Anyone use solid state for the bass and valve for mid and treble [Archive]

oceanobsession

10-11-2017, 20:05

Thanks guys , my ming da 805 monoblocks technical specs are

Frequency response *18Hz–30kHz ±1dB.

Output power: **40W
Output impedance: *4Ω, 8Ω
Input sensitivity: **400mv
Input impedance: **100K
Distortion: ***≤1% at full power
Signal to noise ratio: *88dB
Power dissipation: **196W
Inputs: ***1 Gold plated RCA Phono
Outputs: ***Gold plated 4mm posts

Would it be the 400mv input sensitivity that I'm interested in , I'm driving them with a tisbury pre , cheers phil.

Yomanze

10-11-2017, 20:08

Yes you will ideally be matching the input sensitivity, or you’ll have to start messing around with attenuation.

oceanobsession

11-11-2017, 00:15

Apparently 400mv sensitivity settings is great for cd players etc giving 2v , the tisbury pre has 10 and 20 db settings on one pair of phono plugs
the hypex amp that I'm thinking about using to drive my 12 inch bass speakers are 26db gain , so now I'm getting confused , we have db and mv help phil.

Pharos

11-11-2017, 00:29

dB = 20 log V1/V2 gives the gain or loss in dB, where V1 and V2 are the two respective voltages.

But, you can simply run the output into a suitably high value potentiometer, and by suitably I mean at least 10 times greater than the output impedance of whatever feeds the pot, and then use the earth and wiper of the pot as a source to feed the following amp, the pot forming a gain control to match levels. Use a stereo log potentiometer.

I have been running my ADAMs from my ATC pre this way, using its tape outs, so that I can run my own (other) speakers as well from the normal pre out, and compare the two.

Firebottle

11-11-2017, 08:05

, so now I'm getting confused , we have db and mv help phil.

Phil, I've got measurement equipment and can match the gains for you, happy to help, no problem.

Give me a call :)

topoxforddoc

11-11-2017, 08:52

That's what some horn systems do, when they have active subs. For instance my Avantgarde Duos have passive compression drivers in separate treble and midrange horns with an active unit containing 2 x 12 inch drivers driven by solid state amps with a crossover designed and built into the system. Hence my 6W TRON Voyager 20B SET power amp drives the treble and mid, whilst the lower freqs are driven by the SS active sub.

I know that some people perceive that the active subs are a weakness in the AG design, but if you want a passive bass horn, you need a massive room, as these are BIG. To be honest if AGs are set up properly, the integration isn't bad at all and not really noticeable in normal use IMO.

paulf-2007

11-11-2017, 16:20

"....
That's what some horn systems do, when they have active subs. For instance my Avantgarde Duos have passive compression drivers in separate treble and midrange horns with an active unit containing 2 x 12 inch drivers driven by solid state amps with a crossover designed and built into the system. Hence my 6W TRON Voyager 20B SET power amp drives the treble and mid, whilst the lower freqs are driven by the SS active sub.

I know that some people perceive that the active subs are a weakness in the AG design, but if you want a passive bass horn, you need a massive room, as these are BIG. To be honest if AGs are set up properly, the integration isn't bad at all and not really noticeable in normal use IMO.the later ones are better Charlie, I went to someone's house to hear his duos and try some alternative amps in his system. He ran those kronzilla amps, about 40w I believe and it didn't sound good. We tried my 2A3 monos and 300B. I can't remember which we decided was best, but both were better than his amps. I think the kronzillas were only just off almost off on the volume control due to the horns efficiency and I believe it affected the bass too.

montesquieu

13-11-2017, 00:24

Tried this with my Tannoys - various SS amps from quad 303 to 200 class d on the bass, 300b and 2a3 SET on the horn tweeter. Also tried kt88 and 2a3 into woofer and tweeter respectively, benchmark to beat was a decent KT88 pp amp on its own.

Tried with both passive crossovers modded with l pad removed on the tweeter (matching done with the vol control on the SET amps), and with solid state active crossovers.

It was an interesting exercise that I ran over a number of weeks but the upshot was single kt88 amps and passive crossover sounded the easiest and most musical - the most ‘right’. Next came the modded passive crossovers with kt88 and SET, but it still sounded lacking somehow.

I could never get a solid state / valve mix to sound any good at all into my Tannoys though I have heard this sound good on horn systems where the SS component is just very low frequencies. (Tannoys cross over at 1 kHz which is 2 octaves above middle C - that’s too high to run SS in a mix like this. )

Wort satisfying curiosity I would say - who knows it might work on your setup. A dead end on Tannoys when I tried it - made some interesting sounds but nothing I could live with long term.

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forsell

13-11-2017, 02:43

Just wondered if anyone has used valves for mid and treble and solid state for bass , and is d technology best for bass work , are there any bass amps
with attenuators to match the valves gain , can this be done by ear . are there any down sides to this . phil.

Works only properly with all amps being same manufacturer/model because only this guarantees "same sonic characteristic" of all drivers. Even if SS amps only used -but both different- or valve amps only used but different- (>in most cases they will sound different) you will hear some sonic inconsistency across the frequency range. Matching output levels is not enough. That's why you find in all active systems same amps built inside (they only differ in power output specification) for all drivers -for example ATC active LS- which is almost the same concept but with an active crossover between preamp and amp section.

Slowly, wooly sounding amp for mid/tweeter, great PRAT-sounding amp for the woofer for example -I DO hear sonic mismatch as if 2 different speakers were playing in front of me. IMO

Pharos

13-11-2017, 09:21

First;y, the way the brain/ear interprets bass - mid - and top is very different, as are the sensual experiences of each.
Secondly, this disparity of opinion is incredibly interesting.

What I like particularly in this forum is that differing views are usually said or stated as a humble opinion, and rarely is there acrimony or poo-pooing of others' views.

BTW the ATC power packs run differing classes of amplification for each of the amps.

Firebottle

13-11-2017, 09:30

What I like particularly in this forum is that differing views are usually said or stated as a humble opinion, and rarely is there acrimony or poo-pooing of others' views.

+1
Most definitely Dennis, but all systems will sound at least 'slightly' different.

RothwellAudio

13-11-2017, 09:59

Works only properly with all amps being same manufacturer/model because only this guarantees "same sonic characteristic" of all drivers. Even if SS amps only used -but both different- or valve amps only used but different- (>in most cases they will sound different) you will hear some sonic inconsistency across the frequency range. Matching output levels is not enough. That's why you find in all active systems same amps built inside (they only differ in power output specification) for all drivers -for example ATC active LS- which is almost the same concept but with an active crossover between preamp and amp section.

Slowly, wooly sounding amp for mid/tweeter, great PRAT-sounding amp for the woofer for example -I DO hear sonic mismatch as if 2 different speakers were playing in front of me. IMO

I disagree with this entirely. An amplifier which is powering only a bass driver will have it's sonic character obscured by the fact you're only hearing half the frequency spectrum. Same goes for an amp powering just the tweeters.
The reason why active speakers use all the same amps is because it makes a lot of sense from a manufacturing point of view to make large quantities of one amp type, not have lots of different ones to faff about with.

jandl100

13-11-2017, 10:03

I've tried bi-amping with different makes and types of amps on different speakers several times.

It never works for me - it always sounds "wrong" after a short while.
It might be expectation bias, but my subjective impression has been consistent.

walpurgis

13-11-2017, 10:16

anthonyTD

13-11-2017, 10:34

Tried various combinations of diffrent amps when bi-amping, always came back to one stereo amp [or mono-blocks] doing all frequencies per side.
A...

Yomanze

13-11-2017, 14:20

Tried various combinations of diffrent amps when bi-amping, always came back to one stereo amp [or mono-blocks] doing all frequencies per side.
A...

Yep, me too, like Jerry have always found bi-amping to not sound quite right. If I had to describe it, I think bi-amping gives a more 'disjointed' and less 'coherent' sound.

anthonyTD

13-11-2017, 14:53

:)
Yep, me too, like Jerry have always found bi-amping to not sound quite right. If I had to describe it, I think bi-amping gives a more 'disjointed' and less 'coherent' sound.

montesquieu

13-11-2017, 14:55

Yep, me too, like Jerry have always found bi-amping to not sound quite right. If I had to describe it, I think bi-amping gives a more 'disjointed' and less 'coherent' sound.

That's pretty much what I was saying too. A lot of complication for no benefit.

Clive

13-11-2017, 15:54

My feeling is there are 2 primary issues.

1) the frequency of the crossover - I use a class d bass amp but only for bass below 100Hz. I have mixed this with valves for the rest of the frequency range and have been pleased with the result. Whether I'd be so pleased if crossing over at say 500Hz or 1kHz is another matter.

2) we don't all have the same priorities, it might be that you don't notice some differences in sound as the music transitions between the amps. It might be that at first you don't notice it but then some smart alec on a forum tells you what to listen for and you then can't enjoy the sound any more!

VanDerGraaf

13-11-2017, 19:12

Oddly enough I was thinking about this subject last week long before I saw this thread.

I do wonder if I would spot this lack of cohesion that some people talk about, or if I would not be aware. Small things tend to jump out at me where audio is concerned- and then there is the further question, would I in fact like the fact that the disparity would give room to "tune" a system to my personal taste.

As usual it is all about having the equipment to try it out- and there are no valves here sadly.
I'd imagine a low crossover point is best, say less than 120Hz. Even a little higher than around that is, to me, far too high into the normal/fundamental range of most material/instruments for me to imagine sonic satisfaction to be forthcoming.
I'm not really adding anything here am I? :D

In short though it is something I'd like to try.

Yomanze

13-11-2017, 19:18

Yes, my experiences are with biamping the tweeters and woofers. I would think sub 120hz is a different ballgame, with clearer benefits.

VanDerGraaf

13-11-2017, 19:51

Yeah, once you start reproducing the fundamental frequencies of instruments with one amp and the rest of their harmonics with another, it doesn't sound like it would be a great solution. Of course with a lot of instruments it can hardly be avoided....

paulf-2007

13-11-2017, 21:57

Pharos

13-11-2017, 22:59

alphaGT

14-11-2017, 02:05

I have pondered a similar situation with my big Legacy Focus’s. I had a decent Forte’ Model 3, putting out 200wpc. But my bass was weak, and it lacked punch and drive. The highs were quite pleasant, but it wasn’t cutting it. So, I borrowed a Crown, D class amp from the band’s PA putting out 450wpc, and bi-amped the speakers. The Crown has gain knobs on the front, so I used them to balance the bass and treble. Nice because I could adjust it for different recordings. But, alas, it still wasn’t what I had hoped for, still lacking punch and slam.

So I bought a Krell FPB-300, NOW! Now I’ve got it all! And am super happy with how these speakers are performing. I know that doesn’t answer your question, but I’m getting to that.

I’ve seen some multi amped speakers in the past, I can’t recall who made them, but I remember they used a digital crossover made for PA systems, a DBX or Behringer digital crossover to balance their tri-powered speakers. Between the preamp and amps. And they seem to have had great success. Showing these speakers at Audio shows, in high priced setups.

Also, there are RCA attenuators made for car audio, for this very purpose. Just resistors I assume? But you just select the amount of attenuation and insert it in line with an RCA interconnect. I don’t know what affect it may have on sound quality, but there are resistors in most internal crossovers anyway, so it may work just fine? And a fairly cheap experiment either way. Surely less affect than a potentiometer?

One thing is certain, if there’s a will there’s a way. I too have considered driving my bass with the Krell, and using a nice tube amp for the highs, just to experiment. And there is always the idea of driving your speakers with the tube amp, and having a powered sub woofer in the room, which is designed to be adjusted to match the mains. I’ve heard some very successful setups done this way. I hope this gives you some ideas!

Russell

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Ali Tait

14-11-2017, 09:24

I run my 4 way OB’s with a mix of amps via a miniDSP 4x10hd. Works extremely well to my ears. A few folk here heard them at a previous NEBO and seemed to like what they heard, though they were only 2 way at the time. Going 4 way with different drivers has made a real improvement to my ears.

I just tune by ear to music I know well- each channel’s gain and delay is adjustable with the miniDSP software.

Probably will get round to measuring them at some point, but I’m happy with the way they sound.

Firebottle

14-11-2017, 09:52

Works extremely well to my ears.

+1, exceedingly good.

RothwellAudio

14-11-2017, 10:06

I’ve seen some multi amped speakers in the past, I can’t recall who made them, but I remember they used a digital crossover made for PA systems, a DBX or Behringer digital crossover to balance their tri-powered speakers. Between the preamp and amps. And they seem to have had great success. Showing these speakers at Audio shows, in high priced setups.

Also, there are RCA attenuators made for car audio, for this very purpose. Just resistors I assume?
No, an attenuator is not just a resistor - it would be hopelessly inaccurate if it was. Even when an attenuator is a well-conceived potential divider it is affected by the source impedance and the load impedance to some extent. The source impedance is usually so low that it isn't an issue but the load impedance can be a nuisance if you need accuracy. It is possible to minimise the effects of the load impedance by making the impedance of the attenuator much lower, but doing that puts an unnecessary load on the source so I don't recommend it. The truth is that without knowing the load impedance that the attenuator will work with (ie the input impedance of the amplifier) it is difficult to get accurate attenuation within 1dB or so. It gets worse the lower the level of attenuation you're aiming for.
In short, in-line attenuators can work to even out the sensitivity discrepancy between amplifiers, but you can't really rely on the nominal value of the attenuator when you're aiming for accuracey of 2dB or better.

spendorman

14-11-2017, 10:14

Not sure if anyone has mentioned this before, apologies if they have. Perhaps one needs to consider if the two amps are phase inverting or not.

anthonyTD

14-11-2017, 10:37

Good point Alex.
And something that would indeed affect the outcome!
A...
Not sure if anyone has mentioned this before, apologies if they have. Perhaps one needs to consider if the two amps are phase inverting or not.

alphaGT

14-11-2017, 10:38

No, an attenuator is not just a resistor - it would be hopelessly inaccurate if it was. Even when an attenuator is a well-conceived potential divider it is affected by the source impedance and the load impedance to some extent. The source impedance is usually so low that it isn't an issue but the load impedance can be a nuisance if you need accuracy. It is possible to minimise the effects of the load impedance by making the impedance of the attenuator much lower, but doing that puts an unnecessary load on the source so I don't recommend it. The truth is that without knowing the load impedance that the attenuator will work with (ie the input impedance of the amplifier) it is difficult to get accurate attenuation within 1dB or so. It gets worse the lower the level of attenuation you're aiming for.
In short, in-line attenuators can work to even out the sensitivity discrepancy between amplifiers, but you can't really rely on the nominal value of the attenuator when you're aiming for accuracey of 2dB or better.

I understand what you’re saying. I guess the only way to make these inline attenuators work would be to have a wide selection, and use trial and error to find the one that works best? Even if it’s just car audio, it’s still it’s hit and miss. An active crossover is the best option.

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RothwellAudio

14-11-2017, 10:47

I understand what you’re saying. I guess the only way to make these inline attenuators work would be to have a wide selection, and use trial and error to find the one that works best?
No, there's another option - contact me and I'll make some custom attenuators to do the job properly. However, the attenuators will only give the specified level of attenuation when used with the amp they're designed for (or one with the same input impedance).

alphaGT

14-11-2017, 16:56

No, there's another option - contact me and I'll make some custom attenuators to do the job properly. However, the attenuators will only give the specified level of attenuation when used with the amp they're designed for (or one with the same input impedance).

Yes that would be the best option of all! A custom made circuit to balance the speaker’s output. But, wouldn’t that require you to be there, in person, to get the measurements needed to build it?

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RothwellAudio

15-11-2017, 09:44

Yes that would be the best option of all! A custom made circuit to balance the speaker’s output. But, wouldn’t that require you to be there, in person, to get the measurements needed to build it?

Given accurate figures for the amps' sensitivities and input impedances it's possible to use attenuators to match them. Assuming that the speakers have passive crossovers with elements to match the drivers' sensitivites, all should be fine. However, if you're starting from scratch and using amps with different sensitivities and drivers with different sensitivities then yes, you would have to make measurements to get them to work well together.

Lawrence001

15-11-2017, 23:26

I did this quite simply in a previous set up of mine with kef reference model 2s which were a beast to drive in the bass. I used a valve integrated on the mid and treble, it had a pre amp out so I took that into a Nad 370 integrated line input. I could use the volume of the Nad to adjust the bass output, having a second pre in the path had no obvious deleterious affect as it was only going below about 150hz. This was a cheap solution that probably drove the Kefs as well as a very expensive valve or hybrid amp. In fact I found that for some recordings it was useful to adjust the bass output (obvious examples being 80s pop/rock albums with not enough bass, but also a few recordings that had too much).

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oceanobsession

15-11-2017, 23:42

A big thank you to everyone who has responded with suggestions and advice , my bass speaker crosses over at 200hz so not to bad , the plate amplifiers from hypex and going active on the bass only seems the way to go , i have 3 sets of banana plugs on the drivers so it would be easy to plug
back in the passive crossover to the bass and compare with the active crossover . £350 ish 200w rms into 8 ohm , out of stock at the moment so i cant pull the trigger at the moment , me phil.

BruceActIII

26-11-2017, 23:41

So, I'm feeling like a total impostor in this crowd, but I've done something not unlike this and much simpler in my system. I have a pair of SET amps monoblocked at 10 W each - the mids and highs are sweet but the bass is (was) pretty uncontrolled with my original speakers. Last year I went with two upgrades: a set of line transmission speakers with just a 4-inch driver, and a vintage McIntosh 250 SS amp. My preamp has two sets of outputs, one now leads to the McIntosh to drive a pair of B&W 500s and a subwoofer, while the other set feeds the monoblocks/line speakers. I essentially now have two separate systems driven by the same source, superimposed. I tuned the relative volume levels and balances of each system by ear. I wasn't expecting much but wow, I now have the sweet tube sound and a very tight lower end, it really worked. (The McIntosh side does a pretty competent job on its own, but the tube enhancement pushes this into another realm to my ears.) I'm sure this is still a junior system compared to what I'm reading about on this thread but I'm really enjoying it. :)

Cheers

Bruce

walpurgis

26-11-2017, 23:43

The appreciation and enjoyment are all that matter Bruce.

paulf-2007

27-11-2017, 19:26

Yes indeed Bruce, if it sounds good to you that matters more than all the measurements in the world. Enjoy

montesquieu

27-11-2017, 19:54

Our own sensitivities and sensibilities have to come into this.

I've seen so many designers say that certain frequency ranges should not be divided across different drivers, and then another designer blatantly breaks those rules.

For eg., B Woodman states that the human voice must all be covered by one driver, (with the exception of fundamentals I suppose), which is about 300 to 3000Hz with his mid driver.

Then another designer of a new speaker has a Xover right in the middle of the vocal range, and it doesn't stand out as sounding particularly wrong.

eh? 300hz is something like D above middle C. Singing voice fundamentals range from about 70-80 hz (a good Russian bass) to about 600hz (a good Coloratura Soprano) - what you need to cover the fundamentals is something like a Tannoy Dual Concentric that runs all the way from low bass up to 800hz-1khz. That mid driver is exactly in the WRONG place.

paulf-2007

27-11-2017, 22:41

eh? 300hz is something like D above middle C. Singing voice fundamentals range from about 70-80 hz (a good Russian bass) to about 600hz (a good Coloratura Soprano) - what you need to cover the fundamentals is something like a Tannoy Dual Concentric that runs all the way from low bass up to 800hz-1khz. That mid driver is exactly in the WRONG place.
300hz - 3000hz worked for me in a 3way horn set up.

montesquieu

27-11-2017, 22:50

300hz - 3000hz worked for me in a 3way horn set up.

Nevertheless you've put a crossover right on the middle note of the piano, around the higher end of baritone vocal range and lower end of soprano, or right where the cello and violin overlap as melody instruments. Not ideal I would suggest.

Pharos

27-11-2017, 23:21

I think that B W's argument was more about getting most of the harmonics from the same driver, the fundamentals could perhaps be from a separate driver, and these the ear is less sensisitive to.

It is difficult to remember verbatim a discussion with him some 20 years ago.

montesquieu

27-11-2017, 23:24

oceanobsession

13-01-2018, 19:18

Hi again folks , I ended up buying a monocor sta800d amp £300 , these use all hypex modules , and you cant buy the parts for this money so a bit of a
bargain I think , I managed to match the gain using a multi metre on ac , and used both volume controls on the sta800d to match the gain of the ming da 805 mono blocks , I had to separate the bass crossover from the mid and tweeter section , and all is now working great , after listening to a lot of
well known tracks it has given the bass more punch and drive , and I think the extra current that the mid and tweeter are now getting has improved
as well , i did try the amp running the whole system but its not for me , but doing bass duties only its great . hopefully my views wont change . phil

paulf-2007

13-01-2018, 20:39

:thumbsup:
Hi again folks , I ended up buying a monocor sta800d amp £300 , these use all hypex modules , and you cant buy the parts for this money so a bit of a
bargain I think , I managed to match the gain using a multi metre on ac , and used both volume controls on the sta800d to match the gain of the ming da 805 mono blocks , I had to separate the bass crossover from the mid and tweeter section , and all is now working great , after listening to a lot of
well known tracks it has given the bass more punch and drive , and I think the extra current that the mid and tweeter are now getting has improved
as well , i did try the amp running the whole system but its not for me , but doing bass duties only its great . hopefully my views wont change . phil:thumbsup::thumbsup::thumbsup: