Is this response curve OK??

[cruzmisl]

Hi All,
I tried tinkering with my DSP 30 to try and get my response as smooth as possible. It took about 10 bands of EQ to get it where it's at. The maximum gain I have on any of them is +5. Any thoughts? Is the response supposed to follow the blue line or the 75dB reference line?

This is before


This is after,


and a comparison,


Thanks for any tips,

Joe

[Wayne A. Pflughaupt]

The maximum gain I have on any of them is +5.
Any thoughts? Is the response supposed to follow the blue line or the 75dB reference line?

Blue line. Did you have the mains turned off during the sweeps? It looks pretty good, but it is kinda flat. After listening to some programming, if you think it sounds lacking you might try a house curve. You might be able to accomplish that with the DSP-30’s shelving filter.

Regards,
Wayne

[cruzmisl]

Thanks Wayne. I did a bit of research on the house curves but have to look into it more. I'm pretty sure the DSP30 will have no issue with that.

[cruzmisl]

Wayne, I read the house curve article and it really focuses on the BFD without a shelving filter. Any tips on how to do it for an EQ that has a shelving filter such as mine?

[Wayne A. Pflughaupt]

Hmm... Well, you’d want a low shelving filter – but I guess you already figured that out. Don’t know exactly how the DSP 30 works, but I did see in the specs that the shelving appears to be pretty flexible, with adjustable Q. I’m not really sure how Q functions with a shelving filter, but I’m guessing it affects how broad or steep the action is. You’ll have to experiment with that – REW can easily give you a visual of what’s happening.

As far as actual adjustment, you’d first determine the slope you want using the 100 Hz – 30 Hz sinewave test I described (or whatever upper and lower frequency markers you decide to use). Ultimately that’s what you’re shooting for, 30 Hz at 0 dB, 100 Hz at –6 or –8 dB, or whatever your target is.

Hopefully the turnover frequency is adjustable – otherwise the filter will be of no use. Set the turnover frequency down low, say 25 Hz, possibly lower. This is because typically response will actually “hinge” at a higher frequency than the setting once you cut the filter. At least, that’s the way it usually is with analog filters. Digital filters – haven’t used one, you’ll just have to see. I have a feeling the Q setting may also affect how quick response changes at the turnover frequency – again, use REW to see.

So basically, cut the filter for the amount you want 100 Hz to be attenuated, then play with the turnover frequency and Q settings until response starts hinging downward at 30 Hz or so.

That’s about the best I can tell you – hope it helps.

Regards,
Wayne