# my new in room response



## acoustat6 (Mar 7, 2008)

Hello all, It has been a while since I have last posted. I obtained a calibrated EMM mic from Cross Spectrum labs. Thanks Herb for doing this valuable service, and dont forget Herb was great to do business with.

After checking results from my previous Radio Shack SPL meter measurements I found the RS meter to read 2-3 db low in the very low freq, though it appeared accurate for the freq response, ie: it read low but the response was close. I also can confirme it should not be used above 3-4k hz.

So here are a couple of graphs in the following posts.

First graph is 10 to 100 hz no smoothing.



Continue in next post.

Bob
PHP 143


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## acoustat6 (Mar 7, 2008)

Next is 10 to 20000hz no smoothing.

Bob


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## acoustat6 (Mar 7, 2008)

10 to 1000hz no smoothing

Bob


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## acoustat6 (Mar 7, 2008)

20 to 200hz waterfall

Bob


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## porksoda (Feb 25, 2010)

what equipment was used... sub/fronts/amp/avr.

Also both mains or just single main channel and sub?


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## glaufman (Nov 25, 2007)

It's nice to keep he same scale on the waterfall as the sweep it was made from.


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## Nuance (Nov 2, 2008)

How about applying 1/3 octave smoothing to the full range sweep (10-20,000)?


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## acoustat6 (Mar 7, 2008)

Hello, this is full system all speakers... subs, mains and tweeters as in the picture attached.
Attched is 20 to 20k with 1/3 octave smoothing.

I would like to bring up the midrange at some point. I love REW!

Lots o' bass traps.

Bob


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## Nuance (Nov 2, 2008)

Thanks for posting with smoothing. 

When you measured, did you measure each speaker one at a time, then average the measurement? This will give you a more accurate reading of what you're actually hearing above the crossover. Do not measure both speakers at the same time (you can leave the sub(s) on while measure each individually).


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## acoustat6 (Mar 7, 2008)

Hi Nuance, this is the full system in stereo freq response. 

Also I did not mention the use of a Behringer EQ for the bass :bigsmile:. and a Marchand Bassis for the bass also :T. That is correct I have two EQs to control the bass! Actually make that three EQs as we cant forget that I listen to vinyl and its phono pre amp EQ. So three EQs for bass control in room, hows that for anti audiophile!:rofl2:

Actually, I find that its as audiophile as it gets. I believe that one of the basic tenets of Hi Fi is a great in room response and that appears impossible to obtain without EQ. To me the non use of an EQ is anti audiophile :yikes:

I am not sure why EQ is such a dirty word in audio land. Though my guess would be because we all tried them in the good old days, you know, you bought an EQ, hooked it up and then started twiddling the dials by "ear". Could it be any wonder they sounded "bad". As I am sure that folks here have discovered its about precision. And you cant do it by ear.:rant:

Attached is a picture of the back of my listeng room with all of the diffusion in place :bigsmile:. The graph, while not current, shows the effect of my 20hz filter (on and off) for use with vinyl.

I also would like to say a big thank you to the folks who created the program and allow us the use of this fine program for free:T :clap:

Bob
PHP143
If the first 100db suck, why continue?


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## acoustat6 (Mar 7, 2008)

OOPS The picture I was going to post is too large, sorry.
So now for something completly different two pictures of the 1977 Laverda 1000cc V6 endurance racer. The man in orange is Mr Laverda himself. Pictures taken in 2008 at Mid Ohio race course. Hope its not TOOOO off topic. 
Bob


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## acoustat6 (Mar 7, 2008)

Hello, 20-100hz waterfall with 45-105db scale.

Bob


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## Nuance (Nov 2, 2008)

acoustat6,

I think EQ only becomes a dirty word to some when you use it above the Schroeder Frequency. EQing the bass is a must IMO.

Three EQ's? Wow...dunno if I would do that, but its your system. 

So can you re-take measurements, measuring one speaker at a time (just unplug one if necessary)? You can overlay them under the "measured" tab, or average them under the "average" tab. Then post them here again. I suspect the measurements will look better, perhaps being flatter in the HF's.


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## acoustat6 (Mar 7, 2008)

Hi Nuance I will do that, I have tomorrow off from work, I will try to do individual speakers tomorrow.

bob


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## acoustat6 (Mar 7, 2008)

Hi Nuance, I did some measurements on Tuesday and as I was unplugging the mic after the tests I inadvertantly pulled the plug on my laptop (no battery backup). I redid some testing on Wednesday and will post graphs as soon as I can transfer them to my main computer. I did bring up the midrange and the graphs look superb.

Nuance can you post or point me in the right direction to some of your graphs?

Some more off topic orange motorcycle pictures. My 1974 Laverda 750SFC endurance racer and 1977 Guzzi LeMans 1. Some hippies checking out an SFC back in the day.
Thanks,
Bob


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## Nuance (Nov 2, 2008)

acoustat6 said:


> Nuance can you post or point me in the right direction to some of your graphs?


Sure.

These measurements aren't the newest, but here is the best I could do in my room. This measurement is of the two speakers measured from my listening position, averaged (200Hz-20,000Hz):










This is a measurement of my subwoofers from 15-200Hz:










These are my buddy's Revel F32's. Notice there are two measurements, each being one speaker measured individually and then overlayed under the "measured" tab in REW:










Here is the same Revel F32's waterfall plots after my friend added bass traps to the corners:

Before bass traps









After bass traps









Anyway, you get the idea. I hope that helps, and I look forward to your measurements.


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## acoustat6 (Mar 7, 2008)

Hi Nuance Ok here we go. It takes me some time to do this as I have to use a floppy disc from my laptop to my main computer to transfer the mdat.

First graph shows 10 to 200hz no smoothing with the 20 hz filter on and off. Yea I have extension:yikes: My house curve is, at this time, 30 15, 100 0.

I did up the midrange so the response is better than the previous one:clap:

next is 10 to 20000hz no smoothing

next is 10 to 20000hz 1/3 smooth

next is 10 to 20000hz 1/1 smooth

Thats all for now. I will post the individual drivers subs, mids and tweeters soon.

To do this so everyone is using the same graphs, are there a few standard graphs with freq vs smoothing ranges? IE: 10 to 200 with/ without 10 to 20000 with/without smoothing etc. so we can all post the same meaningful graphs?

Your waterfalls are from 100 to 500 aren't waterfalls supposed to be low freq 10- 100hz and RT 60 100hz up?
Bob
PHP143


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## acoustat6 (Mar 7, 2008)

As I mentioned in my last post looking for standard graphs so everyone is on the same playing field. I generally use 10 to 450 hz and 450 to 20000hz for two different views of full range. This splits the full freq range in "half". On the screen 10 -450 then 450 -20000 fits nicely for two graphs showing low freq and high freq within the two graphs.

Are there freq ranges that are standard for posting graphs?

Just in case you wanted to see my sub sysem, it is 32 eight inch drivers in a stereo pair sealed enclosure with each speaker using 8 forward and 8 rear facing drivers. pictures attached of the building process.

Another Laverda my 1982 RGS Corsa 1000cc triple. Not all Laverdas are orange.
Bob


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## glaufman (Nov 25, 2007)

We generally do 10 or 15-200Hz for bass, and 10 or 15 -20kHz for full range.


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## Nuance (Nov 2, 2008)

acoustat6,

So are the speaker measurements graphs taken from 10-20,000Hz an average of both the left and the right speaker measured individually, or did you just measure will both speakers plugged in at the same time?


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## acoustat6 (Mar 7, 2008)

Hi Nuance, Thanks for the post, I assume the graphs are 1/3 octave smooth. Would you be so kind to post a graph with one octave smoothing?

I see you do not use a house curve in your graphs, have you tried one?

I enjoy my house curve. :bigsmile: I just recently extended it out further to 100hz from the previous 60. I had read someone recommend it and tried it. It gives a smoother bass and while the jury is still out I would recommend it to others. I will let you know if I change it. I am not so sure if I would recommend the +15db at 20hz but it sure sounds good in my room. :T When listening to vinly the 20hz filter is employed.

Compare it to the first graph, even with the 20hz filter on I the speakers are "flat" to less than 10hz. 

I like to look at graphs several ways (obviously), I found a nice way to see the graphs with good resoluion is with with graphs from 10 to 450hz and 450-20000hz. This way you also see intergration among the different speakers more easily. These are with one octave smoothing.

I am working on posting the individual speakers, so hold tight.

Also I would like to make one comment and that is, and maybe this is an understated fact, is that every time my systems freq response is "improved" and I mean improved in several ways ie smoother or with a better house curve it makes me realise I have just touched the tip of the icberg with this and that the capabilites with my system are endless. Especially as I also realise that I am just learning to use REW and tuning my system. This is where I will be spending my resources, time and energy. This includes all freq.
The magic is in the FULLRANGE.

Bob

PHP143


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## Nuance (Nov 2, 2008)

acoustat6,

I applied 1/3 octave smoothing to my graphs. I also used the forum standard of 15-200Hz for bass response, then 200-20,000Hz for the rest. 

I have tried a house curve and liked it for movies but not for (all) music. For some reason my receiver applies a bit of what seems to be its own house curve, so it naturally rises up (slightly) start at 80Hz or so. Its perfect for the HT experience in my room, IMO. Here is a pic of the response:










Oh, and I crossover to the subwoofers at 80Hz, for what its worth. 

REW is certainly an amazing tool, and also made me realize I had only touched the "tip of the iceberg" when I first began using it. Since then I have re-positioned my speakers, subs and added room treatments. The difference was a better over sound (Objective and Subjective); there was nothing subtle about it. My room is rather small and my speakers are closer to the room boundaries than I prefer (2-3 feet), but all things considered I am very happy with how it sounds and measures. Off-axis I hardly loose any linearity in the frequency response. :bigsmile: I do look forward to setting my system up in a nicer space, however. One day...


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## acoustat6 (Mar 7, 2008)

Hello, a few graphs of the subs only. I have applied my current house curve.

All of my graphs are taken from two speakers running at the same time.

First is subs only, one octave smoothing

Second is subs, only no smoothing.

Third is waterfall.

I am off to work, get back to you soon.

Bob


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## acoustat6 (Mar 7, 2008)

Hi Nuance, I have been using REW for awhile. The revised interest in the posting is due to the new calibrated EMM6. The increased resolution was well worth the price of admission. 

I was able to intergrate my 3 way system speakers much better and I continue to find that whenever I get a better response, well, my system sounds better ( how come there is no little smile man jumping up and down with joy). The ability to correleate the sound with the graph, is eye and ear opening. And really the thought that if I had to live with adjusting my system by ear gives me nightmares. 

My other obsession is motorcycles. I do hope you don't mind me posting my bikes, it give me pleasure and I do hope you enjoy looking at them. There has got to be a few gear heads here! Here is my 1965 MV Agusta 125 GTL.


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## acoustat6 (Mar 7, 2008)

OOPS in my last post I wrote " I do hope you don't mind me posting my bikes, it give me pleasure and I do hope you enjoy looking at them. "

That is a collective you, nobody in particular.
Bob


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## acoustat6 (Mar 7, 2008)

Hello, Here is a freq response of the Acoustat 6,both speakers which have crossover points of 80hz and 1700hz. This graph is with 1/3 smoothing. 

The Acoustats are driven with a pair of the direct drive tube amps. I am currently using a Behringer 3 way crossover. If you are in the need of an inexpensive crosssover this fits the bill. It sounds and performs great.

Pictures of the Acoustat amps. Oh, and a messy room:bigsmile:

BUT I can't wait to have my Marchand XM126 upgraded to a 3 way. 

Bob
PHP143


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## acoustat6 (Mar 7, 2008)

Hi, Here is a graph of 10 to 45ohz with one octave smoothing. It shows the crossover point at 115hz, which according to the Behringer crossovers not so calibrated dial, it should be 80hz. One of the compelling reasons for the Marchand crossover

Green line is subs with 20hz filter on.

Blue line is acoustats.

Gold line is full range with 20 hz filter on .

The appropriatly named  Red line is full range with 20hz filter off! I do run a 20hz filter at all times when using vinyl. The filter is built into the Marchand Bassis.

All graphs with one octave smoothing.

Looks and sounds good to me but I have a few ideas with tweaking the freq response.

Bob


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## laser188139 (Sep 19, 2009)

acoustat6 said:


> ... It shows the crossover point at 115hz, which according to the Behringer crossovers not so calibrated dial, it should be 80hz. One of the compelling reasons for the Marchand crossover ...


Bob, I expect there is nothing inaccurate with the Behringer crossover. This is the natural effect of the boost you have in the sub range. Imagine your green sub curve were translated downward so that it was level with the blue main curve; the in-room crossover would then be very close to the electrical 80Hz crossover. You can verify this using the trace offset under the Trace Adjustments in REW to adjust the level of the sub curve.

Bill


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## acoustat6 (Mar 7, 2008)

Hi Laser, actually after I wrote that I thought about it and agree with you. I should not have blamed the Behringer. MY initial thought waas that the knobs are small and difficult to see adjust. But I agree it is either user error of some phenomna, I am sure the Behringer is accurate, the 2496 sure is!

Here is a response of the Bohlender neo 8s line source. These are crossed over at 1700hz though according to the measurement it appears to be 1500hz. Curretly driven by a SAE 2400 amp.

Also is Acoustat and Bohlender at crossover point.

and then one showing both crossover points

All with one octave smoothing

Bob


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## acoustat6 (Mar 7, 2008)

Hello everyone, here is a RT60 measurement. 

I have been trying to get a pair of Rane PE17s to work for my mains (Acoustat) but I get a buzz in the speakers. I have tried different grounding schemes but no change at all. Any suggestions?
Bob


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## acoustat6 (Mar 7, 2008)

Hello, 15 to 200hz all speakers, no smoothing.

Bob


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## laser188139 (Sep 19, 2009)

acoustat6 said:


> Hello everyone, here is a RT60 measurement.
> 
> I have been trying to get a pair of Rane PE17s to work for my mains (Acoustat) but I get a buzz in the speakers. I have tried different grounding schemes but no change at all. Any suggestions?
> Bob


You have tried the recommended ground schemes, eh? That's too bad because that is the obvious suggestion, looking at the PE17 manual. 

You could try using REW's RTA/Spectrum measurement to baseline the audio going into the PE17 and then look at the audio coming out of the PE17. It includes spectrum and RTA bandwidths down to 1/24 or 1/48. 

It looks like you posted an RTA graph of a sweep measurement. There is an option for finer resolution, down to 1/3 octave that might show you more. But the sweep signal itself may cover up your buzz. For background noise, the RTA/Spectrum view is a little more helpful. 

Bill


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## acoustat6 (Mar 7, 2008)

Hello, long time no post so here is an update. I bought a used Decware Torii mk2 tube amp at 25wpc for my Bohlender Graebner tweeter system. Unfortunatly it was shipped and damaged by UPS, they apparently feel the need to throw or drop things from a big distance and really dont care about your package. 

It is currently at my local techs shop for repair. 

Off topic picture is my 1977 Bimota SB2

Bob
PHP143


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## acoustat6 (Mar 7, 2008)

And another off topic picture of the Bimota

Bob
PHP143

Lets try that again, here is the picture.:sn:

Bob

Not quite sure why the oicture is not loading, oh well.:huh:

Bob


*Mod comment: posts merged, please try not to submit multiple consecutive posts. Cheers*


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## mksharma (Sep 11, 2010)

Very nice post, if you increase wave range more 3-4k hz, it would be fantastic........
______________
Real Estate Blog


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## acoustat6 (Mar 7, 2008)

Hi Mksharma, Thanks for the nice reply. You are correct, I still need to EQ mid range and high freq in certain areas. That is why I need more equalizers, one for the mids and one for the highs. I currently use a Behringer EQ for the subs which are crossed over at 85hz. I understand that they are not the most transparent EQ for high freq, though I should buy one and test it for myself::bigsmile:I am still looking for a good parametric eq that I can use on my Acoustats and another on the Bohlenders. I tried the Ranes but could not get a buzz out of them in my system. My ideal equalizer would be 3 to 5 bands (that would give me 6 to 10 bands for the freq range of 100 to 20,000hz among the two sets of mid and high speakers), parametric, cutting only and in a mono configuration (though I could live with a great stereo unit also), not asking for too much am I? :spend:


Bob,
PHP143
If the first 100db suck why continue?


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