Event Horizon: a slim, wall-mounted WMTMW

[PWR RYD]

Re: Event Horizon: a slim, wall-mounted WMTMW

IMHO I think the B4N sounds better than the ND105-4, regardless of bass extension.

[Paul Carmody]

Re: Event Horizon: a slim, wall-mounted WMTMW

I have finally made some good progress on this project.

First, like I said, I was kind of bummed that the ND105-4 wanted a bigger cabinet. I just couldn't get over the fact that I wanted the bass to dig deeper. So I went back to my old standby, the HiVi B4N. It was up to the task, and was able to squeeze out that last bit of "oomph" that I felt was needed in the 50-100 Hz range. I'm finally getting that "deceptively big and engaging" sound I was hoping for from this project. (I know I'm doing things right when I want to stay up late, listening to CD after CD)

Using the HiVi B4N brought some good advantages:
1. It's cheaper than the ND105-4 (and no neodymium, which is a plus in our current "scarcity crisis")
2. Two of them in parallel give a healthy amount of sensitivity. I'd estimate the HiVi version to be around 87-88 dB. This means I can get more output out of a smaller amp.
3. They look pretty cool paired up with the HiVi B3N in the middle.
4. No rear-mounting at all. This simplifies cabinet construction.

But of course, TANSTAAFL
1. Because the magnets are so big (especially on the B3N), the drivers just don't fit into my original cabinet. And I've tried everything with regards to moving around internal walls, and just can't make it all fit. So, I'll have to build NEW cabinets--probably about 1" taller. (I had to jury-rig things a bit just to get it temporarily working)
2. This is, without a doubt, a "4 Ohm nominal" speaker. It's not too taxing on an amp. It doesn't dip terribly low--but it doesn't get very high either.

So here's where I'm at now...
I'm just not happy with the way the Dayton ND drivers perform in this size enclosure. I do have a tall, thin floorstanding cabinet that I would like to try the Dayton ND design in in the near future. As a wall-hanging speaker, however, I think the ND version just might be too big for some tastes. The ND105-4 want a bigger box--at least 2 Liters more, overall. And while that may not sound like much, it is when you're trying to stay thin and stylish. Maybe it's just my own perfectionism, but I'm trying really hard to keep these as shallow, narrow, and short as possible. Every 1/2" counts.

I have to scrap my cabinets (again) in order to make the HiVi woofers fit. Third time's the charm, though, right? At that point, my wife might--finally--have her speakers she always wanted.

[michiganpat]

Re: Event Horizon: a slim, wall-mounted WMTMW

Life's hard sometimes.



:D

so Johnny's wife is a size queen? ;)

[Ryan_M]

Re: Event Horizon: a slim, wall-mounted WMTMW

Sometimes I wish I could talk my wife into letting me go in/on-wall but she likes big speakers:D

Life's hard sometimes.



:D

[DDF]

Re: Event Horizon: a slim, wall-mounted WMTMW

Dave,
I'd be glad to share some measurements with you.

Hi Paul,
Friendly reminder, wondering if you could please post that single point measure?

Thanks,
Dave

[fastbike1]

Re: Event Horizon: a slim, wall-mounted WMTMW

I do recall folks posting some later (about the time the ND-105's went on sale a second time) measurements that seemed like the Fs had gone up. PE Posted specs on these have been all over the map between catalogs and the site.

Is/was a modern Bonnie. Ended up powder coating most of the shiny bits to black. Sadly, was just too slow, too heavy, and not enough brakes. Replaced it with a Tiger. Almost as much go as a Speed Trip, but more civilized accommodations.

You're right I should have caught that, it was posted quickly. However if you knew that you should have mentioned it to not throw off people with possibly misleading interpretations of my numbers.

BTW. the results were verified by a second test kit at the same time, so I'm pretty confident in them. Batch to batch variation?

OT is that a modern Bonnie in your avatar? Nice looking bikes. Test rode a Striple R and got thaaaat close to retiring the 6R.

[DDF]

Re: Event Horizon: a slim, wall-mounted WMTMW

I'm aware of that. However when you post params like that, it throws people off and puts your measurements in doubt.
My set of measurements are in agreement w/ Chris' set (quite a bit lower Fs).

You're right I should have caught that, it was posted quickly. However if you knew that you should have mentioned it to not throw off people with possibly misleading interpretations of my numbers.

BTW. the results were verified by a second test kit at the same time, so I'm pretty confident in them. Batch to batch variation?

OT is that a modern Bonnie in your avatar? Nice looking bikes. Test rode a Striple R and got thaaaat close to retiring the 6R.

[fastbike1]

Re: Event Horizon: a slim, wall-mounted WMTMW

I'm aware of that. However when you post params like that, it throws people off and puts your measurements in doubt.
My set of measurements are in agreement w/ Chris' set (quite a bit lower Fs).

Ignore the Sd it only affects Vas, which wasn't measured (the value was a holdover from an older calculation)

[SicSona]

Re: Event Horizon: a slim, wall-mounted WMTMW

I have another option for rear mounting small drivers with no exposed screws on the front baffle. This is similar to tdv's idea but saved some fabrication. For some ND90s, I used sash clips designed for holding screens or windows in storm doors. They are actually pretty sturdy. I attached them to threaded inserts installed in the back of the baffles just outside the recess for the driver frame. I also added a camfer to the front using a 45 degree bit which I thought added a nice touch.

[DDF]

Re: Event Horizon: a slim, wall-mounted WMTMW

I know they have great bass, but the Sd in your measurements is more typical of an 8" driver. It should be around 51 rather than 235.

Ignore the Sd it only affects Vas, which wasn't measured (the value was a holdover from an older calculation)

[superspeeder]

Re: Event Horizon: a slim, wall-mounted WMTMW

Nice work! I plan to do something similar with my HT speakers, rear mounting them to hide those frames...

I was wondering if PE would consider releasing an upgraded version of these drivers for a bit more $ and a nice cast frame, but the introduction of the "still ugly" ND91 seems to have put that dream to rest.

[fastbike1]

Re: Event Horizon: a slim, wall-mounted WMTMW

I know they have great bass, but the Sd in your measurements is more typical of an 8" driver. It should be around 51 rather than 235.

Hi Paul,
Sorry, I must have missed this post first time around. "JD" = "Jack Daniels" carboard box (it was done quickly!), but it was actually a Vodka cardboard box (less coloured sound contribution? )

Here's what I found:
"Title: Measured Data"
"Method: Box-loaded (20.00 liters)"
"DCR mode: Measure (-0.02 ohms)"
"Area (Sd): 235.00 sq cm"
"Series resistance: 75.75 ohms"
"Stimulus level: 1.00 volts"
0.134 "RMSE-free Ohms"
71.212 "Fs Hz"
3.951 "Re Ohms[dc]"
31.492 "Res Ohms"
4.748 "Qms "
0.596 "Qes "
0.529 "Qts "
0.488 "L1 mH"
0.535 "L2 mH"
1.489 "R2 Ohms"
0.127 "RMSE-load Ohms"
0.000 "Vas liters"
0.000 "Mms(Sd) grams"
0.000 "Cms(Sd) æM/Newton"
0.000 "Bl(Sd) Tesla-M"
0.000 "SPLref dB[Re]"
0.004 "Rub-index "

Curious if you saw the same break up signature.

Thanks!
Dave

[DDF]

Re: Event Horizon: a slim, wall-mounted WMTMW

Dave,
I'd be glad to share some measurements with you. For my projects, I tend to take measurements from a single point on the listening axis, but I can easily go back and take some more of just that driver.

What's a JD box?

By the way, did you measure the T/S of the ND105-4? Did anyone? Usually, Dayton's spec sheets are pretty accurate, but I never verified it with this driver myself.

Hi Paul,
Sorry, I must have missed this post first time around. "JD" = "Jack Daniels" carboard box (it was done quickly!), but it was actually a Vodka cardboard box (less coloured sound contribution? )

Here's what I found:
"Title: Measured Data"
"Method: Box-loaded (20.00 liters)"
"DCR mode: Measure (-0.02 ohms)"
"Area (Sd): 235.00 sq cm"
"Series resistance: 75.75 ohms"
"Stimulus level: 1.00 volts"
0.134 "RMSE-free Ohms"
71.212 "Fs Hz"
3.951 "Re Ohms[dc]"
31.492 "Res Ohms"
4.748 "Qms "
0.596 "Qes "
0.529 "Qts "
0.488 "L1 mH"
0.535 "L2 mH"
1.489 "R2 Ohms"
0.127 "RMSE-load Ohms"
0.000 "Vas liters"
0.000 "Mms(Sd) grams"
0.000 "Cms(Sd) æM/Newton"
0.000 "Bl(Sd) Tesla-M"
0.000 "SPLref dB[Re]"
0.004 "Rub-index "

Curious if you saw the same break up signature.

Thanks!
Dave

[DIYNut42]

Re: Event Horizon: a slim, wall-mounted WMTMW

These are looking great Paul! Bet they will really sing. I'm one that doesn't care for the ND Driver frames as well. Rear mounting these makes em look good. I ended up making a 1/8" thick plastic faceplate for my AviaTrix MLTL's just to hide the frames. Actually a pic of one of them is in my avatar. Guess I should probably get that build thread up soon... :rolleyes:

[lostboy77]

Re: Event Horizon: a slim, wall-mounted WMTMW

So... back to the project at-hand. I did some RTA measurements of the Event Horizons, and I'm getting an F3 in the upper 50 Hz range. Is this workable? Of course. I was just hoping for an F3 in the mid 40s. But I guess if I really want that kind of bass response, I'll have to use the Seas Excel W12 :rolleyes: or do a HiVi version.

In 4.25l, with a tuning of 50Hz, I am getting an F3 of 48.75Hz. This alignment had a gradual and smoothly increasing roll off. Correct me if I'm wrong, but being on wall speakers, the added room gain should pull this up to an actual F3 nicely in the low 40s, maybe even the high 30s. If you add 6dB to 40Hz (typical of close boundary room gain) you are 2dB down from reference.

These may to better than you think.