Hello Scott , I built a pair of Harveys 1v1 and was so impressed that I thought that I would try a pair of Bruce 1v2 with a pair of 206e that I had. At the moment the Harveys sound much better. The 206E/Bruce needs a correction circuit or filter. Can you please advise me on this. Here is a pic of the Harveys.
Thanks , Les Hudson
Thanks , Les Hudson
Les,
Because it is a pyramid, the taper is actually quadratic, not linear, which does put them into the Metronome camp... cool that you came up with them independently.
Can you post size details? I'd like to put that into the Metronome database.... FF85KeN is right at the top of the list of my favorite drivers, and the Met i currently have is very short to be used as a mid-tweeter to be set on a bass cabinet.
dave
Because it is a pyramid, the taper is actually quadratic, not linear, which does put them into the Metronome camp... cool that you came up with them independently.
Can you post size details? I'd like to put that into the Metronome database.... FF85KeN is right at the top of the list of my favorite drivers, and the Met i currently have is very short to be used as a mid-tweeter to be set on a bass cabinet.
dave
Exterior size is 60.5" tall , 2" x 2" at the top , 5 5/8" x 5 5/8" at the bottom. Wood 3/4" thick. 5 liters internal volume. Port 1.75" dia. hole located 12" from internal bottom , 1oz. polyfill covering from top to 35" down. Driver 27.75" from internal top to driver center. I'm still experimenting with supra baffles and such.
Les Hudson
Les Hudson
Need Help Fostex 206E BSC circuit
I built a pair of Harvey 1V1 with a monocor 4" and was so impressed that I had to build a pair of Bruce 1V2/ 206E. At the moment the Harvey sounds much better than the Bruce. I need advice on a filter for the 206E. I would prefer to do this at line level between Pre-amp and SET2A3 amplifier. Thanks , Les Hudson
I built a pair of Harvey 1V1 with a monocor 4" and was so impressed that I had to build a pair of Bruce 1V2/ 206E. At the moment the Harvey sounds much better than the Bruce. I need advice on a filter for the 206E. I would prefer to do this at line level between Pre-amp and SET2A3 amplifier. Thanks , Les Hudson
Thanx for that Les.
Note that what you need is likely not BSC but the series R i have already mentioned. Bruce was designed for FE207, and the Q of the 206 needs to be raised to make it work properly. Working properly the gain of the box is such that little or no BSC is required.
dave
BTW: Scott is quite scarce at the moment. His dad is quite ill.
Note that what you need is likely not BSC but the series R i have already mentioned. Bruce was designed for FE207, and the Q of the 206 needs to be raised to make it work properly. Working properly the gain of the box is such that little or no BSC is required.
dave
BTW: Scott is quite scarce at the moment. His dad is quite ill.
Edit -Dave beat me to it.
V. little audio time at the moment, but the box was designed for the 207, not the 206 & can do little to compensate for the latter's rising response above ~1.5KHz. That's not step-loss, but inherent to the driver as Dave mentions above. A few ohms of series resistance as suggested might help, although you're likely to have ~equivalent of 2.5ohms already with that SET 2A3. A speaker level shelving filter would be on the lines of 4ohms paralleled with a 0.5mH inductor. Bit of toe-in might help. Line level, I wouldn't like to say, I rarely work with passive components at line level & the values, just as at speaker level, will depend on the electrical characteristics of the components at each end, in this case the pre & power amps rather than power amp & speaker.
V. little audio time at the moment, but the box was designed for the 207, not the 206 & can do little to compensate for the latter's rising response above ~1.5KHz. That's not step-loss, but inherent to the driver as Dave mentions above. A few ohms of series resistance as suggested might help, although you're likely to have ~equivalent of 2.5ohms already with that SET 2A3. A speaker level shelving filter would be on the lines of 4ohms paralleled with a 0.5mH inductor. Bit of toe-in might help. Line level, I wouldn't like to say, I rarely work with passive components at line level & the values, just as at speaker level, will depend on the electrical characteristics of the components at each end, in this case the pre & power amps rather than power amp & speaker.
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I tried adding 1 - 4 ohm resistor , equalization and I've given up on using the 206E in the Bruce Horn. I have a pair of 10" audio Nirvanas that look like better canidates for the Bruce Horn. I will try them. Here are the Nirvana specs if you have time to model them in the Bruce 1V2. Thanks , Les Hudson
www.baysidenet.tv/catalog/pdf/super10.pdf
www.baysidenet.tv/catalog/pdf/super10.pdf
The chart in the drawing gets us in trouble again. And it points out the need to push a revision of the Span pages to the top of the queue.
The doc says FE207e, the Plans page suggests Hemp Acoustics FR8 can also be used. Looking at the chart FE206e looks OK (and people have built and been happy with FE206 with series R). There has been a lot of discussion on what works and how it works on these pages.
The original BVRs have all been superceded by the Changs.
dave
There is then a good chance that they will.... no other changes but to increase the size of the hole to fit. It will be tight and splash off the sides could affect the midrange.
Did you check for other potential issues? Leaks, play with damping, get at least 100 hours on the FE206? What did you build the box out of?
dave
Absolutely no leaks. I added a 1.25" dia wooden dowel from side to side across the center of the compression chamber. I also used dowels in place of the mouth braces. Constructed of 3/4" MDF , in some cases I prefer to Birch in situations where system is too bright (which is the case here). I had the 206E drivers in Hedlund Horns for 5 yrs , well broken in. They also have socket phase plugs. I tried the cc full of polyfill and half filled with poly fill. I ran sweeps and there is bass at 35hz but the bass is so out of balance with the mid/hi.
I loaded some 8" accordian surround Eminence drivers and it sounded much better but no highs. Les Hudson
I loaded some 8" accordian surround Eminence drivers and it sounded much better but no highs. Les Hudson
You may well need a BSClike filter then. Martin King has a good article, and Paul Joppa has a PLLBSC circuit you can use before your amps.
Dowels don't make very good braces, and being made of MDF they will need more bracing not less than aif they were made from a good multi-ply or as a substitute for bracing an additional layer of material.
dave
Dowels don't make very good braces, and being made of MDF they will need more bracing not less than aif they were made from a good multi-ply or as a substitute for bracing an additional layer of material.
dave
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