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HTD Level THREE Review (Bookshelf Speaker)

sarumbear

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Also, this HTD is a transmission line, not just a simple port opening.
I doubt it is a transmission line design. If it was it would have 12dB/octave bass roll-off. This looks more like 24dB/octave, which is a vented box response. The impedance response also points to a vented design.
 

MZKM

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I doubt it is a transmission line design. If it was it would have 12dB/octave bass roll-off. This looks more like 24dB/octave, which is a vented box response. The impedance response also points to a vented design.
It better be or they are lying, which seems silly.

As opposed to a simple port tube, our Level THREE speakers include a tuned port with a 1/12 wave internal transmission line. This allows our speakers to produce a warmer tone with more bass than other speakers of similar size.
 

sarumbear

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As opposed to a simple port tube, our Level THREE speakers include a tuned port with a 1/12 wave internal transmission line. This allows our speakers to produce a warmer tone with more bass than other speakers of similar size.
The concept of a transmission line is that there is no tuning, no port resonance.

Also, 1/12 wave length of the resonance frequency 50Hz is 23 inches. It’s a push to fit such a port in a 15x11 inch box.
 
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beaRA

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Actually, the main issue with the Elac DBR-62 was a port resonance at 600 Hz.
I know @amirm noticed a 620Hz resonance possibly from the back panel. Were there additional nearfield measurements suggesting the port was at fault? Regardless, "done in" would be an exaggeration of the effect of the DBR-62 resonance on the overall response. We've seen much worse resonances from poorly implemented rear ports.
 

nick-v

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Yikes
 

Rockfella

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This is the company’s description FYI:



First heard about them from Zeos:

I own an older gen model of the L3 (soft dome tweeter with no waveguide) and it and it’s matching center were my mains for my living room for years, they sounded fine with room correction. I now run I finish R263 & RC263 and if I had to guess I’d say dialogue is a better more intelligible, but the center was a regular MTM, so that’s be expected (I sit off-axis).
This guy never has anything negative to say about anything he reviews. I find it very weird.
 

Astrozombie

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Yikes, i would have said not to pay more than $300 for them because I had a feeling they wouldn't be so hot.............
 

krabapple

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"due to its popularity in home theater forum. "

fads gonna fad
 

Doctors11

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@amirm it would be interesting to review more front ported speakers to see if there are any similarities in port effects. Maybe the Aperion Audio Novus Bookshelf to start. Not too expensive and has some good reviews.
 

Laserjock

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@amirm it would be interesting to review more front ported speakers to see if there are any similarities in port effects. Maybe the Aperion Audio Novus Bookshelf to start. Not too expensive and has some good reviews.
I have
Klipsch RB-61 II Reference Series and Sonus faber Venere 1.5 that are front ported.
Worth reviewing?
 

Dennis Murphy

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I know @amirm noticed a 620Hz resonance possibly from the back panel. Were there additional nearfield measurements suggesting the port was at fault? Regardless, "done in" would be an exaggeration of the effect of the DBR-62 resonance on the overall response. We've seen much worse resonances from poorly implemented rear ports.

I wasn't thinking of the Elac when I referenced front slotted port problems. You brought Elac up, and I was just pointing out that there was what I assumed to be a port resonance. For some reason, Amir didn't provide a nearfield plot of the port, so I can't say for sure. But it seems probable.
 

beaRA

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I wasn't thinking of the Elac when I referenced front slotted port problems. You brought Elac up, and I was just pointing out that there was what I assumed to be a port resonance. For some reason, Amir didn't provide a nearfield plot of the port, so I can't say for sure. But it seems probable.
Understood. I took your initial comment as a generalization that front slot ports are a bad idea. Just wanted to point out there are at least a couple examples of good front port designs in the Elac DBR-62 and Kali IN-8v2. The Elac UBR62 also does well confirmed by @hardisj 's nearfield measurements. Looks like Ascend were able to sort out the Sierra Luna port issues with Klippel feedback as well.
 

Dennis Murphy

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Understood. I took your initial comment as a generalization that front slot ports are a bad idea. Just wanted to point out there are at least a couple examples of good front port designs in the Elac DBR-62 and Kali IN-8v2. The Elac UBR62 also does well confirmed by @hardisj 's nearfield measurements. Looks like Ascend were able to sort out the Sierra Luna port issues with Klippel feedback as well.
Well, let's just say they're hard to pull off. They certainly messed up the response of the Salk WOW, much to my chagrin.
 

Robbo99999

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The first speaker that was deemed unworthy of EQ!? Quite a disaster, not been many frequency responses as jagged as that, and also tonally off. It makes me feel bad for the designers, but I suppose they can do better.
 

pseudoid

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You see? if you bought this item with the greenAX card; you have 90days of "buyer assurance" money-back guarantee.:oops:
A valid example would be [ummmmm...] that it fell off the top of your car and damaged!
An invalid example would be [ummmmmm...] that someone stole it from your car; because that would involve making police/insurance reports and such...
 
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