discusman Posted January 2, 2002 Share Posted January 2, 2002 Hi all ... happy new year!!! How accurate is the sensitivity rating on the klipsch speakers ... the chorus II in particular. It's listed at 101db and i normally don't care since i'm using a 200WPC SS amp. Well now i'm thinking of buying an ASL Orchid SET integrated amp ... it's a 3.5 WPC 2A3 integrated. The person i'm buying this from highly recommends it but only if the sensitivity rating of my speakers is as stated ... so i told him i'd ask the folks here. Comments anyone ...... Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 2, 2002 Share Posted January 2, 2002 I have read from countless sources that the Klispch Reference series speakers are WAY over estimated reguarding senstivity, sometimes up to 3-5pts higher than what they really measure. On the other hand, most of the vintage Klipsch are very accurate in the stated sensitivity specs. As for the Chorus speakers, these probably have a better chance of being as stated although 101 does seem rather high. kh Quote Link to comment Share on other sites More sharing options...
discusman Posted January 2, 2002 Author Share Posted January 2, 2002 thanks kh ... that's the same thing this person told me ... that the actual output of klipsch speakers are less than what's in the specs. anyone feel that i should worry about driving the chorus with 3.5 WPC? Quote Link to comment Share on other sites More sharing options...
edster00 Posted January 2, 2002 Share Posted January 2, 2002 discusman- I thought you were going with the ASL MGSI15DT/s? I can't attest to the accuracy of the Klipsch speaker sensitivity ratings. I can say that what a manufacturer claims for their amps output rating may not be as clear as a speaker's sensitivity rating. I have tried various low(er) powered amps with my Khorns. I found the MGSI15DT/S (@5wpc Triode) to start clipping in the low to mid 90 dB range (with my components in my listening room). I found the same thing with the Decware Zen Signature monoblocks (~@3.5 wpc also). I now have the Welborne Labs monoblocks (~@3.5wpc) and I have plenty of volume to spare with ablolutely NO sign of clipping or strain on the amps. They are just running along pretty as you please at >95+dB's without breaking a sweat. I absolutely love these little amps...I think you will enjoy the 2A3 tube also! ------------------ Ed W Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 2, 2002 Share Posted January 2, 2002 What ole Ed is saying without really saying it is the fact that the amp design/components and, ever more importantly, the OUTPUT transformers really do establish much of what you get as far as sonics and output. Indeed, as a Welborne Labs 2A3 Monoblock owner, I can attest to the amazing low end drive and power from these 3.5w or so monoblocks. My units have the MagneQuest DS-025 output transformers while Ed's employ the Electraprint outputs. Either of these output transformers are far superior to what you will find in the Antique Sound Labs gear, especially at the lower price points. The Moondogs have a choke regulated power supply with BlackGate and/or ELNA Cerafines mated with ~600v Solens throughout the power supply. Wattage is the most overblown/misunderstood spec there is and this applies right on down to the ultra low power amps such as a 3.5w Orchid vs the 3.5w WL 2A3 Monoblocks. Many people also speak of the little Decware Zen amp which cannot compete with something like the Moondogs concerning low end extension. As I have said before, how do you explain to someone that these 3.5w SET monoblocks have more bass slam and articulation than a Bryston 4B-ST 250w solid state powerhouse, this via 98dB Cornwall I speakers? In order to get this, however, you will have to pay the extra ducats for top notch outputs and circuits. Still, good used deals can be found. kh s y s t e m Linn LP-12/Linn Basic Plus/Sumiko Blue Point Rega Planet Cary Audio SLP-70 w/Phono Modified Welborne Labs 2A3 Moondog Monoblocks DIYCable Superlative / Twisted Cross Connect 1977 Klipsch Cornwall I w/Alnico & Type B Crossover system one online / alternate components / Asylum Listing f>s> This message has been edited by mobile homeless on 01-02-2002 at 03:29 PM Quote Link to comment Share on other sites More sharing options...
discusman Posted January 2, 2002 Author Share Posted January 2, 2002 hey ed ... actually i do have the MG-SI15DTS right now. the switch from pentode to triode snapped off so i'm having it replaced ... but also have the option of changing if i want. The orchid model is supposed to sound better but a little more expensive but less power. do you think it's worth the $300 difference?. It does have a remote control but i'm hoping the price difference is because of the design and tubes used and not the remote. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted January 2, 2002 Share Posted January 2, 2002 Mobile H., "As I have said before, how do you explain to someone that these 3.5w SET monoblocks have more bass slam and articulation than a Bryston 4B-ST 250w solid state powerhouse, this via 98dB Cornwall I speakers?" I have to hear these amps,if what you say it true then I will try and but these. The Cornbreadwall speakers dont need too many watts to sing. TheEAR(s) Now theears Quote Link to comment Share on other sites More sharing options...
edster00 Posted January 2, 2002 Share Posted January 2, 2002 mdeneen, I "eyeballed" it on a rat shack SPL meter ("C" weighted slow mode) ~18' from the speakers. Bear in mind that I have ~1000 lbs of "room treatment" (that looks and feels exactly like a pool table) between my listening position and the speakers. I am sure I could hit >100dB's ++ at my listening position, but the volume control on my preamp won't go past ~11:00 position for some reason. My wife wants me to leave it like it is but I need to get it fixed soon . discusman, I don't know about the price difference, I just like the 2A3 sound better. Did you like the Triode or Pentode mode best on the ASL? I think most remote control options are in the ~$500 price range, I would want to be sure you are getting better iron with the Orchid, not just more pricey because of the remote. ------------------ Ed W Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted January 3, 2002 Share Posted January 3, 2002 Before we let the inaccuracy be taken as fact, I would like to mention that the sensitivity specs of Klipsch speakers are not overstated. We use legitemate, repeatable measuring methods. There are many different methods of rating sensitivity, but we do not attempt to hide behind specs. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 3, 2002 Share Posted January 3, 2002 How do you measure your sensitivity? Could you list the criteria you use for the Reference series? kh Quote Link to comment Share on other sites More sharing options...
mike stehr Posted January 3, 2002 Share Posted January 3, 2002 I'm with Discusman, I have Chorus II's. THANX! Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 3, 2002 Share Posted January 3, 2002 Bob G.-- Some of the specs of your home speakers seem rather hinky, take the RF-7. An F3 of 32hz and 102db efficiency in a box only 5 cubic feet or so?!!? C'mon Bob, that's an outrageous claim. Look at the JBL 4648 bassbin; F3 of 45hz, 8 cubic foot box and efficiency of only 100db. Heck, never mind the JBL, look at your own pro speakers. The bassbin of the KPT 904 theater speaker is 10.5 cubic feet, efficiency of 103db and an F3 of 45hz. So the extra volume of the speaker, compared to the JBL, allows higher efficiency with the same F3. So I'm supposed to swallow that the RF-7 has practically the same efficiency, better than a half octave lower F3 and in a cabinet less than half the size? I'm not buying it. I'm not saying you can't have a 32hzF3 or 102db efficiency or a 5 cubic foot box, only that you can't have all 3 things at once, pick any 2. Quote Link to comment Share on other sites More sharing options...
djk Posted January 4, 2002 Share Posted January 4, 2002 Marketing types are allowed to ignore the laws of physics, it says so in their job description. I 'created' a speaker in my computer box program. 102dB/W/1M with an honest to god 8R minimum impedance and -3dB at 32hz. With a Qts suitable for a Qb3 alignment it takes a 40 cu ft box. With 32 cu ft the F3=34.1hz, 24 cu ft F3=37.5hz, 20 cu ft F3=40hz, 15 cu ft F3=45hz, etc. If you allow for 'room gain' of 3dB from 100hz to 30hz http://www.adireaudio.com/Files/VentedShivaApplications.PDF you can use a lower Qes and Vas to keep the same midband No=6.782% and reduce the box sizes 50% from the anechoic data given previously (if you have 1/2" sheetrock on sheetmetal studs for walls and/or an open floorplan forget about the room gain). Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted January 4, 2002 Share Posted January 4, 2002 Klipsch measures sensitivity on home loudspeakers in the following manner: 1. We place the speaker to be tested in our anechoic chamber and do a free space measurement (no boundary gain or room gain) at a distance of 3 meters. This distance is chosen in order to be in the far field of the speaker. The test signal used is wide band pink noise. 2. Starting with this result in dB, we add 9 dB to obtain a one-meter equivalency, as the industry standard for expressing sensitivity is one meter. The 9 dB difference is all inverse-square gain. Move half as far away and gain 6 dB etc. 3. To this we add 4 dB for room gain and boundary gain to translate the measurement to a typical listening environment. Speakers are not operated in free space in any normal application. An increase in sound pressure comes from proximity to nearby walls, floor and ceiling. Theoretically, a maximum of 18 dB increase is available through corner placement but that is rarely the position chosen for full range loudspeakers; and the increase is also frequency dependent, being prominent at low frequencies. Additional measurable increase comes from room gain wherein the room is pressurized by low frequency information. Again, this is frequency dependent impacting only the low end of the spectrum. We have verified the 4 dB figure we use in numerous empirical measurements and believe it to be quite accurate. Our KPT-904 professional theater speaker was mentioned above. It should be noted that the KPT-904 is a model designed to be placed behind the screen at a movie theater and as such does not benefit from as much boundary reinforcement as in a typical home installation. The 4 dB room gain figure is not applied to the sensitivity measurement for such models. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted January 4, 2002 Share Posted January 4, 2002 But if you were to use the mentioned theater speaker in home enviroment, would you add the 4 Db gain also, to get a theorectical idea? Was this gain addition averaged from different room sizes? Quote Link to comment Share on other sites More sharing options...
mace Posted January 4, 2002 Share Posted January 4, 2002 Bob, Thanks for the answer! Since some of the discussion had to do with old vs. new Klipsch home speakers I was wondering... has Klipsch altered the method for which they obtain the efficiency rating? If so, when? Just curious... On the note of speaker performance, are the frequency response curves available somewhere for the Legend, Reference and Heritage lines? Thanks, Mace Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 4, 2002 Share Posted January 4, 2002 Bob G.-- So what's the F3 of the RF-7 into a hemisphere? I understand room gain and boundary reinforcement but that is so room and position dependent as to really not be part of the nature of the speaker itself unless the speaker is designed for specific location like Khorns or old Allisons. When I read specs I want to know the nature of the speaker itself, what does your box design program show the F3 as? Most serious speakers are speced into a hemisphere or free-field. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 5, 2002 Share Posted January 5, 2002 There are many people who do not readily know what the impact of room boundary effects are on the sensitivity of a speaker. I agree with Tom here. It is better if we just know what the speaker does. Since no two rooms are alike, and since no two people set their speakers up exactly the same. There should be only one standard so consumers can make valid comparisons. I guess a valid question would be: How do other manufacturers measure the sensitivity of their speakers? ------------------ deanG This message has been edited by deang on 01-05-2002 at 02:22 PM Quote Link to comment Share on other sites More sharing options...
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