Wow! Ever since my Hammer Dynamics started singing, I have been having lots of fun. Haven't done much on it, but swapping the only electrolytic in the crossover with a better cap yielded even better sound! Then I realized there's been quite some updates on the Single Driver Website's Super 12 Tweaks.
Upgrading every component in the crossover doesn't sound good to me. No, not the sound, but the idea. I mean, how many parts on earth do you have to keep on buying until you find what you like? Bleh!
However, something got me REALLY interested. That is, upgrading the tweeters from the current fabric Audax TM025F15 to the horn tweeter Fostex FT17H. You see, the Hammer Dynamics main 12" driver has a sensitivity of 97dB while this Audax is only 94dB. This explains the VERY relaxed treble. The Fostex, at 98.5dB is not only a better match, but it boasts an impressive frequency response of 5kHz to 50kHz! Wholly moley!
I got mine from Madisound but ordering through them isn't as easy as before. Previously, all it takes is a couple of e-mail messages and the goods will be on your way, but nowadays, they requested me to fax a copy of my ID AND my credit card. Reason being, too many credit card frauds. Gosh! I don't have to tell you this new procedure is a P-A-I-N. Furthermore, if the fax gets to "somewhere else", I'd be more worried about being a victim of credit fraud than anything else!
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Hey, you guys reading this, just because of a few idiots, doesn't mean all of us here are bad hats okay?
Hey, you idiots reading this, stop spoiling our reputation! (as bad as some who request free samples of integrated circuits from companies like Texas Instruments and selling elsewhere for a profit!) Shame on you!
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Anyway, USD70 (for a pair) poorer later, they duly arrived.
Right out of the box, they look good. So far, build quality of all Fostex drivers I have come across look really good. Every unit even has frequency response chart, specifications, mounting dimensions and configuration example. Cool! I was suprised to find it quite heavy, 340g (0.75 lb) AND it says "alnico magnet". If you haven't been on this planet lately, a search on Ebay will show you that speaker drivers with alnico magnets command a stratospheric price over their non-alnico cousins. Go figure.
However, they are too big to be mounted on the current tweeter position. Those guys on the Super 12 Forum is right. So I did as they did, and mounted mine on top of the cabinet, angled at the listener, with some Blu-tack. Will fiddle around until I find a position I like.
Removed the Audax, wired the Fostex, played music and...
Wow! I haven't heard so much treble from my system! WAY TOO MUCH! I get too conscious of the treble! But it's very clear, and very extended (I don't have to say this right?). Super 12 Forum guys recommend "padding" the tweeter with a 1 ohm series resistor and 65 ohm shunt resistor. Another e-mail on the Forum recommended a single 0.6 ohm series resistor. Well? What do I have? I found some 1 ohm 1/8W resistors, so I just paralleled 3 of them (to get a higher power rating) and the treble doesn't get too obtrusive now.
Okay, the sound. I hear a wider, more open soundstage. Still can't hear much depth, but I reckon it's more of a "room" problem. Instruments have more "air" around them. Finally cymbals and hi-hats have more "body". Vocals are impressive too. Other than the "air" factor, it also seems to have more "body" and "feel" to it. Wow!
Got to agree with Michael Greene here from the Super 12 Forum:
"At Larry's suggestion, I ordered the Fostex FT17H tweeters for the Hammers and have just in the last couple of days, had a chance to hook them up. I have to say that if anything, these tweeters are under-hyped. I haven't heard much mention of how pretty they sound. This is the most unfatiguing yet extended treble I've ever heard—and that w/o much break-in. (Noting that I hate sizzle or exaggerated treble.)"
Err, wish to add another point. DAC in use now, is the non-oversampling variety, thus, there should be a 44.1kHz menace at the output (not that I could hear it). Since this Fostex has output up till 50kHz, there should be 44.1kHz flying out (assuming my output trans has such high frequency extension). Heard that some commercial mosquitoes repellant utilize a 40kHz frequency tone to "shoo-shoo" mosquitoes away. Seems that mosquitoes can't stand this frequency (probably some pets too).
So stay tuned. If I get less mosquito bites, the Fostex, together with the non-oversampling DAC, will be the audio and household BARGAIN of the century. : )