Holy Voice coils, Batman! The tweeter went Pop!
Just got my new crossovers built and installed - now with twice the elements (4!) and they sound and measure really nice. That is, until I ran a swept sine with a 700W amp on speakers rated at 30W. ooops..... There goes a voice coil.
Time for a Parts Express order.
Just got my new crossovers built and installed - now with twice the elements (4!) and they sound and measure really nice. That is, until I ran a swept sine with a 700W amp on speakers rated at 30W. ooops..... There goes a voice coil.
Time for a Parts Express order.
https://www.youtube.com/watch?v=JNS42Na2mpc
"Cave men, cave women....Troglodytes" Jimmie Castor Bunch
https://www.youtube.com/watch?v=VlRXQEA0yj0
Russellc
"Cave men, cave women....Troglodytes" Jimmie Castor Bunch
https://www.youtube.com/watch?v=VlRXQEA0yj0
Russellc
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I'm answering some questions that were asked in another thread. You can get to the original question my clicking on the blue > icon in the quote.
When I listen to a recording with great depth, it's astounding, I've never heard playback like it before. The other day I dug up a recording of Gregorian chant that was just crazy deep sounding. The chant filled the entire chamber behind the speakers, front to back, side to side. It sounded like a big stone church or a lava cave ought to sound.
It's easy to think that the cave is adding this reverb and depth, but that does not seem to be the case. On recordings with not much depth, the sound goes back maybe 3 or 4 feet behind the speaker, sometimes staying right at the speaker plane. This is true of stereo or mono recordings. The sound never comes out in front of the speakers or past the sides. Just deep. Some recordings are a mixer of flat and deep.
Depth was the one illusion I had a hard time getting in other systems I've owned or heard. Other people heard it, I never did - and it bothered me.
Now in this crazy cave there is all the depth one could want - IF it's in the recording. But the overall sound is flat and dry, a bit like open back headphones. It is not the acoustic I would have guessed for the space.
There are some surprises left in audio.
What I meant was that in a very dry acoustic (RT60 of <130ms evenly across the audio band) there is not a spacious sound. But there is plenty of depth, if it's in the recording. Not something I've experienced before.
The wall behind the speakers is approximately 35' (10m) distant. It's hard to photograph, but I'll give it another try. It's all basalt lava stone and very irregular. It reflects, but in a highly chaotic manner. I've looked for the reflection signature in my measurements, but have not yet found it. If it's there (it should be) it's chaotic.
When I listen to a recording with great depth, it's astounding, I've never heard playback like it before. The other day I dug up a recording of Gregorian chant that was just crazy deep sounding. The chant filled the entire chamber behind the speakers, front to back, side to side. It sounded like a big stone church or a lava cave ought to sound.
It's easy to think that the cave is adding this reverb and depth, but that does not seem to be the case. On recordings with not much depth, the sound goes back maybe 3 or 4 feet behind the speaker, sometimes staying right at the speaker plane. This is true of stereo or mono recordings. The sound never comes out in front of the speakers or past the sides. Just deep. Some recordings are a mixer of flat and deep.
Depth was the one illusion I had a hard time getting in other systems I've owned or heard. Other people heard it, I never did - and it bothered me.
Now in this crazy cave there is all the depth one could want - IF it's in the recording. But the overall sound is flat and dry, a bit like open back headphones. It is not the acoustic I would have guessed for the space.
There are some surprises left in audio.
I use linen drapes on the front wall, so assuming depth to be from the recording and the stereo setup.
I used to think of it as headphone effect when I first heard it. This changed as I discovered the scope of the image. On one recording the image extends back around 20 feet but this is unusual. Mostly in an arc of listening position radius, my speakers aren't far from the wall and centre-stage is near behind the front wall.
There are some surprises left in audio.
LOL, I was thinking he same thing. Only other thing I can think of that might be worth exploring is that a recession in the mids can create a perception of depth. Proposal: take an impulse response and window it at ~ 15 ms. If you see a broad midrange depression, that miiiight help explain it?
Shape looks about the same, but it is down almost 20 dB after the main pulse this time.
It is a very gradual decline after that, so it does look like ambechoic with the only difference being the level. True ambechoic would ideally be down 30-35 dB. The most striking thing is there is no flat ridge after the pulse, Only a steady decline.
At the listening spot, do you have recordings where the phantom voices project out to in front of the plane between the speakers? As you have no clear first reflections, just diffused patterns in theory it would be hard to know/determine where the speakers are located with music playing. So I believe the depth you perceive, if it's in the recording.
Basically you'd hear the room in the recording more than the cave you're in.
If you have plenty of room behind the listening position you could try a Haas Kicker to add spaciousness. Depending on how much room there is it would take a few panels of ply or something similar to test. If it works you could make that reflection more diffused.
You'd want that reflection somewhere between 15 and 30 ms to hit you from the back/sides at about 120 to 130 degree if zero degree is straight forward from the listening position.
Nice cave you have there! I'm officially jealous!
I'll borrow a picture from Jim1961's room to show how you can add that haas kicker:
See how the energy from the speaker gets reflected from the panel behind the LP to the side panels and reflected back to the LP?
This passive Haas Kicker will add spaciousness, the feeling of being in a large room. Some sensation of envelopment if you will. I do it with speakers at the back which indirectly reflect back to my listening position. Delayed and band passed I feed them with mostly L-R with a bit of center. The band passed part helps as a big room wouldn't have a lot of high frequency content in a reflection.
It is a very gradual decline after that, so it does look like ambechoic with the only difference being the level. True ambechoic would ideally be down 30-35 dB. The most striking thing is there is no flat ridge after the pulse, Only a steady decline.
At the listening spot, do you have recordings where the phantom voices project out to in front of the plane between the speakers? As you have no clear first reflections, just diffused patterns in theory it would be hard to know/determine where the speakers are located with music playing. So I believe the depth you perceive, if it's in the recording.
Basically you'd hear the room in the recording more than the cave you're in.
If you have plenty of room behind the listening position you could try a Haas Kicker to add spaciousness. Depending on how much room there is it would take a few panels of ply or something similar to test. If it works you could make that reflection more diffused.
You'd want that reflection somewhere between 15 and 30 ms to hit you from the back/sides at about 120 to 130 degree if zero degree is straight forward from the listening position.
Nice cave you have there! I'm officially jealous!
I'll borrow a picture from Jim1961's room to show how you can add that haas kicker:
See how the energy from the speaker gets reflected from the panel behind the LP to the side panels and reflected back to the LP?
This passive Haas Kicker will add spaciousness, the feeling of being in a large room. Some sensation of envelopment if you will. I do it with speakers at the back which indirectly reflect back to my listening position. Delayed and band passed I feed them with mostly L-R with a bit of center. The band passed part helps as a big room wouldn't have a lot of high frequency content in a reflection.
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Thanks for the info!
It is a dark, dirty, damp hole in the ground, but it has great acoustics. It was darker and drier when I first moved in, but recent rains and the irrigation of the new grass above have made it much wetter. I've been adding lights to it bit by bit. And it is soooo quiet down there. I love the pure silence.
OK. What does that mean?
No, never. Always at or behind the speakers.
The speakers don't call attention to themselves, it's true.
That is what I am coming to understand, the more recordings I listen to.
Might be impractical, but I'll try if I can.
When I first got set up in the cave, that idea jumped right out. The cave needs surround or ambient speakers. L-R would probably do for the stereo recordings.
Hey thanks.
It is a dark, dirty, damp hole in the ground, but it has great acoustics. It was darker and drier when I first moved in, but recent rains and the irrigation of the new grass above have made it much wetter. I've been adding lights to it bit by bit. And it is soooo quiet down there. I love the pure silence.
If experimenting with back/side channels, band pass them from ~200 HZ to ~4000 Hz, 12 dB/oct and delay them to about 20 ms behind the main peak.
Attenuate them so you just can't hear them at the listening position. Maybe a bit further down. Don't let it come from straight behind but a bit more from the sides.
A diffused and de-correlated signal works best. I have the speakers point outwards and reflect it of whatever is in their path. One side it's a wall and some loose accessories on a side table, the other side is a desk. Reflected will work better than a speaker directly pointed at the listening position.
The FR is shaped roughly to follow the FR of main speakers. Bigger speakers could perhaps dive below 200 with good results, I use Scan Speak 10F in a small sealed enclosure and haven't tried them lower yet.
While I have (L-R) and (R-L) as the base signal, I did mix a bit of centre in about 7 dB lower and with a slightly different delay.
Hope it works for you, the speaker option is easier to get right I suppose as you can play with level and substance. I did the mixing for the channels in JRiver.
See: http://www.linkwitzlab.com/surround_system.htm for a very similar solution.
About that flat ridge, here's my ETC:
As you see it does have reflections, but luckily they are down (absorption) but yours lacks definitive reflections and is way more diffuse starting immediately with the decline.
Here's my ETC with the Haas kicker active or in other terms the termination of the reflection free zone:
The peak here is without 4 kHz lowpass, the final level of the termination was about -15 dB.
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More Photos
Here are some photos I took tonight. The cave is hard to photograph, but I'm learning how.
You can see a wide panoramic mode, then a photo of the puka (hole) where the speakers reside, behind that hole with the colored lights is the rear chamber. The rear chamber looks flat in the photo, but it's actually sort of oval shaped, about 35 feet (10m) to the back wall. You might see the shadow of the chair at the LP. It's 26' back from the speakers with another 20 feet of space behind that.
What you should be able to see well is how rugged and uneven it all is. Reflections die very quickly in there. It's possible that some of the lava rock in absorptive, but mostly is the jumbled, chaotic nature of the space that gives it the interesting hypo-echoic acoustics.
Here are some photos I took tonight. The cave is hard to photograph, but I'm learning how.
You can see a wide panoramic mode, then a photo of the puka (hole) where the speakers reside, behind that hole with the colored lights is the rear chamber. The rear chamber looks flat in the photo, but it's actually sort of oval shaped, about 35 feet (10m) to the back wall. You might see the shadow of the chair at the LP. It's 26' back from the speakers with another 20 feet of space behind that.
What you should be able to see well is how rugged and uneven it all is. Reflections die very quickly in there. It's possible that some of the lava rock in absorptive, but mostly is the jumbled, chaotic nature of the space that gives it the interesting hypo-echoic acoustics.
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