From much earlier today: RE: Altec 15 inch 3154, or 416 in open baffle - GM - High Efficiency Speaker Asylum
GM
From much earlier today: RE: Altec 15 inch 3154, or 416 in open baffle - GM - High Efficiency Speaker Asylum
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
GM - you're a damn guru. I swear I need to ready like 10 reference docs to interpret your posts. <respect>
- Mike
Only 10?! I'm slipping in my dotage.I know how you feel though, Some years ago I decided to learn as much about antenna design as I knew about acoustical stuff, so already knowing the TL, horn analogies between the two, I went straight to the advanced designer's forum and most of it might as well have been posted in Sanskrit and Greek since it was loaded with their own specialized lingo and higher math intensive; plus it was obvious that they didn't suffer fools graciously and the mods would ban anyone that was there to get free design theory info that could be found searching the beginner, etc. forums. A really tough crowd compared to the audio/HT forums.
Consequently, I didn't learn much, but ultimately the 'crew' did what I wanted to do, which was design an OTA digital TV antenna for 'problem' areas like mine, though I have no clue how it was done since they declined to publish its design details.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
He's a smart cookie alright.Originally Posted by Alien_Shore
I wish! If I was, I'd of been able to do more than just lurk for ~ a year on that forum before giving up.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
I agree that the X-max of the 416 could be a problem. You don't get much bass efficiency out of an OB (that's why they put woofers in boxes) so you have to push the cone farther. That said, I've run across a number of 416s that had a Qts of 0.4 to 0.6 and that means more of a bass bump than factory specs would indicate. But less efficient, so it's a trade off.
Another thing hard to get right is the crossover. Mating an open baffle woofer and a horn is no easy task - I speak from experience! It can be done, but won't look anything like a textbook crossover.
See attached my Selenium 15" + Altec 811 Obee. It later had wings to help the bass.
I can't understand why anyone would want to go the OB route with all its limitaions. We are trying to reach down to 20Hz, after all aren't we?
I'm not. While it "may" be nice to have flat response down to 20Hz, it isn't very practical at home. Unless you listen to a lot of pipe organ music, dubstep or action movies there isn't much content down there. In fact, in many recordings there is just noise they forgot to take out in the mastering suite. You can get down into the 30s with OB, tho it's not easy. What you gain thru the rest of the spectrum by losing the bottom octave is often well worth the trade. IMO, of course.
OG: sometimes I ask questions I guess I shouldn't ask and this may be one more time. Let me lead up to it this way. I've had HD TV over the air, OTA, for I'd say ane easy 8 years already, pretty much when they started broadcasting it, and I've always used a "normal" TV antenna with an amplifier. The only problems I've had is when weather, aka heavy overcast & rain causes the signal to drop out on only some channels sometimes because its all on the UHF band now. I'm in the shadow of a large hill but not the lowest spot in the valley, so I get a pretty fair signal considering my limitations from all the greater Boston area.
Is there really something special in having a "digital" antenna?
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And a damn generous one at that too !
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