Spedge,
Ahhh, That's better! I shoulda known. I'm too rusty. 5.1 ohms. Big difference! Thanks. You would not believe that I actually have a degree in computer electronics. It's from 1976, so it has been a while. I have probably burnt through at least a whole roll of solder, a 1/16" at a time. I used to rebuild computer tape drives and 11x11 stage stepping switches, and even used to rebuild the focusing end of a giant CRT, and made the filaments for them (liquid nitrogen and a huge vacuum pump for drawing back down the vacuum). It was for an old radar system over-looking the East German border. You couldn't get parts, so I was the guy that rebuilt or made them. I was the electro-mechanics guy in an electronics depot. They sent the basket cases to me, and if I couldn't fix it or make it, they threw it away.
The way my system is set up is this: I have (2) sets of 4 ohm box speakers wired in series, so 8 ohms each channel. The sensitivity is probably 86 or so db. They seem to be about the same loudness as the DMLs. I want to play all (3) sets together. I have several 4 ohm resistors and 1 ohm resistors, so I can tweak the boxes or DMLs to balance the output. The boxes will be in the corners of the room, and the DMLs will be in the middle against one side, in front of where I sit. The room is about 10.5x 12.5'. Should I wire them as series to get 13 ohms, or parallel with a 4 ohm resistor added to the DMLs to end up with 4 ohms? I don't want to go any lower than 4 ohms load to the amp. I can add 1 ohm resistors to the arm that's too loud.
Ahhh, That's better! I shoulda known. I'm too rusty. 5.1 ohms. Big difference! Thanks. You would not believe that I actually have a degree in computer electronics. It's from 1976, so it has been a while. I have probably burnt through at least a whole roll of solder, a 1/16" at a time. I used to rebuild computer tape drives and 11x11 stage stepping switches, and even used to rebuild the focusing end of a giant CRT, and made the filaments for them (liquid nitrogen and a huge vacuum pump for drawing back down the vacuum). It was for an old radar system over-looking the East German border. You couldn't get parts, so I was the guy that rebuilt or made them. I was the electro-mechanics guy in an electronics depot. They sent the basket cases to me, and if I couldn't fix it or make it, they threw it away.
The way my system is set up is this: I have (2) sets of 4 ohm box speakers wired in series, so 8 ohms each channel. The sensitivity is probably 86 or so db. They seem to be about the same loudness as the DMLs. I want to play all (3) sets together. I have several 4 ohm resistors and 1 ohm resistors, so I can tweak the boxes or DMLs to balance the output. The boxes will be in the corners of the room, and the DMLs will be in the middle against one side, in front of where I sit. The room is about 10.5x 12.5'. Should I wire them as series to get 13 ohms, or parallel with a 4 ohm resistor added to the DMLs to end up with 4 ohms? I don't want to go any lower than 4 ohms load to the amp. I can add 1 ohm resistors to the arm that's too loud.
Same problem with my iPhone. Try this trick - it’s the only way I can post pix from my phone. Take a screenshot of your photo. It’s about the right resolution for uploading to DIYA. Works like a charm and lets you crop all in one.
It’s pretty lame when one has to take a screenshot to alter the resolution. Otherwise email to yourself and you can select the resolution. But faster to screenshot it.
This is all great stuff you and the others are leading in this thread. I am really far behind. Good to know about noise from transducers squeezing air through holes etc. anything near a tweeter will cause dips. Unless it’s a well designed wave guide.
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Just tested it.
Works fine for me.
You can choose the size at the bottom of the photo selection screen (“actual size, large, medium or small” I believe they are called in English).
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Xrk971.
Thanks .
A dumb question ,but how do I take a screen shot of my photo ?
I've been taking pictures of the different responses of different domes and materials and making some recordings,for my own references.
The recordings are very helpful for quick comparisons, but I must admit the pictures are pretty bad and seem to be getting worse?
Steve.
Thanks .
A dumb question ,but how do I take a screen shot of my photo ?
I've been taking pictures of the different responses of different domes and materials and making some recordings,for my own references.
The recordings are very helpful for quick comparisons, but I must admit the pictures are pretty bad and seem to be getting worse?
Steve.
Spedge,
I have been using "faststone capture 5.3" for years to capture parts of a screen. Go to Faststone Capture 5.3 and select "(old version)", and download. It's the version that's still free. I attach it to my taskbar. You can play with the color balance, hue, brightness, sharpness, etc, and can rotate and crop. I love it. It downloads your file as .jpg or .png, your choice.
I have been using "faststone capture 5.3" for years to capture parts of a screen. Go to Faststone Capture 5.3 and select "(old version)", and download. It's the version that's still free. I attach it to my taskbar. You can play with the color balance, hue, brightness, sharpness, etc, and can rotate and crop. I love it. It downloads your file as .jpg or .png, your choice.
On a newer iphone, push power and up volume simultaneously to screen shot anything on your phone. On older ones, push the home button and power at the same time. I can’t say for Android but I’m sure there is a way.
Your phone can “video screenshot” too. That is, record any video you see on your screen. You can google it to find out specifics for any particular model phone.
If you have an XLR mic and an XLR mic to USB Interface (like Focusrite, Behringer, M-audio, etc.), you are golden. Just download REW and play with it. It will change your life!
If you recall from Post 1 of this thread, it’s nice to get a frequency response with harmonic distortion components in same graph:
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Xrk971.
Sorted !!
I do have REW on my computer ,it's been there for some years now ,it's just that I'm so tight ,I don't want to spend the money on something that I'll only probably use to post on line .
I do agree REW is a fantastic piece of kit and maybe one day I'll give it a go,but I certainly don't need it to tell me if a panel sounds good or not.
I was going to put my LP collection on to my computer,and I did put quite a few on,but have decided to put them on CD now, as every time I turn the computer on I waste hours of my life sorting out problems and updates .
So the less I have to do with computers the better
I think I'm starting to get computer phobia .
But at least now I've got decent photos
Steve.
Sorted !!
I do have REW on my computer ,it's been there for some years now ,it's just that I'm so tight ,I don't want to spend the money on something that I'll only probably use to post on line .
I do agree REW is a fantastic piece of kit and maybe one day I'll give it a go,but I certainly don't need it to tell me if a panel sounds good or not.
I was going to put my LP collection on to my computer,and I did put quite a few on,but have decided to put them on CD now, as every time I turn the computer on I waste hours of my life sorting out problems and updates .
So the less I have to do with computers the better
I think I'm starting to get computer phobia .
But at least now I've got decent photos
Steve.
Spedge,
I spend untold hours uploading my cds to my computer. My laptop has a cd reader/writer, then microsoft decided that I shouldn't be using it, and changed the way it read the material. Now I have to go through their music reader, jump through the hoops of literally about 15 extra steps to finally get to the same point I used to be at when I just put a cd in and read the songs into my library. Why can't they just leave me alone to do my own thing with my own computer? I wish I had an old computer with one of the ancient softwares on it that I never update, leave it offline and just dedicate it to music.
I spend untold hours uploading my cds to my computer. My laptop has a cd reader/writer, then microsoft decided that I shouldn't be using it, and changed the way it read the material. Now I have to go through their music reader, jump through the hoops of literally about 15 extra steps to finally get to the same point I used to be at when I just put a cd in and read the songs into my library. Why can't they just leave me alone to do my own thing with my own computer? I wish I had an old computer with one of the ancient softwares on it that I never update, leave it offline and just dedicate it to music.
Xrk971.
Just to show off my new sharp pictures
I was just playing around with different ideas on an old 14x24inch 1/2inch low density EPS.
Basically I'd cut out a hole in the centre and was using different materials to see what happened?
As you can see in the first picture I managed to create a midrange hump, and reduced the hf response, but not only reduced the hf response but extended it up to about 20k.
Should have taken a picture before doing to the damage to the panel
In the second picture I added this EQ to reduce the midrange hump in the first picture shown as the lower portion of that graph.
The third picture shows the in room response about 11ft into the room.
Actually they are all at 11ft into the room.
From about 250hz up, apart from a dip at about 7 k ,the response is pretty much within + and- 2.5 db.
On my daq that is ,of cause,but it is still pretty good I think?
Below about 250hz the room starts mucking up the response, that's why I use low frequency drivers to help cover this area.
This took about five minutes to set up,and a hell of a lot longer to post
I could easily do it this way ,but prefer to design it right in the first place .
That's just me
Steve.
Just to show off my new sharp pictures
I was just playing around with different ideas on an old 14x24inch 1/2inch low density EPS.
Basically I'd cut out a hole in the centre and was using different materials to see what happened?
As you can see in the first picture I managed to create a midrange hump, and reduced the hf response, but not only reduced the hf response but extended it up to about 20k.
Should have taken a picture before doing to the damage to the panel
In the second picture I added this EQ to reduce the midrange hump in the first picture shown as the lower portion of that graph.
The third picture shows the in room response about 11ft into the room.
Actually they are all at 11ft into the room.
From about 250hz up, apart from a dip at about 7 k ,the response is pretty much within + and- 2.5 db.
On my daq that is ,of cause,but it is still pretty good I think?
Below about 250hz the room starts mucking up the response, that's why I use low frequency drivers to help cover this area.
This took about five minutes to set up,and a hell of a lot longer to post
I could easily do it this way ,but prefer to design it right in the first place .
That's just me
Steve.
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Xrk971.
This was the in room response of one of my big EPS panels without EQ,even better.
This I took many years ago now.
this is the same panel at 12FT into room ,showing dip between 80 and 300 HZ
This is with the low frequency driver .
this is with the TLs turned on ,with no eq,at 12FT into room so can be improved, notice the ledge at 10K with this panel but the panel radiates this hf in all directions, could eq this but sounds natural to me ?
There are ways to improve the top end but that's a different story
Steve.
This was the in room response of one of my big EPS panels without EQ,even better.
This I took many years ago now.
this is the same panel at 12FT into room ,showing dip between 80 and 300 HZ
This is with the low frequency driver .
this is with the TLs turned on ,with no eq,at 12FT into room so can be improved, notice the ledge at 10K with this panel but the panel radiates this hf in all directions, could eq this but sounds natural to me ?
There are ways to improve the top end but that's a different story
Steve.
I should show this picture as well to show the response at 1ft
Steve.
this is a bog standard 25mm panel 5x2FT at a distance of 1ft
Steve.
this is a bog standard 25mm panel 5x2FT at a distance of 1ft
Xrk971.
I have three panels drying at the moment.
This one is wood ply that peeled off from a 1940s draw in my shed.
I coated the ply in 50x50 pva.
It is 1mm thick and 9x6inches ,I've just glued the exciter with dome in position ,and cut the corners to reduce vibrations.
The first picture is about 4inches in front of the exciter.
The second is 3mtrs into the room,both are rolled off at 170hz to keep LF well away.
This is how easy it is to make a pretty good sounding panel speaker,wit very little effort of course I could improve on this with a little more effort, it's still drying so the response will change a little in a few days.
I could not use the panel without the dome as there was already a hole where the draw handle was
So sorry, no comparison.
But it's all about the sound.
Although it's pretty good fun too.
I will when I get time do a recording ,hopefully with a higher quality conversion rate ,for you to make up your own mind whether it' sounds good ,or not?
Steve.
I have three panels drying at the moment.
This one is wood ply that peeled off from a 1940s draw in my shed.
I coated the ply in 50x50 pva.
It is 1mm thick and 9x6inches ,I've just glued the exciter with dome in position ,and cut the corners to reduce vibrations.
The first picture is about 4inches in front of the exciter.
The second is 3mtrs into the room,both are rolled off at 170hz to keep LF well away.
This is how easy it is to make a pretty good sounding panel speaker,wit very little effort of course I could improve on this with a little more effort, it's still drying so the response will change a little in a few days.
I could not use the panel without the dome as there was already a hole where the draw handle was
So sorry, no comparison.
But it's all about the sound.
Although it's pretty good fun too.
I will when I get time do a recording ,hopefully with a higher quality conversion rate ,for you to make up your own mind whether it' sounds good ,or not?
Steve.
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