Lack of bass

[Flyman]

Hey guys

 

a bit weird situation. I have the c7es3 and before a year i take a demo amp hegel h190 and some others. I felt with hegel a more bass from anim,lfd,cyrus.a lot.

 

so i decide to buy  the hegel h190. Unfortunately when i buy it there was no bad at all. I speak to the dealer saying that i must burn it some hours.nothing happens....! I don't know if the demo had some changings or mine have some problems. Some friends of mine have some bookshelf have more bass from me. So big cabin and 7 inch woofer must have a good bass shake.am i right?

 

a guy told about the hegel that is hydrid ....that's why it has so big damping factor....what's why i don't have bass because of hybrid.

 

Any thoughts?!

[esldude]

So you had the Hegel H190 to demo at your house with the Harbeth speakers and plenty of bass, but purchased a new H190 and not enough bass?

 

Seems unlikely the amp would function except for bass.  Have you moved the Harbeth speakers?  Maybe you have them in a poor position for the room they are in.

[Flyman]

I didn't change anything. My main problem is the lack of bass for some reason.

 

After that i change many possition finding the best for bass. I am not happy from any possition ...even having them close to the main wall.

[Ralf11]

but you changed wiring connections, right?

 

 

[esldude]

Is possible you have them wired out of phase?  The leads flipped on one vs the other would cause poor imaging and bass would somewhat cancel out.  

 

 

 

 

[Flyman]

out of phase...meaning the +and the -?! I check them the red in the red and the black in the black.

 

The only change that i make is from rca to xlr....but i did't notice changes in bass.in xlr plays much better more clear.

[PeterSt]

1 hour ago, Flyman said:

out of phase...meaning the +and the -?! I check them the red in the red and the black in the black.

 

I would think the other way around : the wiring in the new amp can be wrong. Thus, deliberately change one channel to how it should NOT be (red in black and black in red).

[Flyman]

I don't know why i don't have bass.

 

Maybe the demo amp was with some upgrades from the dealer.maybe...but my system doesn't have bass at all.

[semente]

Did you move the speakers or the listening spot?

 

Also try Peter's suggestion and invert the cable connection ( + -> + / — -> — to + -> — / — -> + ) at the speaker end only of one of the speakers).

[Flyman]

i try it...when what i supposed to check?!

[Flyman]

well guys...i think i find it.

 

I have a dedicated line for the hifi with 4mm simple cable. When i plug it to the wall i have a lot of bass...and from my line a have airly highs.why is that?!

 

i member before years i read some guys have the amp in the wall and the other to dedicated line. any thoughts?

[fas42]

Your rig components, like in most audio systems, are sensitive to the quality of the mains power. Shouldn't be that way, but under-engineering is the name of the game in hifi. Either, condition and filter the power being fed into each box to the level necessary to solve this, or replace the components you have with ones that are more robustly engineered - are two straightforward solutions.

[PeterSt]

4 hours ago, fas42 said:

Either, condition and filter the power being fed into each box to the level necessary to solve this, or replace the components you have with ones that are more robustly engineered - are two straightforward solutions.

 

Frank, man, what a BS ...

[PeterSt]

8 hours ago, Flyman said:

i member before years i read some guys have the amp in the wall and the other to dedicated line. any thoughts?

 

It probably isn't going to help you, but this is basic "audio set up matter". Say that it is all groundloop related (not stating that a groundloop as such is audible, although that can surely happen too, as mains hum or other noise and noises). It is related to how your audio devices interconnect and I don't refer to the audio cables. What I do refer to is how all devices connect via the mains and how this can be right or wrong without a recipe in advance except for trialling (for least hum or best sound).

 

If the devices connect "wrongly" then current will be flowing over your audio cables (including USB or SPDIF) and the music signal is subject to that (also the digital signal from USB or SPDIF is). The general dimensions you are dealing with are:

 

- the polarity of the power cables (this relates to how the polarity of the wall socket was done);

- The connection to Protective Earth (PE) or not (this is always your choice, unless the socket doesn't carry PE);

- The latter with the explicit notice that you'd have to try that for all the combinations possible (each device normally has two choices unless it doesn't have a PE connection in the power cord / inlet);

- While one device may connect to PE (or none, or several), you can still imply the devices to inter-connect via PE to each other (create a special power extension block for that, with say 5 sockets PE connected and 5 not, the power cord of the block itself carrying PE.

 

That's about it. I didn't do the math, but for say 5 different devices you may end up with 100s of permutations if you don't rally know what to head for.

 

In my younger days I tended to solve things by means of ground wires from or to everywhere. This is a simpler and faster solution. But at least by such means you really don't know what you're attacking and solving - except for that it may help in quick fashion. The downside is that you will never know how much more can be improved because you are not working on something with sense.

 

As I said, this may probably not help you at all. But it is the basics for good audio sound quality. It is part of the hobby too, because you will really achieve things. You coincidentally achieved something because you had a problem. But a 10000 to 1 you an achieve much more by the very same means (the 100s of permutations).

[gmgraves]

23 hours ago, fas42 said:

Your rig components, like in most audio systems, are sensitive to the quality of the mains power. Shouldn't be that way, but under-engineering is the name of the game in hifi. Either, condition and filter the power being fed into each box to the level necessary to solve this, or replace the components you have with ones that are more robustly engineered - are two straightforward solutions.

Bullpuckey! You are confusing the OP! There is nothing one can do that would change the quality of the mains power enough to affect the bass. Based on the OP’s description, the mains voltage would have to drop precipitously* in order change an amp’s performance that much from the demo unit to the purchased unit!

I find that the “out of phase” explanation is much more compelling than yours. It is possible (though unlikely) that the manufacturer accidentally swapped the internal wiring of one channel at the speaker connectors. The OP can easily check that by swapping the connection at ONE end of ONE channel (either at the speaker end or the amp end, whichever is more convenient). But change one end only, not both, and on one channel only. If his bass goes to normal, then he has found the problem. If that doesn’t fix it, then he would have to entertain the possibility that the amp is defective out of the box, which, while possible, is however, improbable. At any rate that would prove that the problem lies elsewhere.

 

* One (remote) possibility is that he has 110 volt/60 Hz mains and the dealer accidentally shipped him a unit wired for 220 volt/50 Hz (not that the frequency matters. All audio companies selling internationally use power transformers that only have to be rewired on the primary side (the two primary windings in parallel for 110, and in series for 220) and which are designed to work equally well with both 50 or 60 Hz power). Looking on the back of the amp, next to the mains cord/connector should tell him whether his unit is wired for 110 or 220 - unless, of course,  the manufacturer wired it one way and labeled it another. In which case he needs to get his dealer involved.

[STC]

17 minutes ago, gmgraves said:

It is possible (though unlikely) that the manufacturer accidentally swapped the internal wiring of one channel at the speaker connectors

 

It is far more common than we would like to believe. 

[davide256]

So far I  see a lot of flailing around here.

 

1) the first miss is that the op hasn't provided the system and source solution in use...

2) secondly we should know what the room setup is for dimensions and type of construction

3) we should know how the speakers are positioned and if not floor standers, what stand solution is in use

4) need a musical reference point; what recording(s) are being used as basis for the OP's conclusion

 

Wouldn't even dream of trying to diagnose bass issues without this data at hand.

[fas42]

We are getting a bit of silly carry on from respondants ...

 

I'm reading the post saying, "I have a dedicated line for the hifi with 4mm simple cable. When i plug it to the wall i have a lot of bass...and from my line a have airly highs.why is that?!

 

i member before years i read some guys have the amp in the wall and the other to dedicated line. any thoughts?"

 

as referring to how power leads, and the mains are connected to his components. Yes, the nature of grounding arrangements can affect the SQ, and also part of the story is what the OP actually means by "lack of bass". Objectively, very little will alter - but subjectively the variation in the sense of the bass can be quite profound.

 

Since the poster is asking for "thoughts" on the matter - not the precise solution for his case - I merely offered what I find to be highly relevant to making signifcant changes to perceived quality. As they say, YMMV ... .

[One and a half]

1 hour ago, gmgraves said:

Bullpuckey! You are confusing the OP! There is nothing one can do that would change the quality of the mains power enough to affect the bass. Based on the OP’s description, the mains voltage would have to drop precipitously* in order change an amp’s performance that much from the demo unit to the purchased unit!

I find that the “out of phase” explanation is much more compelling than yours. It is possible (though unlikely) that the manufacturer accidentally swapped the internal wiring of one channel at the speaker connectors. The OP can easily check that by swapping the connection at ONE end of ONE channel (either at the speaker end or the amp end, whichever is more convenient). But change one end only, not both, and on one channel only. If his bass goes to normal, then he has found the problem. If that doesn’t fix it, then he would have to entertain the possibility that the amp is defective out of the box, which, while possible, is however, improbable. At any rate that would prove that the problem lies elsewhere.

 

* One (remote) possibility is that he has 110 volt/60 Hz mains and the dealer accidentally shipped him a unit wired for 220 volt/50 Hz (not that the frequency matters. All audio companies selling internationally use power transformers that only have to be rewired on the primary side (the two primary windings in parallel for 110, and in series for 220) and which are designed to work equally well with both 50 or 60 Hz power). Looking on the back of the amp, next to the mains cord/connector should tell him whether his unit is wired for 110 or 220 - unless, of course,  the manufacturer wired it one way and labeled it another. In which case he needs to get his dealer involved.

You may have forgotten about the unwanted harmonics on the AC network that work against speaker voice coils, eg the 5th.

Raif Smith measured harmonics on the input to speakers which bypassed the amp power supply.

 

Clean up harmonics either the hard way by measurement and make a lossy filter or use a transformer with a tight balanced secondary and the bass is restored. 

[gmgraves]

5 hours ago, davide256 said:

So far I  see a lot of flailing around here.

 

1) the first miss is that the op hasn't provided the system and source solution in use...

2) secondly we should know what the room setup is for dimensions and type of construction

3) we should know how the speakers are positioned and if not floor standers, what stand solution is in use

4) need a musical reference point; what recording(s) are being used as basis for the OP's conclusion

 

Wouldn't even dream of trying to diagnose bass issues without this data at hand.

Actually, none of that is really necessary because with the demo amp, the  OP had adequate bass. If all he did was replace the demo amp with the unit he’d purchased of the same make and model, then the amp and its connections are the ostensibly the only variable.

[gmgraves]

5 hours ago, One and a half said:

You may have forgotten about the unwanted harmonics on the AC network that work against speaker voice coils, eg the 5th.

Raif Smith measured harmonics on the input to speakers which bypassed the amp power supply.

 

Clean up harmonics either the hard way by measurement and make a lossy filter or use a transformer with a tight balanced secondary and the bass is restored. 

Again, the demo amp and the purchased amp are the same make and model. If it was the *“unwanted harmonics” on the mains that was robbing the OP of bass, it would have affected both examples of the amp in a similar fashion.

 

* Unwanted mains harmonics? I’m real skeptical.

 

 

 

 

 

[PeterSt]

11 minutes ago, gmgraves said:

Again, the demo amp and the purchased amp are the same make and model. If it was the *“unwanted harmonics” on the mains that was robbing the OP of bass, it would have affected both examples of the amp in a similar fashion.

 

George, I understand you like to be right on something (this is just human behavior I suppose), but the OP says that the problem is solved. And that per the means he described.

Shouldn't you proceed on that instead of continuing with air (of good smell ) ? I mean, if anything ?

[gmgraves]

32 minutes ago, PeterSt said:

 

George, I understand you like to be right on something (this is just human behavior I suppose), but the OP says that the problem is solved. And that per the means he described.

Shouldn't you proceed on that instead of continuing with air (of good smell ) ? I mean, if anything ?

Didn’t see the OP’s resolution. Sorry.

[PeterSt]

4 hours ago, gmgraves said:

Didn’t see the OP’s resolution. Sorry.

 

That's what I figured. The posts after it didn't really point in that direction. Mine ahead. 

[Ralf11]

I didn't see it either, but it never hurts to do many of the things mentioned above to improve the SQ (except maybe time & $$)