# Running REW for speakers



## gperkins_1973 (Aug 25, 2008)

Hi there,

I sorted out my sub no probs with REW but when I set my speakers to 75db in check levels which is fine and adjust my input level to -18db I am only getting a 27db measurement on my graph.

Anyone help please. :help:

cheers

Graham


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## gperkins_1973 (Aug 25, 2008)

Here's a picture of what I am getting. Please help asap! :scratch:

cheers
Graham


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## Moonfly (Aug 1, 2008)

Does the graph tally up with what the SPL meter shows itself? It really looks like your subs raised levels are having the effect of raising your crossover point. Your speakers look fine over 150hz, and given the boosts you have applied to your sub thats exactly were you would expect the crossover to end up.


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## gperkins_1973 (Aug 25, 2008)

Dan,

The spl meter reaches up to 82db. I have never had this before. It has always been fine.

Any ideas what would normally cause that to happen.


cheers
graham


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## gperkins_1973 (Aug 25, 2008)

Dan,

The BFD and Behringer are off so the only signal going through is the two speakers.

So REW should only be reading the speakers shouldn't it.

cheers
Graham


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## gperkins_1973 (Aug 25, 2008)

Dan,

Still a bit confused, shouldn't REW only measure what is connected at the time. My REW sub graph shows it tailing off. Does this mean that REW is not accurately measuring. Surely if I only have two speakers connected set to 75db then it should only measure them two with the crossover set to 80hz. The sub isn't even in the equation at the moment so in theory REW doesn't even know that the sub exists.

cheers

Graham


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## brucek (Apr 11, 2006)

> Here's a picture of what I am getting. Please help asap


I don't see the problem? Explain.

brucek


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## Moonfly (Aug 1, 2008)

If your measuring only the speakers, ensure your using the speaker test tone.


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## gperkins_1973 (Aug 25, 2008)

Hi Guys,

Attached is another picture show what db the measurement is. It is showing 31.2db yet the target is supposed to be 75db so my graph is way too low. But my problem is I am measuring using the speaker tone to get 75db which is fine and then I adjust the input level to -18db which is fine. I then do a measurement and that is ok and then I only get 31.2db which can't be right. So when I lay my sub and speaker graph together the levels are all wrong. 

I hope I have explained it ok.

cheers
graham


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## Moonfly (Aug 1, 2008)

brucek said:


> I don't see the problem? Explain.
> 
> brucek


I think he is wandering why his speaker levels appear low. His sub shows reference level with the amps volume at -28. It would seem the is a 10db or so discrepancy, but that could be down to him running his sub hot, not sure :scratch:


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## gperkins_1973 (Aug 25, 2008)

Dan,
The sub amp is set to 28db on the gain (advised by behringer) but my sub is calibrated to just under 80db on the spl meter running test tones through the onkyo hence my sub trim level is -9db.

Hope that clears that up.

cheers
graham


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## gperkins_1973 (Aug 25, 2008)

Dan,

I just ran some sine wave test sounds to the speakers and 60,80,100 and 120 hz all came out at 75db and 140 came out higher, probably due to a peak. 

wierd

cheers

Graham


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## brucek (Apr 11, 2006)

> It is showing 31.2db yet the target


Do you mean the 31.2 dB showing beside the measurement checkbox below the graph? 

That indicates the level of the signal where the cursor meets the measurement trace. Move the cursor around and watch the level change... It's a convenience for you to get a readout anywhere on the measurement.

I overlayed the speaker crossover target on your graph (which you should be using rather than the sub target). It looks kinda perfect to me other than you have a dip at 85Hz.









brucek


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## Moonfly (Aug 1, 2008)

Yup, graph is as expected really. Brucek is pretty much the final word guy on here too, and I certainly cant put things better than him, his illustrations are top notch :T


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## gperkins_1973 (Aug 25, 2008)

Bruce,


Here are some measurements taken of the speakers with crossover settings from 40hz to 100hz. Top line being 40hz and then downwards. The other line is my sub. It looks like it is crossover over at about 95hz. 
My speakers don't look like they have changed all be it slightly higher each time. 

cheers


Graham


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## Moonfly (Aug 1, 2008)

The speaker response is exactly as it should be. What is it you think is wrong here?


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## gperkins_1973 (Aug 25, 2008)

Dan,

I am just curious as it looks like I have a large dip between 80 and 100hz on my speakers which would mean I am missing information between those frequencies going through them. My crossover on my sub is set to 80hz. Should I just change it to 100hz so that missing information on my speakers is going through my sub. And then should I change my crossover on my speakers to 100hz too or leave that at 80hz.

Please tell me if I am looking at this all wrong.

cheers
graham


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## gperkins_1973 (Aug 25, 2008)

dan

Just had a thought. Have a look at my graph of my sub and speakers. If I raise the 80 to 120hz region on my sub so that it is flat and set my crossover to 120 on my sub it would then meet the level of the speakers at that frequency.

Would that work?

cheers

Graham


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## Moonfly (Aug 1, 2008)

Your dip is between 80 and 120 hz, but is only 8db at its deepest point. If its bothering you you could play with your crossover a little. Perhaps upping your sub 10hz and dropping you speakers 10 hz to give you a 20hz overlap. In all honesty though, if you cant tell when you try it then I'd leave things as they are. You have probably seen it said before that starting this whole REW and EQ process can be like opening Pandoras box, and it seems to me you may just be bordering on that point. You have to be ready for the point when you have pretty much reached your goal, and then let it go, or you'll never stop chasing perfection.

Perfection is impossible :T


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## gperkins_1973 (Aug 25, 2008)

Dan,

I also think that the sound coming from my front speakers could be fuller especially my centre speaker. 

I will run some graphs of that to see what is going on. Wierd thing is I have just re connected my speakers and I am now getting 70db on my measurement where I was getting only 31db before. Work that one out.


cheers

Graham


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## JohnM (Apr 11, 2006)

gperkins_1973 said:


> Wierd thing is I have just re connected my speakers and I am now getting 70db on my measurement where I was getting only 31db before. Work that one out.


You may have missed BruceK's post on that - the number shown at the bottom of the graph is the level at the frequency the cursor (blue line) is set to. When you were seeing 31.2dB the cursor was at 10Hz.


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## Moonfly (Aug 1, 2008)

Dropping the frequency limit on your speakers will probably help fill them out a bit. In all honesty it will probably cloud them a little too. These digitally processed systems do make HT great, but can have the effect you describe in my experience, at least with music anyway. John has addressed your other concern.

I reckon its just a matter of final tweaking to your taste now. At the end of the day thats what this is all about. Get your system as flat as possible so its as accurate as possible, then adjust to personal taste. Its almost time to step back, dust of your hands, and give yourself a pat on the back, as long as your happy anyway. Just be aware your new super sub might now be showing itself as being a cut above the rest of your system :devil:

Then its time to take all you have learned, and use it for the benefit of others on here :T


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## gperkins_1973 (Aug 25, 2008)

Hi guys,

I have attached a pic to show my sub, centre and my main speakers. Not sure if this tells you anything but if it does it would be good to know.

Centre is green and main speakers are red. Sub is blue

cheers

Graham


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## Moonfly (Aug 1, 2008)

It tells us everything is just fine :T, between them it looks like your mains and centre are creating a decent response together to add to the one your sub is showing.


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## gperkins_1973 (Aug 25, 2008)

Dan,

Cheers for that. Its good to get a second opinion just to make sure. So one more thing, with regards to mid bass slam I guess not all of that will be coming from the sub so you are relying on your speakers to help with that as well. I will play with lowering my crossover on the front 3 slightly and see how it goes.

cheers

Graham


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## glaufman (Nov 25, 2007)

Next step is to run the sweep with both the mains and sub playing, to make sure they play nicely with each other.


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## gperkins_1973 (Aug 25, 2008)

Greg,

I will do that tonight and post a graph.

cheers

Graham


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## hybris (Jan 25, 2009)

So, did you get around to measuring your sub and mains together? It's a great idea to measure them both separately to see which speakers do what - but you won't really know how your practical frequency response is before you measure it all together (as I assume you listen with both mains and sub turned on at the same time)


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## Moonfly (Aug 1, 2008)

hybris said:


> So, did you get around to measuring your sub and mains together? It's a great idea to measure them both separately to see which speakers do what - but you won't really know how your practical frequency response is before you measure it all together (as I assume you listen with both mains and sub turned on at the same time)


And dont forget, if your unlucky to get a phase issue, you can only see it with measurements done with both fronts and sub included together.


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