Audio Output Distortion

Audio Output Distortion 

I am a relative noob to the world of pro audio equipment. I have made many speakers over the years, and they work well, but I have recently come across a strange problem with recent purchase and here I present my research notes and links to the various resources.

The Problem 

I have recently acquired an akai rhythm wolf drum machine,  and the main signal output is showing some strange behavior.

When I'm using a high quality pair of headphones such as Sennheiser HD280 Pro the sound quality from the rhythmolf is excellent. I am particularly interested in The Sound of the bass drum here.

So the bass drum or kick drum gives out very delicious low rich bass when using the headphones which is what I like the here . . .! . . . however when I plug the output into a speaker which I normally use for listening to music the bass drum sounds very thin and the hardly any bass is produced.

If you turn the volume on the kick drum too far then it starts to distort in a crackly sort of way so I'm trying to figure out what's going on there why am I getting thin bass when I'm using a speaker and what am I getting why am I getting good base when I'm using headphones.

I should say this behaviour repeats on 3 types of speaker:

• Small Sony Bluetooth Speaker - Works fine with synth, and other drum machines. 
• Soundboks 2 - Very heavy duty unit, works fine with synth, and other drum machines. 
• Home Made Speakers - 2 Large Active Speaker containing 4 x TPA Amplifiers and 4 x 10" subwoofers. Which when playing music from spotify are extremely loud. 

The Fix = Mix . . er

I contacted AKAI Support there response was:

"The problem with the weak, distorted kick drum might be expected as it is not recommended to directly connect a speaker to the rhythm wolf Main Out. Instead, use a standard 1/4" (6.35mm) TRS cable to connect this line-level output to the input of an audio interface, mixer, amplifier system, etc. Additionally, stereo headphones can be connected to this output. If the Synth Out is left unconnected, the Main Out will include the drum and bass synth voices. However, if a cable is connected to the Synth Out, the Main Out will include the drum voices only."

I also contacted the chap I bought it from:

Me: "Hey mate did you always run this through a mixer"

Seller: "Hi yes I did run it through a mixer. It has some serious sub on the unit, I'd check the EQ settings on your speaker and set it to "flat" is possible." 

Noob Fault Finding 

Below are musing on why this is happening. 

First Reaction 

An initial experiment I tried was to route the output to a headphone amplifier and then the headphone amplifier to the speaker. This didn't work. Very thin "sniky" bass drum. 

Research 

So something coming out of the Rhythm Wolf is the wrong level for the 3 speakers I have tried out. The output has too much power, or not enough, or the receiving speakers are expect something within a certain range and that isn't happening. So lets figure this out:

Impedance 

My HD280 Pros are 64 Ohms. 

"Most headphones have an impedance that is typically between 8-600 ohms."

https://www.headphonezone.in/blogs/audiophile-101/understanding-impedance 

"All these factors, make us arrive at something important known as Impedance Matching."

A guitar amplifier is high impedance. . . I plugged in the drum machine to a Yamaha GA15 and I get the same behaviour as I do with speakers, the kick drum sounds very very weak. I can turn up the snare drum and other outputs and they are very loud and distortion free. 

"An impedance mismatch in a circuit or along a transmission line will produce a reflection back to the source of the signal. When a signal reflects, the power transferred downstream towards a load is reduced. Impedance matching provides a dual role of enabling power transfer into a load by suppressing reflections."

https://resources.system-analysis.cadence.com/blog/msa2021-how-signal-reflection-and-impedance-mismatch-are-related

So it sounds like it could be impedance. But my guitar amp experiment doesn't work. It need to be low to high. 

https://youtu.be/WMg15uF2SAo

Voltage 

Is it voltage of the output, I have read 2V is typical. Is it more than that or less?

Power Supply

I have read that using a different power supply for the Rhythm Wolf can fix a problem with distorted outputs. However, I have switched the adaptor and it didn't;'t work. THe manual says 12V 2A Supply which is reasonably beefy. 

It was supplied with a 12v 600ma, but swapping that to a 12v 2a has not helped. 

More amps? Probably won't help. 

Distortion  Notes 

"Possible causes of audio distortion problems may be: Wrong input level to the amplifier. Amplifier gain is set too low or high. Not enough amplifier power."

https://blog.miscospeakers.com/preventing-speaker-distortion-increasing-listenability#:~:text=Possible%20causes%20of%20audio%20distortion,Not%20enough%20amplifier%20power

Flood Risk Assessment London 

Is UK2 a Good Hosting Company in 2024?

UK2 is a web hosting provider. They also sell domains and provide more complicated cloud computing services such as VPS etc. But is UK2 a Good Hosting Company in 2024? No they are not. 

Rewind . . . . 

If someone had asked me "Is UK2 a Good Hosting Company" around 2 years ago I would have rated them excellent. Apart from a few domains registered with Google Domains, and a couple of older sties hosted on Firebase, I had all my websites with UK2. Probs about 10 in total. 

The reason I was so please with UK2 up until a couple of years ago was that I thought they really understood what the customer wants, i.e reliability and expandability. 

 All was well. I had used UK2 for over 10 years, and it had been super reliable. THey obviously had it all figured out. . . .

UK2 . . . . THG 

So around Jan - February 2024 I noticed the UK2 website was rebranded UK2 THG. No big deal I though companies get bought out all the time. 

But around April 2024 one day all my websites went down, and when I contacted support no body answered the ticket, I waited for 36 hours before I got a reply. I'm not really sure how much I lost in leads, on a pro-rata basis it would be about £2000. 

Here is the review I left on UK2 THG Google Maps Listing 

So I will write the details of what happened (and reduce to 1 star - facepalm):

a- I had to wait 36 hours for a support ticket to be answered, I missed out on a day and a half of leads, goodness knows how many opportunities lost,

b - turns out this was because you changed from working system (CPanel) to StackCP

c - You didn't update nameservers automatically

d - You didn't even email me to say you were doing this!

e - After 24 hours of waiting I had to make a move and so very laboriously I have had to move my websites and domains to other servers.

Whatever possessed you to mess with a working system, not tell anyone about it, whilst blanking me on support for 36 hours. You couldn't make this stuff up.

Stack CP

But Stack CP is OK right?

No no no, its not OK. I spent 2 hours today trying to hook up filezilla, to FTP. I have to log in to Stack CP to unlock, and then the FTP client won't connect. I have tried dozens of different configs. No joy. 

Well perhaps I can upload the files using file manger. No. In trying to upload about 8 files to the required director it results in files disappearing instead of being overwritten, and not all of them are over written. Its a right mess. 

So from my limited experience Stack CP os absolute garbage. I wonder how much money they saved by switching.

Conclusion 

I would have been a customer for life with UK2, I had no reason to change. I don't pay a lot say £240 a year of something like that. But I would have paid it for years to come. . . happily for a reliable service. 

I wonder how many customers they lost. 

FYI I went to Hostinger they do a specific Control Panel hosting package. It costs about a quarter of the price and works just as well. 

If only I could get back the 50 hours or so it took me to migrate (nearly) everything. 

Flood Risk Reports

Amazon Climate Pledge Friendly  

Number of Cores vs Clock Speed - Which is Better

Number of Cores vs Clock Speed - Summary  

In all instances I have found it better to have more cores, as a opposed to fewer cores, regardless of clock speed. 

Number of Cores vs Clock Speed - Example 

I run a XW8400 and an XW6600. They are both capable of running 8 cores split over two physical processors.  

I have run the XW8400 in two configurations:

• 2 x Xeon 5160 (2 x 2 Core Processors @ 3.00GHZ - Total 4 Cores)
• 2 x Xeon E5345 (2 x 4 Core Processors @ 2.33GHZ - Total 8 Cores)

Despite the significantly lower clock speed, the 8 core set up is:

• Quicker 
• Less Glitchy 
• More Stable 

Number of Cores vs Clock Speed - How Do I Know This 

https://www.cpubenchmark.net/ gives the following marks for the CPUs

• Xeon 5160 - 963
• Xeon E5345- 1868

Both systems are running 16GB RAM and High Quality SSDs. As such bottlenecks from these components are reduced. 

I also really do trash this old PC with modern heavy modelling software & and video encoding. And have found that in all cases the machine is less prone to hang ups, and crashes when run in an 8 core configuration, as opposed to a 4 core configuration. And also completes tasks much moire quickly. 

This is based on 10 years of observations, and using the same machine with 3 different operating systems (XP / 7 / 10). 

Additional 

Why am I using such an old (18 years) PC?

This:

And guess what this 18 year old PC still works really well. Please consider fixing / or upgrading what you already have, rather then adding discarding your equipment and adding to the e-waste problem. 

Environmental Consultants London

Flood Risk Assessment London 

How to Remove a Tangle of Rope or Net from a Beach

How to Remove a Large Tangle of Rope or Net from a Beach

This blog post describes some methods I have used to Remove a Large Tangle of Rope from a Beach. I also go on to describe some other methods you might use. 

I have recently returned from Scotland, doing some volunteer work for People Against Plastic Pollution . For one entire day I worked to remove a 249kg rope tangle that had been thrown above the tide line. 

Rope Tangle Removal Video 

Perhaps the quickest way to show how I did it is with the below video. 

The video shows:

1. Untangling the rope, 
2. Cutting up the rope.
3. Dragging rope to road head.
4. Loading in to trailer.

We also show the rope being weighed. Most people wouldn't bother to do this. 

Untangling the Rope

This is seldom worth doing, but on large ropes it can be worthwhile. Some filament net will be impossible to untangle.

Cutting Up a Tangle of Rope or Net from a Beach

I used a sharp knife to cut up the rope in to manageable chunks. I started off used an Opinel No.6. Which I have always found to be very good, but when it got blunt I switched to a Culinary Victorinox folding knife. This latter knife had a thinner cross section and cut through the rope a lot more easily.

Of course using a knife (although cheap and effective) has a couple of drawbacks. 

• As you saw through the rope you do release some of the fibre that are then too small to pick up. 
• You had will get very tiered. 
• It is quite dangerous, you may cut yourself. 

Alternatives might include:

• Using a "hot knife" to melt through the plastic rope of fishing net. 
• Using a team of people to drag the entire rope of net off of the beach in one piece.
• Using a machine (excavator of tractor bucket) to lift the rope of net off the beach in one piece. 

The below video shows student in South California removing filament net from a beach. 

Dragging the Rope or Net to Road Head 

For most people the route to a disposal point for the rope or net will involve road transport. Luckily on most beaches it is quite easy to drag collected plastic along the beach to a point where a skip, trailer, or truck can be parked.  

However for very remote locations it has been known to use helicopters (see below video), or as we are planning next year a boat to haul out the plastic rubbish from beach. 

Other Ideas for Getting Rope and Net from Beach

Here is a further list of ideas for getting plastic rope and nets from beaches:

• Hire an excavator and to dig out buried rope and net. 
• Use a quad bike and trailer to tow waste off of sure. 
• Use a winch to drag bags or clumps or net and rope along beach (dangerous)
• Dumper trucks (tracked and wheeled)
• Ask a farmer to tow a trailer down to beach. 
• Use a helicopter.
• Use a landing craft to access beach from the sea. 

Preliminary Ecological Appraisal 

Planning Consultants 

Metric Sizes for Fives Court

Rugby Fives Court Size

• Width 18ft (5.86m)
• Length 24ft (7.3152)

Fives Court vs Squash Court 

A squash court is a bit bigger.

• Width 6.4m
• Length 9.75m

Environmental Consultants London

Best Headphones for Bass

This page shows the best headphones with good bass response. These screen shots are taken from RTings.com

It is my birthday next months and I am research which headphones might give best bass for electronic dance music. 

Sennheiser MOMENTUM 4 Wireless Headphones

Please note these were best over ear headphones I could find for bass. And have used these as a benchmark. 

7HZ Timeless

AKG N700NC M2 Wireless

AKG K371

JBL Tune 760NC Wireless 

I actually have a pair of these. The bass is OK.

Sennheiser HD 280 Pro 2016…

I have a pair of these. They are very loud, and clear, and with an equaliser they sound really good for EDM. 

Sony WH-1000XM4 Wireless…

My daughter has a pair of these and they are very good. Very strong bass. 

JBL CLUB 700BT Wireless

The response on these looks amazing. But they are "on" ear. I prefer over ear. 

JBL CLUB ONE Wireless

Conclusions

So after looking at above I will either go for 

Sony WH-1000XM4 Wireless

or 

Sennheiser MOMENTUM 4 Wireless Headphones

Potentially 

AKG N700NC M2 Wireless

Phosphate Assessment 

A Map Showing Various Points of Interest Around Wimbleball Reservoir

Wimbleball for Tourists and Nerds Alike

Wimbleball Reservoir, or Wimbleball Lake. Is an interesting place for tourists to visit, but it is also very interesting for engineers and scientists, as there is a lot of interesting things going on to make it work. 

Please find the below map that shows interesting features. You can click on markers to reveal extra facts and figures. 

Scientific Web Content 

noise management plan