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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Lance Qu on May 23, 2011, 03:46:02 AM
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Hi Guys, i am new here.this is my first post.
I would like to talk about the BassBoxPro 6 as I am learning about it.
Can some one give some suggestion to apply it well ??
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Hi Guys, i am new here.this is my first post.
I would like to talk about the BassBoxPro 6 as I am learning about it.
Can some one give some suggestion to apply it well ??
Try and understand what all of the different graphs mean, and what consequences they may have for your desired results.
I find the Xmax graph very useful for designing sub-woofers.
I normally turn on the vent resonances option.
If a driver in the database is lacking in parameters, sometimes you can find it online, and sometimes, there are enough for Bass Box to calculate.
I always find that Bass Box Complains about most factory Parameters a little, perhaps its because reality, is less perfect than the math?
Do you have specific questions?
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Try and understand what all of the different graphs mean, and what consequences they may have for your desired results.
I find the Xmax graph very useful for designing sub-woofers.
I normally turn on the vent resonances option.
If a driver in the database is lacking in parameters, sometimes you can find it online, and sometimes, there are enough for Bass Box to calculate.
I always find that Bass Box Complains about most factory Parameters a little, perhaps its because reality, is less perfect than the math?
Do you have specific questions?
Thanks for your reply,Antone.
what does the "Room" for ?? the curve always seems to be a smooth one for my many designs.
and the "Mechanical Configuration" for the driver(one driver) only offers one for choice ,the normal configuration,what can i do if i want to choose other configurations.
hope to get help from you.
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Thanks for your reply,Antone.
what does the "Room" for ?? the curve always seems to be a smooth one for my many designs.
and the "Mechanical Configuration" for the driver(one driver) only offers one for choice ,the normal configuration,what can i do if i want to choose other configurations.
hope to get help from you.
I don't know if there is a way to change Room effects. I need to reinstall the software but, normally it treats the box like its in Half Space. Which is useful for bass cabinets or subwoofers unless you are flying them in the air.
The Mechanical Alignment is for even sets of drivers. You can either run normal or Push Pull. Push pull reduces 2nd order harmonic distortion in the lower frequencies. You just need to remember to reverse the phase of the reversed Driver so the cones both move the same way. Otherwise you'll end up with a subwoofer thats great a canceling Fundamental pitch leaving harmonics and mechanical noise.
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I have found the Group Delay chart an interesting tutorial on the impulse response differences between the box designs - reflex v. bandpass, etc..
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I don't know if there is a way to change Room effects. I need to reinstall the software but, normally it treats the box like its in Half Space. Which is useful for bass cabinets or subwoofers unless you are flying them in the air.
The Mechanical Alignment is for even sets of drivers. You can either run normal or Push Pull. Push pull reduces 2nd order harmonic distortion in the lower frequencies. You just need to remember to reverse the phase of the reversed Driver so the cones both move the same way. Otherwise you'll end up with a subwoofer thats great a canceling Fundamental pitch leaving harmonics and mechanical noise.
i found the driver data base is out of date. some famous brands are not there. and the modle No. are different from what they are now ...
is there any patch to update the database ?? or do i need to input data to update
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I have found the Group Delay chart an interesting tutorial on the impulse response differences between the box designs - reflex v. bandpass, etc..
the peak is 31.8Hz for my design, reflex sub. :)
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i found the driver data base is out of date. some famous brands are not there. and the modle No. are different from what they are now ...
is there any patch to update the database ?? or do i need to input data to update
Latest driver database update is 2/23/10. You can enter the TS parameters (either measured directly or from manufacturers' websites) for other drivers and save them into the database.
http://www.ht-audio.com/pages/BassBoxPro.html (http://www.ht-audio.com/pages/BassBoxPro.html)
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the peak is 31.8Hz for my design, reflex sub. :)
The "Peak" or longest Group Delay normally happens at Port tuning.
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Hey Lance, do you rely soley on manufacturers T/S specs or do you measure them yourself? I find supplied specs to be off in quite a few cases.
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Hey Lance, do you rely soley on manufacturers T/S specs or do you measure them yourself? I find supplied specs to be off in quite a few cases.
Depends on the manufacturer and how good their specs are. I like that eminence gives a response curve up above bass region, for most of the drivers. I've never spent the time trying to generate my own. That takes well calibrated test equiment, and repeatable measurement conditions.
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Latest driver database update is 2/23/10. You can enter the TS parameters (either measured directly or from manufacturers' websites) for other drivers and save them into the database.
http://www.ht-audio.com/pages/BassBoxPro.html (http://www.ht-audio.com/pages/BassBoxPro.html)
thanks George, the link is very helpful to me ,thanks very much
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The "Peak" or longest Group Delay normally happens at Port tuning.
the longest group delay is 18msec at 31.8hz
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Hey Lance, do you rely soley on manufacturers T/S specs or do you measure them yourself? I find supplied specs to be off in quite a few cases.
Hi Jeremy, i got most of the T/S specs from manufacturers' web. some i measured myself ,like the depth or lenght of transducer, every manufacturers' supplied information ,not enough.
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Depends on the manufacturer and how good their specs are. I like that eminence gives a response curve up above bass region, for most of the drivers. I've never spent the time trying to generate my own. That takes well calibrated test equiment, and repeatable measurement conditions.
Hi Antone, i have a question, may i use the BassBx Pro 6 for full-range speakers ?? I want to try the eminence HF for my 12inch , i like the eminence 2002 HF transducers. what do you think BassBox Pro6 for designing full-range
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Depends on the manufacturer and how good their specs are. I like that eminence gives a response curve up above bass region, for most of the drivers. I've never spent the time trying to generate my own. That takes well calibrated test equiment, and repeatable measurement conditions.
Hi Antone, i have a question, may i use the BassBx Pro 6 for full-range speakers ?? I want to try the eminence HF for my 12inch , i like the eminence 2002 HF transducers. what do you think BassBox Pro6 for designing full-range
Lance,
BassBox Pro 6 will work fine for designing the cabinet and port dimensions for a top cabinet, but will not predict port resonances, cone breakup and upper peaks that the speaker will have.
In a sub, the port resonances and cone breakup are well above the passband, in a full range box the port resonance can easily be in the passband, and cone breakup also within the passband if too high a crossover is chosen.
I sent a PM to you regarding PSD2002 I have for sale.
Art Welter
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Hi Antone, i have a question, may i use the BassBx Pro 6 for full-range speakers ?? I want to try the eminence HF for my 12inch , i like the eminence 2002 HF transducers. what do you think BassBox Pro6 for designing full-range
The 2002 has a roll off a little lower than I would like in the HF, the 16 ohms may or may not help in not needing as large of a pad to match spl's but making a crossover that actually performs well requires measurement and listening tests. One can use the xover design software as a starting point but you will seldom get what the xover software predicts in the real world.
I really nice high frequency transducer that I is the B&C DE250 or what ever the newest version of that transducer is, it has nice linear extended HF response.
As far as designing a full range box I've done some 3 way boxes, some of which predicted very nicely and others which had unexpected consequences due to baffle diffraction effects. You can find a good starting point but like Art said cone breakup and some other things can't be predicted with bass box.
Or polar behavior at xover.
I do think that a 2 way with a single twelve will be better than a single 15 but I think its still a little bit of a compromise with the low cut of the 2002 compression driver. I normally try to not xover at the low cut, imo compression driver horn combos sound bad if they are driven the absolute low cut. And I think 12's start beaming above 900Hz.
But its all a compromise at some point, and its all about what compromise works best for you.
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Hi Antone, i have a question, may i use the BassBx Pro 6 for full-range speakers ?? I want to try the eminence HF for my 12inch , i like the eminence 2002 HF transducers. what do you think BassBox Pro6 for designing full-range
Lance,
BassBox Pro 6 will work fine for designing the cabinet and port dimensions for a top cabinet, but will not predict port resonances, cone breakup and upper peaks that the speaker will have.
In a sub, the port resonances and cone breakup are well above the passband, in a full range box the port resonance can easily be in the passband, and cone breakup also within the passband if too high a crossover is chosen.
I sent a PM to you regarding PSD2002 I have for sale.
Art Welter
I was playing with a miniature bandpass design that predicted out of band port resonances around 10dB louder than the pass bands response.
And they where pretty accurate to what Bassbox predicted.
I think the only way to tame it would be to use some parametric cuts on a dsp controller.
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Hi Antone, i have a question, may i use the BassBx Pro 6 for full-range speakers ?? I want to try the eminence HF for my 12inch , i like the eminence 2002 HF transducers. what do you think BassBox Pro6 for designing full-range
Lance,
BassBox Pro 6 will work fine for designing the cabinet and port dimensions for a top cabinet, but will not predict port resonances, cone breakup and upper peaks that the speaker will have.
In a sub, the port resonances and cone breakup are well above the passband, in a full range box the port resonance can easily be in the passband, and cone breakup also within the passband if too high a crossover is chosen.
I sent a PM to you regarding PSD2002 I have for sale.
Art Welter
I was playing with a miniature bandpass design that predicted out of band port resonances around 10dB louder than the pass bands response.
And they where pretty accurate to what Bassbox predicted.
I think the only way to tame it would be to use some parametric cuts on a dsp controller.
Interesting. I have not actually used Bass Box Pro, just have looked at lots of charts generated by the program, and had never seen any port resonances shown. Wrong ASSumption on my part that the program does not show port resonance.
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I was playing with a miniature bandpass design that predicted out of band port resonances around 10dB louder than the pass bands response.
And they where pretty accurate to what Bassbox predicted.
I think the only way to tame it would be to use some parametric cuts on a dsp controller.
Interesting. I have not actually used Bass Box Pro, just have looked at lots of charts generated by the program, and had never seen any port resonances shown. Wrong ASSumption on my part that the program does not show port resonance.
Yah its a little tab you can turn on, and I must say I have seen close to predicted resonances most of the time.
I don't know if I have any of the sweeps still But the resonance actually resembled an asymptote on the tef sweep, as predicted in bassbox.
I'll have to look at it again I think it has a little baffle prediction, and a little room size prediction (for cars and small rooms I think).
Its a slick little program.