Mr.T Posted January 12, 2009 Share Posted January 12, 2009 I would apologise for my lack of knowledge on this subject, but being a career-long Trace Elliot slider user I feel kind of justified asking this question.... Ok, so the two mid frequency selection controls on my SA450 are marked: Low Mid: 100 to 800mhz High Mid: 700mhz to 6 khz ... and each can be cut or boosted 16db. So far, so good, but... I assume that the frequencies are not linear, so how do I work out what the centre positions are (Or any point within the sweep). I hope that makes sense? (I have a need to know these things... I know it might sound a bit anal). Quote Link to comment Share on other sites More sharing options...
alexclaber Posted January 12, 2009 Share Posted January 12, 2009 You're better off learning what the different knob positions sound like than what the frequencies are - just like when learning an instrument it's usually more useful to be able to hear a note and play it than read a note and play it. Boost the knob all the way and sweep it to suss out the sound. Do the reverse to suss out what losing that region does to your sound. Alex Quote Link to comment Share on other sites More sharing options...
bass_ferret Posted January 12, 2009 Share Posted January 12, 2009 What he said. Just f*** about and find out what sounds you like and what sounds you dont like, preferably at band practice not at home. You can get a double whammy between 700 and 800 hz Quote Link to comment Share on other sites More sharing options...
Mr.T Posted January 12, 2009 Author Share Posted January 12, 2009 Thanks guys. I have done the twiddling and listening... albeit mainly at home... Band practice, now that would be a luxury! I said it was an 'anal' question. So you don't know the answer then, eh? Quote Link to comment Share on other sites More sharing options...
Prosebass Posted January 12, 2009 Share Posted January 12, 2009 (edited) Find 450Hz nearest to which is A4 (440hz) and 3350Hz which is almost A flat 7 (both mid points of the frequency ranges) and repeatedly play each note (easier with a capo) whist twiddling the associated knob and when the note is louder you can mark the pot position . Edited January 12, 2009 by Prosebass Quote Link to comment Share on other sites More sharing options...
Mr.T Posted January 13, 2009 Author Share Posted January 13, 2009 Thanks, So are you saying that the frequencies selected are not linear, i.e the 12 o'clock centre positions of the pots will not necessarily be the centre frequencies 450 and 3350? I am not just being anal here, I find it easier to work with things when I understand how they work, plus I can then transfer the knowledge of setting up the graphic on my Trace to the MarkBass amp. Quote Link to comment Share on other sites More sharing options...
Merton Posted January 13, 2009 Share Posted January 13, 2009 I would put money on the frequency pot being logarithmic. Quote Link to comment Share on other sites More sharing options...
alexclaber Posted January 13, 2009 Share Posted January 13, 2009 If you really want to understand what the EQ does then head over to talkbass, find the user 'fdeck's homepage and use his simple RTA software to see plots of what happens to the response as you turn the knobs. I've done this with my old amp and it was very enlightening! Alex Quote Link to comment Share on other sites More sharing options...
Prosebass Posted January 13, 2009 Share Posted January 13, 2009 [quote name='Mr.T' post='378669' date='Jan 13 2009, 09:47 AM']Thanks, So are you saying that the frequencies selected are not linear, i.e the 12 o'clock centre positions of the pots will not necessarily be the centre frequencies 450 and 3350? I am not just being anal here, I find it easier to work with things when I understand how they work, plus I can then transfer the knowledge of setting up the graphic on my Trace to the MarkBass amp.[/quote] The only way to find out is to do the check....they are probably log pots so the mid frequencies will be approx 1/3 of a turn. There are a lot of variables and each manufacturer is different so its just suck it and see... Quote Link to comment Share on other sites More sharing options...
51m0n Posted January 13, 2009 Share Posted January 13, 2009 Coming from a recording engineer background, and having an sa450 too, I'd definitely suggest you go with a (slight) variation on the boost it, twist it suggestion. SInce that is the ethos behind almost all mixing desk channel eqs. My variation is dont boost to max, since that is soooo much that it can make to very hard to hear anything useful. You want a good 6 to 9dB of boost and then sweep until you find a frequency you like, then back the boost right off. Play a bit more then gradually bring on the boost (otherwise you tend to over egg the pudding). Once you get the hang of it you will almost certainly find that semi parametric eqs are far more intuitive, easier to use and accurate than a graphic for tone setting. A useful piece of advice is cut first. Really, boosting an eq tends to accentuate the noise of that eq circuit, it also increases the chance of overloading things further down the chain (poweramp's limiter section in this case) which can be a bad thing! Definitely use your ears, since this isnt your Trace amp the 'same' eq settings (even if you really could get exactly the same eq settings) will _not_ give the same result anyway. It is a completely different amp design after all. IME of the sa450 I would think the eq is easily powerful enough to achieve whatever you need, and it sounds cool just about anywhere you might try it (some settings are seriously not for the faint hearted though!!) Also if you like the sound of your bass then you will probably find (as I did to my surprise) that I was using less and less eq as time went by with the MB stuff. Just a touch of Low or Lo-Mid is about it now, after carefully setting up my tweeter attenuater. It just sounds so darned nice Last point, and I know its been said again and again, but it is always worth a mention to anyone trying out MB stuff, the two 'magic' filters (VPF and VLE) are only off when rotated fully counter clockwise, whereas the eq gains are off at noon. Not trying to teach nan to suck eggs - promise! Enjoy finding _your_ sound again! Quote Link to comment Share on other sites More sharing options...
chris_b Posted January 13, 2009 Share Posted January 13, 2009 In answer to your question: I believe the tone controls are flat at 12 o'clock and the VLE and VPF are off at 5 o'clock. Quote Link to comment Share on other sites More sharing options...
Mr.T Posted January 14, 2009 Author Share Posted January 14, 2009 Simon... Thanks for some sound advice (pardon the pun). I agree that 'cutting' is the way forward, as I think that what I am trying to do with my sound is iron out a mid hump in my neo cab. I know that most people seem to mainly use the two filters to get their sound, and that is Ok... but not doing it for me. I have found that the VPF filter (which cuts at 380hz) is taking out clarity in a band setting with my cabs, and that I need to cut a little higher at about 500hz (I am guessing) to get my sound more balanced and even. My band never have the luxury of a sound check and rarely rehearse, so it is important for me to really get to know my new amp/cabs so I that I don't spend half the gig 'faffing about' getting my gear set-up. I have read that neo drivers have mid humps.... does anyone know at rougly what frequency? Quote Link to comment Share on other sites More sharing options...
51m0n Posted January 14, 2009 Share Posted January 14, 2009 (edited) [quote name='Mr.T' post='380002' date='Jan 14 2009, 09:40 AM']Simon... Thanks for some sound advice (pardon the pun). I agree that 'cutting' is the way forward, as I think that what I am trying to do with my sound is iron out a mid hump in my neo cab. I know that most people seem to mainly use the two filters to get their sound, and that is Ok... but not doing it for me. I have found that the VPF filter (which cuts at 380hz) is taking out clarity in a band setting with my cabs, and that I need to cut a little higher at about 500hz (I am guessing) to get my sound more balanced and even. My band never have the luxury of a sound check and rarely rehearse, so it is important for me to really get to know my new amp/cabs so I that I don't spend half the gig 'faffing about' getting my gear set-up. I have read that neo drivers have mid humps.... does anyone know at rougly what frequency?[/quote] Pleasure mate. The cab is as much to do with the mid hump as the driver, so I think the question is does anyone know what the mid hump frequency is for cab blah - which I dont. My suggestion for how to go forward would be as follows:- Get to your next gig first and set up your rig. Plug in turn on tune up. Set your input gain with the master on 0 (usual stuff, play some hard 8th notes bring up the gain till you see the blue light and back off until you dont) Bring up the master until the cab is running but not too loud, so as not to unduly annoy the clientelle. Apply ~6-9dB (ie a healthy dose) of cut in the lo mid. Set the frequency as high as it will go for now. Play straight 8ths and sweep back through the frequencies (should take around 4 or 5 seconds to complete the sweep all the way through the frequencies). Take a mental note where the cabs stop have the mid hump, return the frequency to where it just sounded best then adjust the gain to taste. When you get really practiced you'll just go a little past the best point and then track straight back to it, which is even quicker! Total time to set the eq should be about 20 seconds - really. Even quicker when you really get the hang of it. Too much cut and you will affect that 380Hz area you like a bit too much. In which case cut less. Turn up to 'gigging grunt' master level. It wont hurt to run through the procedure a few times at home to familiarise yourself with it. Should be done before the drummer has his snare stand out of the coffin I also never seem to get a soundcheck and rehearsals are clearly for other people too, so I know exactly where you are coming from. Its a lot of the reason why I ended up investing as much as I have in my rig. I just dont have the luxury of tweaking with it when I do get to play out, in fact I even have to rush when recording and if I'm going to mic the righ for that purpose it needs to be almost spot on from the very start. These MB heads really help in that eqing a semi-parametric is so much faster than a graphic IMO. Edited January 14, 2009 by 51m0n Quote Link to comment Share on other sites More sharing options...
Mr.T Posted January 14, 2009 Author Share Posted January 14, 2009 Thanks... I'll give that a try! Quote Link to comment Share on other sites More sharing options...
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