Graph Question

[95RCode]

Hi all,

This is my first try at using REW. Very cool program! Not sure if I'm setting every thing up right and would like some opinions if you don't mind. I'll post some graphs and add some comments at the end.

Sub only in front left corner of room(this corner has opening to foyer and hallway)

Sub and mains left front corner

Sub and mains right front corner


Levels on the sub just seem low to me, especially in the left corner. It's a lot smoother there than the right corner. When I try and turn it up I get the clipping detected warning. My system is Onkyo 505, Cadence CSX-12 ( http://www.cadencestore.com/ProductC...&idproduct=396 ) with Beta 20's and a C360 up front and a pair of Athena Bipole surrounds. This is all in a fairly large room, Main listening area is 18 by 18 with cathedral cealing with an attached 10 by 12 open sitting area. Really doesn't sound bad at all but this is used for 98% HT and I would really like more low end umph if you know what I mean.

I realize I have a pretty wimpy sub and may just have to delegate it to bedroom duty and upgrade if I can't get any more than this out of it. Does it appear that I have the program working properly? Thinking about doing a DIY sub anyway. Anyway all comments are welcome.

Thanks,
James

[Wayne A. Pflughaupt]

I agree with pretty much everything you said. Yes, the levels are low, especially in the left corner. Yes, it’s not enough sub for your room if it clips when you turn it up. And yes, it looks like you have the REW program working properly.

Regards,
Wayne

[95RCode]

Thank you so much! I really appreciate the confirmation. Now, how much sub do I really need? Would something like the Rythmik Audio 15" sealed DIY make a major improvement? Or would another ported sub be the way to go. Just not sure how I would detemine what would be enough.

Just to add a dollar amount, could I expect to meet my needs with 5 to 600 dollars, whether it be DIY or ready to go sub. I would it assume it would be ok to use my current sub along with an upgrade.

Regards,
James

[95RCode]

Well, I bit the bullet and have an upgrade sub coming my way. I will post the latest graphs once I receive it and get it broke in. Hopefully will deliver some time in April.

James

[Wayne A. Pflughaupt]

95RCode wrote:

I would it assume it would be ok to use my current sub along with an upgrade.

Not recommended. The problem is, over the limited range of the inferior sub you get twice the output, because the better sub covers that range as well. But at the lowest frequencies you only have the single, superior sub operating all by itself. Thus what you typically find is that overall performance is compromised. Or, like our Moderator brucek is fond of saying, when you use two mis-matched subs, response is “dumbed down” to the lesser sub.

Regards,
Wayne

[95RCode]

Wayne,

Thanks man. Based on that I wont be dumbing down my new sub.

James

[95RCode]

Well, said I would show new graphs when the new sub came in and here they are. I think they look better. Any comments are more than welcome.

Here is the sub only in the right corner:


Sub only in the left corner with opening to foyer:


And finally sub and mains:


As mentioned above my old sub was a Cadence CSX-12, the new one is a AV123 MFW-15. That's the best I could get it trying different speaker and sub locations and different crossovers. One thing that helped out a big dip I had from 100 to 120hz was putting some socks on the speaker rear ports. Is that an acceptable practice?

Anyway this has been really fun so far,
Thanks,
James

[brucek]

Left corner graph looks pretty good. It has a bit of a peak at ~36Hz, but not too bad.

brucek

[95RCode]

brucek wrote:

Left corner graph looks pretty good. It has a bit of a peak at ~36Hz, but not too bad.

brucek

Thanks for the quick response. I think I'll just enjoy it like this for a while and see how I like it. Would that one peak be worth EQing or better left alone? I currently don't have an EQ so there's really not much I could do anyway.

Again thanks,
James

[brucek]

Would that one peak be worth EQing or better left alone?

It's on the edge. I'd see what the response looked like in a few positions on the couch and if the peak moves down in other spots, you may as well leave it be, or even try a small move of the sub.

brucek

[95RCode]

Sounds good. I'll measure from the other listening position in the morning and see how it looks.

Thanks,
James

[Wayne A. Pflughaupt]

If you aren’t going to EQ, then left corner is the location you’ll want to use.

Regards,
Wayne