hi I have a pair of above speakers I'd like to make new floorstanding cabinets for . if I increase the size of the box and keep the same size port how would this affect the tuning? would this just give me a lower f3 or would I be better keeping the internal volume the same and filling the bottom part of the box woth sand or something like that . reasons for building a floorsatng box is to make the appearance nicer for our new living room . the box would be better constructed as well with some nice veneer and some cement boards inside to hopefully get rid of any panel resonances
thansk in advance
thansk in advance
Hi jccart,
My 2 cents:
Dynaudio bm15 is designed for nearfield monitoring.
Building a bigger cabinet and using it in the living room is contra every design idea the builders had.
The results of your changes are not predictable.
Sincerely klaus
My 2 cents:
Dynaudio bm15 is designed for nearfield monitoring.
Building a bigger cabinet and using it in the living room is contra every design idea the builders had.
The results of your changes are not predictable.
Sincerely klaus
Well its a midfield monitor I wasn't going to change the width of the front panel just the height. I really like the sound of this speaker even if it is a monitor it makes a good hifi speaker
BM15 is a nice sounding speaker. I wish they had payed more attention to the crossover design. It has alot more to give sonically with a few tweaks in that area. The classic dynaudio tweeter delay circuit is not very well executed with cheap parts. They're also very power hungry.
you're right they are very power hungry . I don't know enough about crossovers to improve its design I was tempted to get a hypex fusion plate and to make it active but it already does sound very good . especially with voice. I have the active too and much prefer the passive . they have different tweeters and crossover points. the tweeter on the passive seems to have a small horn or wave guide . I think this prevents some diffraction that creates a siblance in the active version
Do you have measurement gear for obtaining the Thiele Small parameters of the woofer? Once obtained, you could then model this stuff.
Otherwise, keeping the original box dimensions in your new cabinet/plinth would be the easiest way to go.
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I googled for "Dynaudio BM15 driver" and found this photo which says it's the 24 W-100. It may or may not be correct --- you could remove your driver and have a look. Also a listing on reverb implies the same.
This one's actually in vituixcad's enclosure database -- but it models a ported SBB4 alignment of 38L for 47hz...where the BM15 specs say 43hz F3 from 28L. When I squish the volume down to 28L in vcad, it gives F3 = 49hz.
I'd think that you wouldn't want to go over 38L if you want to try increasing the box volume, and you can play with vcad to look at changing the port accordingly.
The port it gives for 38L + 47hz F3 = 15cm long, 7cm diameter.
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P.S. increasing beyond 38L in vcad doesn't lower the F3, and this driver doesn't work in a sealed box, neither (18.5L gives 62hz with qts of 0.7).
If we assume that BM15 driver is anywhere similar to 24W100, Qts around 0.3 and Vas somewhere 90 litres, then it proves that any floorstanding cabinet of internal volume at least twice as large as original BM15, should considerably improve on the bass performance, playing deeper and more articulate, assuming some experimenting with different vents.
thankyou . the driver is the 24w100 so I'll have a look at vituixcad it's not something I'm familiar with . I don't have the ability to measure the parameters at the moment so I'll start with that programme and see what happens . I would prefer a sealed enclosure even if I had to boost the low end a bit with eq . the new room has wooden suspended floors and seems to have a lot more low end gain than my larger concrete floored previous room
I'm trying to understand this programme its very interesting when I've got the hang of it be very useful thankyou . I think sometimes the specs manufactures give are inaccurate assuming the customer doesn't know how to check this stuff out . it's annoying only having a miniature window of the drivers in the database and I can't figure out how to make it bigger ?
24W100 is the same driver that i use from my latest 3 way built
https://www.diyaudio.com/community/...ild-with-dynaudio-drivers.387930/post-7098565
I use datasheet parameter and ended with 48L ported box with 8.5cm diameter pvc pipe and 21cm length. this woofer can play high where i tried 2kHz and still good sounding to match with Satori tweeter. however adding MW152 and let 24W100 only play below 300Hz really gives much better integration
because i use dsp then it's easy to change crossover, but you can play with WinISD for it's box size
https://www.diyaudio.com/community/...ild-with-dynaudio-drivers.387930/post-7098565
I use datasheet parameter and ended with 48L ported box with 8.5cm diameter pvc pipe and 21cm length. this woofer can play high where i tried 2kHz and still good sounding to match with Satori tweeter. however adding MW152 and let 24W100 only play below 300Hz really gives much better integration
because i use dsp then it's easy to change crossover, but you can play with WinISD for it's box size
there's a VERY thin window bar / line across the bottom of the pane - you have to hold down left mouse button and drag it up or down to resize it -- yes, quite fiddly
what you really want is the T/S parameters which you can also put into WinISD if you like
Here's the (ancient) datasheet - may/may not be reliable
http://nedlab.com/wp/wp-content/uploads/2014/06/24w-100_data.pdf
cool project what do you think of the dynaudio mid ? there are so many options out there I think dynaudio are starting to look a bit overpriced although I appreciate there large voice coils
i really like Dynaudio Esotec driver, compared to Satori mid/woofer which is too clean for my taste. some people here called Dyn as "fierce" which is what i'm looking for. most of my DIY fellow suggest Dyn as my choice when I tell them my experience with not being happy with some drivers that i tested
btw i'm already preparing for next project, dual 24W100 and Esotar mid/tw. but first i will replace my minidsp to Arc Audio PS8 PRO and finish multichannel amplifier
notes : on my previous link i used MW180 which i also have, due to it's higher Qts then it's not good in the box that i build, it's more suitable for closed box.
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thanks ... that will be an unbelievably cool project your obvs a bit more further along this journey than me !! I like the look of the new topping multichannel dac . which amp are you building ?
thankyou I thought you would usually be able to drag the window down I had tried but must have been just missing it ill try again ... and thanks ill have a look
I have aragon 2004 for Woofer, with it's 32Vac supply around 200W @4ohm hopefully it's adequate.
i have soldered all parts of 4 boards PeeCeeBee shaan version which will be used for Mid/Tw, but still have not finished it's chassis yet. 25Vac supply around 90W @4ohm should be enough. I'm also looking at 4 channel Babelfish XA252 to play hot class A 🙂
thanks found the datasheet online now seems like this is quite a high quality driver which I obvs suspected having listened to the speakers so long up until now