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I like the 816 design as it seems to present the best of both worlds...the "forwardness/accuracy" of the front-loaded woofer, with the bass extension from the porting. (The larger 828 VOTT bass cabinets are too big for me....)
Is this a good cabinet choice for building a quality two or three way home system?
Also, what's the difference in the A, B and C models....? Should I aim for the 416 driver, or 515?
Thoughts appreciated.
Andrew
I have a pair of 816 VI and 828 cabinets, and in all honesty, the 828's not all that much larger. However, if you went with the 816, I would use a member of the 515 family, since that driver is designed for horn use.
Here's a picture for comparison...
http://www.hostboard.com/forums/hbmc...2011/02/13.jpg
Remember that the 816 isn't really going to go much below 45-50 Hz, so for gut shaking bass, you're going to need a subwoofer.
I disagree....... To me, the 816 is enough smaller to make a difference. I've got a house under 1000 square feet, Though.Quote:
Originally Posted by analog addict
As far as the 816 VI...... horrible horrible enclosure....... so if you find one make sure you send it to me for proper handling :-)
I agree...... not much down really low.Quote:
Remember that the 816 isn't really going to go much below 45-50 Hz, so for gut shaking bass, you're going to need a subwoofer.
It is my opinion . . .Quote:
Originally Posted by atilsley
All 816 cabs have the same horn flair, volume, and port tune.
They all will sound about the same . . . Here are a few specs that may help;
816A = particle board cabinet, painted Altec grey
816B = 7-ply birch plywood, painted Altec grey
816C = particle board cabinet, painted black with handles and corner protectors
816V = same as C model
816VI = vinyl wrapped particle board, light tan color
The 816VI is the best looking with dual vents for symmetry.
All 816 cabinets should be oriented as shown on the VI data sheet, not as shown on all the other data sheets. The horn flair is designed to be up-down to provide vertical control. This became abundantly clear when we measured the coverage pattern of the 816 for AcoustaCadd.
The early 515's and 416's are pretty similar for 816 application. 515-8G and newer are best for bass-horn uses. They offer instant response as good or better than a 12" direct-radiator woofer.
The 816 design is a bass-horn with horn-loading down to 200Hz. Vents (ducts) extend the low frequency to 50Hz. The low frequency response can be seen on the 9864-8A data sheet. However, as with any horn-loaded device, there is a drop of around 6 dB between 200H and 50Hz in free air. This drop is somewhat masked by half-space effect (3dB) when placed on the floor or against a wall. This improvement can be as much as 5dB when the cabinet is placed in a corner. In either case, the 816 cabinet is not going to "thump" and forcing it will cause the rear-loaded woofer to hit the baffle.
Quote:
Originally Posted by Audio_by_Goodwill
Alright, you gentlemen are going to force me to flip these things 90 degrees and see how they look/sound. I've actually been toying with using all the hardware these things came with and actually flying them for rears.Quote:
Originally Posted by whitebroncoii
However, I don't know if I have enough stout friends to help me get them up to the ceiling...:waver:
I thought that was Tolex?Quote:
Originally Posted by whitebroncoii
I wouldn't exactly call it particle board.......... in part because I hate particle board (it's cheap). I haven't looked inside mine for awhile, but I recall the particles being bigger, although not as big as OSB.Quote:
816VI = vinyl wrapped particle board, light tan color
I agree...... although, I wouldn't turn down a nice pair of single port cabinets, especially if they were plywood.Quote:
The 816VI is the best looking with dual vents for symmetry.
That's the way mine is. It take up less room and looks better, too. If I ever get a second, I plan on putting feet on them in that orientation. Stainless would be nice....... similar to those expensive JBL feet.Quote:
All 816 cabinets should be oriented as shown on the VI data sheet
I've got the hardware for my single, too. I keep thinking I should get rid of it, but I know a month later, I'll see a set sell on ebay for BIG $$$$, or I'll have a burning desire to fly my cabinet.Quote:
Originally Posted by analog addict
Have you dry walled the toy room yet?
And why between this and their parallel flat walls it's best overall in a HIFI/HT app to use truncated 825/828 cabs..........Quote:
Originally Posted by whitebroncoii
Yeah, ideally need the 50+ Hz Fs 803 drivers driven with period correct high output impedance amp to get the most out these high tuned cabs, but the 8G with a small amount of series resistance should work just as well.
GM
Yes, you busted me on that one. The 816VI is a special OSB developed by/for Electro-Voice portable music systems. It uses a heavy-duty water-resistant glue. There were a couple of Altec speakers using this special stuff; 9820-8A, 9850-8A, 932-8A, and AB series woofers are a few.Quote:
Originally Posted by Audio_by_Goodwill
I never would have guessed that it was a custom spec'd material. I kinda thought I was splitting hairs, after I replied.Quote:
Originally Posted by whitebroncoii
I wish my cabinet wasn't covered in latex paint. I'd love to cover the cabinet in veneer, or a thinner plywood. I'm a little concerned that veneer may not stick to the latex and vinyl.
By truncated, do you mean a cut down 825/828 cabinet, or do you mean the horn of the 825/828 is truncated as designed?Quote:
Originally Posted by GM
Thanks guys...I guess I'm trying to work through the trade-off of clean bass vs deep bass (without resorting to massive cabinets). I'm leaning towards clean bass...so the 45-50Hz cut-off is doable. I built a 5 meter tapped horn for another app, so I can do something similar again for the ultra LF's.
Analogue, what is the blue horn sitting on top of the 816...a Manteray? What driver?
If you were listening to a 'simple' two-way, would your 816/Manteray do it for you?
While the horn is truncated, I meant either scratch build or cut down an 825/828 cab to make a better overall performing 816. Guess we could call it an 816VII. ;)Quote:
Originally Posted by Audio_by_Goodwill
GM
Hmm, you'll get 'cleaner' bass with similar efficiency from dual drivers than a single in any of the small Altec mid-bass horns.Quote:
Originally Posted by atilsley
GM
GM, noted...but simplicity/cost also a part of the equation.
I may go back to the large ported box using the 416....but I really want to try the front loading bass.
As an aside, what's your view on having the GPA Altec 399 2-inch driver (500Hz-15,000 ) vs the 1-inch driver 902 (500Hz-20,000) to operate in the wooden 300Hz Cogent/Bill Woods 300Hz front conical horn? Sorry to annoy people with this oft asked question....but I'm trying hard to make the right decision, without making this a more complex three-way system....
Perhaps I should just go with something like the 390 (300Hz - 7,000) and make the wood horn operate the best as a lower-mid frequency horn vs 'full range.' But then I need to upgrade the xover and buy a HF horn (eg JBL 2040/Beyma copy). My thinking is, if Cogent can build a classy two-way (albeit with expensive field coil drivers), then others should...think altec Model 19...!
Andrew
Quote:
Originally Posted by atilsley
Yeah it's a MR94B Mantaray. That 816VI originally was paired with a VIT, but I just don't think even the Mancave has the room to really make the most of them.
I have listened to the MR's and the 816VI with a single order simple cap crossover, and that combo can sound quite nice. I can't remember if Pano heard that set up when he came over, but I know another one of my audio buddies, the founder/former owner of Cary Audio really liked it with a certain cap value (which currently escapes me)
I've used different drivers on the horn, such as a 288-16G and a 902-8A. So far I think the 902 has sounded the best. Also, as I've mentioned before, the 515's in the 816's are a bit of an oddball. They're 515-16G HP's.
I recently picked up some Audax PR380 N0 15" woofers, which have a 97-98 db efficiency rating. I'm tempted to try those in the 816's or 828's also.....
Bottom line is that a simple 2-way using the MR's and 816's can be made to sound very nice indeed....:2thumbsup:
What for? To make it more esthetically pleasing? I figger I can do that by hanging all my other toys on the walls, such as a few swords, pictures of scantilly clothed women, etc.Quote:
Originally Posted by Audio_by_Goodwill
Besides, dry wall would increase the acoustic reflectivity of the room, and I don't have any interest in that either....
I like the way mine sounds with the much smaller Mantaray of the 9864-8A, but I don't have the listening experience to the wide variety of Altec gear that many(you) here do. Come to think of it, I don't even have the proper crossover........ I've got one out of an M500 that cross's over too low if I recall correctly (info from Bfish).Quote:
Originally Posted by analog addict
Oh, I don't know...... maybe less pink, and less itchy if you bump up against it.Quote:
What for? To make it more esthetically pleasing?
Quote:
Originally Posted by Audio_by_Goodwill
To borrow a phrase from another one of my hobbies.
It's meant to be comforting, not comfortable....:snickerpup:
Yeah, well, you left that part out...........Quote:
Originally Posted by atilsley
My only real 'hands on' knowledge of the 1.4" exit drivers is with the 805/288B combo which I found a bit too weird sounding due to multi-cell comb filtering (at least in an in-room stereo app) and rolled off too much up high for my then youthful ears, so initially switched to 511/802 and later added a second one stacked on top to get the 'full' mids of the 805 and the extra highs of the 802 plus a better overall polar (power) response, and at the time, cheaper to boot.
Unfortunately, this isn't practical with round horns plus his don't appear to account for the narrowing up on axis that conical horns cause if the last ~1/3 of the expansion isn't flipped out like DSL's Synergy or Geddes/similar slow rollover, limiting its HF BW usefulness as a waveguide (WG) for me.
Not having experimented with this simple horn type and only having heard crude versions, I can't comment on how they sound wide band, though considering who design/makes them I assume they perform better overall than Altecs. Still, blending a round source to a rectangular one (assuming the 816) must present some acoustic discontinuities through the XO BW if sitting much off axis and I assume why Cogent's horn is either mated to another round horn or large point source in what appears to be a modest MLTL.
Does he offer any polar response measurements of this horn?
Anyway, XOing at least an octave below where it starts to narrow up seems a good choice for a simple/benign 1st 0rder XO, so the 399 would be my choice.
GM
Primarily to contain fiberglass dust, so some sort of fabric stretched over it which can add a bit more damping and esthetically pleasing too depending on what you choose.Quote:
Originally Posted by analog addict
GM
Thanks GM....
Am I loosing much by 'only' having the driver/horn run up to 15,000hz? What was the range of the Model 19, for example...?
You're welcome!
It depends on the source material and one's HF hearing response. At best, for men AFAIK, they will perceive a bit more detail/'air' around some instruments while for at least some women it's the difference between a properly tonally balanced HF harmonic structure or not. Indeed, I found that for noisy and/or sloppy recordings, at least younger women preferred a system that was pretty much done by 15 kHz, especially if listening to FM radio.
On axis and depending on where the HF adjustment is set and assuming a fresh diaphragm, the M-19 is solid to 20 kHz.
Regardless, adding a super tweeter isn't so much about getting to 20 kHz than it is about the sound quality (SQ) of the HF and controlling it over a wider 'sweet spot'. Even the 1" exit drivers are just making break-up noise off its suspension at these high frequencies with it's throat size controlling them, ergo some reflections get added to the mix since it's much too big for 20 kHz and if the mouth isn't damped enough, then between more reflective 'scatter' off it and eigenmodes reflecting back to the throat to modulate the delayed HF, there's no real SQ.
A larger diaphragm/throat then will start breaking up sooner and add more reflections to the mix, so HF SQ can only be worse, ergo EQing it flat out to 15-20 kHz isn't something I'm going to recommend unless it's coupled to a plenum loaded mega multi-cell similar to Jensen's 32 cell behemoth where there's so many close coupled super tweeter horns that we perceive it as a huge, very wide BW point source.
Anyway, as 'bowtie' noted in your other thread, there's duplex compression drivers available now to deal with this once frustrating 'juggling act' of trade-offs.
GM
GM, thanks....I like the concept of the BMS co-ax drivers for sure...but I'm trying to stay with 'Altec' (GPA) in order to promote the name/gear here in Oz....hence me agonizing over 1-inch, 2-inch format etc.
At the end of the day, I'm trying to build a system that will be well suited to average room size listening, two-way, moderate horn size and 'moderate' bass cabinet. If the 416 runs nicely to 1,000hz, then the 1-inch 902 GPA driver might just do the trick for the rest.
If I move to a three-way, then I'll go for a 2-inch driver for the 1,000-7,000 range, then tweeter etc.
Those co-ax drivers are cool, but what horn loads the driver down to below 1khz and has good qualities above 10khz? I just want to know how people think about choosing horns for something like that.Quote:
Originally Posted by GM
The fiberglass dust hasn't bothered me so far, but I have considered fabric, even some sort of plastic like Tyvek, but it this piont due to cost and time constraints, I have chosen the path of least resistance (or is it the path of least effort?) and done nothing....:cool:Quote:
Originally Posted by GM
The entire HF horn is built into the driver, so the horn is chosen no differently than if it was a wide BW driver such as a 399.Quote:
Originally Posted by Captgonzo
GM
Ok - that makes sense now. Thanks!
Nice that you want to promote Altec/Great Plains Audio in Australia/New Zealand. New 416's and 902's from GPA would work very well together if you want to keep things 2 way (as you suggested)--you could even use a cabinet with a similar volume to a Model 19. You'd want to stay away from most larger format h.f. drivers in a two way system if you want response up to 20,000 hz. I've also heard (but have not yet confirmed) that GPA is now manufacturing brand new 802-8G drivers (the drivers that were used in most Model 19's--the 902's were used toward the end of their production) and those would be a great choice as well. A 416 used with either H.F. GPA driver (with an appropriate horn)--you'd basically be making a speaker very similar to Model 19's as long as you have "good" crossovers with the necessary h.f. compensation. I think it is safe to say you'd be making some of the best sounding speakers "down under". Please keep us up to date with details and photos if you move forward with this GPA/Altec project.....Quote:
Originally Posted by atilsley
No, not Tyvek. Tyvek will allow more moisture into the wall cavity than can easily be dried through the outside wall. Either something with a very low perm rating (read vapour retarder) or nothing at all.Quote:
Originally Posted by analog addict
Already decided against it, mainly due to the fire issue. And I do have a dehumidifier set up and running automatically....Quote:
Originally Posted by Cal Weldon