First measurements

[jasonmac]

Here is my first run with REW. I have a small sub at the moment, but am currently building a soundsplinter sub but I want to smooth out my current system and I am getting my BFD this weekend.

After moving the sub around the room, this is the best result I got. Cross-over is 80Hz, and my attempted filter is a single filter applied at 60Hz (Gain: -8, BW/60: 9).



Would you suggest a better filter or is that one ok? Can I do anything with the 20 - 30Hz valley or is it too deep to do anything about it?

Next graph is mains only, again 80Hz cross-over. I really have no idea what this graph is telling me other than it's a mess . The room is untreated, I have plans to treat the room soon. Is that all I can do? I tried shifting the speaker location around a little with no real improvements.



Next are the sub + mains graphs:



Full range:



Any points of concern in the above two graphs?

Thanks a ton for any help!

Cheers,
Jason

[brucek]

Would you suggest a better filter or is that one ok?

Is that what REW calculated and recommended?

Can I do anything with the 20 - 30Hz valley or is it too deep to do anything about it?

Re-Positioning the sub would be the only option there.

Any points of concern in the above two graphs?

Not really, other than the large peak at 60Hz that has to be dealt with. Hopefully you weren't using a Radio Shack meter for the full range...

brucek

[weverb]

brucek,

Doesn't it look like his crossover is not being applied to the mains? Shounld't the 60Hz. and 30Hz. readings be way lower than what is going on at 80Hz. and above? They seem to be adding way too much to the sub.

[jasonmac]

Thanks Bruce!

That was a filter I made up.

Here is the rew suggested filter and graph, I was worried some of the filters suggested were too narrow. What do you think?



1. Freq: 60.40, Gain: -15, BW/60: 6
2. Freq: 52.60, Gain: -5, BW/60: 2
3. Freq: 78.30, Gain: -4, BW/60: 2
4. Freq: 45.50, Gain: -3, BW/60: 2
5. Freq: 32.35, Gain: -4, BW/60: 3

Sorry, should have mentioned that I used the ECM8000 + 802 preamp.

Another question, using the phase control switch on the sub produced identical results for the normal and reverse settings for each location that I tried. Is this normal?

Cheers,
Jason

[Wayne A. Pflughaupt]

I'm with weverb, it looks like your receiver's crossover isn't working. And that 60 Hz peak from the mains is really messing up your low end. Any repositioning options for the mains? Is one of them in a corner?

Here is the rew suggested filter and graph, I was worried some of the filters suggested were too narrow. What do you think?

Of course you know that everything the sub is doing in the 60 Hz range is being blown out by the main speakers.

Aside from that - yes, some of the filters are really narrow. The 78 Hz filter probably isn't necessary; it's so close to the crossover frequency that the main speakers will over ride it (even if the crossover was working right).

The 32 Hz and 45 Hz filters probably aren't needed either. The 52 Hz filter while narrow, is probably needed, due to the sharp peak you're trying to take out. It may be too "hot" to ignore.

Another question, using the phase control switch on the sub produced identical results for the normal and reverse settings for each location that I tried. Is this normal?

You do know that the phase switch doesn't do anything unless both the subs and mains are running?

Regards,
Wayne

[jasonmac]

So I'm really confused. I know I am a complete n00b but this is a weird state for even me to get into.
Every crossover I tried for the main speakers produces exactly the same graph. So the crossover appears to be not working.

If you could please take a look at my settings I would really appreciate any help.

Here is my system and settings:

Receiver: Yamaha RX-V661
Main speakers: Jamo C805 bi-amped into the RX-V661
Receiver mode for the tests: 2ch Stereo

I ran YPAO and the adjusted the settings to the following:
Front sp: small
Centre sp: small
SUR L/R sp: small
SUR Back L/R: none
LFE/Bass Out: SWFR
Cross-over: Ideally 80Hz, but I've tried 60Hz to 200Hz
SWFR phase: normal

[weverb]

You need to look at your receiver. Does an analog input bypass the controls (i.e. crossover, etc.)? My NAD does this. It is nice for 2 channel purist. I have to send the REW signal through a digital input for those features to work. I usually send the REW signal into my dvr and out its digital output into a digital input on the receiver. Pain in the buttock at first, but no biggy now. I drove Wayne and brucek a little crazy until we figured it out.

[jasonmac]

I've tried it in STRAIGHT mode, with the graph below. Can any other Yammy users let me know what you do?

Front speakers only, STRAIGHT mode on the RX-V661.

Red: 80Hz crossover
Blue: 100Hz
Green: 120Hz



Is the crossover working properly now?

[brucek]

Is the crossover working properly now?

Looks like it is, although it's usually easier to tell if you put a target line on the graph.

Sometimes it's easier to observe the trend of a mains signal if you turn on smoothing.

brucek

[jasonmac]

I have done a sweep of different cutoffs using fronts only (red lines) and sub only (blue lines). Keeping in mind that the sub readings are without a bfd which I will have soon, which crossover will be most suitable for my system?

Regarding the front speaker placement and the 60Hz spike, I will make a separate post soon regarding my room layout. Thought this post was long enough already.

Here are my speakers that I used:
Fronts: Jamo C805
Type 2½-way bassreflex
Woofer (mm/in) 155 / 6
Midrange (mm/in) 155 / 6
Tweeter (mm/in) 25 / 1 DTT
Power (W, long/short term) 160 / 320
Sensitivity (dB, 2.8V/1m) 88
Frequency Range (Hz) 40 - 24,000
Impedence (Ohm) 6

Sub: Richter Krakatoa
Type: Dual vented
Driver: Low mass 250mm (10") cone, Ultra high excursion technology. High temp 50mm Kapton voice coil
Amplifier: 100 watts RMS <0.009% THD
Response (Hz): 22-180
Sensitivity: 86 dB/W/M
Dimensions (WxHxD in mm): 390x 420 x 390

60Hz Crossover:


80Hz Crossover:


90Hz Crossover:


100Hz Crossover:


110Hz Crossover:


120Hz Crossover: