Lack of bass

[basite]

here's the problem, i've got Advents with new 12" woofers(which you probably all know by now) and when i sit in my normal listening place i have too less bass, with too less bass i mean that i can hear the frequencies, but i don't get that *punch* feeling, when i sit between my speakers, i have the right amount of bass, but too less treble, when i am besides my speakers, i have too much bass and too less treble, what could this be?

these were some things i am thinking:
1) the speakers are all setup wrong, and i sit in the wrong place, the speakers are 2 meters (6 feet) apart from eachother, and they are in the same distance from me,
2) the speaker cabinet is too small for the woofers, originally the advents had 10" woofers, now they have 12" woofers,
3) since the new woofers are more powerfull and bigger, and the crossover is still the same, the whole power distribution is messed up and therefore, the woofers have too less output, compared to the tweeters, the woofers are 12", 250watts at 8ohm
4) the woofers just can't handle the extremely low frequencies, (which seems very unlikely)

note that when i turn the volume up, that the punch does come in, and when i turn the bass up to +5 db(at the tonal control) it get's better.

any solutions/sugesstions??

Greetz,
Bert Hellemans

[Dusty Chalk]

The only thing I can think of (besides what you have already listed) is that maybe one of the woofers is out of phase, and therefore cancelling the other.

[basite]

The only thing I can think of (besides what you have already listed) is that maybe one of the woofers is out of phase, and therefore cancelling the other.


it's only one woofer per speaker, so i don't think that would be the case.
Here's another pic to look at.

[basite]

since i don't have a huge room, could it be overkill??

[JohnMichael]

it's only one woofer per speaker, so i don't think that would be the case.
Here's another pic to look at.



What Dusty is talking about is when you attached the wires to the back of the woofers maybe one is hooked up correctly and the other not. In your left speaker if you put the positive wire on the positive speaker connection and neg on neg but then in the right you put the positive wire on the neg connection and the neg on the pos that is out of phase. What you want to do is to remove one woofer and reverse how they are hooked up, reinstall the woofer and then listen for the bass. If they are now in phase the bass should return. You should also have better imaging with the woofers in phase to each other. Woofers can be mismarked from the factory so trust your ears.

[bfalls]

I believe Dusty understand there's only one woofer in each cabinet. If the two woofers are out-of-phase with each other the signals will cancel. To verify, place the two speakers face to face with each other a couple of feet apart. With your head in the middle listen to music with bass and note the bass level. Reverse the connections on one speaker to see if the bass increases. If it does the woofers are out of phase. Once you've determined they're out of phase, you'll need to determine where your wiring is different, internal or external. Since you've modified the speakers, I wouldn't be surprised if something was backward.

Items two and three on your list are also possible. Box volume is important to low frequency response. The larger the box the lower it can go. Also if the Xover was designed for a certain speaker with a specific voice coil resistance and inductance, it could effect impedance, thus affecting output.

[basite]

Items two and three on your list are also possible. Box volume is important to low frequency response. The larger the box the lower it can go. Also if the Xover was designed for a certain speaker with a specific voice coil resistance and inductance, it could effect impedance, thus affecting output.


the original woofers were 6 ohm's i think, these are 8 ohm, so that could be a problem;
i'm now checking for incorrect wiring.

[basite]

wiring seems correct, i did do something else, inside the cabinet, there was alot of stuff to absorb the shocks, i replaced some to the bottom of the cabinet, now there is a little more bass, which is good, only the really really low sounds still seem to fade away al little, but that could only be solved with a sub i guess, maybe i will replace the current woofers with less powerfull ones (let's say 150 watts instead of 250) or look out for woofers rated at 6 ohm, that could solve a bit, besides that, next year, i will be investing in new speakers, or a power amp, i think that would do alot too. then the mighty Advents will retire and will be used in the radio system or something.

[Dusty Chalk]

Well, no actually all of that makes perfect sense. You replaced a woofer with another one that has completely different characteristics (including, most probably, and most importantly, sensitivity), but you didn't change anything about the crossover. So now the speaker is "lopsided". If it's less sensitive than before, then you're going to get less bass at pretty much any volume.

I'm really not sure what the solution is. Here are several things you can do:

- replace the woofer again, this time with something with the same characteristics;
- take the woofers out (or leave them in), but amplify them with a different amplifier ("bi-amp" them), but set the levels different, to compensate for the different sensitivities -- you may need an entirely new crossover if the current one doesn't support biamping (separate sections for woofer and upper frequencies);
- leave the woofers in, get a subwoofer -- still going to be a minor suckout in the upper bass (where the sub doesn't cover);
- compensate for the less sensitivity of the woofers in the crossover -- make the upper region less sensitive;
- other ideas?

[basite]

hmmm, interesting, upper bass is quite good, but since i'm going to buy new speakers in a year (more likely to be several years) which probably won't reach 20 hz (since those speakers that can, are too expensive) a sub would be a good idea, i could save for that and get myself a good one, that would also be the better solution, since a new crossover would only get me into more trouble, and the original one is quite good too, so i won't replace them,

so for now, the idea is to get a sub.

Greetz,
Basite.

[Dusty Chalk]

...upper bass is quite good...Well, in that case, I might be wrong in my conclusion. Did you try running a frequency sweep? If it starts out low and quiet, and gets louder through the crossover as the frequency goes up, then I'm still probably right. Check both speakers independently (balance hard left and hard right, or, if you don't have a balance, disconnect the input to the amp from one channel, then the other).

[anamorphic96]

Try going to a speaker specialist and see if ther are woofers made that are compatible with your speaker. Or go and have the old woofers reconded if possible.

Sounds like your current woofers are not compatible with the cabinet. You could also do some searches online and see if anyone has suggestions from other sights. Try a search for speaker specialists and such. Or compatible Advent woofer replacements.

[jrhymeammo]

For free frequewncy sweep test, try this link.
http://forums.audioreview.com/showthread.php?t=17021&highlight=pink+noise
It's post #6. Be sure to thank Florian.

-JRA

[basite]

Sounds like your current woofers are not compatible with the cabinet. You could also do some searches online and see if anyone has suggestions from other sights. Try a search for speaker specialists and such. Or compatible Advent woofer replacements.

not compatible with the cabinet, do you mean that the cabinet is too small??
i searched for advent woofers, but it seems that advent only used 8, 9 and 10" woofers,



For free frequewncy sweep test, try this link.
http://forums.audioreview.com/showth...ght=pink+noise
It's post #6. Be sure to thank Florian.

-JRA

sure, thanks too you and to Florian,:cornut:


i've done the test frequencies, from off 63 hz it gets louder, anything below that is silent, you hear them, but not really loud.
speakers are crossed at 1.5khz

possible solutions are (to me)
-getting a new woofer
-getting a subwoofer (more likely to happen) and since my new speakers (in a few years) will probably be wharfedales, i was looking at this sub.

http://www.wharfedale.co.uk/model.php?model_id=111&finish=10

greetz,
Basite.

[anamorphic96]

Then go with the 10" replacement for your model.
The driver sounds like its to big for the cabinet. You might want to get the specs of the driver and cabinet and check with a specialist. But it does sound like you need a different driver judiging by your sweeps.

[yogo]

The original woofer was designed or chosen to work in that cabinet size.

Every speaker has certain characteristics. These characteristics have to be accounted for when building a speaker system. You can't just throw any speaker in a cabinet and expect it to work correctly.

What you have is a closed box air suspension speaker system. The speaker you have installed may be made to be in a ported system as opposed to an air suspension system.

If it is an air suspension speaker there may be not enough air in that size box to allow the new woofer to move enough in the lower frequencies to produce low bass. That may be why you are missing bass as the freq's get lower. Many other factors such as impedance may also contribute to poor sound such as an imbalance volume level with the tweeter.

I would buy an original replacement speaker or replace the surrounds on the old pair of woofers.
There are surround kits out there for like 25 bucks. I did my Baby Advents and it was an easy job.

Unless you're a speaker designer I wouldn't try to redesign any already optimized speaker. You'll be wasting your time...

[royphil345]

Don't think he'll be able be able to put the original 10" in the 12" hole guys!!!

Yes, The larger driver would likely require a larger cabinet or port for optimum bass response.

Yes, If you replace a 6 ohm woofer with an 8 ohm woofer, any other drivers in the system will get louder in comparison.

You could easily add an L-pad volume control for each tweeter, allowing you to adjust the balance between the woofer and tweeter on your speakers. You could try simply adding a 2 ohm non-inductive resistor to the positive tweeter lead instead, if you're sure you went from a 6 to an 8 ohm woofer and you don't want adjustable controls. Either way, you'd basically be raising the resistance of the tweeter to match the higher resistance of the replacement woofer. Adding resistance will lower the crossover frequency of the capicitor(s) to your tweeter slightly, probably not significantly. A lower crossover would be better than higher considering the larger woofer anyway. Adding a resistor / L-pad should be worthwhile for you. Would probably improve your soundstage / mid-range considerably, even if the woofer isn't perfect for the cabinet.

Definitely make sure your woofers have been installed correctly and in phase, and that your speaker wires are hooked up properly and in phase. Though... it does seem like the woofer change is causing the bright sounding speakers in your case...

[basite]

well, i tried something to rule out some things,
I used my dad's subwoofer (b&w asw600) and placed it in my room.
according to the conclusions we made in this post, i should be smashed into the nearest wall because the sub is pretty big, sure this whould have happened in the right room, but here it didn't, instead, it did... Nothing at all,

the sub (and the speakers) were giving all they had (volume was halfway open on sub), and where i sat, nothing happened,
i tried 3 different placings: 1) between the speakers, this did nothing, really really nothing
2) against the wall to my left side, this did a little little bit, but
actually too less to mention,
3) i suddenly remembered what the dealer said when we bought
the sub, place it where you have good bass, so i did, (hard to
describe, please look at the third photo) this did something
noticable: the whole room started to shake and there was a
little increasement in the bass,

after that i kindof concluded that it had something to do with the room itselves, i made a drawing in paint so you can look a bit too. (4th pic)

[basite]

besides rebuilding the room to something more audio friendly, are there any other solutions??

could it be that the woofers in the advents are cancelling the sub somehow??
if that is, that would mean that the woofers are out of phase.
if not,
would a down firing subwoofer help?

Thnx,
Basite.

[anamorphic96]

I would start over and change the woofers to something compatible with the Advents. There really is no other way around this issue. The driver you put in is not compatible and causing problems.

I just did a Google search and 5 seconds later came up with this link. Could be a start. There are many companies that specialize in repair of older Advents. It even looks like they have replacements for your large Advents for 50.00. Not a bad deal if ask me.

http://layneaudio.hypermart.net/repair.htm

[JoeE SP9]

The replacement woofers you are using were designed for a ported cabinet. They will never work properly in a sealed (acoustic suspension) cabinet. You need to replace them with woofers designed for acoustic suspension type cabinets. If you do that you should replace any stuffing you have removed. Placing the wrong size and type of woofer in those cabinets has not been any help in your search for better sound. If you replace the current 12" woofers you will probably have to go with 12"s instead of tens like the cabinet size was designed for. Just make sure you get woofers designed for sealed box placement.
When replacing individual speakers of a "system" you must replace them with drivers that are compatible with the speaker as it was designed to be used. You can't just throw any driver you find at it and expect it to work properly.:idea:

[royphil345]

Sounds like you're getting bass because of the room shaking... What you're most likely missing is the flat, linear frequency response required for a "solid", "punchy" sound. Adding a resistor to the tweeters would help. There is definitely a driver / box mismatch. This would mostly effect your lowest frequencies though. If you get the crossover smoother between the woofer and tweeter, bring out the mids and upper bass, the speakers should sound MUCH better with a sub and probably OK on their own, minus great response at the lowest frequencies.... You may have somewhat of a "hole" in the midrange due to the larger woofer not being able to play frequencies high enough to blend with the tweeter properly. Adding a resistor / L-pad to the tweeter wiil also lower your crossover frequency a bit. If the high frequency driver is capable of playing a little lower, it will. Might lower the power rating of your speaker a bit by increasing the frequency range of the tweeter.

[PeruvianSkies]

Ok, I hope this does not come across as being mean-spirited, so here goes...

I am looking at your setup and your information along with the responses, which have alll been highly knowledgable and very interesting, but my question is simple: Wouldn't it just be easier to get something that is good straight out of the box instead of tweaking around with what you have? I mean, it seems like you are causing more problems by messing around with parts here and there and it would all be solved by getting something that sounds great straight from the getgo.

Do you have a budget plan in mind for when you upgrade in the near future as you mentioned? It might be smart to reallly think through your options based on certain financial stipulations and really attack this thing sharply. I think that many of us would agree that we wish we would have planned for things a bit better over the years when it comes to components etc etc.

[royphil345]

You're right, of course...

Made my recommendation because it's cheap to do, a good learning experience, and I think it really would make a big difference as far as making the speakers listenable until they could be replaced. Might not sound bad at all with the crossover smoothed out and a sub. A 12" woofer is pretty big for a 2-way system where the high frequency driver isn't a good-sized horn or something though... Might be a pretty big "hole" in the mids, causing the speakers to sound "thin" no matter what...

[basite]

The replacement woofers you are using were designed for a ported cabinet. They will never work properly in a sealed (acoustic suspension) cabinet. You need to replace them with woofers designed for acoustic suspension type cabinets. If you do that you should replace any stuffing you have removed. Placing the wrong size and type of woofer in those cabinets has not been any help in your search for better sound. If you replace the current 12" woofers you will probably have to go with 12"s instead of tens like the cabinet size was designed for. Just make sure you get woofers designed for sealed box placement.
When replacing individual speakers of a "system" you must replace them with drivers that are compatible with the speaker as it was designed to be used. You can't just throw any driver you find at it and expect it to work properly.:idea:

how do you know a driver is made for a ported cabinet or a sealed cabinet??
and i didn't do the new woofers, my dad did, i was lik 5 years old then.



Ok, I hope this does not come across as being mean-spirited, so here goes...

I am looking at your setup and your information along with the responses, which have alll been highly knowledgable and very interesting, but my question is simple: Wouldn't it just be easier to get something that is good straight out of the box instead of tweaking around with what you have? I mean, it seems like you are causing more problems by messing around with parts here and there and it would all be solved by getting something that sounds great straight from the getgo.

Do you have a budget plan in mind for when you upgrade in the near future as you mentioned? It might be smart to reallly think through your options based on certain financial stipulations and really attack this thing sharply. I think that many of us would agree that we wish we would have planned for things a bit better over the years when it comes to components etc etc.


how do you mean "out of the box"
i probably upgrade next summer, when i hope to have some work,
the budget will be from 500€ (hopely more) to 1000€ the upgrades (which will be speakers) i thought of will probably be wharfedale diamond 9.5 or 9.6 speakers or a focal speaker, not sure which one fits the budget though. keep in mind that i'm only 16 so money is hard to get.

[basite]

Sounds like you're getting bass because of the room shaking... What you're most likely missing is the flat, linear frequency response required for a "solid", "punchy" sound. Adding a resistor to the tweeters would help. There is definitely a driver / box mismatch. This would mostly effect your lowest frequencies though. If you get the crossover smoother between the woofer and tweeter, bring out the mids and upper bass, the speakers should sound MUCH better with a sub and probably OK on their own, minus great response at the lowest frequencies.... You may have somewhat of a "hole" in the midrange due to the larger woofer not being able to play frequencies high enough to blend with the tweeter properly. Adding a resistor / L-pad to the tweeter wiil also lower your crossover frequency a bit. If the high frequency driver is capable of playing a little lower, it will. Might lower the power rating of your speaker a bit by increasing the frequency range of the tweeter.


this l-pad/resistor thing, on the back of the advent there is a switch, named "high frequency control", it has 3 positions: normal, decrease, increase normal is 0db, decrease is -3db and increase is +3db, can it be that this is kind of the same thing??
if so, would it help if i set it to "decrease"??

[Dusty Chalk]

Yes, and yes.

[basite]

ok, done, the balance between high tones and bass tones is better, only thing to do is to get new drivers, if i can find 12" woofers for sealed cabinets...

[basite]

Thnx guys btw :cornut:


Greetz,
Basite.

[Dusty Chalk]

ok, done, the balance between high tones and bass tones is better, only thing to do is to get new drivers, if i can find 12" woofers for sealed cabinets...Try to get a closer match on both impedance and sensitivity this time.