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Discussion Starter · #1 ·
I'm trying to identify which frequencies my next HU would have to be able to adjust, as my current 3 band PEQ doesn't let me adjust all problem areas. I did a quick RTA scan in my car with my phone (haven't bought a proper mic yet) and it seems to be a big spike at 7-8k and some smaller peaks at 135, 235 and 315 (not sure if these are problematic). There is also a wide dip at 350-800hz. Other than that, I'm having trouble recognizing any problem areas from these graphs, but when I'm listening to music there seems to be something in the 2k-5k area that is way too loud. Am I missing something or is it just that the microphone on the phone is too inaccurate to give me any useful info?
 

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Discussion Starter · #3 ·
I have tried to do some EQ and this is my current result. I have set my bands as following:

120 Hz, Q 1.5, level -3
2.5 kHz, Q 1.25, level -3
7.5 kHz, Q 1.25, level -5

I don't know what scale the "level" value is, only that it boosts or cuts. If I cut the 7.5 kHz to -7 (max cut) the peak flattens but it makes the entire upper frequency range sound muffled. Idk if it actually drops off that hard after 10 kHz or if it's just the limits of the mic. Should I rather try 0 dB for the tweeters and rather cut harder on 7.5 kHz? Also, the crossovers are (if Pioneer is to be believed) set at 2 kHz. Could the dip around 2 kHz be flattened by flipping the polarity of the tweeters or is that another can of worms?

I am planning on installing a subwoofer so I will probably set HPF at 80. Hence I'm not worried about the peak at 55 Hz. The peak at 220-450 ish Hz I can't touch until I get a better EQ. Is this something that could cause the "phone speaker in a cup" type of sound? Hard to describe...

I'm still new to this, am I on the right track?
 

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I personally would not go too far into this until you can buy a proper measurement mic and leran how to use it to its full potential. Results obtained from your phone will be full of inaccuracies. The peaks and dips you see on your phone may not actually be there.


Ge0
 
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Discussion Starter · #5 ·
Thanks for your reply. Nice signature btw haha

I'll look into getting that microphone, I see that they have it at my local electronics shop. I'm fearing that getting that microphone will push me towards an active setup. I already planned on adding MLV, a subwoofer and a head unit, any thoughts on what to go for first or is that dependant on what a proper reading tells me? Having spent around $600 already on the speakers and amp without being fully satisfied got me feeling a little bit more cautios on where I put the rest of my money.
 

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To be perfectly honest, you really need a true DSP along with that measurement MIC to get good results. Having a "global" 3-band EQ isn't going to cut it. You'll never get a proper center image without the ability to make left and right match. With most DSPs, you get anywhere between 10 and 31 bands of parametric EQ per channel, which lets you really get things dialed in. Plus you get individual speaker level control, time-alignment, etc...

I realize that you've already spent a lot of money, but if you've gone this far, you might as well get a real DSP as well - you can get a "restocked" (like a refurbished unit) Dayton DSP-408 for as little as $70 - and it would make a huge improvement over your 3-band "global" EQ (which affects all channels the same). Unfortunately, the "restocked" DSP-408's are out of stock right now - you need to keep an eye on this page as they tend to sell out pretty quickly:

"RESTOCKED Dayton Audio DSP-408 4x8 DSP Digital Signal Processor for Home and Car Audio" from www.parts-express.com!
 

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Discussion Starter · #7 ·
Hmm looks interesting. The one you linked is a 4x8, is that for potentially running 3-way and sub? I might make the jump to active, however, the cheapest DSP I could find in my country is $300 used, which is why I have been reluctant. Doesn't seem like people use DSPs all that much over here. $70 isn't too bad, although I will most likely have to pay import taxes.

Might start with a DSP and a mic and run passive until I can afford another amp. The one I have now is a 2ch (PRS-D800). Would any cheap amp be enough to run the tweeters, or should I invest in a proper 4ch? It would be a waste of money if the speakers sounded like crap because of the tweeters being driven by a badly matched amp.
 

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I'm trying to identify which frequencies my next HU would have to be able to adjust, as my current 3 band PEQ doesn't let me adjust all problem areas. I did a quick RTA scan in my car with my phone (haven't bought a proper mic yet) and it seems to be a big spike at 7-8k and some smaller peaks at 135, 235 and 315 (not sure if these are problematic). There is also a wide dip at 350-800hz. Other than that, I'm having trouble recognizing any problem areas from these graphs, but when I'm listening to music there seems to be something in the 2k-5k area that is way too loud. Am I missing something or is it just that the microphone on the phone is too inaccurate to give me any useful info?
Phone mics are barely useful outside of capturing voices. You would have to calibrate the mic with a known flat responding system to get any useful measurements.
 
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Discussion Starter · #9 ·
Yeah I am going to get a proper mic next week, found a used Dayton mic for $50. After some digging I also found someone selling a Sound Magus DSP T8 (6x8) for $150. Any thoughts on this product? Can't find much info on the brand, except that they are a buildhouse for other manufacturers. Not sure what to make of that. Another option seems to be the MiniDSP 2x4 for $140, however, I would have to find a way to supply power to the unit.
 

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I personally would not go too far into this until you can buy a proper measurement mic and leran how to use it to its full potential. Results obtained from your phone will be full of inaccuracies. The peaks and dips you see on your phone may not actually be there.


Ge0
Agree... but:
In their defence though, if it is repeatable then it may be ok... and it certainly shows that they are using something as a measurement, rather than nothin.
 

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Discussion Starter · #11 ·
I have now done some measurements with a proper mic. I swapped out the head unit as well, for a Kenwood with a 13 band graphic EQ. I wish this unit had the 9 band parametric EQ that they included with their new 10.1" unit but this will have to do for now, until I get that DSP.

I did my first round of EQ-ing (30 mins maybe), and this is my current results. Not sure if I did this correctly as I am new to REW, any comments? I did the ear-to-ear thing with the mic while playing white noise (note to self, remember hearing protection next time).

First graph is the original measurement with flat EQ, -3dB attenuated tweeters. This one is smoothed 1/6, forgot to do 1/3 and 1/48.

278645


This is after EQ (1/3):

278647


And 1/48:

278648


I tried to get the graph to be ±2dB from the 580Hz dip and towards the rolloff at 8-9k. If I look at the 1/3 graph it looks like I managed to do just that. The 1/48 graph looks a little worse. However, I can't say that I can hear any big dips or peaks that stand out when listening to music, so the DSP is on hold for now.

Looking at the graphs, I can see why a 3-way would be a good investment SQ wise, as having another driver play 500-3k probably would help smooth out that area. As earlier mentioned, however, next step for me is a subwoofer, probably crossing over at 80 or 90 Hz.
 

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I have now done some measurements with a proper mic. I swapped out the head unit as well, for a Kenwood with a 13 band graphic EQ. I wish this unit had the 9 band parametric EQ that they included with their new 10.1" unit but this will have to do for now, until I get that DSP.

I did my first round of EQ-ing (30 mins maybe), and this is my current results. Not sure if I did this correctly as I am new to REW, any comments? I did the ear-to-ear thing with the mic while playing white noise (note to self, remember hearing protection next time).

First graph is the original measurement with flat EQ, -3dB attenuated tweeters. This one is smoothed 1/6, forgot to do 1/3 and 1/48.

View attachment 278645

This is after EQ (1/3):

View attachment 278647

And 1/48:

View attachment 278648

I tried to get the graph to be ±2dB from the 580Hz dip and towards the rolloff at 8-9k. If I look at the 1/3 graph it looks like I managed to do just that. The 1/48 graph looks a little worse. However, I can't say that I can hear any big dips or peaks that stand out when listening to music, so the DSP is on hold for now.

Looking at the graphs, I can see why a 3-way would be a good investment SQ wise, as having another driver play 500-3k probably would help smooth out that area. As earlier mentioned, however, next step for me is a subwoofer, probably crossing over at 80 or 90 Hz.
I hope you used pink noise, not white noise. If you used white noise start over and use pink noise.
 

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Discussion Starter · #13 ·
Of course I picked the wrong type of noise haha. What should a pink noise graph look like? A steady downward slope?
 

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Of course I picked the wrong type of noise haha. What should a pink noise graph look like? A steady downward slope?
White noise has the same intensity across all frequencies, and pink noise has the same power in each octave. If you used white noise, you likely ended up making a lot of EQ changes that weren't helpful. You still want to tune to the target curve of your choice, you just need to use pink noise to evaluate what's going on.
 

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Discussion Starter · #15 ·
Ok, so I should try to end up with the same graph as the ones I posted, only this time with pink noise?
 

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Ok, so I should try to end up with the same graph as the ones I posted, only this time with pink noise?
Yes, you still want the final graph to match the curve you are aiming for, but it needs to match that curve with pink noise, not white noise.
 

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Discussion Starter · #17 ·
Ah, thanks. I'll post graphs later when I've done the measurement and EQ.
 

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Discussion Starter · #18 ·
I tried to read up on using RTA in REW, not sure if I am doing this right. I set mode to RTA 1/48 and did measurements, then I switched between 1/48, 1/12 and 1/6 while trying to figure out the EQ adjustments. After adjusting I did new measurements and repeated the process until I ended up with this result for 1/48:

278683


1/12:

278684


1/6:

278685


1/3:

278686


Does this look like a decent EQ? It seems a little bit harsher than the EQ yesterday, might have to cut a tiny bit more at 1.6kHz. Also, when posting graphs, what smoothness should I post?
 

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Most of my experience is in home audio, so I'm going to keep it a bit vague - I don't want to sound too knowledgeable about car audio specifics.

1. Unless you have a DSP with a few bands of parametric EQ, you will have difficulties. But you may be able to make broad brush improvements.
2. Log-sweep measurements are much better than pink noise - they reduce the influence of background noise and get you phase info.
3. That dip at 550hz or thereabouts - I bet is a phase issue. Could be crossover induced, speaker position induced, or acoustics induced. Have you looked at the phase plot?
4. You should probably not try to fix phase issues with an EQ bump.
5. DSP will not just be better at EQ, it will allow time alignment Left-Right, which will affect EQ (due to phase) massively
6. Going active will open a new world of possibilities.

Just don't get too hung up on a graph if you only have a graphic EQ. Use it to know where to make some level cuts, fine tune it by ear, and live with what you have, until you get a DSP. That would be my advice.
 

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I tried to read up on using RTA in REW, not sure if I am doing this right. I set mode to RTA 1/48 and did measurements, then I switched between 1/48, 1/12 and 1/6 while trying to figure out the EQ adjustments. After adjusting I did new measurements and repeated the process until I ended up with this result for 1/48:

View attachment 278683

1/12:

View attachment 278684

1/6:

View attachment 278685

1/3:

View attachment 278686

Does this look like a decent EQ? It seems a little bit harsher than the EQ yesterday, might have to cut a tiny bit more at 1.6kHz. Also, when posting graphs, what smoothness should I post?
It looks about as good as you're going to get it using your current equipment. If you can, bring 300Hz down a few dB. But, besides that looks OK.

Ge0
 
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