Demian, it is confusing. Speakers are very efficient low pass filters. And I believe our ears too. What can be the influence of high order harmonics produced by our amplifiers witch are out of the speaker range ?
Having just done a 150 mile round trip had a time to think about this and can only think of one case where the centre diff would help, which is if you hit a puddle under braking so had an excess of grip on the opposing rear. For the case of Mr AMG on a dry road there would have been a lot of front weight transfer and a likelyhood of a rear locking. In this case the fronts would have been unlikely to have the excess.
To put this in to context, he had overtaken about 10 cars, starting from behind me and was doing silly speed (was still at full throttle almost until he hit the anchors. I suspect the electronics helped him a lot.
B****dy nice sound on full bore I have to say
To put this in to context, he had overtaken about 10 cars, starting from behind me and was doing silly speed (was still at full throttle almost until he hit the anchors. I suspect the electronics helped him a lot.
B****dy nice sound on full bore I have to say
I spent an evening listening to my friends system. She was for years at the BBC as a sound engineer . She has a degree in music. I heard for the first time in my life what I think are called LS5/9. The first impression is of a slightly underdamped bass and a very BBC saucer shaped recessed midband ( crossover phase shift compromise at circa 3 kHz I would guess ). Then 20 seconds into the listening it became pure magic. They are so delicate. The amps were some Graham Slee 25 watt jobs standing in for the broken Krell.The speaker is as near to the actual 5/9 as is possible I am told. The Volt treble unit used in these I suspect would be better. The build quality just fantastic. What a pleasure. For all that not my exact cup of tea.
Graham Audio - British manufacturers of high quality loudspeaker systems
From the silly to the sublime. I had a trip in the Mercedes SLK CDi. 0 to 60 MPH 6.7 S 151 MPH and realistic 45 miles per UK gallon ( 37 US 6.3L/100 kM ). Book figures 56 UK and realistic 37 UK fast driving ( Autobahn ). For all that my lady friend Martina's 3.2 L Jag XJ6 suits me better. She says the 3.2 is a fuel miser, she can get 28 UK which is not easy to believe as my Ford Focus Ghia was not as good ( lovely car ). Martina rebuilt the engine! One near perfect XJ she bought for the engine cost about $1100. She keeps telling me she will do up one for me. I think I should give in and say yes. Maybe it's my Garrard 401 Naim Aro she is swapping? It went on holiday to Germany and refuses to come home. I have another with Schroeder coming alive. It will possibly use a DL110. The Schroeder defeats the idea that vinyl sound good due to arm resonance. OK it has some. Not the nasty ping pong metalic stuff that people suspect makes vinyl sound more interesting than CD. They think the usual LP sound is " better " than the mastertape. What planet are they from? They will use CD as they know LP is corrupted.
To listen to the LS5/9 a Krell CD player used. Have to say it was very good. Also some Linn 24 bit material that sounded like a singer on a cruise ship. The Townsend Rock alas was not available. For Ex BBC she has Audiophile tastes. I am going to make her some ultra cheap cables to show her it isn't money when them. What she uses fits the same style. I prefer very cheap silver plated either 0.6 or 0.25 mm wire in PTFE. My system has more bass than is typical because it has power. 0.6 mm wire will do well for that.
An interesting observation from her. A trial was down in BBC blind listening style. 24 bit, 16 bit and MP3. Mostly all were well liked with no simple prefence. 16 bit did best, then MP3 and finally 24 bit. I can understand that. For me 24 bit is stunning, but perhaps that is people working harder to make sure it shines. I like MP3 as it is so much better than one would think. This lady never tells people she only uses CD to review products. Simple reason being is never changes. How many times has a PU had to be changed when LP after too much wine? The Rock is used after the test. I agree with this.
Graham Audio - British manufacturers of high quality loudspeaker systems
From the silly to the sublime. I had a trip in the Mercedes SLK CDi. 0 to 60 MPH 6.7 S 151 MPH and realistic 45 miles per UK gallon ( 37 US 6.3L/100 kM ). Book figures 56 UK and realistic 37 UK fast driving ( Autobahn ). For all that my lady friend Martina's 3.2 L Jag XJ6 suits me better. She says the 3.2 is a fuel miser, she can get 28 UK which is not easy to believe as my Ford Focus Ghia was not as good ( lovely car ). Martina rebuilt the engine! One near perfect XJ she bought for the engine cost about $1100. She keeps telling me she will do up one for me. I think I should give in and say yes. Maybe it's my Garrard 401 Naim Aro she is swapping? It went on holiday to Germany and refuses to come home. I have another with Schroeder coming alive. It will possibly use a DL110. The Schroeder defeats the idea that vinyl sound good due to arm resonance. OK it has some. Not the nasty ping pong metalic stuff that people suspect makes vinyl sound more interesting than CD. They think the usual LP sound is " better " than the mastertape. What planet are they from? They will use CD as they know LP is corrupted.
To listen to the LS5/9 a Krell CD player used. Have to say it was very good. Also some Linn 24 bit material that sounded like a singer on a cruise ship. The Townsend Rock alas was not available. For Ex BBC she has Audiophile tastes. I am going to make her some ultra cheap cables to show her it isn't money when them. What she uses fits the same style. I prefer very cheap silver plated either 0.6 or 0.25 mm wire in PTFE. My system has more bass than is typical because it has power. 0.6 mm wire will do well for that.
An interesting observation from her. A trial was down in BBC blind listening style. 24 bit, 16 bit and MP3. Mostly all were well liked with no simple prefence. 16 bit did best, then MP3 and finally 24 bit. I can understand that. For me 24 bit is stunning, but perhaps that is people working harder to make sure it shines. I like MP3 as it is so much better than one would think. This lady never tells people she only uses CD to review products. Simple reason being is never changes. How many times has a PU had to be changed when LP after too much wine? The Rock is used after the test. I agree with this.
It was one thing to do virtually any mechanical repair but then along came software control! Matters are further complicated as designs allow more and more to be shoehorned into less and less space - often necessitating special tools available only to registered agents. Other than changing filters, oils etc there is little left which the average (old fashioned) 'enthusiast' can do. The very last big job I took on was rebuilding a 3500 Maserati engine.....that was in the early 70s...45 years ago. Since then the heads on a v8 Ford (to have a small face grind). I'm hardly prepared these days to open the bonnet. (Audi Quattro T 3L Avant, which is also the only automatic gear change car I've ever owned)
Beyond the injection system I don't even know what half of the electronic devices are supposed to do, let alone adjust them. Any non-trained guy/girl who can be totally familiar with all of this stuff and with standard tools work on any aspect has my fullest admiration.
If you ever meet her she is a lovely lady. I think I caused this to happen. She said people always took her to be a sales person. She was Thorens parts lady. She knew not only the parts, but also how they work. She wanted a job title. The first I would love to say, but I suspect the moderator would jump on me hard. We settled on Devellopement Engineer. I said she could put it on her business cards as long as it was true. I said from that point on I would give her ideas and she would try them. The rest is history although it took a bit longer this way. I have no idea how she gets to the answers she does. It's a logic that isn't the usual. The results speak for themseleves. To say it was easy would be a lie. I always suspect she doesn't listen to me, but knows what I want.
I had a look at these. They might adapt to hi fi by EQ. Less power and more low end. A pair might be an easy way to get deep bass. Underdriven cheap pro gear can work. Any thoughts? The idea is to trade 16dB of level for more sub bass.These almost look to be a serrious device. Hopefully Dan knows them? 15 Hz - 6dB would suit well. £300 inc tax and shipping the pair.
Vexus SWP15 Pro 15" Powered Active DJ Subwoofer Bass Speaker 800W
Vexus SWP15 Pro 15" Powered Active DJ Subwoofer Bass Speaker 800W
A quick look at the box and the specs suggest getting low bass from it will be difficult. It lists 40 Hz as a LF limit. My guess is that it has a 50 Hz resonance in the cabinet and 12 dB if sealed or 18 dB if ported rolloff below resonance. Getting bass extension that sounds good this way is not easy. For this to work you should have a resonance of around 30 Hz to get extension. 18 dB of boost to get the LF extension usually means lots of unintended clipping.
That Vexus looks like it has a slot port at the bottom of the cabinet.
They state it has a low pass filter that is adjustable from 40Hz to 250Hz. not
I also don't understand
But the over-riding attraction is the extremely good value for money, even if it needs a few tweaks to get the best from it.
They state it has a low pass filter that is adjustable from 40Hz to 250Hz. not
They also state resonance free. But I have no clue on how they have achieved that.
I also don't understand
how does an active speaker that has an unknown input impedance use a 1W signal level?
But the over-riding attraction is the extremely good value for money, even if it needs a few tweaks to get the best from it.
Never met them.
These kinds of boxes can be great in their intended application as subs for modern/rock stuff, but they ain't intended for really LF stuff.....most 'radio friendly/top 40' or live stage stuff doesn't have any serious very LF/ULF bass.
That said, the amp modules and enclosures/drivers would be ripe for experimenting/improvements.
For the price, being able to stereo augment the bottom end is gold.
I can't wait to hear accounts of your experimentation.....zobels, constant current mode, variable phase, variable/contoured monoing/summing........
Dan.
Last edited:
A subwoofer is most effective when it is carefully designed for the actual application it is to be used for. This device is made for a purpose which may align with some people's vision of an audio system, IOW high efficiency at a large cost in bass extension.
However, most audiophiles seem to be interested in modest efficiency and improved bass extension.
The design of a speaker system for either purpose diverges early on in the project. There are subwoofer drivers that have different design features that make them more suitable for one purpose or the other.
Equalizing a speaker system with limited bass extension so that it has significantly greater bass extension has definite limits. Again, a bass speaker driver is designed along two different, mutually exclusive paths depending on the application.
The critical parameters are diaphragm size, Xmax, and the efficiency of the motor, that is the voice coil and the magnet. Two completely different sets of choices are generally made depending on whether the application is sound reinforcement or for a musical instrument, or if the application is high fidelity audio. Either may incorporate some equalization, but even that differs significantly depending on the application.
Well done everyone. It's too much money to risk on a whim. I was also baffled if you would allow by the 116 dB/W.
I am not a poor man and could risk a few pounds. If I win then I pass on the winning idea. The idea was to hope at low level the although obvious problems might give me 100 dB output I don't have between 15 and 80 Hz. I realise that's a wish list that seldom can be real. The analogy we might use is our 440 inch V8 that will surprise us all. Somehow when that big hard things can be made easy.
The size might be the reason I give this up, I have the room but do my eyes want to see them. The port I dislike if true. It could be resistively loaded as an idea. Drinking straws if Proac and ventillation grill and cloth if Dynaco.
I took a gamble on a spare part for a speaker like this at 15 inch and hit the jackpot. It was dirt cheap.
My BBC friend has built a resistive port for her BC1's and says better than her LS5/9. I wouldn't ask her to share more as I know that's out of order. People can do their own. Having played with BC1's recently I can imagine it works. When BC1 hits the port frequency the lower frequency music vanishes. Not sure any port speaker I heard before is so dramatic. It isn't very obvious without better speakers to show it up. I guess the truth the graphs always told made very real.
One problem I will have is time delay. This is bad enough when normal speakers. A digital delay I can borrow anytime I like and it will be of a very high grade. That's fine up to a point, were it the subs I delayed I wouldn't give it a second thought. Were it just for CD the same answer. To use digital delay for my low distortion minimalist phono circuit is not where I want to go. To put the subs side by side where I listen might be just about be OK. I have 2.5 metres to the speakers. If this is wrong dynamics are totally lost. Pro-audio guys know this.
Some may remember many years ago Dejan ( DVV ) said me saying twin subs are needed made him take note. I said it makes life easier and could be better. My point being ideal speakers have the range anyway and we never question that. To be honest I don't know what these ideal speakers might be if given a name. I found single subs colour the sound. Some say it's my love of LP that makes me say that. Not really as CD seems no different. One single sub makes me hear a sound approaching mono. Like we have 10 dB sepparation. Doubtless only I hear this. Also singers become larger than they were.
I have a good audio memory. I can still hear that sound of the JR sub years ago. I can hear the diffuse quality that resembled real life lost. As the recording is summed below 100 Hz when LP it may well be as some say out of phase distortions in LP's is what we hear. I swear I hear the same on CD although perhaps it matters less to me. That's not me saying it's better. Just saying given CD with or without deep bass I prefer with. Saying that, at a friends house we only got through 10 minutes of CD before I asked him how his health was that day when trying his sub. His health rivals the tales of Oddeseus.
A point of related interest. Many years ago a young friend wanted an audio project. I suggested a Hafler 4 channel decoder that looks so simple. Were it not Hafler it might have been thought a lie. A debate in the Hi fi News included many serrious matamaticians. They said the Hafler circuit could decode Quadraphonic LP's almost to the same standard as an expensive decoder. What this hinged upon was the usual standards war. Hafler was the better compromise and could be built without any technical knowledge except following a wiring diagram something like a speaker switching box.
Adam went away and that was it I thought. One day he asked to pull apart my listening room and gave me a demo. I had 4 Mission 760i I think to keep all speakers the same and low cost. Adam brought his state of the art Dolby box. We played Hafler verese Dolby and the Hafler was vastly better. It seems enough information was contained in the so called front channels to make it seem real. The sound was less processed which I guess is obvious. The stunning test was LP. Suddenly harshness and noise was transformed over if only just two speakers. OK noise was still there. The difference was it was not as important. Like it was outside and not inside the room. When the Dolby was asked to do a synthetic maxtix sound it was the other way. It made it more inside the room. As hard as it was to understand the Dolby screwed it up.
Soon after this Adam bought a company that re-chiped car fuel systems. Taught himself how it worked and forgot audio. Briefly he showed all the signs of wanting to be an audio engineer.
Adam went away and that was it I thought. One day he asked to pull apart my listening room and gave me a demo. I had 4 Mission 760i I think to keep all speakers the same and low cost. Adam brought his state of the art Dolby box. We played Hafler verese Dolby and the Hafler was vastly better. It seems enough information was contained in the so called front channels to make it seem real. The sound was less processed which I guess is obvious. The stunning test was LP. Suddenly harshness and noise was transformed over if only just two speakers. OK noise was still there. The difference was it was not as important. Like it was outside and not inside the room. When the Dolby was asked to do a synthetic maxtix sound it was the other way. It made it more inside the room. As hard as it was to understand the Dolby screwed it up.
Soon after this Adam bought a company that re-chiped car fuel systems. Taught himself how it worked and forgot audio. Briefly he showed all the signs of wanting to be an audio engineer.
Last edited:
My friend also called Nigel built his subs with a horn and a solonoid. I never saw them. He was the one who introduced me to the delay time needed. His were large due to the solonoid mass. He wasn't put off and made it work. He asked me to guess what happened. I said the volume became vast even though unchanged. The smile on his face as he said yes. He also said it made you want to dance.
Nigel C left Pro-audio. What killed his business was inventing. If he had bought himself a humble Turbosound set up he would have made money. I learnt a lot of my worse thoughts off of the other Nigel. Such a shame he gave up. His best business was with African music, they loved him and thought him a master. I did also.
Nigel C left Pro-audio. What killed his business was inventing. If he had bought himself a humble Turbosound set up he would have made money. I learnt a lot of my worse thoughts off of the other Nigel. Such a shame he gave up. His best business was with African music, they loved him and thought him a master. I did also.
Anyone want to view this youtube ? I wouldn't blame you if you didn't. I like Bill Lowe, but not this presentation of whoever this is. I started at 4 and now 60 if his yardstick matters.
I was highly upset to hear Tesla being said to be not good enough for today. Apart from the almighty I have no other I admire as much as Tesla. I actually found 40 Hz to be interesting if I would change anything.
https://www.youtube.com/watch?v=ITkuBgFtTjs
I rebuilt some Celestion DL4 today. Doped the cones and metal tweeters. The later idea taken from a design I repaired and spotted. A metal cone sounding good! My my LS3/5A these might be better in some ways.
I was highly upset to hear Tesla being said to be not good enough for today. Apart from the almighty I have no other I admire as much as Tesla. I actually found 40 Hz to be interesting if I would change anything.
https://www.youtube.com/watch?v=ITkuBgFtTjs
I rebuilt some Celestion DL4 today. Doped the cones and metal tweeters. The later idea taken from a design I repaired and spotted. A metal cone sounding good! My my LS3/5A these might be better in some ways.
- Status
- Not open for further replies.