GM Thanks!... I measured my old holes when i took out the horn last night center line of hole was 4 3/16 in the front ,can't remember the back ones by driver now, I will just do as u said and measure back 19.3 and use that as a guide then go from there. So just drill new holes right in the top of the bass horn and use t-nuts? I also do not have access to any electronic type devices so can't use a delay etc to set these up. When u say wire out of phase Do I keep it that way also? Above u said to wire it out then mount horn and switch leads just wondering? When U mean sled what exactly u talking about? I was going to mount the wings to the cab using a 2x4 gasketed to the side and attached to wing brace and then drill a hole thru it and use some ready rod on top and bottom going to each wing to hold it to cab, that way their removable and would be very secure also.The horn deal maybe I will have to build a double wall up there to mount to the front baffle board to keep everything in alignment? One other thing my vent was 18.25x 2.5 what will its size need to be now when it is 28.5 wide to keep it tuned where I had it?
Last edited:
Hi Pano,
Do you mean 9 inches netween the front of the 825 and the front bracket supporting the 1505B?
Ok here is a pic of how far back the horn will be with the proper 19.3 spec seems awful far back from the front of cab doesn't? It is 7" to front of cab from edge of block. FWIW it wasn't aligned when it was inside cab like you thought GM!... I think I will just build side wings otherwise I don't know how to make that horn mount work and sound right and keep the VC aligned
Attachments
That's just a starting point for finding the correct setback and since it's an 811, I imagine it will move forward somewhat, but not having timed one I don't know how much.
Anyway, as I noted, the easy way is to mount it to the top 'wings' and use digital time delay (TD). If you don't want to go this route, then from a sound quality (SQ) point-of-view (POV), better overall IME to properly align the horn and skip the top 'wings' since you're already getting good room loading down low.
That said, Altec would sometimes use a cab width horn baffle, so that's one option and I see no reason why the full size top 'wings' can't be used complete with connecting shelves if you want to go to the extra effort, though even if it's just a horn perched on top, any horizontal surface in front of the horn ideally needs damping to attenuate early HF reflections.
Long term though, switching to a 511 or some other much longer horn seems a good plan for full 'wings'.
GM
Anyway, as I noted, the easy way is to mount it to the top 'wings' and use digital time delay (TD). If you don't want to go this route, then from a sound quality (SQ) point-of-view (POV), better overall IME to properly align the horn and skip the top 'wings' since you're already getting good room loading down low.
That said, Altec would sometimes use a cab width horn baffle, so that's one option and I see no reason why the full size top 'wings' can't be used complete with connecting shelves if you want to go to the extra effort, though even if it's just a horn perched on top, any horizontal surface in front of the horn ideally needs damping to attenuate early HF reflections.
Long term though, switching to a 511 or some other much longer horn seems a good plan for full 'wings'.
GM
Attachments
Yea It Looks like when they were mounted inside it was about 16.25 or so to VC, maybe i will just go and match that on top and call it good? Here's is a pic of my new bottom baffle plate and port. The port is 10x 2.28,will test it tomorrow for loudness as its getting late and kids are trying to sleep,lol.. but it sounds pretty damn good on the bottom end! Had A friend of mine use bass box pro 6.0 to get me the port size by seeing how the curve looked using the woofer in a 11.47 cab, Figured a little bigger with horn out of cab now, and it looks pretty damn sweet!.. I will see if i can get him to send me that curve.
Attachments
Last edited:
23744 diaphragm receipt that won't display properly on the Altec Forum
23744 diaphragm receipt that won't display properly on this Altec Forum response: Difference Between 806 and 802 Drivers - Hostboard
GM
23744 diaphragm receipt that won't display properly on this Altec Forum response: Difference Between 806 and 802 Drivers - Hostboard
GM
Yeah, if you're not going to do acoustic measurements, then stick with the 4-3/16" stock mounting setback.
I thought we 'agreed' to put the vent down at the bottom to at least get the max available vent efficiency/floor boundary gain. Hmm, I see casters though, so probably doesn't matter.
Looks like a ~32 Hz tuning..........
GM
En effet, oui. But that was with the Westex driver and Hiraga's crossover. But I find that works pretty well for me with the 288 driver and the 1005 horn. It's a phase alignment thing.
So the mounting tabs are about 9" or 22cm from the front of the cabinet. This should be adjusted to your horns and your crossover.
Yea We did on the vent, but i cut these at work and I have a 2x2 at the very bottom to help with bracing that part of the cab, and i have heard to always keep a vent away from any blocks bracing etc. I will see how it sounds not like i can't make a new one
.Yea if i had the tools to do it I sure would. How much is the stuff your talking about to get the proper phasing?. Here is the curveAttachments
True if you take its near boundary conditions into account when designing the vent. For instance, a shelf vent where the sides, bottom of the cab are vent 'walls' will be much shorter for a given tuning than if a cutout with the same area (CSA or Av) is well away from them.
Don't keep up with pricing, but there's a number of RTA or similar freeware computer programs and a cheap mic is all that's needed to find a deep notch in the speaker's response.
If you run a pure tone, then you will need to have 1 Hz adjustability to find the deepest notch and why a RTA with its pink noise was the traditional choice, so probably too tedious/time consuming in the scheme of things since factory XOs are rarely exactly what they claim to be due to a variety of reasons.
FWIW, the inventor/manufacturer Tom Danley recommends ARTA: High Efficiency Speaker Asylum - RE: Altec 9844As and N-800-F (1,600 Hz +6dB Peak) - tomservo - January 18, 2011 at 07:34:55
ARTA Home
GM
Well their completed for now!, I turned them on when i got done and they sounded so tinny and loud etc, so I decided to slowly move the horn up towards the front and sure enough they came right back!,, the block is 3 3/4 away from the edge of cab, very close to where they were originally inside! so not sure how that 19.3 works cause it sounded like **** lining VC's up.. maybe if the horn was longer so it came to the front and still lined up then maybe huh? They rock man! The altec one I can turn up probably three clicks more on volume than the beyma one it starts popping,lol... it should be pretty intense next week when i get the other one back from GPA! For now the horns are just sitting with a 10 lb weight on them not mounted yet, But there is no resonance moving them at all! I also did the nickle test at power and it never tipped over! I would say cabs are pretty solid! I can feel them 20 feet away on my body and I don't even have the other 416 yet! Can't even imagine how they will be with wings yet!
Attachments
Last edited:
Hmm, something's not kosher, I've done alignments many times and never experienced this plus I've been told by someone who should know that the A7-800 factory offset used over the decades is technically incorrect, but never having had any interest in these I didn't bother to note the various correct VC offsets for the different XOs at the time.
Regardless, mass quantities of music/PA has been recorded, enjoyed with much praise and few complaints, so the ideal may not make all that much difference, but it does on the 500 Hz and lower XOs and higher up for folks sensitive to timing errors, ergo not to be disregarded as a waste of time for at least some apps.
Right, if you can balance a coin on edge without it falling over or 'walking' around while reproducing LF signals down around/at Fb at the highest SPL likely to be used, then you're 'golden'.
GM
Regardless, mass quantities of music/PA has been recorded, enjoyed with much praise and few complaints, so the ideal may not make all that much difference, but it does on the 500 Hz and lower XOs and higher up for folks sensitive to timing errors, ergo not to be disregarded as a waste of time for at least some apps.
Right, if you can balance a coin on edge without it falling over or 'walking' around while reproducing LF signals down around/at Fb at the highest SPL likely to be used, then you're 'golden'.
GM
Dear all,
I need a small advice. I just did impendance mesurement with LIMP on my 825 equipped with 515-8G and and have noticed (see attachement) strange irregularities from 70 Hz and above. Someone told me that this should come from cabinet resonances... Could this be because my Tascam 122L was placed on the cabinet itself? (interferences...)
I need a small advice. I just did impendance mesurement with LIMP on my 825 equipped with 515-8G and and have noticed (see attachement) strange irregularities from 70 Hz and above. Someone told me that this should come from cabinet resonances... Could this be because my Tascam 122L was placed on the cabinet itself? (interferences...)
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
Yea I dunno either.. All I know with them sitting back that far it was like the horn was all by itself no mix with the bass horn at all etc, i just left the song playing and slowly pulled it toward me and i could hear the difference the closer i got it to the front, pretty much where they were on the other side of the cab, maybe a tad farther back 3/4" maybe is all?.. either way they sound great! Should have the other 416 back this week so then it will be rattle city ...
...
Hey GM, I think i found the issue it is a Flickr problem,I suggest using photobucket instead !!!
I was toying with your scan on both sites and encountered the same thing Flickr is the Culprit but don't know why ! When you save pics they are Copyrighted,maybe check to see if you enabled sharing in the Flickr control panel. Don't know what else to try.
Last edited by a moderator:
Greets!
This cab is a 6th order alignment, so will have three distinct impedance peaks and since the front chamber and its 'vent' has been morphed into a horn it will have a highly damped upper peak as shown around 332 Hz (if I calculated it correctly) and since the horn is too short and terminating into too small a mouth (~110 Hz horn segment 'sliced' out of a ~55 Hz horn) it will have ripples in its frequency, acoustic and impedance responses.
Don't have a clue whether or not setting the Tascam on top has any impact on its response, you will have to try isolating to see if it makes any difference, but from memory it looks like an accurate enough measurement to me.
GM
Dunno, maybe someone else with an A7-8 and RTA or similar has, or will do, the test and chime in.
Just so I'm clear though, how far back from the front of the cab is the 811 driver's (806?) VC vertical center-line?
GM
Last edited: