R-Carpenter said:
Are the braces evenly spaced?
And i see you missed an opportunity to brace the magnets against the holey braces... you might try wedging something stiff between the magnet and the brace (it is a bit tricky to get the exact thickness -- you want enuff to provide loading but not ebuff that you overly stress the basket)
dave
planet10 said:
I thought about interlocking the magnets but this speaker is a center channel. I think it’s already overkill. I am starting my own version of PMS-Grand Utopia-Kharma 7 foot tall speaker and I will definitely give more thought to a better bracing, including interlocking backs of the magnets. I would think that a hollow MDF cup, hugging the back of the magnet should be sufficient without stressing the basket at all. All though I was toying with the idea of the compound (isobaric) configuration for the base drivers.
Brasses are spaced equally. It makes setups on the table saw easier.
R-Carpenter said:
It only takes one picture (if you still have questions after that i can split these posts off to a new thread)... attached is a picture of a brace dead centre with the even order panel modes "illustrated on top" The brace does nothing to stop the resonances that have zero crossing at the brace. With 2 braces evenly spaced you have to extrapolate to the odd modes (which are harder to get going)
dave
Attachments
Planet, the speaker box itself is very stiff. I understand the picture but in actuality, you are saying, “hey your braces are useless”. I can play this speaker at a rather high level and if you place our hand on it, it doesn’t vibrate at all. Of cause there’s also stuffing and acoustic foam inside which wasn’t pictured. Besides, cross-brace is not evenly located but rather 35/65 towards the front panel.
Are you talking about eliminating standing waves with an elaborate use of interlocking braces and different size holes?
Are you talking about eliminating standing waves with an elaborate use of interlocking braces and different size holes?
R-Carpenter said:
I'm not saying that at all... i'm just saying that they are not optimally placed... something to keep in mind for next time. (and an opportunity to point this out to anyone watching and learning)
Your bracing divides the larger panels into 3 equal but much smaller panels. Panel resonance goes up by a factor of 3 in frequency which makes them ~9 times less likely to get excited -- that is quite a bit, have no doubt it is effective. A bit better result ican be obtained if you divide the larger panel into unequal sub-panels. That way if one panel starts moving the others aren't reinforcing it because they are the same. ie in yours, if one subpanel starts moving all 3 do for 3x the output compared to what 3 unequal panels would output.
Just a little detail that squeezes a bit more out of a ptoject, and we are all working to squeeze that last bit of perfomance.
dave
I understand your point a bit better now, Dave and I completely agree with you. I also think that with the cross-brace the upper and lower panels are broken in to 6 sections not 3. My assumption is that in this particular case (sealed box), standing waves would present a bigger problem then a box resonance. Again, it’s a porously build speaker (center channel) and it’s not designed to reproduce very low end that would normally present a bigger problem in terms of box resonance.
The ProAc clone that I build a while ago (bored with it and will be looking to unload soon) I went as far as laminating different density materials to get to 1-inch thickness
and asymmetrical bracing internally.
So there’s no limit to how far we can go in squeezing this last bit of performance out of the project and rightfully so.
The ProAc clone that I build a while ago (bored with it and will be looking to unload soon) I went as far as laminating different density materials to get to 1-inch thickness
and asymmetrical bracing internally.
So there’s no limit to how far we can go in squeezing this last bit of performance out of the project and rightfully so.
planet10 said:
Dave not all waves travel normal to the bracing - that is, not perfectly horizontal or vertical. The easiest point in which to damp the resonance or wave is during min pressure/max velocity and that's depicted on the sine as the mid point between the peaks. If you fix the frequency but change the direction then evenly spaced bracing is more effective than your illustration might suggest.
BTW I'm not disagreeing with you. Random bracing is better.
some of you guys know how to build cabinets ...
i browsed the last 20 pages or so of this thread and some of the cabinets are extremely impressive ...
but as far as actual systems go ... im not impressed. didn't see a single system that i would actually want to place in my living room. of course i don't have any system in the living room ... it would be quite expensive to adequately cover such a space and rather than to have something substandard there i decided to have nothing at all.
also a lot of you need to buy a new TV or stop watching TV altogether ... those CRTs are depressing ... its like being in the same room with a dead person ... as soon as you see such a TV immediately a question springs to mind - am i having some kind of a nightmare ?
i browsed the last 20 pages or so of this thread and some of the cabinets are extremely impressive ...
but as far as actual systems go ... im not impressed. didn't see a single system that i would actually want to place in my living room. of course i don't have any system in the living room ... it would be quite expensive to adequately cover such a space and rather than to have something substandard there i decided to have nothing at all.
also a lot of you need to buy a new TV or stop watching TV altogether ... those CRTs are depressing ... its like being in the same room with a dead person ... as soon as you see such a TV immediately a question springs to mind - am i having some kind of a nightmare ?
troll alert
sounds like you have lofty standards. Why not offer up what your "dream" system would be...if it even exists, rather than take random potshots at others endeavors???
Maybe you could point out the flaws in others systems as well. That would be endearing too...
Inquiring minds want to know...
John L.
vasyachkin said:
sounds like you have lofty standards. Why not offer up what your "dream" system would be...if it even exists, rather than take random potshots at others endeavors???
Maybe you could point out the flaws in others systems as well. That would be endearing too...
Inquiring minds want to know...
John L.
vasyachkin said:
Vasyachkin
There's some hardwork gone into everything shown in this thread.
Whilst there's nothing saying that you can't comment on peoples setup, it should be common sense that its done in a tasteful and polite manner.
In future I'd ask you to keep comments like that to yourself please.
vasyachkin said:
I tell you what buddy. I am a commercial furniture maker (memo, not a cabinet maker) and build very high-end pieces that sell from $3200 per chair to a 50k dining room table.
Why don’t you design a speaker system to your standard and I give you a great deal and build it for you. Is this my correct understanding that you aren’t happy with the appearances? So what is your preference, French art deco with ivory inlay, may be Biedermeier in French walnut? I have a good source of Amboyna veneer. I could get it at a great price of $25 a foot. I mean, just shoot your idea. Calamander may be? I am sure we could come to mutually contented price.
You haven’t even heard any of these systems but you are not impressed? I’d be very curious to hear perhaps not all of them but quite a few. I mean Shins LGTs are nothing to pi..s on even with my shop and experience with tools and materials. Are you planning to outdo him?
CRTs are fine. I am 10 ft. away from it and with component BGY, wiring it looks great.
Are Blue Rays and HDTV better? Yes but there hasn’t been too many movies out yet that I want to watch in HDTV that badly. Besides, it appears that in a year or two we will have laser TVs with even higher resolution.
Considering the res of my system, can you tell me who is singing on the background in Alien Resurrection, while Algine is having drink with Perez?
“Drink Algine?”
“Constantly”
i would never pay somebody to build cabinets for me to use at my own place because i never had a problem with prototype-looking boxes in my room. i spent several years with speakers that had no finish on them at all and right now have a subwoofer next to me that also has no finish ( just bare plywood ) which i plan to keep using for a long time in just this state.
on the other hand to design some kind of custom speakers for sale ... i can come up with some seriously messed up projects to build.
as far as TVs go ... i dont watch TV and i dont watch movies. i only watch documentaries in Divx format and usually i watch them on my computer. i do have a nice HDTV in the living room ... i turn it off whenever i have the chance but somebody always turns it back on. its completely useless but at least it looks good. things should either be useful or look good. any speakers i build should sound good enough that their looks would not matter, otherwise they're not worth building.
on the other hand to design some kind of custom speakers for sale ... i can come up with some seriously messed up projects to build.
as far as TVs go ... i dont watch TV and i dont watch movies. i only watch documentaries in Divx format and usually i watch them on my computer. i do have a nice HDTV in the living room ... i turn it off whenever i have the chance but somebody always turns it back on. its completely useless but at least it looks good. things should either be useful or look good. any speakers i build should sound good enough that their looks would not matter, otherwise they're not worth building.
pretty big 3 way
I made 3 way, based 15" Monacor, TRUVOX-0510 middle and Fountek CD2 ribbon. I'm always made it by real marble, that's why view is good. I hope
special thanks to LoudSpeaker LAB for crossover design help. this software allow me to load measurement result to programm and based this to fit a crossover components.
so, I'm satisfied with sounding and appearance
I made 3 way, based 15" Monacor, TRUVOX-0510 middle and Fountek CD2 ribbon. I'm always made it by real marble, that's why view is good. I hope
special thanks to LoudSpeaker LAB for crossover design help. this software allow me to load measurement result to programm and based this to fit a crossover components.
so, I'm satisfied with sounding and appearance
An externally hosted image should be here but it was not working when we last tested it.
vasyachkin said:
agreed.
however the speakers here not only look good but sound good (atleast to the owners). I dont see any harm in that, in my view the effort (in making a loudspeaker that sounds and looks good) should be applauded.
Given the choice between 2 loudspeakers that both sound good which one would you prefer? I know this is ahypothetical question, then again your statement "but as far as actual systems go ... im not impressed. didn't see a single system that i would actually want to place in my living room" was just as hypothetical.
ATM, I'm still reconstituting it all. Mostly semi vintage eBay stuff.
Pictured is a cheap Audio Research Tech 341 dual 15 band EQ.
DBX 3bx-DS
Kenwood Basic C2
Kenwood Basic M2 amp
And on the left is the reason why I'm here looking for help with a 4 way project. POS bookshelfs - 4 1/2" woofs, 3/4" tweets, ported.
Not Pictured (no reason to hook 'em up for lack of good speakers).
Yamaha T-85 Tuner
DBX 120X-DS
Yamaha DSP-100U
Kenwood Basic M2A
Pictured is a cheap Audio Research Tech 341 dual 15 band EQ.
DBX 3bx-DS
Kenwood Basic C2
Kenwood Basic M2 amp
And on the left is the reason why I'm here looking for help with a 4 way project. POS bookshelfs - 4 1/2" woofs, 3/4" tweets, ported.
Not Pictured (no reason to hook 'em up for lack of good speakers).
Yamaha T-85 Tuner
DBX 120X-DS
Yamaha DSP-100U
Kenwood Basic M2A
