@PWRRYD said:
I am really looking forward to hearing this w/wo imp comp comparison with my tube amp. I am guessing there will be an audible difference, just don't know how much there will be.__
There should be a difference, but the question is how much, subtle or OH DAMN!
I will be there sometime Friday afternoon, I'm looking forward to seeing your tube amp. I like tubes, it may be because I remember tube equipment when I was a kid, granted it was older stuff, but back then people kept things longer and they lasted longer. No built in failure date.
Ii think you guys should also test this with a class D to see if it affects the class D output filter. In theory the inductor capacitor filter should react to the change in load.
This is pretty fascinating stuff and even though most of it is like Greek to me, it will be fun to run the comparisons. In past DIY audio shows there have been numerous “tests” conducted (crossovers (cap tests), different classes of amps, passive vs active XOs, full range speaker comparisons, etc etc.). Very stoked to be part of this and glad we are all gathering to make it happen!! Oh, and I can’t wait to see/hear these old school style speakers too!!
I stopped using Class D years ago for measurements due to some errata in the higher frequencies. Probably inherent to the cheaper amp I was using (I think it was the Dayton something or other). I then used it as my desktop amp for awhile, but it suffers from turn-on thump.
Then I bought the similar sized FX-Audio, and it was an improvement.
Currently my desktop amp is the SMSL from the same power class as the Dayton and the FX_Audio. Definitely a better amp than the other two.
I still won't do measurements with any of them. I use a Dayton APA150 for that.
You guy's can bring whatever you want and test as much as you like with my speakers even if I'm not in the room, but I don't want to be the guy who is monopolizing all the time with my junk.
I didn't mean to stir the pot with the mention of the class d output filters. To be honest I feel the class d data to be more real world practical than the tube state.
If you like tube sound get a tube preamp. Pair that with a class d or ab and enjoy. No judgment just an honest recommendation.
You spent more time on, and executed the midrange sub-enclosure with more precision that some folks do on their entire speaker system. Crossovers included.
Looks pretty cool.
I was asked several times at Iowa about the sensitivity of these and I could only guess at about 87db, well I just took a quick measurement at about 2.83v and it shows about 87db, but the accuracy of this is questionable.
I also was questioned about the complexity of the crossover, and I don't see it as anything out of the ordinary except perhaps the lcr that I had to use in order to squish the upper impedance peak of the woofer's twin bass reflex peaks.
This is the revised schematic, fixing the l6 value that Craig pointed out. Thanks Craig.
I can't say whether there is a difference in how the mid measures or sounds with a normal enclosure, and by normal I assume that you mean a rectangle, because I didn't build and test any other shapes.
My philosophy on mid enclosures is that it's not much more difficult/trouble to build them with non parallel walls, so why build a rectangle. I've used 5 sided pointed enclosures like this one, truncated pyramids, and various angled walls and never been disappointed or measured any abnormalities with them. With the dimensions of a typical mid enclosure the resonances and standing waves could easily be in the mid's bandwidth, so I figure why not eliminate as much of the possibility as....possible.
Looking at rear chambers on sealed back mids and tweeters, there is a precedence for "not a rectangle" sub-enclosures. Years ago when I modified some MB Quart dome mids, I used a drinking cup and threw a golf tee in the back, why not. Got the answer looking at nice tweeters and their chamber geometry.
The finish on these is just outstanding. On par with expensive hand-made furniture. Nick, I really hope you won't have to completely rebuild the outer box. But if you do, these are surely worth the effort. They sounded amazing and I thought your voicing was perfect!
Comments
Tom check out my thread "My solution to parts storage".
There should be a difference, but the question is how much, subtle or OH DAMN!
I will be there sometime Friday afternoon, I'm looking forward to seeing your tube amp. I like tubes, it may be because I remember tube equipment when I was a kid, granted it was older stuff, but back then people kept things longer and they lasted longer. No built in failure date.
Ii think you guys should also test this with a class D to see if it affects the class D output filter. In theory the inductor capacitor filter should react to the change in load.
Depends if the negative feedback loop is before or after the filter and what the corner frequency is.
This is pretty fascinating stuff and even though most of it is like Greek to me, it will be fun to run the comparisons. In past DIY audio shows there have been numerous “tests” conducted (crossovers (cap tests), different classes of amps, passive vs active XOs, full range speaker comparisons, etc etc.). Very stoked to be part of this and glad we are all gathering to make it happen!! Oh, and I can’t wait to see/hear these old school style speakers too!!
I stopped using Class D years ago for measurements due to some errata in the higher frequencies. Probably inherent to the cheaper amp I was using (I think it was the Dayton something or other). I then used it as my desktop amp for awhile, but it suffers from turn-on thump.
Then I bought the similar sized FX-Audio, and it was an improvement.
Currently my desktop amp is the SMSL from the same power class as the Dayton and the FX_Audio. Definitely a better amp than the other two.
I still won't do measurements with any of them. I use a Dayton APA150 for that.
Looking forward to the weekend!
Should I lug my ClassDaudio amp along too?
ClassDaudio amp loaded...
I have an old Gainclone I designed years ago that I'll throw in the car too.
You guy's can bring whatever you want and test as much as you like with my speakers even if I'm not in the room, but I don't want to be the guy who is monopolizing all the time with my junk.
This sounds like an awesome Friday evening experiment for anyone interested
Absolutely, don't want to see any magic smoke, just want to hear if there are any differences in amps and impedance compensation.
Just omit Barbie Girl from the list of eligible tracks for this experiment and all should be good. Barbie Girl requires a minimum 100db SPL.
I didn't mean to stir the pot with the mention of the class d output filters. To be honest I feel the class d data to be more real world practical than the tube state.
If you like tube sound get a tube preamp. Pair that with a class d or ab and enjoy. No judgment just an honest recommendation.
You spent more time on, and executed the midrange sub-enclosure with more precision that some folks do on their entire speaker system. Crossovers included.
Looks pretty cool.
TomZ
**ZARBO AUDIO ** https://www.youtube.com/channel/UCEZUyvobRaFQSTl6NdOwgxQ
Thanks Tom, I always try to do at least decent work, I just can't "not care" about the results, it's just not me.
I was asked several times at Iowa about the sensitivity of these and I could only guess at about 87db, well I just took a quick measurement at about 2.83v and it shows about 87db, but the accuracy of this is questionable.
I also was questioned about the complexity of the crossover, and I don't see it as anything out of the ordinary except perhaps the lcr that I had to use in order to squish the upper impedance peak of the woofer's twin bass reflex peaks.
This is the revised schematic, fixing the l6 value that Craig pointed out. Thanks Craig.
Where is the midrange enclosure detailed? I tried looking on Diyaudio, and could not find the project.
Is L6 really 1 mH?
Nope, it should be .4mh, sorry my fault.
I really didn't detail it, but there are photos on pages 2 & 3.
Oh ok. Yeah, I can see how that would help. Can you hear or measure any difference from a "regular" midrange enclosure?
I can't say whether there is a difference in how the mid measures or sounds with a normal enclosure, and by normal I assume that you mean a rectangle, because I didn't build and test any other shapes.
My philosophy on mid enclosures is that it's not much more difficult/trouble to build them with non parallel walls, so why build a rectangle. I've used 5 sided pointed enclosures like this one, truncated pyramids, and various angled walls and never been disappointed or measured any abnormalities with them. With the dimensions of a typical mid enclosure the resonances and standing waves could easily be in the mid's bandwidth, so I figure why not eliminate as much of the possibility as....possible.
Looking at rear chambers on sealed back mids and tweeters, there is a precedence for "not a rectangle" sub-enclosures. Years ago when I modified some MB Quart dome mids, I used a drinking cup and threw a golf tee in the back, why not. Got the answer looking at nice tweeters and their chamber geometry.
For those of you who weren't at Iowa, I took a header while carrying one speaker on Saturday afternoon. Here's the carnage.
There was a collective groan as this happened. These were my favorite aesthetic this weekend.
I hear it wasn't just the speaker.... ;-(
Glad you're okay, Nick!
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The finish on these is just outstanding. On par with expensive hand-made furniture. Nick, I really hope you won't have to completely rebuild the outer box. But if you do, these are surely worth the effort. They sounded amazing and I thought your voicing was perfect!
Thanks Ben, the lip is healing, and I have a dentist appointment for next Tuesday, so I'm almost fine.