DIY Sub - Started Today, Finally!

[ThomasW]

Didn't feel like moving the 150lb box all over the living room last night.

Furniture dolly ...:wink:

[dyazdani]

Furniture dolly ...:wink:

Yeah, I think we had this discussion once before. I always forget to pick one up or build one. :M

I may drop by the HW store and see if they have some casters. I've got enough 2x4s to throw something together.

[dyazdani]

I played with the BFD last night, subwoofers only and got filters adjusted for "reasonably" flat response. I was not all that impressed with the sound so I did some further experimenation at lunch today.

It seems as though there is somewhat of a "dead spot" at the listening position. You can movea couple of feet left or right and the bass pours out - too much, more than likely. At the center of the room (width-wise) however, the bass is much more tame, relatively speaking.

Any ideas on what to do? I've tried moving forward and back along the [length-wise] center, doesn't change near as much as moving side to side.

I also have a question on the measurement process. I tested each sub separately and developed filters for each. I also set their outputs to the same level. I then played both subs simultaneously to set the overall level from the processor.

Today, I will repeat the process, but using a signal through the pre/pro so as to test the integration with the mains. Is there a better way to do it?

[ThomasW]

A room null is the sub's way of telling you it needs to be moved....:wink:

You might want to work on one sub at a time. Trying to dial in to completely different types of sub is going to be trickey.

Do you have a floor plan that you can post?

[dyazdani]

A room null is the sub's way of telling you it needs to be moved....:wink:

Thought so, just running out of places to put one... Do you think I should resort to putting the sub at the listening position?

You might want to work on one sub at a time.

That is what I did, just wanted to make sure that was the right way to go.

Do you have a floor plan that you can post?

Yes, I will do so when I get home...

Thanks for the help...

[ThomasW]

Do you think I should resort to putting the sub at the listening position?

That's a good way to find the best position for the sub. Potential issue is that you may find it belongs where some immovable object now lives..:wink:

[dyazdani]

That's a good way to find the best position for the sub. Potential issue is that you may find it belongs where some immovable object now lives..:wink:

That's my fear too :cry:

[dyazdani]

Here is a true floorplan, from the blueprint... I highlighted the room, you can see that it is open to the rest of the house on the left...

I also have a diagram I threw together that shows the approximate layout of the equipment, a 3D model, and some real photos...they are a little old (prior to painting, etc), but should suffice.

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[ThomasW]

Okay, now when are you going to start building the addition for the HT?......:wink:.....just kidding.

I'd put the DIY sub in the left corner and the BagEnd behind the sofa...and now I'm not kidding ....:B

[dyazdani]

Okay, now when are you going to start building the addition for the HT?......:wink:.....just kidding.

I'd put the DIY sub in the left corner and the BagEnd behind the sofa...and now I'm not kidding ....:B

When you say behind the sofa - you mean centered in the room or along the well (left side of the last picture, below the Maggie)?

This is treading in the low WAF zone...

Oh, and how did you arrive at the above conclusions, for future reference?

[ThomasW]

Placement is experimentation.

Moved the DIY away from the sliding glass doors.

Putting the BagEnd behind the sofa might even out the null.

For some of us this is a Zen thing. So I make wild guesses and if it works I look like a genius. If it doesn't I rationalize by saying it wasn't meant to be..... Doh! :B

[dyazdani]

Placement is experimentation.

Moved the DIY away from the sliding glass doors.

That was my concern with its current placement too. Only issue is that there is no other place along the front wall except right next to the BagEnd (currently) and it didn't seem to like it there.

Here is the response at the moment...with my mains included, so it doesn't actually follow the curve on the upper end.

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[ThomasW]

The idea is simply to experiment.

Try putting the BE behind the sofa, or at one end of the sofa then check the FR when both subs are operating.

If it looks amazing then be prepared to do something very nice for the wife.... :B

[dyazdani]

Didn't have time to move things around tonight, but I did adjust on the filters...

DIY Sub -

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Bag End -

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[dyazdani]

The measured response doesn't look awful though still not to my liking, but I'm just not all that impressed yet. Maybe I got used to the "old" sound with just the BagEnd and now that I'm changing everything, it's just different. Seems like there is not as much output from either sub now, maybe I'm just crazy from listening to test tones for 3 days :crazy:

I'll have a lot more time to do the proper experimenting with the location this weekend. I'm not giving up, just trying to get by with the minimum until I have more time to tweak.

[dyazdani]

I found two other interesting things last night, well, one bonehead mistake, I had the input level button on the DIY sub's channel set to +4 rather than -10.

The other thing is that I havd a couple of high gain boost filters, I think they were killing the sub's output maybe. The sub had a very strange sound to it - almost like the cone was being restricted, very weak and "twangy." I put the BFD in bypass and it tightened up and increased in output dramatically.

Still so much work to do... :E

[dyazdani]

Thomas,

I got the subs moved around like you suggested and it seems to have helped greatly. That plus the break I took for a day let my ears "re-calibrate." I will re-measure and set up the BFD again this weekend.

I feel much better about the whole thing now!

[ThomasW]

Good news .... :T

Playing with low frequency test tones is weird since it takes a while before they get tiring....so be careful not to toast your ear.... 8O

[dyazdani]

Playing with low frequency test tones is weird since it takes a while before they get tiring....so be careful not to toast your ear.... 8O

I don't know :scratchhead:

My wife gets tired of it pretty quickly :rofl:

Thanks for the help ;x(