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almikel

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About almikel

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    Mike

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  1. it's important to remember that every filter has inherent delay (analog/digital/passive/active), it's just that digital filters also have processing/propagation delay (while they compute the output) in addition to the filter's inherent delay. For digital FIR linear filters the processing power required does increase as you go steeper/lower...essentially the processing/calculations increase as you increase filter steepness. In most cases the processing power of a digital filter won't be a major factor unless very low and very steep...the terminology for digital IIR filters is the number of taps, and the number of taps required increase as you go lower and steeper. IIR filters don't require as much calculation/processing when implemented digitally, so will have less "propagation/processing" delay, but the inherent filter delay will vary with frequency (ie Group Delay), rather than just linear delay. Always compromises...platforms such as DEQX will only allow IIR filters (eg LR4 or shallower) below specific frequencies based on timing (delay) thresholds. Mike
  2. Hi Warren - you'll have to explain that a bit more... I think this is very system dependant, and many members on this forum, esp those that regard their systems as "HiFi" would say "faithfully" reproducing bass guitar and drums (kick/toms/snare etc) simultaneously is not too hard - a decent system can faithfully reproduce both. On the other hand... IME, bass at live rock concerts is typically mixed as mono - it's much much easier to get even bass across the audience when it's mono. This is not to say the bass is the same across the audience space - especially for indoor venues it will vary throughout the room - just that pro mixers don't make their jobs harder than it needs to be, so mix the bass as mono. Studio albums are the place artists get funky with mixing bass guitar to a different speaker to the kick drum...hugely popular in the late 60s/early 70s when "stereo" was new, and with the "close miking" recording techniques used today, some artists/mixers go too far with "pan potting" a particular instrument to one side or the other. One of my colleagues has a particular hatred when a grand piano is close miked and the top end comes out of 1 speaker and the bottom end the other speaker...a grand piano on a stage in a concert hall doesn't sound like that... ...for capturing the "essence" of a live recording, and the ambience of the recording space, there's e a lot to be said for minimal miking - eg the classic Blumlein config - not appropriate for a rock gig, but a great example of minimalist miking. cheers Mike
  3. just keep bias in mind...without an ability to compare each with an instant switch-over, your knowledge of inserting Burson op-amps will influence the outcome. The time taken to swap the op-amps is way longer than your audio memory lasts. Enjoy op-amp rolling!
  4. I would doubt the propagation delay through a DEQX would be an issue, ie the speed of processing... ...the inherent delay (irrespective of DSP processing power) of all filters gets longer the lower the crossover frequency and the steeper the filter (irrespective of topology - analog/digital/active/passive). The processing/propagation delay of the Anthem may be miniscule (desirable), but the laws of physics will define either the Group Delay for an IIR filter, or the delay for a linear phase FIR filter. These inherent delays of filters can't be avoided, and just need to be managed appropriately. Mike
  5. Hi @Satanica - correct - I run 2 x DEQX HDP3s in a master/slave config...with the master DEQX having digital outputs to feed the "slave" DEQX. Way back in 2010 when I bought my original HDP3 I never considered digital outputs (it was an option at the time), and when I added a sub to my PSE144 + TD18 mid bass (4 way) around 2015, I had to daisy chain an analog dbx Xover to the DEQX to achieve a 4 way crossover. Alan at DEQX sourced me a 2nd hand HDP3 with digital outputs for double DEQX - which is my current master DEQX, feeding my original HDP3 "slave" unit. Alan even came to my house to help setup the "double DEQX"... ...over my 10 years of ownership of DEQX I regard their product support as exemplary. Agreed - not having individual EQ control over individual subs is IMHO a feature lacking from DEQX. Off topic - but if I was starting from scratch, and only looking at 3 way active mains (ie no subs), I would still seriously consider a DEQX HDP5 as a premium 1 box pre-amp/DAC/3 way Xover/speaker correction/room correction solution. Going 4 way takes the cost of a DEQX solution over the top...but for 3 way active mains with no subs, it's still a killer solution IMHO. cheers Mike
  6. Contentious issue - maybe valve stages need to warm up, maybe semi conductors also - I don't run any valves, and I turn all my gear off when I'm not listening - I've never noticed any change in sound during any initial "warm up" period". @Quark definitely leave it on in that case... ....me being a complete cynic also...I also find the stereo sounds better after 2 hours and several beers...
  7. typical "dynamic" (ie cone) speakers have a big inductor and resistor hanging off any crossover...you can mostly ignore any power factor issues of all the capacitors (and inductors) in the crossover. Amps typically have issues with capacitive loads - which can send them into oscillation, or they can't supply the current. Passive speaker crossovers would typically have 1 or more resistors in the signal path to prevent them presenting to much of a "capacitive" load. Mike
  8. Equating it to the power generation/distribution world it's the same thing as a poor "power factor" ie any load that deviates away from a resistive load - a big problem for power generators/distributors. Reactive (inductive or capacitive) loads have a power factor <1 (resistive loads have a power factor of 1), and require current/voltage delivery by the generation/distribution network, but the power consumed is less compared to a resistive load. A purely capacitive load wouldn't draw any power, but still require the distribution network to deliver voltage and current. Commercial/Industrial electricity consumers will often be required to install "power factor correction" to bring their power factor closer to 1 (ie closer to a resistive load). Coming back to audio, the same thing applies - the further the speaker deviates from a zero phase angle, the more reactive the load, and the more power the output devices need to dissipate in heat as they're passing lots or current, but less power is being dissipated in the load (compared to a purely resistive speaker load). Combining a low resistance load with a high reactive load can lead to power amplifiers not being happy - ie higher distortion, or worse failure of an amplifier. ESL's (eg Quad 57's, 63's) are an example of a difficult load for an amplifier - they're like a big capacitor - they don't need much real power, but they need a decent amplifier to deliver the volts/amps as required due to their poor "power factor", ie a capacitive load. Power Factor is the reason why lots of power devices are spec'd for voltage and current (V/I) rather than Watts: Power = Voltage x Current only applies where the power factor = 1 ...(although it actually still applies for power factors <1 if you're happy to deal with complex numbers, which cater for phase). Mike
  9. Cheers Andy, could you share some of the graphs/measurements with us? Mike
  10. great bass is similar to listening to good recordings - if you're in the mood you just want to turn the volume up. I sneak the bass up on the remote all the time - but only on well recorded tracks, and only where it doesn't overpower the track... It's very dependant on the mix of the master...I'm happy to tweak EQ on the remote lots...bass up/down/flat, treble up/down/flat - all to taste on a song by song basis if I'm flipping between albums...usually the EQ stays the same across an album, but sometimes you can't help tweaking the bass up a bit on some tracks. Prior to having a room with tight/dry/bass, I never mucked with the bass control. Assuming a good recording - I now dial up/down bass as I feel like it. Bad bass just gets turned down, as does overly compressed music - it's not enjoyable up loud. Mike
  11. that only covers voltage clipping, neglecting current clipping. Some speakers have dips in their impedance that demand lots of current. Many amps would easily pass your 100V DC test but would hit current limits if the speaker impedance drops low (eg ~2 ohms) - eg ESLs and Maggies. Mike
  12. what is TL;DR? I was never much of a bass nut until I: got my room's bass under control added stereo Acoustic Elegance TD18 mid bass speakers to my setup The clean/tight/dry bass got me addicted to good bass. The TD18's didn't even go that low...some friends mentioned my setup was lacking in the bottom octave when listening to the Boston Philharmonic Orchestra play "Fanfare for the Common Man", and then I listened to @jkn's setup (which literally made the hairs on the back of my neck stand up on some really low stuff). I added a tapped horn DIY sub after that...which adds subtle "weight" to the music. With a few bands of EQ my room response is reasonably flat rolling off below 20Hz. As a self professed bass nut, I find myself turning the bass down on friends' systems (after I request permission), especially car setups, when the bass is too boomy/muddy. The same goes for lots of electronic music, where the composer is adding deep bass just because they can...they just wind that knob down... I've come to realise I'm a "mid bass" nut, not a "deep bass" nut - clean tight mid bass is to die for - eg the kick drum in Fleetwood Mac's "The Chain", various percussion in Tracy Chapman's "Subcity", the drum outro in Angus and Julia Stone's "Yellowbrick Road" - my sub is only tickling the sound on these tracks, and all of the attack/bass slam is coming from the TD18s. That said I also love the realism and chasm reaching bass of Danley's fireworks and train shunting recordings - the sub adds a lot to these recordings - similarly for movies like the depth charge scenes in U571, or the lightning strikes in War of the Worlds. Clean/accurate bass with good decay (ie dry) is pretty special - and very addictive - but it makes boomy/ringing bass un-listenable. cheers Mike
  13. IMO people should focus on good integration between sub/mains/room - good integration is way more important than what sub...
  14. Maybe your current treatment is cleaning up 140Hz and above - it's difficult to determine with the variation in your frequency response above 120Hz or so...filling those dips may bring a bunch of those resonances forward in time...ie not as damped as the graph shows. The panels visible in your room photos IME would have reducing effect below 500Hz or so - they are too small/thin to have much effect below that. Based on the photos I've seen of your room, and the measurements you've shared, you have no treatment targeted at bass frequencies. My approach to room treatment is to target bass frequencies first - large/deep/gapped corner absorption treatment, using EQ below that (as treatment gets too large) to get the room's bass under control. Along the way of managing the room's bass response you could easily find you've added too much absorption of the top end...usually avoided by treatment being placed straddling corners, but you can bring back treble into the room with slats/membranes etc in front of the absorption. Once the room's bass is under control, you're >80% done with room treatment...and I'm happy to stop with any 80% solution. Your current room treatment only absorbs the top end - IMO the wrong place to start with room treatment. cheers Mike
  15. ^ this especially if seeking high SPL in larger rooms at lower frequencies. The A/V crowd (ie home theatre), pushing the boundaries of reference level SPL below 20Hz will almost always use pro amps. Multiple sealed subs with lots of EQ boost down low soak up amplifier watts like a sponge if seeking to reach 20Hz or below at reference levels. The DIY crowd will often use pro amps for their subs if not using plate amps, and also for their bass drivers in active setups, particularly if the bass drivers need a bunch of EQ to push them down to meet the subs. For a "typical" hifi setup (if there is such a thing), with a pair of commercial speakers rolling off under 30Hz-40Hz, and maybe a sub integrated below, you don't necessarily need lots of amp power. As soon as your SPL target at low frequencies rises, the more sense pro amps make as the $/watt is much lower. The downside is pro amps almost always run fans for cooling - which can be noisy. Depending on amp, some cooling fans run constantly, some only kick in as required. IME this is almost never an issue for music with low dynamic range (eg most rock music) - where with the wick turned up you can only hear the cooling fan between tracks. For classical music with higher dynamic range it's more annoying when you'll come through a crescendo into a quieter passage and the cooling fans have kicked in. I've run a pro amp for my bass end for the last decade - when it dies (putting the mocka on myself now), I'll replace it with another pro amp. It runs 400W per channel into 4 ohms into my sealed TD18 mid bass speakers, which have a big chunk of EQ to push them down to cross to my sub at around 60Hz. As far as I've noticed I've never clipped the amp (my pro amp has clip lights - many do), and the fan only kicks in when I've turned the wick up, and usually turns off before the next song starts...and I don't listen to much classical music. Some purists would reject having cooling fans entirely - from my perspective I don't care as long as I don't hear them when listening to the music. If your SPL targets require amp power >200W, then anything but pro amps become exorbitant in cost. Mike
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