Dodgy amp?

WillyWarbucks

Standard Member
Joined
Sep 11, 2019
Messages
37
Reaction score
14
Points
11
Age
71
Location
Edinburgh
I've been buying a few things on ebay. a couple of passive satellite speakers, an active subwoofer and an integrated amp.

When I got everything set up, the volume of the bass coming out the sub feels a low compared to the speakers. I can crank the volume up on the amp and there's plenty of bass coming out, but at that point the speakers are way too loud.

If I connect the same speakers and sub to my other CD player with inbuilt amp, the level between the sub and the speakers sounds far more even. I can crank the volume at the back of the sub right up to a level that's too high infact. That's something that's impossible to do with the former configuration.

* I have noticed that the other output on the amp, the headphones out, is faulty. It only plays a mono signal (i think) and only in the right ear. Could it be that both those 2 separate outputs from the amp (the sub and the headphones) suffer from the same problem? I'm not sure how to check for that.

my equipment:

sub: https://images.crutchfieldonline.co...000/1950/products/2014/13/779/g779X200W-B.jpg

satellites: Cambridge Audio Minx Min 12 (Black) Ultra-compact satellite speaker at Crutchfield

amp: https://tibo-electronics.com/wp-content/uploads/2018/03/TI435-AMP-5710646002225-4.jpg

Thanks, any help appreciated!

* EDIT: I've just opened the amp up and the headphone output was just a loose connection
 
Last edited:
If you feel the sub is not outputting enough volume then turn the volume up on the sub only until you are satisfied. Trying to turn up everything with small speakers is going to induce clipping and possible damage to the speakers.
 
If you feel the sub is not outputting enough volume then turn the volume up on the sub only until you are satisfied. Trying to turn up everything with small speakers is going to induce clipping and possible damage to the speakers.
I might not have explained myself clearly. The problem is that I can only juuuuust about get an acceptable balance between sub and speakers if the sub is at max. There surely should be enough headroom to push past that a bit so that the sub is too loud (as is the case when testing the sub and speakers with my cd player)

Do subwoofer outputs differ that much between devices when it's just a non-amplified output? My cd player's sub output sounds (and I know it's really subjective) about twice the volume.
 
You provided a link to a photo of the Cambridge Minx 200, but that is an old model. The new model, for purposes of Specs, is the Minx 201 -


First where is the Sub Crossover Set. The tiny Cambridge front speakers are rated at 150hz on the low end, so that is roughly were you Sub Crossover should be set.

This is the nearest current equivalent -


Start with the Crossover at 150hz, then listen at a modest yet normal listening level, and bring the Sub Volume up until you feel it is reasonably matched with the Front Speakers.

I suspect there is an imbalance in your Setup. Once that is corrected, you can get a better sense of the system.

Keep in mind, you don't have any way of controlling the bass response of the Front Speakers. The Sub Controls only control the Sub. With FULL Bass Management, you can control the crossover to both Front and Sub, and limit low frequencies sent to the Front. But you don't have that.


The Front speakers are tiny 2.5" Drivers, there is a limit to how much you can expect from them.

There may be some ways of reducing the Frequencies going to the Front Speakers, but though not exceptionally expensive, do get to be a bit of a bother.


Also, WHERE ARE YOU LOCATED?

Steve/bluewizard
 
Last edited:
You provided a link to a photo of the Cambridge Minx 200, but that is an old model. The new model, for purposes of Specs, is the Minx 201 -

🤔

I provided a link to a photo of the Minx x200 because that's what I have.

Nevertheless, it makes little difference where I put the crossover on the sub's controls. At 150Hz, it sounds low in comparison to the speakers. At 200Hz, it sounds low in comparison to the speakers.
 
🤔

I provided a link to a photo of the Minx x200 because that's what I have.

Nevertheless, it makes little difference where I put the crossover on the sub's controls. At 150Hz, it sounds low in comparison to the speakers. At 200Hz, it sounds low in comparison to the speakers.


The Sub has three controls - Volume, Phase, and Crossover - though much of what I say depends on where the speakers are placed in proximity to each other. But assuming something close to a normal configuration -

- Set the PHASE to 0 (zero).
- Set the Crossover to ~150hz.
- Turn the Sub Volume DOWN, then with music playing at normal listening levels, bring the Sub Volume up until it sounds reasonably matched to the Front Speakers.
- Make ABSOLUTELY SURE that the Front Speakers are wired correctly. That in very case the AMP(+Red) goes to the SPEAKER(+Red). Nothing will suck the life out of speakers like one being wired backwards.


Answer all my questions.

Steve/bluewizard
 
The Sub has three controls - Volume, Phase, and Crossover - though much of what I say depends on where the speakers are placed in proximity to each other. But assuming something close to a normal configuration -

- Set the PHASE to 0 (zero).
- Set the Crossover to ~150hz.
- Turn the Sub Volume DOWN, then with music playing at normal listening levels, bring the Sub Volume up until it sounds reasonably matched to the Front Speakers.
- Make ABSOLUTELY SURE that the Front Speakers are wired correctly. That in very case the AMP(+Red) goes to the SPEAKER(+Red). Nothing will suck the life out of speakers like one being wired backwards.


Answer all my questions.

Steve/bluewizard

Hi, thanks for the help, I have every intention to answer all questions, but I think you edited your initial published post just a minute after I posted a reply.

"The Front speakers are tiny 2.5" Drivers, there is a limit to how much you can expect from them."
- The speakers sound good and I'm getting exactly what I expect from them in terms of volume and frequencies produced.

- I'm located in the UK

- I have set the phase to zero. I have set the crossover to 150Hz. I have played the music at normal listening levels and have attempted to gradually bring the sub's volume up to a matched sound level.

- I am unable to bring the sub's volume up to a matched sound level. The control knob maxes out. To my ears it's close, but a few dbs short of a matched sound level. I'm not a professional sound engineer but have done a fair amount of paid and unpaid audio mixing in my time so I feel like I know how loud the lower frequencies should be.

- The front speakers are wired correctly

- I also own a Denon Ceol RCD-N9 which I have tested with the same speakers and sub. It has an RCD subwoofer output just like the Tibo amp. I am able to turn the subwoofer's volume knob past acceptable levels of bass. With this setup - an acceptable level between speakers and sub sounds around 2/3 of the range of the sub's volume knob.
 
How old is the TIBO Amp? That's not a great amp to start with, and if it is a decade old, it might be time to consider a new amp. Though I do understand that this requires money, something that most of us are short on right now due to the world situation.

What you are hearing with the alternate amp sounds about right. What you are hearing with the TIBO does not sound right. I sounds like the Sub Out level is very low.

Steve/bluewizard
 
How old is the TIBO Amp? That's not a great amp to start with, and if it is a decade old, it might be time to consider a new amp. Though I do understand that this requires money, something that most of us are short on right now due to the world situation.

What you are hearing with the alternate amp sounds about right. What you are hearing with the TIBO does not sound right. I sounds like the Sub Out level is very low.

Steve/bluewizard
Only just bought the amp a couple weeks ago, 2nd hand.

Not a great amp true, but it's all I'm willing to spend and was thinking surely all it needed to do was low-level-line-out enough for an active sub. (some of this stuff is new to me, please correct techy things/terms I've misunderstood)

The amp itself seems in really good condition, the previous owner says they didn't use it. Of course they could be lying, but it's spotless and came with all original packaging and parts. Looks like Tibo only started selling the model around 3-4 years ago. So I can only presume it's quite new, not used much and looks good.

So, it looks like we're thinking it's either a design flaw from a cheap amp maker or this model has a bit of a dodgy sub-out? That kind of thing?
 
I'm pretty sure I can't really help here, but this has made me wonder about the Tibo's "sub out". Is it simply a "pre-amp out" equivalent, does anybody know? I've checked what specs I can find for the Tibo, but I can't find anything that says very much at all. I know it's a long shot, but is the Tibo by any chance doing any low-pass filtering for the sub out?
 
I'm pretty sure I can't really help here, but this has made me wonder about the Tibo's "sub out". Is it simply a "pre-amp out" equivalent, does anybody know? I've checked what specs I can find for the Tibo, but I can't find anything that says very much at all. I know it's a long shot, but is the Tibo by any chance doing any low-pass filtering for the sub out?
Good question. I've just attached the subout to my computer's audio interface with the left RCA cable and had a listen. It's definitely filtering out mids-high. Is this the reason it's 'quiet' ?
 
Good question. I've just attached the subout to my computer's audio interface with the left RCA cable and had a listen. It's definitely filtering out mids-high. Is this the reason it's 'quiet' ?
Could be - if its filter cut-off is significantly below the bottom end of the range of the front speakers, there could be a big gap in the upper bass.
 
At the moment I have just a single male to male RCA going from sub to LFE (left rca input) in the sub. Would there any signal boost using a single to stereo RCA and plugging in left and right sub inputs?
 
... is the Tibo by any chance doing any low-pass filtering for the sub out?

Most Amps do this, but the Low-Pass Filter is set pretty high up around 250hz at the top of the range for most Subs.

The TIBO has a single Sub-Out which is a Pre-Amp Out, meaning that the volume out of the Sub-Out should track the Volume Control on the Amp.

Also given, from what I understand, it worked fine on another Amp, that sort of points the finger at the TIBO Sub-Out level being too low.

The Left(LFE)/Right on the Subwoofer are simply Internally Summed into Mono inside the Sub. So, either input should be the same, as should using both inputs.

The same is true of the Sub-Out on the Amp, the left and right channels are summed together into a single Sub-Out MONO Channel.

Here is a critical question for the Original Poster. Obviously you are using the RCA Inputs on the Sub, but are you also using the RCA Audio-Out on the Sub?

In the Photo right next to each other are both Audio-In and Audio-Out. The Audio-Out ON THE SUB is worthless. Though that would most likely only be used for Active Speakers. But still worthless as it most certainly has a Low-Pass, but where the Low-Pass is set is unpredictable

g779X200W-B.jpg



Since, on the Sub, both Audio-In and Audio-Out are right next to each other, make sure you are connected to the Audio-IN.

You can try both the Audio-in Left and the Audio-In Right, I think they are both the same, but one might work better than the other.

Just a few thoughts.

Steve/bluewizard
 
Last edited:
Most Amps do this, but the Low-Pass Filter is set pretty high up around 250hz at the top of the range for most Subs.

The TIBO has a single Sub-Out which is a Pre-Amp Out, meaning that the volume out of the Sub-Out should track the Volume Control on the Amp.

Also given, from what I understand, it worked fine on another Amp, that sort of points the finger at the TIBO Sub-Out level being too low.

The Left(LFE)/Right on the Subwoofer are simply Internally Summed into Mono inside the Sub. So, either input should be the same, as should using both inputs.

The same is true of the Sub-Out on the Amp, the left and right channels are summed together into a single Sub-Out MONO Channel.

Here is a critical question for the Original Poster. Obviously you are using the RCA Inputs on the Sub, but are you also using the RCA Audio-Out on the Sub?

In the Photo right next to each other are both Audio-In and Audio-Out. The Audio-Out ON THE SUB is worthless. Though that would most likely only be used for Active Speakers. But still worthless as it most certainly has a Low-Pass, but where the Low-Pass is set is unpredictable

g779X200W-B.jpg



Since, on the Sub, both Audio-In and Audio-Out are right next to each other, make sure you are connected to the Audio-IN.

You can try both the Audio-in Left and the Audio-In Right, I think they are both the same, but one might work better than the other.

Just a few thoughts.

Steve/bluewizard
Yep, definitely only plugged into Audio-In on the sub. The manufacturer says the audio-outs are for a second subwoofer if wanted.

I haven't tried the right channel. Will give that a go tomorrow when my kid's not asleep.

I popped an email over to Tibo and got a reply:
"I suggest to buy a splitter from one phone out to two phono in. We had another customer where it solve the issue."

That sounds bizarre and more like the other customer he's taking about had a problem with their sub and not the amp. Nevertheless, I have a 1 RCA to 2 adapter coming in the next few days to check if that helps at all. But like you said, those left and right's just get summed together into a mono channel anyway.
 
But like you said, those left and right's just get summed together into a mono channel anyway.
It's possible they might get summed to twice the voltage? If I had two channels feeding into a sub's left and right inputs and I unplugged one, I'd expect the sound level to drop. Got to be worth a try, anyway.
 
Have you tried changing the phase on the sub when connected to the tibo?

If there is a low level filter, could you connect your computer or a phone to the amp and use a signal generator on the pc/phone to see what frequencies the sub receives? Sub should be capable of playing 39 to 200hz (according to cambridge website). If you cant hear the higher frequencies then the amp is perhaps filtering too low.

Or is it possible to see the voltage level of the tibo amp sub out and compare it to the denon, by using a multimeter? A low pre-out voltage will result in a quieter sub. If no multimeter you could test by using the pc to see the level / volume on the pc from each amp, if there If you do this I would set both amps with the same speakers to the same level in db by using a phone with a sound meter app.
 
Have you checked the bass tone control on the amp? It might be on its minimum setting.
 
Have you tried changing the phase on the sub when connected to the tibo?

If there is a low level filter, could you connect your computer or a phone to the amp and use a signal generator on the pc/phone to see what frequencies the sub receives? Sub should be capable of playing 39 to 200hz (according to cambridge website). If you cant hear the higher frequencies then the amp is perhaps filtering too low.

Or is it possible to see the voltage level of the tibo amp sub out and compare it to the denon, by using a multimeter? A low pre-out voltage will result in a quieter sub. If no multimeter you could test by using the pc to see the level / volume on the pc from each amp, if there If you do this I would set both amps with the same speakers to the same level in db by using a phone with a sound meter app.
Yep, tried the phase.

I do own a multimeter, but haven't a scooby how to use it really. But I'm sure I could find a youtube video explaining how to get the voltage reading from the subouts.

And yep, if I get a moment I'll try recording both amps on my computer.

Thanks for the suggestions.
 
Have you checked the bass tone control on the amp? It might be on its minimum setting.
Yep, actually boosted the bass up as high as possible and it helped, the bass is nearly there. It just irks me that it's maxxed out everywhere. I'm not a fan of heavily boosting EQs bands like that.
 
Have you tried changing the phase on the sub when connected to the tibo?

If there is a low level filter, could you connect your computer or a phone to the amp and use a signal generator on the pc/phone to see what frequencies the sub receives? Sub should be capable of playing 39 to 200hz (according to cambridge website). If you cant hear the higher frequencies then the amp is perhaps filtering too low.

Or is it possible to see the voltage level of the tibo amp sub out and compare it to the denon, by using a multimeter? A low pre-out voltage will result in a quieter sub. If no multimeter you could test by using the pc to see the level / volume on the pc from each amp, if there If you do this I would set both amps with the same speakers to the same level in db by using a phone with a sound meter app.

I've played a tone generator into the amp and out to my subwoofer and it's able to play a suitable range of frequencies. The filtering if there is much, on the Tibo sub out is quite minimal as you'll see in a minute. Here's an image of the recording I made of that: https://www.willarbuckle.com/misc/tibo_x200_freqs.png

I then set up the same song to play at the same (within a few dbs) volume and recorded the sub outputs of both my Denon and my Tibo. Here's a screenshot of those recordings, you can guess which is which: https://www.willarbuckle.com/misc/different_volumes.png

Listening back: the louder Denon does a way better job with the quality of sound too. It starts filtering out frequencies at much lower Hz and the actual sound quality seems superior too. I obviously didn't expect the Denon to lose a shootout against this Tibo, but I'm still surprised at the gap here. Mostly in terms of loudness, but the Tibo is basically only filtering out hi-hats and leaving the rest sounding like mud.

For your listening pleasure...
Tibo: Denon:
I think I need to buy a better amp :-/
 
@WillyWarbucks good tune. Also love the detail you have provided.

Wow thats a startling difference, the tibo is definitely outputting far too high frequencies through, which rules out filtering being too low and you losing a range of frequencies.

On the screen shot with recordings, does the waveform change when you adjust the volume on the tibo, as the sub output should be relative to the volume, if not something's not working and the output might be outputing a low signal at all times. If it does change with volume change then the line level is just lower than the denon. Would it be possible to get some sort of cheap line level amplifier, which should boost the signal to the sub? Maybe @BlueWizard can advise?

Have you tried contacting tibo to ask for info on the sub output? Its a shame the sub doesn't have a high level input, as you could use the speaker output as opposed to the sub output.
 
@WillyWarbucks good tune. Also love the detail you have provided.

Wow thats a startling difference, the tibo is definitely outputting far too high frequencies through, which rules out filtering being too low and you losing a range of frequencies.

On the screen shot with recordings, does the waveform change when you adjust the volume on the tibo, as the sub output should be relative to the volume, if not something's not working and the output might be outputing a low signal at all times. If it does change with volume change then the line level is just lower than the denon. Would it be possible to get some sort of cheap line level amplifier, which should boost the signal to the sub? Maybe @BlueWizard can advise?

Have you tried contacting tibo to ask for info on the sub output? Its a shame the sub doesn't have a high level input, as you could use the speaker output as opposed to the sub output.
Yep the Tibo's sub-out increases as I turn the main volume of the amp. I can turn the amp right up so that the bass level is at a decent volume... but the problem is that the speakers are then far too loud.

I emailed Tibo and got the reply - "I suggest to buy a splitter from one phone out to two phono in."

I know it's a cheap amp (ÂŁ120) but I don't think the price matches the quality. You can buy very decent equipment these days for not too much.
 
Sounds like @oscroft suggestion might work then, have you got a splitter to try?
 

The latest video from AVForums

TV Buying Guide - Which TV Is Best For You?
Subscribe to our YouTube channel
Back
Top Bottom