davewantsmoore

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About davewantsmoore

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    Log! It's big, it's heavy, it's wood.
  • Birthday October 16

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    Hobart
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    Dave

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  1. The depth is 10cm, and yes there is a distance before the simulated diffusion applies (eg. 2.1m in the charts in the link). http://www.ebay.com/itm/Skyline-QRD-Fractal-Sound-Acoustic-Diffuser-Diffusor-Panel-Absorption-Treatment-/232091714480 The doesn't mean they're completely ineffective closer, just you won't get the same pattern as the the simulator (this distance is frequency dependant AFAIUI) .... so moving closer than 2.1m would affect the LF performance to begin with.
  2. The ones in the picture. I got the ones from Latvia/Ebay posted earlier. Just 1.2m x 0.6m to play around with at some stage.
  3. Sure ... but this will mean the crossover to the subwoofer will be quite high in Hz .... and so the subwoofer placement becomes restricted to being close to the main speakers. It's quite a generalisation .... this would depend on the coverage pattern of the horn system. Horns can achieve some of the most well controlled coverage patterns (one of the major reasons to use them) .... but many horn systems have really problematic coverage patterns.
  4. Yes, just the sort of thing I was thinking of. I think he has one which might go a little lower too, if you have space. Get rid of the QPs Build Inlow ~100Hz horn, or similar Build subwoofers to cover below the new midbass horn ... build more subwoofers. : party :
  5. More bass drivers is always good advice Autocorrect should make subwoofer => subwoofers
  6. For the majority of people, it's the only place you need it .... or at least where it's needed most.
  7. I got a coupe of these made after I saw your post re: polystyrene.
  8. This is typical of a normal folded (doesn't go high) horn that isn't enormous (doesn't go low). As you know, I have also built a very similar horn. You could use a different woofer in it to get it to reach higher in frequency ..... but I don't think the dimensions of the horn make it suitable to operate much above bout ~350Hz anyways. If you're going to keep your existing 340 horn, and use direct radiators. I would recommend a "mid bass" driver mounted below your mid horn which covers ~80 to ~600 .... and then true subwoofer(s). You could also cover this range with a horn, but it will be very big ..... think 3/4-ish the mouth size of your "QP horn" .... 3/4 as long, but not folded.
  9. Paul. My understanding is Dave currently has a horn which covers from 60 to .... not high enough to meet his mid horn (about 600hz). I think it's a good suggestion .... to use a subwoofer(s) .... and then a driver (or a horn) to cover the range from the subwoofer to his mid horn (eg. 80 to 600)
  10. Yes, you can do that .... and I guess you'll need to if you don't know how to start from scratch. Another, perhaps obvious option would be to get a horn which reaches from your subwoofers to your midhorn.... so like from 100 to 800 or something.
  11. Yes. What most people describe as "slight" is really nothing of the sort Decibels are big. That's correct. However frequency response is complicated, as it is changes with the angle we view the speaker from..... and we hear the summation of all the sound dispersed into the room. So, if we measure two different speakers from the same angle and difference..... even if they read the same response, becuase the speakers produce different responses at other angles ...... the sum of all their energy is different .... and they sound different. I figured he meant the "house sound" of a speaker. Depending on the Q of the change..... VERY! With extremely low Q (ie. over a wide range of frequencies) over a wide angle (if it's a speaker) .... very small fractions of a dB can be audible. Becuase they are measuring the output of the amplifier connected to a measurement rig using one simple stimulus .... and not the output of a speaker connected to the amplifier, while examining a range of stimulus. Some amplifiers produce a load dependant frequency response..... I've posted some charts in the past of various amplifiers driving a speaker and the differences in steady state response.... a few amps up to 1 or 2 dB over a wide frequency range. ... but there's also dynamic conditions (ie. what happens to the response as other things change). An analogy would be like putting two similar cars on a dynamometer, and driving them at 60km/h .... they will usually perform extremely similar. .... but other more complex test will tease out the differences between them. 0 to 60? .... 60 to 0? ..... with 4 passengers? .... with 600kg in the boot? ..... holding a constant 60km/h around a 90 degree corner? These same tests at 5km/h? .... At 150kmh? Measurements tell you everything about an amplifier..... but what and how to measure, and how to present the data is very complicated. Just like measurement (can) tell us everything about the human body.... but if we were to take eveyones body temperature, and then try to decide if they had heart disease or not ..... then we might start to think that 'measurements don't tell the whole story'
  12. If you're going to build the Majestic speaker .... then you will need to use the exact woofer and horn/tweeter they specify. http://www.diysoundgroup.com/waveguide-speaker-kits/fusion-15.html You might be able to get someone local to design you something very similar.... and then provide the bits you don't want to build on your own (example: if you didn't want to assemble a crossover) .... for example, something with that etone driver, but with a better tweeter and crossover. Yes. Chose a speaker which is a fairly high efficiency, and fairly flat impedance.
  13. I agree with the sentiment. ... but you can have both for $1500 (but it is tight, yes). Search term = "econowave"
  14. At least a decade in the mainstream from my understanding of DAC architecture. Hmm... I can't read Japanese (and can't find an English datasheet) ... but that does look like some sort of hybrid architecture. I was more thinking about the ESS Hyperstream (10 yo)
  15. Ah ok, I see (I knew that) ..... Sorry, I was confused about personal morals, vs the website rules.