Will this amp trick work for increasing bass performance?

I'm considering matching Focal Utopia Scala Evo with two amps for bi-amping, to separate bass and mid/high. 

I'm considering the Pass Labs XP-32 pre-amp, which has individual volume controls for each channel/amp. By slightly increasing bass amp volume over mid/high amp volume, I get to feel more punch from the 11" woofers. The crossover in the Focals cuts off at 220Hz, so only bass and sub bass are affected.

Which two power amps would you consider? Power amp budget is about $30K. Was told Focals like power, so >250W for bass amp seems the minimum. Pre amp will likely be Pass Labs XP-32.
Maybe Pass Labs X250.8 + X150.8 or X250.8 + XA60.8?

Your thoughts please? Any other ideas to get more bass performance from the 11" woofers in the Focals? Subwoofer is not an option. I know McIntosh has a pre-amp with equalizer, which would solve the problem too. But I always thought EQs are a no-no.
If bass is your goal you will get much better results with a $3k DBA than any amount of money you can throw at any amp the way you're thinking. Period. Full stop. Not even close.  End of story.

Sorry, I can see you have preemptively ruled out the only real solution. Except technically you ruled out "a" sub. Not four. Which is what you need. Oh well. You apparently have no shortage of money. Which is good. The way you're going you will need it. (And still not get there! 😂)
Hi, years ago I listened to old Mezzo Utopias (i.e. not very different to your Focals) driven by two amps vs one and the results were indeed better with two albeit, not overwhelmingly so. We used identical amp models (Soulution).

So, using two amps is a solution -- but an expensive one.
Space and aesthetics allowing, 2 subs may be more effective (& cost-effective).

Mind you, you will feed each amp with the full-range signal from the pre-amp (i.e. left & right). The XP-32 has separate volume controls for EACH channel, right and left--so raising one of those volumes will raise the output of one channel vs the other. I’m not sure how you plan to give more juice to the bass amp?

As to which amps combo: since much of the energy is probably at, or below, 150Hz, the second one seems more appropriate ( X250.8 + XA60.8, 6 dB output difference between the two).Regards
@millercarbon Thanks for your reply. I was not aware a "$3k DBA" could solve my problem. I'm new so please elaborate a little; which one would you recommend? What is a DBA to begin with? I'm very open to other ideas.
@gregm Thanks for your feedback. 2 Subs may be an idea, since with 1 sub in the corner I found the sound too muddy. No coherence, timing off. More bass, yes. But once I switched off my sub, the music fell back into place again. 2 subs would be stereo, symmetrical and may perform better.
30K for bass? Even millercarbon is being is being overly nice.
Good lord...XA60.8 for bass duty... I would never..
That’s a sin not an insult, God can forgive ya, I can’t... LOL
Crown or Parasound maybe, most likely a great class d for 1000.00 or so a pop..
500-2000 watts of pure dark background, cool running amps, that idle at 25 watts..
11" boom, booms will have plenty of headroom, room....AY..

30K Wow.. I’m truly envious. I really am, rare for me. Enjoy...

Tell him MC, spread the word...I’m a column and OB servo guy myself...

DBA is kinda like a Gatling gun, bound to hit something. sooner or later.

BUT it’s better than most...

I was suggesting the X250.8 for bass duties and XA60.8 for mid/high.
But please enlighten me. I'm here to learn something, not to get fried haha.

I'm looking for a way to get more deep bass from my system. What do you suggest?
BTW, saw my first and only UFO in 1976 on July 4. Over 100,000 people saw it in the Bay Area. It was never explained... A true UFO.

Weird... Bicentennial. 5 lights. There is actual footage, GOOD footage..

What a night...Pioneer 6x9s x 4 with a Crag Power play 8 track.
James Brown....Tighten Up....

I was suggesting the X250.8 for bass duties and XA60.8 for mid/high.
No doubt that's what you meant -- hence my comment about the 6dB difference between the two amps (+6 from the bass amp).
As an aside, A'gon member Audiokinesis, a speaker designer, has researched low-frequency reproduction extensively; it may be worth your while to contact him directly -- he is usually very helpful (and never pushes his own products -- which are reputedly excellent, btw!). Regards

The product is wonderful, just a dream come true..

Either or, both are just a Wonderful, a wonderful.. !!!

But bass duty...Really. I suppose it has to look good I suppose it need to match? I duno..

I shouldn’t say things like that.. If you’re looking for the best, you chose it for sure...

I’m still thinking, if I could, would I? Answer is still no..

I couldn’t.. BUT, I’m pretty frugal, 5 or 6 depressions ago maybe.. LOL.

Enjoy whatever it is.. I say great class Ds, will make um hum.

Pass, oh yea..they will sound great... I guess I’m a little grumpy, finishing up my projects..LOL

NO! Buy four JL Fathom subs and place them asymmetrically around the room. Problem solved - and money saved!
Why not get an equalizer?  Much more precise control.  Top level, mastering quality, pro equalizers cost in the $5-8k range.
@onhwy61 Thanks for chiming in. Any suggestions for a good equaliser?

Anybody an idea what @millercarbon meant by a “$3k DBA”. Any links to a product like this?

Thanks @gregm 
I can't send direct messages to @Audiokinesis. Not sure how to reach him on this forum... :(

Dangerous Music Bax would be a good starting point.  The Manley Massive Passive is a more traditional parametric type design.
onhwy614,344 posts06-18-2020 4:52amWhy not get an equalizer? Much more precise control. Top level, mastering quality, pro equalizers cost in the $5-8k range.

Ok we're up to 35-38k, for a little more bass, and control.

A Pro mixer in a stereo system? Is that what you're suggesting?


Everyone keeps saying DBA, He states NO SUBS.

I bet this is a VERY nice room. 

I would use something quietly hidden, with lots of goodies for bass management...300.00 USD tops, daisy chainable, laptop for TOTAL access, parametric and graphic EQ,  threshold limit, timing correction, phase correction, L/R channel summation or MIC data collection/measurments, for real time on the fly remote correction.

Choose good amps. I like class ds doing bass, just makes good $$ sense.. Plug in, have fun...

I've used OXO for bass management 20+ years..
Nothing gets close with my frugal budget..

It's not the Gatling gun, DBA approach.  Much less floor space is being used, or covered in boxes... OPs decor, may not tolerate DBA, not to mention, partners, and or guest..

You don't even have them in your room yet, so you don't even know how they will perform.

I'm surprised getting them setup in their best location first isn't mentioned.
I hope you can get them out in the room, along with appropriate room consderations. THEN, consider all those other suggestions.

I've heard them perform fine with modest tube amps. Add subs...WOW!
I have a superb alternative for you (Frankly, it's showing itself to be potentially a superior solution for all speaker systems). Send message if you wish to have pertinent discussion. :)

1,437 posts
06-18-2020 12:08pm
You don't even have them in your room yet, so you don't even know how they will perform.

I think he has, that's the reason for the biamp, unless I missed something.

He has the speakers, but only a single amp per channel, he want two for more boom boom, in the room room... BUT he wants no subs...

30k budget... 3k aught to do it. He may be picky,and likes Pass, nothing wrong with that.


robert1976 OP
Which two power amps would you consider? Power amp budget is about $30K. Was told Focals like power, so >250W for bass amp seems the minimum. Pre amp will likely be Pass Labs XP-32.
Maybe Pass Labs X250.8 + X150.8 or X250.8 + XA60.8?
I take it Robert you tried kick up the bass a little with the 3 position bass link on the back and you have it on high?
If so and you still don’t have enough bass, you could try to move the speakers closer to the back wall this will augment the bass also.

The Focals have very good passive xover in them especially the Utopia’s

If that’s not enough then what you suggest with "increasing the bass amp a little" will also work and also add more warmth to the lower mids.
Of the ones you suggest I would opt for on the bass X250.8 and the XA60.8 on the mids/highs.
But that’s a bit frivolous to have the X250.8 on the bass to 200hz when a Class-D will do, at a 1/10th of the price.

I’m considering the Pass Labs XP-32 pre-amp, which has individual volume controls for each channel/amp. By slightly increasing bass amp volume over mid/high amp volume, I get to feel more punch from the 11" woofers. The crossover in the Focals cuts off at 220Hz, so only bass and sub bass are affected.
Above will work if you able to control 2x mids and highs and also 2x bass channels with the pre (4 Channels of volume? If not you need this to lower the mid tweeter amp  https://www.schiit.com/products/sys  and then have the XP32 as the master volume.

Cheers George
Too bad you eliminated the easier and best solution: a good subwoofer. İt would have been cheaper too. 
Thanks all, I'm learning a lot! Few points:

1) It's a living room set up, hence my preference to not have multiple subwoofers around;

2) I've tried adding a single sub. Enough bass but too muddy, and for me too difficult to get it right;

3) The 11 inch woofers in the Focal are plenty powerful, but they don't get engaged enough. Simple bass and treble control, like in my car, would do the trick;

4) @oldhvymec I'm not spending an additional $30k+ for bass. That's including an amp I'll need anyway. It's either X350.8 or X250.8 + XA60.8, with the latter costing "only" $4k extra;

5) Not hung up on Pass Labs. Although pricier, I'm also considering Ayre KX-R with VX-R or MX-R;

6) My only source is streaming Tidal (via Roon in future) and I'll probably choose the Ayre QX-5.

To what extent would a high-end equalizer degrade the quality of the signal? Would you notice the extra component in the pathway, even with the EQ set to flat?
I don't mind the extra cost and an EQ will sure do the trick. But if my sound quality is seriously affected, it may not be worth it. Easy enough to try though.

You need to remove the bass from the mid/high amp you can use a pair of Aesthetix Atlas amp it has a internal high pass filters up to 200Hz they start at 10K and go up from there                                                    
biamping can have a slight time issues between the to amps
Few points to consider before spending $30k for amplifiers. Your speaker 3dB frequency cutoffs are 27 Hz - 40 kHz. Specifications says low frequency point is 24 Hz at -6 dB.

Since you are not going to use any sub-woofers, your listening room dimensions must be able to reproduce the low frequency granted you have software that goes that low (e.g., pipe organ music). At sea-level, your room should be at least 23 ft long to correctly reproduce 24 Hz signal. You can get away with 20 ft long room if all you need is down to 27 Hz which I think would be the case. The lowest frequency on a grand piano is 27.5 Hz, which is almost at the start of the human hearing range

Yes, I agree you will need a muscle amp to reproduce bass because it is all about pushing heavy air mass. Sensitivity is 92 dB, but impedance drops to 3.2 Ohms. I would look for a SS amp that can deliver plenty of current. At your price point, there are many choices including Boulder amps for an example.

Good Luck
robert1976 OP

One of these could work wonders for you, they are very transparent and have great adjustablity of ranges. for just $149
And you can send it back after 14 days of trial.

Here’s a graph on what it can do, I have one in my kit and love it when needed, for certain system setups and you just need, one good amp!!!! and a preamp or source with volume and this goes between them.

Cheers George

@pwerahera Thanks for chiming in. It's not a dedicated listening room; it's my living room. It's 30ft wide and 28ft deep, with openings to the left and back. The X and * mark speakers and listening position:

             |      *       *       |
---------           x           | 28ft
|                                    |
---------           ----------
             |          |            
             |          |  

@georgehifi Thanks for the suggestion! If it's very transparent, it can't hurt to try it out. Currently I use XLR from pre to power amp.
Using this tone controller means I have to go RCA all the way right?

Would changing from XLR to RCA make any difference?
robert1976 OP
Using this tone controller means I have to go RCA all the way right?
Yes you will have to do that.

Would changing from XLR to RCA make any difference?
Only benefit for xlr if the interconnects are very long >10mts xlr then helps for noise if any.
And in some cases rca sounds better, as the xlr input and outputs on many bits of equipment are fake! Using balanced opamps with what is single ended circuitry throughout, so the rca input or output in these cases bypasses those balanced opamps and goes straight to the single ended circuitry input or output.

Cheers George

You do not need to bi-amp, but you will need a powerful, high current amp.  To best implement an equalizer you will need a preamp with a tape loop.  Most tape loops are single ended RCAs, but there are some preamps with balanced tape loops.  The other alternative is to insert the equalizer between the preamp and the power amp.  The most tone control like high quality equalizer is the Dangerous Music Bax.

Does anyone know if Tidal has built-in EQ functionality?
I have to agree with millercarbon on this one, that is that a DBA would be the way to go.

That's a really large room for two 11" woofers!

I see that the rear of the speakers has speakers terminals labeled "Bass Input". Does that mean you can bypass the internal cross-over?  IF so, then you can, go here:
https://www.marchandelec.com/xm44-electronic-crossover.html  and purchase an external crossover (2 way any slopes you like and control the gain as well)  requires a second amp of course.  

The cross-over will run you about $1500-$1700, depending on options, like fully balanced, tubes etc.

Then borrow an amp and give it a try, seems to be a cheap experiment given the $$$$ you are willing to spend.
Thanks @onhwy61 , I just found this https://apps.apple.com/us/app/boom-bass-booster-equalizer/id1065511007

I'm out of town, so I can't test this at the moment. Looks promising since Tidal is my only source!
You are certainly on the right track.  By using separate amps with separate volume controls, you can increase of decrease the bass without destroying the linearity of phase aligned speakers, and without changing the linearity of the bass output with a tone control.  I am a definitely a Nelson Pass fan, and had forgotten about his pre-amps with dual volume controls, so I use a pair of Audire Diffet 3's.  It really works!   From my comments, you would be right to surmise that I would never go with an EQ.
I have to chime in here. Paul McCowen from PS Audio said the best way to connect your subs was to connect them directly from the speakers to the high level inputs on the sub. (he has a video on the topic) In this way it picks up the dynamic characteristic of the amp. Connecting straight from the pre-amp is passive.

The result of this change was nothing short of amazing. For so many years I had my subs connected 'passively' to pre-amp. This change has added dynamic 'punch' and tightness like I've never had before. I now pick up the punchy personality of the amplifier. Not more bass but tighter bass. Exactly what I had been searching for over many years. Bass you can feel. Provided your sub can accept high level input connection this is a game changer. It's a simple, cheap connection taking a few minutes to change and the results are huge!!

I have two 12" inch subs in stereo connected directly to my McCormack amp and my search for better bass has ended thanks to Pauls simple trick. Makes me wonder why the entire industry suggests connecting to the pre-amp. 

Tidal question... from what device are you streaming from? How is the connection made?

@gdaddy1 Did you say "connect them [subwoofers] directly from the speakers". Can you elaborate on the exact wiring in this scenario?

I play Tidal via Chromecast to my streamer, wirelessly. I also have a AudioQuest Dragon Cobalt that I attach to my iPhone or MacBook, then via a 3.5mm to RCA to the pre-amp.

I got suggested that Roon can play the Tidal library too, which superior results

I just positioned Two xa60.8's in my listening room. They are paired with Paradigm Personal 7F's and a Premaluna Preamp (EVO 400), streaming Qobuz on Lumin. I am literally 30 hours into burn in. Our specs are not exact, but similar. You're getting a lot of great advice from some qualified folks. To fill my knowledge  gaps, l called Pass and spoke to Kent ( long term technical support), he was excellent to work with. I was looking at all the same amps and he astutely guided me to the 60's. I purchased the from Reno HiFi. Mark is the owner and excellent to work with. I wont speak for him, or the options he will positioned, but I was very confident he would work with me until I had the amp/s I wanted. The bass generated is significant tight and very detailed. I have two subs from the previous configuration that are unlikely participants in the new line up. This is not an advertisement for either, my first exposure to both, just an excellent experience I want to advocate.
@mkdm11 Thanks for sharing, are you bi-amping the XA60.8? Please elaborate on how/to what you connected each power amp
Yes, provided you have 'high level input' connection on your subs. Most higher quality subs have two ways you can connect. Either 'low level' RCA connection from your pre-amp (passive) OR you can run a short set of wire directly from the back of your speaker connection to the 'high level' input on the sub woofer. 

Super easy to do provided you have 'high level' inputs.

The reason I ask about Tidal is that some people connect from the TV app. This method gives you low resolution and very reduced dynamics.
Your connection seems to be fine.

Don't know the best way to connect an equalizer to the Ayre.  Address the question to the manufacturer.
I am not bi-amping.
I am going from the amps to my speakers via a high-wire configuration, dual wiring on the speaker side.
If you are concerned about having enough power, remember xa60.8's are class A to 60w then convert. Class A is much more efficent. My strategy in Class A and Tube Pre was to drive the purest most musical combination I could design. Maybe consider bi-amping as a second option if you feel your speakers are not being driven. In my case, I don't  believe it will be necessary. 
Again Kent at Pass was an excellent resource. I believe I spoke to him three times before making my purchase. The EVO's are sensitive, any of the Pass amps you are considering should drive them.
I also have a large room, and my solution was to triamp with an SS amplifier for the 2 subs (LP @ 48hz 24db/oct) Magneplanar MG 20 bass panels on another SS amp (LP @ 220 Hz 6db/oct, no HP filter), and a third amp (Tube) serving the Midrange/tweeters (HP @ 290 Hz 6db/oct, no LP filter). The crossovers are Pass Labs XVR1s. This stereo is way out there for a system, but it really sings! I have made incremental changes, one at a time! to arrive at its present incarnation.
You really need to experiment with the speaker locations to get the best compromise between imaging and bass response. I am pretty sure you will need to have a stereo pair of subs to get the bass right for audio and audio imaging. Two subs will allow more flexibility in the room setup, and some of them are pretty small, which will help the "cosmetics" of the room. (WAF). I have read good things about JL Audio and SVS for subs. JL Audio has a couple of in wall subs that can be completely unobtrusive.
Good luck, this sounds like a really cool project!

Just to be clear, there are two versions of bi-amping, vertical and horizontal.

Horizontal, you use one amp on the bass inputs of both speakers, and one on the upper frequencies. In this arrangement, if certain requirements are met, you can use a more powerful amp on the lower.

Vertical bi-amping uses two identical amps, using the L and R channels of one amp to power the upper and lower inputs of one speaker.

I presume that this is what mkdm11 is doing.

Vertical biamping ( can only be successfully done with identical amplification, as mentioned above ), has always been better, in sq, to my ears.
This is a nice problem to have. Get the XA60.8 on top and a pair of JC1+ amps on the bottom. If they are anything like the old JC1 they will have a damping factor in the thousands and plenty of power Fabulous bass. Better than any Pass amp I have heard and Pass amps are no slouch. The XA60.8 will be like heaven on top. When you get it done please invite me over. 
FYI... Paul McGowen just posted another video explanation of the importance of the subwoofer and the importance of the connection to the 'high level input' of a quality sub. 

I believe you are on the right track. You probably don't need a sub unless you are listening to EDM or at concert level volume. Focal recommends an amp up to 500 watts, so depending on how much bass you are looking for I would get an amp as close to 500 watts as I could afford. You have a large room which makes it easier to over drive an amp powering the low end if you going for high volume.

Adding eq can help tailor the sound even more if desired. If you are looking for that chest thump you could further accent the 40 to 80 hz region with out boosting the 160 to 220 hz area which can start to give you that hollow, in a tunnel type sound, depending how surgical your eq is.

I believe that Pass amps and pre amps are truly balanced so if you convert the balanced output to RCA I believe you will loose 6db of out put
Thanks @audiorusty, will keep that in mind. 
Just auditioned a McIntosh pre amp with built-in EQ. That solves my problem in one go.
Someone said an EQ downgrades the quality of the music. “So does a room”, was the sales advisors reply. “It’s a very small trade off, but think of the EQ as a room correction tool”. My system will be in the living room, so I’m very limited in terms of room treatment. 
Also looking at Wilson Audio Sasha and Alexia Series 2 now. They only spec the minimum power, not maximum.
The Alexia’s had muddy, boomy bass despite the room being properly set up. The sales rep assured me it’s because the 350 sq ft room is too small. And this won’t happen in my 860 sq ft living room, with large openings to the kitchen and study.