Subs needed for home theater

[bigjunglejim]

Hi all.. this is my first time here.... I'm setting up a home theater system... I have 5 Altec model 19's... I was using two Altec 3184's, each in a 12 cu ft Altec enclosure that used walnut veneer MDF with bases and grill cloths (including the Altec name badge on the grill) to match my model 19's. A VP at Altec gave special permission for these cabinets to be custom made for me by their cabinet makers (Web Massey in Orange County). These speakers produce great low end but, they aren't fast enough. The manager of Stanal Sound (Stan Miller's sound company *in the 1980's) loaned me a JBL system that was much faster than my 3184... I did a A-B comparison and I was very disappointed in the Altec units..... I'm now looking for an appropriate sub system. Any suggestions? By the way, I have a considerable inventory of Altec 416A's, 416B's, 515B's, 421, 421-LF and 12 604's. Please respond to me directly as I don't read Hostboard often... Thanks... Jungle Jim [email protected]

[Old Guy]

Sorry but I don't email very often. You'll just have to fing the time to read the board. It kinda violates the spirit of the board to ask for email replies. With public posts everyone benefits...

I would suggest doing a google for Tuba subs. The T36 has usable response to 15 hz. You will need at least 2 of them to get that. The problem is going to be many Altec drivers are not suitable. In the old days with horns that were 80 hx cutoff and bass reflex below that needed a very low resonance driver. In a lower horn, the horn loading actually lowers the resonance of the driver, often to about half. So a driver with a higher resonance to begin with is needed. I haven't really looked at the parameters of the 421 to see if it would work. The 515G may work, it has the motor strength but other specs are out of line. Something like a 421 with a Kevlar cone and the 515G's motor would be a lot better. Horn loading gives great transient response, which I assume is what you men by "slow". A smaller cone helps too.

Beyma LX60 15" may do the job.

To be accurate, you will need a crossover with delay capabilities. The long horn path (9 feet or so) delays the LF energy. To restore this you"ll need to delay the rest of the spectrum to match so everything arrives at the same time. Just go whole hog and biamp your 19's while you are at it, the improvement can be startling.

[LICORNE]

Hi,

In order to remain in the same category of speaker system . I recommend you look at the THX list .

As Old Guy mentioned perhaps the XO on your model 19 need upgrading.

You need to talk to someone at GPA or Iconic.

http://www.thx.com/mod/techLib/pdf/A...dEquipList.pdf

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[boltupright]

Forgive me if this sounds kind of lame but,,,,with 5 model 19's, why would you need subs?

[LICORNE]

Hi,

This guy is from LA . He probably has a screening
room with real 35 mm projectors. LA is the film industry capital of the world. They produce films
like on an assembly line. A lot of people technicians probably more than the Auto Industry in Ontario.

I've seen portable 35mm projectors stuff you don't even hear of in Canada.

It's a natural thing for them.

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[bigjunglejim]

Hello everyone....
Thanks everyone for the input.... First off, for viewing, I use a 35" Panasonic "tube" TV... I'm in the Screen Actor's Guild Film Society... We usually use the Directors Guild of America (Hollywood) theater for viewing movies.. The DGA has the very best movie theater sound system I've heard.... (the theater where the Emmies award shows are held also has a great sound system) I'd like my sound to be even better and with more and tighter sub frequencies. The reason I need subs with 5 Model 19s? Model 19s don't go low enough and what is at the very bottom doesn't come out in great abundance. When I was using 19s for stereo, while listening to high power rock music, I'd turn up the volume just shy of clipping, then I'd stand very close to the side of a speaker.. Not an ideal way of listening to a speaker but, that way I got the very most low end from the 19's. (I like a lot of clean low end).... I was using a Soundcraftsmen 5002 amp (250 RMS @ 8 ohms per channel min.)... and a Soundcraftsmen 1 octave eq. . . To get more lows, I had made the two custom 8184's loaded with 3184 drivers... I used a UREI 525 XO (bought through Stanal Sound) which I low passed at 80Hz and two more Soundcraftsmen 5002 amps, bridged (using a separate bridging device from Soundcraftsmen). Each amp for the 8184s were putting out over 750 RMS @ 8 ohms. I stacked the two model 19's on the two 8184s and ran everything up just shy of clipping. The system sounded great with pipe organ music but, when I played Michael Jackson's Thriller I was very disappointed... To tell you the truth, the 19s sounded better by themselves than with the 8184's except when long low notes were played. What a waist of money. I have less money to play with today then I did back them. This time I need to HEAR what will be added before I plunk down the cash. I talked with Bill a GPA a few years ago about using other Altec drivers for subs... He didn't think much of the idea. As he put it, the voice coils are to short to do a good job at high SPLs. Perhaps I will tri amp the 19's and subs. BSS has some very interesting units. XO, time align, EQ and limiters (cheap insurance) all in one unit. Besides subs, I need more amps.... The specs on Mackie's 1400 amps look interesting. And, they are very reasonable priced. Has anyone out there used one of these?
I'll be looking for info in the Tuba subs and the Beyma LX60 15.. (thanks Old Guy). I'm like Tim the tool man Taylor.... my motto, "MORE POWER". When Universal Studios had the King Kong bust made for the studio tour, I had the opportunity to go the industry showing. The showing was at the anamatronics fabrication shop that made the bust. The sound system had 5 Servodrive subs with Bose pa speakers used for the mains... the speakers were place evenly around the listening area with 40-60 foot diameter... That was the best low end I've heard to date. The sound felt as though it started from the center of one's body and emanated out.... instead of hitting the body and going in. I'm striveing for a similar listening experience, only with better. With the right subs and 5 19's (or 604's) for the mains, the goal will be reached. My listening area is 13.5' wide X 22' long X 8' high
As you can see. I've come back to the Altec hostboard to read the responses... Thanks again for your input... Jammin Jungle Jim

[Old Guy]

Mackie amps are terrible. Sine waves look fuzzy on the bench. Mackie is at best a second or third rate manufacturer. Sorry if I anger any Mackie fans, but I get riders constantly and one of the most common statements is NO MACKIE! The caps are theirs not mine.

If I HAD to look at budget amps the Behringer 2500 will eat the Mackie for lunch. Behringer's DCX 2496 is something also to look at. B's warranty is better- if it's defective you get an instant replacement. All low end stuff will have its issues. Frankly, a lot of high end stuff too. Midas mixing desks cost an arm and a leg and break like clockwork.

How much power and what's your budget? Often you may be better off buying a better amp used than a new cheap one.

[LICORNE]

Hi,

I'm impressed with your system. I wonder! Have you tried crossing over at a less lower fr.
supposing 150Hz or 200 hz.

Your objective is to achieve a seemless system And to get this you might have to compromise a little.

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[bigjunglejim]

Thanks for the input Old Guy and Convergence
CONVERGENCE... I did as was suggested by the master himself... Stan Miller... I played around with XO and low pass at different frequencies.. Stan was right.. it sounded best when the 19's got a full frequency signal and the the 8184's were low passed at 50-80Hs (I now forget which I used.. it's been a while).
OLD GUY... I need some amps for my sound reinforcement system... I use 8 Altec/Stanley Screamer 817-R bins loaded with 421's and 421-LF's, 8 Altec 288/291 mids with MR-94-B horns and 16 MR-94-HF tweeters (I could use another 16).... I have four custom Servodrive subs each with three motors and 6 15" cones (these were built for VERIZON and have a very unusual history)... The folks at Servodrive said VERIZON had twenty of these built. They used 9 at a time, firing down through a concrete floor into a chamber.. I was told the SPL in the chamber pegged the test meters at 160dB and the bins were flat to 5Hz. I've never used the the subs... I've never hooked them up to an amp. One day I will... I still have to get more info from Servodrive. I have two UREI 525 OX's and Soundcraftsmen 5002 (a?) amps.... I've been using the four Soundcraftsmen amps from my home for my SR rig... I'd like to stop that nonsense... Although my budgit is small, I'll do what I can.... I bought a used Altec amp on EBay only to have it smoke and catch fire the first time I plugged it in.... I went though the hoops with EBAy but... I still got screwed. I'd like to buy matching amps and know the history.... Since sound is a hobby and there's almost no financial reward... I have to be prudent and low buck. I'd like to buy some amps with balanced line ins and do something different about when aligning... I physically move the stuff back and forth as a signal generator puts out a tone at the xo frequency... I have one of the two out of phase and them look for the low spl spot while moving one of the two being aligned forward and back... once I find the "spot" I put the drivers back in phase. I'd like to move up a notch all across the board in my techniques..... I like the UREI 525's but to be able to do more than XO would be great.... It would be nice to move up the 21st century with my electronics while using the old Altec transducers.... If I had the $$$$$$$, I'd buy CREST or CROWN amps and 16 Servodrive BassTech-7's for my SR rig and 6 Servodrive Contra Bass for my home..... (more power) But unless I hit the lottery, I'll do what I can, when I can..... I've been building slowly ever since I bought my first PA to amplify my drums in 1971. You know... we do what we can do and since this is for my own amusement.. there's no rush to get it done.
Thanks again.... OH one more thing.... I still need a good sub system for each of the 5 model 19's. Any ideas?

[Old Guy]

Seriously, if you are looking for a good cheap SR amp, get one of thos Behringer 2500"s to try. 700 a side at 4, 1200 at 2 and that's an honest spec. I put 4 in a nightclub for a friend, they get pounded every night. I got those for $279 each delivered to my door. the may be a little higher now but not much. hard to argue with numbers like that.

A good place for SR info is alt.audio.pro.live-sound on usenet. they are opinionated but lots of those guys have been doing SR for years, some of them as much as 50.

Your servodrives sound impressive.