Jump to content

All Activity

This stream auto-updates     

  1. Today
  2. B2 Audio XM18 vs Dayton Ultimax UM-1822

    IB? As in: good to be used in, or is this really an IB driver specifically? I'm looking at it for a small (140L) sealed in this case. Looks to fit really nicely. I have the opportunity to buy a pair of unused drivers via the AVS forum, so it's not a problem they have been discontinued.
  3. Very interesting to see the comparison. The bass levels and extension look similar, but the low-cut is much less aggressive and the content looks different. I like the looks of more mid-bass in the Atmos mix. I wonder how much re-EQ of the mids and highs they did, if any? Coincidentally, I have the rental for Pacific Rim 7.1 BD waiting to be watched, with BEQ of course. I anticipate the 7.1 BD will benefit from some cinema X-curve re-EQ as well. We'll see.
  4. B2 Audio XM18 vs Dayton Ultimax UM-1822

    I'll save you some time. The Obsidian 18's have not been in production for around 4 years now. The company (Obsidian) is no longer a company. The OA 18 was a great IB driver but was massively overlooked prior to OA being closed.
  5. That is a significant change....have you listened to the new track? JSS
  6. Pacific Rim 2013 UHD Dolby Atmos http://www.avsforum.com/forum/113-subwoofers-bass-transducers/2763785-ultimate-list-bass-movies-w-frequency-charts-166.html#post55532776 Pacific Rim (7.1 DTS-HD MA)
  7. X-curve compensation re-EQ

    I think we're getting our words mixed up here. It appeared to me that @Kvalsvoll was describing C50 as a ratio between direct sound and early reflected sound, without regard for late reflected sound: OK. I admit he described it as a ratio of "early direct sound" to "later reflected sound" in one sentence, and then described it as a ratio of "early direct sound" to "early reflected energy" in the latter sentence. Now I'm not exactly certain what he meant, but I agree with the definition @mojave posted. Though, I'm not exactly certain what he means when he writes: "On the RIR the direct sound is set to be relative time zero so it is not factored in the equation." Is he saying that direct sound energy is not part of the early energy sum? If so, that'd be quite absurd. It's far more likely the case that the "early sound" interval is meant to begin right at the start of the RIR and include the initial arrival. Anyway, we are hopefully in agreement that higher C50, meaning more early arriving sound than late arriving sound, is preferable for intelligibility. Just to repeat. Early reflections (before 30-40 ms) not only don't harm dialog intelligibility, they actually *improve* dialog intelligibility. This is discussed in Floyd Toole's "Sound Reproduction" 3rd ed., pgs 200-201 and is supported by multiple experiments. Toole introduces the section by pointing out: He also supports my point about C50 being unimportant for typical small rooms: So do acoustics matter for dialog intelligibility in *small* (domestic) rooms? No, not so much. The article is pay-walled like most. In any case, the weighting seems reasonable with regard to the relative importance of those frequencies for speech. As for speaker crossover frequency preferences, I tend to think the implementation details matter much more, and that the anechoic linear response as a whole, on and off-axis, is the most important quality. If I had to accept a badly implemented crossover though, well, I guess I'd rather it not be in the mid-range. Though, I'd rather just have a good XO. FWIW, my speakers are currently 2-way, linear-phase 8th-order acoustic at 850 Hz. I can't "hear" adverse effects of the XO at all, even when standing right next to the speaker.
  8. X-curve compensation re-EQ

    Oh yes, definitely. Up until very recent, the vast majority of music I liked was music without lyrics. Since I can remember, I could never really hear the lyrics in most songs, so I never really got into them. Only in the last year or so, since I've gotten my own system to the level of performance that it is at now, have I been able to actually understand the words in most songs. It's been quite a breakthrough for me, actually. And yes, dialog is often a problem for me on all kinds of systems including at cinemas.I might still hear 90-95% of stuff, but that extra 5% can be the difference between catching or missing a key plot point. Sometimes I have trouble understanding live spoken words. It's always a lot worse when accents get thick, especially if they are unfamiliar to me. I remember when I first moved to California, and I struggled to understand all the Asian accents. Then I moved to the east coast where I had a Greek supervisor, and I could barely understand a word he said until I'd been around him for a few months. As I said, my hearing has tested as being nearly ideal, and in fact, I tend to be more of an auditory-oriented person more than a visual-oriented person. I suspect that my brain just devoted a lot more gray matter to processing other kinds of sounds and just doesn't deal well with any unnatural reproduction of dialog. Or something.
  9. Yesterday
  10. X-curve compensation re-EQ

    Kvalsvoll is right and the Clarity score is only based on reflections as defined by ISO 3382. A Clarity score is based off the room impulse response (RIR). On the RIR the direct sound is set to be relative time zero so it is not factored in the equation. The Clarity score takes the RIR and divides it at a certain time point. The energy before the divider (early reflections) is summed and the energy after the divider (late reflections) is summed. It then does an early to late energy ratio expressed in dB. I use SMAART and get a C10, C35, C50, and C80 score for each octave and 1/3rd octave band and an overall score. C50 is used to score a performance space for speech and C80 is used to score a performance space for orchestral music. However, the lower Clarity figures are helpful for small room acoustics. Gerald Marshall provided a "Poor, Fair, Good" chart in his 1996 AES article called An Analysis Procedure for Room Acoustics and Sound Amplification Systems Based on the Early-to-Late Sound Energy Ratio. He used a weighted average octave band score with 15% for 500 Hz, 25% for 1kHz, 35% for 2kHz, and 25% for 4Khz. My preference for speakers are those that avoid a crossover in any of these bands. My JTR 215RT's have a crossover at 350 Hz and 6500 kHz.
  11. X-curve compensation re-EQ

    Do you find this in other systems or just your own system?
  12. One of the worst examples, I guess was "Star Wars: The Force Awakens", which had a limiter at -3 dBFS. While I'm sure it'd sound a bit better if the limiter were a bit higher, I don't really notice any clipping. A lot of people pointed out the heavy clipping on the disrupter canon, but I thought was an intentional part of the effect. I thought it sounds pretty cool, and of course, I usually watch it with BEQ too.
  13. X-curve compensation re-EQ

    The C50 is not a ratio between direct and early reflected energy. It's really a ratio between direct + early reflected and late reflected energy. Beyond 50 ms is generally considered to be late reflected sound. The C50 is rarely important in small rooms because most of the reflected sound arrives quite early. In large rooms in which reverb times can get quite high without treatment, the C50 is much more important. And if you try having a live conversation in a large live room with enough distance between you such that C50 is poor, intelligibility will noticeably suffer.
  14. X-curve compensation re-EQ

    This is not true. Acoustics determines the ratio between early direct sound and later reflected sound. The ratio between early direct sound and early reflected energy defines clarity. This is the case both for reproduction and when speaking in a room, and there are established standards for this. Those standards makes is possible to predict intelligibility in class rooms and auditoriums, and adjust acoustics according to intended use to make the rooms perform well. In REW there is now a Clarity graph, which shows the performance of the measured system in regards of those parameters: "Clarity C50 The early to late energy ratio in dB, using sound energy in the first 50 ms as the 'early' part. C50 is most often used as an indicator of speech clarity." The soundtrack is of course a crucial part here, but acoustics determine how well this soundtrack is reproduced, and with several sounds going on simultaneously it will be more difficult to discern the different parts of the sound when there are more and louder late energy because this late energy will then mask parts of the transient sounds in the early arrival sound.
  15. Last week
  16. B2 Audio XM18 vs Dayton Ultimax UM-1822

    @Ricci , can you weigh in on a comparison between the Ultimax and the Obsidian 18d2? I have the option to buy a pair of OA 18"s for the price of 1 Ultimax. I know the Obsidian isnt as good as the Ultimax, but in this case (I only have the budget for 1 ultimax or the 2 OA) it wouldn't be a bad start, and a good option to reach my 4x subs project a hell of a lot sooner. See the modeling below. It's in a 150L enclosure as I would use them as the back subs which are limited in their size. I modeled the Ultimax in the same volume (for comparison), and in the enclosure it would normally go (460L)(the front enclosures are gonna be almost thrice the back enclosures). I adjusted the Re of the Obsidian driver to reflect the load to the amplifier. I know you tested them both, which is why I'm asking specifically.
  17. X-curve compensation re-EQ

    While your own experiments with masking in the context of harmonic distortion are interesting, tests involving threshold perception of a harmonically related continuous pure tone in the presence of another pure tone are nowhere near sufficient to characterize masking phenomena in general. Masking is dependent on frequency, level, duration, and bandwidth of the signals. Being very non-linear, it's also not possible to predict the masking effects of 3 or more signals from experiments involving only 2. When I said "low frequencies", I meant "lower frequencies". In the case of content mixed under X-curve conditions and then played on a flat system, it is primarily the strong tilt in the upper mid and high frequencies that may allow distortion to become audible or allow mildly audible distortion to become objectionable. However, I have also had the seemingly paradoxical experience of hearing a reduction of brightness upon attenuating low frequencies. I believe in such cases, the over-abundance of low frequencies was suppressing mid frequencies that would have otherwise suppressed high frequencies. Optimizing EQ balance by ear, whether in the process mastering or voicing speakers, is a very challenging process. Fortunately in the case of voicing speakers for optimal music playback, we have scientifically validated criteria. Unfortunately, the cinema industry relies on its own standard for system calibration that lacks scientific validation and is inconsistent with the criteria for optimal music playback. Wait a sec. You're telling me that people struggle to understand dialog in movies because of strong early reflections, poor decay time, and non flat frequency response, yet in reality, people have zero difficulty having a live conversations in these same rooms. This is despite the "deficiencies" that you identify here concerning early reflections, decay, and "poor" in-room frequency response in the mid-range, and non-flat frequency response in general, which affect live voice just the same as voice reproduced through a speaker. Logically, the acoustics are only a minor factor. The remaining issue(s) to consider are the speaker and the soundtrack. Yes, most speakers are not very good, and this is a real problem. On-axis neutrality and off-axis consistency are crucial. However the *average* response of a wide variety of speakers is approximately flat, when measured anechoically. However, whereas music tracks are produced mostly on systems that are very close to anechoic flat, cinema tracks are produced mostly for cinema systems that have very skewed responses, due to the X-curve calibration process. So there are two major problems regarding dialog intelligibility: non-neutral speakers and non-neutral soundtracks. If either of these deficiencies improves, the overall result improves, and that may be enough to make dialog intelligible at least. For high quality reproduction, of course, it's essential that the monitoring and playback speaker responses (anechoic, not in-room) are consistent.
  18. B2 Audio XM18 vs Dayton Ultimax UM-1822

    Seems like powersoft is sold quite often in my area, so when I upgrade my amp I can probably go for one of those (for example a powersoft digam d1604 2 x 800 watt for 350).
  19. B2 Audio XM18 vs Dayton Ultimax UM-1822

    Yeah, I figured it out few minutes after I posted this. I also took account for the DC resistance. Reading up on voltages and amps is my next goal. I think I understand the main principles, but really implementing it into the modelling and taking account for it will take some more reading. The winISD help page had a few things to say about it, and it also has a few graphs I have never used before that could maybe show this driver/amp relation over the spectrum. But again, will have to read up (and start from the beginning) to really grasp it. Thanks for the tips! I already tried to find some specs about my amp, but no voltages to be found. I might try to calculate it again. Reason why I'm not spending all too much time on it is, because my priority is the sub at the moment. After I have this (and maybe the second one), I'll start looking into the right amp. I'll have a look out for those amps! And have a read on the forum. I'll put up some search notifiers for a few good choices so I can grab a decent one when it hits the market locally. The iNukes go for dirt cheap, both in general as on the second hand market over here. I could get an iNuke NU4-6000 for 300 eu or less. Sometimes I see an iNuke NU6000 for only 150.. I'm gonna read up on those first, but even if it only delivers 25% of what it states, it would still be 750-800W/channel.
  20. B2 Audio XM18 vs Dayton Ultimax UM-1822

    The "Transfer Function" screen shows simulated response *relative* to output in the high frequency limit while ignoring inductance. All the comparison is showing you is the simulated *relative shape* of the response without EQ under ground plane conditions and not the absolute sensitivity or efficiency. Even then, the shape shown is not accurate for the upper frequencies because the simulation of inductance effects in general is very inaccurate. I suggest ignoring the transfer function screen because the information shown there is largely irrelevant if you are using EQ. Try looking at the "SPL" screen instead. Ensure that both drivers are configured with comparable "power" inputs. Note that comparable are not necessarily equal. The DC resistances of the drivers that you are comparing are quite different. This is where you need to really understand the relationships between voltage, power, and impedance. The "power" input in WinISD is actually converted to a voltage, the voltage that would deliver the specified power into the DC resistance (Re) of the driver: V=sqrt(Power*Re). So if you have a max voltage spec for your amp, you can input it as the "power" by computing Power = (V)^2/Re. That gives you an upper bound on potential output. From there, you can check on excursion to ensure it is within limits. And lastly, you need to look at the impedance curves to figure out how much actual power will be demanded from the amp at different frequencies. For a given voltage and impedance, actual Power = V^2/Z. The amp specs should list power capability for one or more impedances. If the impedance you are looking at is lower than what the amp specifies a power rating for, it's probably not a good choice of amp to use. Realize also that most amps have exaggerated power specs. They may give a number that's only valid for very short-term "bursts", which may not even be long enough to complete a full cycle at 20 Hz. This is the case with many pro sub amps which are more typically used only at 30-40 Hz and up. The question of real world amp performance is a whole other issue but is very important to consider as part of the "system" design. As long as the driver is within its excursion limits, the ultimate performance depends a lot on the real world performance of the amp(s)together with the impedance profile of the sub. Amps also have sensitivity roll-off in the lowest frequencies, which is important if you are trying to push below 20 Hz and especially the single digits. As with drivers, more capable amps are usually more expensive, but price is absolutely no guarantee of performance. The best sub amps, IMO, are from Powersoft and SpeakerPower. Neither are cheap. Plenty of people get by with the inexpensive Behringer amps, but realize that those amps don't deliver as much power into low frequencies as their specs claim. Have a look around here and AVSForum for measurement data.
  21. X-curve compensation re-EQ

    Too much information, but i appreciate your dedication to elaborate and explain your thoughts, and I did read it all. I have selected a small subset from your post to comment on, realizing we can not cover all aspects of sound reproduction in a few posts in this thread. Distortion and masking: Distortion components at higher frequencies are not masked by low frequency content, unless this content also has higher frequency harmonics sufficiently loud in level. Masking occurs around the fundamental tone, and when the difference in frequency is large enough there will be no masking at all. For low harmonics the masking is high, so that for 2. h the detection level is around 2%. For higher harmonics, or any other content at much higher frequency, the detection level approaches the audibility limit for a tone at that higher frequency, as if the low freq tone was not present at all. I know this because i have preformed a controlled experiment just for the purpose of investigating detection level and masking for harmonic distortion. Dialogue: Yes, some dialogue can be more difficult to understand, and whether you experience intelligibility to be sufficient or lacking will always be a subjective evaluation. And some systems will be better and some worse. The typical home system with a center speaker close to the floor and a table between this center and the listening position is not a good starting point. In such a system, it is likely that the frequency response is very compromised through the midrange, and there will be severe early reflections. This causes poor intelligibility. A simple measurement will reveal that freq resp is far from flat, and early decay is poor. On top of that, I suspect that many center speakers have problems with both on-axis frequency response and poor off-axis linearity. In many cases room acoustics is not suitable for sound reproduction because the room is not sufficiently damped, causing problems with overall decay and early reflection level. This is the reason for all those "can't hear the dialogue" comments. The only solution to this is to improve the sound system and room acoustics.
  22. B2 Audio XM18 vs Dayton Ultimax UM-1822

    I think I'm doing something wrong.. I have no idea where though.. This is the "transfer function magnitude" I get. I was comparing Obsidian vs Ultimax, and included the SHS24 for reference. How is it possible that 2500USD driver performs so badly? Worse than Doesnt matter what kind of Volume I enter.. I tried to check if I messed up that driver inputs, but I cant find anything. Any suggestions on what I'm doing wrong? Or am I not wrong, is it just because the strength of the SHS lays in it's power to handle 5 times the RMS and its much higher Xmax? Also just finished my biggest exams, so I got time to read up. I'm reading the complete winISD beginners guide, which is already really useful! Primarly on how to design ported boxes. It's looking a lot simpler! Might find the answers to my questions above too. If you have a more indept guide on everything concerning designing speakers (or a good site) I would love to hear it. Interesting stuff! Also designing my custom height speakers at the moment, and it looks like going ported is the way to go there too (if youre interested: it will probably end up being a 15" Eminence kappa 15LFA woofer in a 62L box tuned to 60hz. On top of it I'm gonna place a HF200 driver paired to a PH4525 horn. Crossover will be active.)
  23. B2 Audio XM18 vs Dayton Ultimax UM-1822

    Yeah I know, again, the 24" was just alluring because of the shear size I think, starting of with the single (and extentions to a second) 18" Ultimax sealed/ported or 21" B&C ported is definitely a great way to start. Decision to be made in the next few weeks. The 24" will be something for the future. Definitely hoping to get there. Although that definitely depends on how the first 2 subs perform. 2 "developments": There is someone on AVS forum selling 2 x Obsidian 18" Subwoofer, which look like very decent woofers (not the best, but surely not a bad start). They would cost the same to ship etc, as 1 Ultimax. I realised my new size measurements are exactly the same as 1 Othorn or 1 Tuba HT. They don't dig as deep, and I'm not planning them for now, but it's good to know I do have the option. The double 18" and upgrade to an extra pair of 24"ers is definitely alluring. Something for later, but a nice prospect. I doubt I would need the advantage of ported if I go for 4 subs (especially if I also decide to throw a few crowsons into the mix). Money is always relevant, but in my case.. well I decided that I don't mind spending all the money I have into this. If everything goes well I'll have almost everything in my surround upgraded up to a point that I cant improve significantly without spending a fortune. Maybe on my amps, but oh well. Rather spend it on subs I have the option for 2x 460L enclosures, but all the other ones will have to be significantly smaller. Or to be more precise, the ones in the back or rear would have to be. So it's definetely sealed there. The fronts has options, and a lot of spare room. I have a wall of 4,2 meter in a 60cm deep protrusion. Let's say the subs cant be higher than 90cm, I have 2270L of space in the front (-the material of the enclosures and drivers etc). All the fronts speakers would lay on top of that. So for future reference, I can build my 460L enclosure now, and still have a lot of spare room (2x times 675L) for very far future upgrades. Something I'm definitely not against. So maybe I should start of with the 460L enclosures, sealed. It's simple and much more forgiving against mistakes. Next step would be another pair of small sealed cubes for in the back OR I could make the 18" hole in my main 460L enclosures bigger so it could fit a 24" er (HS24 probably), and make small sealed boxes for the 18"ers I took out. That way I can start of with 1 18" er in a small design, which I can manage with my specific enclosure measurements, then build a second one. This could be managed within the near future. Maybe even instantly if the Obsidian measures well etc. After that I can see what I want next. Another pair of 18" ers, a 24"er, if so which one, maybe a horn, etc etc. I'll start modelling the 5 options now (Obsidian and Ultimax in sealed and ported, and the B&C driver as it's looking like a good option), all in the same 460L enclosure.
  24. Hey buddeh! Unfortunately I don't have the capability for BEQ. I have to agree with you tho, Max brought over his demo disc of BEQ'd stuff when I had my last g2g and it was unbelievable the difference that BEQ can make. Just astounding.
  25. B2 Audio XM18 vs Dayton Ultimax UM-1822

    I was thinking of my follow up response. I kept thinking, sure a couple 18s would be phenomenal and may fit into his budget now. If you were to buy 4 HST-18s, you’d have one of the best subwoofer systems on the continent. Or a pair of HS-24s would do the same though the quad 18s in the corners would provide more even bass in most rooms. Realize that we’re talking about bass systems in the top 1% in the entire world. That is going to cost some money but then again, is a value compared to what most uninformed consumers pay for their “high-end” audio equipment. Either way, this system should last you 10 years and likely many more than that so I’m of the opinion to save your money and get what you want. Or even better, start with a pair of 18s and add a pair of 18s later and you have almost the equivalent of a pair of 24s and more even bass. Or buy a pair of 18s now and add a pair of HS-24s later where the 24s would be up front and the 18s in back. And if you want the real deep bass and smaller cabinets, that would be sealed and I oh so love the sound and tactile feedback of my sealed 18s and 24s. Then again, if you’re not interested in single digits or are on concrete, then a ported 18 may be the way to go. You’ve definitely have some options and won’t go wrong listening to the experts on this forum.
  26. B2 Audio XM18 vs Dayton Ultimax UM-1822

    Let me remind you of what I said in a previous post: The IB-24 is not designed for "small" boxes. It doesn't have the motor strength or the coil power handling to perform well in a small sealed enclosure. If you want low and loud in a small box, you have to spend $$$ on drivers and amp power. If you want to go 24" sealed in the cabinet size you're contemplating, then you should save up for the HS-24 at least. I'd still recommend building two of those boxes at least if you want them to keep up with the rest of the system. Or you could save up even more for 2 x SHS-24 and get good performance from both in a single 16 cuft cabinet, if you use a huge amp. See how this works? Low, loud and small cost lots of money!
  27. Ricci's Skhorn Subwoofer & Files

    You would have some port chuffing with the 19hz tune and using the 21's. BUT since the 18's dont move as much air as the 21's you will most likely be fine with 19hz tune and using the 18's. Thats what I was saying in my earlier post.
  1. Load more activity
×