hi, unfortunately my room dictates both speaker and listening positions. I am getting a ~10bd spike at frequencies 120hz down to 60hz. would a notch filter (image attached) work to attenuate this?
I think it would bu I'm looking at about £100 in part to find out, which isn't a problem if it works.
cheers adie
I think it would bu I'm looking at about £100 in part to find out, which isn't a problem if it works.
cheers adie
Attachments
No, that one is to equalize impedance, not frequency response.
If you want to go this route, you are looking for a parallel notch filter (also called a parallel trap circuit). I think it will probably be fussy to get right and not as precise as you want though.
Most people are using DSP for these kinds of issues now. DSP gives you far greater flexibility, which you are likely to need for this kind of application. The miniDSP units are pretty popular, and if nothing else it's a relatively inexpensive place to start to see if you like the result.
If you want to go this route, you are looking for a parallel notch filter (also called a parallel trap circuit). I think it will probably be fussy to get right and not as precise as you want though.
Most people are using DSP for these kinds of issues now. DSP gives you far greater flexibility, which you are likely to need for this kind of application. The miniDSP units are pretty popular, and if nothing else it's a relatively inexpensive place to start to see if you like the result.
something like this; Buying a miniDSP 2x4 Boxed DSP module? - SoundImports
not sure I want to add a load of electronics in to the signal path but it does get a lot of good reviews.
not sure I want to add a load of electronics in to the signal path but it does get a lot of good reviews.
Yes, that is their base model and should do nicely to give you a feel for the method with a 2-channel setup. It has plenty of capability for the EQing end.
If you decide you need performance, there is a newer HD version, but it's more expensive.
I understand your reluctance to put extra stuff in the signal path, but most people who go this route wind up happy with the results.
Tuning a speaker's in-room response to your liking isn't always straightforward, so the extra flexibility of DSP is nice to have.
If you decide you need performance, there is a newer HD version, but it's more expensive.
I understand your reluctance to put extra stuff in the signal path, but most people who go this route wind up happy with the results.
Tuning a speaker's in-room response to your liking isn't always straightforward, so the extra flexibility of DSP is nice to have.
There's no doubt it complicates the signal path, and it's doing what you described in the digital/analog domains. There are other solutions to the hardware end that cost more and do more (DDRC-22D, OpenDRC-DI, etc. which operate on the digital side). But I was trying to suggest something cheap that could give you a feel for what the equalization can do.
Some form of DSP is likely to simplify the quest to tame your bass, even if it's only an interim experiment.
Assume for a moment that it messes up your imaging or other things, but lets you try 20 different equalization settings to get the bass just the way you want it. That correction curve can then be used to try to produce the passive response shaping circuit you were originally asking about. It'll go a lot more smoothly if you know exactly what you want.
The circuit will likely require modeling as well. It's not something where a cookbook answer is likely to provide an accurate solution in one go. If you don't have a lot of crossover parts lying about and you're dealing with big inductors, tweaking things can get expensive.
Or you may decide that the "10 dB spike" isn't that offensive after all. You didn't give many details about your response anomaly, so I'm not sure if you are describing something that's in your face or if you are just trying to improve a plot. 10 dB variations in in-room response in the bass range are common depending on how it's measured. In some rooms, smooth response is only possible with a lot of care in setup, large damping solutions, etc. (or DSP room correction). Even the reviewers in the Stereophile magazine have some pretty rough in-room plots at times, but they typically say they sound a lot better than they measure.
Anyway, all of this is just one person's opinion, and maybe you'll get luckier than I do when it comes to response tweaks. For my projects, I appreciate having multiple amps, active crossovers, etc. in the early phases of design because it speeds things up tremendously and lets you know when things that seemed like good ideas in theory aren't going to pan out.
Some form of DSP is likely to simplify the quest to tame your bass, even if it's only an interim experiment.
Assume for a moment that it messes up your imaging or other things, but lets you try 20 different equalization settings to get the bass just the way you want it. That correction curve can then be used to try to produce the passive response shaping circuit you were originally asking about. It'll go a lot more smoothly if you know exactly what you want.
The circuit will likely require modeling as well. It's not something where a cookbook answer is likely to provide an accurate solution in one go. If you don't have a lot of crossover parts lying about and you're dealing with big inductors, tweaking things can get expensive.
Or you may decide that the "10 dB spike" isn't that offensive after all. You didn't give many details about your response anomaly, so I'm not sure if you are describing something that's in your face or if you are just trying to improve a plot. 10 dB variations in in-room response in the bass range are common depending on how it's measured. In some rooms, smooth response is only possible with a lot of care in setup, large damping solutions, etc. (or DSP room correction). Even the reviewers in the Stereophile magazine have some pretty rough in-room plots at times, but they typically say they sound a lot better than they measure.
Anyway, all of this is just one person's opinion, and maybe you'll get luckier than I do when it comes to response tweaks. For my projects, I appreciate having multiple amps, active crossovers, etc. in the early phases of design because it speeds things up tremendously and lets you know when things that seemed like good ideas in theory aren't going to pan out.
thanks for taking the time mate, hope my previous posts didn't come across as ungrateful. like you say, its just a tool that can only help in the long run. if I like what it does for the bass then I can use that knowledge.
its certainly not spoiling my listening and is only noticable on ~30% of songs anyway. I know I was kidding myself thinking I might get a quick fix.
thanks again dude, adie
its certainly not spoiling my listening and is only noticable on ~30% of songs anyway. I know I was kidding myself thinking I might get a quick fix.
thanks again dude, adie
Your posts were fine. No offense taken. Sometimes it takes a few rounds of messages to figure out where someone is in their thought process and exactly what they're after.
I think there are multiple ways to deal with your bass issue. It's just a matter of figuring out which one is most pleasing to you.
I think there are multiple ways to deal with your bass issue. It's just a matter of figuring out which one is most pleasing to you.
Acoustic solution to your problem
Have you ever thought about acoustical treatments of your room? I just finished my listening room and I had the same problem. My room is 6 by 6 meters. And the room sufferd from a zooming noise in the low region because of standing waves.
I bought 6 basstraps from i4studio. This is a webshop based in holland. And I put 3 of them in the corners behind my speakers. And really it solved all of my problems. They ship to England. And they are not that expensive.
If you need more damping, you could also place them in the other corners behind your listening seat.
See the picture i have attached.
Regards edwin
Have you ever thought about acoustical treatments of your room? I just finished my listening room and I had the same problem. My room is 6 by 6 meters. And the room sufferd from a zooming noise in the low region because of standing waves.
I bought 6 basstraps from i4studio. This is a webshop based in holland. And I put 3 of them in the corners behind my speakers. And really it solved all of my problems. They ship to England. And they are not that expensive.
If you need more damping, you could also place them in the other corners behind your listening seat.
See the picture i have attached.
Regards edwin
