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In the Forum: Melquiades Amplifier
In the Thread: 5 Channel Version of Melquiades
Post Subject: No problems with necessary powerPosted by Romy the Cat on: 8/9/2006

 jessie.dazzle wrote:
Upper Bass : Frequency range between 100 and 500Hz – Driver loaded into a 120Hz straight horn, driven by DSET dedicated channel.
 
Mid Bass : Frequency range between 40 and 100Hz – Driver loaded into a 45Hz straight horn, driven by DSET dedicated channel.
 
Lower Bass : Frequency range under 40Hz – via a pair of large direct-radiating woofers in sealed enclosures - driven by a pair of 100 watt hybrid monoblocks (Lamm M1.1s).

Hmmmmm, I would say that looking at the upperbass channels it would be important to know where and how your MF driver stop. Would it be 500Hz, 750Hzm 1000Hz,? The Slope, how good they will be at their lower knee? It is all very important. I do not feel that it is possible to think about the system architecture without looking what a specific driver does in the specific condition. 120Hz straight horn is a good thing but why 120Hz? Also, the 40 and 100Hz? It might be also the 40-150Hz and 150Hz-800Hz. It will be all depends the driver you use and the physical excursion of the bass horns and your ability to position them. Still, what you are planning to do it very commendable and very noble…
 jessie.dazzle wrote:
Based on the info in the thread “Exceptional loudspeakers drivers: 18-inchers”, I would of course like to try the Aurasound 1808, but I am not at all sure I can find a pair of the original model… In that same thread, you mention the 833A tube could possibly be used to good effect in a DSET channel driving such a woofer… ultimately, I would like to consider this solution, in which case we would be talking about a 6th channel. For now however, I think it would be best to take things one step at a time, and leave this channel out of the DSET, driving it with the M1.1s (I don’t mind building a second version that integrates a lower bass channel, but would rather leave that for later).

Well, if you do not go for LF driven by SET then your DSET amp will be relatively simple. You would not need any crazy transformer or PS. Two tips. Do not literally follow the “Exceptional loudspeakers”. I am sure in your part of the world it is possible to find the similarly good drivers. The second tip, and I ma not kidding: forget about the lower frequency channel. Make the horns, get good Sound and THEN add the LF channels. With proper 40Hz horn you should be a able to get very good sound and the LF channel will be a assessed on context of all together well balanced and performed system. I sincerely fell that it you have all horns made and amped then you would need at least 6-mouth until it would make sense to bring the LF channel in the picture.
 jessie.dazzle wrote:
Room dimensions : The “room” is actually a sort of loft; the main room plus immediately adjoining areas total to around 400 ft², with ceiling heights varying from 8.25 to 16.5 ft. for an average of about 12 ft, which works out to about 4800 cubic ft. How does this compare with your room? In the case of the Upper-Bass channel (100-500Hz) : The driver can handle up to 100 watts, and has an efficiency rating of 101db/w/m. I assume 20 watts would be adequate. In the case of the Mid-Bass channel (40-100Hz) : The specifications regarding power handling and efficiency of the selected driver (Vitavox AK151) are not clear; the manufacturer says power handling is “determined by the associated horn characteristics”… In any case, 20 watts should not be too much for this driver. You are right, the real question is: Will 20 watts be enough? I had planned to answer that question by connecting a pair of ML2s to the horns, but am having trouble finding a seller (early version ML2) who will ship to Europe.

Wow! The 400 sq feet is a good small room. It is not a critical size and the amplification you are trying to use with your speaker will be just fine. You will be getting for horns approximately more then 5W-6Wm considering that your horns do +6dB gain. There are many other variables (for instants now ‘live’ the room is) but I still would not worry of the lower channel will not be driven by DSET.

Rgs,
Romy

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