I have tried in the past the big ported box maybe we have built them in the same time (full range driver forum) .For my ears it was very good but the bass was sounded a bit hollow I think .I have built them in a smaller box 13 lt and sounded more balanced but thin (compared always to my trusted proac's tablette 50 ) and after the years they spend in their boxes I would like to give them a third chance .I was considering a MLTL like this one https://www.youtube.com/watch?v=7fxtMqj3UWA which appealed elegant to my eyes but I am not familiar with design programs and then I bump to this thread ...But I think my wife will kill me ...
Janus44, yes, the bass sounds a bit hollow in the large ported box. Nothing is perfect. The 168z in a BIB sounds good but sounded thicker thru the midrange to me than in the ported box. You can modify the sound to your liking with stuffing. For some reason in the BIB I felt the driver needed a helper tweeter whereas in the posted box there doesn't seem to be a need for one. This could be attributed to the different rooms they were in. On open baffle, the 168z just didn't do it for me.
This should theoretically be true with all BIB Vs ported, with the MLTL in-between, though still may need some baffle step compensation [BSC] whereas the BIB shouldn't.
Not surprised; when I was chasing ever lower recordings/cab tunings I also had to re-EQ the mids-HF horns, which led me to finally understanding the concept of direct current [DC], i.e. it's infinite bandwidth [BW], ergo the lower in frequency we go, the wider its BW becomes [in harmonic structure] to tonally balance it out.
GM
More help with bass bib
GM,
More on the bass bib
I am thinking tuning to 35hz (70hz on bib calculator)and making a ibib floor loaded at or near the wall with a Vb of 9.9 ft3 or less. That's a single sheet of plywood for the five Long tboards. 15.875"x 22.5"x 48". I think that should give me some flexibility on driver selection. 12" seems doable, but I would like to go 15" if it is not to compromised.
And I am starting to get analysis paralysis. I was looking at high efficiency drivers for $100 or less with low Fs and Qts. I found few options with a suitable Vas. so I increased my budget to $200 or less. I have been focusing on Fs, Qts, and Vas because that is what the bib calculator uses, but what other parameters can help me decide?
Some drivers I have been looking at
https://www.parts-express.com/dayton-audio-pa385s-8-15-pro-subwoofer-4-vc-8-ohm--295-040
https://www.parts-express.com/celes...rofessional-cast-frame-speaker-600w--294-2006
https://www.parts-express.com/celes...ofessional-cast-frame-speaker-1000w--294-2008
https://www.parts-express.com/dayton-audio-pa380-8-15-pro-woofer--295-034
These would be crossed over to a 12" full range (https://www.parts-express.com/celes...ge-professional-woofer-driver-8-ohm--294-2082)
any help would be appreciated
Thanks
GM,
More on the bass bib
I am thinking tuning to 35hz (70hz on bib calculator)and making a ibib floor loaded at or near the wall with a Vb of 9.9 ft3 or less. That's a single sheet of plywood for the five Long tboards. 15.875"x 22.5"x 48". I think that should give me some flexibility on driver selection. 12" seems doable, but I would like to go 15" if it is not to compromised.
And I am starting to get analysis paralysis. I was looking at high efficiency drivers for $100 or less with low Fs and Qts. I found few options with a suitable Vas. so I increased my budget to $200 or less. I have been focusing on Fs, Qts, and Vas because that is what the bib calculator uses, but what other parameters can help me decide?
Some drivers I have been looking at
https://www.parts-express.com/dayton-audio-pa385s-8-15-pro-subwoofer-4-vc-8-ohm--295-040
https://www.parts-express.com/celes...rofessional-cast-frame-speaker-600w--294-2006
https://www.parts-express.com/celes...ofessional-cast-frame-speaker-1000w--294-2008
https://www.parts-express.com/dayton-audio-pa380-8-15-pro-woofer--295-034
These would be crossed over to a 12" full range (https://www.parts-express.com/celes...ge-professional-woofer-driver-8-ohm--294-2082)
any help would be appreciated
Thanks
Unless you only listen to pre-70s vinyl or similar, 35 Hz is too high a tuning to give the driver any protection since the 'port' is so big compared to a reflex's, so must be tuned to at least the lowest note it's likely to have to reproduce at any power to speak of and/or use a high pass [TT 'rumble'] filter.
Why low Qt? The lower the corner frequency, the higher the Qt ideally required plus the pipe's 3rd harmonic dip sets the ~two octave BW, so do you really want a relatively high ~120-150 Hz XO point to a 12"???
GM
Why low Qt? The lower the corner frequency, the higher the Qt ideally required plus the pipe's 3rd harmonic dip sets the ~two octave BW, so do you really want a relatively high ~120-150 Hz XO point to a 12"???
GM
GM,
Suggested Fs?
Suggested Qts?
Suggested driver for the application?
I would have these inverted and floor loaded.
Thanks GM
Suggested Fs?
Suggested Qts?
Suggested driver for the application?
I would have these inverted and floor loaded.
Thanks GM
First measurements: looks like -3dB at about 16 Hz. Decently flat response, especially at the hotseat, but seat to seat variance is bigger than with the last speaker. Big bump at 40 Hz, but looks EQ-able.
I had a shock initially, response dropped like a rock below 250 Hz, a straight line like it was drawn with a ruler. Or.... a DSP chip. Forgot to switch the receiver to direct mode and I had it hooked up to a satellite channel for measurements. My wife tells me I'm getting old and maybe she's right. F****ng buttons and settings on the d**n AVR.
I'll post some graphs later.
I had a shock initially, response dropped like a rock below 250 Hz, a straight line like it was drawn with a ruler. Or.... a DSP chip. Forgot to switch the receiver to direct mode and I had it hooked up to a satellite channel for measurements. My wife tells me I'm getting old and maybe she's right. F****ng buttons and settings on the d**n AVR.
I'll post some graphs later.
I resemble this remark. 🙁 'Santa' brought me a 9.2 chl one with lots more 'bells-whistles' than I know what to do with, so far only gotten the OTA antenna HDTV + HD audio to work correctly. 🙁 Worse, it appears a well optioned smartphone is required to get full remote control of it, which I don't have the budget for anytime soon, if ever if they stay the cost of a month car loan note, so it may be obsolete before I can have use of some options.
GM
Dunno without all the particulars of the room, system, desired personal performance, etc., just what I've already posted and that the THX LFE 80 Hz XO [or lower] has become the norm in recent times and that if positioned to take advantage of the dip, then the pipe's lower end [-6 dB] is ~two octaves lower [~20 Hz] with floor loading, room/boundary gain setting how much lower it goes with any useful output.
GM
I have tried to provide that information over the past two pages.
Oh well I am about ready to make some sawdust. I figure with box stuffing at the tip and mouth, floor loading and playing with the gap and/or adjusting vent size down to Av =Sd then I have some room to tune.
Maybe I can get them to sound musical and blend with the other drivers. I am very pleased with my first pair of BIB's
Thanks GM
That should give you a good indicator of the [lack of] available time, memory retention I currently have available and have to assume that each is only going to get shorter, so either provide specifics with Qs or others will have to help. Time for others to 'carry the torch'.
GM
GM
Yes, that's a room mode. Playing with EQ in RoomEQwizard, it seems this is easily corrected.
I am not too happy about seat to seat variance, below are three seats on the same sofa. I had succes with a dual subwoofer setup before, so I would like to try something like that with an extra BIB. Some time.
Meanwhile the wife is complaining about "out of proportion midrange" (she is picking up the lingo!), so she asked me to fix that first. I bought some second hand Ciare CH250 drive units, 10" fullrange units that got a glowing review and no less than 3 different designs in the leading German DIYaudio magazine. Always wanted to try a 10" tweeter (20 kHz response!).
I am not too happy about seat to seat variance, below are three seats on the same sofa. I had succes with a dual subwoofer setup before, so I would like to try something like that with an extra BIB. Some time.
Meanwhile the wife is complaining about "out of proportion midrange" (she is picking up the lingo!), so she asked me to fix that first. I bought some second hand Ciare CH250 drive units, 10" fullrange units that got a glowing review and no less than 3 different designs in the leading German DIYaudio magazine. Always wanted to try a 10" tweeter (20 kHz response!).
Attachments
GM,
As a newb I wanted to thank you for all the information you provide on this forum. I have a pair of BIB's that at 8 feet tall are monuments to the help you have provided me.
The attached quote is from earlier in this thread, #335. Based on the second paragraph, I am wondering if I am trying to do something I shouldn't. Can you discuss how you have done floor loaded or corner loaded bass boxes in the past? Parameters you would look for in a driver? Actual range of numbers maybe? So I can better understand low, medium, and high
I have been starting with an allowable box size and working backwards to pick out a driver. Instead of starting with the driver and calculating the box. Mainly because I am not sure what driver parameters I need to start.
Thanks again GM
Ah! Forgotten about them, there's been so many here and elsewhere.
I wouldn't, and as I've periodically posted, always vented [mass loaded] them with a vent area [Av] = driver effective piston area [Sd] per the pioneer's suggestion for max acoustic efficiency from a vented alignment. Some I did were built into the corners with ~floor-ceiling triangular plates with the vent at the floor and a stereo pair were done with a second vent at the ceiling.
Note that back then there was no low/infra-bass to speak of, so tuning was always around 27 Hz, the lowest note on a Grand Piano, which combined with the room/corner
Reverse engineering a cab is generally more trouble than it's worth unless it's a fine furniture piece unless you're a math whiz [I'm not].
Anyway, for low/infra-bass; tapped pipe, TL or horn is being increasingly used in one form or another in PA, large cinema apps and with the advent of simming programs and relatively cheap digital XO, TD, EQ modules is increasingly the norm for DIY HIFI/HT systems and since a basic TH is just a tapped BIB..........
GM
GM,
I've decided to not do the bass bib. I am going to try sealed.
But something I am not clear on is recommended driver Qts for a bib. I thought since so many successful bib's used fostex drivers that I would look for a low Qts bass driver. But as I research a little more I find some posts that indicate a higher Qts would be preferable for a (bass) bib? Target Qts for a bib?
Thanks for all the meaningful content you provide to this forum. I especially appreciate your empirical evidence.
I've decided to not do the bass bib. I am going to try sealed.
But something I am not clear on is recommended driver Qts for a bib. I thought since so many successful bib's used fostex drivers that I would look for a low Qts bass driver. But as I research a little more I find some posts that indicate a higher Qts would be preferable for a (bass) bib? Target Qts for a bib?
Thanks for all the meaningful content you provide to this forum. I especially appreciate your empirical evidence.