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About almikel

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  1. something to consider... ...for some reason everyone (me included) seeks to split the low end when going 4 way with a single DEQX unit - I don't know why? It makes more sense to split the high end, that way you have a single interface (DEQX) to manage EQ and time alignment where you need it most - the bottom end... ...take a typical scenario, where you need to delay mains more than subs - if your Mini DSP is daisy chained on the analog L1/R1 output of the DEQX - you need to manage time alignment in DEQX and MiniDSP. Much easier to use the MiniDSP on the high end (preferably connected to DEQX digitally to avoid another ADC/DAC conversion). DEQX can still do speaker correction over the top of the Xover driving tweeter and mid. That will allow simpler setup/config of bass to sub Xover with only DEQX involved. The Sub channels can be mono'd, and 2 subs can be managed individually delay wise. DEQX Room EQ will be easier without an extra device in the middle. Just my 2c - having been in your position prior to going double DEQX. cheers, Mke
  2. Have you considered using the mini dsp for the top end xover instead? Sent from my iPhone using Tapatalk
  3. DEQX Owners Thread

    I'll preface this with I'm not a big passive Xover fan - I've managed to avoid them for 25 years or so, as they're much harder to implement well compared with DSP, or given you have a DEQX to run over the top, analog active (eg a simple LR4 active crossover). Amps are sufficiently cheap (especially say for a tweeter or mid range), that provided you don't add noise or an earth loop (admittedly sometimes difficult), my preference would be to remain active (analog or DSP). That said, I did seriously consider using @Paul Spencer's passive Xover for my PSE's to simplify the setup and stay with a single DEQX...after all, the DEQX can do time-alignment and speaker correction over the top of a passive Xover (although it can't manage crossover point/phase changes due to a passive Xover as the driver voice coil changes impedance). When I was planning my 4 way setup and considering exactly as you are - taking the low frequencies (R1/L1 analog) and splitting them via a mini-DSP or other solution, a wise person on SNA asked why I was splitting the low freq, not the high - I had a bit of a light bulb moment, as I already had an LR4 dbx active Xover in the cupboard to daisy chain onto R3/L3 (high freq DEQX analog outputs), and the DEQX could run speaker correction over the top as if the tweeter and mid was a single driver. IMHO it's much better to manage mid/tweeter externally and I would recommend keeping DEQX control over the lower drivers, and using a DSP/analog active or passive for the top end Xover. Keep in mind that filter delays get longer as you drop in frequency and implement steeper Xovers - daisy chaining a miniDSP on the output of the DEQX R1/L1 (low freq analog outputs) will just make it harder to time align your bottom end. You can maintain the time alignment flexibility in a single interface (DEQX) where it's important - the bottom end - then use any Xover you're comfortable with for the top end (remember your DEQX can do FR and time corrections over the top anyway. The best results will be achieved if you measure outdoors though - but far more achievable at 2500Hz than below 300Hz. In this context, by analog I assume you mean passive? No passive Xover is easy to implement, and the steeper the harder, so I would say an 18dB passive Xover would not be straightforward at all. If you want to head down a passive Xover path here's a good link to learn what's involved: http://sound.whsites.net/lr-passive.htm Vastly easier to buy or build an active LR4 analog Xover, but with the added cost of another amp. At least with an active LR4 (excluding physical time alignment of drivers) the outputs are in phase at all frequencies (edit - electrically only - acoustically it will depend on driver rolloffs - but if you can stay an octave away from a rolloff it will be close). I used my old dbx LR4 Xover daisy chained to my DEQX HDP3 to split tweeter and mid quite successfully for ages until out of the blue Alan sent me an email saying he had a 2nd hand HDP3 with digital out available - it was an offer I couldn't refuse. cheers Mike
  4. if you have the DSP tools to individually manage multiple subs (gain/delay/EQ) I see no reason to use identical subs. @Paul Spencer suggests a "heavy lifter" sub + other "fill in" but less capable subs. Geddes proposes multiple dissimilar subs. Toole discusses "bass management" of multiple subs with variable delay using a mono signal to drive them all. @Paul Spencer also suggests using your mains (where they are capable) to add additional bass sources (ie not Crossing your mains to your subs, but allowing the mains (assuming they're capable) to go lower than the low pass on the subs) This all adds to integration complexity, but achievable with flexible DSP and a measurement rig. cheers Mike
  5. Hi SB, have just scanned the whole thread when I do before and after measurements, a bump of the mike trashes the measurement - hard if you're moving treatment in/out of the room - the mike cannot move, or speakers - if you want to compare measurements. That said, your measurements are very consistent - looks like the mike didn't move Your 1st RT60 graph has far too much change in the before/after for the amount of treatment applied (IMHO) - something funny happening there Your waterfalls posted 30 July (Once upon a time there used to be numbering on posts @Marc) - show good damping from treatment above 100hz or so - as expected. I'm assuming there's no sub involved here? The dip between 40 and 90 Hz may be improved with speaker positioning or perhaps adding a sub (or 2) - it won't be fixed by absorption. You could try some eq as a no cost option - just be careful of amp clipping and driver excursion - yes most recommend not attempting to fill dips using EQ, I say try it within the limits of speakers and amps - it can help...but make things worse elsewhere in the room - EQ is like that. I'm a firm believer that treatment is the best "bang for buck" upgrade possible - especially when applied with measurements along the way. IMO some more absorption focussing on the low end would help - perhaps cover the existing "bass traps" with a membrane (eg builders plastic) to reflect higher freq - but don't expect much effect < 100Hz cheers mike
  6. agree that at 45 Hz is won't be power supply, as that would be on both and be much closer to 50Hz ...did the microphone move at all between measurements? if so that will explain the difference Mike
  7. BLOOM

    but in most listening rooms there's no such thing as direct sound below around 250Hz - the brain takes time to process, and by that time you hear the room mixed with the direct sound... Does "bloom" only come into play at higher frequencies? The term "Bloom" has no reasonable definition, and IMHO only has negative connotations of a non-flat frequency response or speaker/room resonances. Subjectivists may choose to use the term in their own way as something "good" - no different to PRAT. Anything "blooming" needs attention and rectification IMO. cheers Mike
  8. BLOOM

    "Bloom" has equally good and bad inferences based on opinion. There are no answers to this question - mods should move to the "Great Debate" forum and castigate @djb for posting in the wrong area mike
  9. Hi Jimmy, I'll likely get flamed, but bias will always impact this sort of test. To provide a similar example, I downloaded the same track in 3 different formats, 320 MP3, 16 bit 44.1, and 24 bit 96K. I listened to them over and over and heard a major difference, especially between MP3 and 24/96, and was gobsmacked my friends couldn't hear the same difference - until I handed them the remote. I was unable to reliably tell the difference when they changed the format. I'm not saying there wasn't a difference between your Hugo and the iPhone, just that bias has a big impact on results. cheers mike
  10. You didn't add the to that post - scanned a few posts and noticed Zaphod's post a page back on DACS, so I assume you meant, "DACs likely make a difference, but it could be chasing the last few %"?? Everything obviously makes a difference, including amps, but in my experience things that process/convert audio (eg turntables/ADCs/DACs/Speakers) have more chance of negatively impacting the sound. This basically covers "transducers" that convert a signal from 1 form to another, including the digital/analog conversion even though it remains an electrical signal. IMHO the ADC/DAC process is harder to implement well compared to amplification...I'm not saying good amplification is trivial though! More important is the Speaker/Headphone transducer trying to process an electrical signal into an acoustic output...and the room of course, but that doesn't apply to Cans. I'm sure under critical listening conditions you can hear differences between well designed amps - which is "better" will be subjective. In my particular audio journey I've built my system around "reasonable" electronics with more focus on the speakers and the room. I don't have much experience with headphones, but with speakers in a room, IMHO placement/treatment and EQ will affect the "in room" sound way more profoundly than the amp, assuming the amp is well designed and operating within its limitations. cheers Mke
  11. Aechmea has said it numerous times before, and I agree - Speaker Boundary Interference Response (SBIR) is often a bigger issue than modal behaviour. this advice will help to identify if that dip is room or position related (ie modal or SBIR), or something else (eg crossover). For mid-bass drivers I like to keep them close to the floor to avoid "ground bounce" SBIR issues, but subs go where they need to go to achieve the best room response. Ken Tripp (a member here on SNA) has a great SBIR calculator http://tripp.com.au/sbir.htm If you move the sub around, and the frequency of the dip changes, then the dip is likely SBIR related. If the frequency stays the same, it's likely modal, unless that happens to be the Xover pt between mains and sub. I'm not familiar with the AS-EQ1 - but these days the DSP is pretty clever (mostly ) - so probably not Xover or phase related. I don't let my DEQX decide on much in the bottom end - I prefer to do a manual setup based on measurements, then measure again and tweak - but that's just me. Ignoring all of my post above, if you install superchunks in all 4 corners it will clean up the mid bass markedly and make a big difference to the "in room" sound. Below 100Hz, in my room which has a lot of absorption, I've found EQ to be very effective, as long as you're not trying to "fix" Xover/phase issues between mains and sub, or SBIR issues. Modal "peaks" below 100Hz respond very well to EQ, so do shallow dips - don't attempt to EQ deep dips. if you want to shoot for the best room response, I'd recommend the following reading: Paul Spencer's Bass integration guide part 1 of 3 linked below http://www.hifizine.com/2011/06/bass-integration-guide-part-1/ And the Acoustic Frontiers Measurement Standards Guideline http://www.acousticfrontiers.com/wp-content/uploads/2011/10/acoustic_measurement_standards.pdf Consider the Acoustic Frontiers' paper as the "Gold Standard" target - but don't get disillusioned if your room doesn't meet it - even after treatment - my room doesn't meet their spec and I've got a fair bit of treatment and EQ in a lightly constructed room. That said, the bass response in my room is better than any other space I've critically listened to (in a domestic stereo environment). Once you hear a room with the bass under control - you can't go back... ...be careful - you may find the sound in cinemas (bars/nightclubs/concerts) just doesn't cut it anymore ... ...but the upside is you can't wipe the grin off your face every time you crank the stereo in your own room! cheers Mike
  12. 600mm wide superchunks floor to ceiling in all 4 corners will make a significant difference. As mentioned above, if going with superchunks, normal fluffy batts cut into triangles 600mm wide on the hypotenuse stacked floor to ceiling will work well. That's lots of cuts to make. As much as I hate fibreglass, they will be easier to cut neatly compared with poly. That said, fluffy poly is easier to cut than Polymax XHD (and way cheaper). Buy a bag of Greenstuf Poly batts for approx $35 and try different cutting methods. A quick calc shows the sides of the right angle triangle with 600mm hypotenuse are 424mm, so the 430mm wide batts would be perfect. You can even get rolls that are 430mm wide like this http://buybuildingsupplies.com.au/r20-underfloor-insulation-116m-430mm-roll-pack-p-28424.html that link there is a minimum order though - but that was 1 Google search Mike
  13. Looks like you have 1 sub already from the frequency response Have you tried different sub positions for that suckout? Also try some phase adjustment on the sub assuming it has some. Definitely not saying don't go multiple subs - just that you may be able to get a better result with what you have now. cheers Mike
  14. I doubt such a narrow Q dip is audible (the one around 160Hz) the broad dip around 55Hz would be