Awesome! That's exactly the kind of "education" I was hoping to get. Thank you SO MUCH for the help. I'll factor your comments into the final cabinet size, and report back once I've had a chance to build and listen to them!
Dave
No such thing as too wide a baffle, only a point of diminishing returns. 30? is normally the minimum unless near a wall or corner boundary before potentially needing any baffle step loss correction [BSC], so if practical, making the cab just deep enough for the driver plus a rear panel mounted brace/cradle to maximize baffle width ?kills two birds with one stone?.
Harry Olson?s circa 1950 tall reflex designed for a home ?high quality? sound system [later marketed as the LS-11] ?taught? me that placing vents up near the driver in a tower alignment isn?t a very efficient use of its high aspect ratio, so recommend the vent[s] be placed closer to the bottom to take advantage of the cab?s ? WL pipe action to provide some acoustic loading to them plus any mid bass notching due to floor bounce will be greatly reduced.
Anyway, the first sim is yours, the second with the vents relocated down 40? from the top and the third is a net Vb = Vas, Fb = Fs MLTL to get the driver up to the desired 42? seated ear height, so 64.5? i.d. tall, WxD = ~331.78?^2, driver down 22.5?, vents down 51.6?, though only baffle thickness [0.75?] long to get the lower tuning due to the additional TL loading.
Spikes not factored in, but an inch either way shouldn?t be audible and if you have a floating floor, the spikes may help.
Regardless, mass loading the cab to the floor is desirable as it can audibly ?tighten up? the bass line, sometimes even with cabs this large, so a large ?hanging gardens? potted plant is a potential tweak with some WAF and the foliage does a decent job of damping spurious reflections off the cab/driver.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Awesome! That's exactly the kind of "education" I was hoping to get. Thank you SO MUCH for the help. I'll factor your comments into the final cabinet size, and report back once I've had a chance to build and listen to them!
Dave
You're welcome! Looking forward to what you wind up with, thoughts on its performance once dialed in.
GM
Forgot to post Olson's 'MLTL' [bummer, it won't display large enough to read]...........
Last edited by GM; April 10th, 2013 at 08:33 PM.
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
It blows up fine on other forums, just not this one! I need to add it to Flickr.........
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
A bit OT - but, you use Photoshop, right AB?Originally Posted by Altec Best
If so, after you resize go Filter menu -> Sharpen -> Unsharp Mask and then in the dialog you can play with the three sliders to get a desired effect.
For line drawings, try something like
Ammount: 228%
Radius: 8.8 pixels
Threshold: 2 levels
But experiment.
After all the support I received here on the board, I thought I should give you an update. My local cabinet maker wanted almost $1800 for cabinets--far more than I hoped it would be. As I was wrestling with what to do, a pair of Model 19s became available in Los Angeles, which I purchased for a reasonable price and picked up myself. So now I'm loving Altec-life again! Thanks again for your support!
Dave
Great! Any pics and/or listening impressions of your 19's? How much did you pay/what is their condition/are they all original--if you don't mind me asking?
Being of "Sound" Mind
They look very nice, with no dents in the cabinet, although at least some of the veneer appears to have been replaced. The drivers are all original. The crossover is stock. The grills are in very good shape. I paid $2250.
Although I don't have my old 604-8Gs anymore to compare to, if memory serves (and it probably isn't terribly accurate) the 19s seem better balanced top to bottom. I was never very happy with how the 604s imaged, but even with the 19s up against the wall, the imaging is VERY good. I am VERY pleased with them, and glad I didn't go to the trouble and expense of having new speakers built!
Dave
Model 19s.jpg
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