Vifa BC25SC06-04 1" Textile Dome Tweeter
I used a pair of those with 420's worked well and cheap.
forum info:
Looking for Vifa BC25SC06-04 FR data
Note they are 4 ohms, but you can deal with that in the xover...
Edit: Altec used a 3 kHz xover.
Hi,
I was lucky to find a pair of vintage Altec Biflex 419. It is a wide range unit 30-15000 Hz.
I installed them in ported boxes of Wharfedale W70.
I added a twitter to complete the high end range using 1 μF capacitor.
Looking for tips if anyone has experience knowledge about this unit:
- Suitable tweeter
- Recommended box Size and kind (ported/not ported)
- Crossover and cutting points for a 2 way configuration
Thanks,
Benny
Vifa BC25SC06-04 1" Textile Dome Tweeter
I used a pair of those with 420's worked well and cheap.
forum info:
Looking for Vifa BC25SC06-04 FR data
Note they are 4 ohms, but you can deal with that in the xover...
Edit: Altec used a 3 kHz xover.
Last edited by Old Guy; June 24th, 2014 at 07:22 AM.
Your neighbors called. They like your music.
Greets!
Per an old chart, the optimum tuning is 5.6 ft^3/39 Hz Fb [Fs] with a ~4.2” dia. vent assuming ?” thick baffle [~13.854”^2 if rectangular].
This assumes a high output impedance amp being matched up to the driver’s Fs though, so with its high Qt, you may want to tune it with a 4” duct down to as low as 30 Hz [~3.2” long] if it sounds too ‘boomy’.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Thank you Old Guy & GM for you feedback.
I will try a bigger box to get the feeling and implement if parmanently if I will like how it sounds.
I'll Keep you updated
Last edited by bennyo; June 26th, 2014 at 09:46 AM.
Looking forward to it as I don't recall ever being exposed to these, only the 15"ers.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
A short update:
OK, so I did not waste any time and got creative checking it.
I opened both boxes, took the unit out of one and sealed in this box both the unit hole and the port.
Connected the boxes back to back with an improvised adaptor and sealed it with silicon.
I got an about 200 Liter box with 4" port - pictures attached.
I'm still not getting the bass I expected, very dull Low range.
I compared it to my ADS L-1290 via an AB switch, the ADS sounded much better.
I had very high expectations from the Altec unit but up to now I'm very dissapointed.
Seems like this unit should be used as mid with a dedicated woofer and tweeter and actually can not be used as wide range unit.
Any feedback on the attach is apreciated
3.jpg1.jpg2.jpg
Last edited by bennyo; June 28th, 2014 at 08:16 AM.
OK, assuming it?s truly sealed up tight, it?s tuned around 33 Hz and maybe a bit too large.
We don?t know the condition of the driver, so any speculation may be worthless.
No clue what your ADS sounds like or what you mean by a dull low range since BW limited bass typically sounds pretty bad overall. It?s only when its upper harmonics is added can we discern whether it?s ?loose?, ?tight?, etc., so wonder what condition the motor is in and/or tuned way too low and/or its suspension has stiffened up a bunch, especially the one isolating the mids driver.
Yes, all the biflexes ideally need a super tweeter for today?s recordings, ditto a ?sub? for some recordings.
Anyway, to tune it higher requires a bigger vent. A 6? will bring it to around 42 Hz. If you don?t hear much difference, then you?ve probably got a leak and it can be quite tiny and even may be coming through the woofer surround if it?s lost much of its goop over the decades from heat.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
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