Bartokfan
The measurement is from the "Thor"...-3db at 45hz would mean bass output (SPL) has dropped by around half at that freq. Most speaker systems are rated at their -3db points although how and where the measurements are taken is often not clearly stated.
The 12db figure...bass will be down in level by 12db at the next octave lower...a lot
Usable in room response means...some amount of sound that they deem "usable" will be output at those freq's. By saying in room, I guess they are saying that you will get some amount of bass help from the room....Maybe not in your huge room?
Dave |
Dave, from your explantion + the link I looked at earlier today, I finally get the idea of db level.
"with rolloff of 12db per octave BELOW 45hz" That is not much going on in the 45hz range when the amp is at lower volume, which is how I listen.
I think the "inroom usable bass" has something to do with the open baffel in the back, has a interesting baffel system, and so in a large room there will be less, smaller more. As you explain.
Thanks. |
Dave...
In your response to Bartokfan
>>>...-3db at 45hz would mean bass output (SPL) has dropped by around half at that freq<<<
Is there anyway to tell at what frequency the speakers output is flat? |
I have to agree with Mdhoover and some others who are arguing against the "greater frequency reposnse is necessarily better" viewpoint.
Quality reproduction in the 80 to to 12Khz range is more desirable than a speaker that is "flat" from 20 to 20 Khz but suffers from significantly more harmonic and IMD distortion.
Furthermore, an SPL meter and a test CD will give practically everyone who owns a speaker with a flat reponse from 20 to 20 KHZ a surprise....as most rooms have between 10 and 20 DB response fluctuations (peak to trough) below 80 HZ. This is unavoidable and is caused by standing waves....room treatments can help some but fundamentally some fairly big bumps will remain unless they are equalized out, and then, even equalized, the reverberation problem remains and any EQ'd flat response is limited to a small sweet spot.
A further problem of a speaker with flat extended LF response (no roll off) is that LF frequencies radiate in ALL directions...therefore they reflect off the rear wall and will boost by +6db at some frequencies and will cancel out a quarter wavelength from the wall (producing more frequency response bumps in addition to room modes)
Which all goes to show that flat frequency response down to 20 Hz may not necessarly be a good thing in a speaker. |
My experience with with sub 30 Hz in music is limited to just two audio systems, and our piano. When my wife is pounding out Grieg there is a lot more surfaces involved than the vibration of coiled wires.
I have a friend who is a conductor. I helped her find a house in Sacramento years ago. She had two requests. The house had to have a room big enough for her baby grand, and it had to have a wood floor.
If you want to hold a grand piano concert in your house, then you better have the real thing or speakers that can put out the power, and range of that piano. |
Muralman1, I agree, and then some.
The real thing is the only thing! No audio system will ever come close, not by a great margin, to ever reproducing the dynamics and power of a grand piano. Anyone who thinks otherwise hasn't been listening to much live piano music, in the home or concert halls. And it ain't just the sub 30's either. JMHO of course. :-) |
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Newbee, Don't be so sure. I have both. It was an Apogee Scintilla in a large stiff listening room that fooled me into believing I was listening to a pianist playing a grand. It did appear to be somewhere in the distance, as down the hall. I was awestruck. My present system takes my Scintillas to far beyond what was possible when they were made. It may be lunacy, but my goal is to duplicate the piano.
I wouldn't be the first. An Apogee enthusiast conductor use to give Mozart lectures at the Smithsonian's display containing the composer's piano. For fun, he would run a blind test on the audience. Alternating between the real deal and an Apogee Diva system. He asked the audience which they thought was real.
The Scintilla is even more convincing with the piano. |
Muralman1, I can't dispute what you've heard. Certainly I've not duplicated your experience. FWIW, and not a real comparison, but I'm sure you've heard a stereo system playing 'upstairs'. For those of us who have lived in flats or apartments/condo's etc, that would be common. Well when I lived in a flat in SF the upstairs unit had a grand piano - it never, ever, sounded like a stereo system. Especially transmitted thru the floor above. You knew what it was instantly - there is a whole lot of 'vibrations' going on with a live piano at all frequencies that just seem to elude (most?) audio systems abilities to reproduce with the same degree of dynamics as a live piano.
BTW I assume you meant by 'in the distance' that the sound seemed a bit compressed as compared to 'live' and that certainly would be one of my points of comparison. :-) |
My best friend just finished a feature film, and he was present when the Seattle Symphony recorded the score. In the church where they recorded, the composer and sound engineers set up a playback system identical to the one in the studio (which I heard on a recent trip to LA), so they could hear the recording immediately after each piece was played. Back and forth they went, live symphony to recorded symphony, for nearly a week. Very quickly, he said, the difference between live and recorded was so dramatic that the two sounded completely unrelated to one another, irrespective of whether they listened to the playback via the speakers or headphones. Didn't matter. Go to a studio and listen to the musicians play, and then listen to the recording. They are completely different events, always. Even the person at the helm has a huge effect on the resulting sound, so much so that we can recognize a recording produced by Daniel Lanois, or Butch Vig, for example. We might convince ourselves that a recording sounds 'so realistic', but it isn't. Never will be. A piano strike does not sound the same once passed through microphone, cord, processors, compression, gating, mixing, mastering, and the various components and cables that are assembled by nothing more than a personal preference. And we haven't even begun to consider the effects of comparing the recording space to the room where our system resides! Live and recorded, they are not even close to being the same, no matter how many times we attempt to convince ourselves that they are. |
Newbee, In the distance was all any amp could do in the 80s. The point is, the instant visualization was for a person playing a grand, although at some distance.
I hear you on the, "Lot of 'vibrations' going on with a live piano." That is the magic I am finding with the amps, preamps, and front end I am using. The sympathetic second, third an on harmonics, reverberations from the piano's surfaces, and nearby walls all add to the realness factor.
A next door neighbor asked me if I had a piano in the house, or could it be my stereo. I just answered yes.
Are you in the Bay area now? |
Hi Boa, how are you doing? You have a phone message.
There are no two piano makes that sound the same either. I have no idea what transposes in the studio, when I listen to a cut. There are recordings that are pretty darn good. I just have to be fooled, as you say, to feel sublimely satisfied.
I have one particular Royer ribbon microphone disc that, for sake of fidelity, does their best to minimize all the crap you list above.
I'm now in the process of trying new front ends. I hope you can find a bit of time to critique. |
I just have to be fooled, as you say, to feel sublimely satisfied. I ought be the first person to offer miles of leeway (sp?) for that one. I like to say that if our perspectives are delusional, why shouldn't they at least be fulfilling? Unfortunately, I'm not always so good at keeping the cynicism at bay. Thanks for the invite. We're in pretty heavy with our business stuff, but I may have time later in the week. |
Shadorne-
Your response concerning room anomalies provides specifics where I previously had only general awareness about these problems. 10 to 20 db is a lot of variation. When you say that room equalization is limited to a small sweet spot I wonder if you mean a pinpoint or a zone across the room being localized front to back.
I currently own a pair of speakers that reach down only to about 38 Hz. They are sold and I'm awaiting a new pair with deep bass capability that is equalized. After reading your comments I'm very curious to see whether or not I wasted a lot of money.
Does anyone here have equalized bass in their speakers and what have you found? Also what are your room dimensions? |
I think Shadorne is referring to equalization in the service of room correction. Which would apply as well to subwoofer equalization a la Velodyne or Vandy 5A. Do the Definitions have user-adjustable equalization? |
I have a friend who has subwoofers mated to ribbon speakers in a small, very irregular room. He uses TacT, where he can read all the frequency curves reaching the single seat sweet spot. There were big dips in the upper bass area. By some repositioning and equalizing through TacT he managed to straighten things out.
Now his play back is more than reasonably flat through 25Hz, with subwoofer in place. |
Dan,
The Definitions have internal amplification for the onboard subs. These have an adjustable gain control on the back of the cabinet. Zu also makes (but doesn't publicize) the Definition Pro which has heavier duty professional grade woofers and requires Bi-amplification. With this arrangement they sell you a RANE PEQ 55 digital parametric equalizer to tailor the response from 40 hz down to 16 hz. This is what I have on order. The difference in price between my old speakers and these new ones is such that I am looking for a big improvement. |
Macrojack
Room anomalies take place in all rooms, and with all speaker systems. The room and the speaker system are an equal partner and must be made to sing together...in harmony.
Room modes are "modal" or "non-modal" peaks and dips. Modal are room related and non-modal are speaker/seating related...ie, caused by speaker placement or seating placement in relation to room boundaries.
Modal...room treatments can help smooth these peaks and dips out a bit...a small amount of EQing can bring down some of the peaks even more. You can not EQ out a large dip (null) in freq response...move the speakers and or listening position a bit if non-modal...move around or add more room treatments as needed if the problem is modal....could be also a combo of both.
If your the conductor of a large orchestra trying to get all the sections to sing together...in harmony, and the bass instruments just won't cooperate for several reasons...Do you blame them and:
1. Get rid of them and declare the music sounds better without them anyway.
2. find out what the heck the problem is and come up with the fix.
I think some people go with #1
Dave |
Macrojack, FWIW, as I have no experience with Zu's, what Zu is offering is probably an excellent solution to providing really deep bass in a meaningful way. A parametric equalizer will go a long way towards solving speaker and room integration.
However (and you knew there was a however coming :-)) whether your room can support this type of bass is one issue and whether your sources/components can withstand the distortions that the additional sound pressure created by this kind of bass can produce is another.
A third issue to consider is that typically an equalizer can be very effective in lopping off the peaks of nodes but isn't nearly as effective in raising the level of the nulls to 'flat' without doing some damage to the sounds of the neighboring frequencies and soaking up a lot of the power available from the amp. That is usually determined by the design of the equalizer, the amount of correction needed and the power available from the amp.
Have you mapped out your room and determined its nodes and nulls and how they will effect the sound at the listening position and where the speakers will be positioned for best sonic results considering the upper frequencies which are determinitive of things like sound staging, balance, and good tonal integration? There frequently is a fair amount of difference between good bass requirements and the requirements of the upper frequencies. Most folks end up with some sort of compromise.
If you haven't worked all this out in advance don't be surprised if you not only don't get a 'big improvement' - you might not even break even.
JMHO - YMMV. |
Macrojack,
Others have answered your question very well and better than I could.
"Small" can be of the order of a few feet at low frequencies.
As Dave points out above, a small amount of EQ (Behringer, Rane, Rives Parc or other PEQ) can help smooth out LF bumps but cannot be used to eliminate nulls (if it aint there it ain't there and besides it is risky to apply boost as this may cause your amp to clip and damage your speakers). A PEQ should always be used sparingly and is probably best avoided above 100 HZ (use shelving functions at most and stay well away from very narrow filters above 100 HZ).
Room design, speaker placement and room treatment are preferable to EQ because this helps with the root cause. These can improve the sweet spot size and will reduce overall reverb levels (delayed vibrations). The reverberations are unlikely to be much improved by an EQ as it reduces the primary signal but has no affect on the relative size of primary signal to reflected energy.
Good luck with setting up your new speakers. Like a Ferrari, speakers with highly accurate extended LF response need careful attention and setup or they may not perform to expectation. Speakers with a smooth LF roll off are easier to handle but, have no doubts, an accurate full range speaker will perfom best under the right conditions. |
Great one Dave.
Getting off topic again with real versus canned, I have to rejoin. I have attended orchestral performances from coast to coast. I sat in a Carnegie Hall balcony with Henry Ho, builder of my amps.
Yet, I can still be brought to tears by great recordings unfolding between my speakers, such works as Rimsky-Korsakov's Sheherazade. Between full orchestra crescendos, Anshel Brusilow plays sensitive plaintive violin solos. I have to brush by a tear every time.
You can bet Henry and I were taking notes at Carnegie Hall. A smile on both our faces told all. I truthfully can say, I FEEL no difference, whether I am home or at famous performance halls.
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Yikes. The more I read, the worse I feel. I must be jumping in the snake pit to get away from the snakes. The picture I had in my mind indicated much smoother sailing than what you guys are proposing. Maybe I'll get lucky about the bass in my room. It's pretty good now with an outboard sub (also ZU) but there are definitely places in the room where the bass is more pronounced. It's especially good at my desk down the hall in the bedroom about 50 feet away from the speakers.
There's always Zu's return policy to fall back on but this project is clearly going to cost something no matter how it plays out. |
