# Anyone use REW to measure Yamaha RX-V1800 or RX-V3800?



## lovingdvd (Jan 23, 2007)

Anyone use REW to measure Yamaha RX-V1800 or RX-V3800?

I currently have a Yamaha HTR-6090. Unfortunately I have to use it in "Straight" mode because ALL of the other Yamaha enhanced modes (even its basic surround sound modes) add boosts in the 30-80hz range for the fronts - even if the fronts are set to cross over at 80hz!!

For instance, if I set my fronts to xo at 80hz, and then use one of those modes, the fronts will still put out a LOT of db above 80hz. Yes I am aware that it is not a cliff at 80hz and because of the curve you should still get SOME freq below the xo point from the fronts. However I was getting db well above what the xo line is in any of these modes. Switching to straight made it so that the bass sent to the subs followed the xo curve line much more as expected.

I also had this same issue with my Yamaha RX-V1400 which I had before the 6090...

At any rate, I just purchased the Yamaha RX-V1800 and it should be here shortly. I am VERY CURIOUS to know if I can use some of the basic processing modes in this receiver such as THX Cinema etc without having it screw with the bass like my Yamaha 6090 did.

Has anyone done any measurements with REW and noted what impact the various modes of the 1800 or 3800 have on the bass? Might I finally be able to use these modes without it messing up my bass?

[Note that I originally posted this question here http://www.hometheatershack.com/for.../6380-anyone-use-rew-measure-onkyo-805-a.html weeks ago except it was regarding the Onkyo 805 since I was considering that AVR at the time.]

Thanks!


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## brent_s (Feb 26, 2007)

How are you measuring this? In room measurement or at the preamp outputs. Can you post the response graphs annotated with sound mode seleted, xover setting, volume level, etc?

When you say enhanced sound modes, which ones are you using? REW signals are input to the receiver via a L/R analog input...there's no way to apply DD/DTS modes on this. However, something like "stadium" or "church" applied to a stereo signal could easily be boosting a frequency range that would create the response you've described. When you say "straight", does that mean some sort of Pure mode that bypasses all processing, tone controls, etc or is that simply normal stereo? I would expect Stereo/DPL/DD/DTS to all be flat from input to output, but like I said, the other modes are going to play with reverb, delay, frequency response, etc. to "create" the acoustical environment they're imitating. 

If your observations are based on a speaker measurement, you could also be getting output from more the the left main & sub (assuming you're using the left input channel), depending on the mode selected. To create the desired ambiance, the effect mode may send a little signal to the same side surround, center, or even the right channel. 

S&V and Home Theater Mag usually do a DD and stereo input to output frequency measurements as part of their test bench. I've never seen a unit that wasn't ruler flat in these modes.

-Brent


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## lovingdvd (Jan 23, 2007)

brent_s said:


> How are you measuring this? In room measurement or at the preamp outputs. Can you post the response graphs annotated with sound mode seleted, xover setting, volume level, etc?


This was determined using room measurements. I did this long ago and no longer have the graphs. I'll be digging back into this shortly to get my new Yamaha receiver's output configured correctly and will post what I find.

I'm assuming that as newer model the filters I need in my BFD will be different than what I have now. Do you think that will turn out to be the case? Or is there a reasonable chance that it'll be the same. I really struggled with REW (mostly my lack of experience in the matter) with inconsistent readings and frankly I'm not looking into digging back into this. I will say however that the results are well worth it! Nothing like the sound of smooth base response with a nice hot house curve!!



> When you say enhanced sound modes, which ones are you using? REW signals are input to the receiver via a L/R analog input...there's no way to apply DD/DTS modes on this. However, something like "stadium" or "church" applied to a stereo signal could easily be boosting a frequency range that would create the response you've described. When you say "straight", does that mean some sort of Pure mode that bypasses all processing, tone controls, etc or is that simply normal stereo?


Correct - I'm referring to modes like "stadium" and "adventure". I was SHOCKED to discover that these modes mess with the bass response big time. For instance, when using the Adventure mode, it actually sends a significant amount of bass to the fronts which are above the xo point, even though they are set to Small speakers . IIRC using this mode gave me a big hump at 40-60hz with the xo set to 80hz.

In playing around with the modes, I found that only the "Straight" mode gave me a normal curve as far as what bass was being sent to the fronts.



> I would expect Stereo/DPL/DD/DTS to all be flat from input to output, but like I said, the other modes are going to play with reverb, delay, frequency response, etc. to "create" the acoustical environment they're imitating.


Right. I feel kinda bad about running in straight mode because I think a little of those types of effects can add some ambiance and liven up the sound a bit. However doing so we messing up the bass and I couldn't compensate with that with filters without using Straight.



> If your observations are based on a speaker measurement, you could also be getting output from more the the left main & sub (assuming you're using the left input channel), depending on the mode selected. To create the desired ambiance, the effect mode may send a little signal to the same side surround, center, or even the right channel.
> -Brent


With Adventure mode when I measured I only had the L/R fronts connected and the sub. The response curve had a terrible hump at 40-60hz IIRC. I disconnected the sub and remeasured and the hump was still there, and my xo was at 80 hz! Then I changed it to Straight mode and remeasured. The hump was then gone, and I was then able to use REW to set my house curve and fine tune the response accordingly quite nice. With Adventure mode engaged it was a loss cause.

And, although Adventure mode was the worst, all the other modes did something to mess up the bass to. It was only the Straight that kept things workable to obtain the proper curve.

And yes, just to confirm, the Straight mode still applies tone control and YPAO and such. The mode that bypasses everything is referred to as Pure on the Yamaha which I am not using. Also IIRC there was little or no difference in my measurements in Pure vs. Straight mode.

The bottom line is that I really would like a way to use some of these modes without having to sacrifice good base as a result. Just give me a little reverb or delay or whatever the effect is without screwing up the base. Hummm. I just dawned on me... I think Yamaha allows you to create your own modes - so maybe I could start with Straight and add in a few of the reverb affects... ? Have to play with that I guess.


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## brent_s (Feb 26, 2007)

The modes aren't actually altering your bass management settings. In stereo mode, BM has a flat signal to work with, thus your measured room response resembles the ideal target curve in REQ. Now, throw something like "club" at that signal and the Yamaha probably applies at least a couple of dB's of boost somewhere between 60-100hz (maybe even that whole range or varying boosts at different frequencies) to give you that dance club "thump". Now, you're BM is working with a boosted signal around it's xover point...thus your in room measurements will look different, even with the same mic position and volume setting. You could probably create a similar effect in "stereo" by doing an A/B test with the bass tone control maxed and flat. In trying to EQ an effect mode flat, you're defeating the purpose of the mode, IMO. The boosted bass is part of the effect Yamaha is trying to achieve. 

In a nutshell, your receiver is working as designed. Yamaha's DSP soundfields are among the best offered, but I think very few people end up using them on a regular basis. Other mfg modes are likely to apply similar processing to the signal. 

My first surround receiver around '93 or so was a Yamaha RX-V850, DPL only...I experimented with the sound fields some, but ultimately preferred native processing, even with the DSP effects dialed way down. I've had my current preamp for 8+ years and probably haven't totaled more than 5 minutes in the non-native modes for a particular source. From what I've read, IIx Music/Movie are the best option for adding some surround effect without getting too gimicky...YMMV. My living room receiver, a Pioneer 516 has IIx and I leave it set for Movie on non-DD/DTS signals and it seems to work pretty well for stereo only music sources. 

Actually, if the only thing that changes is your receiver, your BFD curve is likely to not change. You're EQing for in room frequency response which is a function of the speaker placement, speaker frequency response, and room shape/size/contents. A high quality receiver such as the 1800/3800, really any modern receiver, should just be a straight wire with gain and not futz with the signal. That's also assuming, of course, that the YPAO in the 1800/3800 doesn't behave differently than the 6090...chances are Yamaha's made a few advances between generations so your BFD may require some minor tweaking to taste once the newer YPAO does its thing.

-Brent


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## jerome (Apr 24, 2007)

lovingdvd said:


> Anyone use REW to measure Yamaha RX-V1800 or RX-V3800?
> 
> At any rate, I just purchased the Yamaha RX-V1800 and it should be here shortly. I am VERY CURIOUS to know if I can use some of the basic processing modes in this receiver such as THX Cinema etc without having it screw with the bass like my Yamaha 6090 did.
> 
> Has anyone done any measurements with REW and noted what impact the various modes of the 1800 or 3800 have on the bass? Might I finally be able to use these modes without it messing up my bass?


I just received my RX-V1800 yesterday. I haven't performed any REW measurements yet but are you still interested in seeing the differences between the processing modes ?


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