model 19 clone box for my A7 500Hz components?

[GM]

416A specs ?? N-801-8A specs ??

Typo no one noticed!

16.9943 N/A BL

416A specs ?? N-801-8A specs ??

GM

[kipduff]

843 might work

http://www.lansingheritage.org/image...ure/page11.jpg

The 843 drawings show three setups for a 7.2 cu ft box using various drivers in a 24w X 38h x 17d cab- version C is for 15" driver- it's also known as an 855A furniture cab. In a 1965 brochure, the 855A is recommended for 604 types. The 855A is only 0.4 cu ft larger than the 612. That brochure shows the 856A furniture cab as the recommended cab for the Altec 416- that cab is 12.4 cu ft, which is too large for my small room- but is apparently the optimum volume. I WOULD like to use something like a 612 or 855- and might work in my small room considering the success of the open baffles with my 604-8H's placed close together at about a 20 degree angle to wall near corner.

I also discovered that the Altec 803B LF driver has identical specs and dimensions as the 416A. The original Altec data sheets for those speakers list the 612 cab as one of the recommended cabs. Of course, I'm already behind in LF SPL with these smallish boxes when compared to the loaded horns of the A7's these kits were originally in.

But then, what about a Karlson K15? Higher LF output from a small box- place the horn on top. Found good info at Jeff Markwart's Sound Practices article that the 416A is compatible ( https://greatplainsaudio.com/wp-cont...07/spaltec.pdf ). K15 would need some mods- some of which I haven't figured out yet. I have heard some info that Karlsons not good in small rooms.

Found these 416A T-S parameters in one of GM's 2006 posts : Xmax: 0.14 Re: 12.5 Fs: 21.4 Vas: 36.8 Qts: 0.27213 Qms: 4 Qes: 0.292 diameter: 12.7

Wanna get these things up and running- 612 looks like possibility. Was planning to build some for my 604-8H's anyway. Any thought appreciated. Thanks, Kip.......

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Typo no one noticed!

16.9943 N/A BL

416A specs ?? N-801-8A specs ??

GM

Thanks for this link!!!

[GM]

Thinking 612 cab size.... 6 - 9 cu.ft. (think I'm gonna do 612 for my 604-8H's) As far as height/ear level, I use heavy cinder blocks-

I have never heard of Bl or Le. They don't seem that credible to me

I have not found any specs yet for the N-500-E XO.

Xmax: 15mm

Le: 2.5

Xmax: 15mm.........s/b 1.52 mm

Le: 2.5..........All the 803, 416, 515 series Altec driver measurements I've seen, done, had a ~1.2-1.4 Le, so doubt the 2.5 spec.

OK, then better to make the cab taller to maximize net Vb for both drivers and skip the concrete blocks as this driver ideally wants a ~725 L cab and the 604 tuned to Fs based on its compliance [Vas] isn't much smaller. Since you're looking at the 612, I take it that 25.5" W x 20" D [o.d.] is acceptable and since the horn will be on top, locating the woofer at ~ear-chest height with the horn angled down is a good plan [ear height is what I currently have BTW], especially since it's a small room.

BL: Driver TS Parameters: BL (Motor Strength) >> www.speakerwizard.co.uk

Le: Driver TS Parameters: Re (DC Resistance) & Le (Voice Coil Inductance) >> www.speakerwizard.co.uk

Google Images is your friend . N-500-E: altec N-500-E - Google Search

GM

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But then, what about a Karlson K15? Higher LF output from a small box- place the horn on top. Found good info at Jeff Markwart's Sound Practices article that the 416A is compatible ( https://greatplainsaudio.com/wp-cont...07/spaltec.pdf ). K15 would need some mods- some of which I haven't figured out yet. I have heard some info that Karlsons not good in small rooms.

Thanks for this link!!!

You're welcome!

The K15 was actually designed for the 604B and similar coaxes, though only has higher mid-bass, lower mids, but less actual bass than an optimized reflex. The 803B/416A, not so much without mods.

Yeah, the K15 was designed for mono and/or wide rooms as they have > 140 deg horizontal dispersion, so in stereo better to have them angled in corners and even then it needs to be fairly widely spaced. The best option is to locate your system on the diagonal and have the Ks on the side walls; this way the complex first reflection soundfield is behind your ears where it belongs.

GM

[kipduff]

GM..

Switched gears again. Saw ad in Craigslist for decent looking 828 cabs in Modesto. In my haste to get a box for these, decided to get them ($500/pair). Made 700 mile round-trip to Modesto on Tuesday! They're pretty stock, 5/8" "particle" board, full width woofer baffle, no rails on back. Unfortunately, he wanted black to match his AV room setup, so he painted them a dark grey. Still has the original "spatter" texture- just thin dark grey coat over top. Actually in very good condition- the removable port area adjuster panel is missing so I'm gonna make stock sized one out of 5/8" MDF with t-nuts and try that out for starters.. I will post pictures when I get a chance to take some. Because at this point, I don't have the type of XO that was in this 828, I'm fabricating a custom recessed panel at back for new speaker inputs and mounting of the 1966 internlly mounted 500 Hz XO's- both will be below the rear surface. Hope to have them running tomorrow!
Three questions:

1) woofer terminal connectors are numbered 1 and 2- seems #1 is positive- someone or factory wrote a "+" sign below it. Do you know if that's correct?
2) tweeter connectors are not identified- but under the cap, the left side connector is hooked to "L1"- is that Altec terminoligy for "+" pole?
3) is horn wiring supposed to be connected reverse polarity in this case?

I gonna follow your recommendations that I saw in another post about keeping voice-coils of upper and lower drivers on the same vertical line.

Thanks for your suggestions, Kip.........

[kipduff]

GM..

Switched gears again. Saw ad in Craigslist for decent looking 828 cabs in Modesto. In my haste to get a box for these, decided to get them ($500/pair). Made 700 mile round-trip to Modesto on Tuesday! They're pretty stock, 5/8" "particle" board, full width woofer baffle, no rails on back. Unfortunately, he wanted black to match his AV room setup, so he painted them a dark grey. Still has the original "spatter" texture- just thin dark grey coat over top. Actually in very good condition- the removable port area adjuster panel is missing so I'm gonna make stock sized one out of 5/8" MDF with t-nuts and try that out for starters.. I will post pictures when I get a chance to take some. Because at this point, I don't have the type of XO that was in this 828, I'm fabricating a custom recessed panel at back for new speaker inputs and mounting of the 1966 internlly mounted 500 Hz XO's- both will be below the rear surface. Hope to have them running tomorrow!
Three questions:

1) woofer terminal connectors are numbered 1 and 2- seems #1 is positive- someone or factory wrote a "+" sign below it. Do you know if that's correct?
2) tweeter connectors are not identified- but under the cap, the left side connector is hooked to "L1"- is that Altec terminoligy for "+" pole?
3) is horn wiring supposed to be connected reverse polarity in this case?

I gonna follow your recommendations that I saw in another post about keeping voice-coils of upper and lower drivers on the same vertical line.

Thanks for your suggestions, Kip.........

Well I found answers re-reading the yellow label on the original XO- it says reverse polarity- Markwarts article says not. I'll worry about that later.

THese old XOs are acting like they're old and worn out- not odd considering they're 51 years old! No HF out of either- and one woofer sounds horrrible/garbled with low db. Opened them up- components are burried in thick tar. Have seen online where someone did refurbish a set of these- so I guess tar can be removed. Am considering rebuilding these with new caps and am open to any suggestions. This would not necessarily be last setup- just curious to hear the 500Hz XO sound- the Markwart A7 set up was using same/similar components. Not sure if there any Altec later type drop-in XOs for me because they all seem to be 8 Ohm- mine are 16 Ohm drivers.

[Elitopus1]

If you are going to build crossovers, I would consider a design with some MF shelving. Something like the Hiraga xover is closer to 500hz. And it will work for a small format driver too.

Or just reuse your crossovers with new coils and caps of the same values.

Have you run a freq sweep of each driver (not connected to the crossover) to make sure they are all healthy?

[kipduff]

If you are going to build crossovers, I would consider a design with some MF shelving. Something like the Hiraga xover is closer to 500hz. And it will work for a small format driver too.

Or just reuse your crossovers with new coils and caps of the same values.

Have you run a freq sweep of each driver (not connected to the crossover) to make sure they are all healthy?

I've done a sweep on one kit- seemed fine. The other kit is in the cabinet right now- will check it soon.

At this point, going to reuse the XO with new caps. I will respond to your post on the other thread....

[gdmoore28]

Hi Kiduff -

Been following along with your progress. How about some pics of what you are working with? I know, I know - if you've seen one . . . but photos sort of personalize the experience for us.

Keep us updated!

GeeDeeEmm

[kipduff]

Hi Kiduff -

Been following along with your progress. How about some pics of what you are working with? I know, I know - if you've seen one . . . but photos sort of personalize the experience for us.

Keep us updated!

GeeDeeEmm

Yes. Absolutely want to show them off. As you know, posting photos here is tricky. Some one suggested DropBox- so I will do the leg work and start posting. People will have suggestions and knowledge about these speakers that I don't have. Also, between job and wanting to get these going, photo posting went to the back burner. I'll start now with DropBox- any other suggestions for posting photos?

Also, glad to hear from you. Since I have to rebuild the XOs (both messed up), I thought of your post on the other thread. I am going to do a quick refurb at original 500Hz of the XO with Russian PIO caps which are on their way. Was able to put together exact cap value sets thru a guy on eBay in Bulgaria. Tar-embedded resistors and inductors will stay for now. Consensus seems that higher XO frequency is preferred. So after listening to these with refurbed stock XO, I will consider next steps for XO. I need to review your thread and project. Today, among other things, I am raising and wall mounting my 55" Samsung 4k TV to make floor space for the A7s! LONG LIVE THE BATCHELOR CAVE- no WAF issues here! Actually gonna be pretty comical. Every post I found about "A7's fine for small rooms" are etched in my mind......

[GM]

Three questions:

1) woofer terminal connectors are numbered 1 and 2- seems #1 is positive- someone or factory wrote a "+" sign below it. Do you know if that's correct?
2) tweeter connectors are not identified- but under the cap, the left side connector is hooked to "L1"- is that Altec terminoligy for "+" pole?
3) is horn wiring supposed to be connected reverse polarity in this case?

I gonna follow your recommendations that I saw in another post about keeping voice-coils of upper and lower drivers on the same vertical line.

Thanks for your suggestions, Kip.........

http://www.lansingheritage.org/image...ign/page15.jpg


http://www.lansingheritage.org/image...ign/page16.jpg

Regardless, I've learned the hard way never to trust polarity markings because in my then teen youth I thought the Altec distr. was 'jerking my chain' about never trusting them, so long since been ignoring them, using a battery or impulse test to find which terminal attached to 'battery +' blows a piece of toilet paper or similar forward/away from the driver face [compression stroke in acoustic speak, rarefaction stroke on intake] as opposed to the diaphragm's relationship to the motor and mark it 'positive' or '+' with something that will stand out at a glance. Ditto anything polarity centric if you have to use any sort of magnifying glass to see tiny markings and/or didn't pay attention when replacing them .


As you can see, Altec's way can be quite confusing, especially as to when to reverse polarity; better to understand the basics, i.e. for each XO slope order there's a 90 deg phase shift [lag], so with a 2nd order the HF is lagging behind 180 deg out of electrical phase, but if you reverse the HF's polarity, it's now in phase, though still lagging in time by however many milliseconds [ms] of the XO frequency [~SoS/(4/slope order)/XO frequency].


Note that all of this for HIFI/HT is kind of bogus due to small room acoustics and other variables like the acoustic center of a compression driver rests on its phase plug and moves forwards/backwards with frequency on a point source, so only accurate at one frequency; plus a point source starts with a 90 deg phase lag relative to a compression driver, so either the acoustic centers need to be gapped an extra 90 deg relative to a compression driver or use a 3/2 slope order XO.


Historically then, the typical DIYer tried swapping polarity of a speaker's HF [mids, then HF to mids for three way] and whichever one sounded best was the right one regardless of markings, theory.


Explanation of Time Aligned and Linear-Phase? - diyAudio


You're welcome!

GM