1) How large of a ported cabinet do you plan to build?
15PR400 ported alignments:
3.5cuft -F3=43Hz Qb=0.7
6cuft minor bass shelf -F3 =38Hz
8-9cuft -3db bass shelf -F3= 33.5Hz
1b) How wide of a cabinet do you plan to build?
---this effects the baffle step. The Model19 was 30" wide.
2) What horn and compression driver do plan to use?
3) Amplifiers?? Solid state? Husky Tube? 3Watt Tube? Separate tweeter amp?
The tweeter crossover in post #68 uses a 3-watt SET friendly topology. The best crossover for a husky amp would be different.
gabkw
That discussion quickly switched to a 3-way (Faital 18FH500, 12FH520, HF108).
Attached WinISD plots I had for ported 15PR400 vs. box volume.
---The 8cuft bass-shelf alignment would fit the M19 cabinet.
Example crossover with RLC for Zobel and cavity resonance.
That discussion quickly switched to a 3-way (Faital 18FH500, 12FH520, HF108).
Attached WinISD plots I had for ported 15PR400 vs. box volume.
---The 8cuft bass-shelf alignment would fit the M19 cabinet.
Example crossover with RLC for Zobel and cavity resonance.
Attachments
Sorry, not trying to be rude.
I thought they sounded quite good although I did feel more development with the crossover was needed. I wanted to get the L pads out of the system and wound up padding the compression driver down with resistors. After trying numerous values, I found some that allow the speaker to sound balanced from top to bottom. I also now believe my listening space is too small for such a large two-way. The 511 horn and 802 compression driver put out an enormous amount of energy. Alas, I will not be further developing these with pressure from my wife mounting to get them out of the house. I did hone my cabinet skills building these, and plan on using what I’ve learned for my next build.Thank you all that chipped in with help and supported me.
I thought they sounded quite good although I did feel more development with the crossover was needed. I wanted to get the L pads out of the system and wound up padding the compression driver down with resistors. After trying numerous values, I found some that allow the speaker to sound balanced from top to bottom. I also now believe my listening space is too small for such a large two-way. The 511 horn and 802 compression driver put out an enormous amount of energy. Alas, I will not be further developing these with pressure from my wife mounting to get them out of the house. I did hone my cabinet skills building these, and plan on using what I’ve learned for my next build.Thank you all that chipped in with help and supported me.
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A common fallacy performance wise, but the sectoral horns do need significant shelving [CD horn EQ] and some tweaking even in large rooms and the 511 in particular needs significant terminus [mouth] and throat damping to rid them of their 'squawking'/'tinny' PA heritage.
Scope out the various FB Altec, JBL and vintage speaker groups, there seems to be a ~continuous market for the M19 of most any type, condition, so may can get a pretty decent price for your labors even in this [lack of] economy.
I found the 811 horns much easier to work with than the 511 - at least in a domestic setting. Other people (like GM) prefer the 511. Both need some EQ.
The part about the wife not wanting those giant speakers in the living room is all too familiar. My Altecs, Magnepans and various home built speakers have been chased out of the living room many times.
The part about the wife not wanting those giant speakers in the living room is all too familiar. My Altecs, Magnepans and various home built speakers have been chased out of the living room many times.
True, the 800 series 1" driver was designed for 800 Hz, so marginal for 500 Hz with its near 700 Hz Fs unless on a really large horn, though the 511 is axially large enough that when combined with its originally spec'd ~720"^2 [~24 x 30"] baffle for the A7-500 to meet the mouth area requirement it can handle its 30 W power rating at low distortion.
My core problem though is that as 'sweet' as the 803/416 and especially the 515s, are in the ~ 400 - 2 kHz BW where 'honk'/'whack'/tinny' reside, their clarity relative to a horn in this BW is just too wide a gap for my hearing, so stuck with tweaking 511s or DIY to let me choose how well damped it needs to be to sound closest to "Is it live or is it Memorex" rather than just accepting Altec's somewhat muted choice.
In their defense though, the original's of each model were much 'sharper' at the expense of power handling, so must admit that history has proven they did a pretty good job of finding an acceptable compromise overall.
My core problem though is that as 'sweet' as the 803/416 and especially the 515s, are in the ~ 400 - 2 kHz BW where 'honk'/'whack'/tinny' reside, their clarity relative to a horn in this BW is just too wide a gap for my hearing, so stuck with tweaking 511s or DIY to let me choose how well damped it needs to be to sound closest to "Is it live or is it Memorex" rather than just accepting Altec's somewhat muted choice.
In their defense though, the original's of each model were much 'sharper' at the expense of power handling, so must admit that history has proven they did a pretty good job of finding an acceptable compromise overall.