song at full blast without any clipping? And how should one adjust gain overlap accordingly? 

My music sounds good and gets loud and I usually have a good ear for distortion, but I also want to be sure I am not going severely clipping on more modern music with synthetic bass and whatnot especially when I give a demo.

 

 

 

 

 

 

[ShadeTreeMechanic]

The DD1 is a useful tool for setting gain levels because it is helpful to have a reference if you want to play at full output. But that's all it is, just a reference. Some transient peaks can be played just fine without clipping, and others cannot. It all depends on the equipment, the crossover frequencies, impedance rise etc. every system is different in this regard. Too many variables to say that any song won't clip at full output unless the gains are set conservatively. Usually amplifiers will be over sized to provide tons of head room to prevent clipping while never playing them near max output. A 100w amp at half power will generally sound better than a 50w amplifier at full output. So at the end of the day it is up to the operator of the system to know to turn it down a little when the system complains.

[White Lightning]

Why do you have everything set at such a steep slope  ??? On A lot of heavy slope setups, you can normally tell where the drivers are located in the system. This is one thing you do not want in a Sound Quality stage and image application.

My Sound Quality setups usually love the 12 DB slope blend. More of a natural sound ... Heck, even on the way lower end of the spectrum, my may have been set to low as 6 DB. Can't remember, need to check my paperwork. 

ALOT to testing and tuning can be done here ... Just saying

Hope I didn't get too far off topic ???

[Serhal702]

@White Lightning It sounds good to me. Others have heard it as well. I went to a tuning seminar for Arc Audio taught by Fred Lynch, and he uses them if I remember correctly. Also I have a year (only) of experience working with Jon Webb as his apprentice in Las Vegas who uses 24db as a starting point to tune active vehicles. Either way, every car is different and sounds different; but in my car, there is a high stable center image maybe 4-6 inches above the dash. All midbass frequencies are above the dash, including most sub bass. Any lower frequency maybe under 35 is all around you, etc. If you sat in my vehicle eyes closed I think it would be difficult to pinpoint anything besides the tweeters since they are on sail panels and the image rainbows a little bit. The 6" speakers in the doors are transparent. Moreover, I have heard more than one vehicle that have 24 db slopes that sounds phenomenal, including Bob Morrow's Honda truck with Audiofrog components (trying not to name drop but thats what Ive heard). I have also heard vehicles that sound good with more shallow slopes.

I have to add that my car isn't perfect it definitely needs more time on the RTA, but after just a little time flattening the frequency response the imaging became much better. Most of my time tuning has been playing with levels, phase, and signal delay, but I postponed it until I can get a couple hours in on an RTA. You did go off topic, BUT i dont mind brother, knowledge is power!

 

[Serhal702]

4 hours ago, ShadeTreeMechanic said:

The DD1 is a useful tool for setting gain levels because it is helpful to have a reference if you want to play at full output. But that's all it is, just a reference. Some transient peaks can be played just fine without clipping, and others cannot. It all depends on the equipment, the crossover frequencies, impedance rise etc. every system is different in this regard. Too many variables to say that any song won't clip at full output unless the gains are set conservatively. Usually amplifiers will be over sized to provide tons of head room to prevent clipping while never playing them near max output. A 100w amp at half power will generally sound better than a 50w amplifier at full output. So at the end of the day it is up to the operator of the system to know to turn it down a little when the system complains.

I think there must be a more technical answer to resolve this. For example, If I set my gains at -0db overlap with an o-scope or DD-1 it would be without any crossover slopes, eq, or signal processing of any kind etc. Then I know that any song that is not already clipped in nature will not clip as long as I dont boost eq, add bass boost on the amp, or use loudness, etc. But essentially you pretty much hit the nail on the dot, thanks man

 

[White Lightning]

On 1/20/2017 at 11:01 PM, Serhal702 said:

@White Lightning It sounds good to me. Others have heard it as well. I went to a tuning seminar for Arc Audio taught by Fred Lynch, and he uses them if I remember correctly. Also I have a year (only) of experience working with Jon Webb as his apprentice in Las Vegas who uses 24db as a starting point to tune active vehicles. Either way, every car is different and sounds different; but in my car, there is a high stable center image maybe 4-6 inches above the dash. All midbass frequencies are above the dash, including most sub bass. Any lower frequency maybe under 35 is all around you, etc. If you sat in my vehicle eyes closed I think it would be difficult to pinpoint anything besides the tweeters since they are on sail panels and the image rainbows a little bit. The 6" speakers in the doors are transparent. Moreover, I have heard more than one vehicle that have 24 db slopes that sounds phenomenal, including Bob Morrow's Honda truck with Audiofrog components (trying not to name drop but thats what Ive heard). I have also heard vehicles that sound good with more shallow slopes.

I have to add that my car isn't perfect it definitely needs more time on the RTA, but after just a little time flattening the frequency response the imaging became much better. Most of my time tuning has been playing with levels, phase, and signal delay, but I postponed it until I can get a couple hours in on an RTA. You did go off topic, BUT i dont mind brother, knowledge is power!

 

Yep, a lot of name dropping for someone asking for advice. Its all good though.

But from the way you described you vehicle's stage and image ... You may need to go back and re-think some things and get rid of that rainbow effect. I'm sure adjusting slopes and phase adjustments could help with that. Sounds like you could be loosing headroom trying to increase your gains "just before clipping" ... sorry, just an observation.

Does sound like you have a very nice setup there ... wish i could get a demo. Where are you located ??? Wish i had time to work on my SQ ride ... 

[Serhal702]

I know not trying to be a douche. I only worked for 1 year at that shop anyways. I'm in Las Vegas right now. For now I think I have a little more headroom for songs that are more dynamic. 

[White Lightning]

My thing is that i never use equipment to set gains. I try and get them as close to ZERO gain as possible. If i need more output power, go to a larger amplifier. 

Hence having a Class A/B 150 wpc amplifier just on my tweeters ... Same on my 5.25" midrange drivers ... Well, its all being wired up when I have time ... LOL