Is it wise to pre eq a horn resonance?

[Samps]

I've seen in some of Josh's write ups some eq suggestions for bass horns. So is it a good idea to eq out horn resonances before putting in room and adjusting? Originally I thought maybe a big peak might help if the room had a dip at that frequency, but now I'm curious if that resonance is bad regardless of the room. Obviously it's best to only use a horn within its smooth bandwidth but taming the first peak can stretch an extra 20hz.

 

So do I eq down that first peak before the room, or wait to see what the room gives me?

[SME]

It mostly doesn't matter.  How big is the room and how tall is the ceiling?  What application?

[Samps]

A BFM THT. Room is 30x14x8.5. There is a big peak at ~80hz natively.

 

This is a nearfield sub so that peak is a little more in your face. A low pass fixes it or a big 10db cut fixes it.

 

I'm interested if it would be more natural to eliminate that peak prior to room eq. Currently the room eq would only require about 5db of cut.

 

Does the natural peak have extra noise that wouldn't show up in a simple frequency sweep? Like, 'maybe it would sound better to have a dip there than leave some of that peak? Do those peaks contain more distortion than the rest of the bandwidth?

[Ricci]

I would suggest fixing the response prior to the room. I used to think it was pointless until placed in room and measured, but over the years it seems like it can be heard even though you may have a flat measured response at a listening position or two. The one that really seemed to be audible was the DTS-10. It sounded much better with the 54Hz peak notched out prior to placing it in room vs EQing for a listening position or two after. It sounded better even if the response ended up with a bit of a notch near that area in room at the LP. Despite what may have been EQ'd and measured flat at the LP a smearing or ringing could be heard. I'm not the only one to report this either. In the case of the DTS-10 this area would ring for a long time. I don't know if a THT has any areas of stored energy or not. I've never seen measurements of group delay or decay from one. Just because there is a response peak does not mean that it necessarily rings excessively.

 

 Typically a response measurement is a single point measurement or perhaps a couple  of points in a very small area inside of a very large 3 dimensional space. While the response may appear to have equal energy at a single point location the raw response of the system sees the entire space and often that peak or ringing will manifest in large areas of the rest of the space and becomes apparent in the signal start and decay characteristics. This appears to be audible to some extent at least to me versus what you see on a basic frequency response measurement.

[Samps]

Thanks Josh. I tried both options last night and IMO taking out the peak first sounded better, even though the response looked worse.

[radulescu_paul_mircea]

Because of the way the brain-ear system works they sort of filter out the room's influences on sound and they tend to hear the source as it is. So even though you have a flat indoor response, you might be very used with the sound of your room and the brain deletes the effects of the room to the original source and any problems that the speaker has in free anechoic field you will hear them even though your measurements at the listening position shows nothing.

[SME]

Because of the way the brain-ear system works they sort of filter out the room's influences on sound and they tend to hear the source as it is. So even though you have a flat indoor response, you might be very used with the sound of your room and the brain deletes the effects of the room to the original source and any problems that the speaker has in free anechoic field you will hear them even though your measurements at the listening position shows nothing.

 

My guess is that this is true to some extent but not as true for bass as for mid.  But it really depends on the room size and other things like that.  And it also depends on exactly how you do your EQ corrections.  In principle, you should have no problem EQing the resonance out in-room if it's important, but I guess it's harder to recognize the resonance for what it is without having data at multiple room locations and so on.