DefTech PM 65 vs Kef LS-50

[witchdoctor]

Hi,
Has anyone compared these 2 speakers? Any opinions? I really like the review the DefTech 65 got here on Audioholics but haven't listened to either one. Thanks!

 

[Dr. Bob]

Did you mean the Studio Monitor 65? I haven't listened to that one, but I have the SM 45s at home, and I listened to the LS50s recently in the store, as I discussed here.

Basically, I like the DefTechs for some music, but they seem to get muddled on more complex music. They also sound shrill at times. The LS50s never got muddled, and they had an impressive soundstage, but I found them to be too shrill. Many people love them, though, so you should listen to them both for yourself.

 

[witchdoctor]

I am getting the DefTech SM 65's because they go down to 30 hz and I don't have space for towers. I plan on setting them up just like studio monitors. Thanks for your thoughts. I noticed that the number of LS 50 owners selling their speakers after a few months use was pretty high compared to the SM 65 and I'll bet they notice the shrillness too. Of course they can't say that in their ad. Thanks

 

[GIEGAR]

I am getting the DefTech SM 65's because they go down to 30 hz and I don't have space for towers.

Witchdoctor, just a heads-up: THEY DON'T!

There's no way a pair of 5.25" woofers (with passive radiator) will have an F3 (3dB down) of 30Hz and a bandwidth sensitivity of 92dB/1W/1m. They might be able to achieve either/or, but not both at the same time.

Be very wary of DefTech's published specification claims. Notice in any of the DefTech specifications they state: Maximum Sensitivity and Total Frequency Response. "Maximum" sensitivity could be at just one single frequency and "total" frequency response could mean the limits at which the drivers hardly respond at all. Frequency response figures without reference to a level (-dB) are meaningless... it could be -20dB down for all we know.

I couldn't find measurements of the SM 65's, but you can draw some reasonable conclusions from a comparison of the SM 55's claimed specifications and these NRC Measurements on Soundstage!Network. In summary:

• Sensitivity - Claim: 90dB/1W/1m. Measured: 85.5dB/2.83V/1m (300Hz - 3kHz) (ie. theoretically requires 2.8x power to play at a given level.)
• Frequency response - Claim: "Overall" 32Hz - 30kHz. Measured: -3dB @ 75Hz; -10dB @ 40Hz; -18dB @ 32Hz (all eyeballed).

Sound&Vision's measurements of the SM 55's are kinder, but the overall frequency response profile is quite similar.

The bottom line is, if you're buying the SM 65's primarily for genuine low end extension, you may be sorely disappointed.

 

[zieglj01]

I am getting the DefTech SM 65's because they go down to 30 hz and I don't have space for towers. I plan on setting them up just like studio monitors. Thanks for your thoughts. I noticed that the number of LS 50 owners selling their speakers after a few months use was pretty high compared to the SM 65 and I'll bet they notice the shrillness too. Of course they can't say that in their ad. Thanks

The SM 65 will have some good bass to around 43 hz - however, the loudness
level will fall below that - still decent bass for a bookshelf speaker.
http://www.soundandvision.com/content/test-report-definitive-technology-studiomonitor-sm65-and-sm45-speakers-supercube-8000-1

As far as whether they sound good or not - that is up to your ears.

 

[GIEGAR]

^ Thanks the link Z!

... I'm clearly in need of upskilling in the Search Engine Utilisation core competency.

 

[slipperybidness]

I have the previous model SM350, and they do sound good to my ears.

But, yeah, we all know that the published numbers on the DT line is completely bogus

 

[AcuDefTechGuy]

I think DT & GE speakers sound great.

But their specs are hyperbolized.

When they say it goes down to "30Hz", that's more like 30Hz @ -20dB, instead of -3dB.

But it is still pretty good bass for bookshelf.

If you want more bass in a bookshelf, get one with a built-in active woofer that allows you to turn up the bass gain level.

 

[Cos]

I think DT & GE speakers sound great.

But their specs are hyperbolized.

When they say it goes down to "30Hz", that's more like 30Hz @ -20dB, instead of -3dB.

But it is still pretty good bass for bookshelf.

If you want more bass in a bookshelf, get one with a built-in active woofer that allows you to turn up the bass gain level.

Well not quite 30, but definitely hyperbolized.
I was curious so I started checking the speaker measurements for companies that do +-3db

I found even their measurements do not fall within those limits on the bass side in almost every measurement I checked.

I looked at Monitor / Paradigm and Revel. just for sake of comparison. It definitely is nowhere near as large as DT or GE, but doesn't fall within their own listed specs. but is off as much as 6db for the sites I checked on soundstagenetwork.com

 

[AcuDefTechGuy]

Well not quite 30, but definitely hyperbolized.
I was curious so I started checking the speaker measurements for companies that do +-3db

I found even their measurements do not fall within those limits on the bass side in almost every measurement I checked.

I looked at Monitor / Paradigm and Revel. just for sake of comparison. It definitely is nowhere near as large as DT or GE, but doesn't fall within their own listed specs. but is off as much as 6db for the sites I checked on soundstagenetwork.com

I told Sandy Gross on AVS he should list the +/-3dB specs, but he wanted no part of that.

I don't like that, but I can't judge him because it may be financially damaging to him if he went with +/-3dB specs.

Anyone can email DT customer support and get the +/-3dB spec. But they just don't believe in showing those +/-3dB specs on their website.

For example, DT listed the BP7000SC as 11Hz-33kHz. C'mon man. 11Hz, really? It's simply risible.

 

[Cos]

I told Sandy Gross on AVS he should list the +/-3dB specs, but he wanted no part of that.

I don't like that, but I can't judge him because it may be financially damaging to him if he went with +/-3dB specs.

Anyone can email DT customer support and get the +/-3dB spec. But they just don't believe in showing those +/-3dB specs on their website.

For example, DT listed the BP7000SC as 11Hz-33kHz. C'mon man. 11Hz, really? It's simply risible.

Not sure why he doesn't do that either, but who is really holding any of these speaker companies accountable as I stated in my above post, even the ones that are quoting +-3db, +-2db for Paradigm for example, when you see the third party testing of equipment, they don't fall within those levels. I even looked at RBH, but the only 3rd party speaker measurements I could find were on Audioholics, and those are significantly more than +-3db on the low end the ones they tested, but I also read that those were not ideal testing methods.

Lesson learned is to look for the third party measurements, as I fully agree measurements are important, but if they fall out of the normal range of human hearing, I really don't care how they measure, as long as its flat in the right places.

http://www.guitarbuilding.org/wp-content/uploads/2014/06/Instrument-Sound-EQ-Chart.pdf

 

[AcuDefTechGuy]

Not sure why he doesn't do that either, but who is really holding any of these speaker companies accountable as I stated in my above post, even the ones that are quoting +-3db, +-2db for Paradigm for example, when you see the third party testing of equipment, they don't fall within those levels. I even looked at RBH, but the only 3rd party speaker measurements I could find were on Audioholics, and those are significantly more than +-3db on the low end the ones they tested, but I also read that those were not ideal testing methods.

There is a difference between a few dB discrepancies from companies like Revel, KEF, B&W, Paradigm, RBH vs. what DT & GE publish.

Seriously, who in their right minds would claim that the DT BP7000 goes down to 11Hz?

How can they expect people not to laugh when they see that?

Here is the FR measurement of the RBH 8300/R:
http://www.audioholics.com/tower-speaker-reviews/rbh-8300ser/rbh8300-measurements

You can see that it is about 20Hz @ -3dB even though RBH spec the 8300/R @ 25Hz @ -3dB.

Here is the T30:
http://www.audioholics.com/tower-speaker-reviews/rbh-t-30lse/rbh-t-30lse-measurements-analysis

The -3dB point is @ 18Hz on measurement and RBH spec it at 18Hz @ -3dB.

But I believe we are way off topic at this point, which we are very good at doing.