News: Trouble logging in? Log in from the login page.
March 24, 2019, 06:17:01 am

Author Topic: My big three way reference system is for sale  (Read 276 times)

0 Members and 1 Guest are viewing this topic.

Offline Doc B.

  • Administrator
  • Hero Member
  • *****
  • Posts: 7635
    • Bottlehead
My big three way reference system is for sale
« on: March 08, 2019, 09:48:56 am »
Alas, it is time for Doc to reduce the load around here again. I have decided to let my big speaker system go. This is a setup we built in 2008 as my reference speakers and we refined the design over many years. At the time I needed a system that could keep up with the likes of the top of the line Magico, TAD and Focal systems we were demoing with at trade shows, without spending $60K-$80K. I used the system for evaluation of Tape Project titles and the development of many kits. It is a three way system composed of RAAL 140-15D ribbon tweeters, ATD Hypergraph 130K midranges (I have two spares as well) and four Exodus audio 6.5" woofers. Each driver is in its own cabinet which stacks with the others and allows shifting fore and aft for time alignment to a given listening distance. The cabinets are faced with real wool felt diffraction treatment, the thickness of which is scaled for the frequency range of the driver it is installed around. Cabinets are ported and the volume and Q of each is optimized for tube amps with a lower damping factor. The midranges are mounted in custom constrained layer damping mounts to minimize the activation of cabinet resonances. Bottom woofer cabs are spiked. Response in my room is from around 34Hz to well past 20kHz.

The other critical part of this system is the three way active tube crossover. It is built on three chassis with, IIRC, crossover points around 250 Hz and 2.4 kHz. So the system needs three stereo amps to function. The tweeter and woofer sensitivities are around 95-96dB at 8 ohms and the midrange is around 90db at 4 ohms. So the ideal setup is a minimum of 4 watts on the 8 ohm tweeter, 4 watts on the 8 ohm woofer arrays, and about 16 watts (4 ohm output tap) on the mids. I would call this optimal in an average sized living room. With double that power on each amp you can hit 105dB peaks and raise the dead. I ran them this way in my large listening room at Bottleheadquarters.

I'd like to sell the system in toto someone who would appreciate the effort expended. The system works beautifully but after 11 years it is somewhat shopworn. The cabinets have scuffs and the crossovers are definitely prototypes in appearance under the hood. I would like to get back what I spent on the parts - $3500 (tweeters alone retail for about $1000), which means you get quite a heap of development cost thrown in for free. If needed we can discuss supplying amps to go with the speakers at additional cost. I have a few things available. It is quite a feat to set all of this up in our demo room, and for that reason I would like to set aside a specific day to demo the system for anyone who might be interested. I'm thinking perhaps next Saturday March 16th. email me at docb at bottlehead dot com if you would like to come by that day to audition the system.
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.

Offline Doc B.

  • Administrator
  • Hero Member
  • *****
  • Posts: 7635
    • Bottlehead
Re: My big three way reference system is for sale
« Reply #1 on: March 13, 2019, 04:48:43 am »
SOLD - Thank you so much!
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.