# Before and After



## Exocer (Apr 19, 2006)

Well I didnt want to hijack Bruce's thread so heres my own results :laugh: This forums needs some threads anyway :T 

Sub used : Velodyne DPS-10
Before








After 12 filters








So with the help from the BFD I have a nice little house curve going on. I feel more than happy with the results at this point and haven't changed a thing.

I know its sorta hard to compare the two graphs because of the differences in Y axis settings, but I actually cant find my original data file to go back and change the original "no EQ" graph, so this one will have to do.

Oh and one thing i learned. While setting the phase to 180 degrees may actually flatten things out on your FR, generally speaking, a sub located along the front soundstage will always sound better @ a 0 degree phase as it will be more in phase with the mains. This is something that worked in my situation and i urge others to take note of this. Work with the bumpier FR of the 0 degree phase setting and flatten it with help from the BFD and you will be much happier with the results.


----------



## Sonnie (Apr 11, 2006)

Welcome to the forum Robert! You are our first member to actually post. Thanks! We know we got a long way to go to get crankin'.

You've got this stuff down pat haven't you... Excellent!

You know... I was tinkering around with my phase and it didn't effect my response hardly any. I left it at 0 and my subs are frontstage too.


----------



## chasw98 (Apr 20, 2006)

heres some more before & after:




























My DIY sub at the end. Couldn't have done it without REW & BFD. Thanks Sonnie and John!

Chuck


----------



## Exocer (Apr 19, 2006)

Sonnie, interesting how phase didn't effect things for you. To say switching from 0 to 180 made a slight difference for me would be an UNDERstatement. In the end, 0 just sounded "right" to my ears.

Chasw, Nice response you got there. You've got a nice house curve going on. How does it sound? I actually use two different curves for music and HT on the Velo. (The Rythmik doesn't seem to need EQ at this point in the game, nice little natural curve) My music curve has a much narrower rolloff towards the x-over point. Sounds better for music than HT because I sacrafice some low freq extension when boosting the midrange for music.


----------



## Sonnie (Apr 11, 2006)

Well... it effected it a teeny weeny bit... but just not anything significant in the way of leveling out my response.


Chuck... welcome to the forum. Another excellent job! That's a DIY sub??? Wow! At first glance I thought it was an SVS. Nice work indeed! :T


----------



## chasw98 (Apr 20, 2006)

Sonnie said:


> Chuck... welcome to the forum. Another excellent job! That's a DIY sub??? Wow! At first glance I thought it was an SVS. Nice work indeed! :T


Sonnie........puhleeze! Thats no stinking SVS:nono: Its 6 feet tall and powered with 1200 watts! You probably don't remember but over at AVS you gave me some initial clues about using my BFD. Once I got it set up and working with MIDI it became very easy to dial in the curve I wanted. I went for flattest response with the least amount of filters and no boost over about 8 db anywhere. I keep about 4 or 5 curves stored but mainly use just the generic flat curve for most instances. Nice start for the forum.


----------



## Sonnie (Apr 11, 2006)

SIX FEET TALL! GULP! That's a monster! I bet that is some awesome bass.

I thought that handle/name had a ring to it. Glad you joined us and we hope you hang around and help us grow.


----------



## chasw98 (Apr 20, 2006)

Oh, I'll be around.... If I can talk the wife into it, I want a second one for 2 subs! Yes, I get very nice deepness from it. It will go loud, but I built it to go clean rather than loud. Although the house has rattled on occasion.


----------



## Guest (Apr 20, 2006)

Just curious, the blue line on the graph that starts at say 89db and curves down to 57, is that the 'house curve' that is ideal? Just wondering if where that curve came from?

Thanks,

Mike


----------



## Sonnie (Apr 11, 2006)

Chuck might correct me, but I think that is simply his crossover slope. That response would actually be closer to a flat response.

I hope to get Wayne and Ken to post their info on house curves, which will help everyone understand them much better.


----------



## Exocer (Apr 19, 2006)

Sub Used: Rythmik DirectServo 2.0cu.ft. sealed
















The box does look a lot nicer now since i've gone over the edges with a flush trim bit.
Before: w/ mains @ 80hz crossover. Listening position.








After:
to be continued...

Dont really know if its worth messing with this FR. I'll try to decrease the peaks but i actually liked how things sounded this way.


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

> Sonnie, interesting how phase didn't effect things for you. To say switching from 0 to 180 made a slight difference for me would be an UNDERstatement. In the end, 0 just sounded "right" to my ears.


According to some info Jack Gilvey (I think it was) posted at HTF a few years ago, if your sub is up front near the mains, and if you have 4th order crossovers, 180 degree phase can smooth response considerably around the crossover frequency (about an octave above and below). I tried it, and it did the trick for me, virtually eliminating some serious “sawtooth” response I had in that region.

Other phase values he recommended for selected filter slopes:
1st order, 45 deg.
2nd order, 90deg.
3rd order, 135deg.

Naturally, it gets complicated if you use asymmetrical filters...

Regards,
Wayne


----------



## Exocer (Apr 19, 2006)

Wayne, interesting.
How does a person go about finding which order their filter is? I have no idea what mine is.


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

Sorry for assuming everyone knew... :duh: 

1st order – 6 db/octave
2nd order – 12 db/octave
3rd order – 18 db/octave
4th order – 24 db/octave
Your receiver and sub manuals should say what they have in the specs section. 24 db/octave high and low pass is pretty standard in receivers these days, I think.

Regards,
Wayne


----------



## Exocer (Apr 19, 2006)

lol, its alright. I probably should've known after hanging around these forums for over a year now :laugh: Thanks a lot. I'll check the online manual since my actual manual is MIA.


----------



## Exocer (Apr 19, 2006)

Just a lil update. Things are currently at a 180 degree phase(yes i am a hypocrite ). This setting happened to kill a larger null in the 200-300hz range of my mains, and created a null in the 60-80hz range (again wish I saved those graphs). Moving the sub literally behind the Left main has completely gotten rid of this null.


----------

