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June 18, 2019, 08:07:52 am

Author Topic: Setup with S.E.X. 3.0 - will this work?  (Read 207 times)

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Offline Zerileous

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Setup with S.E.X. 3.0 - will this work?
« on: May 21, 2019, 12:01:14 pm »
Hopefully this is the correct sub, the S.E.X. subforum seemed to be very much geared toward technical aspects of builds.

I have a pair of Pure Acoustics Dreambox bookshelf speakers. 8ohm, 90dB, 80W RMS, 3" drivers. I bought them with the TubeCube7 from TubeDepot, but I no longer have that amp. Will these work well with the S.E.X. in a 17' x 25' room, or will there not be enough power? With the TubeCube7, it was rated at 3.5WPC but it would start distorting at about 60%. It doesn't have to be super loud, but am I right to think these will be under powered?  I also plan to use a pair of Sennheiser Massdrop HD58X Jubilee headphones.

Source will initially be an U-Turn Orbit TT with the Ortofon OM5-Eand possibly a TV or Chromecast Audio at times. TT will be using either the Rolls or or the U-Turn phono stage.

Does the S.E.X. require a pre-amp as well, or is it an "integrated" amp? I also plan to use a pair of Sennheiser Massdrop HD58X Jubilee headphone

I'm pretty new right now, however my interest has been sparked by pairing the Sennheiser cans with my PC's onboard audio (yes I know, but it is actually quite good, at least compared to your average smartphone or PC).

I'm also considering the Musical Paradise MP-301 as it has plenty of power for those speakers, or going solid state with a Rotel RA-12 or A-12 (mainly for it's DAC and versatility in inputs). I think the Bottlehead kit would be a fun experience to assemble, but I'm worried that it won't be a great match for my existing equipment, or the size of my room.
Justin Nichols

Offline Paul Birkeland

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Re: Setup with S.E.X. 3.0 - will this work?
« Reply #1 on: May 21, 2019, 12:36:37 pm »
This is a substantially more complicated question to answer than it would appear.

The more pertinent question is whether the Deambox speakers would work for you on any amplifier in a room that large.  My experience with 3" drivers is that many of them will only handle a little tickle of power at low frequencies.  This gets exponentially worse when you have a ported enclosure that's tuned fairly high, and this is very typical for a speaker with a 3" driver.  So in this regard, you could have a 500WPC amp on these speakers in your room, and you may have the exact same problems that you would have with a SEX amp.  I also have some extreme skepticism regarding the 90dB sensitivity rating just based on nearly every other 3" driver being around 85-87dB sensitive or much lower.

If we look at a really nice carbon fiber 3" driver like this one from SB Acoustics https://www.madisoundspeakerstore.com/approx-3-fullrange/sb-acoustics-sb10pgc21-4-3-full-range/, its efficiency is 81dB/1W/1M and it will handle 1W at 55Hz before driver performance suffers terribly and perhaps a little more before the voice coil former runs into the back plate (this makes a loud popping sound that has nothing to do with the amplifier)

The SEX is indeed an integrated amp and won't require a preamp.  It will be a stellar match for your HD58X headphones (as would the Crack), and you may simply want to consider a slightly larger speaker that could better fill your room on less power.  There are many available used from 20+ years ago that have an 8" woofer and a silk dome tweeter that will play pretty loudly on 2W.  If you post your approximate locations, there may be some good candidates floating around on your local Craigslist.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Zerileous

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Re: Setup with S.E.X. 3.0 - will this work?
« Reply #2 on: May 21, 2019, 04:37:02 pm »
Thank you Paul. So I re-measured the room and it turns out that my memory is not great. The room is 14'x13'. They do get plenty loud with an Orb Class T amp at 20 WPC, however the amp is really unsatisfying for me.

That said, I understand if the speakers are simply not a great fit for my needs and would be willing to consider replacing them.
There is not a lot on the Craigslist in South Dakota, however I will be in the Kansas City area next week which could be more fruitful.

I started with a $500 budget for amp + TT, however I am willing to break the budget in order to get the sound I desire. I guess my more realistic budget all up would be around $1000. I want something similar to what I experience with the HD58X in terms of clarity and staging. I would also like some of the liquid tube sounds that were so captivating with the TubeCube7.
Justin Nichols

Offline Paul Birkeland

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Re: Setup with S.E.X. 3.0 - will this work?
« Reply #3 on: May 22, 2019, 03:49:17 am »
Ah, yes, I've recently made a few friends from Redfield.  Even Kansas City looks to have ridiculously high pricing for used speakers for some reason.  Knowing that you can stretch your budget if you need to, it puts a bit less pressure on the SEX amp if you end up needing to find a slightly more sensitive speaker.   
« Last Edit: May 22, 2019, 09:08:27 am by Paul Birkeland »
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Zerileous

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Re: Setup with S.E.X. 3.0 - will this work?
« Reply #4 on: May 22, 2019, 06:41:18 am »
To be honest I'm not surprised. I just read a thrillist article that referred to my hometown as, "the next Austin." I have certainly noticed the growing hipster presence, and I appreciate many aspects of that, however I can absolutely see that driving up the cost.of vintage hi-fi equipment.
Justin Nichols