ProAc sound with SS vs tubes


I am close to buying a Proac D20R. I listened to them at the dealership yesterday, driven by a low power PrimaLuna tube amp, and was totally gobsmacked by the glorious midrange. When I get them, I will be driving them with something very similar - an EL34 powered 40w/ch tube amp. So I have a feeling they will perform close to how they sounded at the dealership!

The one caveat was that at the demo, when I played a bass-heavy electronic track and pulled the volume up, the bass started to get flabby and the port started "huffing". I don’t know if that is the technical term, but it felt like the speaker was losing grip on the bass and starting to lose control of the lowest frequencies with the synthesized bass jabs losing their timing. The track was Algae & Fungi, Part I - by Biosphere from the album Cirque, in case anyone is interested.

Based on that, my question is: is this something that is inherent to the speaker? I plan to switch my tube amp to a SS of significantly higher wattage soon. I am thinking either Ayre-V5xe, or the Hegel H-20 or one maybe even a Plinius-SA102 or SA-103 if I can find one at a reasonable price.

Can any Proac owners tell me if the bass response will tighten up with more power and a SS amp behind the speakers? Or is this a limitation of the D20R’s design that it’s bass response will not be well controlled with tracks that are bass heavy and highly rhythmic?

Thank you so much!

The one caveat was that at the demo, when I played a bass-heavy electronic track and pulled the volume up, the bass started to get flabby and the port started "huffing". I don’t know if that is the technical term, but it felt like the speaker was losing grip on the bass and starting to lose control of the lowest frequencies with the synthesized bass jabs losing their timing. The track was Algae & Fungi, Part I - by Biosphere from the album Cirque, in case anyone is interested.

And when you pointed that out to the salesperson he/she said what?

Was it the fault of the speakers or was it the fault of the amp?

Did you try the speakers connected to another amp? Same results?

Will the dealer let you take the demo speakers home on the weekend just before he closes for the day and bring them back on the morning of the day he reopens, so you can hear them in your room connected to your system? Many dealers will write it up as sale with a note on the receipt saying full refund on return if returned by (date) in the same condition the speakers left his store.

@jea48 The dealer did say that it was most likely the amp running out of current. Which makes sense - since I have not heard too many people complain about ProAcs being bass shy.

That said - I would love to hear from other D20R owners or people who have tested it - if they have encountered anything that concerns them about the low-end control on these speakers.
Hi Badri,

I auditioned the D-20R’s with my Manley Snappers. We ran them
in Ultra Linear (100W) and Triode (~30W). I actually preferred them
in Triode mode. The sound was more open and balanced in my opinion.
I ultimately ended up with the D-30R because it was about as big a speaker I could comfortably fit in my room. I run them in Triode mode
and still have dynamics to spare. A few things to note about Proac’s,
is that they do need time to break in. They can sound a bit tight and I recall the bass being a bit loose. At about 50 hours I started to hear noticeable improvements.
They also need space to do there thing. Too close too the wall and bass can be over powering and sloppy. The D-20R put on a good show and I was impressed with what they can do, especially at the price.
There are a few things at play here. Proacs like tubes. I believe a solid state amplifier would tighten up the bass, but you might lose some of the magic in the mids, and overall, get a less "relaxed" sound. A more powerful tube amp (50~60 watts/ch or higher) will most likely solve the issue of the amp running out of current that you experienced at the dealer. Also something else to consider - the amp at the dealer - did it have more than one set of output taps and which was being used? Assuming the amp had more than one set of output taps, switching to the lower value may provide more control in the bass. Lastly, my guess is that the D-20's strong suit is not bass-heavy electronic music, and you may have been pushing the speakers to their limit. Also, need to consider any differences in the room at the dealer vs. your listening room.
Proac's like tubes. Good quality tubes. EL-34 tube amps are not well suited to bass heavy electronica. QuickSilver Mono88's or Mono 120's (running KT-150's) are a fantastic match with Proac and would suit your music preferences. Bass control will not be an issue and you'll get a quality & beauty of midrange that 95% of SS amps will not attain. The comment above about run in time is also spot on. Proac's need a lot of running in to show their true colours.
@cmach Thank you for letting me know about your experience. I have gone ahead with a second-hand purchase of a D20R as opposed to buying it new. I managed to get a Mahogany pair that was listed on here, infact! I was worried that the D30R might have been a little too big for my room - though I really wanted them badly - seeing as how their drivers were made of a very different material and might have behaved more gracefully under pressure.

@nicotico @rothwea That’s interesting. I believe the Jolida’s are known for being easy to roll new tubes into. I might call the local repair shop and ask if the circuits internally can power a higher power tube like the 88s or 150s - and if the output transformers are capable of higher current delivery. If they can, I might just get that done.

In the meantime however, I have managed to get a second-hand Plinius Hautonga integrated. I hope that manages to control the bass more effectively. I will have about 1.5’ behind the speakers and more than 3’ from side walls for each of them (leaving about 6’ between them). Hopefully, this is enough space for them to project a good soundstage, image well and also have a controlled bass.

The midrange is what drew me to these speakers. I don’t think I have visibly melted more into the music than when I listened to these. It was the most generous and enveloping kindness of music I had heard in a while. I hope to retain that quality with the Plinius and hope that the magic stays.
I recently demoed some ProAc D18s and some used ProAc Studio 125s.  Both are lovely speakers but I heard a similar problem to the huffing / bottom end getting loose with both choices mentioned above.  I decided to go out on a limb and have my ProAc dealer order me some Studio 148s.  Very efficient speaker that fills the room and goes very deep with great control.  No huffing or bottom end getting loose.  Plus is a down firing port and did not take up any more room than my Tekton 6.5t monitors on rigid stands.  I am driving them with Audio Refinement separates (a step up from the well praised Audio Refinement integrated amp).  The rest of the details are on my system page.  So glad I took a chance with the ProAc Studio 148s.  I use them with some Soundocity SEV9 outriggers with some spike floor protectors on hockey pucks, all sitting on my carpeted floor.
@sbrownnw Thank you for sharing your experience. It is certainly bittersweet to hear that!

I am so glad you ended up finding that the Studio 148 worked for you. The D20R has a downward firing port as well - but there was just not the degree of control I would have expected. I am worried that the 20R is going to behave badly in my room - and I will potentially have to move up to the 30R or the 148s such as yourself. Or perhaps - look at the ATC line a lot more seriously seeing as ProAc sometimes use ATC drivers - especially for the midrange - but the ATC are a sealed design known for being "rock music friendly" - whatever the hell that might mean. :) 

I really really really hope the 20R behave better with the power of the Plinius behind them.

*fingers crossed*
@badri, I think you will really like the Studio 148s. Strings, violin through double bass have great tonality and presence. Plus I was listening to a CBS Talking Heads demo LP and The Crystal Method’s latest LP last night and both just rocked going quite low with great control and lot of air being moved.
@sbrownnw I was hoping you wouldn't say that - hahahahaha :) I was rather hoping to live with the 20R for a while instead of switching immediately. :)

But- thanks for letting me know that the 148 did work with more bass heavy stuff.

I think at the end of the day, it is going to be hard to get something working in a 13x13 room, without a sub, that has a full & beautiful midrange, is extended in treble but not overly bright, has a tight, deep and well-controlled bass response but does not have bass boom, is fast and fits within a reasonable budget. I know I am asking for a lot. :)
I also home demoed a pair of Ascend Sierra Towers with the RAAL ribbons.  Didn't like them even though a lot of people seem to rave about them.  Did not have the punch, liveliness and lower end that the ProAc Studio 148s have.  I think there is something said about lively equipment stands, speakers like ProAcs and turntables like Regas.  Overly reinforced speaker cabinets plus the enclosed midrange driver like the Sierra Towers in bamboo sounded like they had no energy, PRAT / punch or bass.
@badri .......I think you're going to be pleasantly surprised/relieved with the ProAc d20r in your room.  As the saying goes, "you can't have it all".  This particularly goes for speakers.  Just the midrange and ribbon tweeter alone is worth the price of admission to the Proacs.  They've got the best mids I've ever heard.  That's saying a lot.  The bass player s not bad either.  If your music requires that much base and fullness, better start thinking a sub.  Keep me posted and enjoy.

@carmenc I know what you mean about the midrange. That is what got me. I fell for it hook, line and sinker. Sat in my chair mouth open, gaping. I don't think I had heard something more elegant and lush. I know that at least for a good chunk of what I listen to (baroque, vocal/choral music, chamber music, modern/contemporary classical) it will be fantastic. For the other bit which is contemporary electronic such as Autechre, Plaid, Aphex Twin, Boards of Canada, Luke Vibert etc - I have a feeling I am gonna miss some things. But as you said - you can't have it all :) Just hope I don't have a bad case of buyer's remorse! :D
I own Proac D 40r speakers which are bottom ported. I have found them to be flexible with regard to placement and no issues with chuffing. I used them for years with Quicksilver V-4 amplifiers and recently changed to an Aesthetix Atlas (all Aesthetix electronics now) which is also a very good match with the Proactive speakers.
@jperry That confirms what I have been hearing around here and elsewhere. The higher end models in the Response range such as the D30R, the D40R and the brand new D48R all seem to get rave reviews. The 20R alone seems to suffer from bass control issues and is considered by some to be worse than the D18 which it is supposedly based on.

This is why I was wondering if the issue was a case of overall system match and if the 20R bass sounded better controlled with high power solid state electronics.
The bass control is better with the Aesthetix Atlas, but they sound great with tubes. It really depends on the type of music you select. For small jazz, female vocals, folk music, etc the Quicksilver amps are tough to beat.
Looking to purchase a pair of D48R after shortly after Axpona. I would like to keep it simple and go integrated. I listen to mostlyJazz and classic Rock. My room is 23 x 15. I would appreciate any suggestions.
@badri, I would recommend the following setup, which I am using with my Studio 148s, to possibly help tighten up the bass you are concerned about:

Soundocity SEV9 outriggers:
I like them as they are easy to level the speakers as the spikes adjust from the top.  Use them under the supplied ProAc plinth and do not use the supplied ProAc spikes.

Some speaker spike floor protectors like the discs shown here (unfortunate they do not sell just the protectors separately:

8 hockey pucks from a sporting goods store (I got mine from Sports Authority).

The hockey pucks rest on my carpet with the metal speaker spike protectors on top of the hockey pucks and then the Soundocity SEV9 rest on the floor protectors.  Easy to level and I really think this setup lets the downward firing port breathe and have the right distance between the floor and the port flare.
Stopped using the hockey pucks and, instead, using metal spike floor protectors (even though my listening room is carpeted) under the Soundocity outrigger spikes.
I know I'm a little late to this thread, but I wanted to throw in my 2 cents worth.  I owned the D20r's and experienced the same issue with the bass using both tube and ss amps.  The midrange and imaging are amazing, but I was able to move up to the D30r's in the last couple months and it's in another league sonically than the 20's.  It's a more refined speaker all around and absolutely no issues with the bass.  Very tight, deep and clean.  It's definitely a big step up in my opinion and doesn't lose any of the midrange or imaging Magic Proacs are known for.