+1
I think it is a great waste of time to try to help people with this kind of thread unless there are measurements posted.
It shows disrespect to the forum for an OP not to go to that tiny (and free) bit of effort beforehand.
B.
I don't need to. Have a look at what was said again - I'm disagreeing with your subjective assessment, based on my experience.
I think EQing the big peaks down improves the sound a lot. It certainly does not sound "poor" in my opinion. Is it better with proper acoustic treatments? Certainly.
Is it better than no EQ at all? Again, certainly.
Scott, the seats were sofas around the edge of the room. 5/6 of them showed a peak of about 10dB at 40Hz, and another was pretty flat in that region. Adding the EQ dip fixed 5/6 of the seats, with the last one having a dip there.
Peaks are worse than dips, and it was 5 seats better vs 1 seat worse, so I deemed that a worthwhile bit of EQing.
Chris
For domestic rooms, enormous variation exists in the bass curve and, aside from using the error of using tuned boxes, is related to room resonances. Depends of course on speaker location and listening location. Enormous and hard to predict, and some boosts and some cuts.
For a given seat, BY MEASURING you can find good sub locations for that seat* which seem to result in a good curve. For sure, nobody ought to deny the value of EQing to fine-tune from that point. Many here do it.
But room treatment goes to the heart of the problem of modes. The only problem being, adequate room treatment is simply unfeasible at home, at least if you have a spouse, no fortune to spend, and/or care about appearance.
B.
*I get substantial changes depending on the door to a clothes closet being open or closed. But that particular door and closet are located at a mode hot spot.
For a given seat, BY MEASURING you can find good sub locations for that seat* which seem to result in a good curve. For sure, nobody ought to deny the value of EQing to fine-tune from that point. Many here do it.
But room treatment goes to the heart of the problem of modes. The only problem being, adequate room treatment is simply unfeasible at home, at least if you have a spouse, no fortune to spend, and/or care about appearance.
B.
*I get substantial changes depending on the door to a clothes closet being open or closed. But that particular door and closet are located at a mode hot spot.
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I see it both ways, but I gotta say that often times I see folks posting huge freaking expensive systems (not me) with no room treatment. That's just asinine.
Since this a DIY forum the construction of room treatment goes hand in hand if you ask me. And the first dollar spent should be Everest's "Acoustics". I am no expert but am very familiar with treatment approaches, although I have not done this to my room YET. As fate would would have it, this thread got me researching limp mass vinyl and FINALLY found a supplier near me. Shipping on acoustic material is the largest cost. (single 4' wide role of 25' of limp mass vinyl is 100lbs and insulation board is large)
Some things I picked up over time and no time to research cites but maybe this will inspire someone. From memory, you want to approach it like this:
1. Room should be no less than 1,500ft3. Anything smaller is nearly impossible to treat properly.
2. Build limp mass absorbers to treat offending LF modes. I like this calculator: http://www.bobgolds.com/Mode/RoomModes.htm and then this for design: https://www.gearslutz.com/board/bas...etc/743040-tims-limp-mass-bass-absorbers.html These must be place in their proper location but general rule is all corners of the room.
3. Reduce reverb time STC60 by broadband absorption with rigid fiberglass (Owens 703).
4. Fine tune for early reflections at sitting position.
All this being said, the approaches are hotly debatable and there are styles. IE: LEDE What do LEDE rooms have in common with Concert halls? and RFZ How to Build a "Reflection-Free Zone" to Treat Early Reflections and more!
Since this a DIY forum the construction of room treatment goes hand in hand if you ask me. And the first dollar spent should be Everest's "Acoustics". I am no expert but am very familiar with treatment approaches, although I have not done this to my room YET. As fate would would have it, this thread got me researching limp mass vinyl and FINALLY found a supplier near me. Shipping on acoustic material is the largest cost. (single 4' wide role of 25' of limp mass vinyl is 100lbs and insulation board is large)
Some things I picked up over time and no time to research cites but maybe this will inspire someone. From memory, you want to approach it like this:
1. Room should be no less than 1,500ft3. Anything smaller is nearly impossible to treat properly.
2. Build limp mass absorbers to treat offending LF modes. I like this calculator: http://www.bobgolds.com/Mode/RoomModes.htm and then this for design: https://www.gearslutz.com/board/bas...etc/743040-tims-limp-mass-bass-absorbers.html These must be place in their proper location but general rule is all corners of the room.
3. Reduce reverb time STC60 by broadband absorption with rigid fiberglass (Owens 703).
4. Fine tune for early reflections at sitting position.
All this being said, the approaches are hotly debatable and there are styles. IE: LEDE What do LEDE rooms have in common with Concert halls? and RFZ How to Build a "Reflection-Free Zone" to Treat Early Reflections and more!
Hi Zwiller,
The problem with basstraps covered with 'deadsheet' is that they are not very efficient below 100Hz. You can increase their efficiency by using stiff membranes (from plywood for instance) that will raise the Q.
1/4 WL traps in the form of multiple panel absorbers along the walls, if done correctly of course, behave like open-end-closed-end tubes that have their absorption peak at 1/4WL and 3/4WL. This method was introduced by Tom Hidley, in early eighties. Today this method is still used in many reference control rooms around the world.
Regards,
Djim
The problem with basstraps covered with 'deadsheet' is that they are not very efficient below 100Hz. You can increase their efficiency by using stiff membranes (from plywood for instance) that will raise the Q.
1/4 WL traps in the form of multiple panel absorbers along the walls, if done correctly of course, behave like open-end-closed-end tubes that have their absorption peak at 1/4WL and 3/4WL. This method was introduced by Tom Hidley, in early eighties. Today this method is still used in many reference control rooms around the world.
Regards,
Djim
Thanks Djim. I went hunting for cites but cannot find anything reliable and would love to see anything you have. I was under the impression that 1/4WL traps work but were old school since they are so big. I also thought that if a limp mass absorber was "tuned" (I think it then becomes a diaphramatic?) and built accordingly that is was very efficient to it's tuned frequency. That said, I am having a heck of a time finding data on that... 
So I suspect you are onto something.
2 interesting finds googling around. 1st was a trap built like a TL/TH... and second was VPR plates. Acronym is something in german but it is basically a large dampened piece of steel plate that has been proven to reduce LF energy.
So I suspect you are onto something. 2 interesting finds googling around. 1st was a trap built like a TL/TH... and second was VPR plates. Acronym is something in german but it is basically a large dampened piece of steel plate that has been proven to reduce LF energy.
Based on listening, ASC type tube traps make things sound worse below 100hz or so.
Damped 1/4W traps tuned to the floor-to-ceiling resonance sound better than an EQ based solution.
Tuned diaphragms work well too. A loudspeaker in a sealed box with its resonance at the desired frequency can have its damping altered with an adjustable resistor across the voice-coil.
Active cancellation also works.
US Patent 4899387: Active low-frequency acoustic resonance suppressor
Read more at https://www.stereophile.com/interviews/nelson_pass_patents/index.html#UEEuzYfI8FeD5Hdh.99
Damped 1/4W traps tuned to the floor-to-ceiling resonance sound better than an EQ based solution.
Tuned diaphragms work well too. A loudspeaker in a sealed box with its resonance at the desired frequency can have its damping altered with an adjustable resistor across the voice-coil.
Active cancellation also works.
US Patent 4899387: Active low-frequency acoustic resonance suppressor
Read more at https://www.stereophile.com/interviews/nelson_pass_patents/index.html#UEEuzYfI8FeD5Hdh.99
Hi all,
In reference rooms you usually find a mixture of panel and membrane absorbers but I never came across tube traps. Perhaps it is because tubes have a 1/4WL and 3/4WL as result of length and diameter of the tube. Therefore you can only tune one of them on the desired frequency while the other probably falls in the wrong place. I suppose tube traps have stiff walls and therefore a relative high Q. Increasing the density of internal absorption material can lower that , but looking at the amount of absorption material needed, I would call it 'used effectively'.
In Tom Hidley's solution the 1/4WL is determined by the size and mass of the panels while the 3/4WL absorption is determined/tuned by the distance between the panels (volume control). In other words, you both can locate them where you need them. The 'free hanging' 1/4WL panels have all together an incredible absorption surface, far larger than any of the other options mentioned. Panels have a relative high Q if you don't damp them with deadsheet (or poormans deadsheet: bitumen or liquid rubber). The panels can become wide band absorbers at the same time by gluing/nailing absorption material on top of each side.
@Sam, I can only recommend reading as much you can from people like Tom Hidley (Westklake and Eastlake), John Storyk (Walter-Storyk Design Group), Philips Newell, Andy Munro (Andy Munro Acoustics) and pro's like that. There are also AES papers and academic studies on the subject and I suppose (at least some of them) can be found on the net. My advise, take your time before going drastic ;-)
Regards,
Djim
In reference rooms you usually find a mixture of panel and membrane absorbers but I never came across tube traps. Perhaps it is because tubes have a 1/4WL and 3/4WL as result of length and diameter of the tube. Therefore you can only tune one of them on the desired frequency while the other probably falls in the wrong place. I suppose tube traps have stiff walls and therefore a relative high Q. Increasing the density of internal absorption material can lower that , but looking at the amount of absorption material needed, I would call it 'used effectively'.
In Tom Hidley's solution the 1/4WL is determined by the size and mass of the panels while the 3/4WL absorption is determined/tuned by the distance between the panels (volume control). In other words, you both can locate them where you need them. The 'free hanging' 1/4WL panels have all together an incredible absorption surface, far larger than any of the other options mentioned. Panels have a relative high Q if you don't damp them with deadsheet (or poormans deadsheet: bitumen or liquid rubber). The panels can become wide band absorbers at the same time by gluing/nailing absorption material on top of each side.
@Sam, I can only recommend reading as much you can from people like Tom Hidley (Westklake and Eastlake), John Storyk (Walter-Storyk Design Group), Philips Newell, Andy Munro (Andy Munro Acoustics) and pro's like that. There are also AES papers and academic studies on the subject and I suppose (at least some of them) can be found on the net. My advise, take your time before going drastic ;-)
Regards,
Djim
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I think the punchy bass he refers to is around 60 - 70Hz. As he mentioned "chest thumping" in his post. And yes the room might be causing the unwanted resonance. Take the speakers outside and play a song that you know has the punchy bass you desire and tune the system there. Maybe just tweaking the EQ knobs on the mixer can help you out.
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I personally feel that punchy/chest thumping (kick drum) is strong midbass around 100-300hz maybe even higher. In that past I made the mistake of tuning my system too scooped there and things got flabby. Nowadays a strong mid bass is my secret sauce so to speak. I am a rock guy and I try and get both the kick drum and snare to pop nicely though here. I would suggest XO sub a bit higher and see of that helps.
Thanks on the trap info guys. I would actually love to create a thread about my space, talk more, and get your insights but unsure where to go... Construction tips? Or maybe just continue OT here since the OP is long gone...
Thanks on the trap info guys. I would actually love to create a thread about my space, talk more, and get your insights but unsure where to go... Construction tips? Or maybe just continue OT here since the OP is long gone...
This is a chest thumping kick drum. Sounds to me like 60 - 70 Hz.
It comes in at 30 seconds in.
https://www.youtube.com/watch?v=ypXcPRUQMUE
It comes in at 30 seconds in.
https://www.youtube.com/watch?v=ypXcPRUQMUE
https://www.youtube.com/watch?v=hjSpDB1Fc6A
When the snare comes in (around 1:00), it should take the top of your head off!
The mids from about 150hz to about 3.2Khz have to be right in order for the bass to have that 'punch' and 'slam'.
When the snare comes in (around 1:00), it should take the top of your head off!
The mids from about 150hz to about 3.2Khz have to be right in order for the bass to have that 'punch' and 'slam'.
Hi Guys, Thanks for your feedback. I Have now invested in Two DSP regulated Amps which gives me parametric EQ which is really useful and can be programmed by software. I Have eliminated most Phase difference by calculating the distance. and getting constructive interference. ( Wavelength = (slit distance X Distance from gaps.) all divided by the depth. so that has been eliminated ( Thanks A-level Physics) but as for the actual EQ I am struggling which is better. 200Hz or 80 Or dead in the middle of Both! Thanks
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