[Wookii]

Originally Posted by AngelEyes

Are you going for 11000SE+TurboNutter?

Adam

Hmmmm . . . . Yes, I have a little confession to make . . . Three 11000SE's have been mysteriously added to my order from Bob (I blame the impetuous Mr Hyde!) - he never mentioned anything about a turbonutter being an option though! besides which, I'd have no where to store any NOS tanks!

[Wookii]

Originally Posted by rigman

The link you posted on the cap shootout was very interesting. I have the V cap OIMP type and it would interesting to compare them to the teflon.

However the 400 hour break in period is a lot of time spent not listening to them at their best. Does break in even work or is it just a myth and more like getting used to the sound.

It also states they have a sonic signature. Does that mean it colours the sound and therefore the amp is not truly transparent. so therefore my cheaper amp is more transparent

I am deliberating at the moment what to get for my new B&W diamonds on a 2 channel system. I want 600wpc and wondering if that should be 2 x monoblocks, a 2 channel and all variations of standard with upgraded caps and SE editions etc etc.

Decisions decisions.

'Allegedly' all electronics and cables need 'burning in' to sound their best - but that whole theory is probably best put in the box marked 'Lets Not Get Into That' - the same place we store cable debates and bi-wiring discussions etc

As for capacitors, my understanding is that capacitors are a necessary evil. As such the reference point against which any capacitor is measured is plain wire; the basis on how a capacitor is judged therefore, is not what a it adds to an electronic component, but how little it takes away. The V-Cap Teflon capacitors appear to be well reviewed as minimising the negative effect capacitors can have on an amplifier circuit.

All that said, as with many things audio, whether any of us could blind test the difference in one capacitor versus another is entirely up for debate.

As for myself, I am your classic 'fence sitter'. I don't claim to be able to spot audible difference between one AV tweak and another, but I make the tweaks none the less (and within the limits of what I can afford), partly because it is a hobby and I enjoy doing it, and partly in the hope that the sum of the changes gives me the best system I can engineer. The same applies to the V-Caps.

As for your new stereo set-up, congrats, how did you get that authorised by the other half? You are in a unique position to be able to audition your existing 3800 with the Diamonds, to see if AB monoblocs or another brand of amps are the best match.

Do you have any home auditions of other amps planned?

[AngelEyes]

Good grief, 3 x 11000SEs will takes some beating.

Congratulations to you and Nick on your recent purchases, I hope you will be as happy as I continue to be with mine.

Adam

[rigman]

Originally Posted by gdavies09031977

'Allegedly' all electronics and cables need 'burning in' to sound their best - but that whole theory is probably best put in the box marked 'Lets Not Get Into That' - the same place we store cable debates and bi-wiring discussions etc

As for capacitors, my understanding is that capacitors are a necessary evil. As such the reference point against which any capacitor is measured is plain wire; the basis on how a capacitor is judged therefore, is not what a it adds to an electronic component, but how little it takes away. The V-Cap Teflon capacitors appear to be well reviewed as minimising the negative effect capacitors can have on an amplifier circuit.

All that said, as with many things audio, whether any of us could blind test the difference in one capacitor versus another is entirely up for debate.

As for your new stereo set-up, congrats, how did you get that authorised by the other half? You are in a unique position to be able to audition your existing 3800 with the Diamonds, to see if AB monoblocs or another brand of amps are the best match.

Do you have any home auditions of other amps planned?

Yes lets not go there forgive it was just me trying to get a bite hence the devil

I have a 6400 (not a 3800) and briefly hooked 2 channels up a few days ago to the diamonds. Excellent sound. I then put it back to full cinema duty and hooked up and old Audiolab 8000A and it is as dull as dishwater.

I was also going to buy a used Musical Fidelity muscle amp to tide me over in the meantime and then I can do a direct comparison with the AB and decide from there. I have always liked the MF valve sound having owned Nuvista gear for many years with my old hifi. I figured if the AB is better I can sell the MF and not lose too much and then decide which AB(s) to go for. Keep the options open.

Congrats on the 11000SE's. Just watch you dont pop them M&K's though

[mykyll2727]

Originally Posted by gdavies09031977

Hmmmm . . . . Yes, I have a little confession to make . . . Three 11000SE's have been mysteriously added to my order from Bob (I blame the impetuous Mr Hyde!) - he never mentioned anything about a turbonutter being an option though! besides which, I'd have no where to store any NOS tanks!

Congrats!!! I'm anxiously awaiting your review if your new amps!! Will you be posting some pics? Hopefully?

[Wookii]

Originally Posted by AngelEyes

Good grief, 3 x 11000SEs will takes some beating.

Congratulations to you and Nick on your recent purchases, I hope you will be as happy as I continue to be with mine.

Adam

Thanks Adam,

I've got a sneaking suspicion they are going to be great.

We all have you to thank/blame* for this recent spat of upgradeitis! (* - delete as appropriate)

No, but in all seriousness, many thanks for putting me onto these AB amps.

Cheers,

Gareth

[Wookii]

Originally Posted by rigman

Yes lets not go there forgive it was just me trying to get a bite hence the devil

Oh, I see! No worries, I don't tend to bite - I'm a lover not a fighter!

Originally Posted by rigman

I have a 6400 (not a 3800) and briefly hooked 2 channels up a few days ago to the diamonds. Excellent sound.

Sorry, yes, you've two 6400's I forgot. Did you bridge it into the Diamonds?

Originally Posted by rigman

I then put it back to full cinema duty and hooked up and old Audiolab 8000A and it is as dull as dishwater.

That's interesting to hear. I had considered the Audio lab amps myself before Adam put me into these amps - they have a good reputation at their price point, so it's interesting to hear a direct comparison review like that!

Originally Posted by rigman

I was also going to buy a used Musical Fidelity muscle amp to tide me over in the meantime and then I can do a direct comparison with the AB and decide from there. I have always liked the MF valve sound having owned Nuvista gear for many years with my old hifi. I figured if the AB is better I can sell the MF and not lose too much and then decide which AB(s) to go for. Keep the options open.

Sounds like a good plan Darren - I havent heard MF gear myself, but I have read very good things about them, and they do seem to hold value.

Are your systems not close enough to use a speaker switch at the back of your 6400?

Originally Posted by rigman

Congrats on the 11000SE's. Just watch you dont pop them M&K's though

I certainly hope not! I'm assured that there is no danger of that!

[djnickm]

Thanks chaps... But main thanks to adam for his continued love of his amps. Putting another product into my line of sight.

Bob is brilliant. For a start he is an excellent sales man. Only selling what you need. I was interested in the mono blocks but space was is a issue for me and bob assured me that actually the 3500 would be more than enough for the 802d speakers. So I went with his advice.

And then I said se them both to make them the best they can be. Upto a 12 week waiting time.... Long but hopefully worth it.

[Wookii]

Originally Posted by mykyll2727

Congrats!!! I'm anxiously awaiting your review if your new amps!! Will you be posting some pics? Hopefully?

Cheers! Will definitely post up some pics. I felt a right geek asking Bob for some mid-build pics too, but as he agreed that he's a geek too, I didn't feel quite such a prat for asking for pictures of capacitors!

I will definitely be doing a full review once I receive the amps - I'll be booking a whole day out to do some A-B Comparisons with my current Sunfire amp.

[AngelEyes]

What are you planning to upgrade the M&Ks to in the future? Far be it for me to suggest an amp is overkill given my history but an 11000SE for a sat speaker is taking things to another level

Adam

[Wookii]

Originally Posted by djnickm

Thanks chaps... But main thanks to adam for his continued love of his amps. Putting another product into my line of sight.

Bob is brilliant. For a start he is an excellent sales man. Only selling what you need. I was interested in the mono blocks but space was is a issue for me and bob assured me that actually the 3500 would be more than enough for the 802d speakers. So I went with his advice.

And then I said se them both to make them the best they can be. Upto a 12 week waiting time.... Long but hopefully worth it.

Yeah, I absolutely agree, Bob has been a pleasure to deal with. If only everyone in the AV industry had his approach!

[Black Tarantula]

Originally Posted by gdavies09031977

Yeah, I absolutely agree, Bob has been a pleasure to deal with. If only everyone in the AV industry had his approach!

I must say I have done a lot of research on these amps and eat my words, they sound truly phenominal.. What's you current set up - any pics, cheers.

[djnickm]

Who went for the upgraded power cables? Another can of worms?

I am hoping to do an ab ( excuse the pun) comparison with the Ada 8150 biamped.

Best thing for me tho and most importantly, Bob is able to leave the fans out of my builds. He says they are not required for the 3500. 6500 yes, but not the 3500 or 4200 so that is a good thing.

Adam, I hope you get a free amp out of all these sales you have created.

[rigman]

Originally Posted by gdavies09031977

That's interesting to hear. I had considered the Audio lab amps myself before Adam put me into these amps - they have a good reputation at their price point, so it's interesting to hear a direct comparison review like that!

Are your systems not close enough to use a speaker switch at the back of your 6400?

I spent the morning doing a few mods and wire rerouting. I have now utilised 2 channels of my 6400 for hifi duty. I had biamped my 3 fronts so now just the centre is biamped and the L&R are single amp.

I then did some fancy cable routing to the diamonds. The difference is literally night and day compared with the Audiolab. I was grinning all afternoon as my favourite tunes were given the power and control they deserved.

The preamp I have been using is a NJC Monitor 2 headphone amp that I had bought to use with my Sennheisers. The website says it is also was a high quality preamp but I was sceptical. However I have to admit it is very very good and is giving me second thoughts on getting the Musical Fidelity. The only downside is that it only has one input.

So I need to decide on which flavour of AB now

[Wookii]

Originally Posted by AngelEyes

What are you planning to upgrade the M&Ks to in the future? Far be it for me to suggest an amp is overkill given my history but an 11000SE for a sat speaker is taking things to another level

Adam

Well, yeah, sure, it is overkill of course , but despite the MK's being sat speakers - due to their lower sensitivity, they do have higher than usual power requirements, and are rated up to 400W at 4 ohms, which (if my basic understanding of these things is correct - feel free to correct me if its not) is a much more demanding load, than say a full range speaker that is rated up to 200W at 8ohms requirements.

My main reason for getting the monoblocs was to eek out every last possible ounce of sound quality - on the assumption that one amp board per chassis, being powered by one independent oversized transformer and power supply, will enable lower SNR and THD, together greater current availability to maximise dynamics These are all assumptions of course! - but Bob seemed to agree the the monoblocs would be the pinnacle of his amp ranges - which makes sense as this is the case with most amp manufacturers.

The fact that I decided on the 11000 rather than one of the lower powered monoblocs, was more just a case that I wanted to be sure that all possible future speaker upgrade options would be covered. Much like yourself, I want these to be the last home cinema amps I buy.

In terms of further speaker upgrades, that is a couple of years off at this point, but currently on the shortlist are (after having spoken to Darren about his speakers) JBL SK2-3300's, and Focal Utopia III Viva's . I'm more than open to suggestions for alternatives though as I haven't really started looking?

[Wookii]

Originally Posted by Black Tarantula

I must say I have done a lot of research on these amps and eat my words, they sound truly phenominal.. What's you current set up - any pics, cheers.

My current set-up is in my sig - its all currently in a dual purpose room - lounge by day, home cinema by night, but our planned extension next year will at last allow me to turn the lounge over to a dedicated HC - I've waited 10 years already, so another year-18 months can't hurt

Once I have full control of the room from the better half, the WAF will no longer apply, so the room will be gutted with plasterboard removed, fully sound-proofed to all walls and ceiling, will have multiple dedicated mains spurs added, will be acoustically treated, and no doubt covered in copious amounts of devore black velvet. When I get to that stage I'll probably start up my own thread in the DIY section, if for no other reason than to document it for myself!

[Wookii]

Originally Posted by djnickm

Who went for the upgraded power cables? Another can of worms?

I am hoping to do an ab ( excuse the pun) comparison with the Ada 8150 biamped.

Best thing for me tho and most importantly, Bob is able to leave the fans out of my builds. He says they are not required for the 3500. 6500 yes, but not the 3500 or 4200 so that is a good thing.

Adam, I hope you get a free amp out of all these sales you have created.

I've had mine without any power cables to be honest, I prefer to make them myself, I think you end up getting a lot more for your money.

I just use one of these high current plugs: Wattgate, with one of these UK wall plugs: MK Toughplug, and some of this cable: Furutech (which is also available from TM3 Connection, but is not listed on their website), combined with a few ferrites for EMI suppression (again, allegedly!), some heat shrink and braiding. You end up with high spec good looking cable for a fraction of the cost.

Its all screw fit throughout, so no soldering unless you want to, and is dead easy to make (though the cable is quite substantial, its a little like wrestling a python trying to get it into the MK Toughplug!)

[Wookii]

Originally Posted by rigman

I spent the morning doing a few mods and wire rerouting. I have not utilised 2 channels of my 6400 for hifi duty. I had biamped my 3 fronts so now just the centre is biamped and the L&R are single amp.

I then did some fancy cable routing to the diamonds. The difference is literally night and day compared with the Audiolab. I was grinning all afternoon as my favourite tunes were given the power and control they deserved.

Superb! I did wonder if you had already thought of that as a solution until you decide what to do get to permanently drive the Diamonds.

By the way, what made you settle on the Diamonds, did you try out another other speakers before settling on those? They are on my short list for a potential future stereo set-up, so I'm interested if you tried/eliminated any other models in the process?

Originally Posted by rigman

The preamp I have been using is a NJC Monitor 2 headphone amp that I had bought to use with my Sennheisers. The website says it is also was a high quality preamp but I was sceptical. However I have to admit it is very very good and is giving me second thoughts on getting the Musical Fidelity. The only downside is that it only has one input.

Without wishing to teach you to suck eggs here Darren, can you not utilise the additional zones in the D2v in any way? Its got great DAC's in it, and its analogue pass-through is supposed to be better still!

Originally Posted by rigman

So I need to decide on which flavour of AB now

If space isn't an issue, get the monoblocs! You know you want to!

[AngelEyes]

Originally Posted by gdavies09031977

Well, yeah, sure, it is overkill of course , but despite the MK's being sat speakers - due to their lower sensitivity, they do have higher than usual power requirements, and are rated up to 400W at 4 ohms, which (if my basic understanding of these things is correct - feel free to correct me if its not) is a much more demanding load, than say a full range speaker that is rated up to 200W at 8ohms requirements.

The 150s are a 4 Ohm load as you mention but with a roll-off at around 80-100Hz they are not the heavy load you might think, they are also pretty sensitive.

They have always been talked up as a 'difficult to drive' speaker but that started a long time ago and I would argue that is a pretty moot point given the power of modern amps.

I would expect a full range speaker rated 6-8Ohms to present a bigger load than 4Ohm satellites with no bass extension because bass is where most of the power is required. This is just my feeling based on brief possession of a pair of S150s, I have no empirical data to prove one way or the other.

That is not to say they won't benefit from great amps attached particularly in terms of dynamics, low noise floor etc. but I would be very interested hear what kind of improvements you feel you get from those epic ABs attached to the M&Ks. My guess is like me with my feeble 500W per channel, you will find yourself leaping off the sofa like a frightened schoolgirl during CBeebies etc. lol

I am dead jealous you know!

Adam

[rigman]

Originally Posted by gdavies09031977

Superb! I did wonder if you had already thought of that as a solution until you decide what to do get to permanently drive the Diamonds.

By the way, what made you settle on the Diamonds, did you try out another other speakers before settling on those? They are on my short list for a potential future stereo set-up, so I'm interested if you tried/eliminated any other models in the process?

I have always liked them. I have intended to buy every incarnation of the 802 since the Nautilus. However I have always been tempted away at the 11th hour. The last time was being the offer of the JBL's which was too good to refuse.

Without wishing to teach you to suck eggs here Darren, can you not utilise the additional zones in the D2v in any way? Its got great DAC's in it, and its analogue pass-through is supposed to be better still!

IIRC the other zones of the D2V have higher distortion than the main zone even higher than the NJC. I thought the analogue bypass would only come through the amin zone which would mean swapping cables about to listen to music. I cannot be bothered with all that.

If space isn't an issue, get the monoblocs! You know you want to!

The AB's sound superb. However no offence to Bob is he is watching but they are not the prettiest pieces of kit in the world. They are okay hidden in a rack in a dark corner of a cinema room but on show in a main living room is another thing. One amp is easier to hide than two.

[Wookii]

Originally Posted by AngelEyes

The 150s are a 4 Ohm load as you mention but with a roll-off at around 80-100Hz they are not the heavy load you might think, they are also pretty sensitive.

They have always been talked up as a 'difficult to drive' speaker but that started a long time ago and I would argue that is a pretty moot point given the power of modern amps.

I would expect a full range speaker rated 6-8Ohms to present a bigger load than 4Ohm satellites with no bass extension because bass is where most of the power is required. This is just my feeling based on brief possession of a pair of S150s, I have no empirical data to prove one way or the other.

That is not to say they won't benefit from great amps attached particularly in terms of dynamics, low noise floor etc. but I would be very interested hear what kind of improvements you feel you get from those epic ABs attached to the M&Ks.

You are more than likely right Adam, you know much more about these things than I ever will.

I was just working on the basis that a 4ohm speaker draws double the current to an 8ohm speaker and a 400W requirement into 4ohms is equivalent to 800W into 8 ohms. The sensitivity is around 88dB from memory, so they would require twice the amplifier power to achieve the same SPL as a 91db sensitivity speaker. But I only have a very loose understanding of these things.

But you are right of course, moving big bass drivers more than liklely requires more power than a speaker that cut's off at 80Hz.

Originally Posted by AngelEyes

My guess is like me with my feeble 500W per channel, you will find yourself leaping off the sofa like a frightened schoolgirl during CBeebies etc. lol

Feeble 500W! Adam, your amp kicks ass! Do you not bi-amp your front three anyway? If so you are delivering 1000W (at 8ohms) into each of your front three speakers in any case, with an independent power supply for each channel - which is largely the same as the 11000's!

Bi-amping isn't an option for me (only one set of binding posts!), neither is bridging because they are 4ohm speakers, which is part of the reason I went with the monoblocs.

I'm looking forward to being scared off my sofa during CBeebies - though to be honest 'In The Night Garden' freaks me out enough already!

Originally Posted by AngelEyes

I am dead jealous you know!

Adam

You have nothing to be jealous about Adam, you have an amazing system! The other day I stumbled across your DIY sub-woofer thread with those luscious curved cabinets!! My wife is not going to be happy with you for that one!! (Not to worry though, she's currently 6 days overdue with our second child so you'll easily out run her! )

[AngelEyes]

Originally Posted by gdavies09031977

I was just working on the basis that a 4ohm speaker draws double the current to an 8ohm speaker and a 400W requirement into 4ohms is equivalent to 800W into 8 ohms.

Actually I think that works the other way round (although it confuses me too sometimes), if an amp can provide 200W into 8 Ohms, in a perfect world it will provide 400W into 4 Ohms but that rarely happens in reality.

I am sure more than a few manufacturers that claim this doubling up probably just under rate the 8Ohm performance

Oh and I was being a bit facetious with my feeble comment, it is plenty for my needs.

I have recently stopped bi-amping (was considering going 7.1 again...) and haven't really noticed much of a change. I may put it back at some point to see if I can tell the difference.


Adam

[SD Viewer]

Originally Posted by AngelEyes

I have recently stopped bi-amping (was considering going 7.1 again...) and haven't really noticed much of a change. I may put it back at some point to see if I can tell the difference.


Adam

That's a relief as although I couldn't resist the upgrade to SE spec for my 5500 order I hoped I wouldn't regret sticking to "mono-amping(?)". Given the scary price of processors (a pity the 8200AP doesn't do HD) my budget is going to be stretched to the max as it is. Also indebted to Adam for pointing me in the direction of these amps.

[AngelEyes]

8200AP does do HD, it doesn't accept bitstream but it does accept LPCM. Most BD players output HD LPCM so you are good to go.

Some media players such as popcorn hour don't though. In that situation and budget I would look at Rotel or Marantz.

Adam

[rigman]

I switched 2 channels of my 6 to hifi speaker duty yesterday therefore single amping the L&R and leaving the centre bi amped.
When I went to watch a movie last night I noticed a massive difference.....

I then realised I have forgotten to switch the inputs back to XLR so had no sound from the L&R

Once I switched it over I also heard no difference between biamp and single amp.

However I suppose unless you have watched the film many many times then how would you know unless you spend a night A/B ing between the 2 setups. In my case it would mean dismantling the screen wall just to swap over. The movie last night sounded just as clear and dynamic as any other film I have watched.

Hifi is different as you normally listen to favourite albums many times so know how they have sounded on inferior equipment. You can instantly tell if it sound better or not with equipment changes.

As the tweeter and midrange take far less power than the woofers can you biamp with a lower power anp on the tweeter than the woofer say a 200 tweeter / 400 woofer?

[Welwynnick]

Originally Posted by AngelEyes

The 150s are a 4 Ohm load as you mention but with a roll-off at around 80-100Hz they are not the heavy load you might think, they are also pretty sensitive.

They have always been talked up as a 'difficult to drive' speaker but that started a long time ago and I would argue that is a pretty moot point given the power of modern amps.

I would expect a full range speaker rated 6-8Ohms to present a bigger load than 4Ohm satellites with no bass extension because bass is where most of the power is required. This is just my feeling based on brief possession of a pair of S150s, I have no empirical data to prove one way or the other.

Originally Posted by gdavies09031977

I was just working on the basis that a 4ohm speaker draws double the current to an 8ohm speaker and a 400W requirement into 4ohms is equivalent to 800W into 8 ohms. The sensitivity is around 88dB from memory, so they would require twice the amplifier power to achieve the same SPL as a 91db sensitivity speaker. But I only have a very loose understanding of these things.

But you are right of course, moving big bass drivers more than liklely requires more power than a speaker that cut's off at 80Hz.

Yes, 4 ohm speakers will draw twice as much current, and hence power, than 8 ohm speakers. P = (V*V)/R. However, that assumes the amp is perfect, and can achieve 100% doubling down (most achieve no more than 75%).

However, I don't think small speakers are easier loads just because they generate less bass. Its a common perception, but normal dynamic speakers (excluding infinite baffle, active sub, transmission line etc) use no more power for bass than other frequencies. Yes, they have to move more air, but that air moves more slowly, and they have more time to move it within each cycle. You could say that more energy is required for each cycle, but each cycle takes more time, and the power within that cycle is the same.

If anything, a small speaker is likely to be a difficult load, as they're often tuned to extend bass at the expense of efficiency, so they need more power for a given loudness.

Nick

[Welwynnick]

Originally Posted by djnickm

Hehe, thanks guys.

I have gone for a 3500se for the fronts and a 4200se for the rears and sides.

Sold my denon amp and my old naim 2 channel system. Luckily marriage remains intact.

Good move, Nick.

I know you were very keen on your big Denon, so I'll be very interested to hear what you make of the ABs. I don't think you'll be disappointed. IIRC the Cinepros were the only powers amps that I bought into twice. Marvellous amps, especially in a world that has blinkers for Canada.

All the best, Nick

[AngelEyes]

Originally Posted by Welwynnick

Yes, 4 ohm speakers will draw twice as much current, and hence power, than 8 ohm speakers. P = (V*V)/R. However, that assumes the amp is perfect, and can achieve 100% doubling down (most achieve no more than 75%).

However, I don't think small speakers are easier loads just because they generate less bass. Its a common perception, but normal dynamic speakers (excluding infinite baffle, active sub, transmission line etc) use no more power for bass than other frequencies. Yes, they have to move more air, but that air moves more slowly, and they have more time to move it within each cycle. You could say that more energy is required for each cycle, but each cycle takes more time, and the power within that cycle is the same.

If anything, a small speaker is likely to be a difficult load, as they're often tuned to extend bass at the expense of efficiency, so they need more power for a given loudness.

Nick

You know a lot more about this stuff than me but taking an example where components are properly matched, it seems every active speaker I have seen has a higher rated bass driver and amp than the tweeter which seems to imply bass reproduction is where the harder work is? Certainly from my own dabbles in speaker and sub design, the further south you push the more power you seem to consume and at a non-linear rate.

I find it hard to understand why a speaker designed to roll off at 100Hz (even a 4Ohm one) would need more power than one that is reaching 40hz? However like I said, I haven't actually done the maths.

Adam

[Welwynnick]

Originally Posted by AngelEyes

it seems every active speaker I have seen has a higher rated bass driver and amp than the tweeter which seems to imply bass reproduction is where the harder work is?

Yes! But there are several good reasons why that should be.

Firstly, I was careful to separate active speakers as a special case. Meridian, Mackie, Genelec and the like are designed for real world use, not test signals. Actual music and soundtracks don’t have an even spectral power distribution: there is simply more sound per octave in the mid and bass than at the top end. So there’s no need for a powerful tweeter amp – the money is better spent elsewhere – or you may have the option of using an amp that runs deeper into class A, for example.

Secondly, there’s no need to balance the sensitivity or power of active drive units. In fact, this is one of their advantages. Speaker design is an incredible collection of compromises, and actives free you from some of those compromises. Since you can have whatever amp gain you want, you’re free to use drivers with any sensitivity you want, and there are often advantages in using a driver with less sensitivity than the tweeter.

Thirdly, bass drivers usually handle a higher proportion of the bandwidth than tweeters. Bass drivers cover say, 50Hz to 2kHz, and tweeters from 2kHz to 20kHz. So that’s around five octaves vs three. So the bass amp would need more power even if the drive units did have the same efficiency, AND the music had a balanced spectral distribution.

Fourthly, active speakers can use equalization to give a flatter response, or to extend the response. Active subs certainly do this, and though I don’t know for sure, I suspect that full-range actives do this as well. This means putting more power in a part of the frequency range where the driver is giving less output than you want. That obviously increases the power requirement, and if you use this to compensate for deliberately using a small box, then you need a LOT more power.

Finally, even passive speakers often use padding resistors on the tweeter cross-over, in order to match levels. Tweeters tend to have a few dB more sensitivity than bass drivers, but only a few dB, mind. There’s no need to attenuate tweeters with active speakers – you just use an amp with less gain and less power.

There are many other issues as well, but I’ll have to come back.

Nick

[AngelEyes]

Thanks Nick, I seem to have a habit of choosing bad examples/analogies

Adam