Home Audio System vs HP sys
Aug 21, 2012 at 12:44 PM Post #16 of 33
I've decided to stay away from a speaker set-up at home until I build a new house - which will be built with a dedicated audio room and HT in mind from the start.


I've got that now. It's worth the wait.
 
Aug 22, 2012 at 1:15 AM Post #18 of 33
Is that a measurement of your speakers in YOUR room or some sort of unreal Anechoic chamber?

By the way, you definitely need a subwoofer with those.
 
Aug 22, 2012 at 10:44 AM Post #19 of 33
Quote:
Is that a measurement of your speakers in YOUR room or some sort of unreal Anechoic chamber?

 
So you're acknowledging that it's the room that needs the treatment, and not the speakers?  That looks like a Stereophile measurement, they do all their measurements in their own listening rooms at listening position I think.  Might be wrong however, as usually rooms bring forth more combing artifacts within the fr itself.
 
 
 
I do agree with you on the subwoofers though.
While the main speakers themselves need little alteration, subs are very hard to integrate.
 
Aug 22, 2012 at 12:49 PM Post #20 of 33
You equalize to correct for the way speakers sound in a room. Room treatments are fine, but all good speakers need EQ.

A measurement of how speakers perform in Stereophile's room or an anechoic chamer or in the White House is irrelevant. It's how they perform in your room that counts. I'm confident that no matter how good his speakers are, they aren't that flat in his living room.
 
Aug 22, 2012 at 7:25 PM Post #21 of 33
I have in-room response curves of my Infinity Renaissance 90 speakers, made with Room EQ Wizard, a Behringer UCA-202, and a Radio Shack digital SPL meter.  The vertical scale major lines are 5 dB apart.

With 1/3 octave smoothing:

 


The speakers are bi-amped, with an Adcom GFA-555 powering the woofers and a pair of Eico HF-12 mono amps powering the rest. They are only roughly level matched by ear.  I probably could have turned down the Eicos a couple dBs by comparison to the Adcom to flatten the crossover, but the 50 Hz peak can be overwhelming then.
 
When running the woofers and mids/tweeters off of the Adcom alone, the woofers play about 6 dB below the rest of the speaker - dropping off right around the 200 Hz crossover point.  I suspect the crossover caps need replacement, and I've been waiting for months for the caps I bought from Erse to be returned after I sent them back for measurement...
 
Similarly, I have the treble tone control on the Eicos turned down just a tad because of the 7 kHz peak.  I have yet to explore the possibilities of midrange to high frequency sound treatment in my room, which may solve the issue.  Parametric equalization would solve the peaks at both 50 Hz and 7 kHz, of course, but I have not had a chance to invest in that yet.  Given the two very specific peaks, I may be able to just create in-line filters to address them directly.  With proper filters and equal gain between the amps (or just a single amp for that matter, once I get the crossover refurbished), I think I will be able to get the 1/3 octave response within +/- 2 or even 1 dB from 200 Hz on up.

I believe the treble response is limited by the SPL meter's microphone, which is definitely unreliable above a few kHz (I have used common compensation curves for the meter, which make it quite accurate in the bass frequencies, but don't go up to the treble frequencies).
 
The bass unevenness, including the 50 Hz peak and 67 Hz null, is a result of in-room response.  The frequency response and waterfall graphs I'll post now are unsmoothened and compare my room with no treatment versus extensive bass trapping along wall-wall and wall-floor corners using blocks of blow-in cellulose insulation.

The cyan is the treated room, and the red is the untreated room.
 
a
 
 

 
 
Obviously there's still a long way to go in improving the sound as far as better rooms, better treatment, and equalization go, but reducing the nulls by 15 dB or so is quite a huge improvement.  The decay times are considerably better too, as evident in the waterfall plot comparison.  Even though the 50 Hz peak is not decreased at all, its resonance is.  The same goes for the 80 Hz peak, and the others as well.
 
The subjective results strongly correlate with the measurements.  With the bass trapping, the sound is immensely improved - the bass was boomy and very peaky without it, but tight and more even with it.

I should go as far as to say for the benefit of everyone here that equalization never will solve the issues of nulls in room frequency response - it can only reduce peaks, and it will only reduce decay time so much as you reduce the frequency range you are addressing.  As such, I do think that room treatment is even more critical than equalization, although I do agree that peaks are definitely more conspicuously audible than nulls.  So I would go so far as to say that equalization is fine and often desired, but all speakers need room treatment.
 
Aug 22, 2012 at 7:27 PM Post #22 of 33
Speaker placement can be critical. I have a pair of speakers wit best position at about 6 feet from the wall. The wife vetoed the placement.
 
My friend has the same issue with his wife. So he put down some duct tape to mark the position. Every time he listens to music he moved his speaker. In my case, I switched to a 2+1 system which allows a closer placement to the wall.
 
Aug 22, 2012 at 7:44 PM Post #23 of 33
Quote:
Speaker placement can be critical. I have a pair of speakers wit best position at about 6 feet from the wall. The wife vetoed the placement.
 
My friend has the same issue with his wife. So he put down some duct tape to mark the position. Every time he listens to music he moved his speaker. In my case, I switched to a 2+1 system which allows a closer placement to the wall.

 
Wait, the wife allowed duct tape on the floor but not the speakers?!?

Anyway, yes, it certainly makes a difference in the manner in which room modes and reflections are induced.
 
Aug 22, 2012 at 10:54 PM Post #24 of 33
Quote:
 
Wait, the wife allowed duct tape on the floor but not the speakers?!?

 
Aesthetically the duct tapes are worse, but they're 2D-flat for the most part. Imagine walking through a room with something expensive sticking out in the middle of it - that's like a wife/GF who just slips off her Christian Louboutins and leaves them in the middle of the hallway for the guy's Bass loafers  to squish.
 
Aug 23, 2012 at 12:39 AM Post #25 of 33
Equalization would make a huge improvement on that response. A tolerance of 1dB or less is best. However that bass dropoff is probably uncorrectable.
 
Aug 23, 2012 at 12:41 AM Post #26 of 33
Speaker placement can be critical. I have a pair of speakers wit best position at about 6 feet from the wall. The wife vetoed the placement.


Demand a man cave. It's every fella's God given right.
 
Aug 23, 2012 at 12:44 PM Post #28 of 33
Every house has a room that is totally wasted space... It's called the kitchen. All you really need in there is a refrigerator to hold the sandwiches and beer!
 
Aug 23, 2012 at 4:48 PM Post #29 of 33
Quote:
Every house has a room that is totally wasted space... It's called the kitchen. All you really need in there is a refrigerator to hold the sandwiches and beer!

 
 
Ahmen to that!
 
Aug 23, 2012 at 11:05 PM Post #30 of 33
Quote:
Every house has a room that is totally wasted space... It's called the kitchen. All you really need in there is a refrigerator to hold the sandwiches and beer!

 
If you can live without a kitchen you can't force a wife to live without one either. Even I can't live with just those. I'll need an indoor grill for steak, tuna and marlin; an oven for slow cooking tri-tip, brisket, pork shoulder and salmon indoors; a pressure fryer for chicken and calamari; a stove for sauteed broccoli, etc...not everyone gets to live in SoCal weather. Plus my mini-bar stocked with rum and brandy for drinking and for gravy.  
 
Damn, now I'm hungry  
beerchug.gif

 

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