5 replies to this topic

[Carlspeak]

Visit the link below for a write up of my latest project.
I've revived a KLH-17 e-wave thread to show a picture and test curves of my first completed speaker. A second will soon follow and listening impressions as well.

http://www.audiokarm...140#post3873140

[JKent]

Interesting Carl
I bought the EWave boards a while back because I'd really like to try that project--just not sure what speakers to sacrifice.
Here's a question (undoubtedly there will be more): Why did you use the PE woofer + ports instead of the stock 17 AS woofer?
Kent

[Zilch]

I've revived a KLH-17 e-wave thread to show a picture and test curves of my first completed speaker. A second will soon follow and listening impressions as well.

No clue yet how it sounds or whether you like that or not, but it appears to be performing substantially in accordance with the design documented in the thread....

[Carlspeak]

Interesting Carl
I bought the EWave boards a while back because I'd really like to try that project--just not sure what speakers to sacrifice.
Here's a question (undoubtedly there will be more): Why did you use the PE woofer + ports instead of the stock 17 AS woofer?
Kent

Hi Kent.
I'll refer you to Zilch's posts in that thread. Somewhere along the way, he showed the PE woofer to perform better with improved bass extension. I simply followed his final design and for two reasons. The design was 'proven' and I wanted to provide an independent verification of that design.

How the speakers sound overall is another matter which I'll be addressing in the future.

[Carlspeak]

I've completed my listening impressions and found them as built per the KLH 17 thread to be too boomy at the low end for my tastes. I also sensed a 'hole' in the mid-bass response. As the NF woofer response I posted shows, it's response is rather limited from it's natural roll-off on the low end to just over 170 hz.

With the fine sounding Selinium DT220i compression driver rolling off with the HP filter at around 2 kHz, it would seem the output below 1 kHz down into the 200-300 hz range would be depressed and, it sounded like it.

I first tried plugging the vents and noticed less boominess. I then tried a few modifications to the LP filter to extend it's response upward with no audible success. I went back to Zilch's original LP but added some FG stuffing to the now-sealed box. That lowered the Fc 5 hz to 58.

Both speakers were modded with the plugged ports and added FG. Another round of listening tests were conducted using acoustic music. There still seems to me to be some lacking of mid-bass. However, I feel Zilch's original e-wave design will make most listeners of contemporary and rock music happy. For those wanting better overall response thru the mid-bass range, perhaps a different woofer should be considered that doesn't have a nasty 2 kHz response peak. If I still had the original woofers, with their less than ideal bass extension I would probably re-install them.

Maybe, a 3-way design should be considered for larger e-wave designs (LA's and NLA's) where the edge breakup of most modern woofers presents a challenge of crossing them high enough to avoid the mid-bass hole or risk a respose hump in the 2 kHz range.

[Zilch]

Thank you for your review, Carl. I also found that closed-box, the DC250 played a little flatter at the low end. The biggest difference came with using them without boundary reinforcement, i.e., on stands out from the wall(s).

You can see in the AK thread that finding a flatter-low-frequency contemporary woofer that'll play extended bass in these small boxes is a challenge. From the curves I presented there, it looks like JBL LE10 might come closer to matching your preferences. You might try KLH-6 woofers, as well.

Time permitting, I'll give DC250 another try using PCD; my lowpass incorporates a substantial amount of BSC to achieve "contemporary" voicing in the small KLH-17 alignment, which you are experiencing....