"Crossover Design for New Project"

[GM]

Greets!

A triangle is best, then one with angled sides, but Olson's work indicates up to 10.5" regular depth was acceptable, so 12" is a bit much.

Anyway, from your drawing I take it that you're not interested in a three cab MTM?

?? Unless you make ducted ports like on the Ultraflex you can't put them on the rear and still shove it hard into the corner. Regardless, unless you need long ports to get the desired tuning (which you probably won't) there's no advantage to them other than cosmetic.

Thanks again for the thought! My BD 'gift' to me was a ~$200 repair bill to get the truck to pass emission testing. If the economy wasn't so bad, I'd sell the thing and find me a pre-1985 truck that I can diagnose myself rather than being scammed since it turns out that all that was needed was the MAF sensor being spray cleaned!

GM

[Altec Best]

[quote=GM;1830578]Greets!

A triangle is best, then one with angled sides, but Olson's work indicates up to 10.5" regular depth was acceptable, so 12" is a bit much.

The reason for the extra width on the sides was to add volume to the cabinet.I shortened to 8"

Anyway, from your drawing I take it that you're not interested in a three cab MTM?

Well I would have preferred 1 cabinet for the woofers.It's kind a hard to make a modular 3 cabinet look good without tons of work & time.Up side it won't be as heavy and will be easier to move.

?? Unless you make ducted ports like on the Ultraflex you can't put them on the rear and still shove it hard into the corner. Regardless, unless you need long ports to get the desired tuning (which you probably won't) there's no advantage to them other than cosmetic.

The most important thing is bass,I want to get the most bass I can out of the 416's as there won't be any issue with the HF.The 511/288 will provide plenty of mid horn and the EV T350 for the UHF's

Thanks again for the thought! My BD 'gift' to me was a ~$200 repair bill to get the truck to pass emission testing. If the economy wasn't so bad, I'd sell the thing and find me a pre-1985 truck that I can diagnose myself rather than being scammed since it turns out that all that was needed was the MAF sensor being spray cleaned!

Your most certainly Welcome !!! Don't feel bad my last repair was $1400

I have another question though. How,Where ??? Do I mount the T350 in this 3 cab modular design if it needs to be vertically mounted above the mid horn.Here's the new drawing rev.5

[westend9]

We used to have emissions testing in MN. They did away with it. I came in contact with a fella' that showed me how to make even the worst oilburner pass the test. Add one quart of alcohol to 1/8 tank of gas = pass test. Works for diesel, also.

I somehow was thinking the horn would be on the top of the woofer cab and the tweeter above that?

[Altec Best]

We used to have emissions testing in MN. They did away with it. I came in contact with a fella' that showed me how to make even the worst oilburner pass the test. Add one quart of alcohol to 1/8 tank of gas = pass test. Works for diesel, also.

I can't imagine that would be good for your engine as Alcohol burns extremely hot.

I somehow was thinking the horn would be on the top of the woofer cab and the tweeter above that?

That is what I wanted to do.But the guys are saying a MTM design would sound better. I don't know, this is why I'm asking questions and needing help.

[bfish]

With two woofers in close proximity playing the same material, they essentially become a single source which appears to your brain to be located directly between the two. With an MTM, that means the woofers and mids appear to come from exactly the same place (the middle), not too unlike a Duplex.

With both woofs vertically below the horn, the apparent source of the LF material (again, between the woofs) is now at least 20-24" away from the location of the mid source. That results in you hearing both sources independantly, and they won't appear to blend into a single source until you're at least 25' away from them. That's why in our semantic discussion of vertical vs horizontal, horizontal might be preferable over vertical, even if the Q is less of a match, since it puts the apparent sources closer together.

When they were used in theaters and venues where the listeners were at a distance, the relatively large scale (distance from LF to MF) of Altec systems didn't pose a problem. Put them up close in a living room though, and you can easily hear it.

For the tweets (if you must use them) you could put them at the bottom of the top woofer cab, and symmetrically to the side of the woofs to keep everything close together.

[GM]

OK, as I noted in #43, my thoughts are to make two MLTLs that ~fill up the corners from floor to ceiling along with the horn cab, so considering all the gain a corner gives us, the cabs may be big enough without the forward 'extension'.

??? Three flat baffles (which is all that's visible on the cab) is hard to make/finish?!

Well, there's (mid) bass where the 'slam'/'punch' is and what Altec alignments concentrate on, then there's the low fundamentals that if too strong will audibly modulate the lower mids, so not sure what you mean by 'getting the most bass' out of a 416 since for one reason you'll need more than one corner just to let one 416 'be all it can be' all the way down to its Fs.

All things considered, offsetting the 511 to the inside (woofers too) and mounting the ST between it and the side wall seems the best compromise. As to which way to orient it, you'll just have to try it both ways, but in theory, vertical is the best compromise.

Anyway, assuming a 96" ceiling height and an 11" H x 34" W o.d. horn cab, then with simple flat baffles there's ~12.53 ft^3 gross available for each woofer in a 42.5" H x 34" W MLTL with the woofer at the extreme top and the vent near/at the bottom; so once total system height is adjusted to ~easily slide the top cab in place, account for the driver and a bit of driver bracing, there's at least as much net Vb as an 828, ergo probably no need for any extra depth unless you shorten them a bunch.

Final tuning will need to be done in-room, but I imagine it will be fine down around Fs or at least the lowest note on a grand piano (~27 Hz). Sealed or EBS vented aligned such as mine and pipe organ symphonies isn't out of the question with room gain governing the low distortion SPL limit.

Once final dims are worked out, I'll be able to figure a range of vent sizes to try.

GM

[westend9]

I can't imagine that would be good for your engine as Alcohol burns extremely hot.

The idea is to run your tank down low, add the alcohol, enter the test site, pass test, put some more gas in the tank.

FWIW, all gasoline at the pump in MN must contain 10% alcohol. We do a lot of E-85 up here, as well, 85% alcohol.

That is what I wanted to do.But the guys are saying a MTM design would sound better. I don't know, this is why I'm asking questions and needing help.

I'd definitely follow the advice from the learned members like GM. I have ultimate respect for their views on Altec and most other things.

[Altec Best]

[quote]

With two woofers in close proximity playing the same material, they essentially become a single source which appears to your brain to be located directly between the two. With an MTM, that means the woofers and mids appear to come from exactly the same place (the middle), not too unlike a Duplex.

I gotcha now, Understood in a living room environment a over under con-fig.with the horn on top, would be too close for proper sound.

With both woofs vertically below the horn, the apparent source of the LF material (again, between the woofs) is now at least 20-24" away from the location of the mid source. That results in you hearing both sources independently, and they won't appear to blend into a single source until you're at least 25' away from them. That's why in our semantic discussion of vertical vs horizontal, horizontal might be preferable over vertical, even if the Q is less of a match, since it puts the apparent sources closer together.

I wish I had the room to mount them horizontal,but with 19's, Cornwalls,612's,etc.. space is now limited But if all works out with this pair the Cornwalls will be up for sale.

For the tweets (if you must use them) you could put them at the bottom of the top woofer cab, and symmetrically to the side of the woofs to keep everything close together.

I would really like to as the 288's drop like a rock at 15 khz and listening side by side with my 19's you can hear the difference.The snare drum,crash cymbals are not as pronounced.And they are part of music that I really like.Let me see if I can describe this: Without the tweeter it sounds like you know when a drummer hits a cymbal and then will grab it to stop it from vibrating,well that's what it kinda sounds like to me without the tweeters.With the tweets the crash cymbals seem to hang in the air so to speak. I don't know if that was a good description but that is how I hear it.I dunno

[quote]

OK, as I noted in #43, my thoughts are to make two MLTLs that ~fill up the corners from floor to ceiling along with the horn cab, so considering all the gain a corner gives us, the cabs may be big enough without the forward 'extension'.

I thought cab was going to be 60" max

Well, there's (mid) bass where the 'slam'/'punch' is and what Altec alignments concentrate on, then there's the low fundamentals that if too strong will audibly modulate the lower mids, so not sure what you mean by 'getting the most bass' out of a 416 since for one reason you'll need more than one corner just to let one 416 'be all it can be' all the way down to its Fs.

What I meant was I just want the cabinet to have enough volume for the 416 to produce enough clean deep bass.

All things considered, offsetting the 511 to the inside (woofers too) and mounting the ST between it and the side wall seems the best compromise. As to which way to orient it, you'll just have to try it both ways, but in theory, vertical is the best compromise.

I was thinking of what Brad said to mount it in the top cabinet just above the 511 and just below the top 416 or close to the side of 416 in top cab.

Anyway, assuming a 96" ceiling height and an 11" H x 34" W o.d. horn cab, then with simple flat baffles there's ~12.53 ft^3 gross available for each woofer in a 42.5" H x 34" W MLTL with the woofer at the extreme top and the vent near/at the bottom; so once total system height is adjusted to ~easily slide the top cab in place, account for the driver and a bit of driver bracing, there's at least as much net Vb as an 828, ergo probably no need for any extra depth unless you shorten them a bunch.

This is where I don't understand.I thought we are going with a cabinet of max height 60".I think I would have a hard time getting this one passed my wife.She's pretty cool about things but this one I'd be worried about.Or I'll be using that ply to build a doghouse that I'd be calling home. It would have a kick-ass sound system though.Just run out some power there honey.

Final tuning will need to be done in-room, but I imagine it will be fine down around Fs or at least the lowest note on a grand piano (~27 Hz). Sealed or EBS vented aligned such as mine and pipe organ symphonies isn't out of the question with room gain governing the low distortion SPL limit.

Once final dims are worked out, I'll be able to figure a range of vent sizes to try.

GM

Cool this is definitely where I could use some help as well.

[quote]

The idea is to run your tank down low, add the alcohol, enter the test site, pass test, put some more gas in the tank.

I got ya now yes they use as a seasonal fuel.The fuel with a higher alcohol level is the summertime formulation I'm pretty sure (For Ozone).

I'd definitely follow the advice from the learned members like GM. I have ultimate respect for their views on Altec and most other things.

Agreed !! That is why I asked for their help.GM,Brad,Pano,Steve Mac, all guys who's expertise I value to a very high degree and I wouldn't be able to do this build without their advise and guidance.Sometimes I have a hard time following their instruction as they are so far advanced in this field than I.So I would like to say, Thank You So Much guys for your assistance it is greatly appreciated. As they are volunteers, I hope I can pay them back with building a top-notch speaker that would make them Proud.... Again Thank You So Much!!! :thankU: Kind Regards ~ John

[GM]

Don't feel bad my last repair was $1400

Bummer. Everything is relative of course, when I totaled it up it came to right at $228 which in my current budget equates to ~5.18 months of gas or ~2.28 months worth of groceries. Hopefully, $1400 didn't take such a big chunk out of yours.

I came in contact with a fella' that showed me how to make even the worst oilburner pass the test. Add one quart of alcohol to 1/8 tank of gas = pass test. Works for diesel, also.

Unfortunately, this won't help a 2000 or newer ODBII equipped vehicle AFAIK since you won't be able to successfully complete its drive cycle required to reset the computer/clear out any DTCs.

GM

[Old Guy]

I can't imagine that would be good for your engine as Alcohol burns extremely hot.

Not quite. Alcohol has about half the BTU content of gasoline...18,400 BTU/lb/9,500 BTU/lb

And many older cars have been successfully run on up to 40% mixes...methanol is corrosive to injector parts. That was a serious issue...


Alcohol is WAY more expensive though...your tax money subsidizes ethanol in order to make it cheap to use...

But in small amounts, alcohol is a good octane improver. "flex fuel" vehicles automatically adjust to the fuel mix...
I support cellulosic alcohol, but most of the subsidies are going to overpriced corn, rather than using biomass.