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Next thing to improve......

As some of you are aware, my diy system has been slowly evolving over the last decade. It is now a 3 way system – Eraudio ESL3 panels (reconfig’d) each mounted above a pair of Peerless 8” drivers. 2 subs, one in Lrear corner , one midway along R wall. MiniDSP is used for the woofers and sub woofers, not the panels. Xover frequencies: The panels are not filtered but have a measured roll-off from about 600Hz at 6dB/oct. The 8” woofers do not have a HP filter at the bottom, but the LP is set currently to 400Hz with a 12dB slope. A steeper slope would have been nice but the miniDSP distorted when I used a higher order (detected recently and luckily, listening without the panels). Subs have a LP around 50Hz IIRC. All in all it is sounding pretty damn good, finally, but wait, there’s more, or at last I think there is more to be gotten out of the system. The front end is cheap, a $60 dvd player going into a passive preamp. After delivering a thin, but clean sound for years, Trevor Wilson (Zaphod Beeblebrox on SNA) convinced me that the impedance characteristics of the passive pre leave a lot to be desired, even if they do deliver a clean treble. So I added a buffer stage (AD825 based with 20% lift in gain) and sure enough improved low-mids and bass and that is where my system is currently. (Oh amps are ME550-II for the panels and a Luxman integrated for the woofers, subs have 200W Oaudio plates in each). Nagging away at me is the reminder that I borrowed some ME preamps off Trevor a long time ago, before I added the buffer, and they were good. At that time I had not addressed bass, nice extended deep bass, which I have now. So I have spoken to Trevor and he is going to let me trial a reconditioned ME24 once more, maybe 7 yrs later. I have no idea if my passive + buffer is any good or not, but will soon find out !! I am hoping that even better current drive will provide more bass from the panels, ie lower the rolloff point, but also sweeten up the high treble. ESLs also have high impedance up above 10kHz, so better current delivery might help up top as well. I'll let you know in a few weeks. Hey, I didn't say it was going to be interesting........

Comments

  • They invented paragraph breaks for a reason....

  • OK I made it through. How is a different preamp going to give you "better current drive will provide more bass from the panels "?

  • Ok, well we enter a world where I believe certain "facts" without truly understanding them ie I could be wrong - "a little knowledge is a dangerous thing". Paragraph break. Anyway here goes ...(no paragraph break) .. I believe that one of the results of suboptimal impedance matching is current supply for all, varying demands. This impacts bass typically. (I'm sure there is more to what I have just claimed). Paragraph break. Now for the panels, I am pretty sure the panels rolloff is from dipole cancellation, but I'm hoping it is also due to impedance issues. Which reminds me, I was wrong in the above paragraphless missive. The buffer I inserted, is not after the passive preamp, it is after the passive output stage of my Rakk dac. Trevor is not a fan of passive stages and suggested that I really needed 2 buffers and I did half the job. I put 1 in the dac and bingo he was right, much fuller sound. So the ME preamp is almost certain to deliver further improvement, comparing to a passive tvc preamp, even if it doesn't lower the panels' roll-off. BTW, the impedance output of the Rakk dac passive output was way high. 3kohms ??

  • edited April 2015

    But, the preamp isn't connected to the panels. Paragraph break.

  • yes it is.... it has 2 outputs (and I don't mean L&R). 1 set goes to the ME550 and the other goes to the {paragraph break} miniDSP which controls the woofers and subs.

  • The shin bone is connected to the hip bone :-/

    Anyway, when are you getting it? Did you know that "Trev" is short for "Trevor" and if you spell it backwards you get "vert" which is short for "vertical"?

  • Here's a diagram M O Q it's a cat- but spaces have been inserted - damned paragraph breaks.

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