A friend of mine is outfitting a home theater and the speakers are falling to me to decide. Given the budget and goals we have settled on going with bookshelf size speakers all around, matched to 3 or 4 Peerless XLS 12" subs. So I rounded up some drivers and set to work on some designs and thought I'd share what I found. This all very subjective, so don't shoot the messenger, and keep in mind it is only my own perception and tastes expressed.
The woofers are the Zaph ZA14 and Scanspeak Discovery SS15. Tweeters are Peerless HDS, Dayton RS28A, SEAS T25C001, and Vifa NE19VTC. Since there are some very good commercial designs in this price range I picked two: the Wharfedale Diamond 10.1 and Kef Q100. Actually the Kef was not the retail speaker, but the raw driver, more on that later. The DIY designs all used the Dayton .38cf cabinets with the same driver layout so baffle diffraction would be the same. I used the minidsp for crossover work, and I have to say this is an invaluable tool for prototyping and quickly comparing changes. The other key thing is these are comparisons between single speakers in mono, since I would need 4 of everything instead of 2 of everything to do direct A/B comparisons if I wanted to do it in stereo. I'm not sure how listening in mono may change the sound, so keep that in mind. I used a 2khz crossover for the RS28A, HDS, and T25C001, but as I've found in the past I like the HDS a bit higher, so it was at 2.3khz for the final reviews below. The NE19VTC was at 3khz. I've also been doing final voicing on my Bosebuster v2 during this time and those made it apparent the NE19 likes to be crossed a bit higher than 3khz to get the cleanest sound. The grittiness or spittiness goes away very quickly above 3khz and I'm finding 3.3khz-3.5khz is probably the sweet spot. Anyway for this comparo matched with the SS15 they were at 3khz, so there are some improvements to be made later. For the Kef I used a LR4 2.5khz crossover to match the retail speaker. Where they might differ is BSC. I basically matched all the speakers to be basically the same, about 4db of BSC. I've heard the retail Kef can sound a bit lightweight, so it is possible they use less BSC, and they may not sound exactly like my version. All speakers were level matched from 200-10000hz.
I started with comparing the HDS/ZA14 versus the HDS/SS15, so basically just comparing the woofer. At 2khz these sound near identical, I mean it was really hard to pick out a difference. And this is even with turning off the tweeter to just listen to the woofer, a very enlightening thing to do, especially with tweeters. It really helped to narrow down which driver was misbehaving at times. I would find later the differences between these woofers become more obvious as you go up in XO frequency, with the ZA14 getting a bit forward and shouty by 3khz. But at 2-2.3khz, near identical. After a lot of switching back and forth my impression was that the ZA14 was just a touch more composed in the middle/upper midrange, and so this is the woofer I used when comparing the HDS, RS28A, and T25C001 to each other. Both ZA14 and SS15 had refined if not voluminous bass. Both stayed pretty composed when the cone really got moving, with maybe a slight nod to the ZA14 for being better behaved, but this is probably not much of a distinction since they both were well behaved right until they started bottoming at about the same point. So with the woofer decided on to the tweeters.HDS/ZA14 vs RS28A/ZA14
I felt the RS28A was very clean and clear, but a bit more forward and harder or "clinical", while the HDS was more open, natural and spacious - vocals and many instruments just sound more real and present. The RS28A is very well behaved, probably more than any other tweeter I've used since the Scanpeak 9800 (which I've heard was the "inspiration" for Usher when making the RS28A style tweeter). The HDS will occasionally misbehave: there is some area on the low end of its range that will occasionally jump out at you. Not crossing too low helps a lot, but I really need to get around to using a waveguide to see if I can finally solve it, because to me the HDS is otherwise the best sounding tweeter here. Still both of these are very good tweeters, and if it sounds like I'm being a little hard on the RS28A with it being a bit harder or forward, it is only in comparison to the HDS in quick A/B switching, it is not a hard or forward tweeter in an absolute sense.HDS/ZA14 vs T25C001/ZA14
These tweeters sound REALLY similar. In the end I felt the HDS was just a squidge more natural and spacious, while the T25C001 was a better behaved in that area the HDS isn't, but a bit harder and less spacious. I don't want to overdo the differences here though, they are very similar. If I can solve or just accept the occasional HDS misbehavior I'd go with it, if not the SEAS is probably the least troublesome pick while sounding much the same as the HDS in all the ways I really like about that tweeter.
I also compared the SS15 with the above tweeters versus the ZA14 versions, but as I said there just isn't much difference at this crossover point so I won't bother with any impressions. Now that I found a good combo in the HDS/ZA14 I compared it to the Kef Q100.HDS/ZA14 vs Kef Q100
This Kef is sort of a heartbreaker. It does some things SO well, and than it falters a bit. First the midrange and lower treble are really good: coherent and solid. Nothing wanders back and forth between tweeter and woofer. More forward than anything else here (due to the solid upper midrange and possibly the directivity), and most of the time this was a good thing: vocals are very clear and real, solid. Instruments in that area are similarly clear and solid. It was really very different in presentation from the other speakers in this regard. Usually a big, solid image. But...the forwardness could really get "in-your-face" at times. The tweeter is a bit rolled off in the "sparkle" area, and can get gritty when pushed. The treble is unrefined compared to most others here. Imaging is very good, but spaciousness was not that great, it could often sound small and speaker-like for lack of a better term on some music that didn't have much content in that prominent upper midrange area. Besides a bit of tweeter grittiness, it could also get congested and closed or "hooded" sounding. The HDS/ZA14 in comparison was more relaxed and refined. More spacious and more "3D" like imaging. More musical and forgiving. If it sounds like the HDS/ZA14 was hugely superior speaker, well it was, except in those areas I noted on the Kef, where it really was no comparison. I think if the Kef woofer breakup could be better controlled or brought down in level, and the tweeter brought to the level of some here, its weaknesses would melt away and you would be left with a very clear, and realistic sounding speaker with big, excellent imaging. If appears the Kef LS50 made improvements in exactly these areas, and they may very well be the speaker to have, doing some important things much better than most DIY designs.HDS/ZA14 vs Wharfedale 10.1
The first thing I noticed about the 10.1 is how "immediate" and "present" it was. I really like this in a speaker. Combined with a warmer character the music is very involving and enjoyable, just pulling you in. Percussion was very clear and lifelike, the shimmer and sparkle regions are prominent and pleasing. Total lack of sibilance. Overall a very pleasant, well behaved speaker. Except...a hint of constant graininess in the treble. Nothing that ever really annoys you, just overall not as refined and clear as teh HDS, RS28A, or T25C001. Could get a bit congested and honky on more complex material or higher volumes. Sounded smaller and more speakerlike in comparison to the HDS/ZA14. The HDS/ZA14 on the other hand was simply smoother, more refined treble. More spacious and bigger image. Cleaner, calmer, and more composed everywhere. The bass stronger than the 10.1, and much more refined, the 10.1 could get a bit flabby in this area. On the other hand it lacked that immediacy and presence of the 10.1, sounding more detached and colder, maybe harder, and so for all its refinement and clarity, it lost some emotion and musicality to the 10.1HDS/ZA14 vs NE19VTC/SS15
I must say the NE19/SS15 combo surprised me. But then I made this speaker because I suspect that sometimes the push to lower tweeter crossovers to better match woofer directivity results in a less pleasing speaker,and I wanted to test this out. The problem as we all know is the prominent dip/hump in the power response with a typical speaker. IMHO waveguides are the way to solve this, but the fact is this is not very realistic for most DIY'ers, or at least common yet. Sans waveguide, I'm not always convinced pushing the tweeter lower is always the best way to deal with the dip/hump. Often the speaker can become forward and harder. I suspect it may be because we still have a hump, but now we are pushing it down into the 2khz area where the ear is very sensitive. I wanted to push that hump up in frequency. There will be other tradeoffs I think, in clarity and other aspects, but I was betting the overall sound be a pleasing speaker, versus a clear but hard one. And that is pretty much what I got. They ended up having close (but not quite) the same immediacy and presence of the Wharfedale, similarly lush sounding, though I wouldn't say too warm. Just a musical, involving, pleasing speaker, that pulled you in. The HDS/ZA14 in comparison sounded more distant, and sometimes "flatter" somehow, less involving. OTOH it had a bigger and more 3D soundstage, with smoother and cleaner treble.NE19VTC/SS15 vs Wharfedale 10.1
The NE19VTC/SS15 was like a Wharfedale 10.1 on steroids. Presence and immediacy are almost (but not quite) as good as teh Wharfedale, but with a much cleaner midrange and treble. More spacious and 3D than the Wharfedale. And the bass of the SS15 was much stronger and more refined. While the Wharfedale always has that immediacy and warmth, in comparison it just sounded smaller, chesty, grainier/hashier. Better bells and sparkle on the NE19VTC also.NE19VTC/SS15 vs Kef Q100
Again the strong points of the Kef, coherent, solid midrange/lower treble, solid imaging with usually big lifelike image (when content is in that upper midrange/lower treble area) are pretty unbeatable. Clear vocals are usually another plus. The NE19VTC/SS15 just doesn't have the coherence or forward-ish clarity. But its overall presentation was more relaxed, more musical, mostly better refined treble. Doesn't congest and instruments sound more pleasing. Vocals are not as big and clear as the Kef, but often they are more pleasing.
So takeaways...if I could have the coherence and prominent/solid midrange of the Kef, the immediacy and presence musicality of the Wharfedale or NE19VTC/SS15, and the overall refinement and clarity of the HDS/ZA14, well that would about be the perfect speaker. I think the DIY speakers acquitted themselves well, but the retail designs did some important things very well too. I could see someone else listening to these same speakers and - other than the more refined and cleaner treble/upper midrange of the DIY designs - really liking the retail designs for their strengths. In this price range, I could easily recommend either the Kef or Wharfedale to friends or family that wanted to buy a very good speaker for a reasonable price. And they are good speakers, at this price ($350/pr
for the Wharfedale and $450/pr
for the Kef) it is hard justify spending about the same money and getting covered in sawdust for a not hugely superior DIY design.
The NE19VTC/SS15 combo was a very pleasant surprise. I have a couple waveguides from Dave P. that I want to try to see how well behaved I can get that NE19VTC. I also have the new RS150P on the way and intend to see if it can replace the SS15 sonically. If so a NE19VTC (with or without WG) and RS150P combo could be a very enjoyable and cheap design, even if it is not quite as refined as the HDS/ZA14. I would like to hear some Kef LS50's If they can improve on the slight weaknesses of teh Q100, they could be VERY VERY good. I'm also almost done auditioning the different NE19 versions on my Bosebuster v2 design and I'll post those differences soon. I'll have the Kef Q100 drivers and Wharfedale 10.1's (only took one out of the box!) on sale soon in the classified forum