Econowave Speakers

richidoo · April 22, 2012, 03:47:22 PM

Makes sense. I'll do it.
Thanks

richidoo · April 23, 2012, 03:24:57 PM

I didn't do it...

I decided to pursue the AEs in a new project, so they don't further confuse the current effort.

I swapped in the Eminence drivers today. The box and port dimensions now match the Eminence large ported box design. Sounds much better. Still a bit too punchy for my taste, but much cleaner, the boom is much reduced. When the new tester gets here I'll tune the port length to 50Hz. It sounds tuned lower than that now.

I've also been pulling FG out of the box a bit at a time to open it up. Midrange sounds too restrained, muffled. It's getting better.

richidoo · April 24, 2012, 03:15:17 PM

I had too much FG stuffing in the box, it was damping midrange transients too much, and attenuating midrange too much. I'm pulling it out bit by bit and it is opening up.

The bass might be OK as is, if the midrange continues to come up some more. I've removed only 1/4 of the FG so far.

What's something less absorptive I can use to replace it? Black hole, NoRez? Parts Express Sonic Barrier? Gotta be cheap.
http://www.skiingninja.com/Articles.asp?ID=157#norez

Edit: I forgot that I had turned the Sonos bass EQ down by 8dB. When set to flat the bass is still waaaayy too much.

FG reduced to about 1/3 of original, focused around and near the woofer. It sounds more open, no downside that I can hear yet.

Face · April 24, 2012, 05:12:09 PM

Do some nearfield woofer measurements to see where the issue is. Could also be placement/room related.

richidoo · April 25, 2012, 09:14:15 AM

Mike, here's the FR of two speakers. Blue is left, red is right, no smoothing. Right is closer to a sidewall. Mic height between horn and woofer, 1meter from front baffle. Ports installed.

Dip at 200Hz?

richidoo · April 25, 2012, 09:30:38 AM

At couch, 3.3 meters.

Maybe the dip at 200Hz is the problem. It's amplitude 6-8dB equals the EQ I need to apply to bass control to balance the sound.

Fb is supposed to be 50Hz now, according to Eminence. My Fs are at factory spec so the tuning should behave as their sim predicts. New WT3 is shipped but not here yet so I can't measure the impedance to see the exact Fb.

richidoo · April 25, 2012, 05:54:49 PM

This post from AndrewT on diyaudio is interesting. The eminence Qts is .39. Perhaps Viper is right, the Eminence is not ideal for ported box outside of PA duties, and maybe I am expecting too much from it. It sounds great in sealed, so I'll look into that for the Eminences, or just sell them.

The AE's have published Qts .28, so that's well within ported territory.

Face, you are right, longer ports reduce the boom, not shorter. I don't know where I picked that up.

Also more stuffing, not less to reduce the boom, but transient response at midrange frequencies suffers with too much stuffing.

Face · April 25, 2012, 06:23:47 PM

The 200hz dip is probably floor bounce, completely normal.

As for measuring LF extension, you should measure the woofer up close, only a few inches away. It should take room gain, floor bounce, and other reflections out of the equation.

richidoo · April 25, 2012, 06:36:44 PM

Floor bounce, yes that makes sense. Thanks.

I'll do woofer Fr again tomorrow up close

Will that still allow for the port contribution? I guess port radiates omni.

_Scotty_ · April 25, 2012, 06:47:45 PM

Rich,measure the port and then measure the woofer and splice together the two curves.
Scotty

richidoo · April 26, 2012, 07:01:08 AM

Thanks Scotty. I can't splice with REW5, but I can overlay. See attached. Recording level is the same for both sweeps. Mic at center of port exit and 1/2" from center of woofer.

Looks like I should be quite happy with these results, but bass is too punchy and seems too loud. Should I lengthen the ports or just move on to the sealed box that I prefer? Ported speakers that I have owned in the past were rear ports, these fire foward.

richidoo · April 26, 2012, 07:37:50 AM

I played with WinISD again. I simmed the Eminence design that I am trying to copy now. See attached. This is what Eminence recommends for this driver. 78 liter box with two 4x5.5" ports, Fb 50Hz. WinISD predicts 54Hz Fb. Notice the 2+dB bump. This is also shown in Eminence published design. See attached green curve.

My ports are a little shorter, and I don't know what the exact volume is of mine with the foam fill as there are some small voids for air to go, but mostly solid and probably larger than 78l. If I sim 90l with my ports I get 50Hz and the bump is a little less than 2dB. But measuring the port gives SPL peak at 42Hz which puzzles me. Am I confusing port resonance with Fb? Are they the same or different?

Now if I lengthen the ports to 12" to bring the simulated Fb down to 40Hz, the red curve flattens out which is what I want. But since the actual tuning is much lower than predicted, will lengthening bring the actual measured port resonance down too low?

I could also remove the foam to increase the volume, and lengthen the ports but Eminence says 120liter is too big, even though sim predicts it as max flat alignment.

I don't want to do the 12" ports unless there is a chance for improvement. What do you guys think?

The 4th option is to bag these ported Eminences and move on to the ported boxes for AE TD12X for Shanes speakers. I plan to use the Eminences in sealed active speakers for myself anyway.

rollo · April 26, 2012, 07:50:04 AM

Ah to port or not to port. I would give it one more try with the longer ports. Just make shure they are as rigid as possible.
If all fails than a bottle of Port may do the trick.

, Do not give up the Ship yet, you have worked hard so far to get where your at.
If anyone can help Scotty is the one. Got to hear his rig and he has it going on in spades. Knows his speakers.

charles

richidoo · April 26, 2012, 08:58:38 AM

Thanks Charles, yes I agree. We have some great experts here on AudioNervosa. Thanks to everybody who has pitched in along the way.

Face · April 26, 2012, 11:09:56 AM

Quote from: richidoo on April 26, 2012, 07:37:50 AM
I played with WinISD again. I simmed the Eminence design that I am trying to copy now. See attached. This is what Eminence recommends for this driver. 78 liter box with two 4x5.5" ports, Fb 50Hz. WinISD predicts 54Hz Fb. Notice the 2+dB bump. This is also shown in Eminence published design. See attached green curve.

My ports are a little shorter, and I don't know what the exact volume is of mine with the foam fill as there are some small voids for air to go, but mostly solid and probably larger than 78l. If I sim 90l with my ports I get 50Hz and the bump is a little less than 2dB. But measuring the port gives SPL peak at 42Hz which puzzles me. Am I confusing port resonance with Fb? Are they the same or different?

Now if I lengthen the ports to 12" to bring the simulated Fb down to 40Hz, the red curve flattens out which is what I want. But since the actual tuning is much lower than predicted, will lengthening bring the actual measured port resonance down too low?

I could also remove the foam to increase the volume, and lengthen the ports but Eminence says 120liter is too big, even though sim predicts it as max flat alignment.

I don't want to do the 12" ports unless there is a chance for improvement. What do you guys think?

Ports are cheap.

FYI, they may not recommend a larger box due to you running out of x-max quicker. But in a hifi environment, you may be fine.