chris,
were you running all the maggie drivers full range or were they limited somehow?
were you running all the maggie drivers full range or were they limited somehow?
Open Baffle Epiphany!
- Thread starter cptnCanada
- Start date
any maggie experts around? wonder if the amp/pre had some crossover built into it.
i'm thinking you might be able to play around with an active crossover and get better sound. very crude version would be to use different integrated amp with each driver and use volume and tone controls to shape the sound.
OB and speaker guru martin king has posted a few times that he doesn't recommend running both drivers in an open baffle 2-way full tilt. of course depends on the drivers.
i'm thinking you might be able to play around with an active crossover and get better sound. very crude version would be to use different integrated amp with each driver and use volume and tone controls to shape the sound.
OB and speaker guru martin king has posted a few times that he doesn't recommend running both drivers in an open baffle 2-way full tilt. of course depends on the drivers.
chrisand4
Not cheap, just thrifty..
It didn't have a crossover built in, but it did have a loudness contour, which was removed when I updated the circuit and made the amp standalone.
So, I removed the large Maggie driver and flipped the baffles, I installed the Mustang driver where the other one was. I left the small driver to fill the hole (running the university by itself).
I've been listening to them this way since I made the post earlier tonight, all I can say is I hope my friend wasn't expecting to get his drivers back
These things are sounding great, I even listened to some Genesis/Rush on them and can say I'm impressed, this coming from someone that usually likes Infinities and JBLs. I really didn't think a single driver could sound so good. They aren't doing everything perfectly, but I'm typing this with a smile on my face, so that's good enough for me.
Now I want to look into building a real baffles for these drivers, I may look into other drivers/designs too, this sure is fun
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frperdurabo
AK Member
If you like the 3 piece folded baffle, plywood (birch) + piano hinges.
Excellent!
I'm not finding much on those drivers; apparently full-rangers
I'm not finding much on those drivers; apparently full-rangers
Poultrygeist
Lunatic Member
Wild Burro Audio recommends piano hinges and speaking from experience there's no rattle. Unlike door hinges they fill the gap between the panels so you don't have to tape the seams.
Poultrygeist
Lunatic Member
So you didn't like the Folding Wing OB's because the hinges rattled? Any pictures to show the assembly so maybe we could figure out what went wrong?
There's nothing to rattle with mine which require 96 screws to hold them in place. Piano hinges get their name as they're used to hinge pianos which can ill afford to rattle.
Wild Burro Audio recommends piano hinges and speaking from experience there's no rattle. Unlike door hinges they fill the gap between the panels so you don't have to tape the seams.
Is that tweet firing backwards? how do you think that is wired ?
(sorry if that is a dumb question, but certainly that crossover is minimal)
thanks.
tomlinmgt
Lunatic Member
I asked this question earlier but it never got answered so I'm going to try again as I think it relevant for all who may be dabbling in OB's. What influence does the width of the baffle have on mid-range content....say from 250 to 2500 Hz? I understand the influence width has over LF reproduction, but what are the implications above that? How does dipole effect factor in?
Thanks
Thanks
cubdog
banging through drywall
Good question. I've been told that the shape of the baffle has little significance except for having enough width to hold the baffles. That usually seems to be 20 inches or even a bit less although wider seems to be preferred if feasible. I was considering some odd shapes for my OBs and the feedback I received was that most any shape will work. How baffle shape affects the numbers is beyond my understanding.
cubdog
The width (really the entire shape) of the baffle will determine the frequency of the dipole hump. Below the hump the baffle will contribute an even 6 dB/octave roll off of the driver's SPL response. Above the hump the baffle will contribute a ripple to the driver's SPL response, if the driver is centered a significant dip in response will occur followed by the ripple. The driver selection, the shape of the baffle, and the crossover point, order, and EQ need to be traded off to get an optimum smooth and extended SPL response for both the midrange and the bass frequencies. Since they are all related, winging one of the three will only compromise the results to some extent.
tomlinmgt
Lunatic Member
Thanks, Martin. I suspected there was more to it than just mounting with a little offset and to hell with the rest. Damn.
Ok, then....how does one best address and avoid these issues when putting an unproven design together? For example....let's say I take these Beta 12-LTA's I have sitting around and would like to properly implement them in a OB design. Do I just mount them up with a little offset in a baffle, get some baseline measurements and go from there or can the T/S parameters of the driver point to some design requirements?
Poultrygeist
Lunatic Member
Those tweeters have a minimal internal crossover. This was just an experiment with not much improvement. If the tweeter is in a pod and can't radiate to the rear then rear firing is preferred.
Poultrygeist
Lunatic Member
The thing I don't understand is the plethora of designs in all shapes and sizes. Some with huge baffles, some with small baffles and some with no baffles at all. These are often the work of ordinary people giving OB a try without regard to measurements yet they love what they're hearing. The 8 year running of the "Dark Star" thread on AC forum is an example of this. These home spun OB's may be compromised in terms of hump or smooth and extended SPL yet it is often the best sound their builders have ever heard. I know how my first OB's thrashed the Zu's and all I did was copy your design without regard to using a different driver.
Personally I design everything before I buy drivers, wood, or make any cuts. I calculate the SPL response and the crossover details (active settings or passive component values) before I do anything else. I have it all designed and predicted then I start accumulating parts and assembling the system. It is very rare that I make any significant adjustments after the fact, measurements usually confirm the predictions within the accuracy of the models. I am a mechanical engineer and this is what I have been doing for a living the past 35 years, but on different consumer products.
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