Herman, what driver is used in a Lamhorn ? Is this a Lowther based unit or something similar ? I've read about them but can't remember the specifics.
I forgot to add that the single full range driver that i'm using will reproduce a 5 Hz signal up to appr 17 Khz tone with reasonably linear amplitude. Unlike most "full range" drivers, it can and easily does shake the floor with great authority. I found out about the "5 Hz response" when playing the Ayre Acoustics disc that was mentioned in another thread. The Cardas sweep tone starts out at 5 Hz and progresses up from there. Needless to say, i was amazed to see the driver responding at all let alone easily throwing back and forth at that rate.
In terms of frequency response irregularities, room loading is probably responsible for most of that. You see, this driver radiates in a 360* horizontal pattern so cancellation and reinforcement become critical in terms of measurable frequency response and output levels. Before you consider the omni pattern and room loading characteristics a drawback, take into consideration that it also produces the widest and deepest soundstage possible. Not only that, it also reproduces notes in a fashion that resembles most acoustic based instruments.
There are four major problems with this design:
1) It takes a very muscular amp to get it moving and keep it under control. It operates at under 2 ohms at very low frequencies. As such, you need an amp that is very low in output impedance in order to maintain a reasonable damping factor. You also need an amp that can produce sustained amounts of high voltage and current to keep the driver under control and deal with the higher than average amount of reflected EMF.
2) It is definitely limited in terms of absolute SPL and dynamic range. Some may say that it plays plenty loud ( fans of chamber music, mellow jazz, acoustic recordings, female vocalists, etc... ). As such, the more that you increase the average listening level, the less dynamic range you have above that point. In plain English, the driver will go into compression on peaks. It can play rock and very dynamic classical recordings so long as you don't ask for extended periods of high listening levels. If you do, the driver begins to produce signs of distress.
3) Since the speakers are in-efficient and a tough load to begin with, you need to throttle them with power to get reasonable SPL's out of them. If you try to squeeze a little more out of them, not only is it pretty demanding of the amp, the driver begins to saturate, overheat and "warble" profusely. As such, you have a somewhat limited window of operation with them.
4) The drivers are no longer made. As such, it is tough finding someone to work on them and do it right. This obviously tells you that they should not be abused in the least if you like them and want to keep them around for any amount of time.
With all of the above taken into consideration, if one can live with listening at low to medium levels, they sound fantastic if fed a high quality signal. After all, there is nothing to get in between you and the sound made by the system in terms of coils, capacitors, impedance compensation networks, notch filters, time and phase delays, etc... that one finds in many "high tech" speakers. The low volume constraint really isn't such a big deal, as it is one of the few speakers that maintains tonal balance regardless of listening level ( so long as you're below the point of saturation ).
All of the "good points" about this design FAR outweigh the "bad points" mentioned above. That is why i own two pairs and have publicly stated that i will never part company with them. Sean
>