Hi!
I'm doing some tests and bypassing my main unit for the VR and finding the cuts are slightly cleaner doing my own IRIAA in the box, but sound wise the balance isn't quite right yet, its nearly there but needs tweaking and wondered from anyone who is doing this, did you find getting a flat response was best doing the curve on pink noise, or did you find it easier matching to a piece of music you know well?
Currently I am doing it with pink noise, recording it flat, setting at 'EQ Match' plug in and tweaking to what look like a nice flat response, but when cutting music its a little off, sounding good but still needs tweaking and wondered if anyone had any thoughts or tips?
VR IRIAA EQ Tweaking.....
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
Re: VR IRIAA EQ Tweaking.....
Personally I've done both methods; cutting pink noise and music I know well and which has a wide frequency range.
Then I've used both to find the right balance in my final cutting eq.
Then I've used both to find the right balance in my final cutting eq.
Re: VR IRIAA EQ Tweaking.....
Can you give more detail about the process you are using? How do you know you are recording 'flat'? How are you analysing the response of the head? FFT or RTA? This process has been described several times on here, in great detail. It may be that all the answers are already here...
Re: VR IRIAA EQ Tweaking.....
Hi,
The problem with using a noise source is that its hard to determine if you are seeing the real frequency response of your system vs. the residual noise floor. This is more of an issue at the low and high frequency extremes. At low frequencies, playback and/or cutting turntable rumble might dominate and indicate more bass is present than there really is. At high frequencies, the response of the head may fall below the noise floor and cause indication that the head has better response that is really true. I have found that there are a few things that can help.
Use program material for your test cuts rather than noise and use this as a reference spectrum to match when doing your corrective EQ.
Apply a known high frequency pre-emphasis to your test cut to help pull the high frequencies out of the mud in advance. You could do the full IRIAA up front, but this results in over EQ of the mid range frequencies. The reason is that the velocity response of a typical moving coil cutter rises at +6db/oct below the main system resonance. If you look at the IRIAA curve, you can see that it also rises +6db/oct from 50 to 500 Hz. So if you apply the full IRIAA to the program material, you are over EQ'ing in this region. A better approach is to only do the IRIAA curve from 2122 Hz and use that as your pre-emphasis. You could also add in some low frequency boost below 50 Hz to fully follow the IRIAA curve. This will help pull the highs and lows (if you elect to boost below 50 Hz) out of the noise floor and make them easier to correct. If you use this approach, apply this known pre-emphasis along with your corrective EQ in a two step process prior to making your final cuts.
When using program material as your test cut source, A/B your program reference (with no EQ applied) to the test cut (with pre-emphasis and corrective EQ applied) and verify by ear that your corrective EQ is resulting in a good match.
Note I do not have a VR and do not know if this approach applies to this head design. Make measurements and use caution.
As a final note; I have a IRIAA PC based VST plugin I developed that has only the 2122 and 50 Hz boosts present. I created this originally to work with Presto moving iron heads. This will also work to provide the pre-emphasis mentioned earlier. If you PM me with you email, I'll send it along.
Hope this makes sense and is helpful.
Mark
The problem with using a noise source is that its hard to determine if you are seeing the real frequency response of your system vs. the residual noise floor. This is more of an issue at the low and high frequency extremes. At low frequencies, playback and/or cutting turntable rumble might dominate and indicate more bass is present than there really is. At high frequencies, the response of the head may fall below the noise floor and cause indication that the head has better response that is really true. I have found that there are a few things that can help.
Use program material for your test cuts rather than noise and use this as a reference spectrum to match when doing your corrective EQ.
Apply a known high frequency pre-emphasis to your test cut to help pull the high frequencies out of the mud in advance. You could do the full IRIAA up front, but this results in over EQ of the mid range frequencies. The reason is that the velocity response of a typical moving coil cutter rises at +6db/oct below the main system resonance. If you look at the IRIAA curve, you can see that it also rises +6db/oct from 50 to 500 Hz. So if you apply the full IRIAA to the program material, you are over EQ'ing in this region. A better approach is to only do the IRIAA curve from 2122 Hz and use that as your pre-emphasis. You could also add in some low frequency boost below 50 Hz to fully follow the IRIAA curve. This will help pull the highs and lows (if you elect to boost below 50 Hz) out of the noise floor and make them easier to correct. If you use this approach, apply this known pre-emphasis along with your corrective EQ in a two step process prior to making your final cuts.
When using program material as your test cut source, A/B your program reference (with no EQ applied) to the test cut (with pre-emphasis and corrective EQ applied) and verify by ear that your corrective EQ is resulting in a good match.
Note I do not have a VR and do not know if this approach applies to this head design. Make measurements and use caution.
As a final note; I have a IRIAA PC based VST plugin I developed that has only the 2122 and 50 Hz boosts present. I created this originally to work with Presto moving iron heads. This will also work to provide the pre-emphasis mentioned earlier. If you PM me with you email, I'll send it along.
Hope this makes sense and is helpful.
Mark
Re: VR IRIAA EQ Tweaking.....
That is all extremely helpful, thanks! Mark i will PM you my email address.
As for more detail, what i have been doing is taking a 0db pink noise WAV, and playing it straight into the cutter amp (at around -18dbu to avoid any issues...), cutting the signal and then recording it back in to my DAW, no processing of the pink noise, just playing, cutting and recording it. I then match the EQ to the original file to try and get it as close as possible (that is what i meant by flat, maybe not the best way of describing it). But at this point, using that EQ curve on other music isn't quite right.
I suppose as Mark said, the noise floor also plays a part in this spectrum and might not be helping with this. I have found various threads on here with this kind of info, but most people saying to use pink noise, but as i am not quite getting it right i thought its good to ask for some direct advice.
Anyway, for now that is all really helpful and will do more tests soon
As for more detail, what i have been doing is taking a 0db pink noise WAV, and playing it straight into the cutter amp (at around -18dbu to avoid any issues...), cutting the signal and then recording it back in to my DAW, no processing of the pink noise, just playing, cutting and recording it. I then match the EQ to the original file to try and get it as close as possible (that is what i meant by flat, maybe not the best way of describing it). But at this point, using that EQ curve on other music isn't quite right.
I suppose as Mark said, the noise floor also plays a part in this spectrum and might not be helping with this. I have found various threads on here with this kind of info, but most people saying to use pink noise, but as i am not quite getting it right i thought its good to ask for some direct advice.
Anyway, for now that is all really helpful and will do more tests soon
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Re: VR IRIAA EQ Tweaking.....
Do try out Markrob vst,its simple and the Presto version has worked really well with my Audax rh5!
Big up and thanx again Mr.Robinson
Maximum respect
Patrick
Big up and thanx again Mr.Robinson
Maximum respect
Patrick