Chienmortbb

Do you know of a 12" that can really exceed 400W RMS at low frequencies?

Despite manufacturers claims to the contrary, there is not I never said it was Samsung ..............................but it w*s

The MB200 uses the ICEPower 50ASX2 BTL, 170Watts into 4 ohms and 100 watts into 8 Ohms.

One of the reasons I would avoid 2 ohm operation. Its too close to a short for my liking. I also agree about protection, its like contraception. Not 100% effective. My dad got an apology from the condom manufacturer when I was born

I well remember when at Panasonic that a certain company (Korean company beginning with S) claimed a huge brightness figure for their Plasma screens. How did they do it? By reducing the size of the white area measured. The power supply of plasma screens could not maintain full brightness over the whole screen so the smaller you could make the measured square, the brighter the picture. They reduced the square from 2.54 x 2.54cm to 1 x 1 cm and hence the power supply could maintain a higher brightness. Your calcs on the Bugera are about right.

Marshall is better.

I have tried all of them and now use KICAD. They all have a learning curve though.

It is, its a Leathergraft Softy 4" wide. However it is longer than the standard length as at one time they had an extra long option on their site. I ordered one and it was too short. They reealised that they had put the wrong length online. They do an XL 2.5" but they had to go a hand made version for me. I have asked if they could make another but they have not got back to me yet. https://leathergraft.co.uk/shop/ols/products/the-softy-guitar/v/2.5 XL Soft Blk

I was tempted but I visitrd Absolute Music this morning and the had the TGI at £49. I also looked at one of my gig bags and it is only the tag of the zip that is damaged so I will put some string through it and live with it for the time being,

What have rear ports and tweeter ever done to you? There is nothing intrinsically wrong with rear ports although they do need care with cabinet placement. Tweeters are neutral, It is the implementation of a tweeter that matters not tweeters per se.

The mic mechanic is great. As for the Zoom B1 Four, It has behaved itself ever since.

Piezos do not hiss.The amp hisses, the piezo just puts out what it is fed.

i never use the straps as i am 6ft 2in and always forget when walking through doors. I only really need the bags to get from car to venue. I have a Hiscox hard case. I cut the straps from the Tribal Planet gig bag (they don't seem to be around now), It would be fine but the zip has gone. I was looking at the TGI https://www.absolutemusic.co.uk/tgi-extreme-series-electric-bass-guitar-gigbag.html at least I can go and have a look at it first as Absolute are only about five miles from me. As the Fender ones are also in stock I will check them too.

But woefully supported here in the UK?

Clearly there is some benefit to these “Tea Chest Bass” systems but for a band they are not ideal. One local band has three of the Bose Systems and that works quite well but for that money it woul be easy to buy a far superior system. I saw a guitarist at our local using a Yamaha last week and it could be that he did not know how to use it but it was so distorted I made me wince.

I need two new gig bags, the two I have have only lasted 20 years, nothing lasts these days..,, So Mono make good bags but I already have a mortgage. Any ideas?

It is a thing but only in big venues with flown line arrays.IMHO

I have been looking at those. More later.

No but it is a good point. Smoke (without fire or exploding semiconductors) is often used to check airflow in various industries.

This is taken from my build diary and posted earlier today. I post it again here as I think it is relevant. "I have done some experimentation myself with fans and the noise. .............. turbulence caused by the fan is what helps the cooling. Of course, turbulence means noise BUT I found that most of the noise is caused by vibration. Sadly the metal used on most amps is a great sounding board and makes the noise problem worse. I have managed to reduce the noise on fans on some amps using rubber mountings from AKASA and you can get low noise fans from companies such as Noctua. The Noctua Fans are well made but to get the lowest noise you have to use an adapter that reduces the speed, probably by reducing the voltage applied to the fan. Noctua do take care to reduce vibrational noise as far as possible but you pay for this extra and the fancy packaging." In short there is no such thing as a silent fan but by selecting the airflow/voltage carefully and reducing the vibration transferred to the chassis you can reduce noise a lot. Also two low spead fans may be better than on fast fan but surely the old Stage/Studio switch that simply switched the fan off could work well?

To be fair outsourcing repairs is not new and need not be a bad thing as long as the company are well trained. My old company, Panasonic, outsourced some product ranges to a company started by two ex-Panasonic Service Engineers, Multicare. They are now doing repairs for many companies including JBL, and also take in consumer repairs.

There are issues with the enclosure I am using with regard to heat dissipation. If you look at the side panels, you will see that the extrusions are horizontal rather than vertical and I don't want to put fans on the outside. So fans must be inside but inside the panels and heatslugs of the amp modules are smooth. The question is, do I attach heatsinks inside to create something that a fan can work on, or would a fan just blowing air through the case help? Rod's article suggests not. Extra heatsinking will add weight and although the whole thing is not heavy, the enclosure alone already weighs 2Kg.It also does need a small amount of extra circuitry to drive the fans so I have to decide whether the extra weight and mechanical and electrical complexity are worth it.

To explain a bit more. These old Ramsa WS-A80 speakers are passive and rated at 80 watts RMS but are 20 years or more old. They were conservatively rated. However the amps are capable of well over 300 watts into 8 ohms. So I had to be careful. Add the fact that I was in a shed and that I value my ears... So the A input was fed from the Main L output from my mixer and the B input was fed from the R output of my mixer. Despite the outside temperature being close to 30 degrees C, after half an hour the sides of the amp case were only warm to the touch. I will do some proper temperature measurements soon but as a rule of thumb, 30-40 degrees is warm 50-60 is hot but 60 is just about OK to touch without burning. 70 degrees is too hot to keep your fingers on. Based on this, I guess the temperature was under 40 degrees. A word about fans. Many bassists hate fans but there are pros and cons. According to Rod Elliott of the Audio Pages https://www.sound-au.com/heatsinks.htm#s18 fans have to blow not suck. Section 18 of the article details Rod's conclusions on fans. I must admit that I cannot find the source but I have it in my mind that a fan cooled heatsink can remove 4 times as much heat as one passively cooled just by a heatsink if placed correctly in relation to the heatsink, I have done some experimentation myself with fans and the noise. Again if you read Rod Elliott's article, he says that the turbulence caused by the fan is what helps the cooling. Of cause turbulence means noise BUT I found that most of the noise is caused by vibration. Sadly the metal used on most amps is a great sounding board and makes the noise problem worse. I have managed to reduce the noise on fans on some amps using rubber mountings from AKASA and you can get low noise fans from companies such as Noctua. The Noctua Fans are well made but to get the lowest noise you have to use an adapter that reduces the speed, probably by reducing the voltage applied to the fan. Ho Noctua do take care to reduce vibrational noise as far as possible but you pay for this extra and the fancy packaging. I have tried Gelid low noise fans and found that apart from the white fan blades, they give no advantage over traditional fans. To reduce noise you have to have rubber mountings and/or run the fans at a lower voltage and hence a lower speed. This of course reduces the cooling efficiency of the fan.

Do you mean my last post or all of it?

Yes I could have used either method but as the modules have a balanced input, I was going to just reverse the XLR hot and cold cable on the B channel via the slide switch.