8mm Forum: Any ideas on how to improve sound?

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Posted by Dave Velazquez (Member # 3009) on July 23, 2012, 06:05 PM:

Hi all! I'm new to the forums here and I want to say first how much I enjoy reading about all of the enthusiasm for the various film formats. Particularly Super 8mm which I am a fellow collector. It's awesome to see how I'm not the only one who is charmed completely by watching movies on film!

Lately I have been having screenings for some of my friends and family and they all enjoy the experience more than they even thought they could. The kids seem to be the most excited and think its 'neat' to see the film and projector in action. However, if there is one complaint they all share it's the sound of the projector.

Has anyone ever tried to connect an external speaker to an Elmo ST 600?

And am I crazy to think I might be able to muffle the sound of the projector by
putting a box over it (with space cut out for the lens of course)?

Thanks!

Posted by Wayne Tuell (Member # 1689) on July 23, 2012, 06:40 PM:

I'd guess the st600 would have the same aux out as the st1200 so hooking up for external speaker(s) should not be an issue.

You are not crazy trying to muffle the sound. I have seen portable home made sound booths for projectors. The more thought you put into it, the more projector sound you can hide.

Posted by Hugh Thompson Scott (Member # 2922) on July 23, 2012, 06:59 PM:

Years ago when I first left home,I indulged in the hobby and made a "blimp"for the purpose of cutting out the anbient light and muffle projector noise as well.It was a three sided free standing affair with detatchable roof and a hole through which to project
with variable masking to suit the picture on screen,making it
very much brighter.The thing is when I vacated my flat (apartment), I left it, the old chap who worked for the local
council, thought I had been putting on puppet shows!

Posted by Joe Taffis (Member # 4) on July 23, 2012, 07:26 PM:

Dave, you can run a line from the aux. out (as Wayne suggested) to an input line on a stereo amp (like I do), and play the sound through your home entertainment set-up, if you have one. Its nice because you can use your remote to control the volume.You just need to use a split cable connector for the left & right channels (speakers) [Smile]

Posted by Gary Crawford (Member # 67) on July 24, 2012, 08:18 AM:

I know folks who have made wooden boxes to go over their projectors.....but there are two pitfalls. One...which one guy I know was able to handle...that's heat. He ended up putting a hold on top of the box, on which he put one of those small computer fans to quietly draw out the hot air.
The second more complicated pitfall...is focusing. Sometimes films need refocusing or fine focusing more than once during a film...and it would be very annoying to you and your audience to have to lift up the box every time you had to use the focus knob. I suppose you could cut a small hole in the side of the box and use a pair of pliers or something to turn the focus knob. You more mechanically minded collectors may have rigged p more elaborate devices.

Posted by Steve Klare (Member # 12) on July 24, 2012, 08:43 AM:

Another problem you can run into is the chatter in the sound that comes because the flywheel and roller don't completely smooth the intermittant motion of the film at the gate.

This sounds a lot like the mechanical sound of the projector so the machine normally masks it, but when you silence the machine you begin to notice it through the speakers.

I've heard that every super-8 machine has this problem to some degree, but I know based on my own ST-800 it can be worse depending on the condition of the machine. Mine had it pretty steadily until I got a chance to replace all the guides with mint condition ones. Now it's rare to hear it. I think the worn sound chute guide wasn't keeping the film flat on the heads.

Something you also need to watch out for is ground loops, especially if you are working through an amplifier. If your projector and stereo aren't grounded at the same location the difference in ground voltage winds up being part of the audio signal and you can get some pretty awful sounding hum in the bargain.

I've noticed too that when you hook a big speaker into a projector, even without the amp, the larger speaker's better bass response does a much better job bringing up the regular hum the machine always has even without an amp hooked up.

Remember: Elmo ST's are expecting an 8 ohm speaker. If you happen to hook in for example 4 Ohms, you will be sorry. (Afterwards, you can put it up on E-bay as a "Rare Elmo ST-600 Silent Projector".) Most speakers are 8 Ohms, just make sure!

PS: If you can make an external audio settup work well, it can be spectacular, it just doesn't always work pefectly the first try. Persistance!

I poked around with mine (on and off) about 6 years before I got something I really liked!

Posted by Vincent Zabbia (Member # 2453) on July 25, 2012, 10:32 AM:

Be on the look out for the Eumig Projector Extention Speaker. It sounds great and has a long cable and a DIN plug at the end of it.

Posted by Dave Velazquez (Member # 3009) on July 25, 2012, 11:01 AM:

Thanks for all the great info!

I will certainly put some things to the test this weekend. I have a couple of speakers tht might do the job. And will definitely make sure the ohms are correct. But the aux out sounds very enticing.

Puppet shows? Ha! That made me laugh.

Posted by Steve Klare (Member # 12) on July 25, 2012, 12:07 PM:

Another important thing is that External Speaker output is for one (1!, solo!, single!) 8 ohm speaker only!

You put two(2) in parallel: you really have 4 ohms total (boom!)

You put two(2) in series: you really have 16 ohms. No boom!, but only half the maximum volume. This will mean you are driving the internal amp higher in voltage to get as loud as you want (assuming you can get there at all), which often means more distortion.

If you really want multi speaker sound, the best way is to go through the aux out jack and an amplifier.

Different outputs have different jobs:

Aux Out (1/8" phone jack)=Amp input only (Aux Out would barely be audible driving a speaker, too little power.)

Ext Speaker (DIN loudspeaker jack)=External Speaker only (Ext Speaker output will probably wipe out your Amp input section, too much voltage)

Good Luck: Have Fun! (...isn't that why we do this?)

Posted by Paul Adsett (Member # 25) on July 25, 2012, 12:36 PM:

BEWARE
The Eumig external speakers are 4 ohms. DO NOT use with Elmo's or any other projectors requiring 8 ohm speakers.

I have found the best way is to run from the earphone jack of the projector into a 10 band graphic equalizer and then into a stereo system. You can then adjust the equalizer frequencies to filter out low frequency hum and high frequency hiss and get the best sound from your particular projector and film.

Posted by Osi Osgood (Member # 424) on July 25, 2012, 01:00 PM:

Clean the sound heads. Amazing as to how much sharper the audio can be from your projector with a proper cleaning, (I'm surpised no one said that yet.)

Posted by Steve Klare (Member # 12) on July 25, 2012, 01:27 PM:

We were waiting for you, Osi!

Paul, do you do anything to accomodate multiple projectors for changeovers?

I have a little box with a DPDT switch inside, but I'm working on something a little less awkward to use on the fly.

I want to incorporate an equalizer into my system, but I have to wait until the existing TV dies (...long story)

Posted by Lee Mannering (Member # 728) on July 25, 2012, 02:20 PM:

Hi Dave. Going back a bit to the 1930’s they used to make a blimp (basically a wooden box) which used to have effectively carpet underlay inside it to dampen down the sound of the projector, sort of a mini sound booth if you know what I mean. If you decided to make one leave room around the projector for air to move around it and you will need a vent in it where the lamp blower flushes the hot air away from the projector. I had a mini projection room for my Eumig projectors over 30 years ago which was made from thick plywood and sound proofed with carpet underlay inside which worked a treat, I also lost a stone in 12 months! [Wink]

Posted by Paul Adsett (Member # 25) on July 25, 2012, 03:15 PM:

Hi Steve,
I do not do changeovers, but all my audio inputs from Blu Ray, DVD, CD, and super 8, go through the same 10 band equalizer via a multi-channel A/V switch. So If you had 2 projectors , the same type of switch could be used to switch the audio output from each of the projectors into the input of the equalizer.

Posted by Graham Ritchie (Member # 559) on July 25, 2012, 05:07 PM:

Just adding to what Paul has already said, a Graphic Equalizer works really well with film, wired in line between your projector and amp. You can pick them up reel cheap, second hand as a separate unit. If you have more than one projector, then a four way audio selector switch, or more [Smile]

can be fitted with the inputs from all your projectors etc plugged in, with one L/R out from the audio selector going to the Equalizer.

Graham.

Posted by Dave Velazquez (Member # 3009) on July 25, 2012, 06:05 PM:

All these tips are really fantastic....thank you!

Hey Lee..I was actually considering the padded interior route. I guess it's a no brainer.

And to think I had an equalizer in my hands for free that I let go because I didn't think I could use it...ugh!

And cleaning the sound heads...of course! Sorry for sounding young and naive but I'm still new to the hobby.

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