Thursday, October 23, 2014

My experience with the Definitive Technology Studiomonitor 45/65's. Measurements and short Review

My experience with the Definitive Technology Studiomonitor 45/65's. Measurements and short Review

A while ago I did a comparison between the Pinnacle DB 500 and the previous generation Definitive Technology Studiomonitor 350's. I found both to be very enjoyable but the SM 350s suited my tastes more and thus kept a place on my shelf.

When I got the opportunity to buy these new generation Studiomonitors at an insanely cheap price thanks to a lazy Best Buy employee, I couldn't pass them up ($150 for the pair). They immediately went to use in a 2.1 home theater system. I quickly added 3 Studiomonitor 65's as my front 3 and moved the 45's to the rear. In this application they worked well enough, but I always had this sense that they were a little dull; they didn't seem to live up to the reviews, and I kept wanting to go back to the previous generation Def Techs.

So after a while, and after switching to a Pinnacle (BD 650 II/700 II) front 3, I started to focus on the Def Techs as music only speakers, I had such a good experience with the 350's I thought that the 45s and 65's would be amazing. Unfortunately things immediately sounded off, just muddy,dull, lifeless. All those adjectives that someone would use when they are not impressed by a speaker. Many ABX tests with other speakers and a few dozen attempts at in room measurements, I just couldn't figure out why there is such a disparity between my experience with them and all the other positive reviews on the web. I still don't know what in my room that has contributed so greatly to my issues with these speakers and not others.

While the Definitive Technology SM 45 and 65's don't sound or graph all that well in my room, my close mic measurements were nearly identical to what Stereophile produced. So I do not have the ability to say these are bad speakers, only that they didn't work in my situation and it's been a great lesson in trying to listen before you buy.

Album of pictures of speaker and drivers
Album of Graphs

Each graph has two measurements on it. RED is the outdoor close mic measurements, BLUE is the indoor close mic measurements WITH any other driver unplugged. So during the tweeter measurement, the midrange is unplugged and vice versa.

All Driver Measurements @ 1 inch. No smoothing


Port look to be tuned to 45hz. Something loud and ugly is happening between 700hz and 900hz. Not sure of the cause to that, but it is seen again during the midrange response.

Drivers have a steep fall off @ 80hz and crashes to 50hz where there is another bump @ 35hz. Looks like a rather shallow xover at ~2.2khz


Similar shallow xover. Pretty smooth slightly rising response.


Matches very well to the measurements posted by So I'm confident that my close mic measurements are accurate.

Measurements @ 1 meter



The outdoor responses (IN RED) between the 45's and the 65's shared the same characteristics. Keeping the huge hump that exists from 90hz to 200hz. This I imagine was the primary cause of the muddiness. Then the steady decline to 1khz, then a similar climb after 1khz and into the rest of the spectrum.

These speakers just behave terribly in my room (IN BLUE). Even with anticipating room reflections and modes that are going to wreak havoc on any graph, I’m still at a bit of a loss as to why they are sounding as they are.

In my situation, the SM 45s and 65’s sounded and graphed more similar to the Sony B-1000 (

 than my budget favorite Infinity Primus p143 in red. (

I will update to a single picture ASAP

The Def Techs are good looking and really well build. Massive heavy drivers that scream high quality. Their outdoor measurements indicate that they should be very good speakers, but they just do not seem to produce those same results in my room. I'm going to have to assume this is a one off experience and that I'm in the minority here. 

However this has been a great learning experience demonstrating how just one room can drastically affect sound and how if you are willing to spend this amount of money on some speakers you should do your best to try to listen to them before hand and even better see if your retailer of choice has a decent return policy if they don't work for your application.  

For now, I'll be keeping my previous generation Definitive Technology StudioMonitors. Below is a comparison between the 45 and 350's. The 350's are noticeably brighter and louder. This combo seems to not be as effected to my room conditions. 

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