Cleve Posted December 23, 2004 Share Posted December 23, 2004 Finally bought a Rat Shack sound level meter - the analog model - catalog 33-2050 is on clearance for a paltry $14.97!!! At any rate, I was curious to quantify the performance of my CF-4's. I knew they were capable of prodigous bass, despite one review I read that said "won't play low - at all" or something like that. So I placed the meter 3 feet from one speaker and about 1' above floor level. I switched to mono, and turned off the other speaker. I 'pumped' enough power into the CF-4 to read about 85 db at 50 hz - which equals about 1/10th of a watt on my Mac 2205. That's where my test begins. The attached graph shows the rest. I tested with sine wave .wav files of 50, 45, 40, 36, 32, 28. 25, 22, 20, and 18hz... The bass rolls off slowly, but hangs tough through the mid to low 20's The bass doesn't really plummet until 20 hz and below. This pretty much confirms my own impressions of massive bass capability The thing is... these speaker don't accentuate the bass - if there's no bass, they don't produce bass. They don't emphasize, or color the sound in my opinion. Maybe that's what the one reviewer meant by 'won't play low'. LOL Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted December 24, 2004 Share Posted December 24, 2004 Cleve, Did you correct the Rat Shack readings? The lower that you go the farther off the meter is. There is a correction table bt frequencies. Bill Quote Link to comment Share on other sites More sharing options...
Olorin Posted December 24, 2004 Share Posted December 24, 2004 Here's one -- http://pwp.t-3.cc/ttriff/subtestmodel.xls Quote Link to comment Share on other sites More sharing options...
Cleve Posted December 24, 2004 Author Share Posted December 24, 2004 ---------------- On 12/24/2004 1:12:41 AM MrMcGoo wrote: Cleve, Did you correct the Rat Shack readings? The lower that you go the farther off the meter is. There is a correction table bt frequencies. Bill ---------------- Bill, thanks for the tip. No, I didn't - here's a 'normalized chart' - I had to interpolate some of the values as my test Sine Waves didn't correlate exactly with the frequencies listed here... http://forum.audiogon.com/cgi-bin/fr.pl?htech&983682086&openflup&1&4 So here's my 'corrected' chart... ...and the bass performance is more impressive... the -10db point isn't hit until ~20hz!!! And by the way, MAXIMUM SPL at 1 meter 40 hz, 1 speaker driven is a whopping 109.5 db!!! That's at 200 watts continuous - I didn't drive the 2205 to clipping, just until the needle rested steadily on 200 watts. With a 300 watt amp, which is the maximum continuous the speaker is rated for, maybe 111 db at 40 hz Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted December 24, 2004 Share Posted December 24, 2004 Those neodymium magnets on the CF series can really belt out the bass. For a given weight, they are about ten times as strong as mud magnets. That is as close to a "full range" speaker as I have seen. If you have a KV-4, you can do home theater without a subwoofer and not miss much. Bill Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 24, 2004 Share Posted December 24, 2004 "despite one review I read that said "won't play low - at all" or something like that." Cleve, What do "they" know? That is what "they" say about the Khorn too. All they do is read the spec sheet which says "35Hz to 17KH" and think they don't go below 35! What those are are the =/- 3Db points. Many speaker manufacturers use the "standard" -10Db point for "usable" bass. Which is about 28Hz, the cut-off frequency of the folded horn. And they do it without high levels of distortion, "doubling" or artificial "warmth" (artifically higher bump in the output level) about 100Hz which many "proffessional reviewers" seem to favor. The Khorn will still shake the walls down to 20Hz but don't develope a wave. Nice graphs! Rick Quote Link to comment Share on other sites More sharing options...
tunemanjjw Posted December 25, 2004 Share Posted December 25, 2004 Is your room really large? not trying to trump, but I get max SPL on my rf-7's at just above 40Hz at 125db on my rat shack meter Quote Link to comment Share on other sites More sharing options...
Cleve Posted December 25, 2004 Author Share Posted December 25, 2004 Tuneman, I don't know what 'really large' is - the room is about 23' x 22' with standard 8' ceilings. Something else - it has a drop grid ceiling with 2 x 4 panels, so I'm assuming they'll absorb sound as well. Also, my CF-4 is a good 6 feet from the room corners - the way the room is laid out there's no way to fix that either without a major remodeling project. So I guess we'll forget maximum SPL - as I think about it without uniform measuring rooms, it's somewhat meaningless. Probably these other measurements are equally meaningless, but fun anyways So here's three more graphs! LOL - First is a test of my Klipsch RW-12 subwoofer with the Lowpass filter set to 40 hz Second, my RW-12 subwoofer with Lowpass cranked to the highest level - 120 hz And here's how my CF-4's low frequency performance 'meshes' with the RW-12 from 16 Hz to 57 Hz The graph confirms what my ears told me ten months ago - For Home Theatre, it's fine to run them together, but don't use the RW-12 for music!!! IF the Lowpass filter at 40 hz was more aggressive, the subwoofer would mate better with floorstanding loudspeakers like the CF-4. Unfortunately, the response for the RW-12 remains quite flat out to 100 hz, even with the filter at maximum cutoff. It really doesn't roll off until higher frequencies, which is unfortunate. And from 30-60 hz, the subwoofer and speaker are very close in response. Running the two in combination makes for boomy, colored bass, for the majority of music. I wished Klipsch had built a more effective filter into the subwoofer. Quote Link to comment Share on other sites More sharing options...
tunemanjjw Posted December 25, 2004 Share Posted December 25, 2004 U rite, the graphs are great fun. I think u should keep posting them. FYI, the room i'm in is a lil over 1/3 the size of the one described Quote Link to comment Share on other sites More sharing options...
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