Originally posted by 7_V
I like their choice of using the 5" driver to handle the 150Hz to 5,500Hz range (for reasons already discussed).
Also, an 8" bass driver is perfectly adequate for most purposes. There's much nonsense talked about bass drivers. Some people say that you need 12" drivers to produce decent bass and other such rubbish. The truth is that bass is about moving air. A smaller long-throw driver like on these Parsifals or W-M's Meadowlarks or a certain (highly respected) British company's Little Awesomes is often as good or better than a 12" driver which doesn't have such cone excursion. It will probably take a much smaller box too.
Yes, shame about the reflex port. Of course it's a matter of personal taste but I prefer a sealed enclosure or a transmission line. They tend to be easier to get right, easier to place and less liable to emphasize particular frequencies at the expense of others. I think that the transient response of a sealed box is better too. Does this make me a flat earther?
It's also a pity that the mids won't stretch that extra 1/2 octave (approx) and play to 100Hz. This would give you the freedom to move the bass unit away from the mids.
Steve, with regards to the drive unit employed by Verity, you might like to look here
http://www.flexunits.com/
The unit in question is manufactured by Audio Technology in Denmark. Formerly known as Skanning, these are quite exeptional units, considered by many to be the finest the industry has to offer (yes better than Bandors
).
Few companies can afford to use them in commercial products, although Verity are joined by Peak Consult and Rockport here. The old Sonus Faber Extrema also used a Skanning midrange unit. Per Skanning's father was the founder of Scanspeak and Dynaudio so there is pedigree here. All the speakers I have heard using AT drivers share a quite superb midrange.
Now as for the rest of your post, I'm afraid it suggests a limited grasp of the effects of cone distortion and power handling to me. Starting with your assertion that an 8" drive unit is every bit as good as larger units with less cone excursion, this is simply untrue. Yes bass is about moving air, but with long cone excursions, the likelyhood of decreased linearity and hence increased distortion is high. Very high cones excursions are neccessary with these units to create adequate SPL's at low frequencies (due to the amount of air that needs shifting). Increased distortion is the unfortunate byproduct. Using a large cone area to generate bass allows for less excursion, greater efficiency and and usually higher SPL's. The only drawback is an increase in moving mass, but with high quality doped paper cones and large lightweight voice coils, (which don't require extensive stiffening due to the relativly low excursion) , this is no longer an issue. Larger cone areas will also drive the room better at low frequencies, given their closer approximation to the wavelengths they are attempting to reproduce.
Yes, shame about the reflex port. Of course it's a matter of personal taste but I prefer a sealed enclosure or a transmission line. They tend to be easier to get right, easier to place and less liable to emphasize particular frequencies at the expense of others. I think that the transient response of a sealed box is better too.
As you are fond of saying, it's all about compromises. And, with attention payed to controlling group delay in vented enclosures, they can perform well. If anyone can explain to me how you can get high SPL's at low frequencies from a small drive unit in a small sealed enclosure, I would be interested. Room interaction is certainly less predictable with ported enclosures I agree, but here a little tweaking should give good results.
It's also a pity that the mids won't stretch that extra 1/2 octave (approx) and play to 100Hz. This would give you the freedom to move the bass unit away from the mids.
If you have read the specs on the 5" AT driver, you will see that it's capable of going down to 42hz. With any drive unit, you will get better distortion figures and greater power handling by not driving it full range. Most of the world's finest speakers employ drive units that operate over a small percentage of their published bandwidth. Take a look at the Avalon Eidolon and the JBL 9800 K2 for just a couple of examples.
This brings me to my point. You drive the Bandors full range. Additionally, you choose to use small bass drivers in compact sealed enclosures. The drawback to this approach is outlined above, namely low power handling and maximum SPL. From speaking to some who have listened to your babies, this appears to be a critisism. For small scale work at sensible levels, your approach is probably excellent. But I would be surprised if they were able to bring the ceiling down a la WM. I would use a sharp HP at about 275hz on the satellites, and employ sorcery to integrate the subs below that, with a HP in the sub at say 30hz to reduce distortion.
But as you say, it's about compromises.
Cheers
as you can use any crossover frequency and any slope you like (merlin uses 10th order I think). Certainly worth considering, as long as I get to keep the drive and life I get out of my system atm.
