I believe that the original D26 series tweeter was 4 ohm... Try to verify that... If it is, put a 2 ohm resistor in series (positive lead) with the tweeter. This will do 2 things: help to bring the crossover frequency back to its original design and it will pad the tweeter a hair to help take care of the brightness that you speak of... again, I am going by memory of that tweeter being 4 ohm, check it out, if it is this inexpensive part will help,
Tim |
Sorry, don't know what I was thinking, the resistor would be putting a 6 ohm in place of an 8 ohm, not a 6 ohm in place of a 4 ohm, please disregard my last post, I'll research and see what I can find about the original D26 tweeter. Tim |
Ejvic,
This can be reverse engineered and a decent dome can definitely be found. I would need to see the crossover. I've done some looking for you... this is a guessing game.
Hales are 88db 4 ohm speakers, I cannot find a spec sheet on its original tweeter anywhere, one forum said that it had a very low fs... (around 500). Most domes of that era had a slight to relative high end rise...
So here you go, basically, if the crossover does not have any pad on the tweeter, meaning the original tweeter was 88 db 4 ohm, Parts Express has The Dayton RS28F-4 (silk dome mid 500's FS) slightest high end rise, should be a drop in.. don't know about fitting in the cabinet. This is built for Dayton by Usher and is one of the better Dayton tweeters....
If you can take a look at the crossover and get resistor values on a pad, if there even are any, we can get very close, but my guess is that a Vifa of this era should not be more than 91 to 92 sensitivity... Madisound has a SB Acoustics SB25AC-C000-4. This dome has similar characteristics, but is 91+ sensitivity 4 ohm, but has a 700FS. I have not found crossover points or slopes.
These are both budget domes at around $50 each, Let me know where the budget is and I can take another look, but seeing that the vifa that you dropped in there is around 87.5 sensitivity with a higher fs and is 6 ohms, I would think that the Dayton would be a very good alternative.
I hope this helps, Tim |
Ejvic,
I was able to look up the Seas T29MF001 shown as recommended by Madisound above... It was a 92db 4 ohm sensitivity tweeter. Selling now for about $250 U.S. If Madisound is correct, that means that your Hales have a tweeter pad (tweeter volume is turned down)... but if that is the case, it would affect your 87.5db 6 ohm vifa that you are now using and it would sound dull... if I recall one of the treads above, it gets bright on occasion, which leads me back to telling you to buy the Dayton RS28F-4 from Parts Express. I can most likely find others, but I think you will find this a nice sounding alternative, good luck,
Tim |
this is not a "Hales tweeter"... made by Vifa D26-38-04... Thiel used it a bit also... |
Ejvic,
Once installed give them 40 to 60 hours before getting critical... the worst thing you would need is to change 1 or 2 resistors in your crossover, You will get these to blend quite well. I'll be glad to help with that if you can get the info from your crossover and do the work.
Tim |
Hi ZD542,
Not on the binding post... a single resistor will add resistance to the speaker, if added to the tweeter, it will add resistance to the tweeter. If Hales used a single resistor in the crossover as a pad, the resistor is figured into the crossover frequency, If he used 2 resistors as an l-pad, we can simply change these 2 resistors without effecting the crossover at all.... of course, there is a shot that the tweeter sounds pretty good without mods. |
Ejvic, don't worry about the crossover... mount the tweeter, get a good listen.... then we can worry about changes if your not happy. I suspect that it will be pretty good... and if the earlier post on the Seas tweeter was correct, we may need to completely remove a resistor or 2.... |
Ejvic,
I hope that you did indeed buy the F version (not A version) of the tweeter that I recommended.... I've been researching the Hales info extensively. I have a photo of the crossover and I'm sorry to say now, but I have found a replacement diaphragm for the tweeter....
Here is the diaphragm: http://www.madisoundspeakerstore.com/scanspeak-voice-coils/scanspeak-voice-coil-d3004/
The good news is that the Dayton RS-28F-4 is still a reasonable replacement, it should cross well and it will be down about 1.5 DB from the original tweeter, You may love it you may want to change a resistor... to correct. Or, Scan Speak now owns Vifa, this is supposed to be the correct diaphragm...
Don't say "now you tell me" took a lot of time to find this info. Tim
The |
No, the Dayton F model is not lower in sensitivity than the Vifa that you have in there now, it is actually about the same, but the impedance is a much closer match to the original D26 series "Hales" vifa, so it will cross properly and hopefully get rid of the peak that you are dealing with.
If not the photo's that I have of the Hales crossover show it being fairly simple, I would just need to know how you would want it to change and need a shot of both sides of the board. as long as you can do the work, you will end up with a great blend. |
Been about 10 Days, I assume no news is good news. Are you a happy camper? Uh, happy audiophile? |
