Doc modding Marantz imperial 7

[karatestu]

All I will say - currently--is the foam will attenuate certain frequencies. Whether that's good or bad only you will know.

You have to find was best for you. I'm loving a cap and a inductor on my midrange. .

Yes that is what the foam is doing. But the interesting bit is when I only block one side of the gap. The frequencies that are being attenuated with the foam in the forward direction are allowed to escape unattenuated in the inward direction. I am trying to work out what theoretical effect that is having. If I can't then it doesn't matter. It is an interesting experiment. Foam is said to lower the speed of sound through it and is generally said to be a bad thing when put between a driver and one's ears. But then most people say that about doping.

What size is your midrange ? Smaller ones will probably be best with inductor and cap. I don't think doping is effective on mids unless they are bigger, like a 5" mid bass which can handle the low frequencies. Glad you are liking it.

[karatestu]

Look at these "cubes". Transparent and with mid bass on opposing sides and magnets coupled together.

http://www.perfect8.com/cube.htm

[Daniel Quinn]

12 inch bass, 5 inch mid and 1 inch tweeter.

The 5 inch mid as got its own seperate enclosure inside the cabinet.

The xover is on the outside, so I can make adjustments.

[karatestu]

A little tip I picked up on pfm

If you suspect one of your speakers is louder than the other (which I have for a little while) then test if it is your ears that are the problem by sitting or crouching facing away from the speakers. If the imbalance switches sides then it is an ear imbalance that is the problem not the equipment.

I tried it yesterday and lo and behold the imbalance switched sides Bloody ears. Now I don't remember this always being a problem so I presume that I have a larger build up of wax in my right ear compared to my left. I have had my ears syringed several times over the years and it looks / sounds like they need doing again.

If that doesn't sort it then it must be due to some other ear problem which probably can't be corrected The only solution in that situation would be dual mono volume controls like the old P90's had.

[TheMadMick]

Stu

Try shifting your seat a little away from the louder speaker. It works. I'm slightly deaf in my left ear and I can get a nicely balanced sound that way.

[Fretless]

I often get a blocked sinus on the left side, especially if I have a cold..
Holding my nose shut and carefully increasing internal air pressure usually fixes it.

Don't force it or your head will explode.

[karatestu]

Stu

Try shifting your seat a little away from the louder speaker. It works. I'm slightly deaf in my left ear and I can get a nicely balanced sound that way.

Thanks, I'll give that a go. Syringing is what I will be looking at initially though. If that doesn't solve it then your solution seems worthy of investigation.

[karatestu]

I often get a blocked sinus on the left side, especially if I have a cold..
Holding my nose shut and carefully increasing internal air pressure usually fixes it.

Don't force it or your head will explode.

Just tried that, several times . It has done something worthwhile and my head is now splattered over the walls of this room. As expected my right ear feels pressurised way before the left

I am going to get some ear drops.

[karatestu]

Imagine something like the above shape to hold speaker drivers How the hell does one make such a thing ? Did it start out as a sphere and then six flat sides were machined off it ?

I thought about how it could be used to mount tweeters and mounted on a short pole above the main enclosure. If the flat sides were just big enough for the tweeter face plates then it would be kind of groovy

Personally I wouldn't use the rear and bottom faces for tweeters, just the front, up and side faces. the rounded corners would help with diffraction and with the whole thing being small it could be mounted on a short pole behind the upper up firing mid bass driver. If it was behind the mid bass like the Linkwitz pluto semi omni then this might help with time aligning the tweeters with the mid bass a little better.

Linkwitz pluto



But there are many pics of the pluto with the tweeter above the mid bass, most with it at the acoustical centre of the mid bass but some with it even further forward (approaching the surround ). There will no doubt be early reflections from a tweeter mounted above the top of another enclosure but this may be preferable to having the tweeter on the sides of the main enclosure many cm's form the mid bass. Thinking about time aligning here

[karatestu]

Spent ages trying to work out how to make a cube with rounded corners. Searched the net for products and couldn't find anything big enough, all the wooden products were at most 6cm3.

Then I realised I should be searching for extra large dice and found this to start with



Wow, turned out to be a big picture That is 15 cm3 and just the right size to mount some tweeters in It's made of foam though which could be a good thing thinking about it. Not sure. Might be worth a go.