Anyone use a parametric eq for mains? (1 Viewer)

[Kevin C Brown]

I have a BFD 1100p for my sub. I like the improvement in sound that I've gotten.
Just wondering what people's thoughts would be to use an 1124p for the mains. Not really an attempt to flatten the speaker's response, just low freq/room interaction stuff.
My pre/pro converts everything to 48/16 internally anyway, and I think the 1124p is 24 bit and 46 kHz. So I don't think I'd be affecting *that* part of the sound quality much.
Just curious!

 

[Rick Radford]

Kevin, I have the 1124P. From what I've read here and elsewhere, the BFD is a low end professional rig that won't do for the upper freq range. Suitable only for subs, as I understand it.
I suspect the solution for your mains is a LOT more expensive than the BFD.
Maybe Wayne or BruceD or someone who really knows will chime in here.
Wayne, ya got that computer back online yet?

 

[Wayne A. Pflughaupt]

Rick, YGM!
Kevin,
Rick hit the nail on the head – he’s just a little faster then me.
Not knowing what kind of equipment you have, I’d say if you have at least decent mid-fi stuff you don’t want to use the BFD on your mains. With its notoriously cheap AD/DA converters, it is better suited for subs, where artifacts like “grain” don’t make a difference.
I’d say to anyone interested in equalizing mains, take some frequency response readings first to determine what kind of equalizer – 2/3-octave, 1/3-octave or parametric – you need. (if any).
And as Rick also noted, equalizing home theater mains can get pricey, since you need one for each channel you want to adjust. And since you have to connect them between the pre amp and amplifier (as opposed to across a tape monitor loop in the “old days”) you need something a little more substantial than a $99 Audiosource from Best Buy. Decent pro-grade stuff (the best choice) from Rane, Ashly or Symetrix start at about $300 per channel (street-price, new).
Regards,
Wayne A. Pflughaupt

 

[Kevin C Brown]

Jah. The BFD is 2 channel, but I see what you mean.

I guess as a test, I could try the 1100p I have now, and just use a different program. And/or, set all the filters to "none" just to check on the A-D conversion quality.

 

[ThomasW]

The BFD sound very DDDDDDigital when used to EQ the mains. As noted the Symetrix 551 is quite good. Not only $$$ but only has 5 channels of EQ. But it looks like a steal when compared to the TCS unit from Tact. The TCS is pretty cool. Plug it in, plug the the mic, set the system to normalize the room, then stand back and watch/ it do everything automatically.

 

[Kevin C Brown]

Thomas- I think I would really need the Symetrix 552E, right? 2 channel stereo.
But I'm afraid to start looking to see how much it would be...
I also looked at the Rane PE-17 before I got the BFD for my sub. I wonder if they have a 2 channel version too...

 

[Wayne A. Pflughaupt]

I also looked at the Rane PE-17 before I got the BFD for my sub. I wonder if they have a 2 channel version too...

They don’t.

 

[Kevin C Brown]

Wayne- Rane does have the THX 22, which would be the closest for what I'd want for 2 channel stereo. But, you are right in that it's not really a parametric eq. Just sort of 1/3 octave eq with set center pts.
If you look through the Rane site, they have a link to a THX theater sound calibration document, which specifically refers to using a 1/3 octave eq:
http://www.rane.com/pdf/thxeq.pdf
But, ... I think I have come to the conclusion, that I must measure 1st to figure out what the right product would be!
(I still want to make my own test disc, now: 20 to 1280 Hz, 1/10 octave intervals. I get 60 tracks that way. But I haven't done it yet.)
I have found the Symetrix 552E for about $550 (list is $749) which isn't that much different from what 2 Rane PE-17's would cost.
But I can't remember now: didn't the Symetrix 551 get a bad rap because of how sensitive the pots were? (Somebody mentioned finally getting the right settings, and then putting a dab of superglue on each pot so it couldn't be changed.) Or am I thinking of a different eq?

 

[Wayne A. Pflughaupt]

It was the Symetrix, for the frequency control. I’m not sure why, though. I thought it might be that the Symetrix had full-range (i.e., 20Hz-20kHz) frequency knobs, but that isn’t the case. The frequency control is just like the Rane, operating over about half of the frequency spectrum, with a switch to select for low, mid and high range. So I presume if this is a problem with the Symetrix, it will be a problem with the Rane, too.

Older parametric EQs had filters that would only control a certain pre-set frequency range, like bass, mid-bass, low mid, upper mid, highs, etc. There were overlapping frequencies between the filters, but you could not, for instance, apply all three or four of them to a limited range, like below 80Hz like we want to do with home theater applications.

Late-model parametric are more versatile now in that any filter can be set for anyplace in the frequency spectrum. I guess the sensitive frequency control is the price we pay for a more flexible and useful product.

Regards,

Wayne A. Pflughaupt

 

[ThomasW]

My bad, yes the 552 is for stereo.

There's no difference between the Rane and the Symetrix as far as the sensitivity of the controls. Any of the analog processors that have rotary pots will have the sensitivity issue. How much of a problem it is depends on the 'taper' of the pot.

Also with any of the analog units some form of measurement equipment is going to be necessary to double check the settings.

BTW, the bandwidth of the Symetrix is 551/552 is 10hz to 20Khz

 

[Kevin C Brown]

OK, so in effect: 2 Rane PE-17's = 1 Symmetrix 552E.
(Just that I'm finding it much easier to find Rane units locally than Symetrix.)
... Dang, why can't Behringer or someone do a digital 24 bit/96 kHz version with really good ADCs and DACs? (sigh...) You know, for a *reasonable* price.

 

[Wayne A. Pflughaupt]

The AudioControl Diva.
Oh wait, you said “reasonable,” didn’t you?

 

[Kevin C Brown]

But Wayne- the Diva only has 2 parametric filters per channel! :frowning: Yeah, for $9g's... (For $9000, I would think that it would *include* an RTA. But it doesn't.)
Come on. Doesn't anyone out there think that it's *possible* the 46 kHz / 24 bit Behringer 1124p at $160 is as good as the 48 kHz / 24 bit Diva at $8999? Hee, hee.
I wonder if we asked (nicely), if Behringer would tell us who makes their DACs and ADCs...
Or, I suppose I could just open my 1100p and assume it's the same company when they went from 20 to 24 bits.
So the Symetrix 552E is still at the top of my list. After I get motivated, make my test disc, and then measure...
Dang, if there's anyone out there who wants to start their own company, I really think this is a niche that could be / needs to be filled. Include a calibrated microphone, and a tone and click and pop generator, and it could do everything for you.

 

[FrankD]

If you want to eq your mains and you do not want to spend too much then try the Behringer Ultra Graph Pro. It has 33 bands and eq's in the analogue domain. You may end up getting a bit more hiss in the speakers when no volume is playing but it is not very noticeable. It costs about $200US. I have used it for my center channel which is bright causing sibilance and now the sibilance is gone.

Regards

 

[Kevin C Brown]

I wanted to put this here, because the title says it all. (And see if I can get Wayne to take a peek... ).
Found another one. More expensive than the BFD, but less than the Audio Control Diva:
Link Removed
Uses AD Sharcs, so must be of half decent quality. Specs seem alright. Still a little expensive though. $1800 list or so. $1300 street or so.

 

[FrankD]

Anyone had any experience with the above noted Sabine? Is it a digital or anlogue eq?

 

[Wayne A. Pflughaupt]

It’s digital. It performs a lot of functions, but at it’s price it is probably a pretty good piece of gear – for pro use. Whether or not it is transparent enough for home theater use is anyone’s guess.
Here’s the main thing I don’t like about gear like this: The Dolby Digital encoded signal from your DVD is decoded by the AV receiver and converted to multiple analog signals. From here the analog signal would go to the Sabine and be converted back to digital. After processing, the digital signal is converted once again to analog.
I’m no audio “purist,” but I don’t find this DA/AD/DA stuff particularly appealing. It’s time for someone to come up with a universal digital interface that would allow the original signal to remain in the digital domain until it is sent to the amplifiers.
Your best bet to find someone who has actually used the Sabine is to post a question at www.live-audio.com.
Regards,
Wayne A. Pflughaupt

 

[Kevin C Brown]

Wayne- One of these days I will do this experiment:
I just got a standalone CD-R machine.
I also have a DAT deck.
What I want to try (someday) is to keep recording and playing back between the 2, for say like 10 generations. Then, compare the original with the last copy. See if I can really hear a difference or not.
Someday...