Understanding subs, levels, and harmonics

[Tomorrow]

I need your technical wisdom again.

I have just hooked up a small sub from the line level out of an integrated amp, via a cdp. Thus, the sub is getting a full-range signal via rca connection. The integrated amp has a crossover, but it can only be used when driving a sub. In this case, the amp is driving the speakers and only passing the full signal via a line out...the amp's crossover is not available. So I'm using the sub's xover.

I fully realize that I can also use the speaker level out from amp to sub to speakers and use the sub's xover in that mode, too.

BUT....since I hooked it up this way, I'm wondering about the sub. It's an 8" and for all the world sounds like it's struggling to put out a full-range signal. Either that, or I'm hearing harmonics of the guitars and voices, including tenors, etc. from it. It's as though the xover's filters aren't working...much. The "high frequency" sources are mildly reserved but LF(ish) sounding (if that makes sense to you). For example, I can hear Greg Allman singing (mutedly) when only the sub is playing, and the speakers are turned off.

I will eventually hook it up using the speaker level inputs, but I'm curious if I will get the same results. Is this distortion from the sub? Harmonics? Bad filters? Normal behavior? What?

As usual, t'anx for your assistance.

 

[Seth=L]

What is the subs x-over set at? If you have it set where your speakers start to roll off you will run into issues. If the speakers are small and you are using the sub for 100hz and below you could have some issues as well. What Sub, Amp, and speakers are we discussing?

 

[mtrycrafts]

I need your technical wisdom again.

I have just hooked up a small sub from the line level out of an integrated amp, via a cdp. Thus, the sub is getting a full-range signal via rca connection. The integrated amp has a crossover, but it can only be used when driving a sub. In this case, the amp is driving the speakers and only passing the full signal via a line out...the amp's crossover is not available. So I'm using the sub's xover.

I fully realize that I can also use the speaker level out from amp to sub to speakers and use the sub's xover in that mode, too.

BUT....since I hooked it up this way, I'm wondering about the sub. It's an 8" and for all the world sounds like it's struggling to put out a full-range signal. Either that, or I'm hearing harmonics of the guitars and voices, including tenors, etc. from it. It's as though the xover's filters aren't working...much. The "high frequency" sources are mildly reserved but LF(ish) sounding (if that makes sense to you). For example, I can hear Greg Allman singing (mutedly) when only the sub is playing, and the speakers are turned off.

I will eventually hook it up using the speaker level inputs, but I'm curious if I will get the same results. Is this distortion from the sub? Harmonics? Bad filters? Normal behavior? What?

As usual, t'anx for your assistance.

To add more info, if that sub has a crossover in it, or a low pass filter that can be varied, its slope determines how fast the frequencies above the set point are attenuated per octave, 6 dB, 12dB, 18 db, etc. That is why you are hearing out of band music in that 8" sub.

 

[Tomorrow]

To add more info, if that sub has a crossover in it, or a low pass filter that can be varied, its slope determines how fast the frequencies above the set point are attenuated per octave, 6 dB, 12dB, 18 db, etc. That is why you are hearing out of band music in that 8" sub.

Mtry/Seth...this is an Energy ES-8 sub I just bought for my little office system. It's a couple of years old (though mint) and not too much info is available online about it, other than the basic specs. Variable high pass filtering provides xover at 50-100 Hz. FR is given at 29-100 Hz @ -3db. I don't know what the attenuation slope is on the xover, but theoretically, the top end frequency shouldn't be so much higher than my set xover point (at 60 Hz) that I can hear tenor's voices. Should it? (The amp is an Emotiva BPA-1.)

LOL, maybe I ought to try this same thing with my two VTF-3's in my main HT setup...that is speakers turned off, subs on.

And just when I thought I was beginning to understand......

EDIT: Point of clarification....the things I'm hearing are reproductions of vocals/instruments with original frequencies that I would guess to be in the 100-500 Hz range.

 

[MDS]

Does the sub have more than one line-level input where one means bypass the xover and the other does not? Unless that xover control in the sub is entirely broken you should not hear voices from the sub with a xover setting at 60 Hz so I'm thinking it must be an issue with the connection to the sub being the one that bypasses its internal xover.

 

[Tomorrow]

Does the sub have more than one line-level input where one means bypass the xover and the other does not? Unless that xover control in the sub is entirely broken you should not hear voices from the sub with a xover setting at 60 Hz so I'm thinking it must be an issue with the connection to the sub being the one that bypasses its internal xover.

MDS, the sub does have a second input, that is utilized for a signal using an external xover. I'm feeding it a full-range signal, so I'm using "sub input". When I plug the rca into the "xover input", I REALLY do get a full-range reproduction (to the best of the sub's ability, that is). With the rca in the "sub input" the xover control seems to work (or is trying to), but I still hear muffled voices, no matter the frequency of the vocalists. If I didn't know better, I'd say these were harmonics. But maybe I don't know better, lol.

Oh, I did find out, the low pass filter slope is 18dB/octave.

I'm so confused why these sounds are there. And Energy tech support has no idea. (Why did I know that before calling?!)

 

[annunaki]

Do you have an SPL meter? D you have a cd with multiple frequency test tones on it?

1) Test the sub at 60 hz (Be sure to measure near the cone). 2) Then test it at 120hz. The output level should be 18db less than the level at 60 hz (if that is your x-over setting). 3) Then test at 240hz. This level should be 36db below the level at 60 hz. If it is not, or at least really close, it sounds like there is a problem.

 

[mtrycrafts]

MDS, the sub does have a second input, that is utilized for a signal using an external xover. I'm feeding it a full-range signal, so I'm using "sub input". When I plug the rca into the "xover input", I REALLY do get a full-range reproduction (to the best of the sub's ability, that is). With the rca in the "sub input" the xover control seems to work (or is trying to), but I still hear muffled voices, no matter the frequency of the vocalists. If I didn't know better, I'd say these were harmonics. But maybe I don't know better, lol.

Oh, I did find out, the low pass filter slope is 18dB/octave.

I'm so confused why these sounds are there. And Energy tech support has no idea. (Why did I know that before calling?!)

How close are you to the sub when you hear this out of band music? How loud do you think it is? As you go up in frequency you are more sensitive to them. We all are confused at times, don't worry, you are not alone

 

[Tomorrow]

How close are you to the sub when you hear this out of band music? How loud do you think it is? As you go up in frequency you are more sensitive to them. We all are confused at times, don't worry, you are not alone

The sound of the "harmonics" is not as loud as the primary LF the sub is producing. They do become louder as I move the xover control up. In fact everything becomes louder, but especially the stuff I feel shouldn't be there. I did this same test to my main system with HSU subs, today. There is no similarity of sound...that is there are no voices or other higher frequency signals being produced using the same music I've been listening to on the office system.

You can hear these sounds from across the 12x12 office room, btw. The totality of sound coming from the little Energy makes it's tighter LF thumping mushy with blended 'other' sounds. Grrrr.

 

[Tomorrow]

Do you have an SPL meter? D you have a cd with multiple frequency test tones on it?

1) Test the sub at 60 hz (Be sure to measure near the cone). 2) Then test it at 120hz. The output level should be 18db less than the level at 60 hz (if that is your x-over setting). 3) Then test at 240hz. This level should be 36db below the level at 60 hz. If it is not, or at least really close, it sounds like there is a problem.

Annunaki, I do have an SPL meter. But my I only have a dvd with a frequency scale on it. My office rig only includes a cdp. Can you recommend a source for an mp3 (legal) download, or cd source? Appreciated.

Yeah, I'm afraid there is a problem. It's funny about the Energy tech support people. They told me "they just bought the company" and have little experience with this model. HUH? I didn't question them further....should have.

 

[annunaki]

Annunaki, I do have an SPL meter. But my I only have a dvd with a frequency scale on it. My office rig only includes a cdp. Can you recommend a source for an mp3 (legal) download, or cd source? Appreciated.

Yeah, I'm afraid there is a problem. It's funny about the Energy tech support people. They told me "they just bought the company" and have little experience with this model. HUH? I didn't question them further....should have.

Unfortunately you are asking the wrong person about downloads for tones and such. I purchase all of my music on cd. I have not ventured into the downloading arena for various reasons.

Perhaps there are others here who could help in that regard?

 

[mtrycrafts]

The sound of the "harmonics" is not as loud as the primary LF the sub is producing. They do become louder as I move the xover control up. In fact everything becomes louder, but especially the stuff I feel shouldn't be there. I did this same test to my main system with HSU subs, today. There is no similarity of sound...that is there are no voices or other higher frequency signals being produced using the same music I've been listening to on the office system.

You can hear these sounds from across the 12x12 office room, btw. The totality of sound coming from the little Energy makes it's tighter LF thumping mushy with blended 'other' sounds. Grrrr.

Well, no matter the slope, you should not hear it across the room. Does that sub have a level control on it? Where is it set? Maybe experiment with that if it has one. Starting to run out of possibilities.

 

[Tomorrow]

Well, no matter the slope, you should not hear it across the room. Does that sub have a level control on it? Where is it set? Maybe experiment with that if it has one. Starting to run out of possibilities.

Yeah, level control is set to very low....just high enough to aid the ACI's with the bottom octave, but not so much as to bug me with the "extra", "bonus" audio.

It integrates with the ACI's better than you'd expect, given my whining about this....when kept low. It is probably a much better HT sub than musical performer. It's got tons o' punch. It's just that I keep hearing voices. LOL!

 

[Tomorrow]

I guess I've come to the conclusion that I've just been spoiled by my Hsu's. This little guy is okay for HT, but not for snappy music presentation.