Thanks for all the responses on my question of 'smear'. More than I expected. Grateful.
Hope it's OK for follow-up questions.
1. I know it is subjective but what kind of impact does the 'smear' have - especially in precise focused imaging? Part of the allure of full range is the coherence and wondering how this impacts that sense.
2. And given that this is ideally corner loaded and thus, closer to the walls, how does it impact the perception of depth (front/back)? I recently tested a pair of speakers designed to abut right at the back wall. The designer claimed in some extensive personal dialogue that it is designed so that there will be a good communication of depth, in addition to width and height. Well, it did not have much depth at all. Scale left/right yes, but no depth. I found that in my room, speakers need to be at least 3 feet away from the wall (the front driver) to give that sense of depth. The back of the FHs (MK3 and XL) are much closer to the wall though the driver is further away - hence my question.
Thanks!
UL
ps: Chrisb, do wish that there are some graphs of frequency response of the Mk3 vs XL....
Hope it's OK for follow-up questions.
1. I know it is subjective but what kind of impact does the 'smear' have - especially in precise focused imaging? Part of the allure of full range is the coherence and wondering how this impacts that sense.
2. And given that this is ideally corner loaded and thus, closer to the walls, how does it impact the perception of depth (front/back)? I recently tested a pair of speakers designed to abut right at the back wall. The designer claimed in some extensive personal dialogue that it is designed so that there will be a good communication of depth, in addition to width and height. Well, it did not have much depth at all. Scale left/right yes, but no depth. I found that in my room, speakers need to be at least 3 feet away from the wall (the front driver) to give that sense of depth. The back of the FHs (MK3 and XL) are much closer to the wall though the driver is further away - hence my question.
Thanks!
UL
ps: Chrisb, do wish that there are some graphs of frequency response of the Mk3 vs XL....
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It is believed that as low in frequency as this occurs at the ear/brain is less sensitive to it.
Ideally cornerloaded with FE126 or similar. Less so with other drivers. I have FHXL in play right now. The horns are pushed right back against a set of (FH3) deflectors which puts the driver 7/10m out from the wall.
FH3 or FHXL are much more 3D imagewize with EnABLed drivers (what i listen for to quickly pick EnABLed drivers in a blind test).
I alsolost some of the 3Dness when i substituted my backup DAC for my good one which seems to have failed
ps: Chrisb, do wish that there are some graphs of frequency response of the Mk3 vs XL....
Scott may have some sims (for that matter i might as well), but he is on the road right now. Any room measure likely tells you more about the room, and anechoic measures would not paint a realistic picture.
dave
Other off-topic moved here:http://www.diyaudio.com/forums/full-range/269393-p10-hifi-alpair-7-3en-sdx7en-fast.html
Quick question on the CNC files for the FH-XL.
If one gets the files, can it simply be uploaded for someone with a CNC machine and the CNC machine can simply start routing/cutting out the speaker panels or is there a lot of work still to program the depth of the sheets on the table etc?
Thanks!
UL
If one gets the files, can it simply be uploaded for someone with a CNC machine and the CNC machine can simply start routing/cutting out the speaker panels or is there a lot of work still to program the depth of the sheets on the table etc?
Thanks!
UL
For example, in the production environment in which the FH CNC machined kits are fabricated, the original CAD files may originate as DXF from either Dave's Vectorworks, or my 20 yr old version of AutoSketch, are imported into AutoCAD for verification, saved as DWG, exported to the CAD/CAM suite module Aspan for final conversion to G- code to the Morbidelli Author 600 series point to point router.
In our case, a single CAD drawing can result in optimized cut-plan programs to CNC panel saw, edgebander, and the P-t-P router, as well as bills of materials for all sheet goods, solid wood, specified hardware - drawer slides, hinges, cabinet pulls, etc
Of course every CNC environment is different as to complexity, the ease of programming directly at the machine console, or number of steps required from drawing to pushing of the "run" button.
In our case, a single CAD drawing can result in optimized cut-plan programs to CNC panel saw, edgebander, and the P-t-P router, as well as bills of materials for all sheet goods, solid wood, specified hardware - drawer slides, hinges, cabinet pulls, etc
Of course every CNC environment is different as to complexity, the ease of programming directly at the machine console, or number of steps required from drawing to pushing of the "run" button.
From my experience with fh3 plans (should be similar in terms of work) it takea a qualified cnc technician anywhere between 5 and 30 minutes depending on how much of the work you can prepare upstream.
For example, I submit a DWG file with the tool offset routing already included in the drawing.
For cutting it takes roughly 3-5 minutes/panel
hope it helps
For example, I submit a DWG file with the tool offset routing already included in the drawing.
For cutting it takes roughly 3-5 minutes/panel
hope it helps
DXF's are better than word documents as they are dimensionally accurate (ever tried printing out a exact shape on a printer?)
I got our guy to redraw the files in SolidWorks, as I wanted rebates on all panels and fancy driver cut-outs.
CNC kits
The output files could be read by any CNC machine.
All they have to do is tell it which side of the line to cut, and the depth of the material/rebate. Any good software works out all the technical tooling bits.
Most cnc/shops will charge a standard set up fee, but all the programming should all easily be done within half hour.
Ive been asked if I would share our CNC DXF. This took our engineer a day to draw out, not sure how Dave feels about making a few quid to offset this. User would also have to pay the donation to DIY audio for the privilege.
Our plan took 20-25mins to cut on a big SCM machine. And uses 1 full 8' x 4' sheet and 1/3rd 8' x 4' sheet.
I got our guy to redraw the files in SolidWorks, as I wanted rebates on all panels and fancy driver cut-outs.
CNC kits
The output files could be read by any CNC machine.
All they have to do is tell it which side of the line to cut, and the depth of the material/rebate. Any good software works out all the technical tooling bits.
Most cnc/shops will charge a standard set up fee, but all the programming should all easily be done within half hour.
Ive been asked if I would share our CNC DXF. This took our engineer a day to draw out, not sure how Dave feels about making a few quid to offset this. User would also have to pay the donation to DIY audio for the privilege.
Our plan took 20-25mins to cut on a big SCM machine. And uses 1 full 8' x 4' sheet and 1/3rd 8' x 4' sheet.
Honestly, if considering investing in 2 Alpair drivers per enclosure, I think a better approach would be A12PW / A7.3 or even A6M combo, in MLTL, XO anywhere between 250Hz and your favorite point. Indeed, I think there was a design by Mark for something along those lines, perhaps it was a simple BR? - hard to recall exactly, but Dave or Scott would have a clue.
You wouldn't want to have them in the sameenclosure. Something like this lashup we did one diyFEST would work...
Here the FE138eSR, the limited edition driver that raises the Fostex shout to a screech, and a set of uFonkenXK active at 100 Hz 2nd order (an old Ace Audio XO that was kicking around). The FE138 in FH3 can sure kick out the bass.
dave
Attachments
Should work ok, as that particular combo is the one I'd pursue for my own use. The only issue is the A6p (and metal?) are about 1.5db down SPL wise from the 12wp. Of course, if you're bi-amping with PLL components, it's not going to be an issue. I drew up a box model after Mark introduced the A12WP. IIRC it's close to 50L in volume.
jeff
Attachments
Typically, with a passive XO at the bafflestep the woofer should be 2-6 dB more sensitive.
dave
Alpair 10p question
I guess this is off topic, but with the mark audio forum down, I'm hoping to find help here. I just had an amp start to act up, and one speaker developed a hummm. I brought the amp up to my desk and hooked up my trash tester speaker to it to take some measurements. When I turned the amp on, the speaker began to smoke.
So, after unhooking the toast, I took some measurements. Got 16.64 v dc at the speaker output! I haven't had the heart to even test the Alpair yet. I have sniffed around it (of course it's pretty sealed in the top of its box...) to no avail. I will be hooking it up to another amp to check it out—but what are the chances that it's undamaged? I was just at the 350 hour point, too! Besides simply listening to it and it's mate, are there any specific tests I can do? Will I possibly damage it further by trying to use it?
I guess this is off topic, but with the mark audio forum down, I'm hoping to find help here. I just had an amp start to act up, and one speaker developed a hummm. I brought the amp up to my desk and hooked up my trash tester speaker to it to take some measurements. When I turned the amp on, the speaker began to smoke.
So, after unhooking the toast, I took some measurements. Got 16.64 v dc at the speaker output! I haven't had the heart to even test the Alpair yet. I have sniffed around it (of course it's pretty sealed in the top of its box...) to no avail. I will be hooking it up to another amp to check it out—but what are the chances that it's undamaged? I was just at the 350 hour point, too! Besides simply listening to it and it's mate, are there any specific tests I can do? Will I possibly damage it further by trying to use it?