Need help What monoblock power amps for bass?

I own a pair of Silverline Sinfonia speakers.These are very large speakers (over 240 lbs. each),96 dB and 8 ohm stable.Very aesy load for any amp,so power is not mandatory,anything over 50W/ch is OK..
They are tri-ampable.I am looking for opinions on what monoblock amps to use for bass drivers ONLY.Each Sinfonia has two 12" woofers and one 7" woofer.7" driver also contributes to midrange,so this is the trickiest part of my amplification story.I don't want mellow and soft bass,but don't want cold vocals either.
I plan to use either tube or SS monos and limit them whit a potentiometer in order to achieve a tonal balance with midrange and tweeter.Midrange and tweeter will be powered with 320B XLS SET monos (30W/ch).
The areas i am looking for in bass are - slam,speed,definition and ambience.I like fast and tight bass (often connected with SS amps),that is a priority.
Any suggestions will be very welcomed.
I would think twice about using two different amps to do the job. You are opening a whole new can of worms with matching output as well as in other critical areas.
Bryston 7BSSt maybe, but if it were up to me I would 6 times the same mono blocks. Maybe you can limit them with a potentiometer but what about input impedance?
Bryston 7BSST mono amp would work awesome. Plus, 20 year warranty.
Check out Wyred4Sound SX1000s. I am using SX500s on my mggie mid/bass panels. They ae outstanding and energy efficient. Underwood HiFi sells them. They also make 4 channel amps, power configured to your needs
I like fast and tight bass (often connected with SS amps),that is a priority.

This will be largely determined by the speaker. I am not familiar with your speaker but it depends how they are designed. Q=0.71 is critically damped and will sound "tight" in the bass. Anything above a Q of 1 starts to sound pretty muddy.

Bass is two things - loudness and length of notes. A powerful bass can be achieved through longer notes and less decay (underdamped) a lean or tighter bass will be created with criticial or overdamping. In our modern world of impressive bass, often some bass tightness has been traded off to achieve deep satisfying bass extension - but you will hear the effect on a well recorded acoustic kick drum (such as Sheffield Labs Track 1 of their drum track album).

SS will certainly be tighter than an amp with a high output impedance but a lot will still depend on the speaker design.
Hi Shadorne,
I agree with you.Unfortunatelly,i have no acess to data on Q factor of my speaker.I enjoyed reading your post on other thread.
I thought about the idea of the 6 same monos.I was talked out of it.Plus i heard for myself in my system that different amps work pretty good.I think there is a lot of potential in that idea.Only combining amps needs to be careful.
Treble and mid driver will be amped by a tube amp that will be built specifically for Sinfonia.That way i can combine different things.
Audiobb, any idea what the impedance curve of the woofer section looks like? That will play a big role with the amp that you choose! Have you talked to Alan about this? He should be able to help you on that one.
One of the best bass amps, and a great deal on the used market, would be from the Eagle/EKSC line. A pair of their 2 series (A, B, C) stereo amps or 400 monoblocs might be outstanding. They are fast, tight, and provide great woofer control while sounding musical without being dry and lifeless.
Hi Atma,

Nice to talk to you again.I know that impendance on each section (speaker is tri-wired) never changes more than +/- 10%.
Also,the whole speaker (if connected to one amp) acts exactly the same.8 ohm stable, +/- 10% maximum.
Seems an easy load for any amp.At least to me.
Alan said that tube amps work great in general (SET designs and Atmasphere OTLs), and also that Pass labs amps are also a great match.
He liked the idea of of 6 monos based on 320 B XLS SET.But i think bass drivers would be better with some other amp than SET.
The problem is that here in Croatia i can not listen to and evaluate a lot of gear.I bought Sinfonia only 3 days after i heard the name "Silverline" for the first time in my life.
And in amps there are many more choices...
So i am learning as much as i can for now.
I would consider Krell. Krell can definitely get a hold of those woofers and control them.
I would recommend the Innesound amps,I have the 1KW Innersound monos driving the bass section of the German Physics Loreleys speakers,4 x12in.woofers for each mono amp,the x-over is at 180 Hz,their impedance is 4 ohms,the the amp puts out 2kw at that impedance.These amps are very fast and the resulting sound in my system is excellent.I have had the Bryston's monos they do not even come close .I also had the Acoustic Reality 1001 monos,they were far superior to the Bryston's but no match to the Innersound KW.I believe there is a pair of Innersound 750 monos listed on audiogon.I never imagined how good the bass was on my speakers till I used these amps,outstanding!!
Hi, Ramy.... I hope you are doing well.

Audiobb, I'd highly recommend auditioning the Nuforce SEV2 mono amps all around (one per speaker should do).

Several years ago the standard Nuforce Ref 9 amps replaced my custom rebuilt amp which was rated at 300 wpc@8 ohm, 600wpc@4ohm and 1200wpc@2ohm and the speakers at the time were rated at a very inefficient 86db into 4 ohm load.

The 100 lbs. custom amp was noted for a number of things especially its fabulously, deep, tight, controlling, and well-defined bass.

The 7 lbs. (each) Nuforce Ref 9 amps were even deeper, tighter, more controlling, and more well-defined, but the Nuforce were also more extended, refined and plain more musical. I sold my custom amp before the Nuforce amps were even fully burned in.

One caveat to the above recommendation, I am a Nuforce dealer. FWIW, I was not a dealer of any sort when I auditioned the Nuforce amps and it was their performance that caused me to toss my hat into the ring.

Don't use a pot. I've tried a few in this situation and they just sounded ugly. Constant twiddling and never found the right setting. The really good audio pots are not the right range for this type of fine tuning. A series stereo attenuator in the 0-5k range should work for most combos. However, you could always just add another series resistor to a smaller range attenuator. Of course, this works a lot easier for RCA connections. XLR balanced means doubling up on everything. Series attenuators work well in this situation because they only raise impedance that was already compromised by parallel amps.

This kind of biamping, with different amps only tends to work well when the xover point is low, 150Hz or less.
If you want monoblocks with the convenience of a SINGLE chassis, I would consider a used Parasound HCA-3500 power amp.
The unit is fully dual-mono, has lots and lots of power and current, and even has seperate power cords for each channel!
This amp has Krell or Bryston-like bass control and power!
Look up the review of this amp in the Stereophile archives.
It talks about the bass capabilities of this amp, etc.
Highly recommended.
Thanks a lot for all your kind answers.Dalton,monoblocks are mandatory due to the short speakers cables i own.I already chose this setup along time ago.

Ngjockey,i am still considering what attenuator to use,still i am not clear on this.Your input is very helpfull.But you were right,i was considering the pots.

Ramy,your speakers seems very serious and good.I appreciatte the input.I think power is not very important for Sinfonias,anything above 50 Watt would be ok.
Audiobb, my experience has been that while you can get much greater volume levels by bi-amplifying, you also pay a big price- figuratively and literally! First, to do it right you have to use and electronic crossover. Good ones are expensive, and all of them behave not only as crossovers but also as filters for detail and impact. You also have to pay for another amplifier.

I have found the most convincing systems don't use electronic crossovers, instead the amplifier drives the speaker full-range. Otherwise you face prodigious integration issues, and the better your speaker is the more you will notice them. For example, its a lot easier to bi-amplify if you use the same type of amplifier for top and bottom, as far as integration is concerned. That could be tricky in your case where you have an SET on top.

At any rate I've never seen a bi-amplified system work right. I've seen them sound OK, and I am open to the idea that one day I'll hear one that is done right but until then I advise against it- if best possible sound quality is your goal.
Ralph, regarding your comments on bi-amplified systems, have you ever heard
the Orion system designed by Sig Linkwitz? In its intended configuration a
separate amplifier channel is used for each of the four drivers per speaker
channel. This is with an electronic crossover.

The Orion system has a very large internet following and reading Mr. Linkwitz's
site I found his design objectives closely match my listening goals. However,
I've heard two different Orion systems and was disappointed in both. I expected
the individual amp/driver configuration would have been an advantage (low
distortion?). Now, from your comments, I wonder if this could have been a
Pryso, in many bigger setups you have a source, a preamp, some sort of interconnect for all this, the amps and the speakers.

We all need the source, the interconnections, the amps and the speakers. Some people feel the preamp is not needed (separate thread for that) but one thing is dead certain: the more building blocks in the chain, the more noise, distortion and lack of bandwidth. An electronic crossover adds quite a bit of complexity. You can always hear the reduction in transparency and other colorations they bring. In addition, drivers in a speaker often require more than just the crossover- they might need some tailoring to deal with resonance, and some may benefit by having some sort of series resistance, particularly if you are driving a high efficiency speaker with a transistor amp.

These things are usually sorted out in a passive crossover, and not so often in electronic ones unless they are set up for the specific speaker, as in the case of the Dali. But as Dali owners can tell you, its crossover is a barrier to performance that must be overcome to realize all the performance the speaker is actually capable of.

If you try to biamplify without the electronic crossover, your amplifiers will not be running efficiently at all because they will have to reproduce signals that are being absorbed by a passive crossover- kindof a messy approach.

IOW it is to your advantage to keep the system simple if you can!
DACT, Marchand, Goldpoint, Acoustic-Dimension and Shallco make attenuators, Shallco being ladder type. Most have 10K versions and some have more than 24 steps. There's probably more brands I'm not aware of. Even the Placette passive is 10K, as far as I know, if you want it packaged and a remote.

Again, using either series or parallel resistors along with attenuator can increase or reduce the overall impedance.
What about shunt-type attenuator?I am thinking about ordering a pair of Endler's attenuators,connected straight into power amp(these already have RCA plug joined with them,so there is no interconnect cable to drive from preamp to power amp).Why not use these,or at least try them,and then build a similar style with Vishay S 102 for example?
Seems to me that having only one resistor in signal path is better than more of them.
Atma,why is active crossover neccesary with bi-amping?What about the passive crossover in speaker?Seems to me that each driver still gets the range it needs.
Audiobb, you can use the passive crossovers in the speaker if they are designed in such a way to allow for separate amps. The problem is that while the speaker only sees the frequencies it is supposed to, the amp still has to reproduce full-range. You get a lot more power out of the system if you have an outboard active crossover to sort that out for you.

In the case of the passive crossover allowing for bi-amplification, it does seem to sound better than using an electronic crossover. A feature of our amps is that they can be monostrapped together; this always works better than running one top and one bottom, assuming that they are the same model.
Thanks a lot Atma.Your knowledge always helps a lot.I think Sinfonia was designed for bi-amplification (actually for tri-amplification).

In the case of the passive crossover allowing for bi-amplification, it does seem to sound better than using an electronic crossover.

I thought this would be the case.
The reason for this is probably that there is one less element in the signal path.I think my speakers will work fine in multi-amp configuration,but i have to try and see.There is simply no other way.But first i need to treat the room.This is the next stage.
I'm surprised that with a thread on solid state, monoblock, and bass, the Krell name only came up once! I haven't been fortunate enough to try any of the monoblocks (KSAs or FPBs)on my speakers, but I do have a KAV-300R and it's been able to give a lil nice tightness to my maggies, which or notorious for being a lil shy on the Bass part.

The bass is something that I do miss when I swap out the SS amp and hook up my Cary Sixpacs to the speakers.

Although the Bryston 7B does seem pretty legendary in this category. If I ever come across one, I might have to audition it with my Maggies.

I think there's something to be said for Mark Levinsons also...

You never mentioned your price range?
A nice trick with Maggies, at least with tube amps, is keep the speaker cables short, really short, like maybe only 6 inches. I've heard that make a profound difference.
Price range - well,it depends.Sinfonia is tri-wired.So SS monos will drive either one 12" woofer only (one connection),either that 12" woofer plus another 12" woofer and one 7" mid-bass (other connection).

If 30 W/ch 320B XLS SET proves good/very good in bass,then i will let it drive tweeter and 2" midrange,along with one 12" and 7".
That way i will not sacrifice anything in midrange.Bass will still be suficcient if i connect a rear 12" woofer to SS amp.This woofer is configured for the deepest bass.
In that setup i will not go above 3-4 000 $ for SS monos (used).This is top,but i could also end up paying even less.For example ,Wired4Sound 250 W/8 Ohm monos seem good enough for that option.Class D shouldn't be a problem there.

But,if SET amp shows only treble and midrange good enough,that i have to go with more expensive SS amp,as it will be powering both connections (7"+12" and 12").
Then i have to spend more....Pass seems a way to go then.

I will know which way to go when the monos are built.But i have a great confidence in a man who will build them for me.
I think they will prove good enough for everything.I think that tweeter and 2" mid and 7" and front 12" will end up powered by these.I have a great respect for the knowledge of SiniĀša Trlin.I was lucky to meet him,he thought me a lot about audio.
Since there is no limit in $$ for building these,i think they will be able to stand side-by-side (or surpass) any SET amp,regardless of price.I am very curious to hear them.
Patience is a virtue.
Brystons are great for bass the 7bsst is a great call above, also although you said you don't need power, the Spectron Musician (maybe an older version) are bass monsters, I love the Mac 7270(? can't remember the exact number, it's been a while) for pure bass reproduction.

good luck
Krell Evo series...... tight, powerful bass. Krell is known for state of the art bass reproduction. The Evo's Highs and mids are smooth and accurate, then add the remarkable bass. A pair of Boulder 2050 would be my next choice.
sorry.... I did not read the post before mine where you give a price range. The Evo's and the Boulder will be considerably more than you want to spend even used.

I personally would not mix amps if by-wiring, but that's me.

I meant By-amping. Why can't you edit your responses after posted?
Agreed with Stehno's assessment fo the Nuforce Ref 9SE V2. It kicked the crap out of all previous amps I've heard or auditioned at home. Definitely worth a try. Unbelievable sound from top to bottom with absolute grace, controll and musicality
What monoblock power amp for bass ?


Now you will know what to look in amplifier to drive the bass and other "things"

Good Luck in your search
Another power amp to consider is the Symphonic Line. They have several models. These are ultra high bandwidth, transparent, fast, deep bass, beautiful midrange and silky highs. Since you are in Croatia it should be closer and cheaper for you to get one from Germany.