I recently installed the TM65's in my car, and I thought I would add these impressions to Kyle's review. I put them in a couple weeks ago, and they just keep on getting better as they get some time on them.

From my build thread:

"I had a good discussion with my friend Ryan today as I was driving. We discussed the differences in performance between the Thesis drivers and the Stereo Integrity TM65's and the use of the word 'upgrade'.

He pointed out that I'm that guy.....who typically gravitates to the flagship type products......my particular psychosis, "if I get the middle tier, I'll always wonder what the top tier sounded like". So yes, from that perspective, it was an odd thing to see my post to someone who knows me and has followed my audio 'journey'.

I of course discussed the differences between the drivers with Nick in the past, and I had a good discussion with Erin a couple months ago about these drivers. I wasn't sure if when I put them in....I would say, "those are nice - a bit more mid bass" or possibly, "increase in mid bass, but a bit of a drop of 'quality' on the upper portions of the bass tones - towards the top of the bandpass that I'm using them....just doesn't have that quality that the Thesis provides"......

Well....what I AM saying (so far) - incredible performance! An extreme increase in mid bass output that is amazingly clean and accurate. And despite my handicaps (blocked left ear and listening while driving on the freeway), there is certainly no drop in quality on the upper end (low pass of 315 hertz at 24db).

So, now a few details.

Amplifier = Mosconi Zero 3: 270x2 @ 4 ohms; 520x2 @ 2 ohms Mos Zero 3

Thesis = 6 ohm drivers - I've always had a bit of a bias with these drivers - never looked them as mid bass drivers, but mostly a 6.5" mid range. John (minibox) stated they were monsters in his X3 with an extremely good install in his doors. Thesis Sax

SI TM65 = Wired at 2 ohm SI TM65

Our initial listening was with the tune exactly as it was with the Thesis drivers. Nick encouraged me to turn it up to let them run. He also encouraged me to experiment with a little less conservative crossover point/slope.

I had the Thesis high passed at 80hz @ 24db slope, and we immediately moved the TM65's down to 12db slope, and then down to 63hz at 12db. The only difference from 80hz/24db and 63hz/12db was gobs more clean, impactful mid bass sound.

He then encouraged me to mute the sub and try the TM65's without a high pass filter set. This was a bit scary to do at volume, but the drivers were not scared at all - they just did it with aplomb.

So, for the 6+ hours that I drove today, I had the sub muted most of the time, and played just the TM65's with the tweets/mid range. I usually had them playing with 63hz/12db and many times I let them play without a high pass filter. I was extremely impressed with their performance - clean, articulate with no sense of strain / struggle.

Tuning changes were only crossover point / slope of the mid bass, and a corresponding change of point on the sub. Even though my sub is up front, I do feel that I'm getting good benefits of greater mid bass output from the door speakers in my overall bass presentation. I didn't change EQ or T/A, and I was happy to hear the male voices were perfectly (despite my handicaps) centered and in synergy with the tweets and mid range. I didn't hear anything in the tune that was screaming that the mid bass drivers must have changed because things are not right.

So....when stating possible 'upgrade' - a quick note there (nearly disclaimer).

* I went from a 6ohm to a 2ohm driver, so there was greater output of the amplifier.
*I was able to change the crossover point to a slightly lower point, and changed the slope from 24db to 12db - gaining more output.
*I also feel I have more output of the sub even though I moved the point from 50hz @ 12db to 40hz @ 12db - clean, tight sound that blends very well with the TM65's.
*I was concerned that with the possibility of greater excursion I, would end up having a ton of rattles / resonance from the door panels, but there not many, so that pleased me.

Ok....I can barely keep my eyes open and fingers moving.....this was supposed to be a post saying, "they kick butt", but of course I couldn't just say that.....I had to go on, and on......but they do kick butt."