I don't want to hijack the thread, but just curious about the AE TD15M woofers. What does the Apollo option do, and is it worth the extra 150$ per woofer?
I see where they say it helps cool the VC, but I did not see an in depth explanation. Just curious if it is worth the extra cash.
Just ordered GPA 416-16B Alnico woofers. Will probably have them in about 9 days.
Very cool. Looking forward to hearing your impressions.
Start a thread asking about them at AK. Several members have completed builds using them with excellent results. Some fellas have even ordered sets of extra phase plugs from John to use as cabinet feet/spikes, makes for an interesting touch of cosmetic class. Dennis had his copper plated and polished, very rich looking touch.Originally Posted by Elitopus1
Not all vegetables make good leaders.
Bowtie's suggestion of the AE TD15M is a good one and certainly a viable option. Although I can't speak from first-hand experience, there's no question that the TD15M is one of the great 15'" drivers available today as they're almost universally praised.
However, there's one person that has had extensive experience with both the TD15M and the GPA 416B. In the megathread "beyond the Ariel" over at diyaudio, Gary Dahl compared both these drivers and his preference was for the 416B. The TD15 was in his system for three years prior to him switching to the GPA driver. Also, for whatever it's worth, Gary is a choir conductor and a Tympani player.
Here are some of his comments:
Beyond the Ariel - Page 1097 - diyAudio
Beyond the Ariel - Page 1105 - diyAudio
Beyond the Ariel - Page 1106 - diyAudio
Of course the above is one man's opinion and the TD15 could very well be the one preferred in a different system or by a listener with different priorities and/or tastes. However, for me, It's the last sentence in the third link I posted above that is the clincher:
"Would you say that the 416 Alnico has that larger-than-life 'Technicolor' sound they are so famous for?"
GD Response: "Yes."
To the OP: Since you don't seem to be hung up on the old Altec drivers (and rightly so IMO), then I think you'd be doing yourself a favor by getting a pair of the GPA 416-16B drivers.
I just finished reading the long thread on AK about the TD15M builds. Unfortunately, all the pics are gone. I started a new thread about AE users and their setups.
I was also curious about GPA woofer prices, since the 416B were so reasonable. I asked Bill about his 515C drivers, and he came back with a price of 550$ each. Still not bad when you look at how much original 515C cost, and the benefits of having woofers with all new parts.
Well this thread has led us/me to the real question. Along the path of trying to get these going in an acceptable fashion, I asked myself: why not pop the extra bucks and get the GPA 515-16C (that's the Alnico/Classic, right?)? That led to issue: is it a good fit with the current horn setup I have? But the real question for me is: what's the best sounding driver (and eventually, driver set) for an 828?- and that I should start on the path of discovering that. I worry that the answer is a "vintage". I am commited to owning sooner or later an optimum A7 set. But what are my target components? Other than some indications of hefty prices on vintage 515 variants, there's not too much of a financial barrier to a commited bachelor with building and repair skills- and some credit cards that are still on their feet. As far as the cabinet goes, to me the answer at this point is relatively clear: 828 in plywood. The drivers? That's where gets hairy- mostly in the woofer considerations. I'm very impressed with these horns at this point just the way they are. Some talk of how "back in the day" when the company was in it's prime, there was a bit of magic that's hard to reproduce now. I would love some feed back from anyone who has experience with the GPA 416B or GPA 515C Alnicos. GPA will be putting my 416-16B set together- I don't think he would mind if I switched the order up to the 515-16Cs.
You guys are a lot further down this path than I am. So, if you have a moment: for you guys that think you have some woofers you feel are optimum- or close to optimum, what are they?
For those who are working towards getting some woofers you feel would be optimum, what is your target?
Thanks, Kip.......
BTW, the horns are sounding so good with the Russiam MBG PIOs in the XOs, I put some FT-3 teflon 0.1uF 630V Russian coupling caps in my 300B monoblock amps. Not even broken in, they were a huge improvement- and really starting to romp now. Never knew how much of a difference these could make. Why did I wait so long to try this? Much thanks to forums for these tips........
Obviously there are some trade offs with either the 416 or 515 in a 828 cab. IMO, the 416 matches better with a small format driver, and the 515 with a large format driver. Of course this is how Altec did it (with a few exceptions including the 604).
I have run my 828 cabs with small format drivers, and a varity of horns and woofers. My favorite setup was a 416-8A woofer and a 802D HF driver on an Emilar EH800 horn. All crossed at 800hz.
Recently I bought some multicell horns (805B), and now I don't think I can go back to a 1? driver on my 828 setup. The mids are just so sweet with the 288 driver.
So now I am looking for some 515 to finish the A5 project. I have some JBL 2242 subs to fill out the bottom end for the 515.
My personal opinion, is if you are going to stay with a 1? HF driver, the 416B (the best 416 IMO), is a good way to go.
I?m sure others will chime in with their experiences also
I'm not sure there is a "best", if you're willing to tweak and tinker you can make a 421 sound damn good in an 828.
Altec built plenty of small VOT's using 515 and small format on top. The 515's extra couple db of sensitivity over the 416 is barely audible, you'll still have to pad 10db out of any large format horn/driver combo to balance the system. The biggest disparity with running small format over 515 is power handling of the HF section, hardly a matter of concern for those running single digit output power.
515 has a significantly more powerful motor compared to 416. In the same alignment the 515 will have less LFE, and of course it's midrange trumps the 416's which is a feat not many woofers can pull off.
There will be just as many rewards from optimizing the 828 precisely for whichever woofer you settle on as there will be in choosing the "perfect" woofer. Different woofers will require different tunings to massage the last bits of goodness out of them.
Further, the base 828 design has lots of room for improvement in terms of bracing, damping, mass loading, internal volume reduction, etc..
Small format VOT is a fun and exciting road to travel, there are many interesting stops along the way with something of keen interest for just about everybody. There are so many variations and possible combinations that one can enjoy the journey for a long time without boredom or repetition.
My personal thoughts on the 416.................... perhaps the best woofer ever made in a few regards. It is versatile, and can be at home in a wide variety of alignments. It can be a horn driver as well as a subwoofer. It can handle midrange duty up to 1200hz and beyond and still retain a respectable polar response. It has the sensitivity, and smooth impedance curve to allow for minimally reactive, and resistive passive crossover networks which are very appealing to the low power crowd. Most of all they are not scarce, they are serviceable, and in most cases they are pretty affordable. Although, my jury is still way out there at 750 for a new pair versus patience and thrift which can put a freshly rebuilt pair in your hands for a little more than half that. The rebuilt pair are correct Altec kit for a proper restoration, whereas the GPA is aftermarket as much as some will refuse to accept that fact.
Not all vegetables make good leaders.
I would hope the GPA 416B uses the same cone kit that GPA uses in their normal recones right? I haven't been around a pair of their new woofers to comment.
Just curious what 2-way systems Altec ran the 515 and a 1? driver together (besides the 604). I could think of a few 3-way systems, but not 2-way. Help me be more edjamacated for next time
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