Re: Re: Re: Re: italynstylion
Dave posted it here... http://homepage.mac.com/tlinespeakers/FH/download/Lotus-CHR70-map-130409.pdf
gychang said:
Dave posted it here... http://homepage.mac.com/tlinespeakers/FH/download/Lotus-CHR70-map-130409.pdf
CHR-70 Nearfield
Got my pair of CHR-70 drivers from alpair-usa.com. 61 bucks and really nice! Thank you, Mark.
It's enclosure time. Need to do some cutting and gluing and finishing. But I can't make up my mind.
Requirements are for nearfield use at my PC workstation with a NAD 7225PE receiver as power AND in keeping with the spirit of Mark's reason for developing these drivers--low budget and simple. So a pair of CHR-70s is all that is going to be used. I need to keep the enclosures to a reasonable size since they'll be on my desk. Ah, a pair of Lotus would be great in that corner office I covet, but that is not in my reality right now.
I've modeled enclosures at 10 liters BR tuned to 51 Hz and sealed 9.5 liters. Both with appropriate damping material. I know each type of system have their advantages and disadvantages, but nearfiled is new to me. I'll probably never drive the system to high SPL since it is nearfiled.
I really don't want to build both. I know I could compromise and build the 10 liter BR enclosure to use for both and experiment (seal the ports or not, adjust the stuffing...) but I'd rather settle into a decision before that to keep this simple.
So, your opinions are welcomed on what type of enclosure would be best for nearfield use. Sealed and BR enclosures are the only types I've ever built, I've never built a system for nearfiled use--so those two facts may be a constraint as far as keeping this simple. Also, I promise I'll document the build (when I make up my mind and actually start) for anyone else looking for this kind of nearfield solution.
Got my pair of CHR-70 drivers from alpair-usa.com. 61 bucks and really nice! Thank you, Mark.
It's enclosure time. Need to do some cutting and gluing and finishing. But I can't make up my mind.
Requirements are for nearfield use at my PC workstation with a NAD 7225PE receiver as power AND in keeping with the spirit of Mark's reason for developing these drivers--low budget and simple. So a pair of CHR-70s is all that is going to be used. I need to keep the enclosures to a reasonable size since they'll be on my desk. Ah, a pair of Lotus would be great in that corner office I covet, but that is not in my reality right now.
I've modeled enclosures at 10 liters BR tuned to 51 Hz and sealed 9.5 liters. Both with appropriate damping material. I know each type of system have their advantages and disadvantages, but nearfiled is new to me. I'll probably never drive the system to high SPL since it is nearfiled.
I really don't want to build both. I know I could compromise and build the 10 liter BR enclosure to use for both and experiment (seal the ports or not, adjust the stuffing...) but I'd rather settle into a decision before that to keep this simple.
So, your opinions are welcomed on what type of enclosure would be best for nearfield use. Sealed and BR enclosures are the only types I've ever built, I've never built a system for nearfiled use--so those two facts may be a constraint as far as keeping this simple. Also, I promise I'll document the build (when I make up my mind and actually start) for anyone else looking for this kind of nearfield solution.
if you have the space for the 10 liters, buid that and stuf the port according to your taste... if a smaller would suit yr desk more, you could try the 4 liter closed with high pass cap that I built (on page 5 of this thread)
Add to post 183 (CHR-70 Nearfield)
Thanks, Henkjan. Your post reminds me that I forgot to mention that I plan to build the enclosures and then measure the system frequency response after placement at my desk. I have a dual monitor setup so the right channel speaker will be closely sandwiched in between two large flat surfaces--one straight in front of me in between the two speakers and one outside the right speaker angled toward my right ear--and I know that will have an effect on frequency response.
So, regarding appropriate filters. I'm hoping that the loudness contour on the NAD 7225PE will work as a sort of el-cheapo BSC if I need that. Regarding adding components for BSC or contour filters, I'm hoping they will not be needed, but I'm willing to go to that expense if the result is that I'll gain a significant improvement in sonic quality.
Thanks, Henkjan. Your post reminds me that I forgot to mention that I plan to build the enclosures and then measure the system frequency response after placement at my desk. I have a dual monitor setup so the right channel speaker will be closely sandwiched in between two large flat surfaces--one straight in front of me in between the two speakers and one outside the right speaker angled toward my right ear--and I know that will have an effect on frequency response.
So, regarding appropriate filters. I'm hoping that the loudness contour on the NAD 7225PE will work as a sort of el-cheapo BSC if I need that. Regarding adding components for BSC or contour filters, I'm hoping they will not be needed, but I'm willing to go to that expense if the result is that I'll gain a significant improvement in sonic quality.
If anyone is interested in EnABL'ing their CHR70, Dave and a few lucky other Canadians have begun listening to an EnABL'd pair in a sealed enclosure and their comments are posted in this thread about FR drivers for a SE amp. They're very positive about the improvement in SQ.
I think I'll start looking for a woofer to pair with my CHRs after they're EnABL'd.
I think I'll start looking for a woofer to pair with my CHRs after they're EnABL'd.
Henkjan said:
No measures yet. We always listen 1st. To be meaningful we'd need before and after. Frankly i don't need to see them.
And the measures i do, won't be as useful as the ones Mark Fenlon does after i send his set back to him.
If they can figure this out, it may help with meauring these.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=145096
dave
Just a quick update on my DCR and my listening system.
First, I finally pulled out the screwdriver and added some more acousta-stuff to the driver chamber. I added "a hand full" in each speaker with half going in the upper corner opposite the inter-chamber port and the other half in the corner opposite that. The improvement was all tonal in the bottom 3 octaves (50-400Hz). It sounds a little more balanced and less strained. I don't think it would be necessary if they were away from the wall or I was able to sit further away.
I finally got the optical digital cable for output from my computer and a PS Audio SL Three is handling the conversion duties. As much as the CD player was an improvement over my audio out from the computer, this is over the CD player. Even listening to a KEXP podcast of Steve Earle, which only 192kbps, sounded fantastic. I still find it hard to fathom that these inexpensive drivers are still not the limiting factor.
I was able to do a little A/B with my NAD C520 player with and without the PS Audio. The PS Audio adds dynamics to the upper midrange and upper midbass regions, and heft and sharpness to the bass. Alone, the NAD is a nice sounding player. The differences are not something you would have identified as missing. But with the PS Audio, it's definitely good to have.
Next on my list is EnABL'ing and doing a FAST. Right now I'm liking the CCS Trio8 and the SEAS L22, although the Dayton RSS265HF has some possibilities.
First, I finally pulled out the screwdriver and added some more acousta-stuff to the driver chamber. I added "a hand full" in each speaker with half going in the upper corner opposite the inter-chamber port and the other half in the corner opposite that. The improvement was all tonal in the bottom 3 octaves (50-400Hz). It sounds a little more balanced and less strained. I don't think it would be necessary if they were away from the wall or I was able to sit further away.
I finally got the optical digital cable for output from my computer and a PS Audio SL Three is handling the conversion duties. As much as the CD player was an improvement over my audio out from the computer, this is over the CD player. Even listening to a KEXP podcast of Steve Earle, which only 192kbps, sounded fantastic. I still find it hard to fathom that these inexpensive drivers are still not the limiting factor.
I was able to do a little A/B with my NAD C520 player with and without the PS Audio. The PS Audio adds dynamics to the upper midrange and upper midbass regions, and heft and sharpness to the bass. Alone, the NAD is a nice sounding player. The differences are not something you would have identified as missing. But with the PS Audio, it's definitely good to have.
Next on my list is EnABL'ing and doing a FAST. Right now I'm liking the CCS Trio8 and the SEAS L22, although the Dayton RSS265HF has some possibilities.
I can support that they do get loud. I have been told several times to turn it down by my wife who was down stairs. And given it's the low frequencies that transmit best through walls and floors, I can also attest to it's ~45Hz capabilities.
You're not going to chase anyone out of the room because of the volume but they will fill a 15x15 room fairly well.
You're not going to chase anyone out of the room because of the volume but they will fill a 15x15 room fairly well.
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