This is why I love headphones. 😀 No room.
It is full-range as well, so fits the topic marginally. 😉
It is full-range as well, so fits the topic marginally. 😉
Well, I haven't heard the perfect speakers and perfect room that allows anyone sitting anywhere having the exact same experience either.
I haven't heard DRC making it worse in my case.
Even when not using DRC, the experience of someone sitting "in the sweet spot" will be different than sitting all over the room.
I prefer to look at it this way:
There was a problem with the room's acoustic before. All over the place.
DRC fixed my listening spot,
and nope, it didn't make it worse than before for someone sitting near me.
The major changes in frequency response observed with small changes in location are due to room reflections so it is not possible fix this without creating a ridiculously small sweet spot. The good news however is that in the case of good symmetry regarding room/speaker placement with enough "breathing room" around the speakers, these reflections are basically "tuned out" by our hearing mechanism. The exception would be below the schroeder freq where the speakers and room are perceived to be acting more like one system.
Frequency dependant windowing means we look at the freq response based on an impulse response whose window length is getting shorter with increasing freq (one cycle of 20hz lasts 50ms while one cycle of 20khz lasts .05ms). With an appropriate window length for a given room, the freq response based on this type of windowed impulse response will be that of only the direct sound above a certain freq. This is the frequency response that we invert with DRC.
Put another way, in choosing a freq dependant windowing length, you are choosing the size of your sweetspot.
Frequency dependant windowing means we look at the freq response based on an impulse response whose window length is getting shorter with increasing freq (one cycle of 20hz lasts 50ms while one cycle of 20khz lasts .05ms). With an appropriate window length for a given room, the freq response based on this type of windowed impulse response will be that of only the direct sound above a certain freq. This is the frequency response that we invert with DRC.
Put another way, in choosing a freq dependant windowing length, you are choosing the size of your sweetspot.
Maybe we should invite Mr. Jan Didden to continue this conversation on this thread:
http://www.diyaudio.com/forums/full-range/275730-convolution-based-alternative-electrical-loudspeaker-correction-networks.html
Let's keep the OP and his room to himself 😉.
http://www.diyaudio.com/forums/full-range/275730-convolution-based-alternative-electrical-loudspeaker-correction-networks.html
Let's keep the OP and his room to himself 😉.
I know that thread. Intersting tool. There are other tools to flatten your speaker. What does that have to do with room correction and the fact that RC can only correct at the sweet spot and most of the time makes it worse outside the sweet spot? Or did we just change the subject? 😉
Jan
No intention of changing the subject, just a continuation elsewhere 🙂
You can also drop in on my own thread, which covers quite a lot of this stuff already: http://www.diyaudio.com/forums/full-range/242171-making-two-towers-25-driver-full-range-line-array.html
The OP has made it clear not to be on the path of digital room correction, although he expressed some interest in it. So I do not see a good enough reason to go into it any further on this thread. But I can't change my own experience which contradicts your original statement. So that's why I suggest to move it elsewhere. If you want of coarse.
You can also drop in on my own thread, which covers quite a lot of this stuff already: http://www.diyaudio.com/forums/full-range/242171-making-two-towers-25-driver-full-range-line-array.html
The OP has made it clear not to be on the path of digital room correction, although he expressed some interest in it. So I do not see a good enough reason to go into it any further on this thread. But I can't change my own experience which contradicts your original statement. So that's why I suggest to move it elsewhere. If you want of coarse.
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Thanks, Jan. I hope that helped. I'll be more than happy to continue the discussion over in the other thread as per wesayso's suggestion. See you guys over there 🙂.
Anyway, In my first listening room, I set up along the long wall with the sofa against the wall and a tapestry above the sofa. Measurements were slightly tricky, but like wesayso, I ultimately got good results. However, I also think symmetry is important so I agree with also considering the other arrangement that has been suggested. Good luck!
--Greg
Anyway, In my first listening room, I set up along the long wall with the sofa against the wall and a tapestry above the sofa. Measurements were slightly tricky, but like wesayso, I ultimately got good results. However, I also think symmetry is important so I agree with also considering the other arrangement that has been suggested. Good luck!
--Greg
@wesayso: So that is you with those big tower line arrays! I have read that thread before, and was very impressed. I toyed with the idea of line arrays, but it seems that a lot of people do add some kind of equalization, and I would like to keep it simple... I am also not sure if a line array would work in my room.
Regarding the previous active configuration of the speaker, it's not that it didn't sound good, the problem was simply that the electronics broke a couple of times, and a repair always meant to take the active units out and ship them to Germany (from the US) for repair... that got too costly, and thus I gave up on the active part.
To get back to my room now, I have been thinking that maybe doing some acoustic treatment on the ceiling would be a good start. It could be made somewhat more visually pleasing, aka wife-friendly.
I think the biggest problem in the room is all that echo. If I clap, it's like I am using a reverb or something...
An acoustic treatment of the ceiling might be a lot of work, but could help, don't you think? I am also sick of hearing the TV of my neighbors above me... it might help "deaden" that too.
Regarding the previous active configuration of the speaker, it's not that it didn't sound good, the problem was simply that the electronics broke a couple of times, and a repair always meant to take the active units out and ship them to Germany (from the US) for repair... that got too costly, and thus I gave up on the active part.
To get back to my room now, I have been thinking that maybe doing some acoustic treatment on the ceiling would be a good start. It could be made somewhat more visually pleasing, aka wife-friendly.
I think the biggest problem in the room is all that echo. If I clap, it's like I am using a reverb or something...
An acoustic treatment of the ceiling might be a lot of work, but could help, don't you think? I am also sick of hearing the TV of my neighbors above me... it might help "deaden" that too.
Hi drtebi, with respect to your room... I looked through the thread and did not see if you have any tools to measure the acoustics of your room? i.e. a PC, measurement mic, mic preamp, and free software like REW - Room EQ Wizard Room Acoustics Software
Just saying as this would help identify the issues, such as the echo you are hearing. Using REW's Energy Time Curve (ETC) display will help identify quantity and where the reflections are located. Then with a heavy blanket or two, you can temporarily hang those where the reflections are located and verify with measurement that the reflections are dampened (or diffused depending on how lively would want to keep the room). Then you can DIY or purchase acoustic treatments with the knowledge that it will take care of the problem and eliminate guesswork and potential expense of not covering the right reflection points...
Just saying as this would help identify the issues, such as the echo you are hearing. Using REW's Energy Time Curve (ETC) display will help identify quantity and where the reflections are located. Then with a heavy blanket or two, you can temporarily hang those where the reflections are located and verify with measurement that the reflections are dampened (or diffused depending on how lively would want to keep the room). Then you can DIY or purchase acoustic treatments with the knowledge that it will take care of the problem and eliminate guesswork and potential expense of not covering the right reflection points...
@drtebi, yes indeed, that's the way I manipulate those towers. I chose to build them because they fit my plans for my room the best. It was either horns or line arrays for what I wanted to obtain. My girl didn't like the look of horns (I love their look) and accepted the arrays due to their small footprint and she wouldn't allow me to have the speakers out in the room. But the way I did it, they sure need EQ correction. But on the other end they by-passed two mayor reflections (floor and ceiling).
I'm figuring your room is still relatively empty? Lots of hard surfaces? OB speakers need quite a bit of room. Consult with your wife what you're allowed to do. Treatment will help.
I use treatment in the shape of damping panels to get my non symmetric room sound more symmetrical. The reason for me was that I wanted my speakers to double as a HT set for watching movies on TV. I add more sound afterwards (ambient speakers) to make up for the damping, but manipulate that as if I were listening in a bigger room.
Before you make any plans try and optimise what you've got. Read the above post and do some measurements to be able to see what that is. There are always reasons why it sounds like it does. Experiment with some cheap damping materials (like the blanket mentioned by Mitch) and learn what it does for your room. I'd definitely think about adding drapes for the window side. Figure out what you want first. Look at speaker types only after you know what that is you want your speakers to do.
I'd suggest reading some treads on the differences between speakers and their directivity. For your room, from what I've seen at least with the big fire place I'd go for horns. I wouldn't have a problem with arrays either, but it might take more work to get them to play nice with the room as they are way less directional horizontally. The reason for the horns is less early reflections to deal with.
I count myself lucky that I was allowed to build my huge monsters with wife approval. But they still fit on a sheet of A4 size paper in floor space!
Another note: if you hear your neighbours, be sure they will also hear you with the wrong speaker choice.
I'm figuring your room is still relatively empty? Lots of hard surfaces? OB speakers need quite a bit of room. Consult with your wife what you're allowed to do. Treatment will help.
I use treatment in the shape of damping panels to get my non symmetric room sound more symmetrical. The reason for me was that I wanted my speakers to double as a HT set for watching movies on TV. I add more sound afterwards (ambient speakers) to make up for the damping, but manipulate that as if I were listening in a bigger room.
Before you make any plans try and optimise what you've got. Read the above post and do some measurements to be able to see what that is. There are always reasons why it sounds like it does. Experiment with some cheap damping materials (like the blanket mentioned by Mitch) and learn what it does for your room. I'd definitely think about adding drapes for the window side. Figure out what you want first. Look at speaker types only after you know what that is you want your speakers to do.
I'd suggest reading some treads on the differences between speakers and their directivity. For your room, from what I've seen at least with the big fire place I'd go for horns. I wouldn't have a problem with arrays either, but it might take more work to get them to play nice with the room as they are way less directional horizontally. The reason for the horns is less early reflections to deal with.
I count myself lucky that I was allowed to build my huge monsters with wife approval. But they still fit on a sheet of A4 size paper in floor space!
Another note: if you hear your neighbours, be sure they will also hear you with the wrong speaker choice.
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I would really like to take some measurements. I have a mic (a general purpose one, not specific for room measurement), and plenty of computers... I will look into the software you recommend, and hopefully can get this arranged. Any further pointers would be appreciated.
You probably want to invest in a purpose designed mike - although you can gat a bit spendy if you like, the budget ones are much cheaper than inappropriate treatment materials
I think you're right, my wife really needs some treatment 🙂 Just kidding! I know what you mean, and will experiment further.
I have started some experiments with the new arrangement as suggested in the beginning of this thread. I have gotten some interesting results, please read on, I am curious about your opinions.
So first I rearranged the speakers as suggested. This definitely did one thing: It "opened up" the sound. Mids and highs sounded more clean.
But my main concern, the mid-bass, was still an issue. I should add that I play a bit of bass myself, my best childhood friend is a bass player, I played drums in many bands... so I do have a pretty good idea of what bass should sound like.
The speakers seem to still deliver the very low notes very well, like a kick drum. But bass sometimes completely disappears! I can still make it out due to the harmonics, but the actual notes are almost gone. I took my bass and played along, and it turns out that the notes missing the most are around an open A, which should be around 55 Hz.
Then I had an idea... I took another pre-amp, connected it to the rec-out of the main pre-amp, and connected the output of that second pre-amp to my bass guitar amp:
This allowed me to carefully "mix-in" the SWR bass amp. I set treble and mids to zero, and added a touch of bass. This is not a low-pass filter... but good enough for experimenting.
This made a huge difference! Now exactly those notes that had disappeared before came back into the mix. I really liked how it sounded then.
The curious thing however was, that I had the bass amp initially fairly close to me (about a meter in front of me), and when I moved it in-line with the tower speakers, I noticed that that mid-bass started to disappear again. It still sounded better, but some "umph", I mean that good-sounding "umph", was missing.
Then I decided to move my listening position a bit closer to the speakers, and when I was in a equilateral triangle (all distances the same), running only the tower speakers, the mid-bass sounded better. Adding the bass guitar amp helped a bit more, although it felt almost unnecessary.
I am not sure how exactly to interpret these findings. I am definitely thinking that a proper subwoofer might get me what I want, although I do want to find a solution where it's not so dependent of the listening position. I will look into measuring now, so I can approach this a bit more scientifically.
What do you think?
Sounds like you're now running into issues of room modes / listening position - if you were to walk around the room with system playing. I'd be surprised if you didn't find spots where the missing bass blossomed, then disappeared only a step or two away.
I think you could be a candidate for at least a couple of smaller (8-10") woofers for distributed bass - I've found they often work best located asymmetrically, and well away from the mains. Try the front left corner alcove between the fireplace and the window, and beside the door on right side of the room (appropriately sized they can make a sturdy enough side table and cocktail shaker).
How heavy is the door? You might also want to consider upgrading it to a solid core unit, and adding weather stripping for a full seal.
I think you could be a candidate for at least a couple of smaller (8-10") woofers for distributed bass - I've found they often work best located asymmetrically, and well away from the mains. Try the front left corner alcove between the fireplace and the window, and beside the door on right side of the room (appropriately sized they can make a sturdy enough side table and cocktail shaker).
How heavy is the door? You might also want to consider upgrading it to a solid core unit, and adding weather stripping for a full seal.
Yes, as chrisb has said, this is pretty typical room behavior. Distributed bass would likely help from what I've heard but of course it would also mean a more complex setup.
Since it seems like you're going to be sitting fairly far from the speakers, you might also want to consider dipole speakers since compared to monopole speakers there will be less "room sound" especially in the problematic bass region (less exitation of room modes). With an area rug and curtains to control mid/high freq reflections, you might really be in business.
Since it seems like you're going to be sitting fairly far from the speakers, you might also want to consider dipole speakers since compared to monopole speakers there will be less "room sound" especially in the problematic bass region (less exitation of room modes). With an area rug and curtains to control mid/high freq reflections, you might really be in business.
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fair enough, but simply put, dipoles and open baffles no matter how well they can sound, don't automatically garner high WAF values - certainly never have for me 😱
The door is solid quarter-sawn oak:
Old Classroom Door Restoration Project - by DrTebi @ LumberJocks.com ~ woodworking community
I love that door, 🙂
I took the experiment one step further.
The bass guitar amp produced lots of noise. So I opened it up, disconnected the driver, and ran a separate wire from the speaker out of the box. I then setup my Nakamichi PA-5 power amp, and connected that to the speaker via the same setup with the separate pre-amp.
Now I was missing tone controls, so I made a very crude low-pass filter by simple turning the bass-amp speaker 90 degrees towards the floor... so that the speaker sits directly on the floor.
Surprisingly, that worked out really nice. The bass is really nice now, and all noise is gone (due to the better amp). Even at very low volume it's great.
I want to find out now, how this setup will sound with the original speaker placement. Fact is, that the new arrangement is really not very convenient, and I don't think the wife approves of it much.
She knows about my idea to build new speakers though, and it seems that she wouldn't mind an open baffle design; she is rather not too fond of the new speaker/listening position setup, and I am not too crazy about it either.
So I may come back to the idea of building an open baffle with subwoofers. That's kind of what I had in mind for the Nakamichi PA-5 anyway, I am thinking active cross-over, so that I can control the open baffle and subwoofer separately.
My biggest concern is, whether an open baffle would sound good when placed next to the fireplace. I could pull it out so that the driver is as far out as the fireplace, or even a few inches further.
I haven't checked out dipole subwoofers yet, got some more reading to do now...
The bass guitar amp produced lots of noise. So I opened it up, disconnected the driver, and ran a separate wire from the speaker out of the box. I then setup my Nakamichi PA-5 power amp, and connected that to the speaker via the same setup with the separate pre-amp.
Now I was missing tone controls, so I made a very crude low-pass filter by simple turning the bass-amp speaker 90 degrees towards the floor... so that the speaker sits directly on the floor.
Surprisingly, that worked out really nice. The bass is really nice now, and all noise is gone (due to the better amp). Even at very low volume it's great.
I want to find out now, how this setup will sound with the original speaker placement. Fact is, that the new arrangement is really not very convenient, and I don't think the wife approves of it much.
She knows about my idea to build new speakers though, and it seems that she wouldn't mind an open baffle design; she is rather not too fond of the new speaker/listening position setup, and I am not too crazy about it either.
So I may come back to the idea of building an open baffle with subwoofers. That's kind of what I had in mind for the Nakamichi PA-5 anyway, I am thinking active cross-over, so that I can control the open baffle and subwoofer separately.
My biggest concern is, whether an open baffle would sound good when placed next to the fireplace. I could pull it out so that the driver is as far out as the fireplace, or even a few inches further.
I haven't checked out dipole subwoofers yet, got some more reading to do now...
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