My first graph!Whatta Mess!

**jdeanmc** · **12-31-08, 01:23 AM**

well here is my first graph using rew.assuming i calibrated everything properly.
My room is 23x23x8.
Hsu Vtf Mk3 Ho with turbo and mbm12,Ho is front left of tv.mbm12 is behind sofa slightly to the right.
Crossover in receiver is set to 80 hz.HO xover is set at about 48 hz xover in.mbm xover at 80 hz with xover out.both connected via y cable adapter to sub out to yamaha rx-v1800.
I have 2 bass traps on rear wall,hope to add more soon.
What can i do to improve response,and what about waynes hous curve?i am intriqued by this?
sorry i dont know how i lost key,light green subs only.blue subs and right front,purple subs and left front.dark green both subs and both mains.

**brucek** · **12-31-08, 08:28 AM**

Looks like the cross between the MBM and main sub is incorrect, or the phase between the two is canceling........

Test each individually and see what they look like.

brucek

**weverb** · **12-31-08, 08:52 AM**

Try removing the turbo and try the HO in max output and max extension modes. Looks like you may be better off without the turbo and in max output mode to help that major sag.

**jdeanmc** · **12-31-08, 10:03 AM**

Thanks, I will try each sub separately,then with turbo removed.
I was going to test each sub last night but it was getting late by the time i got everything up and running,i just wanted to make sure i could post a graph before bedtime.
Ultimately i want to be able to take full range measurements (i know,new spl meter)and add the bfd.
I downloaded the .cal file for my meter, loaded that and ran the loopback test thing with the right channels connected,should i have done one or the other?
Btw,between you two and Sonny and Wayne,(and all others on this bpard)i have high hopes that i can actually get my system up to snuff!Why on earth you guys offer all this help without ever asking for credit card info is beyond me

and no im not supplying credit card info.

**brucek** · **12-31-08, 10:20 AM**

Quote:

should i have done one or the other?

The left channel is never used. You only use the right channel.

brucek

**jdeanmc** · **12-31-08, 10:37 AM**

I mean should i have loaded the .cal file or done the loopback test to calibrate instead of both procedures.
The diagram shows hooking up the left channels for loopback test only but another post said use the right channels for loopback.Then connect to spl meter and avr.

**weverb** · **12-31-08, 10:46 AM**

Quote:

jdeanmc wrote:

I mean should i have loaded the .cal file or done the loopback test to calibrate instead of both procedures.

You need to do both for measuring. The cal file is for correcting the meter readings. You should have seen a very flat line when you did the loopback. Try posting your loopback graph so brucek can verify it is correct.

Here is my example:
http://www.hometheatershack.com/foru...tml#post117475

Quote:

jdeanmc wrote:

The diagram shows hooking up the left channels for loopback test only but another post said use the right channels for loopback.Then connect to spl meter and avr.

You use both channels for the loopback and then disconnect the left for measuring. After you have done the loopback, you do not need to use the left any more. It just stays disconnected.

**jdeanmc** · **12-31-08, 11:01 AM**

You use both channels for the loopback and then disconnect the left for measuring. After you have done the loopback, you do not need to use the left any more. It just stays disconnected.[/QUOTE]

Quote:

brucek wrote:

The left channel is never used. You only use the right channel.

brucek

I only hooked up the right and did the loopback.i never connected the left channels to anything

**brucek** · **12-31-08, 11:22 AM**

Quote:

I mean should i have loaded the .cal file or done the loopback test to calibrate instead of both procedures.
The diagram shows hooking up the left channels for loopback test only but another post said use the right channels for loopback.

I gotta tell ya, I rue the day that the optional ability to use the left channel for calibration was added to REW. It causes nothing but confusion, while adding very little to its capabilities.

Here's the deal.

Initially REW only used the soundcard calibration file method to compensate for soundcard response imperfection.
This method allows you to choose either the left or right channel to use for measuring. Only one channel is allowed. Once the channel is selected, a loopback cable is attached to that channel and the soundcard cal file is created and saved. Then before removing, to prove its effectiveness, a measurement is taken of that channel and the result should obviously be flat (since the saved soundcard cal file is in place). Then the loopback is removed and that channel is used exclusively for measuring. The other channel is never used.
This method is still the best and preferred method to use.

An alternate optional method was added that didn't use a soundcard calibration routine, but rather used a permanently installed loopback on the left channel, with the right channel used for measuring. The left channel would provide the calibration data on a dynamic basis. You needed to check a box to use this method. It added the feature to allow you to measure real speaker distances.

Unfortunately this newer "Use Left channel as calibration reference" causes more confusion than it should. I don't recommend it because it increases noise and slows the computer somewhat.

Straight?

brucek

**jdeanmc** · **12-31-08, 11:36 AM**

Straight as an arrow,So i did this correctly?How'd that happen!!!
Thanks for the clarification.
The wife will probably call in the men with the padded van if i try to take any sub measurements tonight,but ill get back on it maybe tomorrow night and post just the ho and then just the mbm measurements.
I hope to get the galaxy 140 spl soon,what bfd do i need if i want to control the system full range?

**weverb** · **12-31-08, 11:39 AM**

Quote:

jdeanmc wrote:

I hope to get the galaxy 140 spl soon,what bfd do i need if i want to control the system full range?

The bfd (DSP1124P) should only be used on subs. Not mains. You can try it on the mains, but it is very likely to introduce noise.

**Wayne A. Pflughaupt** · **12-31-08, 11:42 AM**

Quote:

jdeanmc wrote:

Why on earth you guys offer all this help without ever asking for credit card info is beyond me

and no im not supplying credit card info.

Well, we do accept donations!

Regards,
Wayne

**jdeanmc** · **12-31-08, 11:52 AM**

There you are!!
I will take care of that!
I do need your help with this hard knee house curve business when i start getting this mess straightened out

**Wayne A. Pflughaupt** · **12-31-08, 11:54 AM**

Quote:

jdeanmc wrote:

what bfd do i need if i want to control the system full range?

You might want to first take measurements of the main speakers to see if you even need full range equalization, before you jump off and start buying gear.

Full-range equalization can be a pricey proposition, because it requires an equalizer for each channel you wish to EQ (that would be a minimum of two additional units, even if you only want to EQ the front three channels). In addition, outboard amplification is typically required as well, unless you already have separates.

Regards,
Wayne

**weverb** · **12-31-08, 12:02 PM**

Quote:

Wayne A. Pflughaupt wrote:

Full-range equalization can be a pricey proposition....

Wayne was kind enough to warn me about this up front. It did not stop me from sourcing three Yamaha YDP2006's. Santa brought the third for X-mas.

**jdeanmc** · **12-31-08, 12:09 PM**

Well that does sound like more than i want to get into.I do however love to buy gear

I have lots of things i dont know how to use.
Anyway,that does sound reasonable.I will still need the galaxy 140 to measure full range will i not?
At this point my priority ,i guess is to get the equipment i already have as well as my horrible room, setup as best as i can via placement ,settings and maybe bass traps.
Thats why im taken by a thread i read of yours about the house curve and the difference it made in the overall fullness of sound.I was convinced that i needed another Vtf ho because of room size but now im thinking that there is alot of potential left in what i already have.

**Wayne A. Pflughaupt** · **12-31-08, 12:15 PM**

Quote:

jdeanmc wrote:

I will still need the galaxy 140 to measure full range will i not?

Yup. Even if you don't equalize the mains, it's never bad to know what you have. Often simple placement adjustments can make a difference...

Regards,
Wayne

**jdeanmc** · **12-31-08, 12:18 PM**

Well great,now i want those!!I am a big fan of Yamaha products,My Avr is the Yamaha Rx-v1800 and i do make my living with Yamaha M/C ATV and Pwc's

**weverb** · **12-31-08, 03:13 PM**

Yea, the YDP's are great. Wayne pointed me in their direction and they have worked out great. They are just as easy as the bfd to use and have a cleaner sound and are well built. They make the bfd feel like a piece of tin foil compared to these.

**jdeanmc** · **01-01-09, 08:09 PM**

O.K here we go again.
1st graph Ho Only
2nd graph Mbm12 only
3rd graph both subs on with Ho phase set to 0
4th Graph both subs on with Ho phase set to 180
5th graph soundcard calibration file

**weverb** · **01-01-09, 08:15 PM**

Need to see the sound card graph at full range (0-20,000Hz).

Is the HO in ME or MO mode?

**jdeanmc** · **01-01-09, 08:22 PM**

the ho is in max ext.with turbo on.

**weverb** · **01-01-09, 08:26 PM**

Sound card graph looks great.

Switch the HO to max output and remove the turbo.

**jdeanmc** · **01-01-09, 08:28 PM**

ill do that and have a new graph momentarily.

**jdeanmc** · **01-01-09, 08:37 PM**

sorry fist graph was with mains.second graph is Ho only

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