Jump to content

Red Spade Audio

Members
  • Content Count

    288
  • Donations

    $0.00 
  • Joined

Community Reputation

246 Excellent

3 Followers

About Red Spade Audio

  • Rank
    250+ Post Club

Profile Fields

  • Location
    Melbourne
  • Country
    Australia
  • First Name
    Paul

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Good point - in a nutshell yes, but I'll elaborate a bit more ... Given the way that most people position and integrate subs, one better quality sub is a safer bet. Often the decision is based on a combination of aesthetics/pragmatics and how it sounds initially. Around 80% of the time, there is a better position. It's a multi step process to find it. With one sub, it's already very difficult to find the best position, relying on how it sounds. The sub crawl will often result in a bad decision. The position that sounds best in a sub crawl, without any EQ, may actually be a poor choice. If you are using two subs, the challenge is far greater. It's like driving to work blind folded, hoping to navigate by the sound of traffic and all the car horns blaring at you! You really can't do it without measurements and the right process. The result may be inferior to a single sub, often due to sub-optimal positions and phase related cancellation. Without measurements you may not recognise that this is happening but you will certainly notice the difference when things are fully optimised. Putting a single sub into a room normally yields +/- 15 dB in the bass region. I've seen DIY efforts that worked very well. I've also seen pro jobs that were done poorly. The key point is this: I'd recommend two choices. 1. Buy one sub, the best you can afford and take your best crack at finding a good position, try as many as you can. 2. If you want to go the next step and add a second, keep in mind it will take measurements. That means either a learning journey or getting help. Reminds me of a Karate kid quote. Just after My Miyagi rescues Daniel from getting beaten up, he says: In this case, if you buy two subs and plonk them down randomly, it's not so much that you get squashed like a grape. Rather, it's a missed opportunity. You're almost certainly not getting the improvement that you paid for.
  2. This was more of a general comment, not so much about this year vs last year.
  3. It's not just the grille fabric but also the frame itself. I've tested many different grilles (on/off) and there is usually a big enough measurable difference that the average audiophile could expect to hear a subtle to moderate difference. Most speakers measure better with the grilles off. I've heard and tested many Osborne speakers in different listening rooms. The room is the real offender here when it comes to bass.
  4. The main question is impossible to answer definitively without knowing how all your possible sub positions perform (with measurements). Without some very specific information, it can go either way. Around half of the rooms that I test perform well with just one sub. I recommend one sub where none of the useful positions offer a significant advantage. In this situation, it's better to choose a single better quality sub. The other half of rooms that I measure typically fit into two main groups: 1. Those with no single position that performs well, where a second sub is actually essential. In this case, the decision is easy. 2. Those that can benefit significantly from a second sub, often due to aiming to optimise more than one seat. Here the decision is not so clear cut. SVS SB1000 are value leaders and impressive in what they offer for the price. But they are built to a price and 2000 series and even many of the older models are cleaner and more accurate. This topic of 1 vs 2 comes up every week. Often the take away is "one sub is fine for my room." WAIT! Not necessarily! I think I'm overdue for an article covering this topic properly. A mistake that many people make is buying two subs because they've heard they are better. I've tested so many systems where two actually performed worse. The benefit is not automatic.
  5. SVS and Rythmik tend to use multiple ports that are driven by commercial considerations. One is the need for a product they can sell in reasonable volume - hence they can't be too big. The other is that the bigger part of their market like the option of tuning below 20 Hz. So you might plug one of the ports to get sub 20 Hz tuning. What this does is move the peak in port velocity down lower. What works for 15 Hz tuning with a 16" driver is probably pushing your luck with an 18" driver tuned at 24 Hz. Both the higher tuning and larger driver mean you need more port area for similar performance. Keeping in mind, SVS typically represent sensible design compromises. In an overkill style DIY project, it's a good idea to try to go that next step. Of course, you'll quickly find you hit hard limits, where your ports no longer fit or you simply don't want to make the box any bigger. And this is where you start to understand why some people use passive radiators! A single round port outperforms all other options with the same port area. When you move to two smaller round ports, you have increased the surface area and there is a penalty in performance. With slot ports this is generally a greater compromise, so you need greater area for the same performance. Hence longer ports. Slot ports have thicker walls and therefore also result in a larger enclosure. But they do have practical advantages, like avoiding making the baffle larger to fit large ports and also the way they can integrate with the bracing. Further, you can create some very large flares on each end - much bigger than you can use if you're using a router bit. Each have their place and if you're building it, you will also have preferences around how it goes together. In the example above, it looks like a pro audio music sub, probably tuned an octave higher with higher SPL to mask any port noise. In a home theatre sub, an unflared port like that limits you to around 6 m/s port velocity. When you find your ports starts chuffing at about 90 dB, that's not a happy moment! By far the most difficult is a home theatre port with a high excursion driver and tuning around 20 Hz. Music tends to mask port turbulence and excite audible effects much less than LFE effects on movies, which can happen at quiet points in movies.
  6. Nothing like an overkill project! You probably don't want to hear this at this stage of your project, but the ports will limit the output given their size. In fact, it's possible that turbulence could limit the useful output to less than you would get in a smaller sealed design. A large box with ~18mm MDF or ply needs considerable bracing and this can get tricky when using dual bend ports! Large panels need to be braced in the middle with braces that connect opposing walls. You also need your bracing panels to be braced by each other. If you brace it well, then you need to plan your build sequence with the ports. Now is a great time to buy a dolly if you don't have one and figure out your journey from the workshop to the HT in terms of ramps.
  7. There is an inherent challenge in answering the main question. If we try to form an opinion based on subjective experience, we are comparing more than one thing at a time. How often do we compare the same speaker in a wide vs narrow version? If we really wanted to know the subjective impact of baffle width when all else is equal, it would take the kind of rigorous comparison that is almost never done. If we were serious, we'd take a given passive 2 or 3 way design, with a wide and narrow version and the same tuning. Crossovers would have to be matched quite closely. We'd also have to level match and compare them double blind with a short swap over time. Sounds like a bit of work doesn't it?! And what is the result of all that work? I haven't done this particular comparison but I suspect that many would find this listening test a little confronting. In the sense that you have to resolve the disconnect between things you are certain you can hear sighted, and what you actually can hear when put to the test. I suspect in this case, if the speakers were closely matched in response and level, the differences would be too small to identify. In my experience, the ability of a speaker to image well isn't easily predicted on the basis of baffle width. Imaging is a trick that wildly divergent designs achieve. Ideas like "narrow speakers image better" tend to catch on because they are simple and intuitively they feel like they should be true. Simple and intuitive ideas are easier to market and they tend to spread around easily. I think this is why so many of them are so persistent. The question of wide vs narrow does lend itself very well to a DIY experiment with a DSP crossover and some knocked together cabinets.
  8. Results with DEQX vary from amazing to awful! One of the plots showed a gradual roll off we usually see in a room, which is about 10 dB down at the top relative to about 100 Hz. This usually sounds fairly well balanced tonally and if you were "correcting" that with EQ to flatten out that downward trend, the results are usually nasty - forward, thin, bright, harsh. When you say "too flat" it can mean many different things. Is that above what you meant? There are two main factors here. One is where the drivers are located, which will alter the interaction with the room. The other is the frequency response - larger drivers may simply give you more sensitivity but less extension. Put these two things together in your room and you get a result that may be counter intuitive. You are probably dealing with a lateral depth mode (between front and back walls, along the axis the speakers fire). The good news is that when you resolve it for your chair, it typically also resolves the seats either side as far as that mode goes. In a very solidly built room, it's often not just about the bass but also the low midrange where you may have considerable stored energy. This is where broadband traps and larger absorbers with a decent air gap behind come into play. An average room is +/- 15 dB in the bass range and this room is in that range. I've seen much worse, although the frequency response is only part of the picture. On top of room modes, we also see SBIR, which is boundary interactions based on the offset of woofers to wall/floor/ceiling. Sometimes the speaker position that sounds best will have some SBIR dips that can't be avoided.
  9. Is this a why not project? Or is there a particular reason for using a passive filter?
  10. Yes, it can be difficult to make meaningful comparison with so much time in between - where differences are subtle. A number of years ago Roger and I sat down to compare 3 different passive crossovers for the PSE horn. Each crossover had cables set up for quick swap overs, so we could compare with 20 seconds in between. The difference was clear, with two equal steps up in price and sound quality. The biggest difference was in the treble detail and refinement, mostly related to using better caps. Typically the better caps both measure and sound different. Stepping up to Jantzen Superior the shape of the highs are often different, with more treble and subjectively, more detail. In my opinion, the difference is enough to make these kinds of upgrades worthwhile. Many will find they can appreciate the difference without the easier comparison in which you get a quick A vs B.
  11. It's not unusual to see that adding bass traps can make the frequency response look worse in some regions, whilst the waterfalls are improved. In these cases the waterfall correlates better with the subjective difference.
  12. It's an odd experience when I find someone referring to something I wrote that I can't remember. When you compare different kinds of subs, there are two experiences. The first is the easy one - your first impression before you've done the real work of integration. With any kind of horn, you tend to get this MEATY bass. There is just this thunderous raw limitless power and you tend to overdo the volume. Every sub has its characteristics you notice first but this first impression gives you the wrong idea, yet this is often the impression that sticks. The second experience is the one that really matters - how it sounds when you've integrated it properly and ticked all the boxes. There's a pretty big list of boxes before the bass is as good as it can be, but once you get there, something happens that is a surprise for most people. Most of the differences vanish. At this point, you can no longer tell easily whether it's sealed or ported. I'm not saying they sound EXACTLY the same but rather, they are much closer than people tend to think. With a horn sub, you have to use steeper crossovers as they behave badly outside their passband. If you don't deal with this, they sound obviously inferior to their sealed or ported competitors. The crossover is then the main cause of them sounding different in a comparison. In a fair horse race, you'd have multiple sealed or ported subs that can perform well at the same SPL. Otherwise the horn will just knock the others out of the park with dynamic range, whilst staying clean. The fun part of bass horns is they do so much with so little. MDF is cheap. If you are a DIY enthusiast, you have to at least build one!
  13. This is a very interesting point. I've thought for a long time the difference is partly due to the lack of social mores surrounding online interactions. Face to face - we've had thousands of years to figure that out. Online - we've had just a few decades. One of the problems with online forums is that people lack "skin in the game." When you post under your own name, your reputation is on the line and it can change how you behave. One of the first forums I signed up for required people to use their real names for that reason. I decided to do that across the board.
  14. Congratulations ... contact us to receive your bucket! (Thanks Dave) Deeply disappointing I know
  15. Terrified, petrified, mortified ... and I'll award a free audio grade pot to the first person to get the movie reference.
×
×
  • Create New...