The most important rule would be to use common sense, not the one quarter something. Then there is the evaluation which will teach you a thing or two.
Alright, ask yourself how practical is to adhere to a 1/4 wavelength x/o frequency rule. A modest 2 way loudspeaker of the usual kind, 6.5" midwoofer + 1.1" tweeter is practically crossed somewhere in the 2-2.5kHz range. One quarter of the 2kHz wavelength is about 4.3 cm. Typically, ctc distance of these units is about 15 cm. And lots of these products have been reviewed, receiving very positive feedback. This is what I meant under the first sentence of the post #21.
The second one means one is expected to do his own research, using all available and recognized modern tools designed to evaluate loudspeaker performance to come up with knowledge useful for making important design decisions.
The second one means one is expected to do his own research, using all available and recognized modern tools designed to evaluate loudspeaker performance to come up with knowledge useful for making important design decisions.
asking a question to the forum is reaserch .when I need an answer to something I type it in Google and no doubt someone somewhere has asked that question and been answered on a forum like this .
I'm keeping a record of my build purely because I enjoy looking at other people's so assume someone somewhere is the same as me .
I was asking if I had that figure correct re the 1/4 wavelength I believe it is 1/4 ideal 1/2 more realistically.
I'm very much asking questions in hope of initiating conversation about my project .
if I ask for clarification that doesn't mean I've never done any research about that subject before or don't have a clue I'm just hoping to hear from people who've done something similar and might know something I don't.
I research this sort of thing constantly and am hoping to go to work for a respected driver manufacturer in Sept.
I can't help buy feel a slight vibe of snootyness in this forum at times and don't remember it being like this previously .
perhaps others don't use the forum in the Same way as I do
I'm keeping a record of my build purely because I enjoy looking at other people's so assume someone somewhere is the same as me .
I was asking if I had that figure correct re the 1/4 wavelength I believe it is 1/4 ideal 1/2 more realistically.
I'm very much asking questions in hope of initiating conversation about my project .
if I ask for clarification that doesn't mean I've never done any research about that subject before or don't have a clue I'm just hoping to hear from people who've done something similar and might know something I don't.
I research this sort of thing constantly and am hoping to go to work for a respected driver manufacturer in Sept.
I can't help buy feel a slight vibe of snootyness in this forum at times and don't remember it being like this previously .
perhaps others don't use the forum in the Same way as I do
Would be good to measure TS of them, if possible.
Re: C2C, Vcad author kimmosto actually advocates 1.0 x 1.4
https://www.diyaudio.com/community/threads/ribbon-spacing-with-midrange.370900/page-2#post-6618385
https://www.diyaudio.com/community/...-above-10k-hz-1-4-wl-law.371070/#post-6621599
Re: C2C, Vcad author kimmosto actually advocates 1.0 x 1.4
https://www.diyaudio.com/community/threads/ribbon-spacing-with-midrange.370900/page-2#post-6618385
https://www.diyaudio.com/community/...-above-10k-hz-1-4-wl-law.371070/#post-6621599
thanks I'll read them in a bit . do i still need to measure the ts parametersif the dome comes with its own rear chamber ? I was just going to assume say 500 to 3k and see what it sounded like I don't play loud so hopefully be fine . I asked about the distances because I was thinking I might be able to squeeze another driver in between the d76 and the 24w100 and just use the 24w for the low bass
Just think any measurements would be good cause they're very old and you'd want to have a baseline for crossover development.
decided to make a small waveguide from a cheap monacor one more for looks than anything the dome came with a square front plate . made a mill out of scrap wood to see if I can do it without cracking the waveguide . my little boys going to help me do the other one later
wet sanded the underside as the plastic I'd a bit rough on the cut edge .
all in all a bit of a chore but I've done one so I might as well do the other one
still a tiny bit to co.e off and loads of mess to clear up . prob be easier with thumbnail router bit in the plywood baffle but I wanted a finished look
wet sanded the underside as the plastic I'd a bit rough on the cut edge .
all in all a bit of a chore but I've done one so I might as well do the other one
still a tiny bit to co.e off and loads of mess to clear up . prob be easier with thumbnail router bit in the plywood baffle but I wanted a finished look
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Pretty good work on the waveguides!
A neighboring musician has a pair of Dynaudio BM15s in his little studio, and I don't recall the high end being harsh in several short listens. Different setting & space, so who knows?
But I'd think a pair of those decent shape would have a ready market, no? I personally would be hesitant to sacrifice a good working pair. They're good speakers with a substantial user base. Why not make a clean fresh build from the start instead of limiting yourslef to the original 2-way & electronics? (esp the elec tronics! It's all fully integrated, and without a huge amount of detailed analysis and work, it'd be hard for most DIYers to better them with such a wholesale mod as a turning it into a 3-way, imho.
There are LOTS of good woofers & tweeters to go with your new mid-domes, and if the challenge of a passive 3-way crossover is too much (as it would be for me right now), the Hypex 3-ch plate amps would work well, tho I hear the DSP interface is a bit of a pain.
My 2 cents -- no disrespect intended.
PS -- I am impressed with the bass performance of the BM15 -- a 10" + no waveguide tweeter seems an unlikely combo, and I think there's some price paid in the mids, but overall, I found it quite a decent speaker for the purpose.
My neighbor's pair have developed a glitch that causes the tweeter to cut out sporadically. Apparently a known wear-fault caused by a failing protection relay for the driver.
A neighboring musician has a pair of Dynaudio BM15s in his little studio, and I don't recall the high end being harsh in several short listens. Different setting & space, so who knows?
But I'd think a pair of those decent shape would have a ready market, no? I personally would be hesitant to sacrifice a good working pair. They're good speakers with a substantial user base. Why not make a clean fresh build from the start instead of limiting yourslef to the original 2-way & electronics? (esp the elec tronics! It's all fully integrated, and without a huge amount of detailed analysis and work, it'd be hard for most DIYers to better them with such a wholesale mod as a turning it into a 3-way, imho.
There are LOTS of good woofers & tweeters to go with your new mid-domes, and if the challenge of a passive 3-way crossover is too much (as it would be for me right now), the Hypex 3-ch plate amps would work well, tho I hear the DSP interface is a bit of a pain.
My 2 cents -- no disrespect intended.
PS -- I am impressed with the bass performance of the BM15 -- a 10" + no waveguide tweeter seems an unlikely combo, and I think there's some price paid in the mids, but overall, I found it quite a decent speaker for the purpose.
My neighbor's pair have developed a glitch that causes the tweeter to cut out sporadically. Apparently a known wear-fault caused by a failing protection relay for the driver.
thanks yes mine had those and it cost me around £500 to have them repaired .
I had to take it to two different techs in the end they were sorted and opamps socketted for potential modding .
I couldn't figure out what bugged me so much about them they're slightly siblant at times and I hate to say it but eventually I saw a video with Danny Richie analysing they're fr I think it depends where you sit off axis to the balance you get .
he found a diffraction problem off the woofer because it wasnt recesed in the front panel as is standard for dynaudio .
I've heard them in a few diff rooms and always had a problem with the sound .
I'm going to leave the amps untouched atm I can run them active from an interface and multichannel amps for testing then make a decision what I want to do
I've got a passive pair that I love .
I'm not going to sacrifice them I'm going to take them apart build my speaker as an experiment to see if I can do it . i wont do anything i cant undo .
already got loads of ideas for new speakers to build next this is a very fund's limited build as I'm not as I'm taking a few months off to renovate a house we've bought so that rules out hypex etc atm
18sound have a couple new midrange I'd like to try with an old school sealed 12 as a 3way for my son .
he's got autism and adhd and loves everything that I love it's very touching seeing him want to be like me
defo in the future though .
thanks for commenting apriciate it 🙂
I had to take it to two different techs in the end they were sorted and opamps socketted for potential modding .
I couldn't figure out what bugged me so much about them they're slightly siblant at times and I hate to say it but eventually I saw a video with Danny Richie analysing they're fr I think it depends where you sit off axis to the balance you get .
he found a diffraction problem off the woofer because it wasnt recesed in the front panel as is standard for dynaudio .
I've heard them in a few diff rooms and always had a problem with the sound .
I'm going to leave the amps untouched atm I can run them active from an interface and multichannel amps for testing then make a decision what I want to do
I've got a passive pair that I love .
I'm not going to sacrifice them I'm going to take them apart build my speaker as an experiment to see if I can do it . i wont do anything i cant undo .
already got loads of ideas for new speakers to build next this is a very fund's limited build as I'm not as I'm taking a few months off to renovate a house we've bought so that rules out hypex etc atm
18sound have a couple new midrange I'd like to try with an old school sealed 12 as a 3way for my son .
he's got autism and adhd and loves everything that I love it's very touching seeing him want to be like me
defo in the future though .
thanks for commenting apriciate it 🙂
did a bit more today . I have to squeeze it in between waiting for coats of paint to dry in the house .
took some measurements and made a jig for cutting the cutouts .
it wasn't accurate enough to cut the holes just the right size so I'll have to have a little play with that .
I'm not sure about the layout . I want to keep the drivers as close as possible but I don't want it to look weird if I chamfer all the sides away from the drivers I don't see any reason why I can't run them up the center of the cabinet rather than off to one side .anyway ...
took some measurements and made a jig for cutting the cutouts .
it wasn't accurate enough to cut the holes just the right size so I'll have to have a little play with that .
I'm not sure about the layout . I want to keep the drivers as close as possible but I don't want it to look weird if I chamfer all the sides away from the drivers I don't see any reason why I can't run them up the center of the cabinet rather than off to one side .anyway ...
Attachments
I always wo dered what it was like under the guard and its transparent bit surprised I thought it was dust on the dome at first but it's the wadding underneath you can see through the dome
bit more progress today taking longer than I'd like but slowly getting there . glued some 15mm ply and 18mm mdf together for front baffles and finally managed to get all the holes for the drivers done . the midrange was a bit of a pain and I might do away with the little dress ring I made for it if I can think of a more elegant solution . surprising difficult to accurately rout the holes as there's a little bit of slop in the circle jig I made .might just have to put a couple extra coats of paint on as they're a hair bigger than I wanted
it looks quite smart I think but it would be nice to get the drivers closer together . just wants a little bit of tinkering as it's not quite sitting flush
