Home Theater Forum and Systems banner

worked with rew most of the day and got this?

2593 Views 23 Replies 2 Participants Last post by  mojogoes
Hi as above all day but couldn't seem to get anywhere ....


I started off with the correct graph aswell but as you can see the graph changed to this one after i made this measurement......and i couldn't change it back unless i came out of rew and re-set/deleted everything.

Could someone give me an insite to where i'm going wrong please.
1 - 20 of 24 Posts
That measurement is just the inverse of the calibration file you have loaded, which means it is measuring a direct loopback - either an external loopback connection you have left in place or an internal soundcard loopback caused by selecting "stereo mix" or "what u hear" or similar instead of the line input on the soundcard.
You are perfectly correct i had a loop back connected....
So after the sound card is calibrated do i need to disconnect the loop back connection.

Do i also not need the two (control out mix/volume control input mix/volume) checked either.
Disconnect at least the right channel loopback, you can leave the left loopback in place if you want REW to automatically correct for the soundcard response (need to select the box in the soundcard settings to enable that).

You don't need to check the options to control output volume unless you manually select the input and output devices (rather than just using default) and you want to have REW set the levels when it starts up rather than controlling them yourself via the soundcard mixer. On some soundcards REW doesn't have access to the volume controls because the driver doesn't make them available, and under Vista the mixer doesn't work the same way as under XP so there aren't the same capabilities available to REW. In those cases best to leave the devices as default and check levels when you start REW, otherwise it can be a useful convenience to check the boxes and have REW restore the required levels each time it starts.
Thanks for that John..........yeah i'm using a s/b live24 s/c laptop xp and i'm also using the ecm8000 measurement mic and a B mic800 preamp......would it be easier to use the spl meter in place of the B/mic although the mic being more accurate.

I've selected the s/b live24 s/c in the input devices and the same in output devices is this correct....My connect setup is as follows (sub only) sub is going into bfd and instead of being connected to my receiver its connected to the line out on the s/c (front speaker Chanel) via a 3.5mm to twin phono adapter.
Then the mic is connected to the preamp which is connected to the line in with said same adapter both as stated in rew......on the preamp there is only 1 jack plug output which i have connected one side of a 2 way (2 phone's and 2 jack plug connectors) red/black into the line in is this alright/ok.

Has the fact that i've kept the loopback on my major down fall which i only did because i thought thats so i could check the device box's and rew would automatically control all the volumes.....but it seems that was a wrong move.

I appoligise if all this does not make complete sense.
See less See more
It looks like much more reading is needed here!!!!
Sounds basically OK, but you are generally better connecting through your receiver rather than directly to the sub so that you can see the effect of the receiver's crossover and also check integration between the sub and the mains.
Then afterwards when i need to load the filters do i return back to just the sub , or can i leave it as is and limit the frequancy range and then down/upload......
You can leave it as is, loading filters into the BFD or similar is independent of your measurement setup.
Gotcha cheers........i think i'll have another go tomorrow now as my boys are dew back soon and i don't want another bout of WHATS THAT! again!
I also see that your a Rel lover John....good man although i've just sold my stentor and am now trying out the bk monolith df with the bfd.....the rel stentor was a mk1 v and only had high level / 600oms connections fitted.
Hi i still don't seem to be getting anywhere....if i have the loopback connected thats all that seems like is beine measured and if i take the loopback connection off an imformation box appears saying my level is to low....could someone please tell me where i'm going wrong.
Which input channel (left or right) have you connected your mic preamp to and is that the same input channel you have selected in the REW soundcard settings?
Which input channel (left or right) have you connected your mic preamp to and is that the same input channel you have selected in the REW soundcard settings?

This is my last graph i just made....i will ave to cjust check which chanel i'm using now
Supposedly the right hand chanel

Box comes up stating i'm -48db to low!

Also bfd is in bypass mode is this correct....i can't seem to find what i'm doing wrong....could it be thati've got 2 3.5mm adapters straight into line and line out/front speaker etc.
With out the looback in place there seems no way inwhch i can increase the db output..

here is another graph taken with the loopback disconected and as you can see its much too low and doesn't meet target levels.......it was also done on the left chanel with said box checked.

If you get good signal with your loopback connected but not with your mic and preamp connected then the problem must lie with the mic and preamp. Is the preamp's phantom power output turned on? The mic doesn't work without phantom power. To get the mic working you can just plug the preamp output into an input on your system and work with the settings until you can hear yourself through the speakers (beware of feedback though! Be ready to mute your speakers).

Edit: you can also plug in your SPL meter in place of the preamp and see how you get on with that.
Phantom power is on and i've just connected the mic via the preamp output as you have suggested and got no sound

The preamp is the behringer mic800 mini moderling preamp...it has a vtc light that is always lit plus input 20db pad etc i will add some pic's of it shortly.

My preamp..


You would want VTC off (adds distortion to make it sound like a tube preamp), input pad off (reduces input sensitivity), preamp model 1 - Neutral (all other preamp model settings alter the frequency response). Adjust input gain so that the signal LED lights but the clip LED doesn't when you talk into the mic and adjust output gain so that the output VU meter is reading about mid scale when you talk into the mic. That amp also has a low cut (unfortunately) which you will need to turn to its minimum, but that still means it will be rolling off below 15Hz.
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.