ProAc Studio 140 too bright (?)

Yeah, maybe. But there is a hope: Shivermetimber's gear is almost identical to mine and he is not complaining about brightness of the speakers.

 

IMHO it is very unlikely that I have faulty crossovers in both speakers?

 

Insert an L pad attenuator on the tweeters .
Also try some solid core copper speaker cable.Lighting cable works well and is cheap.

 

I wouldn't go for the L pad attenuator. I think that a speaker manufacturer (especially ProAc) has enough know-how and experience how to design a crossover network. They know what to do any why.
I am using solid core 2,5 square mm fire resistant cable. This helped a bit bot only a bit.

 

Jenkovix,

Some people wire ONE tweeter out of phase and claim improvement.

 

I'll give it a go thanks for the input!

 

Not a great experience then!, and diametrically opposite mine. Odd. If anything the sound was a touch bottom-heavy (well, slight looseness to the bass) for my taste/room and I addressed that with new input valves... but anyway this thread seems to be more of a speaker issue.

 

I'll be the third to add some more comments and opinions here.
Please be patient tomorrow I'll start experimenting with the hints I got on this forum!
Cheers!

 

Dunno...I haven't heard these particular speakers but silk dome tweeters tend not to be overly bright or forward. I'd look at placement and room treatment. The enclosed review suggests they are more demanding than most in this regard.

 

Then do what another poster recommended, treat your room.

My room at home has a nice wool rug, long drapes on every window and slider...etc. A pair of speakers I own sound great there, warm and smooth.

I tried them at my beach place, no rug, no drapes...etc. The top end is ear piercing but the mids and bass are great. I did as much treatment as I could to the room with what I had, made a huge difference smoothing out how harsh they sounded.

Now I know what I need to do to that room.

 

Hi all,

finally I am back from the weekend. During the two days I did everything possible and impossible:
-positioning speakers
-bi-wiring and single wiring
-changing interconnect cables
-more room treatment
-rolling between stock tubes and custom tubes (Gold Lion KT88)
-adjusting PrimaLuma's Autobias board
-different materials under the speakers
-4 ohm taps (this killed the excitement of the music, everything became dull and lightweight)

All I can tell you that none of them worked unfortunately. It is not the room, not the sources, not the cables. I have only a little more gunpowder and this is EL34 tubes. I'll get a set of four and try them instead of the KT88s. But other than that I have absolutely no more idea.
I hooked up the JPW ML-810s and they also became aggressive in the treble. Not as bad as the ProAc but still not pleasant.
My final conclusion is: I have two wonderful hifi components the PrimaLuna and the ProAc. Both of them can be forward sounding (reviews on the web confirm this) and in my case the two adds together and amplifies this effect and this leads to that ear-piercing phenomena. Why this combo is good for Shivermetimbers I dunno. But he is a very lucky guy I have to admit.
And now what? Sell the amp? Sell the speakers? Or sell both? Than I would have to start from scratch only with sources.
Not an easy hobby...

 

So using the 4 ohm taps cured the brightness!!!.......LOL

Sorry .....just a joke........it is a real shame that you tried so hard to solve the problem to no effect.

Based on the part of your post I bolded.........it's looking like the PrimaLuna is more the culprit.

Maybe it's time to audition some "warmer" amps.

If the sound is still bright after that then I guess the tweeters in the ProAcs are just too "hot" for your system.

No reason to get rid of BOTH though...........you simply need to find the right partner for whatever you decide to keep.

If it was me though I would probably just try other speakers........they will always have more influence on SQ than an amp anyway!!


Good Luck

P.S. Did you try wiring one tweeter out of phase?

 

I ran a Prologue Two for a fair while and really liked it. The stock tubes are not good IMO, very easy to better. I much preferred it running EL34s than KT88s; a warmer, friendlier and more liquid sound, I mainly used Svetlana Winged C and for a while a lovely (borrowed) set of NOS brown base Teslas. The 12AX7s and 12AU7s are critically important to this amp's sound. After much fiddling I ended up with a pair of Sovtek 12AX7LPS and some NOS black-plate RCA5814As in the AU7 positions. With this tube set it was a seriously good amp IMHO. I ran it with many speakers including for a short while some ProAc Tablette Ref 8s and it sounded great, not hard or forward at all. If you really want to warm/soften it up try some mid-60s Mullard ECC83 and or ECC82s, though they tipped it a bit too far in that direction for me.

 

What's your background, in terms of your audio Journey; what have you owned, liked, traded, etc? Both previously and in this room? And what is the room like?

 

While it would be disappointing if alternative tubes don't do the trick, I agree with Tony L's recommendations. Good EL34s would be smoother and warmer than KT88s, particularly since most amps come with cheaper tubes that can be bettered with alternatives. If your amp can run them, 6L6s would also be a move in the right direction.

 

I changed some input tubes, those being Tung Sols for Mullards for a different amp. Although it was not a Prima Luna, it was WAY too up front after switching the Output tubes to a more powerful set.

Changing the input tubes solved that problem, but as Tony mentioned, it removed a bit of the intensity that I sort of liked. But, given the two, I'd go for a more mellow, less intrusive presentation.

 

Ah what a bugger; sorry none of that worked out. Fingers crossed the EL34s give you what you want - let us know what you find.

Any hifi stores you could take the PL2 to compare against other amps? And how long have you had it?

 

I not only changed the KT88s but the 12AX7s and also the 12AU7s. I have Black Sabre 12AX7 LPS:
https://tubedepot.com/products/black-sable-sovtek-12ax7lps

and NOS RCA 12AU7s (also from Tubedepot). Though with these it is very harsh too and with stock PL tubes too.

 

I have the amp for 5 years now. Plenty hifi stores around.

 

I used the Black Sable cryod Sovtek 12AX7LPS myself and loved them, I actually found nothing I preferred to them despite trying a fair bit of fairly expensive NOS. Which RCA 12AU7s did you use? I like the '70s grey plates with the top getter, though the black-plate 5814As were definitely better (just more solid and powerful sounding). I was not a huge fan of RCA clear-tops, I found those rather bright and thin. Beyond that and recommending you try a nice set of EL34s (I'm pretty convinced the Prologue Two's output transformers are optimised for 34s despite it being able to use other things). Is there anything odd upstream of it? It is a revealing little amp, as are ProAcs, so if something is wrong with the turntable setup or you have a lot of badly mastered CDs it will certainly let you know! I'd expect it to sound crisp, open and dynamic with a real walk-around soundstage. It should be a really nice system!

 

Yes, tube rolling reloaded what I am planning to. This includes EL34s and something else instead of the NOS RCA 12AX7. Maybe some JJ will see.

 

It might be a pain but I'd be tempted to take the amp along to a store and compare it to some others, or get one to demo at home; especially if the EL34s don't work out. Get another frame of reference.

Again I've only changed the input valves (Sovtek 12AX7 LPS and RCA black plate 12AU7) only, and they did alter the sound notably, and nicely, but not the fundamental performance/nature of the amp. Perhaps the power tubes will have a greater influence.... (I'll look to try some in the near future).

 

I called a local hifi dealer today and told him my pain. He has not a good opinion on the ProAc speakers... I'll bring the amp and try a few setups there. Stay tuned...

 

Somebody else with a similar problem :
http://www.whathifi.com/forum/hi-fi/bright-harsh-sound-my-proac-d18

Also the 140 mentioned here. No tweaks worked for him either. Look, my previous thought (bright amp and bright speaker together) seems to be confirmed here:

"Proac does midrange superbly well but it is still a hefty price to pay, IMO, if the amplifier needs to be specifically matched to run these speakers to tone down the harshness."

Complaints about harsh ProAc can be found also:
http://www.whathifi.com/forum/hi-fi/driving-proac-d38s

"The problem is the top end sounds harsh, in fact some tracks are difficult to listen to they are so harsh, which is very disappointing."

It looks like a common problem with ProAcs. Some people are lucky with they amp some people are not. I belong to the second group...

 

Digging up the net at the moment, same topic here:
http://www.audioasylum.com/forums/amp/messages/8/81804.html