Did some frequency response and headunit clipping testing today on my Pioneer z110bt.

Setup used was the laptop, truerta, some home made wires, and the oscope.

Note:

The z110bt's volume goes from 0-40.

The testing was done only on the front rca outputs.

First off, the Pioneer Z110BT Clipping Test:

I used both a 22kohm load (rating for the bitone input impedance) and a 560ohm load via Chad's suggestion.

In this test, TrueRTA was used as the tone generator playing 1000hz, running into the headunit via AUX input. The RCAs from the headunit were ran into the oscope.

560ohm load at volume 20:

560ohm load at volume 40:

22kohm load at volume 40:

From the above testing, it is clear to see that the Pioneer z110bt does not clip at full volume under standard settings (ie: no loud, bass boost, eq, etc).

Pioneer z110bt Frequency Response Testing:

The fun stuff.

The test below used TrueRTA to run pink noise through the deck. Out of the deck, I used a home brew RCA to pin adapter, per VP Electricity's advice into an XLR cable where the response was recorded.

The pioneer has 3 'loud' settings in addition to the standard 'off' setting. So, 4 total variances in FR if you wish: "Off", "Low", "Mid", and "High".

The picture below lists the corresponding Test Number for each situation in BLUE. The red writing is for the scion headunit testing so IGNORE the RED writing for the z110bt testing.

For example, if you look below you can see that for Test Number 1 is with the volume at '5', and the Loud setting set to 'Off'.

Furthermore, Test Number 10 is a test with the volume set to '20', and the Loud setting set to 'Mid'.

You can see that testing was done at 3 different volumes, on all 4 'Loud' settings.

Combine the legend above, with the example below and you should see just how to link the Test Number to the appropriate results:

Now that you've got that as a legend, the test results are as follows...

Loudness OFF:

Loudness LOW:

Loudness MID:

Loudness HIGH:

Now, comparing all the various Loud settings at each incremental volume:

Volume = 5

Volume = 20

Volume = 40

So, you can clearly see just how the loudness curve effects the FR. Pretty interesting to see that the closest to flat you get is at full output volume with the loudness setting at any point. Definitely interesting to see just how much the FR varies with volume.

Also, note the trendline for the mid volume setting comparing the various loudness curves. Pretty substantial increase starting at 2khz, with a rise of about 5db on the 'High' Loud setting vs the others.

Also, I find it interesting how the 'off' & 'low' settings are so close to each other as are both 'mid' and 'high'. But, the 2 pair are different from the other pair by about 5db. In other words, off and low both, are about 5dB away from 'mid' and 'high'.

I'm going to do some more testing maybe tomorrow with more intervals to see the change at about every 5 stops. I'd like to see how these curves all compare at a finer resolution.

Very Interesting. This is very good research. Especially to the people that claim the Kenwood units sound so much better.

Very Interesting. This is very good research. Especially to the people that claim the Kenwood units sound so much better.

Well, quite honestly I'm not happy with the results of the FR.

Ideally you want a flat response at any volume level.

What I especially don't like is the fact that even with the loudness option turned off, you still have a contour tailored to the low end at lower volumes. Quite frankly, that sucks if you're wanting your cd player to do its job and simply play music (and not color the sound).

Now, at least the signal itself is clean up through full volume, at least in terms of distortion. But, the fact that the FR is so far from ideal bothers me.

The only REAL flaw is that you're doing it all through the front channels.... I could be wrong, but I would expect different results from the remaining channels.... I'd also be interested in seeing these test through the speakers(not the preouts) I think I read that the preouts are 4v?

Regardless... it's nice to see some real world data... who knows what these manufacturers test on for benchmark...

I also have to say that I am using a PAC TATO converter to supply signal to my factory speakers(not sub)... It's configurable and you can increase the gain.... I left it stock with my Z3(absolute lowest setting), which was perfect, as with the volume at 40(max), it was just before it got too garbbled... and initially left it that way with my Z110BT... But my findings are that the Z110BT sounded x2 better than my Z3 across the board....

I did however, juice up the PAC TATO..... and as like you're seeing, higher volume does kill quality somewhat.... But I no longer have to go that high, and I have a comfortable volume range..

The only REAL flaw is that you're doing it all through the front channels.... I could be wrong, but I would expect different results from the remaining channels....

I wouldn't expect different results. Well... maybe I would expect them from this... but in the ideal world, you would expect that you would have flat full range signal from any preout unless it's dedicated. The front end piece shouldn't limit you in any way, shape, or form. That's ideal.

The reason I did it through only the front channels is simple: I'm running an external DSP to split up the front left/right signals to 8 channels of audio so each is then separately powered by it's own amplifier channel. I only need the front preouts. I don't use any of the others.

I'd also be interested in seeing these test through the speakers(not the preouts) I think I read that the preouts are 4v?

Why?

You're not talking about a function of the headunit itself if you're running RTA on the speakers. That's a different animal and you will have such drastic results, you can't POSSIBLY deduct any logical idea of what the headunit's influence is. The only way to know what a certain source does to the signal is to test it as I've shown. Which is exactly why I did it.

Regardless... it's nice to see some real world data... who knows what these manufacturers test on for benchmark...

Well, as I've said above a few times, the real 'benchmark' would be a flat response. I'm not surprised at the loudness contours, however, I am surprised that the 'off' mode on that still yields any sort of curve at all.

I also have to say that I am using a PAC TATO converter to supply signal to my factory speakers(not sub)... It's configurable and you can increase the gain.... I left it stock with my Z3(absolute lowest setting), which was perfect, as with the volume at 40(max), it was just before it got too garbbled... and initially left it that way with my Z110BT... But my findings are that the B110BT sounded x2 better than my Z3 across the board....

Could be any number of reasons why, though, and it's best to note them:

1) Your preference may trend toward some sort of curve or sound that is not identical to the other unit

2) ^Just because you prefer it, doesn't mean that it's nominal. Again, flat is nominal. Now, if you prefer a certain sound, that's a preference. But in any sort of high end audio you always want the cleanest possible source. There should be no influence from your source or anything in line other. Even with an equalizer, if you have it set to flat, you expect it to not skew the end result. Period.

3) Preout voltage could be better on the z110bt. And, I'm not talking published mfg ratings. I'm talking about the voltage associated with maximum unclipped volume. As you see on the scope pictures, this headunit does not clip; even with a lower nominal load, which is very nice. However, I'm (again) not happy with the FR.

and as like you're seeing, higher volume does kill quality somewhat....

I'm not seeing that at all. Where do you see that?

In fact, in terms of actual sound quality, the highest volume is the best for several reasons:

1) Higher preout voltage while still remaining unclipped

2) ^ promotes a lower noise floor

3) Flattest response is at max volume

- Erin

If anyone has any questions, please ask. I'll do my best to answer anything you ask.

Quite honestly, the results speak for themselves. If you can read a graph, and read the legend (aka: dry erase board stuff), then you can figure out what's going on here.

Of course, it may not even matter to you, which is fine.

But, in the spirit of sharing and learning, I wanted to put this out there.

Again, look at the graphs, look at the legend. pretty straightforward. Don't get caught up in all the jargon.

I have a small problem with FM frequencies Tuning, Its jumping 2 steps in manual search, 90.3, 90.5, 90.7 … and so on.

I need to make it jump 1 step only 90.3, 90.4, 90.5 .. etc …

Any ideas ??

Regards.