What brand of speakers do most people use for their Sound install?

[Robertj668]

After reading several posts on people asking about adding sound to their Diesel engines I asked myself what sound decoders and speakers do most people mostly use in their installs?
What sound decoders do people use?
I have only used MRC and Tsunami to this point.
For steam I love the Tsunami by Sound Traxx.  It has a great and full sound! I have one in my Pennsylvania K4 4-6-2 Pacific and I just love the sound!
For Diesel Tsunami it still great. They have more choices of sound for your engine. 
But I must admit I do like the cost effectiveness of a MRC they are about half the price of the Tsunamis and your get a nice but bulky speaker. (Yes I know you get what you pay for) I have done several install with the MRC sound that required me to hard wire the sound decoder to a DCC equipped engine. The MRC 1662 and the MRC 1666 are the ones I have used so far.
How do they compare to engines that already have sound installed?
First off if you can afford it or desire to go this route it is a quick and easy way to go. There are so many choices out there.
Having just acquired an Athearn Genesis F7-A and a BLI SD40-2 for Christmas. I had the opportunity to compare between the three.  Yes I think the BLI and the Genesis were better and at that price they should be.  But only paying 30 for a FT-A B&O Diesel and then $30 for sound for only $60 and my time I have a great little engine with sound.
Then getting in the BLI Paragons and MTH that a whole other league. An associate of mine has several of these and wow!
What type of speaker do people use in tight spaces? Any advice?
I ask this question to help me and other that recently seem interested in adding sound to their Bachmann engines (Hint Hint Bachmann. Please add some diesels with sound).
Little or no space in the Bachmann Diesels So what to do?
The engines that seem to come up in the message boards are to me all interior space wise about the same?  A GP38-2 or a SD40-2 or an EMD or even a Morse after I have taken off the shell all have the same problem. No room. So you need to make room. I have chosen to mill the metal frame and make room that way. But I did get for my birthday a Dremmel and have had fun milling the frame for space.
Now the FT-A by Bachmann has a little room for that bigger 1" speaker but it took a lot of milling of the metal frame to do it.  And now I am experienced in the fact that I should have removed the gears of the engine as if you all remember on one of my other questions "why was my not running smoothly anymore.
Finally
I am not an expert but there are many here on this message board. But this subject if a favorite of mine and I wanted to learn and maybe even help out on this subject.  I wish we could make this a sticky note subject and people could reference a particular area for this info. Yes I and other could go to other message boards and I do sometimes from time to time.  But I have grown to trust a lot of you and Thanks to Bachmann for allowing us to talk about all thing model railroading here!
Links
Soundtrax
http://www.soundtraxx.com/index.php?p=home.php
MRC
http://www.modelrectifier.com/index.asp
Thank you for reading this and adding to it!
I was a little hesitant to write this as for criticism on trying to be a know it all, but here it is.

[Heave]

QSI is tops, but are thirsty on power. Digitrax is making new sound units that are cost effective. I can buy a Bachmann Engine with DCC but no sound... throw away the decoder.. yes throw it away, stick a speaker in the tender and harness and I'm off.

I usually stick to buying engines with factory sound. That way they are all in there and it's a one time purchase. All done. Put it on the track and run.