That isn't a plus. Probably better than 3/4" MDF, but not as good as 18mm ply. And bloody heavy.
The price was right thou, and you are enjoying them, so that is what counts.
dave
>>> The price was right...
They may be the only ones in existence! I would sand the rough spots smooth, paint or stain to finish them off and build a 'box' or removable baffle to mount on the front suitable to try different 8" drivers. I'd smuggle in anything from Fostex, AN and the new TB 8" is lovely and all may offer an upgrade to the B20 + tweeter. Mdf be damned... i'd find a way to keep the Hedlunds.
Godzilla
They may be the only ones in existence! I would sand the rough spots smooth, paint or stain to finish them off and build a 'box' or removable baffle to mount on the front suitable to try different 8" drivers. I'd smuggle in anything from Fostex, AN and the new TB 8" is lovely and all may offer an upgrade to the B20 + tweeter. Mdf be damned... i'd find a way to keep the Hedlunds.
Godzilla
the front plates are just as you say. they are only screwed into the original cabs and easily removable. i'm considering refinishing as a winter project. too many outdoor summer ones now.
i tried the piezo tweets today w/out the L-pad. even with 20 ohms and 3.3 mfd caps, they are way too hot for me!
so i put some old epi inverted (or non-inverted depending upon one's perspective) tweets in using the 3.3 mfd ~ 10kc. this is a better mix. very spacious and open sounding with strong bass.
The EPI tweeters are nice... even the early ugly version.
Foster has a smaller inverted dome tweeter that is even nicer (if you don't need to XO as low as the EPI is capable of)
dave
Foster has a smaller inverted dome tweeter that is even nicer (if you don't need to XO as low as the EPI is capable of)
dave
>>> i tried the piezo tweets today w/out the L-pad. even with 20 ohms and 3.3 mfd caps, they are way too hot for me!
Yes, tooooo hot that would be. Try again if you feel so inclined using 1.0uf and work up or down in small increments if you like the sound. I'm sure the EPI tweets are also good.
Yes, tooooo hot that would be. Try again if you feel so inclined using 1.0uf and work up or down in small increments if you like the sound. I'm sure the EPI tweets are also good.
most of the ones i have are the black ones w/ gold trim. there is 1 pair of the uglies in the box (as i recall).
didn't do anything but a test setup here but added another 2.2 uf in series and put the L-pads in the loop. should be 1.1 or so.
with the pads turned off and then on to just where sound emits from the tweeters is the right level for the piezos? wow, that's some sazzle/frazzle!
wonder if the below is a better one?
3-1/2" Wide Dispersion Piezo Horn Tweeter Square | Parts-Express.com
Those are the niceset, but do have a tendency to have the magnets fall off... be careful with them
dave
Hi there GM: In post #121 above, you proposed an alternative reduced volume BIB for the Pioneed BU driver, 12cf. While the graph indicates a lowered gain, the proposed partially blocked terminus also smooths the response curve over a signifiquent bandwidth. To me, smoothing would be a good result and for a "smaller" room. How do we determine (or calculate) the amount of the terminus (Sm) to block with a port? ...regards, Michael
Dunno, you'll have to get MJK or someone else that knows how to calculate it mathematically. When I did my reflex BIBs, I tuned them manually same as any other reflex since simple reflex formulas were way off on any column/tower/pipe/horn (aka MLTL/MLTQWT/MLhorn) design I did WRT vent area, length plus I would critically damp the vent as required to limit its duct/pipe harmonic's 'ringing', though if I build any more I'll just use MJK's software to calculate it since it's accurate enough based on a few old designs I still have my scribblings on.
GM
GM
did u actually build the BIB with BOFU and the tweeter combo? Any chance of pic? I saw the video and far shot...
Last edited:
gychang bofu
I did a 'gychang bofu' and find that that bofu is quite loud and forward and can't play at high volume. Maybe filling the enclosure will help?
I did a 'gychang bofu' and find that that bofu is quite loud and forward and can't play at high volume. Maybe filling the enclosure will help?
Yes I built a pair, then had "Speaker Camp" where anyone who wanted to could pay $120 help build them, and get a pair.
We made 10 pair- My 2 brothers, bro in law, and son all have them! Fun to see the BIBs at their places when I visit..
Thanks for all the wonderful information!
After reading this thread I have decided to make a set of these. I have the possibility of using 19mm MDF or 19mm 'blockboard' ('blocks' of wood sandwiched between veneer).
Could someone please explain what would be better - and why?
Also, I am in Australia and have not been able to source the Parts Express tweeter here. Can anyone suggest an item that is available in Oz? If not I will order from Parts Xpress and wait...
Thanks in advance for any assistance.
Without seeing the quality of the blockboard hard to say, but at a guess i'd use it ... that is the same kind of construction as the bamboo plywood which is amoungst the very best sheet material.
This is a better tweeter, with savings in shipping likely similar cost Mark Audio Tweeter No. 3 - No Logo - PAIR
Do you have a set of BOFU already?
dave
This is a better tweeter, with savings in shipping likely similar cost Mark Audio Tweeter No. 3 - No Logo - PAIR
Do you have a set of BOFU already?
dave
Thanks for your quick reply Dave, together with all the other information that you have presented here - without which I wouldn't have got 'hooked' into a BIB project!
I have just bought a set of BOFU's off eBay and will buy the tweeters you recommended. A customer with a woodworking shop has offered to make the speakers - I will now check that he is okay with using blockboard.
Planning to use these in a mid size room with 12 ft high ceilings.
Will report back as to how it all goes in a few weeks. Thanks again! Lloyd
Having recently built the Pass Amp Camp Amplifier (ACA) I got interested in building a BOFU in BiB. The original Pioneer BOFU has been discontinued but Parts Express quotes the GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW as a substitute http://http://www.parts-express.com/pe/showdetl.cfm?partnumber=292-430
Has anybody tested and tried it? Is it a worthy successor to the original BOFU?
Has anybody tested and tried it? Is it a worthy successor to the original BOFU?
- Status
- Not open for further replies.