[1tuffchevy]

Hi. I'm using my iMac hooked up to a surround system via optical out. One thing I'm trying to figure out: Equalizers.

I realize that there is an equalizer built in, but that seems to equalize EVERYTHING.

Is there a way to equalize just the front speakers, another setting for the rears, another for the center channel, another for the subwoofer? I would like seperate EQ settings for each channel!

If apple's dvd player app doesn't do this, does another application do this? Thanks!

[Goldfinger]

Your surround receiver has to do the equalizing. Optical out passes the pure Dolby Digital or DTS track through to the receiver who handles the decoding and equalizing.

[1tuffchevy]

Originally Posted by Goldfinger 

Your surround receiver has to do the equalizing. Optical out passes the pure Dolby Digital or DTS track through to the receiver who handles the decoding and equalizing.

So I can't equalize it before it gets to the receiver eh? Lame....because the receiver only has adjustments for bass, mid, and treble.

[shaun3000]

Well it's not lame, really. Your Mac is doing the exact same thing a DVD player would do if hooked up digitally to a receiver. All the DVD player does is pass the digital signal, be it Dolby Digital (AC-3), DTS, or PCM. If you have a sound card with 6 channels, you can connect it via analogue cables and equalize those, but that defeats the whole purpose.

[centerchannel68]

Yes, but a DVD player is a boring piece of hardware, whereas a computer has the ability to have new programs written for it and installed to solve problems, so I was hoping someone remedied this situation.

[imitchellg5]

There was an equailzer on the Apple website download section once, but it was a RAM and processor hog.

[Gossamer]

You have a Dolby capable receiver that can't adjust channel volumes? Ouch.

[jebjeb]

What are you meaning when you say "equalization"?

Are you having trouble with an overly bright or dead room?

Do you have some booming or overwhelming areas of the frequency range?

Or do you just want to alter the volume levels of the individual channels?

What receiver do you own that can accept an optical digital input but only has the "standard" two channel tone and balance controls? Is the original poster Rob? If so, I know what gear you have but if it is not Rob, I would be surprised if you had a two channel amp/receiver with a built in DAC or a multi-channel amp/receiver with no surround processing.

Again, it depends on if you want to truly equalize (which I think, unless done well, is a waste of time) or if you just want to vary channel levels.

What amp/receiver do you have?

[jebjeb]

Just had a look, if it is just that you can't alter channel levels, I would look at one of these , Griffin Firewave.

It will let you output 6 individual channels in analogue form with separate level controls just waiting to be hooked up to your amp channels.

[centerchannel68]

Originally Posted by Gossamer 

You have a Dolby capable receiver that can't adjust channel volumes? Ouch.

You don't know the difference between equalization and amplitude? Ouch.

They are VASTLY different.

[centerchannel68]

Originally Posted by jebjeb 

What are you meaning when you say "equalization"?

Are you having trouble with an overly bright or dead room?

Do you have some booming or overwhelming areas of the frequency range?

Or do you just want to alter the volume levels of the individual channels?

What receiver do you own that can accept an optical digital input but only has the "standard" two channel tone and balance controls? Is the original poster Rob? If so, I know what gear you have but if it is not Rob, I would be surprised if you had a two channel amp/receiver with a built in DAC or a multi-channel amp/receiver with no surround processing.

Again, it depends on if you want to truly equalize (which I think, unless done well, is a waste of time) or if you just want to vary channel levels.

What amp/receiver do you have?

Yes, this is Rob.

Here's what I wanted to do: I wanted to play a frequency sweep from 20hz to 20khz, and use a mic to figure out what frequencies need a little boost, and which ones need to be quieted down a bit. Since I have 4 identical speakers, the surrounds should be easy, but my center channel is NOT identical, thus will have a totally different curve of what frequencies are loud, and what frequencies are softer.

With individual channel equalization I could tune the center channel and the surrounds so that they'd all reproduce sound as accurately as possible to the original source.

[macmad]

How about this? Electroacoustics Toolbox

[jebjeb]

Right, so this is using your Technics SA-AX720 receiver for decoding then. You have a few options.

Find some software that can equalize encoded channels from a DVD on the Mac and then shoot them down (after being equalized) the Toslink to your AX720 for decoding and internally amplified then to your speakers. To be honest, I don't like your chances with this one.

I think your better bet would be to get the Griffin Firelink I linked to before, let it do the decoding and leave all equalization to some thing like this 7 Channel equalizer - quick review. The Firewave would connect via miniplug to RCA phonos to the EQ and then from RCA to RCA from the EQ to the 6 channel input on your AX720.

This has enough bands to work with effectively and may match up with your gear quite well. I am generally in the "non-equalizing" camp but could certainly understand you giving it a go when you have a centre speaker that is completely different to your mains. I use three identical B&W 602 standmounts for my Left, Centre and Right in my home theatre.

Another option is for you to just equalize the centre channel to get it to match up a little more with your mains but that may be pushing the equalization a bit far.

How about building a couple of main speakers out of acrylic using the same sort of gear as your centre? You could either use some bigger drivers for the midbass or use an extra pair of the ones you are currently using for each speaker.

How do you plan on measuring the frequency response of your system in your room? You just going to use a SPL meter or something a lot more complex like the software that macmad linked to?

[Gossamer]

Originally Posted by centerchannel68 

You don't know the difference between equalization and amplitude? Ouch.

They are VASTLY different.

Oh great possessor of all knowledge, please explain to poor humble old me what the difference is.

[centerchannel68]

Originally Posted by jebjeb 

Right, so this is using your Technics SA-AX720 receiver for decoding then. You have a few options.

No no no. I'm using my quadraphonic amp, along with a technics SU-7700 to power the center and shakers.

I have a technics SH-A500 dts/dolby digital decoder, that splits the optical signal into 6 RCA jacks. I can adjust individual channel LEVELS, but I can't equalize individual channels.

- Rob

[centerchannel68]

Originally Posted by Gossamer 

Oh great possessor of all knowledge, please explain to poor humble old me what the difference is.

Amplitude= loudness. Same thing as the volume knob on your boombox.

Equalization= megabass, classical, jazz, rock (these are all preset equalizer settings popular on lower end stuff... real equalization allows you to bump up certain frequencies and tone down others, so that you get an even response, or even 'amplitude' across the entire frequency spectrum.

[Gossamer]

Hm...I thought that was obvious. Fortunately my "boombox" is quite capable of adjusting the volume levels on each channel, but what the heck does all of that 'dolby' stuff on the front of it mean?

[centerchannel68]

Are you joking?

PS: Dolby sucks.

[Gossamer]

Originally Posted by centerchannel68 

Are you joking?

PS: Dolby sucks.

Was I winking?

PS I'm actually leaving right now to take a sledgehammer to every piece of audio equipment I own. Turns out even though I thought it's great, it's actually not.

[centerchannel68]

Whatever dude. Go do whatever you want.

[Doofy]

Originally Posted by centerchannel68 

No no no. I'm using my quadraphonic amp, along with a technics SU-7700 to power the center and shakers.

I have a technics SH-A500 dts/dolby digital decoder, that splits the optical signal into 6 RCA jacks. I can adjust individual channel LEVELS, but I can't equalize individual channels.

So you're outputting the 5.1 signal in analogue before it gets amplified?

Just go buy an Alesis DEQ 830.

[jebjeb]

Originally Posted by centerchannel68 

No no no. I'm using my quadraphonic amp, along with a technics SU-7700 to power the center and shakers.

I have a technics SH-A500 dts/dolby digital decoder, that splits the optical signal into 6 RCA jacks. I can adjust individual channel LEVELS, but I can't equalize individual channels.

- Rob

Well that makes it even easier and cheaper as you don't need something i.e. Firewave, between the iMac and the amp to decode the stuff.

Do what Doofy suggested or what I earlier mentioned which should work out cheaper.

[Gossamer]

Originally Posted by centerchannel68 

I have a technics SH-A500 dts/dolby digital decoder, that splits the optical signal into 6 RCA jacks. I can adjust individual channel LEVELS, but I can't equalize individual channels.

- Rob

Dolby sucks. Destroy it.

[centerchannel68]

Originally Posted by Doofy 

So you're outputting the 5.1 signal in analogue before it gets amplified?

Just go buy an Alesis DEQ 830.

That would work, I just don't get why there isn't a program in OSX that can do this. It's just equalization, and I'm trying to do it with the CPU, instead of buying another piece of hardware.

[centerchannel68]

Originally Posted by Gossamer 

Dolby sucks. Destroy it.

I got the model with DTS decoding, so I don't HAVE to listen to dolby if the DVD has DTS also. Nice trolling though.

[Doofy]

Originally Posted by centerchannel68 

That would work, I just don't get why there isn't a program in OSX that can do this. It's just equalization, and I'm trying to do it with the CPU, instead of buying another piece of hardware.

At a guess, Apple have agreements with the film studios to not allow access into the DVDPlayer>5.1 stream because it'd make piracy easier? Thus the details needed for a coder to do such a thing haven't been released?

Just a guess. I'm not a coder, so...

[ghporter]

Originally Posted by Gossamer 

Dolby sucks. Destroy it.

How, pray tell, does "Dolby suck?" For the appropriate media, it's great. For many forms of recording it's almost essential to have Dolby or Dolby-like noise elimination built into the reproduce system because of the way the original signal was processed on its way to being recorded.

So what's your beef with Dolby?

[Gossamer]

Originally Posted by ghporter 

How, pray tell, does "Dolby suck?" For the appropriate media, it's great. For many forms of recording it's almost essential to have Dolby or Dolby-like noise elimination built into the reproduce system because of the way the original signal was processed on its way to being recorded.

So what's your beef with Dolby?

Originally Posted by centerchannel68 

Are you joking?

PS: Dolby sucks.

I think it's great for what it's meant for, but other than that I have no strong opinion either way.

[imitchellg5]

Dolby Pro Logic II is okay for games, but sucks for music.

[ghporter]

Not joking. Any ANALOG sourced audio (let's call it "classic" audio) is going to have tape hiss from its original recording. Even great processing in the digitizing process will only handle so much hiss, so a decent "Dolby-like" system that identifies hiss and blocks it-without blocking the high frequency signals-is important for that sort of media. As I said "For the appropriate media," not 'for everything.'

No, I don't still depend on my cassette collection-I moved to CDs long ago. But I do have quite a collection of "AAD" type CDs and having a decent hiss-remover has helped me decide on which player (or more appropriately, which receiver/amp) to get on a number of occasions.

With the number of "classic" audio originals becoming smaller and smaller, I see the need for outright hiss elimination becoming a niche technology and more and more simple "noise" elimination coming forward, and becoming so deeply embedded in every digital reproduction system that it's not just expected but ignored. If the listener ignores the fact that it's there, that doesn't change its effect, just the impression the listener gets.

I keep seeing "audiophiles" post about how they only ever get the highest-priced CDs because they "can hear the difference between the gold discs and the cheap ones" and that they "hear artifacts on mass-market CDs," but I respectfully believe they're full of it. I have enough of a background in audio processing to be able to SEE when there's hiss, artifacts and noise in a sound signal, and I have yet to have one of these "audiophiles" actually demonstrate a difference between the high-dollar gold CDs and the mass-market version - given identical disc conditions and players. The difference is the way these folks tweak their systems, adjust their EQs and otherwise listen differently. A big part of that is (getting back to the point) noise elimination. Dolby was great at its time, and for certain uses it's still a good thing.

[Doofy]

That's all well and good Glenn, but you don't want to be doing heavy metal in Dobly. Seriously.

[imitchellg5]

I'm pretty sure that is what he basically said.

[ghporter]

Heavy metal? Heck no! Dolby would destroy and/or distort all the INTENTIONAL distortion, harmonics and other brain-jelling loveliness of really classic heavy metal. But there were a lot of good, less "intense" instrumentals and stuff from the "all analog" era that do benefit from some sort of simple-minded noise elimination. And every LP I've captured to MP3 needed every bit of clean up that the MP3 program I used had (a couple of them took running the clean up twice!). Beggar's Banquet turned out to be a trial because the disc wasn't as clean as it looked-I washed it with soap and water and it worked the second time, without pops or hiss!

[centerchannel68]

Originally Posted by ghporter 

How, pray tell, does "Dolby suck?" For the appropriate media, it's great. For many forms of recording it's almost essential to have Dolby or Dolby-like noise elimination built into the reproduce system because of the way the original signal was processed on its way to being recorded.

So what's your beef with Dolby?

He's attempting to be sarcastic and trying to bait me into arguing with him. I said that lower end electronics usually have 'classical, pop, rock' equalizer presets', because real audio equipment doesn't have all those cheesy presets... and then he took offense to that, claiming that I was saying all his equipment was garbage, so now basically he's being a big wuss and getting sand in his vagina.

Originally Posted by centerchannel68 

That would work, I just don't get why there isn't a program in OSX that can do this. It's just equalization, and I'm trying to do it with the CPU, instead of buying another piece of hardware.

Because nobody would use it. Your Mac would first have to decompress the stream, apply the equalization and re-apply compression (lossy compression at that) and then resend it.

Ignoring the high level of RAM and CPU time it would involve, how much demand do you think there is for such a feature? Only a handful of geeky users would know what to do with that feature - and most of those users would rather just go buy a matching center channel speaker instead because they wouldn't want the loss of sound quality in re-encoding the audio.

It's not surprising that feature doesn't exist.

Since you have an outboard decoder, why not get an equalizer and put it on your centre channel?

[centerchannel68]

I was trying to avoid equipment. I guess I'll have to.

[centerchannel68]

Okay... I just got an infraction. Does anybody know how I was derailing this thread? I don't understand. I was trying to explain why Gossamer was acting the way he was, because a moderator of these forums asked. ?!

[Person Man]

Originally Posted by centerchannel68 

Okay... I just got an infraction. Does anybody know how I was derailing this thread? I don't understand. I was trying to explain why Gossamer was acting the way he was, because a moderator of these forums asked. ?!

My guess would be the language you used in your explanation to said moderator.

If you had said you were being sarcastic because the other poster was being sarcastic and trying to bait you into an argument and left it at that you probably wouldn't have gotten the infraction. But you went further than that and said some things that could make the other poster angry... that could then lead to a thread derail.

But hey, you got an infraction and not an outright ban. Don't waste this opportunity.

[Gossamer]

Originally Posted by centerchannel68 

Are you joking?

PS: Dolby sucks.

Oops, turns out there's a bunch of DTS stuff all over it too. Same with my other receiver.

[centerchannel68]

DTS is sweet. Use that whenever possible.

[Gossamer]

Originally Posted by centerchannel68 

DTS is sweet. Use that whenever possible.

I'll try. I still need to get a powered sub built for my other receiver. Then I'll be good to go.

[centerchannel68]

Build one. If you need help let me know. Building one= best bang for your buck.

[Gossamer]

Originally Posted by centerchannel68 

Build one. If you need help let me know. Building one= best bang for your buck.

Originally Posted by Gossamer 

I'll try. I still need to get a powered sub built for my other receiver. Then I'll be good to go.

I was planning on it.

What would you suggest for an amp? I've been scouring eBay and I haven't found much in my price range (cheeeep). Craigslist around here kinda sucks. I have a 1 cubic foot box that I built a while back for a home theater sub that I'd been using in my car until yesterday when I got my real enclosure built. I'd like to use that if possible, but I do still have over half of a 4x8 sheet of 3/4" MDF left over if I need to build a new enclosure. I'll be moving into a real house this summer/next fall, and it would be nice to have a sweet surround sound setup.

edit: This any good?

Or this?

[centerchannel68]

The second one is good, if you're driving a small sub. It depends on how much power you need/want. Generally, I feel it's safer to have a HUGE amp, so you have more watts than your speaker is rated for. Yes, you can blow your speakers, but it's much more dangerous to have a wimpy amplifier, so that it distorts at high volume and produces clipping.

Check out all these:

Search Results Page

Personally, if I was in your position and had the money, I'd JUMP on this deal:

eBay: Dayton SA240 240W Subwoofer Amplifier (item 320068688680 end time Jan-12-07 11:39:21 PST)

$100 for a 240 watt sub plate amp is a screamin' deal and a half.

[residentEvil]

man, where was a surfing; "huge price reductions" on sub plate amps and crossovers/whatnot.

hmmm, damn it all...maybe it was on my work machine.

[centerchannel68]

Madisound?

[Gossamer]

www.partsexpress.com

hehe

I remember an article a long time ago about how their site got filtered by filtering companies because of that.