8'' two-way any reason why not?

[gowa]

Re: 8'' two-way any reason why not?

Hi Jed,
Will you be sharing the results on the Alpair?

[Guest]

Re: 8'' two-way any reason why not?

Well, it's not Vifa or Audax, but you might consider this one:
http://www.madisound.com/catalog/pro...roducts_id=834

And....I have heard many 8" two-ways that sound very nice. Some of the objections are just folks getting too caught up in the technical, in my opinion. The listening, however, can be very satisfying.

Thank you Jeff... that's a nice looking driver; roughly 4mmm Xmax, poly cone, and good SPL.

Looking at that driver makes me think of a question I've had for yrs; I wonder why some of the drivers have very small phase plugs, and some really large ones... wonder if it has something to do with the amount of bass they desire from the driver???

GC

[Fred T]

Re: 8'' two-way any reason why not?

Hi Fred, please forgive me, I'm quite easily confused. What does "It was developed for bass use so I doubt its suitable for a 2way" mean exactly, in terms of measured/physical reality?
Are you unsatisfied with the high frequency on/off axis behavior, smoothness of roll off, etc? Are there anomalies in the possible xo midband region? Is the low inductive rise due to the copper rings problematic, etc, etc.? Could you be a bit more specific/less vague?
Just trying to learn, thanks.

cheers,

AJ

Hi AJ,I like the sarcasim, I guess I deserve it ,My bad .:o I made the comment after reading the description that it was designed for use in their 3way, without actually looking at the link to response plot.

Now that Ive had a peek,the plot appears to be smoothed somewhat but response looks respectably flat and extended enough to use in a 2 way.I think THEIL cross it over in the 400-500hz range using 1st order slopes so it would need to have smooth response for 2 octaves above this.


cheers Fred.

[Jed K.]

Re: 8'' two-way any reason why not?

Hi Jed,
Will you be sharing the results on the Alpair?

yeah, I looked for it on my computer and now I can't find it. I'll take some measurements of this little guy tomorrow. It has a very extended FR, but a hiccup at 2k if I remember correctly. Might not be an issue at all given the right box application/crossover. The HD was pretty clean as well.

[Jeff B.]

Re: 8'' two-way any reason why not?

Thank you Jeff... that's a nice looking driver; roughly 4mmm Xmax, poly cone, and good SPL.

Looking at that driver makes me think of a question I've had for yrs; I wonder why some of the drivers have very small phase plugs, and some really large ones... wonder if it has something to do with the amount of bass they desire from the driver???

GC

To work effectively a phase plug needs to be pretty close to the same diameter as the ID of the voice coil, it needs to remain fairly straight without taper for the full length of the cone's expected movement, and it needs to extend the full depth of the cone. So, the expected cone travel and the cone's profile will play a role in the phase plug's length and shape. Of course, some phase plugs may not be optimized at all. It has nothing to do with bass, rather it plays a key role in the upper frequency extension of the speaker.

Jeff

[gowa]

Re: 8'' two-way any reason why not?

Well, it's not Vifa or Audax, but you might consider this one:
http://www.madisound.com/catalog/pro...roducts_id=834

And....I have heard many 8" two-ways that sound very nice. Some of the objections are just folks getting too caught up in the technical, in my opinion. The listening, however, can be very satisfying.

Mad's Kit:

http://www.madisound.com/catalog/product_info.php?cPath=35_40_402_272&products_id=379

Any idea why the tweeter is on the bottom?

[Æ]

Re: 8'' two-way any reason why not?

Thank you Jeff... that's a nice looking driver; roughly 4mmm Xmax, poly cone, and good SPL.

Looking at that driver makes me think of a question I've had for yrs; I wonder why some of the drivers have very small phase plugs, and some really large ones... wonder if it has something to do with the amount of bass they desire from the driver???

GC

The diameter of the phase plug is pretty much determined by the diameter of the voice coil. Big voice coil, big phase plug.

[johnastockman]

Re: 8'' two-way any reason why not?

Is there anything wrong with building an 2-way with an 8'' woofer. They seem to be frowned upon. I was at a get together last week where I mentioned that I was thinking about building a TM with an 8'' woofer and I got 'no, no, no, you don't want to be doing that'. It will sound awfull. I didn't have time to persue the subject because we were all getting ready to leave. So, what are your thoughts?

I've built two pairs of Dave Tenney's Dayton 8 2-ways and the Dayton 8 MTM's. Like Steve said, very satisfying to listen to. I built a pair of 10" woofer 2-ways, similar to the large Advents, in '77 from a parts kit/measured cabinet drawing I got from Speakerlab. It was their S2 model.



These embarrassed the large Advents and other similar designs that used a 10" and 8" drivers in a floor-standing 2-way. The drivers were Peerless and the tweeter had a low Fs...crossed at 1500Hz, 3rd order. I don't have the XO diagram anymore, but I ended up making more of those S2's (well, just the cabinets) once folks heard the SQ compared to their retail counterparts.

John A.

[DS-21]

Re: 8'' two-way any reason why not?

IMO, there's no reason not to do it, though 10" or 12" 2-ways are better. (I am, of course, referring exclusively to dual concentric designs or speakers with waveguide-loaded tweeters, taking as a given that nobody concerned about high fidelity would consider a different path.)

Great idea but what always bothered me with this approach is that off axis response above 5KHz is really poor. The speakers never have that disappear effect in the room because all the harmonic stuff is very directional. Of course saying that I have never really tried to do it for this reason maybe it would work better than it appears.

The augmented widebander approach has problems up top, yes, but that is a considerably better problem to have than the typical under-engineered 2-way, with a crossover smack dab in the midrange between two drivers of widely varying polar response in that region, one of which a flush-mounted tweeter that sprays all over the place at the bottom of its range.

That Theil woofer is an oem of the Vifa P22. Great woofer.....

Upgraded with shorting rings. Still strikes me as a poor value compared to, say, the Peerless HDS line.

[gowa]

Re: 8'' two-way any reason why not?

[jasont]

Re: 8'' two-way any reason why not?

So if we're lucky enough to find an 8'' woofer that can extend to about 2K, that would be good?

or you could use a pair of these crossed over at 750hz

http://www.mark-daniel.com/Dir_En.asp?Proid=13

[jonpike]

Re: 8'' two-way any reason why not?

I always thought that too, but when I finally got to hear the Linkwitz PLUTO (which uses a 2" tweeter) I moved around the room a lot trying to observe the "deficiency", and could not identify it in any reasonable listening area. Way off to the side, yes . . . but as long as I was between the speakers I couldn't hear any problem.

Ah, I was going to bring that Aura 2"er up. Someone else was talking about a large woofer 2 way, I looked it up again. It seems to have a pretty good FR, crosses quite a bit lower than most tweeters... and Sigfried likes it. It must have a pretty good diffusion profile as well.

[gowa]

Re: 8'' two-way any reason why not?

or you could use a pair of these crossed over at 750hz
http://www.mark-daniel.com/Dir_En.asp?Proid=13

Well, after seeing those tests results, I think I'm out of the running for those M&D's. I've been searching for a larger tweeter. Anyone know where I could find one?

[Guest]

Re: 8'' two-way any reason why not?

I always thought that too, but when I finally got to hear the Linkwitz PLUTO (which uses a 2" tweeter) I moved around the room a lot trying to observe the "deficiency", and could not identify it in any reasonable listening area. Way off to the side, yes . . . but as long as I was between the speakers I couldn't hear any problem.

That's one reason I'm hooked on the "wide angle" tweeter faceplates... with dispersion/imaging very similar to a cone tweeter, and the advantages of a dome. The very small semi-horn (Vifa style) faceplates do very well also.

GC

[scottsehlin]

Re: 8'' two-way any reason why not?

http://www.parts-express.com/pe/show...number=264-807I've been thinking about this as a possible "tweeter" for a large two-way. Efficiency is high enough to make it viable with many 8-10" woofers once baffle step is accounted for. I think you would still want the woofer to play up to 800 Hz to 1kHz.