Originally Posted by kryptonitewhite
lbaccoustics, Your center channel and the outter L/R speakers look somehwat like the Adire Kit LCRs I based my front stage on. The inner L/R speakers you are posting about look more "pro audio" to me. Same or similar tweeter, but rather than 3 way with the midbass being small compared to the woofer on the 2 way, and the cone woofer looks like thin paper vs thick poly for the 3-ways. Hard to tell from the pic.
Jack Bouska's ultimate speaker looks like it could/should suffer from a little bit of comb filtering? It is the inverse to myt front stage, I have 4 midbass in the center, 2 midrange, the 4 tweeters spread in a strait line 49" wide looking very similar to "ultimate speaker ".
Jacks speaker, like all d'appololito designs will suffer the reality of comb filtering - no doubt, this is a phase issue and is manifest as a slightly wobbily FR depending on the position you are listening from. The advantages of the design are that you can decrease all areas of distortion at any given output level, and also increase the headroom by 3db. The question is- how audiable is comb filtering? - as im listening from 4m+ away, the problem of comb filtering is much less for me, so this is an answer I dont feel I need to address in my home. (thankfully!) Spacing the drivers as close as possible is still a priority though.
The speakers on the outside of the photo are Troels Gravesens tjl3w speakers and use the one and only seas excel magnesium drivers and a hiquiphon ow1 tweeter. -they are good speakers, but the application is wrong for me. It took me a long long time to realy get a grip on what was realy wrong with these speakers and the answer is that its nowhere near optimal for the environment I use it in or what turned out to be my personal tastes. In fact, I could argue that it would be the wrong speaker for most environments.
I would imagine there are one or two who would read the last paragraph and think I was just plain wrong. How could such a perfectly measuring speaker be no good? everyone knows the seas excel drivers are some of the best money can buy ... right? Well, please read on and learn from my mistake!
The tjl3w's are maxed out at under 100db at 1m, the tweeter is the limiting factor and so this cannot be 'fixed' with crossing over to a sub. The speaker is 85db@1w so its rather ineffecient. This inefficiency cannot be overcome with power (that is a parasound halo a51 in the pic) because the more energy you introduce, the less efficient the driver becomes (power compression) and what happens is that you just dont get life and dynamics from the music! On top of that, there comes a taste factor- I like low qts drivers - plain and simple, a driver needs to be tight and not boomy. I appreciate that the box alignment and implimentation is key in getting this right, but for me sealed sounds wrong generally for me (so far!) and drivers that control there own movement sound closer to real. I can only apply this absolute to bass drivers as I havent had the chance to realy see what difference this makes to mids.
Basically, the tjl3w's lack bite when needed and are far too output limited. They are however realy quite special when brought close in to 1m- very detailed and spacious- but this only confirms the problems ive listed as the volume needed is very much lower at this distance.
Looking at lbaccoustics links, the pro audio light paper coned accordion surrounded driver has a beastly motor and spider, a trend I have been noticing as I start to look at these other drivers that have an inferior appearance to me. Maybe this is where my misconceptions began, the fronts of the drivers look old fasioned, light weight, while the back side is beefed up...hence the high efficiency and warm sound?
The pro audio speaker has some very nice features that are not appreciated when you look at them. They go very loud cleanly, and although they have very limited bass and are ugly believe me when I say they are special. That tweeter is massive and by far the heavyest tweeter ive ever held. The waterfall graph of it shows just how good it is-http://www.troelsgravesen.dk/TW034.htm
have a look at the impulse graph- tight no? These fabric tweeters have very little energy storage.
The bass driver is a paper coned heavyweight monster that surprisingly has quite a stiff cone and lots of headroom. Unsurprisingly to my ears, qts is a mere 0.2 - tight as a badgers arse. I dont get the 'airy' magic that seams to come from pistonic drivers like the excel units, but I get drama and dynamics in spades- but without too much loss of spacious 'out of the room' sound because the cone is still stiff- just damped well.
You mention 'warm sound' - Many paper drivers are indeed warm sounding.... but unfortunately this is actually a bad thing imo. It may sound pleasant, but its the sound of breakup where the cone is deforming in shape as it tries to keep up with the music waveform. This bass driver doesnt sound particularly warm. I can tell its paper- sure, as all cone materials have a signature of some sort ie -they break up in particular patterns. Many paper drivers (particularly full range) break up at all levels because in order to get the bandwidth of the driver so wide, the cone needs to weigh next to nothing therefore its as thin as possible- hence the particularly 'warm' sound.
. I dont particularly want to push any of my drivers anywhere near there limits for this reason (among others). Hopefully you can begin too see why I would consider Jacks design to be close to optimum for me.
To my ears, the speaker sounds a little forward- a negative that I associate with using a 10 inch bass driver all the way up to 1k+. The sound changes in the mid as I walk around the room- this is basically beaming and power response related so again somthing I would look to solve with adding a mid driver.
Could you post a pick of the adire speakers you mention?
LTD02's pics have the HT look... shiny plastic thick looking cones, thick rubber surrounds. Does this decrease efficiency?
Hope I didn't bother you too much with my OT... popping in to say i am watching your thread and hope to learn from it!
Not in itself no. But as a generalisation - yes the majority of designs that have this aesthetic quality are lower efficiency yes. Cones are like cars- you only need 200hp to overcome the innertia of a aluminium kit car for some serious speed, but you would need 2,000 hp to make a hummer realy shift. The stiffness to weight of the cone is very important, thats again why the seas magnesium drivers are so good- magnesium is very stiff- but its still to heavy to shift! Berlyium is the ultimate in this area. In reality, its not that simple though- The reality is that the cone, however hard -will deform-(brakeup) and when this happens, the harder and less damped the material, the worse it sounds. Play a typical cheap 1 inch aluminium tweeter too loud or low and you will know what I mean. This brings you back to paper- its very stiff for its weight, but the breakup is almost pleasant!.
ps- OT all you like as long as it benifits someone, its all good!