The new budget speaker king?

[x_25]

Before I go to bed, I thought of another thing you could do to test the PTR theory. You could change the length of the port tube. You could take a paper towel tube or toilet paper tube and slit it down one of the sides and then put it inside the port tube so you can extend the tube out the back of the speaker. Make it something like extending the tube by 1/3 its length. So it is about 10.75cm long, this should change the resonant frequencies. :scratch2:

 

[archie2]

Don't plug the port on these, it'll kill what little bass it has. The sound stage on these continues to amaze me for such cheap speakers. Some of the music seems to come from behind me at times. BTW, if you have the Jurassic Park CD by the London Symphony there is a track on it that has arrows being shot. The arrows will appear to land to the right and left behind you. I have a pair of Spica TC-60's and they are rivaled by these Presidians in soundstaging.

 

[riker1384]

How do we even know the Insignias were "budget kings" in the first place? It may have just been an online marketing campaign that got people talking about them.

 

[analog addict]

Don't keep us in suspense....

Just out of curiosity, when do you plan to drop in the 3uF caps and retest? I'd be curious to see the Freq response graph once this change has occurred. It's puzzling to me why the curve with the 1uF cap looked as good as it did, because I found the high end so lacking with purely subjective listening. I have the modded boxes playing in my office at work right now. Abraxis via computer and a Accurian amp.

Sounds quite reasonable actually....

 

[analog addict]

How do we even know the Insignias were "budget kings" in the first place? It may have just been an online marketing campaign that got people talking about them.

I have a pair of those too, and for $40, they were quite a reasonable speaker also. I wonder if a Insignia vs Presidian test is in order....We can call it Cheapskate's Choice!!!

 

[x_25]

I need another person with two sets of these to confirm some results for me. Take the sets and stack them with the top one upside down (so that the tweeters are one above the other) Then hook the top one up out of phase. Apart from the lack of bass what else do you notice? Also, for this experiment, make sure the top pair is at ear level.

 

[Zilch]

Don't plug the port on these, it'll kill what little bass it has.

We are merely closing the port as a design diagnostic to determine if pipe effect is playing a role in the response.

If there were a bump in the bass response, closing the port might actually help that, but that's not the case here, and it's probably not a reasonable mod.

Just out of curiosity, when do you plan to drop in the 3uF caps and retest?

I've been avoiding showing that because, while it may be part of the solution, alone, it apparently makes matters worse.

Here's the woofer response (Blue) shown along with the tweeter with no filter, with 3.3 uF, and the stock capacitor. It points toward a solution, but the question is whether that 1/2" tweeter is up to the task. Ray will know.

Again, who's making trouble here? Second image shows the stock full range response (Red) with the three tweeter curves superimposed. You're boosting the VHF, but also making a deeper hole between 2 and 4 kHz, even deeper than shown here, because the tweeter responses are not summed with the woofer response as shown.

 

[Robie]

If memory serves, Ray is going to be busy for awhile and may not be able to check in for a couple weeks.

 

[x_25]

:scratch2: Hey Zilch, I was playing with these stacked earlier and was playing with having the top pair out of phase with the bottom pair. Could you so me a favor and try reversing the wires on the tweeter and then testing the speaker as a whole?

 

[Zilch]

If memory serves, Ray is going to be busy for awhile and may not be able to check in for a couple weeks.

Well, we'll just have to blow 'em up on our own, then. :

[Ray's recommended Tang Band will fit, BTW, in that eventuality. It's actually a little bit smaller O.D..... :yes: ]

:scratch2: Hey Zilch, I was playing with these stacked earlier and was playing with having the top pair out of phase with the bottom pair. Could you so me a favor and try reversing the wires on the tweeter and then testing the speaker as a whole?

:nono: You have said the "S" word.

One thing at a time. I gotta go buy the 1.5" port plugz and some 1" fiberglass yet.

[WAIT! That's two things, DUH.... ]

 

[x_25]

:nono: You have said the "S" word.

One thing at a time. I gotta go buy the 1.5" port plugz and some 1" fiberglass yet.

[WAIT! That's two things, DUH.... ]

I said two S words in that post.

Anyway, did you see my post about lengthening the tube?

Also, I am going to go mess with the polarity of the tweeters, I will report back in a few minuts.

 

[x_25]

Ok, I ended up reversing the polarity on the woofer because I couldn't get the plugs off the tweeters. Didn't make any audible difference.

 

[archie2]

Well, we'll just have to blow 'em up on our own, then. :

[Ray's recommended Tang Band will fit, BTW, in that eventuality. It's actually a little bit smaller O.D..... :yes: ]

:nono: You have said the "S" word.

One thing at a time. I gotta go buy the 1.5" port plugz and some 1" fiberglass yet.

[WAIT! That's two things, DUH.... ]

Plugging the port loses the bass, sounds bad. I plugged mine with fiber fill and duct tape. Hooked it up, listened, and quickly removed the plug. Bad idea.

 

[x_25]

Plugging the port loses the bass, sounds bad. I plugged mine with fiber fill and duct tape. Hooked it up, listened, and quickly removed the plug. Bad idea.

The plug is just to test if the tube is resonating at certain frequencies. I measured the tube and calculated it's resonant frequency and the harmonics and they coincided with the spikes in the frequency response of the speaker. We just want to see if the tube has anything to do with the spikes.

Also, Zilch, now that I think about it you will have to plug the tube from the inside, otherwise it will just have a resonant frequency that is half of the current one and the rest of the harmonics will be about the same frequencies.

 

[Zilch]

Ok, I ended up reversing the polarity on the woofer because I couldn't get the plugs off the tweeters. Didn't make any audible difference.

It probably does help, by nulling out the peak at 8 kHz a bit, but I don't generally consider phase interference a rational design tool.

We're not going to get at this via random action. A reasonable approach, virtually a foregone conclusion, is indicated in the curves I've posted. I believe y'all are going after the wrong culprit thus far.... :yes:

Also, Zilch, now that I think about it you will have to plug the tube from the inside, otherwise it will just have a resonant frequency that is half of the current one and the rest of the harmonics will be about the same frequencies.

Yes, that is my intent....

 

[x_25]

We're not going to get at this via random action.

You apparently don't know me vary well. I am the kind of person that keeps trying the first thing that pops into my head until I find something that works.

 

[Zilch]

You apparently don't know me vary well. I am the kind of person that keeps trying the first thing that pops into my head until I find something that works.

Well, look again at the curves. I believe your were on the right track the first time you saw them.

The subsequent tweeter curves point to the same conclusion.... :thmbsp:

 

[x_25]

Well, look again at the curves. I believe your were on the right track the first time you saw them.

The subsequent tweeter curves point to the same conclusion.... :thmbsp:

:scratch2: So does this have anything to do with the 65hz to 9khz range for the "LF" driver. Did they possibly tune the box to try to make it do that and sacrifice speed and bass for it?

 

[archie2]

The plug is just to test if the tube is resonating at certain frequencies. I measured the tube and calculated it's resonant frequency and the harmonics and they coincided with the spikes in the frequency response of the speaker. We just want to see if the tube has anything to do with the spikes.

Also, Zilch, now that I think about it you will have to plug the tube from the inside, otherwise it will just have a resonant frequency that is half of the current one and the rest of the harmonics will be about the same frequencies.

Now I understand.
I agree, I think it's more accurate if you plug it from the inside.

 

[Zilch]

More Data:

Plugged port, 3.0 uF, and off-axis response.

The hole appears, at 4.3 kHz.

Note that red and green are the two units I have, one ported and one blocked. The response anomalies are identical in both.... :yes: