Hi scott, man ive taken stuffing out, replaced, moved it, used various fills.
Yes it did help, i managed to get a nice sound but still needs more work.
Ideally with no stuffing. We want all the warts. At least 1/12 octave smoothing to see detail. I'd wait a little bit before taking a saw to your TL.
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Horns are basically two octave devices, so there's a huge dip at its 3rd harmonic or one acoustic WL of the horn, making Fp around 50 Hz. The big spike is the horn, mouth driver interaction [comb filtering], but it's so high Q that folks don't normally notice them.
Of more importance is getting horn damping right to limit the horn's mid/HF output, which in turn will reduce its amplitude as a byproduct.
Your horn looks lovely, but all those wonderfully radiused bends are counterproductive, allowing way too much mids/HF to 'escape' it with increasing time delay with increasing frequency, so once damped enough to roll them off, maybe too much of the horn's [mid] bass output will be rolled off too.
GM
While I've yet to personally conduct any acoustics measurements, I've gleaned enough from both these fora and a buddy with much experience in that field. Unless all your listening will be done at the same distance as the measurements were seen in the photos to be taken, you want to eliminate as many variable/artifacts from them as possible.
In theory, you'd like to be able to completely eliminate any room effects in the measurement and design of the enclosure and XO before compensating for the particular listening environment. Of course that's way easier said than done.
The huge glitch seen centered at 200Hz that perceval attributes to phase invasion could very likely be mitigated by remeasuring at at least 1 meter, and mounting both the enclosure and mike with as few proximate reflective surfaces as possible- this could be a case of measures showing something you simply won't hear when listening to music.
I'd certainly agree with chris661's assessment of the design, and quite honestly, you could spent much time trying to make a silk purse from this, and not be much further ahead. As he'd alluded, those sexy smooth curves in the line and small irregular wavy bits at the closed end are a great excuse for a designer to use the capabilities of CNC machining, but if in aid of a flawed concept, it's a bit of a waste of the time and materials.
If you look at the various designs in Scott Lindgren's "Woden Baby Labs" series, you'll note that the acoustic centre of the driver's position is offset in relation to the end of the line - this in combination with judicious damping along the line is to control /tame the harmonics of the line's fundamental frequency. As with the placement of measuring mike, only a couple of inches can make a big difference in a line as short as 1.7 meters.
At the risk of repeating myself, the A7.3 is an excellent driver, and deserves far better than this design.
In theory, you'd like to be able to completely eliminate any room effects in the measurement and design of the enclosure and XO before compensating for the particular listening environment. Of course that's way easier said than done.
The huge glitch seen centered at 200Hz that perceval attributes to phase invasion could very likely be mitigated by remeasuring at at least 1 meter, and mounting both the enclosure and mike with as few proximate reflective surfaces as possible- this could be a case of measures showing something you simply won't hear when listening to music.
I'd certainly agree with chris661's assessment of the design, and quite honestly, you could spent much time trying to make a silk purse from this, and not be much further ahead. As he'd alluded, those sexy smooth curves in the line and small irregular wavy bits at the closed end are a great excuse for a designer to use the capabilities of CNC machining, but if in aid of a flawed concept, it's a bit of a waste of the time and materials.
If you look at the various designs in Scott Lindgren's "Woden Baby Labs" series, you'll note that the acoustic centre of the driver's position is offset in relation to the end of the line - this in combination with judicious damping along the line is to control /tame the harmonics of the line's fundamental frequency. As with the placement of measuring mike, only a couple of inches can make a big difference in a line as short as 1.7 meters.
At the risk of repeating myself, the A7.3 is an excellent driver, and deserves far better than this design.
I like your above comments Chris, just from the comments received i am learning. I agree those sexy curves is what made me want to try these out, i'm a sucker for a curve
Im going to try a build another enclosure i like the frugel horn concept as they seem to be a popular choice. My only concern is the size of them, i wanted something smaller.
Can you suggest other designs which have been tried and tested? i may take the plunge and go Frugel Horns, but interested in other designs. I have been to the mark audio website and seen what they suggest, but i want to be different and try something new!
Im going to carry on testing these enclosures i have just to practice using the software and getting used to taking measurements of the speakers and room and understanding what is going on.
Ill post more soon!
That's very encouraging. The TL port extends bass down to 50Hz. Means little or no air leaks.
Can you provide cabinet dimension? In particular the TL cross section and taper.
The combined response should look decent. You need to place the speaker on a stand at least 1m from a wall and measure 1m out at mid height (driver : port) to get the combined response. Don't measure on a table, like your picture, it adversely effects the boundary between port and table.
Your TL design will be determined primarily by the driver, offset and TL cross section and taper. More bends and damping are refinements. The cabinet is only for <300Hz, the rest of the FR matches the data sheet.
Can you provide cabinet dimension? In particular the TL cross section and taper.
The combined response should look decent. You need to place the speaker on a stand at least 1m from a wall and measure 1m out at mid height (driver : port) to get the combined response. Don't measure on a table, like your picture, it adversely effects the boundary between port and table.
Your TL design will be determined primarily by the driver, offset and TL cross section and taper. More bends and damping are refinements. The cabinet is only for <300Hz, the rest of the FR matches the data sheet.
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Well i am limited with space and where i can do my projects,you maybe right though.
I got to obviously put the speaker on a stand and the mic on a solid tripod, two extra things i need to buy
.At least it gave me a measurement to get us started.
Check these
I didn't realize these curvy things were offered as a commercial product. You can even buy a plexi glass side panel to show off the TL internals.
Shallow Bookshelf-type Back Loaded Horn Speaker Box Kits
I didn't realize these curvy things were offered as a commercial product. You can even buy a plexi glass side panel to show off the TL internals.
Shallow Bookshelf-type Back Loaded Horn Speaker Box Kits
Ok i can measure up and post it on here, as for a speaker stand, those i don't have.
I have a solid side table that they will be nicely sitting on
, saves me buying stands and hopefully will be good enough for a few measurements.
A compromise is to put the speaker at the edge of the table on a few books. Yes, that is a little risky but as long as its not tippy. The microphone can be taped to the back of a chair or a tall lamp stand. Yes, it'll look funny, oh well, send picsOk i can measure up and post it on here, as for a speaker stand, those i don't have.
I have a solid side table that they will be nicely sitting on
I like looking at the back of my VTL's with the panel off
They sound almost as good that way too
I'm still at the sandbox stage trying ideas, gluing, nail gunning, and soldering here and there. I have franken-speakers and often have to avert my eyes while listeningI like looking at the back of my VTL's with the panel off
They sound almost as good that way too
I'm still at the sandbox stage trying ideas, gluing, nail gunning, and soldering here and there. I have franken-speakers and often have to avert my eyes while listening
I tell you what ill send my speakers to you
you can sort them out for me!As lovely as those enclosures look you just never know how they will sound as i have experienced.
Unless someone has bought them, tested them and shown good results kind of like what i am trying to achieve.
You've said your speakers sounded good, this might just be an exercise in sorting out measurement and instrumentation. It looks good so far. Look at the bright side 98.5% of you FR is good and meets spec. Only 1.5% is an issue
You're correct, when it comes to buying audio gear it all comes down to how it sounds. Unfortunately once you buy it you're often stuck especially with kits.
You probably don't want to send me speakers, they might come back as http://www.diyaudio.com/forums/multi-way/303941-omnidirectional-work-progress-5.html#post5019727
You're correct, when it comes to buying audio gear it all comes down to how it sounds. Unfortunately once you buy it you're often stuck especially with kits.
You probably don't want to send me speakers, they might come back as http://www.diyaudio.com/forums/multi-way/303941-omnidirectional-work-progress-5.html#post5019727
You've said your speakers sounded good, this might just be an exercise in sorting out measurement and instrumentation. It looks good so far. Look at the bright side 98.5% of you FR is good and meets spec. Only 1.5% is an issue
You're correct, when it comes to buying audio gear it all comes down to how it sounds. Unfortunately once you buy it you're often stuck especially with kits.
You probably don't want to send me speakers, they might come back as http://www.diyaudio.com/forums/multi-way/303941-omnidirectional-work-progress-5.html#post5019727
True, a good exercise at that! I know i said they sounded good, but i'm sure there is more potential.
I mean how would they compare to a Frugal Horn, or Pensil none of which i have ever heard.
I think i might buy a pair of Frugal Horns just to test them and compare.
Anyway ill get that info to you soon, just wonder where it will lead.
Before investing any more coin on new enclosures, how about a little time and "shoe leather"? - i.e. there must be another DIYer within an easy day trip distance from you with a pair of A7s in something worth listening to.
It'll come as no surprise that I'd readily endorse the FH3 - if you have the requisite floor space -or the Pensils if more restricted. When operating full-range, I've always preferred this driver in a floorstanding enclosure - and certainly vented as opposed to sealed.
There are also a couple of small standmount/ bookshelf sized enclosures freely available here http://frugal-phile.com/boxlib/P10free/CGR-dMar-Ken73-190216.pdf , and perhaps Scott Lindgren also did a "Baby Lab" for them as well? The last is just a guess - he and Dave had been very busy, and I'd certainly not seen every single design drawing, nor even built more than a few score of them. I currently don't have access to Dave's office and computer on which such plans might reside.
It'll come as no surprise that I'd readily endorse the FH3 - if you have the requisite floor space -or the Pensils if more restricted. When operating full-range, I've always preferred this driver in a floorstanding enclosure - and certainly vented as opposed to sealed.
There are also a couple of small standmount/ bookshelf sized enclosures freely available here http://frugal-phile.com/boxlib/P10free/CGR-dMar-Ken73-190216.pdf , and perhaps Scott Lindgren also did a "Baby Lab" for them as well? The last is just a guess - he and Dave had been very busy, and I'd certainly not seen every single design drawing, nor even built more than a few score of them. I currently don't have access to Dave's office and computer on which such plans might reside.
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