XTZ AP-100 Power Amp Review in HiFi Choice [Archive]

audiosanctum

29-08-2010, 22:06

The recently launched XTZ AP-100 Class A Power Amplifier has been reviewed in the October edition of HiFi Choice magazine.

Here are some comments from the reviewer Richard Black:

"Construction is very solid.. which provides screening between input, power supply and two power amp circuit boards."

"It's lively and full-bodied and it can do some lovely subtle things with quiter tracks."

"There is not much around that we can compare this amp to directly, at least not in the way of power amps, but among integrated models it competes with favourites from Creek, Cambridge Audo, Arcam and so on. That it does so, while retaining it's own character - and it's mode-switching feature too - is admirable."

Overall HiFi Choice gvae the AP-100 4 stars of 5.

The Unit retails for just £515.00.

More information regarding the XTZ AP-100 can be viewed by clicking below:

http://www.audiosanctum.co.uk/Power-Amplifiers.html

http://www.audiosanctum.co.uk/components/com_virtuemart/shop_image/product/XTZ_Class_A_100__4b1149a9c5494.jpg

Reid Malenfant

30-08-2010, 15:24

Sorry but i'd be very interested in some more information on this amp that i can't seem to find?

Specs say it'll do 50W RMS in class A into 8ohm, fine so far...Then it goes on to state that it can produce 110W RMS into 8ohm class AB, all well & good.

The thing that i'm not quite understanding though is the mention of 4 transistors per channel. Here are my reasons for wondering how this is done.

With a 50W Class A amp the power supply will need to be at least +/- 30V if not a tad more due to component losses & voltage sag on the PSU capacitors, so lets say +/- 35V to take these into account as we need 20V RMS or if you like 28.28V peak.

Class A at 50W 8ohms requires a 1.25Amp quiescent current & with +/- 35V that will be a dissipation of 87.5W over the 4 transistors or approximately 22W each. That's not too bad.

However unless the amp is switching between two different rails it starts to look a lot worse. At 110W 8ohm you'll need rails of approximately +/- 49V & with the same 1.25A quiescent these 4 transistors will be dissipating 122.5W or nearly 31W per transistor. 29.66V RMS & 41.94V peak.

That's not so good unless some seriously high power transistors are used in the output stage.

So can i ask exactly what transistors are used on the outputs? I'm also assuming that each side of the amp from front to back will basically be heatsink of the large heavily finned variety :scratch:

Thanks in advance :)

audiosanctum

31-08-2010, 12:05

Hello Mark,

Thank you for the questions.

The output stage uses a sliding bias arrangment to reach 50 watts of class A output without ending up with fried transistors. They are Toshiba 2SC5200/2SA1943 by the way. This way the quiescent current can be kept lower, still not leaving class A mode because of the sliding bias circuit that ensures the bias current never cuts out completely during the opposite half way.

audiosanctum

31-08-2010, 12:06

I forgot to add that there are heatsinks on both sides of the case all the way down each side to aid cooling.

Reid Malenfant

31-08-2010, 14:37

Many thanks for the reply :) Is there anywhere in Cambridgeshire that has these amps in stock or am i asking a daft question :eyebrows:

I wouldn't mind getting a listen to one in reality ;)

audiosanctum

31-08-2010, 14:54

We are the UK exclusive retailer of XTZ products (XTZ has only one retailer per country and cuts out the distributor to keep the price of the products down).

If you would like to demo one we can send our demo unit out to you which you can try for a few weeks. If you like what you hear we will send you a new unit over. All we ask is a deposit of £250.00. If you like the unit we will ship the demo item back, take the balance from you and ship out a new unit. As the total cost is over £500.00 there is free shipping.

If you decide the amp isn't for you then we will ship the demo unit back and refund you the deposit minus shipping costs which would be £45.00.

This demo facility is used by 50% of our customers and i would say 90% of them decide to go for whatever they have demo'ed.

Reid Malenfant

31-08-2010, 15:00

Interesting, i quite like this idea :)

I'm assuming you'll be on the forum for a while & not run away for at least a few months? I need to get a set of speakers together that will run off of a single stereo power amp before i entertain the idea. That shouldn't be too long i'm hoping in which case i'll then get in touch & get something arranged :smoking:

audiosanctum

31-08-2010, 15:55

We will certainly try our best to maintain contact on here. We will keep the forum updated with any reviews or new products so you can contact us through here or send us PM or you can email us on info@audiosanctum.co.uk.

captain

31-08-2010, 16:19

Could you tell me if the D-100 integrated Amplifier has balance control.

Thanks

Alex_UK

31-08-2010, 16:28

If you would like to demo one we can send our demo unit out to you which you can try for a few weeks. If you like what you hear we will send you a new unit over. All we ask is a deposit of £250.00. If you like the unit we will ship the demo item back, take the balance from you and ship out a new unit. As the total cost is over £500.00 there is free shipping.

If you decide the amp isn't for you then we will ship the demo unit back and refund you the deposit minus shipping costs which would be £45.00.

Also an excellent idea if you are needing to sell an existing amp to part-pay for the new one - should be able to decide if you like it and sell the old one before you need to pay for the new one.

Reid Malenfant

31-08-2010, 16:55

StanleyB

31-08-2010, 20:48

The output stage uses a sliding bias arrangment to reach 50 watts of class A output without ending up with fried transistors. .
That's a very good method. I first saw it used in the first Super-AA power amp from Technics.
A UK engineer by the name of Drake also developed such a design, which was regularly advertised as a building block similar to the ILP audio amp blocks. He started a company called Drake Electronics, but he sadly died somewhere around 1990.
I loved the sound of the sliding class A made out of discrete transistors ( the power IC versions are terrible sounding in comparison ) and would be most interested in trying out one of these amps at some stage with the intention to buy. If it is anything like the Drake design you could be onto a winner with it.

audiosanctum

31-08-2010, 21:16

Could you tell me if the D-100 integrated Amplifier has balance control.

There is no balance control. The aim is to keep the signal as pure as possible and this isn't possible if you have a balance control in the signal path.

I loved the sound of the sliding class A made out of discrete transistors ( the power IC versions are terrible sounding in comparison ) and would be most interested in trying out one of these amps at some stage with the intention to buy. If it is anything like the Drake design you could be onto a winner with it.

The integrated amp and the power amps use the same methology and we have them both available for demonstration. Just email or PM us if it something you would like to set up.

Alex_UK

31-08-2010, 21:36

That's a very good method. I first saw it used in the first Super-AA power amp from Technics.
A UK engineer by the name of Drake also developed such a design, which was regularly advertised as a building block similar to the ILP audio amp blocks. He started a company called Drake Electronics, but he sadly died somewhere around 1990.
I loved the sound of the sliding class A made out of discrete transistors ( the power IC versions are terrible sounding in comparison ) and would be most interested in trying out one of these amps at some stage with the intention to buy. If it is anything like the Drake design you could be onto a winner with it.

You're not helping, Stan - when someone like you endorses the methodology behind something that has already got my radar running crazy, I just know I'm going to get myself in trouble with the missus any time soon... The last time was when I got the Caiman last year! ;)

Techno Commander

31-08-2010, 23:48

I must admit, they do look rather good.

I had a worryingly clever idea earlier that combined both the integrated and the power amp with an active crossover. :eek:

audiosanctum

01-09-2010, 07:55

The Integrated can also be used as a Pre-Amp as it connections on the back so you can use the pre outs only. So if you wanted to run a really good system for relatively low cost you could use an Integrated A-100D3 as the Pre Amp then you could use a pair of AP-100 Power Amps in bridged mode so that they are basically running as mono blocks getting you 350W per Channel in 8ohm and 500W per Channel in 4ohm.

A pair of AP-100's and a A-100D3 would set you back just £1630.00. That's a lot of control and power for very little outlay. Plus all the reviewers are overwhelmed by the sound and build quality from both units.

Tempted?! ;)

Reid Malenfant

01-09-2010, 10:35

The Integrated can also be used as a Pre-Amp as it connections on the back so you can use the pre outs only. So if you wanted to run a really good system for relatively low cost you could use an Integrated A-100D3 as the Pre Amp then you could use a pair of AP-100 Power Amps in bridged mode so that they are basically running as mono blocks getting you 350W per Channel in 8ohm and 500W per Channel in 4ohm.
Or as a cheaper alternative you could connect an active crossover to the pre outs & then feed left & right bass/mid to one seperate power amp & feed the treble back to the left & right power amp sections in the integrated :eyebrows:

Bingo :)

Techno Commander

01-09-2010, 11:40

That was what I was thinking. :)

audiosanctum

01-09-2010, 12:03

Or as a cheaper alternative you could connect an active crossover to the pre outs & then feed left & right bass/mid to one seperate power amp & feed the treble back to the left & right power amp sections in the integrated :eyebrows:

Bingo :)

I think my idea is better! ;)

Techno Commander

01-09-2010, 14:18

For you maybe. ;)
My wallet prefers the other option.:ner:

audiosanctum

01-09-2010, 14:53

;)

All joking aside, the aim of the game is to get as close to the original sound as possible within in the means available so as long as you use an active crossover that matches well with XTZ electronics you will get a very good sound. We have never used an active crossover with this equipment so we couldn't make any suggestions, unless you have some suggestions Andy...

Reid Malenfant

01-09-2010, 15:00

I'm not Andy :eyebrows: However, this would do the job very nicely indeed (http://www.behringer.com/EN/Products/CX3400.aspx) ;)

I have just had a thought, we know that the integrated has pre outs & a picture of the rear of the power amp shows it to have balanced XLR inputs :) Does the integrated happen to have balanced pre outs & power amp inputs, or is it restricted to single ended phonos?

Either way the above crossover can be used balanced or single ended or a combination of both.

audiosanctum

01-09-2010, 15:19

I have just asked the guys at XTZ to see if they have any recommendations for an active Crossover and they too report the Behringer has proven to intrgrate very well.

Regarding the Integrated, it only has single ended phonos, on the back there are jumpers that allow you to disconnect the power module from the pre-amp. It is where these jumpers are removed that would connect the power amps. I'll try to get you close up so you can see for yourself...

audiosanctum

01-09-2010, 15:31

Rear of A-100D3 showing connections for pre-out and power in...

Reid Malenfant

01-09-2010, 15:36

Aye, standard jumper as seen all over the place ;)

It'd still be fine to run single ended to the Behringer from the pre outs, balanced out from the Behringer to the stereo power amp & single ended back to the power amp input on the A-100D3 integrated :)

Techno Commander

01-09-2010, 18:38

The Behringer is certainly a good XO for the money.

I have a crossover built on the (now defunct) White Noise PCB's. It is set at 50Hz with a 24db roll off. My idea was to use the integrated to power my monitors and the separate power amp to power the JBL subs. :eek:

Reid Malenfant

01-09-2010, 18:49

The Behringer is certainly a good XO for the money.
I agree, which is why i have 2 of the very same sitting here ready to be put into use when i go fully active with my NS1000M based front speakers ;)

You can't really argue with 0.002% distortion, i wonder what the Yamaha passive crossovers produce? :doh: :lol:

Then the crossovers can be tweaked with odd fancy caps etc if needed, i'll also be fitting properly timed delay circuits where they are needed, just a decent op amp & a few resistors & a capacitor & bob's your dads brother :)

They can't be beaten for the money, well i know of no other active crossover that is so flexible & of the same quality fullstop :D

audiosanctum

01-09-2010, 20:18

Aye, standard jumper as seen all over the place ;)

I know it's pretty much standard but i just added the image for any reading the thread who might not be familiar with how it worked.

Reid Malenfant

01-09-2010, 20:29

I know it's pretty much standard but i just added the image for any reading the thread who might not be familiar with how it worked.
Good idea :) I'll pipe down, it's standard because it works as well as you could wish for (so why try to improve it). Ground is taken care of behind the back panel as they are already connected ;)

You are quite correct though, just because i might know this doesn't mean others will ;)

Techno Commander

01-09-2010, 20:37

I just noticed the integrated has sub woofer outputs. What frequency range to these operate over? Is the crossover frequency adjustable?

audiosanctum

01-09-2010, 21:02

The sub output is active up to 300Hz. There is no frequency control as all of XTZ's active subwoofers and subwoofer amps have all the tonal controls so it can all be set from there. Usually most subs have this control anyway so it is usually not needed on the back of the amp itself.

Techno Commander

01-09-2010, 21:12

300Hz is rather high for a sub output and a tone control wouldnt really remove the upper end of the frequency range. I would "suggest" that 100Hz is really the upper end of sub and probably 50Hz would be better. At 300 Hz you are entering into "bass reinforcement" rather than sub.

Usually most subs have this control anyway

I am afraid I would dissagree with this. Subs shouldnt require tone controls, unless they are very small and not capable of producing the required frequencies. Tone controls just provide "more" of what they can produce, which isnt necessarily what you are trying to achieve.

Reid Malenfant

01-09-2010, 21:20

Makes sense to me, i can't think of one active subwoofer that hasn't got a variable crossover frequency :)

Getting things in phase is another matter entirely :eyebrows:

John

01-09-2010, 21:21

Steve
I think he means the sub plate will have the frequency control the bass is allowed to come in at.....which if using active
bass is critical
i agree with Mark phase is importamt
Sorry posted same time as Mark

Techno Commander

01-09-2010, 21:34

Clive

01-09-2010, 21:46

Maybe I should clarify that I was refering to use with passive subs and a separate power amp, as opposed to these little amplified boxes.:)
Therefore you dont have a "tone" control. Whatever they are.;)
Such passive subs tend to be at on the Richer Sounds clearance lines, hardly "proper" subs.

John

01-09-2010, 21:47

I have a friend that uses this http://www.xtz.se/uk/products/electronics/sub-amp-1 with his open bafles sounds pretty good but the room control version would give you even more control

Clive

01-09-2010, 21:52

I have a friend that uses this http://www.xtz.se/uk/products/electronics/sub-amp-1 with his open bafles sounds pretty good but the room control version would give you even more control
Yes, the 2 XTZ Sub Amp 1 DSPs I have are fabulous! Our friend uses a Behringer DEQ2496 for room correction.

Techno Commander

01-09-2010, 21:56

Such passive subs tend to be at on the Richer Sounds clearance lines, hardly "proper" subs.

I beg to differ Sir!!

http://i246.photobucket.com/albums/gg116/sillystuff99/Hi%20Fi/JBL.jpg

Designed for pro cinema use and flatter than Kate Moss down to 20Hz.

:lol::lol:

John

01-09-2010, 21:59

Andy
How do you control the crossover on it and phase

Clive

01-09-2010, 22:06

I beg to differ Sir!!

http://i246.photobucket.com/albums/gg116/sillystuff99/Hi%20Fi/JBL.jpg

Designed for pro cinema use and flatter than Kate Moss down to 20Hz.

:lol::lol:
Then you're talking 5.1 or 7.1 type of use, 2 channel amps for stereo won't have the DSP you need. BTW, the bass unit may be as flat as Kate, what about the room? Unless it's really quite large Kate's flatness will be masked by a totally false and oversized bra.

audiosanctum

01-09-2010, 22:07

Sorry tone control was the wrong word. Frequency control is better. As well as that XTZ active subs have phase control, two eq switches as well as a high pass filter. As for the comment about being little boxes, I'm not sure if you have seen the subs XTZ but they have just brought out a 500W 12" sub with B&O ICE Power which will be reviewed in home cinema choice in September. Having given myself an injury lifting it I wouldn't call them small boxes.

The Sub Amp 1 and Sub Amp DSP are very good units and run very well with Bastanis.

Clive

01-09-2010, 22:10

The Sub Amp 1 and Sub Amp DSP are very good units and run very well with Bastanis.
Indeed they do! It was myself that introduced Robert Bastani to XTZ having discovered the match.

John

01-09-2010, 22:12

Imagine those bass amps run wel with most bass speakers If I had the money I would of got DSP plate amps instead of my BK electronics for my Augiee's

Clive

01-09-2010, 22:15

Imagine those bass amps run wel with most bass speakers If I had the money I would of got DSP plate amps instead of my BK electronics for my Augiee's
Set up is pretty easy too with the Room Analyser but the tones drive the wife and dog mad! :lol:

As with the AP-100, the sub amps are remarkably good value for money.

Techno Commander

01-09-2010, 22:16

Then you're talking 5.1 or 7.1 type of use, 2 channel amps for stereo won't have the DSP you need.

No, I just use pure stereo. It also works superbly well for DVD's too. You dont need DSP if your source, amplification and speakers are responsive at low frequencies. If you use processing, then you are manipulating the original source.

BTW, the bass unit may be as flat as Kate, what about the room? Unless it's really quite large Kate's flatness will be masked by a totally false and oversized bra.

The room is a low cut 30' x 16'.

Techno Commander

01-09-2010, 22:19

Clive

01-09-2010, 22:22

No, I just use pure stereo. It also works superbly well for DVD's too. You dont need DSP if your source, amplification and speakers are responsive at low frequencies. If you use processing, then you are manipulating the original source.

The room is a low cut 30' x 16'.
Your room is of sufficient size to avoid the more typical room modes. Most UK rooms are more like 16' x 12' or 22' x 15' etc. Yes using DSP manipulates the sound (not the source though) but what do room modes do? Much the same thing!

I've measured and listened to deep bass in "typical" UK rooms, room modes abound.....and massively change the sound making bass performance fab on some music and rubbish on the other music.

Techno Commander

01-09-2010, 22:26

Agreed, and yes I should have pointed out about the sound being manipulated. I relaise a rooms accoustics will change the percieved sound. But I assume most poeple do not use DSP on their Hi Fi.

John

01-09-2010, 22:30

Andy
I heard this type of set up that Clive has on a few systems and sounds pretty good
I tried the Ultracurve but did not work for me....just far to complex. Clive has an awesome ssytem and very good gear I spoke to a few people like Marco who heard it and they all say good things I hope one day I can hear it too

John

01-09-2010, 22:32

Yes DSP is still a pretty new concept for most of us

Clive

01-09-2010, 22:32

Agreed, and yes I should have pointed out about the sound being manipulated. I relaise a rooms accoustics will change the percieved sound. But I assume most poeple do not use DSP on their Hi Fi.
Depending on speaker suitability I believe most people NEED DSP on the bass. I use SE valve power above 82Hz but solidstate power with DSP below that. I would HATE DSP in the mid but for the bass it fixes many more problems than it introduces.

Techno Commander

01-09-2010, 23:13

Andy
I heard this type of set up that Clive has on a few systems and sounds pretty good
I dont deny this at all.

Depending on speaker suitability I believe most people NEED DSP on the bass. I use SE valve power above 82Hz but solidstate power with DSP below that. I would HATE DSP in the mid but for the bass it fixes many more problems than it introduces.
A good combination, I like valve "up top" and SS below. As mentioned, I use a lower crossover point, but one which is better suited to the JBL's. I also found a higher frequency sounded too bloated and also started to interfere with the Volts, which are stunningly fast in the 60-100Hz region. I prefer the subs to do sub rather than bass (generally assumed (in the pro world) to be anything above 60Hz).

I do agree that DPS on bass in some instances it required, but that (also) comes from my days of trying to cram 50 Kw into a venue not designed to have 50Kw of audio in it and trying to make it sound as good as possible.

I suppose at the end of the day, it all boils down to what you prefer and what equipment you have and trying to get it to sound the way you like it.:cool:
I will say that for effortless deep and smooth bass, then a 15" driver does take some beating. :):)

John

02-09-2010, 05:31

Yes 15" drivers gives plenty of good bass
Big drivers are also nuce if done well in the mid region e.g some nice duel concenteric drivers=bags of scale and realism

audiosanctum

02-09-2010, 07:55

Set up is pretty easy too with the Room Analyser but the tones drive the wife and dog mad! :lol:

As with the AP-100, the sub amps are remarkably good value for money.

The Room Analyzer does come in very handy for setting a customers room up and at £155.00 the cost totally outweighs the time it saves. Giving you more listening time, that's what i call good result.

I will say that for effortless deep and smooth bass, then a 15" driver does take some beating. :):)

What frequency does your sub go down to, just want to compare it with the XTZ W12.18ICE - http://www.audiosanctum.co.uk/Active-Subwoofers/XTZ-99-W12.18-ICE-Gloss-Black.html

Techno Commander

02-09-2010, 09:34

The JBL's start to roll off at about 30Hz.

audiosanctum

02-09-2010, 22:47

That's not as deep as i was expecting for a driver that large. I think the XTZ 99W12.18ICE would be able to compete with that. XTZ don't publish a freqency range as the lower limit of a sub and any speaker for that matter is dependant on the room, however they do say they have got the sub down to 24Hz in their test room however i don't know how accurate that is and we haven't had them lab tested but i would be interested to know how it compares for your sub. I know that during personnal listening tests these subs go very deep.

Then again a sub that goes too deep can cause more problems than benefits, here is an intersting article XTZ have on their site:

http://www.xtz.se/uk/about-xtz/full-frequency

Techno Commander

02-09-2010, 23:38

That is good for a 12" driver. Your subs do sound good. :)
Here is the JBL frequency response.

http://i246.photobucket.com/albums/gg116/sillystuff99/Hi%20Fi/JBLFreq.jpg

John

03-09-2010, 05:13

Just a personal Observation there is a lot more to bass than how low they go mine only goes down to 26hz but I have so much more bass in the mid bass region helping to capture the texture of acoustic bass the illusiob of realness of drums etc

Clive

03-09-2010, 08:10

Robert Bastani engineers his cabinets to drop off at 30Hz to easy room matching. His logic is that there's little useful bass below 30Hz so why ask for trouble.

audiosanctum

03-09-2010, 09:03

The article that I linked above makes pretty much the same statement, that anything below 30Hz can cause problems in the room. However by having a good driver and well designed cabinet then you have more chance of getting a flat response down to 30Hz, having said that room placement and optimisation also plays an important part which is why the XTZ Room Analyzer is such an invaluable tool.

StanleyB

03-09-2010, 09:15

Robert Bastani engineers his cabinets to drop off at 30Hz to easy room matching. His logic is that there's little useful bass below 30Hz so why ask for trouble.
I would strongly disagree with them. Music styles like reggae, just to name one, rely heavily on musical info below 30Hz. So much so that some reggae DJs hark around bass bins with one or more 18" drive unit in each one, so that they can reproduce those sub 30Hz notes.
One of my test tracks is by Usher, and quite a bit of info in that track can be found below 30Hz. I only became aware of it when I heard that track in my car a few times, and kept wondering why the car interior was rattling like mad every time that track was played. When I checked the track out trough my graphic equalizer display I then realized that there was a whole backing track being played at that low a frequency, but could not be picked up by 'normal' speakers.

Clive

03-09-2010, 09:24

IMusic styles like reggae, just to name one, rely heavily on musical info below 30Hz.
That explains why don't need bass below 30Hz then. :)

Given that you need a 22' 6" room to properly hear even 50Hz (rather than sense / feel), going to the trouble of having bass down to 20Hz in most domestic situations is at best questionable.

StanleyB

03-09-2010, 09:48

I'll leave the theory to others, and concentrate my mind on the experience and quite clearly noticeable end result ;).

audiosanctum

03-09-2010, 09:55

I only became aware of it when I heard that track in my car a few times, and kept wondering why the car interior was rattling like mad every time that track was played.

If that's not an argument for not having subs that go below 30Hz I don't know what is. As soon as you start implementing super low frequencies you start to excite the room in ways that can't be treated acoustically, another word for that is distortion. I don't know about you guys ('n' gals) but i would prefer to have no room interactions in my music reproduction ;)

Clive

03-09-2010, 09:56

I'll leave the theory to others, and concentrate my mind on the experience and quite clearly noticeable end result ;).
Well Stan, you've experienced in your car what happens when you energise it with bass down to 20Hz. My room already rattles with bass down to 30Hz (the door shakes plus a few other rattles), given that I don't listen to reggae I won't worry about the last few Hz and all the associated problems additional bass energy would present.

I used to have subs that went down to 20Hz, I can't say I've missed those few Hz but maybe it's to do with my broad taste in music not being quite broad enough!

Techno Commander

03-09-2010, 11:53

As soon as you start implementing super low frequencies you start to excite the room in ways that can't be treated acoustically

I did manage to excite the front room of a neighbour 2 houses away.
He said things were moving on his mantlepiece. He was quite good about it actually and wanted to see what was causing it. :)

John

03-09-2010, 12:19

I did manage to excite the from room of a neighbour 2 houses away.
He said things were moving on his mantlepiece. He was quite good about it actually and wanted to see what was causing it. :)
Now thats bass:lolsign:

Reid Malenfant

03-09-2010, 17:45

I would strongly disagree with them. Music styles like reggae, just to name one, rely heavily on musical info below 30Hz. So much so that some reggae DJs hark around bass bins with one or more 18" drive unit in each one, so that they can reproduce those sub 30Hz notes.
One of my test tracks is by Usher, and quite a bit of info in that track can be found below 30Hz. I only became aware of it when I heard that track in my car a few times, and kept wondering why the car interior was rattling like mad every time that track was played. When I checked the track out trough my graphic equalizer display I then realized that there was a whole backing track being played at that low a frequency, but could not be picked up by 'normal' speakers.
I'm in total agreement here. I listen to a lot of ambient music & alsorts generally, i have quite a few CDs with strong bass content down to 15Hz (some lower still) & it makes itself more than known when it's there :)

That explains why don't need bass below 30Hz then. :)

Given that you need a 22' 6" room to properly hear even 50Hz (rather than sense / feel), going to the trouble of having bass down to 20Hz in most domestic situations is at best questionable.
Actually what you need to think of is if you stick your head inside a sealed box are you only going to be able to hear bass down to the frequency that can fit into the longest box dimension? :scratch:

No, you'll hear it a lot lower :eyebrows: You just won't get any standing wave reinforcement ;) Bass actually appears to get cleaner once you drop below the theoretical lowest room frequency i find :)

I'll leave the theory to others, and concentrate my mind on the experience and quite clearly noticeable end result ;).
Likewise :)

E2A:- If the lowest frequency reproduced in a room is down to room size then how come headphones can reproduce bass? There can't be more than 2.5" between the diaphram & the ear diaphram ;)

Ali Tait

03-09-2010, 18:12

I thought cd was limited to 20Hz? :scratch:

Reid Malenfant

03-09-2010, 18:16

I thought cd was limited to 20Hz? :scratch:
I think you'll find the limit is 1Hz if not nearly DC ;) Why should there be a low frequency limit? I can understand 22.1Khz top end with 44.2Khz red book standard, no limit on the bottom though :)

Ali Tait

03-09-2010, 18:36

Ah it's just the top end then?

Clive

03-09-2010, 18:37

No, you'll hear it a lot lower :eyebrows: You just won't get any standing wave reinforcement ;) Bass actually appears to get cleaner once you drop below the theoretical lowest room frequency i find :)

E2A:- If the lowest frequency reproduced in a room is down to room size then how come headphones can reproduce bass? There can't be more than 2.5" between the diaphram & the ear diaphram ;)
I suspect bass is cleaner below the theoretical lowest room frequency because you're hearing a truncated part of the notes being played. I agree that a lack of standing waves is a contributory factor two.

As mentioned by Techno Commander real bass travels long distances and IME when you don't get the full effect in the listening room (due to room dimensions) if you walk around the house you'll find the full bass wave somewhere. This is a very common experience.

Deep bass can be heard in the right setting but as I hinted at earlier it's also about feeling and sensing it. I don't believe it's all about hearing it.

Also, as mentioned by Ali, I too thought there was something in the redbook spec that limited bass to 20Hz, if there ever was maybe it's ignored, for sure test CDs go lower.

Ali Tait

03-09-2010, 18:40

Found this-

http://en.wikipedia.org/wiki/Nyquist_frequency

Reid Malenfant

03-09-2010, 18:42

:exactly: Take it from me Ali, i could show you 15Hz waveforms from red book CD on an oscilloscope, that would produce quite a bit of volume. The same volume level as mid frequencies would be at on the same recording ;) If the speakers were capable then you'd know about it :)

Ali Tait

03-09-2010, 18:47

18-inch drivers anyone?? :lol:

Techno Commander

03-09-2010, 18:50

Precision Devices (http://www.precision-devices.com/showdetails.asp?id=17) do a rather good 24" driver. :)

Reid Malenfant

03-09-2010, 18:54

I suspect bass is cleaner below the theoretical lowest room frequency because you're hearing a truncated part of the notes being played. I agree that a lack of standing waves is a contributory factor two.

As mentioned by Techno Commander real bass travels long distances and IME when you don't get the full effect in the listening room (due to room dimensions) if you walk around the house you'll find the full bass wave somewhere. This is a very common experience.

Deep bass can be heard in the right setting but as I hinted at earlier it's also about feeling and sensing it. I don't believe it's all about hearing it.
As i say then, how do headphones reproduce deep bass with a 2.5" path between driver & ear diaphram?

It's about pressure at such low frequencies & speakers can be good for changing atmospheric pressure, after all it's what you are hearing. Yes i can walk about the house & find a place where such & such gives an optimum response say at 25Hz or lower. This won't stop you feeling it in the listening room, you can't fail to as any volume level at 15Hz that can be heard is near on 95Db & you'll feel it to.

Honestly, i ask you to consider how headphones reproduce deep bass with a 2.5" path, a room is much bigger & with no possibility of standing waves because it's too small i'd suggest pressure will more than make it's mark in the hearing department & in your chest as it'll shake & rattle you about ;)

Ali Tait

03-09-2010, 18:55

Aye,but then you've got to fit the cabinet into your listening space! And you better live a looong way away from other folk...

Reid Malenfant

03-09-2010, 18:58

Aye,but then you've got to fit the cabinet into your listening space! And you better live a looong way away from other folk...
Not really. Only if you want to go to nuts volume levels. Just because a speaker might be capable of reproducing 15Hz doesn't mean it can do it a stupid volumes.

A bookshelf speaker isn't going to annoy the neighbours except in the midrange.

Ali Tait

03-09-2010, 19:01

Clive

03-09-2010, 19:08

I take your point about headphones but you seem to agree that the main listening room may not be the place for optimal bass, this can occur elsewhere. I fully agree that we can feel the pressure in even in a small listening room but I question whether we hear the full effect and quality of the notes, yes we hear something but is it all there? It seems not as the bass can be better elsewhere in the house. This is not an all or nothing scenario.

Reid Malenfant

03-09-2010, 19:19

Yes,but the point is that bass frequencies travel a long way.Whales can communicate all the way across the planet.You can't tell me your neighbour isn't going to notice your new speakers using 18 inch bass drivers!
Ali, i have 8 x 15" bass drivers with 2 x 15" in each enclosure & each enclosure is 440L ;) Each house wall is solid 2 thickness brick & the bay window is filled in with these present subs thus giving me my low ambient light AV room & deep bass. It can be heard from the street when it's turned up a tad. No doubt heard from further afield if cranked, but even a moderate listening level is enough, take it from me :eyebrows: I'll get a pic up when i can..

Those 4 x 440L enclosures will be replaced & out performed by a couple that will total less than 300L for them both.

Yes, things flex that normally wouldn't :lol: You don't get it all unless you get it all though...

Never had a complaint from the neighbours :) Obviously i take it easy :lolsign:

Techno Commander

03-09-2010, 19:41

Reading these posts about bass travel reminds me of when we were working at the second Tribal Gathering at Luton some years ago. We had traveled up in an ex army radio comms van. Combined with the 7 of us, a couple of 4Kw xenon searchlights and 16 cases of beer, I reckon the all up weight was around 5 tons.

We arrived on site the day before the event started and after a good nights drinking, we finally crashed out in the back of the wagon around 4AM. Unfortunately, we were rudely awoken at around 9.30 when they decided to sound check the PA in the marquee we were parked near to. I guess we were approx 50 yards behind where the PA was stacked and thusly were not "in the line of fire".

Apart from the noise, there was sufficient air pressure to cause the truck to physically bounce on its springs to the beat of the music. We could also hear the tinnies rattling in their cardboard cases :)

Further investigation revealed an Electrovoice MT4 (http://www.pa-anlagen.ch/Manuals/Electro_Voice/Speakers/EDS/MTL-4B%20EDS.pdf) rig within the tent, with 24 of these bad boys a side.

http://www.solarisnetwork.com/product_listings/13069/71840455_xlarge.jpg

Thats 192 18" drivers with about 80Kw of muscle behind them. To this day, I have never heard or experienced bass like it. Hard, fast, totally in control, but enough power to make your rib cage and dangly bits resonate.:eek:

Techno Commander

03-09-2010, 19:45

Ooh, i've hit 500 posts. :)

Reid Malenfant

03-09-2010, 19:51

Flamin hell Andy :eek: That's mad, well madder than me at any rate by a long chalk :eyebrows:

Here is my present bass setup, something tells me this thread has drifted off topic, my bad to :doh:

Just so Ali believes me... 4 x 440L with 8 x 15", one is hiding behind the chair ;) Bay window well & truly filled..

Off to discover the undiscovered :)

http://i939.photobucket.com/albums/ad240/speakermark/present%20subs/Picture001-1.jpg

Techno Commander

03-09-2010, 19:58

Very nice.

I should also apologise to the OP for thread drift.

But it is keeping his amplifier name at the top of the threads list.:)

Clive

03-09-2010, 20:13

I see how close the chair is.....now I know what you mean by headphones! When the drivers move backwards doesn't the air get sucked out of your lungs?

John

03-09-2010, 20:26

Alex_UK

03-09-2010, 21:50

Mark - you really are a mentalist, there is just no other description! :lol: I think I remember reading elsewhere that you're single - are the speakers because you're single or are you single because of the speakers? ;) - my wife is very accepting of my afliction but I think even she would draw the line at living inside Wembley Stadium! :)

(All meant in the nicest possible way, I hasten to add! ;))

Ali Tait

04-09-2010, 07:38

Yep,definately mad as a box of frogs.:stalks:

Clive

04-09-2010, 15:30

Following up on the discussion on room dimensions and bass wavelength. I've been researching this. There are various views but the main one seems to be that you need a room dimension 1/4 the frequency wavelength for "good" bass response, this can of course be a diagonal. So you get down to 14Hz with a diagonal of just 20ft (pretty easy).

Re headphones, it seems that what low frequencies can be heard are not regarded as "good" though I'm sure head-fi guys will disagree. For sure it's different as via headphones such frequencies are only sensed by the ears, not the whole body.

audiosanctum

05-09-2010, 10:51

I should also apologise to the OP for thread drift.

But it is keeping his amplifier name at the top of the threads list.:)

Who wants to buy one then :whistle:

http://www.audiosanctum.co.uk/Power-Amplifiers.html

John

05-09-2010, 12:37

Just let us know if you wish to move the thread drift

audiosanctum

05-09-2010, 16:24

I was hoping the thread above might do that!

We now have every colour option in stock as opposed to just the Silver/Black two tone version.

Butuz

16-02-2011, 20:37

Pity this thread has been dragged so off topic. Entertaining nonetheless!!!

So has anyone purchased one of these amps in the last 6 months??? Any more views???

Butuz

Reid Malenfant

16-02-2011, 20:43

Pity this thread has been dragged so off topic. Entertaining nonetheless!!!

So has anyone purchased one of these amps in the last 6 months??? Any more views???

Butuz
I'm sure at least one member of this forum has purchased the integrated amp version of the very same, maybe a couple. I think Effem has & i know at least one other has as he sold me his Beresford Caiman (which i sold on at the same price) as he no longer needed it, the integrated has a built in DAC :)

I can't remember who i bought the DAC off of though :doh:

They are both very happy apparently :cool:

audiosanctum

16-02-2011, 20:55

We have plenty of happy customers, if you're not sure whether its for you either try one on 2 week demo or buy one with a 30 day money back guarantee.

http://www.audiosanctum.co.uk/demo-facility.html

Effem

16-02-2011, 20:59

I have the integrated and it is a real doooozy :eyebrows:

I took it round to a friend's house a few days ago and it certainly made him VERY disgruntled with the 5 figure amp he has now. Had to lever his fingers off it when it was time to go home. Offered money, offered his kidney, offered his conjugal rights for the next 6 months, so I told him to stop crying, get a grip and go buy an XTZ Desire forthwith at the ludicrously cheap price being asked for it :eyebrows:

Incidentally, I did split the pre and power sections of the XTZ out of curiosity to connect a pre amp and the power amp section is a cracker.

audiosanctum

16-02-2011, 21:03

I didn't pay him i promise ;-)

Effem

16-02-2011, 21:11

I didn't pay him i promise ;-)

That's not what you said earlier :scratch:

In that case it is CRAP

:lies:

Nah, only kidding :lolsign:

I can honestly say it is the best amp I have owned. It comfortably out-performed an expensive valve amp and another well known class A amp with ease and when you also consider the price tag includes a remote, MM & MC phono stage, flexibility of inputs AND a really good quality DAC into the package, it really is a true "no brainer" and I have no hesitation whatsoever in urging you to put it on your next upgrade shortlist - and save a good few quid on what you WOULD have spent.

zygote23

16-02-2011, 21:44

Effem

16-02-2011, 22:41

Hmmmm......I have itches!

Sugden a21se or XTZ? Difficult to demo either over here.
I played with a Storm Audio amp a few weeks ago and it's got me wanting more power than my current amp.

Having heard both amps Steve my money would be on the XTZ and that is why I now own an XTZ and not a a21se :eyebrows: Mind you, I do like a very clean very well controlled sound, even when the music gets very complex. The XTZ untangles everything and stays crisp whatever you throw at it, so each and every instrument and vocals in the mix stays firmly placed where they should be without any muddling or smearing. Not many amps this side of £4k can manage that, least of all the MF Trivista 300 I had a few years ago.

Welder

17-02-2011, 00:51

Hmm, I must admit to being interested in hearing the integrated.
So Frank, is it the integrated you have?

Effem

17-02-2011, 08:56

Hmm, I must admit to being interested in hearing the integrated.
So Frank, is it the integrated you have?

Yes it is the integrated I have.

You can have one on home dem, they will probably be demonstrated at the Brissol hi-fi show, or come down to my bakeoff next month :-)

http://www.xtz.se/custom/view_images/image.php?IMAGE_ID=20090520111254-01.jpg&size=800&typ=1

http://www.xtz.se/custom/view_images/image.php?IMAGE_ID=20090520111323-01.jpg-02.jpg&size=800&typ=1

Just look at the amount of inputs including the DAC which has 1 optical and 4 co-axial sockets.

Before you contemplate having a play with one, please be aware it is a pretty big beast, so check your rack dimensions. Size (HxWxD): 150 x 435 x 410 mm/460mm incl volume knob and speaker terminals (HxWxD)

I have never been keen on black but, this looks "right" to me because the colour makes it look smaller than it is