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Red Spade Audio

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  1. Red Spade Audio

    DIY JBL Clones

    2 way makes a lot of sense for this kind of speaker.
  2. Red Spade Audio


    With the PSE-144 horn, the tweeter and mids share the same horn and their outputs combine at the throat. These two bands then share matching radiation characteristics. In some ways it does behave like a 2 way system. However, since a crossover is in place I'd still class them as a 3 way system.
  3. By "general focus" what do you mean exactly? Dipoles (including planar, ESL and open baffle speakers) provide two snapshots at the depth of the soundstage. The first comes from the direct sound that you get with any speaker. The second comes from the rear dipole reflection off the front wall that is phase inverted, reduced in SPL and delayed in time. That gives a deeper sound stage and a little more freedom to move your listening position sideways without having the sound stage collapse into the nearer speaker. In this particular aspect, different dipole designs may respond differently. The downside to all this is that the location of sounds within that deeper sound stage is less precise. I notice this effect most with voices, especially on movies. You might call it lack of focus and it applies most to depth. So you can treat the front wall in two ways. Diffusion and absorption. Diffusion not only enhances the depth, it also improves transparency and retains some ambience in the room. The effect can be subtle or dramatic, depending on the room. You can even hear it when you are simply talking in a quiet room. Mostly if you are a room acoustic nerd and you can't help but notice how a room sounds when people are talking. What you might find interesting is what happens when you add absorption to the front wall. This is a bit like a volume control on the rear radiation of your speakers. Effectively you are dialing it back. One trick is to do this when your wife is away and you can steal cushions, the kids mattress and try varying amounts and different positions. Diffusers are a very safe bet for dipoles but absorption you might also want to experiment with. You may or may not like the result and there is no better option than to spend some time listening, one change at a time, noting the difference. I'll be interested to hear your impressions if you try the above. Best of luck with WAF!
  4. Unfortunately all I have time for right now. CLD is not a panacea but that doesn't rule it out as a viable strategy. All practical loudspeakers involve a balance of compromises. My interest in this thread is to see if a product eventuates. Technical debates tend to take more time than I can spare.
  5. Yes. It won't surprise anyone that to make a speaker with CLD is never going to be entirely simple and easy. You say that as if you are replacing a difficult problem with an easy and simple one! CLD improves performance without an increase in weight.
  6. That's a fair point but you could use a mitre, lap mitre or rabbet joint - any of these would avoid that issue. The problem then becomes different - it's about whether you can machine the adhesive, as it would probably make a mess of saw blades or router bits. In which case a DIYer using a table saw might do a rabbet joint but set the blade height to avoid cutting through the adhesive, finishing the cut with a stanley knife manually.
  7. The box was designed as a base for an early prototype horn with a more typical pro driver. The TD18 magnet would hit the back of the bracing. Needs about another ~22mm plus a little more for a gap between bracing and magnet. Definitely worth trying TD18! Adding a 2x18mm baffle should allow TD18 to go into that enclosure, if you are surface mounting on the baffle. To flush mount TD18 you just add another 18mm sheet as the rubber gasket is around the same thickness. The volume is already more than you need. That's the quick way. But I'm guessing you probably want to build a new box anyway.
  8. Red Spade Audio

    Foam Bass Traps

    Thanks for the mention Snoop and blybo. Foam can actually work as a bass trap but in the vast majority of cases, they are simply too small. I've tested foam traps that work very well but the size required is well beyond what is acceptable in even most dedicated rooms. The most effective were around 2m wide! Just about any system can be improved with bass traps but not all bass traps will give you a real improvement. In general, when it comes to bass traps, there are three types of rooms: 1. Disaster - treatment is essential to get good bass 2. Well damped - great bass is possible without traps 3. Average - modest bass issues which probably won't get treated because they don't draw obvious attention to themselves
  9. A high density 1" version would be interesting to see.
  10. Just use an RCA splitter on one of the outputs. Dayton make a wireless sub sender and receiver which replaces a run of interconnect - this can be a problem solver for the cable run.
  11. Red Spade Audio

    The new "Listening Room"

    Putting an absorber behind a dipole would reduce the rear radiation, converting from dipole to a radiation pattern that might approximate a cardiod. You can do this with any dipole (ESL, Planar, dynamic driver open baffle) with a similar impact, however, most dipole owners actually like their spatial characteristics. As a long term Maggie owner, Andy is clearly in that camp. Adding absorption on the front wall or directly behind the speaker, subjectively speaking, reduces the sound stage depth which dipoles are known and appreciated for as well as tightening the focus of the stereo image. This would tend to favour some types of music over others. Classical music works particularly well with dipoles because they are the best speakers for making a room sound bigger than it really is. Ambience and spaciousness are then more important than getting a precise image. For Andy this would be a step away from his goal. When your wife accepts your big speakers, moving to small is a one way ticket!
  12. Red Spade Audio

    Speaker problems

    It looks like they have sprayed the entire front baffle, including the drivers and screws! You can see they have held the can too close and given it a very light and uneven coat. More than likely the paint will start to come off the screws when drivers are removed. The solvents used in the spray can will have an undesirable effect on the tweeter dome especially, along with the surrounds - these should never be painted. The problems you mentioned may have existed before this "renovation" in which case its owner may have simply hit it with a cheap spray can, thinking it would be easier to offload. I don't like your chances of getting any money back.
  13. Red Spade Audio


    Nigel, I tend to agree in context. Same place ... how long ago was that other little GTG? Welcome to swing by when you're in the area. When is the MotoGP?
  14. Red Spade Audio


    If we are talking about a low compromise system then I tend to agree but I would go one step further - 3 way + subs. If we're talking about conventional speakers, we then have four specialist drivers: 1. Tweeter 2. Midrange In moving beyond a 2 way system, now we have a mid with much less excursion and the design can be optimised for a smooth and extended response. Without the need for high excursion, we can have a surround which is now better optimised to control the cone edge. We can use smaller cones and we have various options to push breakup much further away from the crossover region. A dedicated midrange is clearly superior. In a 2 way system we are forced to use a general purpose midwoofer. Serious breakup behaviour is typically very close to the crossover region. There is a tug of war between the very different requirements of bass and midrange. 3. Woofer Free from the requirements of midrange, the woofer can be larger with higher excursion. So the woofer not only allows the midrange to do its job better, but it also adds greater depth and dynamic capability. Most people are happy to stop here and many will even find they get "too much bass" for reasons related to the room more than the woofer itself. 4. Sub A sub adds a few advantages I've talked about many times (including that SNA article I'm too lazy to link). For some it's the ability to get as much bass as you want, as deep as you want it in a box that might be smaller than a woofer. For others it's the ability to add EQ without upsetting one's inner audiophile with such things are ADA conversions and ..... *gasp* adding another DAC to your signal chain! Much sleep that you might have lost can be saved right here. And there is also the advantage of being able to put a sub in its most optimal location. This alone can mean a sub with no special magic qualities, can give you better bass than your main speakers. Maybe, maybe not. A further advantage (as if you needed any more) is the ability to create just the right balance of bass. A room curve much like the one that Harman found the vast majority of audiophiles actually prefer. You might get it with your 3 way speakers but often you won't. A sub creates the possibility of getting an ideal room curve in any room. But sometimes you get lucky. You might put a really nice 2 way into a room where the two fit together like a glove. And if you then were to plonk some 3 ways next to them, the results might be a surprise, contrary to everything I've just written. And adding the sub, could just turn it all into a gigantic mess that fails in spectacular fashion. The potential does not automatically translate into a blissful listening experience - it takes a series of good decisions and in the case of setting up a sub, skilled calibration.
  15. Red Spade Audio

    Subwoofer under 5k - mostly music

    Let me put it another way. It's a simple problem to find out your bank balance, even if no one else has access to that information. It's a complex problem to understand women, even if you're married to one of them for your entire life! Geddes developed a distortion metric, which he called the Gedlee metric. As far as I'm aware, it's never been used to evaluate subwoofers. It has a strong correlation with perception. The challenge with these kinds of measurements is actually making them meaningful. I believe there is a lot of research that could be done to advance our understanding but in general I don't see a push for this kind of work. Manufacturers don't typically like to publish measurements of their subs and consumers don't demand it. The greatest push for data comes from DIYers. It's an interesting question for sure but I don't have a short answer that won't derail the thread. But I will say one thing. The increased accessibility of affordable linear phase DSP devices now means it's more easy for people to start to investigate things like the audibility of group delay.