The pioneer bofu is gone and I'm looking to try a g chang or curvy chang build. I'm looking for a cost effective alternative.
PE has this woofer from pioneer:
Pioneer B20GR30-51F 8" Butyl Surround Woofer
It specs out a little different from the Bofu (qts) but is quite efficient and looks to have a very similar motor structure.
I noticed on this forum that a lot of guys have removed the whizzer cone and added a helper tweeter to the Bofu anyway.
So my question is three fold:
1) Is this a suitable alternative to the Bofu assuming the use of a tweeter?
2) Are there other alternatives that are cost effective for the g chang or curvy chang?
3) What tweeter would I use as a good match?
I know that GRS has a "Bofu type" driver on PE, but I have no experience with GRS.
I'm also aware that this is essentially a two way post in the full range section, but this seemed like the place to ask considering I talking about building a chang.
Thanks in advance.
PE has this woofer from pioneer:
Pioneer B20GR30-51F 8" Butyl Surround Woofer
It specs out a little different from the Bofu (qts) but is quite efficient and looks to have a very similar motor structure.
I noticed on this forum that a lot of guys have removed the whizzer cone and added a helper tweeter to the Bofu anyway.
So my question is three fold:
1) Is this a suitable alternative to the Bofu assuming the use of a tweeter?
2) Are there other alternatives that are cost effective for the g chang or curvy chang?
3) What tweeter would I use as a good match?
I know that GRS has a "Bofu type" driver on PE, but I have no experience with GRS.
I'm also aware that this is essentially a two way post in the full range section, but this seemed like the place to ask considering I talking about building a chang.
Thanks in advance.
Not a bad idea at all to find another driver that would work in the Chang. And yes, it was typically implemented with a tweeter anyway. But i'd bet that Pioneer driver will be gone too in time. Did i read somewhere that Pioneer is not going to sell raw drivers anymore? I am not sure if that's the case.
I haven't heard that. These seem to me to be in a great price range, have great reviews and look heavily built.
I'm no expert on what T/S parameters I need to pay attention to specifically for the chang.
Any help would be appreciated.
On a side note I'm also thinking of re-creating my first pair of good speakers with these woofers just for fun. Dahlquist M-905.
I'm no expert on what T/S parameters I need to pay attention to specifically for the chang.
Any help would be appreciated.
On a side note I'm also thinking of re-creating my first pair of good speakers with these woofers just for fun. Dahlquist M-905.
When looking at T/S the most important are Fs, Qt, Vas. Use the Fostex FE207e as a baseline.
dave
You're going to need more than a super tweeter with that woofer. Even though its frequency response goes out there, you can be sure it doesn't sound very good above maybe 1KHz. Go and look at the frequency response graph. Even if it did have a smooth extended frequency response, it would still beam like crazy in the higher frequencies. Get a tweeter that can crossover low, like maybe 2KHz.
http://www.parts-express.com/pdf/290-042.pdf
http://www.parts-express.com/pdf/290-042.pdf
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The visiton b 20 looks interesting and fits within efficiency and FS. Vas is almost double though. The driver also specifies that it is geared towards pro sound. That makes me wonder about low spl bass response.
Any other recommendations?
Thanks for the post on the PE test results on the pioneer woofer. It does seem mildly ragged over 1500hz and rather terrible over 2000hz. I knew I would need more than a helper tweeter for something like this.
What what do you think of the HiVi tweeter listed above? Any alternatives?
I am under the impression that the benefits of the chang designs are primarily under 2000hz in which case crossing at 2000hz seems like the ticket.
Any feedback welcome? Thanks.
Any other recommendations?
Thanks for the post on the PE test results on the pioneer woofer. It does seem mildly ragged over 1500hz and rather terrible over 2000hz. I knew I would need more than a helper tweeter for something like this.
What what do you think of the HiVi tweeter listed above? Any alternatives?
I am under the impression that the benefits of the chang designs are primarily under 2000hz in which case crossing at 2000hz seems like the ticket.
Any feedback welcome? Thanks.
It certainly looks to be a good tweeter, but when making/designing a two way loudspeaker with an 8 inch woofer, you need a tweeter that will crossover quite low.
I would recommend something like the Dayton Audio DC28F-8 1-1/8" Silk Dome Tweeter, it has an fs an octave lower than the Hi-Vi.
The Dayton looks like a good candidate. Do you think I'll have an issue with matching efficiency. The HiVi specs out pretty efficient. I can alway attenuate with an l-pad if need be. My concern is that if the Dayton isn't efficient enough to keep up with the woofer where do I go from there?
You make a very good point. I didn't bother to check the efficiency/sensitivity of that Dayton tweeter. Maybe a different tweeter, one that has 1 or 2 dB more SPL.
Specs are often misleading, and the only way to match SPLs is by microphone or a sensitive ear. It's not uncommon for a 1 inch tweeter to have a greater SPL than your typical 6 or 8 inch woofer. Easy enough to attenuate a tweeter.
If you added in some BSC for the woofer then you could get away with a slightly lower SPL tweeter.
If you are going to go that far, why not something like this https://www.madisound.com/store/product_info.php?manufacturers_id=132&products_id=8585 and push the XO down to the bafflestep? (you might want something a bit more efficient as it will give a full 6 dB BSC -- or reduce the efficiency of the woofer a couple dB by treating the paper (a good idea anyway))
It would push up the cost of XO parts -- you might want to just go active -- but would move the XO from an objectionable place to one much less so.
Or just find a more extended driver... what do the wild burrows look like?
dave
Maybe he should just stick to the original design and locate a pair of BOFUs or their equivalents.
So this would be a good substitute in the G Chang then? I'm a total newb so would you just use a cap for the tweet to cut off the lows and let the BOFU run full or crossover that as well? I'm curious what people were doing with the Changs when they added the tweet if they kept the BOFU full or not ... An inexpensive alternate and possibly a good way to get my feet wet in Single Driver BLH's without dropping too much cash ...
What about the BOFU with the VIFA XT25SC90-04? I can get these for very inexpensive making the price very attractive. Crossover point could be pretty low and sensitivity is pretty close as well. I've never heard this particular version of the Ring Radiator tweet but I've heard the others and really liked them.
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